Kuwait University
Chemical Engineering Department
ChE491: PLANT DESIGN
Report(3): Equipment Design
Production of
Acetaldehyde
Written By:
Group Two:
Abdulhadi K. Alsaleh
Abdullah S. Alshemali
Abdulrhman S. Almutairi
Hamed M. Alazmi
Isam E. Elbadawi
Instructor:
Prof. Mohammed Fahim
Teaching Assistance:
Eng. Yusuf Ismail
Table of Contents
Introduction.................................................................................................................... 1
1. Equipment Description and Theory ........................................................................... 2
1.1 Reactor ................................................................................................................. 2
1.2 Absorber ............................................................................................................... 7
1.3 Distillation column ............................................................................................. 18
1.4 Heat Exchangers ................................................................................................ 26
1.5. Flash Separator (V-L Separator) ...................................................................... 41
1.6. Compressor K-101 ............................................................................................ 45
1.7. Pumps ................................................................................................................ 48
1.8. Valves ................................................................................................................ 55
2. Equipment Calculation ............................................................................................ 59
2.1. Abdullah’s Design ............................................................................................. 59
2.1.1. Reactor (CRV-100) ..................................................................................... 59
2.1.2. Flash separator........................................................................................... 64
2.1.3. Compressor ................................................................................................. 66
2.1.4. Heat Exchanger (Cooler E-101)................................................................. 69
2.2. Abdulhadi’s Design ........................................................................................... 78
2.2.1. Distillation Column (T-100) ....................................................................... 78
2.2.2. Distillation Column (T-102) ....................................................................... 83
2.2.3. Heat Exchanger (Heater E-103)................................................................. 88
2.3 Abdulrhman’s Design......................................................................................... 98
2.3.1. Heat Exchanger (Heater E-100)................................................................. 98
2.3.2. Heat Exchanger (Cooler E-102)............................................................... 108
2.3.3. Heat Exchanger (Cooler E-104)............................................................... 118
2.3.4. Valve (VLV-100) ....................................................................................... 128
I
2.4. Hamed’s Design .............................................................................................. 130
2.4.1. Absorber (T-101) ...................................................................................... 130
2.4.2. Pump (P-100) .......................................................................................... 136
2.4.3. Pump (P-101) .......................................................................................... 138
2.5. Isam’s Design .................................................................................................. 140
2.5.1 Distillation Column (T-103) ...................................................................... 140
2.5.2 Distillation Column (T-104) ...................................................................... 147
2.5.3 Pump P-102 ............................................................................................... 154
2.5.4 Valve (VLV-101) ........................................................................................ 156
3. References .............................................................................................................. 158
4. Appendix (Design Figures) .................................................................................... 160
4.1Column Design Figures .................................................................................... 160
4.2 Cooler & Heater Design Figures ..................................................................... 169
| P a g e II
Introduction
In this report, the equipments in the Acetaldehyde production from Ethanol process flow
sheets have been designed; along with estimating the cost of each equipment. The resulted data
are presented with detailed design procedures. Furthermore, Excel and Poly math program are
created to calculate the design parameters.
Equipments List
1. Reactor
2. Absorber
3. Distillation Columns
4. Heat Exchangers
5. Flash Separator
6. Compressor
7. Pumps
8. Valves
1
1. Equipment Description and Theory
1.1 Reactor
Chemical reactors are vessels designed to contain chemical reactions. The design of a
chemical reactor deals with multiple aspects of chemical engineering. Chemical engineers design
reactors to maximize net present value for the given reaction. Designers ensure that the reaction
proceeds with the highest efficiency towards the desired output product, producing the highest
yield of product while requiring the least amount of money to purchase and operate. Normal
operating expenses include energy input, energy removal, raw material costs, labor, etc. Energy
changes can come in the form of heating or cooling, pumping to increase pressure, frictional
pressure loss etc.
Continuous packed bed reactors
Packed bed reactors (PBR) used in chemical reaction. These reactors are tubular and are
filled with solid catalyst particles, most often used to catalyze gas reactions. The chemical
reaction takes place on the surface of the catalyst. The advantage of using a packed bed reactor is
the higher conversion per weight of catalyst than other catalytic reactors. The reaction rate is
based on the amount of the solid catalyst rather than the volume of the reactor.
A continuous packed bed reactor has the following advantages over a batch packed bed reactor:
1.
2.
3.
4.
Easy, automatic control and operation
Reduction of labor costs
Stabilization of operating conditions
Easy quality control of products
Theory used in PBR Calculation
Our main reaction
|Page2
Arrhenius equation
Where:
k : rate constant of chemical react
T : Temperature of reaction (in K)
Ea : activation energy of the reaction
R : Gas Constant
A : the pre exponential factor
BPR equation
dx  rA

dW FA0
Where:
x
: conversion of reaction
W : weight of catalyst
rA : reaction rate
FA0 : Initial flow rate of component A
Reaction rate equation
 r  k ( P )^ 2
A
A
Where:
rA : reaction rate
k : rate constant of chemical reaction
PA : outlet pressure of component A
|Page3
1  x  T0  P 
P P
A
A0 1  x  T  P 
  0 
Where
PA : outlet pressure of component A
PA0 : inlet pressure of component A
T0 : The inlet temperature.
T
: The outlet temperature.
P : The outlet pressure of reactor
P0 : The inlet pressure of reactor
x : Conversion of the reaction
 : The change in total number of moles for complete conversion per total number of moles fed
to the reactor
  y A0
Where
y A0 : Entering mole fraction of A.
 : Change in total number of moles per mole of reacted A.
 : The change in total number of moles for complete conversion per total number of moles fed
to the reactor.
|Page4
Realation between weight of catalyst and volume of raector
Wcat
(1   )  bulk
V
Where
V
: Volume of the reactor
W : Weight of the catalyst
 : Bulk density of catalyst
 : Porosity (amount of void in the catalyst)
Volume of cylinder
V 

4
D2 L
Where
D : Diameter of the reactor
L : Length of reactor
A
V
H
Where:
A Area of the reactor.
H Height of the reactor.
|Page5
t
Pri
 Cc
SEj  0.6 P
Where:
t : Shell thickness (in)
P : Maximum allowable internal pressure (psig)
ri : Internal radius of shell before allowance corrosion is added (in)
E j : Efficiency of joints
S : Working stress (psi)
Cc : Allowance for corrosion (in)
Tlm 
(T1  t 2 )  (T2  t1 )
(T  t )
ln 1 2
(T2  t1 )
Where:
- TLM  Log means Temperature.
- T1  Inlet shell side fluid temperature & T2  Outlet shell side fluid temperature (oC).
- t1  Inlet tube side temperature (oC) & t 2  Outlet tube temperature (oC).
Tm  Ft Tlm

Where:
- Tm  True temperature difference. & Ft  Temperature correction factor.
 A
Q
UTm
Where:
- A  Provisional area in m2. & Q  Heat load in W.
-U = overall heat transfer coefficient (W/m2 oC)
|Page6
1.2 Absorber
Gas absorption is one of the major mass transfer unit operations used in the separation or
purification of gas mixtures. The operation is carried out by contacting the gas with a liquid
solvent, usually in a packed or plate column. The regenerated solvent is recycled to the
absorption column.
One of the applications of absorption technology is the purification of various process streams to
prevent pollution, corrosion, catalyst poisoning or condensation in subsequent low temperature
treatment. When the two contacting phases (gas and liquid), this operation called absorption. A
solute or several solutes are absorbed from the gas phase into the liquid phase in absorption. This
process involves molecular and turbulent diffusion or mass transfer of solute through a stagnant,
non-diffusing gas into a stagnant liquid.
|Page7
Plate contactors
Cross-flow plates are the most common type of plate contactor used in distillation and
absorption columns. In a cross-flow plate the liquid flows across the plate and vapor up through
the plate. There are three principal types of cross-flow tray are used, classified according to the
method used to contact the vapor and liquid.
a) Sieve plate
Sieve trays are simply metal plates with holes in them. Vapor passes straight upward through the
liquid on the plate. The arrangement, number and size of the holes are design parameters.
Because of their efficiency, wide operating range, ease of maintenance and cost factors, sieve
and valve trays have replaced the once highly thought of bubble cap trays in many applications.
b) Bubble-cap plate
A bubble cap tray has riser or chimney fitted over each hole, and a cap that covers the riser. The
cap is mounted so that there is a space between riser and cap to allow the passage of vapor.
Vapor rises through the chimney and is directed downward by the cap, finally discharging
through slots in the cap, and finally bubbling through the liquid on the tray.
|Page8
c)
Valve plate
In valve trays, perforations are covered by lift able caps. Vapor flows lifts the caps, thus
self-creating a flow area for the passage of vapor. The lifting cap directs the vapor to flow
horizontally into the liquid, us providing better mixing than is possible in sieve trays.
Liquid and Vapor Flows in a Tray Column
The next few figures show the direction of vapor and liquid flow across a tray, and across a
column.
Each tray has two conduits, one on each side, called ‘down comers’. Liquid falls through the
down comers by gravity from one tray to the one below it. The flow across each plate is shown
in the above diagram on the right.
|Page9
A weir on the tray ensures that there is always some liquid (holdup) on the tray and is designed
such that the the holdup is at a suitable height, e.g. such that the bubble caps are covered by
liquid.
Being lighter, vapor flows up the column and is forced to pass through the liquid, via the
openings on each tray. The area allowed for the passage of vapor on each tray is called the active
tray area.
As the hotter vapor passes through the liquid on the tray above, it transfers heat to the liquid. In
doing so, some of the vapor condenses adding to the liquid on the tray. The condensate, however,
is richer in the less volatile components than is in the vapor. Additionally, because of the heat
input from the vapor, the liquid on the tray boils, generating more vapors. This vapor, which
moves up to the next tray in the column, is richer in the more volatile components. This
continuous contacting between vapor and liquid occurs on each tray in the column and brings
about the separation between low boiling point components and those with higher boiling points.
Tray Designs
A tray essentially acts as a mini-column, each accomplishing a fraction of the separation task.
From this we can deduce that the more trays there are, the better the degree of separation and that
overall separation efficiency will depend significantly on the design of the tray.
Trays are designed to maximize vapor-liquid contact by considering the liquid distribution and
the vapor distribution on the tray. This is because better vapor-liquid contact means better
separation at each tray, translating to better column performance. Fewer trays will be required to
achieve the same degree of separation. Attendant benefits include less energy usage and lower
construction costs.
| P a g e 10
Packing
There is a clear trend to improve separations by supplementing the use of trays by additions of
packing. Packing are passive devices that are designed to increase the interfacial area for vaporliquid contact. The following pictures show 3 different types of packing.
These strangely shaped pieces are supposed to impart good vapor-liquid contact when a
particular type is placed together in numbers, without causing excessive pressure-drop across a
packed section. This is important because a high pressure drop would mean that more energy is
required to drive the vapor up the distillation column.
| P a g e 11
Selection of solvent
The essential elements of solvent selection criterion are feed gas characteristics (composition,
pressure, temperature, etc.) and the treated gas specifications (i.e. the process requirements).
These two elements provide a preliminary evaluation of the solvent working capacity which
may, however, be influenced by several other elements such as solvent characteristics and
operation issues of the separation process.
Absorber Design Assumptions
Plate spacing = 0.6 m
Sieve plate
Weir height = 5 mm
Hole diameter = 50 mm
Plate thickness = 5 mm
Efficiency = 75%
Flooding = 85%
Turn down = 70%
Material of absorber carbon steel
| P a g e 12
Equations
FLV
L

V
 v

 L



0.5
Where:
FLV = Liquid vapor flow rate.
L = Liquid flow rate.
V = Vapor flow rate.
 (   V ) 

U f  K 1  L
V


0.5
Where:
Uf = Flooding velocity.
K1 = Constant.
UV  Percentage Flooding x U f
Where:
Uv = Actual velocity.
MwtV
Vmax 
V
Where:
Vmax = Maximum volumetric flow rate.
MwtV = Vapor molecular weight.
Anet 
Vmax
UV
Anet = Net area required.
| P a g e 13
4

D   Anet 


0.5
Where:
D = Diameter.
max volumetric liquid rate 
LxMwt
L
Where:
L = Liquid flow rate.
AC 

4
D2
Where:
AC = Column area.
An  AC  Ad
Where:
An = Net area.
Aa  Ac  2 Ad
Aa= Active area.
Ah  0.1xAa
Ah= Hole area.
weir length  0.75D
| P a g e 14
2
 max liquid rate  3

max how  750

xweir
length
 L

2
 min liquid rate  3

min how  750

xweir
length
 L

Where:
how = Weir crest.
U h (min) 
K 2  0.9(25.4  hole diameter)
 0.5
Where:
Uh = Vapor velocity.
actual min . vapor velocity 
min . vapor rate
Ah
Where:
Ah = Hole area.
U
hd  51 h
 Co



2
 V

 L



Where:
hd = Pressure drop through dry plate.
Co = Orifice coefficient.
| P a g e 15
hr 
12.5 x10 3
L
Where:
hr= Residual head.
hap  hw  10
Where:
hap= Height of bottom edge of apron above plate.
hw= Weir height.
area under apron Aap  weir lengthxhap
 max . liquid rate 

hdc  166



xA
L
ap


2
hb  hw  hdc  ht  how
Where:
hb = Dack-up in downcomer.
tr 
hb xAdx L
Lwd
Where:
tr = Downcomer residence time.
Lwd = Minimum liquid flow rate.
| P a g e 16
UV 
volumetric flow rate
An
Pxri


  CC
t  
 SxEj  0.6 xP 
Where:
t = Thickness.
P = Pressure.
r = Radius.
S = Working stress.
Ej = Efficiency of joints.
CC = Allowance for corrosion.
| P a g e 17
1.3 Distillation column
Distillation is a process in which a liquid or vapor mixture of two or more substances is
separated into its component fractions of desired purity, by the application and removal of heat.
Main Components of Distillation Columns
Distillation columns are made up of several components, each of which is used either to transfer
heat energy or enhance material transfer. A typical distillation contains several major
components:
-a vertical shell where the separation of liquid components is carried out
-column internals such as trays/plates and/or packings which are used to enhance component
separations
-a reboiler to provide the necessary vaporization for the distillation process
-a condenser to cool and condense the vapor leaving the top of the column
- a reflux drum to hold the condensed vapor from the top of the column so that liquid (reflux) can
be recycled back to the column The vertical shell houses the column internals and together with
the condenser and reboiler, constitute a distillation column. A schematic of a typical distillation
unit with a single feed and two product streams is shown below:
| P a g e 18
Types of distillation columns
There are many types of distillation columns, each designed to perform specific types of separations,
and each design differs in terms of complexity. One way of classifying distillation column type is to
look at how they are operated. Thus we have:
1- Batch Columns
In batch operation, the feed to the column is introduced batch-wise. That is, the column is charged with
a 'batch' and then the distillation process is carried out. When the desired task is achieved, a next batch
of feed is introduced.
2-Continuous Columns
In contrast, continuous columns process a continuous feed stream. No interruptions occur unless there
is a problem with the column or surrounding process units. They are capable of handling high
throughputs and are the most common of the two types. We shall concentrate only on this class of
columns.
Column Internals
Trays and Plates The terms "trays" and "plates" are used interchangeably. There are many types of tray
designs, but the most common ones are:
Bubble cap trays:
A bubble cap tray has riser or chimney fitted over each hole, and a cap that covers the riser. The cap is
mounted so that there is a space between riser and cap to allow the passage of vapor. Vapor rises
through the chimney and is directed downward by the cap, finally discharging through slots in the cap,
and finally bubbling through the liquid on the tray.
Valve trays:
In valve trays, perforations are covered by liftable caps. Vapor flows lift the caps, thus self-creating a
flow area for the passage of vapor. The lifting cap directs the vapor to flow horizontally into the liquid,
thus providing better mixing than is possible in sieve trays.
| P a g e 19
Sieve trays:
Sieve trays are simply metal plates with holes in them. Vapor passes straight upward through the liquid
on the plate. The arrangement, number and size of the holes are design parameters. Because of their
efficiency, wide operating range, ease of maintenance and cost factors, sieve and valve trays have
replaced the once highly thought of bubble cap trays in many applications.
Packings
There is a clear trend to improve separations by supplementing the use of trays by additions of
packings. Packings are passive devices that are designed to increase the interfacial area for vapor-liquid
contact. The following picture show different types of packings.
These strangely shaped pieces are supposed to impart good vapor-liquid contact when a particular type
is placed together in numbers, without causing excessive pressure-drop across a packed section. This is
important because a high pressure drop would mean that more energy is required to drive the vapor up
the distillation column.
| P a g e 20
Packings Versus Trays Columns
Packed Columns
Trayed Columns
Plate-design procedure
1. Collect, or estimate, the system physical properties.
2. Calculate the maximum and minimum vapor and liquid flow-rates, for the turn down ratio required.
3. Select trial plate spacing.
4. Estimate the column diameter, based on flooding considerations.
5. Decide the liquid flow arrangement.
6. Make a trial plate layout: downcomer area, active area, hole area, hole size, weir height.
7. Check the weeping rate, if unsatisfactory return to step 6.
8. Check the plate pressure drop, if too high return to step 6.
9. Check downcomer back-up, if too high return to step 6 or 3.
10. Decide plate layout details: calming zones, unperforated areas. Check hole pitch, if unsatisfactory
return to step 6.
11. Recalculate the percentage flooding based on chosen column diameter.
12. Check entrainment, if too high return to step 4.
13. Finalize design.
| P a g e 21
Assumptions
Sieve plate
Weir height = 5 mm
Hole diameter = 50 mm
Plate thickness = 5 mm
Efficiency = 70%
Turn down = 70%
Equations
FLV
L

V
 v

 L



0.5
Where:
FLV = Liquid vapor flow rate.
L = Liquid flow rate.
V = Vapor flow rate.
 (   V ) 

U f  K 1  L
V


0.5
Where:
Uf = Flooding velocity.
K1 = Constant.
UV  Percentage Flooding x U f
Where:
Uv = Actual velocity.
| P a g e 22
MwtV
Vmax 
V
Where:
Vmax = Maximum volumetric flow rate.
MwtV = Vapor molecular weight.
Anet 
Vmax
UV
Anet = Net area required.
4

D   Anet 


0.5
Where:
D = Diameter.
max volumetric liquid rate 
LxMwt
L
Where:
L = Liquid flow rate.
AC 

4
D2
Where:
AC = Column area.
An  AC  Ad
Where:
An = Net area.
Aa  Ac  2 Ad
Aa= Active area.
| P a g e 23
Ah  0.1xAa
Ah= Hole area.
weir length  0.75D
2
 max liquid rate  3

max how  750
  L xweir length 
 min liquid rate 

min how  750

xweir
length
 L

2
3
Where:
how = Weir crest.
U h (min) 
K 2  0.9(25.4  hole diameter )
 0.5
Where:
Uh = Vapor velocity.
actual min . vapor velocity 
min . vapor rate
Ah
Where:
Ah = Hole area.
U
hd  51 h
 Co



2
 V

 L



Where:
hd = Pressure drop through dry plate.
Co = Orifice coefficient.
hr 
12.5 x10 3
L
Where:
hr= Residual head.
| P a g e 24
hap  hw  10
Where:
hap= Height of bottom edge of apron above plate.
hw= Weir height.
area under apron Aap  weir lengthxhap
 max . liquid rate 

hdc  166



xA
L
ap


2
hb  hw  hdc  ht  how
Where:
hb = back-up in downcomer.
tr 
hb xAdx L
Lwd
Where:
tr = Downcomer residence time.
Lwd = Minimum liquid flow rate.
UV 
volumetric flow rate
An
| P a g e 25
1.4 Heat Exchangers
What are heat exchangers?
Heat exchangers are devices used to transfer heat energy from one fluid to another. Typical heat
exchangers experienced by us in our daily lives include condensers and evaporators used in air
conditioning units and refrigerators. Boilers and condensers in thermal power plants are examples of
large industrial heat exchangers. There are heat exchangers in our automobiles in the form of radiators
and oil coolers. Heat exchangers are also abundant in chemical and process industries.
There is a wide variety of heat exchangers for diverse kinds of uses, hence the construction also would
differ widely. However, in spite of the variety, most heat exchangers can be classified into some
common types based on some fundamental design concepts. We will consider only the more common
types here for discussing some analysis and design methodologies.
Heat Transfer Considerations
The energy flow between hot and cold streams, with hot stream in the bigger diameter tube, is as shown
in Figure 1. Heat transfer mode is by convection on the inside as well as outside of the inner tube and
by conduction across the tube. Since the heat transfer occurs across the smaller tube, it is this internal
surface which controls the heat transfer process. By convention, it is the outer surface, termed Ao, of
this central tube which is referred to in describing heat exchanger area. Applying the principles of
thermal resistance,
End view of a tubular heat exchanger
If we define overall the heat transfer coefficient, Uc, as:
Substituting the value of the thermal resistance R yields:
| P a g e 26
Standard convective correlations are available in text books and handbooks for the convective
coefficients, ho and hi. The thermal conductivity, k, corresponds to that for the material of the internal
tube. To evaluate the thermal resistances, geometrical quantities (areas and radii) are determined from
the internal tube dimensions available.
Fouling
Material deposits on the surfaces of the heat exchanger tubes may add more thermal resistances to heat
transfer. Such deposits, which are detrimental to the heat exchange process, are known as fouling.
Fouling can be caused by a variety of reasons and may significantly affect heat exchanger performance.
With the addition of fouling resistance, the overall heat transfer coefficient, Uc, may be modified as:
where R” is the fouling resistance.
Fouling can be caused by the following sources:
1) Scaling is the most common form of fouling and is associated with inverse solubility salts. Examples
of such salts are CaCO3, CaSO4, Ca3(PO4)2, CaSiO3, Ca(OH)2, Mg(OH)2, MgSiO3, Na2SO4,
LiSO4, and Li2CO3.
2) Corrosion fouling is caused by chemical reaction of some fluid constituents with the heat exchanger
tube material.
3) Chemical reaction fouling involves chemical reactions in the process stream which results in
deposition of material on the heat exchanger tubes. This commonly occurs in food processing
industries.
4) Freezing fouling is occurs when a portion of the hot stream is cooled to near the freezing point for
one of its components. This commonly occurs in refineries where paraffin frequently solidifies from
petroleum products at various stages in the refining process. , obstructing both flow and heat transfer.
5) Biological fouling is common where untreated water from natural resources such as rivers and lakes
is used as a coolant. Biological micro-organisms such as algae or other microbes can grow inside the
heat exchanger and hinder heat transfer.
6) Particulate fouling results from the presence of microscale sized particles in solution. When such
particles accumulate on a heat exchanger surface they sometimes fuse and harden. Like scale these
deposits are difficult to remove.
With fouling, the expression for overall heat transfer coefficient becomes:
| P a g e 27
Basic Heat Exchanger Flow Arrangements
Two basic flow arrangements are as shown in Figure 2. Parallel and counter flow provide alternative
arrangements for certain specialized applications. In parallel flow both the hot and cold streams enter
the heat exchanger at the same end and travel to the opposite end in parallel streams. Energy is
transferred along the length from the hot to the cold fluid so the outlet temperatures asymptotically
approach each other. In a counter flow arrangement, the two streams enter at opposite ends of the heat
exchanger and flow in parallel but opposite directions. Temperatures within the two streams tend to
approach one another in a nearly linearly fashion resulting in a much more uniform heating pattern.
Shown below the heat exchangers are representations of the axial temperature profiles for each. Parallel
flow results in rapid initial rates of heat exchange near the entrance, but heat transfer rates rapidly
decrease as the temperatures of the two streams approach one another. This leads to higher energy loss
during heat exchange. Counter flow provides for relatively uniform temperature differences and,
consequently, lead toward relatively uniform heat rates throughout the length of the unit.
Basic Flow Arrangements for Tubular Heat Exchangers.
| P a g e 28
Log Mean Temperature Differences
Heat flows between the hot and cold streams due to the temperature difference across the tube acting as
a driving force. As seen in the Figure 7.3, the temperature difference will vary along the length of the
HX, and this must be taken into account in the analysis.
Temperature Differences Between Hot and Cold Process Streams
From the heat exchanger equations shown earlier, it can be shown that the integrated average
temperature difference for either parallel or counter flow may be written as:
The effective temperature difference calculated from this equation is known as the log mean
temperature difference, frequently abbreviated as LMTD, based on the type of mathematical average
that
it
describes.
While
the
equation
applies.
| P a g e 29
to either parallel or counter flow, it can be shown that ∆Ɵeff will always be greater in the
counter flow arrangement.
Another interesting observation from the above Figure is that counter flow is more
appropriate for maximum energy recovery. In a number of industrial applications there will be
considerable energy available within a hot waste stream which may be recovered before the
stream is discharged. This is done by recovering energy into a fresh cold stream. Note in the
Figures shown above that the hot stream may be cooled to t1 for counter flow, but may only
be cooled to t2 for parallel flow. Counter flow allows for a greater degree of energy recovery.
Similar arguments may be made to show the advantage of counter flow for energy recovery
from refrigerated cold streams.
Applications for Counter and Parallel Flows
We have seen two advantages for counter flow, (a) larger effective LMTD and (b) greater
potential energy recovery. The advantage of the larger LMTD, as seen from the heat
exchanger equation, is that a larger LMTD permits a smaller heat exchanger area, Ao, for a
given heat transfer, Q. This would normally be expected to result in smaller, less expensive
equipment for a given application.
Sometimes, however, parallel flows are desirable (a) where the high initial heating rate may
be used to advantage and (b) where it is required the temperatures developed at the tube walls
are moderate. In heating very viscous fluids, parallel flow provides for rapid initial heating
and consequent decrease in fluid viscosity and reduction in pumping requirement. In
applications where moderation of tube wall temperatures is required, parallel flow results in
cooler walls. This is especially beneficial in cases where the tubes are sensitive to fouling
effects which are aggravated by high temperature.
Multipass Flow Arrangements
In order to increase the surface area for convection relative to the fluid volume, it is common
to design for multiple tubes within a single heat exchanger. With multiple tubes it is possible
to arrange to flow so that one region will be in parallel and another portion in counter flow.
An arrangement where the tube side fluid passes through once in parallel and once in counter
flow is shown in the Figure 4. Normal terminology would refer to this arrangement as a 1-2
pass heat exchanger, indicating that the shell side fluid passes through the unit once, the tube
side twice. By convention the number of shell side passes is always listed first.
Multipass flow arrangement
| P a g e 30
The primary reason for using multipass designs is to increase the average tube side fluid
velocity in a given arrangement. In a two pass arrangement the fluid flows through only half
the tubes and any one point, so that the Reynold’s number is effectively doubled. Increasing
the Reynolds’s number results in increased turbulence, increased Nusselt numbers and,
finally, in increased convection coefficients. Even though the parallel portion of the flow
results in a lower effective ∆T, the increase in overall heat transfer coefficient will frequently
compensate so that the overall heat exchanger size will be smaller for a specific service. The
improvement achievable with multipass heat exchangers is substantialy large. Accordingly, it
is a more accepted practice in modern industries compared to conventional true parallel or
counter flow designs.
The LMTD formulas developed earlier are no longer adequate for multipass heat exchangers.
Normal practice is to calculate the LMTD for counter flow, LMTDcf, and to apply a
correction factor, FT, such that
The correction factors, FT, can be found theoretically and presented in analytical form. The
equation given below has been shown to be accurate for any arrangement having 2, 4,
6,.....,2n tube passes per shell pass to within 2%.
where the capacity ratio, R, is defined as:
The effectiveness may be given by the equation:
Provided that R>1. In the case that R=1, the effectiveness is given by:
| P a g e 31
Effectiveness-NTU Method:
Quite often, heat exchanger analysts are faced with the situation that only the inlet
temperatures are known and the heat transfer characteristics (UA value) are known, but the
outlet temperatures have to be calculated. Clearly, LMTH method will not be applicable here.
In this regard, an alternative method known as the ε-NTU method is used.
| P a g e 32
NTUmax can be obtained from figures in textbooks/handbooks
First, however, we must determine which fluid has Cmin.
Theory of Heat Exchanger:

Q  mC p T
Where:
- Qh = Heat load transfer in the hot side, KW.
- m  Mass flow rate in Kg/s.
- T  Temperature difference of the inlet and outlet.

Tlm 
(T1  t 2 )  (T2  t1 )
(T  t )
ln 1 2
(T2  t1 )
| P a g e 33
Where:
- TLM  Log means Temperature.
- T1  Inlet shell side fluid temperature (oC).
- T2  Outlet shell side fluid temperature (oC).
- t1  Inlet tube side temperature (oC).
- t 2  Outlet tube temperature (oC).

R
(T1  T2 )
(t 2  t1 )

S
(t 2  t1 )
(T1  t1 )

Tm  Ft Tlm
Where:
- Tm  True temperature difference.
- Ft  Temperature correction factor.
 A
Q
UTm
Where:
- A  Provisional area in m2.
- Q  Heat load in W.
| P a g e 34
- Tm  True temperature difference.

A  DL
Where:
- A  Area of one tube, m2.

N t  Provisional area/Area of one tube.
Where:
- N t  Number of tubes.
1

N
Db  d 0 ( t ) n1
K1
Where:
- Db  Bundle diameter (mm).
- d 0  Outside diameter (mm).
- N t  Number of tubes.
-K1 & n1 are constant.

Ds  Db  Clearance
Where:
- Ds  Sell diameter.
- Db  Bundle diameter (mm).

Ac 

4
(d i ) 2
Where:
- Ac  Tube cross-sectional area.
| P a g e 35
- di  Tube inner diameter.

Tubes N t

Pass
4
Where:
- N t  Number of tubes.

At  Ac
Tubes
Pass
Where:
- At  Total flow area.

Um 
m
At
Where:
- U m  Tube mass velocity.
- At  Total flow area.
- m  Mass flow rate in Kg/s.

Ut 
Um
 ref
Where:
- U t  Tube linear velocity.
-  ref  Density.
(4200 * (1.35  0.02t ) * U t )
0.8

hi 
di
0.2
Where:
- hi  Inside coefficient (W/m2 oC).
- U t  Tube linear velocity.
| P a g e 36
- t  Mean temperature (oC).

Re 
U t d i

Where:
- Re  Reynolds number.
-   Fluid viscosity at the bulk fluid temperature, Ns/m2.

Pr 
Cp
kf
Where:
- Pr  Prandtl number.
- C p  Heat capacity.
- k f  Thermal conductivity of stream.

hi 
k f j h Re(Pr) 0.33
di
Where:
- hi  Inside coefficient (W/m2 oC).
- j h  Tube side heat transfer factor.
- k f  Thermal conductivity of stream.
- Pr  Prandtl number.

lB 
Ds
5
Where:
- l B  Baffle spacing.
- Ds  Shell diameter.
| P a g e 37

pt  1.25d 0
Where:
- pt  Tube pitch.
- d 0  Outside diameter (mm).

As 
( p t  d 0 ) Ds l B
pt
Where:
- As  Cross-flow area.
- pt  Tube pitch.
- d 0  Outside diameter (mm).

Gs 
- Ds  Shell diameter.
m
As
Where:
- Gs  Mass velocity.
- As  Cross-flow area.
- m  Mass flow rate in Kg/s.

de 
1.1 2
2
( pt  0.917 d 0 )
d0
Where:
- d e  Equivalent diameter (mm).
- d 0  Outside diameter (mm).
- pt  Tube pitch.
| P a g e 38

Re 
Gs d e

Where:
- Re  Reynolds number.
- d e  Equivalent diameter (mm).
- Gs  Mass velocity.
-   Fluid viscosity at the bulk fluid temperature, Ns/m2.

1
1
1



U 0 h0 hod
d 0 ln(
d0
)
di
2k w

d0 1 d0 1

d i hid d i hi
Where:
- U 0  The overall heat transfer coefficient.
- hod  Outside coefficient (fouling factor).
- hid  Inside coefficient (fouling factor).

 L
Pt  N p 8 j f 
  d i
  



 w 
m
 u 2
 2.5 t
 2
Where:
- Pt  Tube- side pressure drop (N/m²) (pa).
- N p  Number of tube -side passes.
- u t  Tube-side velocity, m/s.
- L  Length of one tube.
| P a g e 39
- j f  Friction factor.
-  w  Fluid viscosity at the wall.
-   Fluid viscosity at the bulk fluid temperature, Ns/m2.

D
Ps  8 j f  s
 de
 L

 l B
 u s 2

 2
 

 w



0.14
Where:
- Ps  Shell-side pressure drop (N/m²) (pa).
- j f  Friction factor.
- L  Length of tube.

t
Pri
 Cc
SEj  0.6 P
Where:
- t  Shell thickness (in).
- P  Maximum allowable internal pressure (psig).
- ri  Internal radius of shell before allowance corrosion is added (in).
- E j  Efficiency of joints.
- S  Working stress (psi).
- C c  Allowance for corrosion (in)
| P a g e 40
1.5. Flash Separator (V-L Separator)
A vapor–liquid separator is a device used in several industrial applications to separate
a vapor–liquid mixture. For the common variety, gravity is utilized in a vertical vessel to
cause the liquid to settle to the bottom of the vessel, where it is withdrawn. In low gravity
environments such as a space station, a common liquid separator will not function because
gravity is not usable as a separation mechanism. In this case, centrifugal force needs to be
utilized in a spinning centrifugal separator to drive liquid towards the outer edge of the
chamber for removal. Gaseous components migrate towards the center. The gas outlet may
itself be surrounding by a spinning mesh screen or grating, so that any liquid that does
approach the outlet strikes the grating, is accelerated, and thrown away from the outlet. In our
process vertical flash separator is used.
Vertical Separation
| P a g e 41
Theory used in flash separator calculation
Ut  0.07(
l  v 0.5
)
v
Where:
Ut : Settling velocity (m/s)
ρL : density of liquid
ρV : density of vapor
Us  Ut * 0.15
Where:
Us : settling velocity (corrected velocity because of existent of demister) (m/s)
Ut : settling velocity (m/s)
VHV= LV*T*60
Where:
VHV : Volume held up= Vl*time (m/s)
LV : liquid volumetric flow rate (m3/s)
DV  (
4 * VV
) 0.5
3.14 * U S
Where:
Dv : minimu vessel diameter (m)
VV : volumetric vapor flow rate (m3/s)
HV 
VHV
3.14 * DV 2
(
)
4
| P a g e 42
Where:
Hv : liquid depth required (m)
TH 
p * RI
 Cc
S * EJ  0.6 * P
Where:
TH : thickness (in)
P : internal pressure (psig)
RI : internal radius of shell (in)
Ej : efficiency of joints
S : working stress (psi) =13700 for Carbon Steel
Cc : allowance for corrosion (in)
H 
DV
 0.4  DV  HV
2
Where:
Dv : minimum vessel diameter (m)
Hv= liquid depth required (m)
H : height of vessel (m)
Ac 
2Dv 2
 DvH
4
Ac : area of vessel (m2)
Dv :
vessel diameter (m)
H : height of vessel (m)
| P a g e 43
Volume of metal = area of the vessel * thickness
Weight of metal
Wm  Vm * 
Where:
Wm= weight of metal
Vm= volume of metal (m3)
ρ= density of steel (kg/m3)
| P a g e 44
1.6. Compressor K-101
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its
volume. Compressors are similar to pumps: both increase the pressure on a fluid and both can
transport the fluid through a pipe. As gases are compressible, the compressor also reduces the
volume of a gas. Liquids are relatively incompressible; while some can be compressed, the
main action of a pump is to pressurize and transport liquids.
Types of compressors
The main types of gas compressors are illustrated and discussed below
Centrifugal compressors
Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to
the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section
converts the velocity energy to pressure energy. They are primarily used for continuous,
stationary service in industries such as oil refineries, chemical and petrochemical plants and
natural gas processing plants. Their application can be from 100 horsepower (75 kW) to
thousands of horsepower. With multiple staging, they can achieve extremely high output
pressures greater than 10,000 psi (69 MPa)
Axial-flow compressors
Axial-flow compressors are dynamic rotating compressors that use arrays of fan-like airfoils
to progressively compress the working fluid. They are used where there is a requirement for a
high flow rate or a compact design.The arrays of airfoils are set in rows, usually as pairs: one
rotating and one stationary. The rotating airfoils, also known as blades or rotors, accelerate
the fluid. The stationary airfoils, also known as stators or vanes, decelerate and redirect the
flow direction of the fluid, preparing it for the rotor blades of the next stage. Axial
compressors are almost always multi-staged, with the cross-sectional area of the gas passage
diminishing along the compressor to maintain an optimum axial Mach number. Beyond about
5 stages or a 4:1 design pressure ratio, variable geometry is normally used to improve
operation.Axial compressors can have high efficiencies; around 90% polytropic at their
| P a g e 45
design conditions. However, they are relatively expensive, requiring a large number of
components, tight tolerances and high quality materials. Axial-flow compressors can be found
in medium to large gas turbine engines, in natural gas pumping stations, and within certain
chemical plants.
Reciprocating compressors
Reciprocating compressors use pistons driven by a crankshaft. They can be either stationary
or portable, can be single or multi-staged, and can be driven by electric motors or internal
combustion engines. Small reciprocating compressors from 5 to 30 horsepower (hp) are
commonly seen in automotive applications and are typically for intermittent duty. Larger
reciprocating compressors well over 1,000 hp (750 kW) are commonly found in large
industrial and petroleum applications. Discharge pressures can range from low pressure to
very high pressure (>18000 psi or 180 MPa). In certain applications, such as air compression,
multi-stage double-acting compressors are said to be the most efficient compressors available,
and are typically larger, and more costly than comparable rotary units. Another type of
reciprocating compressor is the swash plate compressor, which uses pistons which are moved
by a swash plate mounted on a shaft - see Axial Piston Pump. Household, home workshop,
and smaller job site compressors are typically reciprocating compressors 1½ hp or less with
an attached receiver tank.
Rotary compressors
There are many types of rotary compressor one of them is the rotary screw compressors. The
rotary screw compressors use two meshed rotating positive-displacement helical screws to force the
gas into a smaller space. These are usually used for continuous operation in commercial and industrial
applications and may be either stationary or portable. Their application can be from 3 horsepower
(2.2 kW) to over 1,200 horsepower (890 kW) and from low pressure to moderately high pressure
(>1,200 psi or 8.3 MPa).Rotary screw compressors are commercially produced in Oil Flooded, Water
Flooded and Dry type.
Another type of rotary compressor is rotary vane compressor. Rotary vane compressors
consist of a rotor with a number of blades inserted in radial slots in the rotor. The rotor is
mounted offset in a larger housing which can be circular or a more complex shape. As the
rotor turns, blades slide in and out of the slots keeping contact with the outer wall of the
housing. Thus, a series of decreasing volumes is created by the rotating blades. Rotary Vane
compressors are, with piston compressors one of the oldest of compressor technologies. With
suitable port connections, the devices may be either a compressor or a vacuum pump. They
can be either stationary or portable, can be single or multi-staged, and can be driven by
electric motors or internal combustion engines. Dry vane machines are used at relatively low
pressures (e.g., 2 bar or 200 kPa; 29 psi) for bulk material movement while oil-injected
machines have the necessary volumetric efficiency to achieve pressures up to about 13 bar
(1,300 kPa; 190 psi) in a single stage. A rotary vane compressor is well suited to electric
motor drive and is significantly quieter in operation than the equivalent piston compressor.
Rotary vane compressors can have mechanical efficiencies of about 90%
| P a g e 46
Theory used in Compressor calculation
 n 


P1  T1  n 1 
 
P2  T 2 
Where
P1 : inlet pressure, psia
P2 : outlet pressure, psia
T1 : inlet temperature, R
T2 : outlet temperature, R
n : compression factor
nR (T1 T 2 )
1 n
W 
Where
W : work done, Btu/lbmol
R : Cp/Cv
Hp=W*M
Where
Hp : horse power, Hp
M : molar flow rate, lbmol/s
Ep 
n
n 1
K
K 1
Where
Ep : efficiency of the compressor
K 
MwC p
MwC p  1.986
Where Cp: heat capacity, Btu/lb F0
Mw: molecular weight of the gas
| P a g e 47
1.7. Pumps
Pump is a machine or device used for moving an incompressible liquid from lower to higher
pressure and overcoming this difference by adding energy to the system.
There are two main categories of pumps - kinetic and positive displacement. Almost all
pumps fall into one of these two categories. The main difference between kinetic and positive
displacement pumps lies in the method of fluid transfer. A kinetic pump imparts velocity
energy to the fluid, which is converted to pressure energy upon exiting the pump casing. A
positive displacement pump moves a fixed volume of fluid within the pump casing by
applying a force to moveable boundaries containing the fluid volume.
Kinetic pumps can be further divided into two categories of pumps – centrifugal and
special effect. Special effect pumps include jet pumps, reversible centrifugal, gas lift,
electromagnetic and hydraulic ram. Special effect pumps are not commonly used relative to
centrifugal pumps, so they will not be covered in this course.
Positive displacement pumps are also divided into two major pump categories –
reciprocating and rotary. Reciprocating pumps transfer a volume of fluid by a crankshaft,
eccentric cam or an alternating fluid pressure acting on a piston, plunger or a diaphragm in a
reciprocating motion. Rotary pumps operate by transferring a volume of fluid in cavities
located between rotating and stationary components inside the pump casing. The relative
features of reciprocating and rotary pumps, as well as centrifugal pumps, will be covered in
this course.
Figure 7-1 below shows the major pump categories and the types of pumps within each
category.
| P a g e 48
Figure 7-1 – Major Pump Categories
Comparison Table – Centrifugal vs. Positive Displacement Pumps
Table 3-1 below outlines some of the main differences between centrifugal pumps,
reciprocating pumps and rotary pumps. Note that “centrifugal”, “reciprocating” and “rotary”
pumps are all relatively broad categories. The table below provides a comparison of features
between these pump categories that generally holds true. However, there are exceptions. For
example, reciprocating pumps generally require more space than centrifugal pumps for a
given flow rate. But, there may be specific applications where a positive displacement pump
| P a g e 49
requires less space relative to a centrifugal pump. Also, note that Table 7-1 lists typical
maximum flow rates and heads. It is possible to build special pumps outside the upper
bounds of the pressures and flow rates listed, but such pumps would be prohibitively
expensive for most applications.
Table 7-1 – Pumps comparison Table
Parameter
Centrifugal Pumps
Optimum
Flow Medium/High
and
Pressure Capacity,
Applications
Low/Medium
Pressure
Maximum
Flow 100,000+ GPM
Rate
Low Flow Rate
No
Capability
Maximum
6,000+ PSI
Pressure
Requires
Relief No
Valve
Smooth or
Smooth
Pulsating Flow
Variable or
Variable
Constant Flow
Self-priming
No
Space
Requires Less Space
Considerations
Costs
Lower Initial
Lower Maintenance
Higher Power
Fluid Handling
Reciprocating
Pumps
Rotary Pumps
Low Capacity,
High Pressure
10,000+ GPM
Low/Medium
Capacity,
Low/Medium
Pressure
10,000+ GPM
Yes
Yes
100,000+ PSI
4,000+ PSI
Yes
Yes
Pulsating
Smooth
Constant
Constant
Yes
Requires
More
Space
Higher Initial
Higher
Maintenance
Lower Power
-Suitable for a wide
-Suitable for clean,
range including clean, clear, non-abrasive
clear, non-abrasive
fluids. Speciallyfluids to fluids with
fitted pumps
abrasive, high-solid
suitable for
content.
abrasive-slurry
-Not suitable for high service.
viscosity fluids
-Suitable for high
-Lower tolerance for
viscosity fluids
entrained gases
-Higher tolerance
for entrained gases
Yes
Requires
Less
Space
Lower Initial
Lower Maintenance
Lower Power
-Requires clean,
clear, non-abrasive
fluid due to close
tolerances
-Optimum
performance with
high viscosity
fluids
-Higher tolerance
for entrained gases
| P a g e 50
Capacity
The wide variety of centrifugal pumps manufactured offer a relatively large range of
available capacities. Radial-flow and mixed flow pumps are used for low to medium capacity
applications. For high capacity applications, axial-flow pumps are capable of delivering flow
rates in excess of 100,000 gpm. Centrifugal pumps are not stable at low flow rates, although
there are special low-flow centrifugal pumps available that can deliver flow rates less than 10
gpm. However, for extreme low-flow applications (< 1 gpm), positive displacement pumps
are a better selection.
Reciprocating and rotary pumps are capable of capacities ranging from low to
medium, with flow rates peaking at 10,000+ gpm. In theory, reciprocating pumps can be
manufactured to deliver more capacity, but they become prohibitively large and expensive at
high flow rates. Both reciprocating and rotary pumps are capable of delivering product at
extremely low flow rates (fractions of a gpm), making them particularly suitable for many
chemical injection applications.
Pressure
Centrifugal pumps and rotary pumps are best suited for low to medium pressure
applications. Reciprocating pumps are usually specified for high pressure service, with
capabilities exceeding 100,000 psi. Multi-stage centrifugal pumps can deliver at pressures of
6,000+ psi and may be the most economical choice at this pressure in high capacity
applications. But, in most applications exceeding 1,000 psig, reciprocating pumps are more
suitable, particularly in low to medium capacity service. Both reciprocating and rotary pumps
will continually increase pressure when pumping against a closed discharge to the extent
allowed by the driver’s horsepower. This can result in overpressure of the pump or piping
components, so it is necessary to install a relief valve on the discharge of the pump capable of
discharging the full capacity of the pump. A centrifugal pump’s pressure rise is limited to the
shut-off pressure on the pump curve, which is always less than the design pressure of the
pump (and the piping system if properly designed). A relief valve is only needed if no other
measures are provided to detect low flow conditions and shut down the pump to prevent
damage. The relief valve need only be sized to pass the minimum flow rate required to
maintain stable flow and prevent excessive temperature rise.
Smooth or Pulsating Flow
| P a g e 51
Centrifugal pumps and most rotary pumps provide smooth, non-pulsating flow, while
reciprocating pumps produce a pulsating flow. A pulsating flow may require special design
considerations in the piping system. If the pump is not located near the suction source, then
acceleration head can contribute to low NPSHA problems, which may require the installation
of a suction stabilizer. A pulsation dampener may need to be installed in the discharge piping
to reduce pressure surges resulting from the pulsating flow.
Variable or Constant Flow
Centrifugal pumps operate on a variable-flow, variable-head curve. As the discharge
pressure decreases, the pump delivers a higher flow rate. At any given speed, reciprocating
and rotary pumps operate at a constant flow rate regardless of the discharge pressure. There
are specific applications that require either constant flow or variable flow. Metering pumps
rely on a constant flow at varying pressures, which makes reciprocating pumps and rotary
pumps suitable for this application. Piston pumps used for metering will often use an
adjustable stroke length to allow the operator to vary the flow rate to meet the system
requirements. Centrifugal pumps are favored where process conditions often require varying
flow rates. For example, a level control valve must throttle the flow rate from a vessel to
maintain a constant level in the vessel. A centrifugal pump is well suited to handle this
process condition, whereas a positive displacement pump would either require a continuous
recycle to suction or a variable speed driver to accommodate the variable flow.
Self-priming
Reciprocating and rotary pumps are self-priming. This is an important consideration
where a prime cannot be maintained on the pump. Centrifugal pumps are not inherently selfpriming, although some manufacturers do specially design self-priming units. External
priming sources, such as an eductor or vacuum pump can also be employed.
Costs and Space Considerations
In an overlap region where the conditions are suitable to use a centrifugal,
reciprocating or a rotary pump, the following rules generally apply: The reciprocating pump
will generally have higher initial capital costs and will require more space relative to the
| P a g e 52
centrifugal pump or the rotary pump. The reciprocating pump will generally have higher
maintenance costs relative to the centrifugal pump or the rotary pump. The centrifugal pump
will generally have higher annual power consumption costs relative to the reciprocating pump
or the rotary pump because of lower efficiencies. Of course, there are many exceptions.These
are just general guidelines.
A pump that is selected for an application outside of its optimum operating parameters
will almost certainly not follow these rules.For example, a rotary pump operating in a high
pressure, abrasive-slurry service would probably have higher maintenance costs than a
properly selected reciprocating pump. The close running clearances (particularly for high
pressure service) required in the rotary pump would likely result in premature wear and
frequent maintenance.
Fluid Handling
Centrifugal pumps are suitable for transferring a variety of fluids ranging from clean,
clear non-abrasive fluids to abrasive-slurries. However, a centrifugal pump is not the best
choice for pumping highly viscous fluids due to dramatic drops in efficiency at high
viscosities. Centrifugal pumps are not normally specified for viscosities higher than about
4,000 SSU. Centrifugal pumps are also not well suited to pumping entrained air. Most
centrifugal pumps can handle up to about 2% entrained gas and specially-designed pumps can
handle up to about 10%.
Reciprocating pumps are well suited for transferring clear, non-abrasive fluids, as well
as abrasive slurries. In fact, the relatively low velocities of moving parts within a
reciprocating pump make it particularly resistant to erosion in abrasive-slurry applications,
provided that the pump is properly designed for the
service. Reciprocating pumps maintain high efficiencies when pumping highly viscous fluids
and can easily handle 50% and higher volumes of entrained gas.
Rotary pumps can also handle high viscosity fluids and high volumes of entrained gas In fact,
many rotary pumps operate at their best efficiency at higher viscosities. However, rotary
pumps are not well suited for pumping corrosive fluids or fluids with abrasive solids because
of close clearances between rotating and static pump components.
| P a g e 53
Table 7-2 Nomenclatures of pump
Symbol
Definition
BHP
Break horsepower of the pump
WHP
Actual horse power
V̇
Volumetric flow rate
ha
The static head of the pump
Ρ
The density of the fluid
∆P
The pressure difference between the inlet and outlet
streams i
𝑚̇
Mass flow rate
𝛾
The specific weight
For designing pump it should follow this procedure:
1- At the first it should be know enough data such as:
- Mass Flow rate (𝑚̇)
- Density (ρ)
- Pressure difference (ΔP)
- Gravity (G)
2- Calculate the volumetric flow rate:
𝑉̇ =
𝑚̇
ρ
3- Calculate the specific weight:
𝛾=ρ*G
4- Calculate the head:
ha=
ΔP
𝛾
5- Calculate the actual horse power 𝑊𝐻𝑃: WHP =
𝛾 𝑉̇ ℎ𝑎
746
6- Calculate the maximum and minimum break horse power 𝐵𝐻𝑃: η =
𝑊𝐻𝑃
𝐵𝐻𝑃
| P a g e 54
1.8. Valves
A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids,
fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.
Valves are technically pipe fittings, but are usually discussed as a separate category. In an
open valve, fluid flows in a direction from higher pressure to lower pressure.
Valves are used in a variety of contexts, including industrial, military, commercial,
residential, and transport. The industries in which the majority of valves are used are oil and
gas, power generation, mining, water reticulation, sewage and chemical manufacturing.
In nature, veins acting as valves are controlling the blood circulation; heart valves control the
flow of blood in the chambers of the heart and maintain the correct pumping action.
Valves play a vital role in industrial applications ranging from transportation of drinking
water to control of ignition in a rocket engine.
Valves may be operated manually, either by a handle, lever or pedal. Valves may also be
automatic, driven by changes in pressure, temperature, or flow. These changes may act upon
a diaphragm or apiston which in turn activates the valve, examples of this type of valve found
commonly are safety valves fitted to hot water systems or boilers.
Valve control
Control valves are imperative elements in any system where fluid flow must be monitored and
manipulated. Selection of the proper valve involves a thorough knowledge of the process for which it
will be used. Involved in selecting the proper valve is not only which type of valve to use, but the
material of which it is made and the size it must be to perform its designated task.
The basic valve is used to permit or restrain the flow of fluid and/or adjust the pressure in a system. A
complete control valve is made of the valve itself, an actuator, and, if necessary, a valve control
device. The actuator is what provides the required force to cause the closing part of the valve to move.
Valve control devices keep the valves in the proper operating conditions; they can ensure appropriate
position, interpret signals, and manipulate responses.
When implementing a valve into a process, one must consider the possible adverse occurrences in the
system. This can include noise due to the movement of the valve, which can ultimately produce shock
waves and damage the construction of the system. Cavitation and flashing, which involve the rapid
expansion and collapse of vapor bubbles inside the pipe, can also damage the system and may corrode
the valve material and reduce the fluid flow.
No matter which avenue you take, the following criteria should be considered to assure you
select the right valve, the first time:
| P a g e 55
• Process Parameters:
• Flow
• Pressure
• Temperature
• Chemical Compatibility:
• Media
• Concentration
• % of Solids
• Specific Gravity (sg)
• Process Requirements:
• On/Off versus control service
• Allowable leakage rate
• Cleanliness
• Emissions Control
• Available space and structural considerations
There are many types of valves like :
Globe Valves
A globe valve is a type of valve used for regulating flow in a pipeline, consisting of a movable
disk-type element and a stationary ring seat in a generally spherical body. The valve can have
a stem or a cage. The fluid's flow characteristics can be controlled by the design of the plug
being used in the valve. A seal is used to stop leakage through the valve. Globe valves are
designed to be easily maintained. They usually have a top that can be easily removed,
exposing the plug and seal. Globe valves are good for on, off, and accurate throttling purposes
but especially for situations when noise and caviatation are factors. A common example
would be the valves that control the hot and cold water for a kitchen or bathroom sink.
| P a g e 56
Butterfly Valves
Butterfly valves consist of a disc attached to a shaft with bearings used to facilitate rotation. The
characteristics of the flow can be controlled by changing the design of the disk being use. Butterfly
valves are good for situations with straight flow and where a small pressure drop is desired. There are
also high performance butterfly valves.
Ball Valves
A ball valve is a valve with a spherical disc, the part of the valve which controls the flow through it.
The sphere has a hole, or port, through the middle so that when the port is in line with both ends of the
valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and
flow is blocked.
Ball valves are good for on/off situations. A common use for a ball valve is the emergency shut off for
a sink.
| P a g e 57
The Gate Valve
This is the most common type of valve in use in industry and is used to start or stop the flow
of fluids. It gives a positive shut-off when closed and is often used as a 'Block Valve' for
isolating systems.
The gate valve MUST be either FULLY CLOSED or FULLY OPEN and NEVER USED TO
CONTROL FLOW, as the fluid velocity will erode the valve internals - gate and body seats.
A gate valve may be of the 'RISING STEM' type or a 'NON-RISING STEM', in which the
stem threads are 'Left-hand' threads set into the gate itself.
| P a g e 58
2. Equipment Calculation
2.1. Abdullah’s Design
2.1.1. Reactor (CRV-100)
Assumption

The porosity of the catalyst Φ=0.2

the ratio of length to diameter (L/D)=4
Kinetic Data
From NIST kinetics Database
A = 0.54 kmol/kgcat.hr.kPa^2
Ea = 52.36 kJ/mol
R = 0.008314 kJ/mol.K
T = 603 K
(from HYSYS)
k = 0.54 * e(-52.36/0.008314*603) = 1.6 E-05 kmol/kgcat.hr.kPa^2
Catalyst weight
y A0 = 0.66
(from HYSYS)
 = 1+1 -1 = 1
  y A0  0.66 * (1  1  1)  0.66
| P a g e 59
From HYSYS
FA0 =
164.8 Kmol/hr
T0 =
603
K
T
603
K
=
P0 =
111.3 kPa
P =
111.3 kPa
X =
0.56
PA0 = yA0 * P0 = 0.66* 111.3 = 73.46 kPa
r
dx
 A
dW FA0
 r  k ( P )^ 2
A
A
1  x  T0  P 
P P
A
A0 1  x  T  P 
  0 
By using Polymath program
W  3613 kg.cat
Reactor Volume
 ( Bulk )  1200 kg / m 3
From Matros Technologies
W
1192.63
V (reactor ) 

 3.76 m 3
(1   ) *  (1  0.2) *1200
V 

4
D2L 
V 
D 
 
1/ 3

4
D 2 (4 D)  D 3
 3.76 


  
Where L/D=4
1/ 3
 1.06 m
H= L  4D  4 * 0.845  4.25 m
A
V 1.89

 0.886 m 2
H 3.38
| P a g e 60
Calculate the Area of Heat Exchanger needed to make the reactor isothermal
Tlm 
(T1  t 2 )  (T2  t1 ) (330  350)  (330  500)

 70.77C
(T1  t 2 )
(330  350)
ln
ln
(330  500)
(T2  t1 )
Tm  Ft Tlm  0.98 * 70.77  69.35C
A
Q
1952

 243 m2
UTm 120 * 69.35
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
Assume 4 Tube Pass
do
mm
30
di
mm
27
flow rate
kg/s
6.255
density
kg/m3
L
m
2.46
Ao=
m2
234.5
Area of one tube
m2
0.232
# of tubes
0.31814
1011.58
| P a g e 61
Thickness calculation
ri 
Ds
1.06
* 39.3701 
* 39.3701  20.9 in
2
2
P = 1.4467 psig
(From HYSYS)
S = 13706.66 psi
Ej = 0.85
Cc = 0.125 in
t
Pri
1.4467 * 20.9
 0.125
 Cc 
13706.66 * 0.85  0.6 * 14.696
SEj  0.6 P
 0.128in  3.2mm
(Take it 10 mm)
Cost calculation
Reactor volume = 994.3 gallon with carbon steel as material of construction.
Cost of the reactor =$38200
(from www.matche.com)
| P a g e 62
Equipment Name
Reactor
Objective
To convert Ethanol to Acetaldehyde
Equipment Number
CRV-100
Designer
Abdullah Al-Shemali
Type
PBR
Location
after cooler E-100
Material of Construction
Carbon Steel
Insulation
Fiber Glass
Operating Condition
Operating Temperature (oC)
329.9
Volume of Reactor (m3)
Operating Pressure (psia)
16.134
Catalyst Type
Feed Flow Rate (mole/s)
74.92
Catalyst Density (Kg/m3)
1200
Conversion (%)
56%
Catalyst Diameter (mm)
19
Weight of Catalyst (Kg)
3613
Reactor Height (m)
4.25
3.76
Ni -alumina
Number of Beds
-
Reactor Diameter (m)
1.06
Height of Bed/s (m)
-
Reactor Thickness (mm)
10
Cost ($)
$ 58000
| P a g e 63
2.1.2. Flash separator
From HYSYS
ρv=
ρl=
Vv=
L=
1.764
818.136
424.197
11
Kg/m3
Kg/m3
m3/hr
m3/hr
=0.1178325 m3/s
=3.06E-03 m3/s
Settling velocity:
l  v 0.5
818.136  1.764 0.5
)  0.07(
)  1.5 m/s
v
1.764
Ut  0.07(
Us  Ut * 0.15  1.5 * 0.15  0.226 m/s
Volume Held in Vessel (VHV):
Allow a minimum of 5 minuts hold up (T= 5 min)
VHV  LV * T * 60  0.00306 * 5 * 60  0.917m 3
Vessel diametar (Dv):
4 * VV
4 * 0.1178 0.5
) 0.5  (
)
 0.815m
3.14 * U S
3.14 * 0.226
DV  (
Liquid Depth (HV):
VHV
HV 
2
(3.14 *
DV
)
4

0.917
 1.76m
0.815
3.14 *
4
Length
DV
 0.4  DV  HV
2
0.815
H 
 0.4  0.815  1.76  3.38m
2
H 
Thickness:
Ri 
DV
0.815
* 39.37021 
* 39.37021  16.05in
2
2
TH 
p * RI
86.83 * 216.05
 Cc 
 0.125  0.2452in  0.00622m
S * EJ  0.6 * P
13700 * 0.85  0.86 * 86.83
| P a g e 64
Surface area of the vessel
Ac 
2Dv 2
2 (0.815) 2
 DvH 
  * 0.815 * 3.38 =9.69 m2
4
4
Volume of Metal = area of the vessel * thickness = 9.69*0.006278= 0.06038 m3
Weight of metal:
Wm = Vm * ρ= 0.06038*7900 =1051.3 (lb)
Cost of the Flash Tank = $ 15400
(from www.matche.com)
Equipment Name
Flash Tank (V-L Separator )
Objective
To separate liquid from vapor
Equipment Number
V-101
Designer
Abdullah Al-Shemali
Type
Vertical
Location
after cooler E-102
Material of Construction
Carbon steel
Insulation
Polystyrene
Cost ($)
$ 15400
Operating Condition
Operating Temperature (oC)
42.05
Operating Pressure (psig)
86.83
Gas Density (kg/m3)
1.7642
Design Considerations
Liquid Density (kg/m3)
818.136
Viscosity (cp)
0.424
Z factor
Gas Flow rate (barrel/day)
64035
Liquid Flow rate (barrel/day)
0.815
Height (m)
1
1661.2
Dimensions
Diameter (m)
3.38
| P a g e 65
2.1.3. Compressor
From HSYSYS
Molar flow rate =
0.2073 (lbmol/s)
P1
=
16.14 (psia)
P2
=
103 (psia)
T1
=
766.8 (R)
T2
=
1076 (R)
Mw
=
26.784
Z1
=
1
R (Cp/Cv)
=
1.1846
Cp
=
0.4759 (Btu/lb˚F)
P1  T1 
 
P2  T 2 
 n 


 n 1 
Using solver n = 1.22
nR (T1 T 2 )
= 1.22*1.184*(766.8-1076)/(1-1.22) = 2003.87 Btu/lbmol
1 n
W 
Hp=W*M =( 2003.87*0.20734*0.001341)/0.0009486 = 587.256 hp
K 
MwC p
MwC p  1.986
Ep 
= 26.78*0.475/(26.78*0.475-1.986) = 1.1845
n
n  1 = (1.22/0.22)/(1.1845/0.845)=85.25 %
K
K 1
| P a g e 66
Cost Calculation
Flow rate of inlet stream =11651 m3/h & discharge pressure= 5.987 bar using
the below figure our compressor is Centrifugal compressor. Material of
construction is carbon steel.
Cost of the compressor = $ 421900
(from www.matche.com)
Compressor operating ranges
| P a g e 67
Equipment Name
Compressor
Objective
To increase the Pressure
Equipment Number
K-101
Designer
Abdullah Al-Shemali
Type
Centrifugal
Location
after heater E-101
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
Cost
$ 421900
Operating Condition
Inlet Temperature (oC)
152.9
Outlet Temperature (oC)
326.1
Inlet Pressure (psia)
16.14
Outlet Pressure (psia)
103
Efficiency (%)
85.25%
Power (Hp)
587.36
| P a g e 68
2.1.4. Heat Exchanger (Cooler E-101)
Parameter
Unit
Value
Duty
kW
974.518
Prameter
Unit
Inlet
Tempreture Ti
C
Thermal Conductivty k
Water Stream (tube Side):
Outlet
Mean
25
94.65
59.825
W/m.C
0.611
0.678
0.148
Mass Density ρ
kg/m3
1007.3
952.36
979.83
Viscosity μ
mPa.s
0.89044
0.2955
0.5929
Specfic Heat Cp
KJ/Kg.
K
4.202
4.1937
4.198
Mass Flow Rate
kg/s
3.33
Process Steam (shell Side):
Prameter
Unit
Inlet
Outlet
Mean
Temperture ti
C
329.9
152.9
241.4
Thermal Conductvity
W/m.C
0,0768
0.05299
0,0648
Mass Density
kg/m3
0.735
0.702
0.7185
Viscosity
mPa.s
0.01957
0.01329
0.0164
Specfic Heat Cp
KJ/Kg.
K
2.3727
1.9918
2.18225
Mass Flow Rate
kg/s
2.523
| P a g e 69
Overall Heat Transfer Coefficients:
From table 12.1 :
27
Assume Uo=
Tlm 
R
W/m2.C
T1  t2   T2  t1 
 T  t  
ln  1 2 
 T2  t1  
T1  T2  ; S  t 2  t1 
t 2  t1
T1  t1
Tm  Ft Tlm
∆Tlm = 176.16 C
R = 2.54
S = 0.228
From Figure 12.19
Ft = 0.98
∆Tm = 0.98 * 176.16= 172.633 C
Heat Transfer Area
Q =U A ∆Tm
U = 27 W/m2 °C
∆Tm = 172.633 C
Q = 974.52 * 1000 = 974520W
| P a g e 70
Heat transfer area:
A = 209.07 m2
Layout and Tube Size
From Table 12.3
Assume Outler diameter (do)
20
mm
Assume inside diameter (di)
16
mm
Assume Length of tubes (L)
4.5
m
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
Assume 4 Tube Pass
do
mm
20
di
mm
16
flow rate
kg/s
3.3
density
kg/m3
979.83
L
m
4.5
Ao=
m2
209.07
Area of one tube
m2
0.283
# of tubes
739
| P a g e 71
Bundle and Shell Diameter
1
 N  n1
Db  d o  t  ; K1 , n1  f No.Passes 
 K1 
Ds  Db  Re ading Fig .12.10
From table 12.4
K1 = 0.175
n1 = 2.285
From Figure 12.10:
Db = 0.7724m
Reading = 66 mm
So the value of Ds = 838mm
Tube side Heat Transfer Cofficient
Re 
cp
ut d i
; Pr 

k
Nu  jh Re Pr
 kf
hi  Nu
 di
0.33
 
  
w

0.14
; jh  f (
L
)
di



Reynolds Number:
Re = 2420
Prandtl Number:
Pr = 3.86
| P a g e 72
I/Di = 281.25
From Figure 12.23, heat transfer factor (jh) is:
Jh = 2.35 E-04
Inside Coefficient (hi):
hi = 36 W/m2 C
Shell side heat transfer Coefficient:
As 
 pt  d o Ds lB
pt
us 
FlowRate
As 
de 
1. 1 2
2
pt  0.917 d o
do
Re 
cp
u s d e
; Pr 

k


Nu  jh Re Pr 0.33   
 w 
 kf 
hs  Nu 
 de 
0.14
; jh  f Re, buffle _ cut 
Take baffle spacing = 0.2*Ds
Triangular Pitch = 31.25mm
do = 20mm
Ds =838 mm
Ib = Baffle spacing * Ds = 167.68 mm
As = 0.0281 m2
de = 14.2mm
us = 0.52 m/s
Re = 80000
| P a g e 73
Pr = 0.55
From Figure 12.29, heat transfer factor (jh) is:
Baffle cuts with 25% were chosen:
jh = 0.0023
hs = 668.82 W/m2 C
Overall Coefficient:
1
1
1
 

U o ho hod
d
d o ln  o 
 di    d o  1
 d  h
2k w
 i  id
  d o  1 
    
  d i  hi 
For fouling factors (coefficients) from table 12.2
Outside coefficient (fouling factor) =hod = 6000
Inside coefficient (fouling factor) =hid = 3000
Kw for steel at 100 C = 45 (W/m C)
So :
1/Uo = 0.37
Uo = 26.98W/m2 C
| P a g e 74
Tube Side Pressure Drop
  L     m
 u 2 
Pt  N p 8 j f     2.5 t 
  d i   w 
 2 
Np (number of tube passes) = 4
From Figure 12.24, friction factor (jf) is:
jf = 0.045
so the pressure drop of the tube side = 3.4 kPa
Shell Side Pressure Drop:
 D  L    0.14  u 2 
Ps  8 j f  s     s 
 d e  lB   w   2 
So the Pressure Drop of the shell side = 3195.7 kPa
Thickness
rj 
t
D
2
Pr j
SE j  0.6 P
 Cc
rj = inside radius of the shell, before corrosion allowance is added, inch
rj = 16.5 inch
P = maximum allowable internal pressure
P = 17.5 psi
Ej = Efficiency of joints expressed as a fraction
Ej = 0.85 (if spot examined)
| P a g e 75
Cc = Allowance for corrosion = 0.125 inch
S = Maximum allowable working stress, psi
S = 13700 psi
t = 0.15 inch = 3.8 mm
Material of Construction
Carbon Steel is chosen because it’s widely used and much cheaper than stainless steel and is nonreactive with the process components.
Working stress S = 13700 psi
t = 0.15 inch = 3.8 mm
| P a g e 76
Equipment Name
Cooler
Objective
cool stream from 329.9 to 152.9 C
Equipment Number
E-101
Designer
Abdullah Al-Shemali
Type
Shell and Tupe
Location
before Pump P-100
Utility
water
Material of Construction
Carbon Steel
Insulation
Fiber Glass
Cost
$ 72900
Operating Condition
Shell Side
Inlet temperature (oC)
329.9
Outlet temperature (oC)
152.9
Tube Side
Inlet temperature (oC)
25
Outlet temperature (oC)
94
Number of Tube Rows
4
Number of Tubes
739
Tube bundle Diameter (m)
0.772
Shell Diameter (m)
0.838
Q total (KW)
974.5
LMTD (oC)
176
U (W/m2 C)
27
Heat Exchanger Area (m2)
209.07
| P a g e 77
2.2. Abdulhadi’s Design
2.2.1. Distillation Column (T-100)
L=
58008.36 Mol/h
V=
140298.4 mol/h
L'=
218202.3 Mol/h
V'=
82891.72 mol/h
Slope of top operating line =
2.632378
Slope of the bottom operating line =
0.413464
assume column efficiency 52%
Number of real stages = 32
Physical Properties
Top
Bottom
ρV (kg/m3)
1.89549251 1.47164731
ρL (kg/m3)
769.8524
802.1781
SurfaceTen ion 0.024374
0.035985
M.wt(Kg/Kmol) 44.01578
33.58381
Column diameter
F LV top =
0.02051612
F LVbottom=
0.11274952
Take tray spacing as
From Figure 11.27
Top :
K1=
Bottom :
K1=
0.7 m
0.07
0.09
Correction for surface tensions
Top :
K1=
0.0728246
| P a g e 78
Bottom :
K1=
0.1012184
Flooding vapour velocity
Top :
Uf 1.46583707
m/s
Bottom : Uf 2.36099158
m/s
flooding at maximum flow
Design for 70%
rate
Top :
ûv =
1.02608595 m/s
Bottom :
ûv =
1.65269411 m/s
Maximum volumetric flow-rate
Top=
0.904975 m3/s
Bottom =
0.525454 m3/s
Net area required
Top =
0.881968 m2
Bottom=
0.317938 m2
Take downcomer area as
Column cross-sectioned area
Top =
1.002236
Bottom=
0.361293
12%
of total.
Column diameter
Top =
1.12964 m
Bottom=
0.67824 m
Liquid flow pattern
maximum volumetric liquid rate =2.5E-03
From figure 11.28 it is clear that a cross flow (single pass) plate can
be used
Provisional plate design
Column diameter Dc =
1.130 m
| P a g e 79
Column area Ac =
1.002 m2
Downcomer area Ad=
0.120 m2 at
Net area An =
0.882 m2
Active area Aa =
0.762 m2
Hole area Ah =
0.053 m2
Lw/Dc =
0.76
Weir length=
Take :
Weir
height
Hole diameter
Plate thickness
12%
take Aa
7%
(from Figure 11.31)
0.859 m
50
5
5
mm
mm
mm
Check weeping
Maximum liquid rate = 2.035574 Kg/s
Minimum liquid rate =1.424902 Kg/s
70% turn-down
weir crest :
Maximum how =
Minimum how =
15.446715
2
12.177781
2
mm liquid
mm liquid
at minimum rate hw + how = 62.17778 mm
K2 =30.3
From Figure 11.30
minimum vapour velocity through the holes(based on
the hole area)=9.84243277 m/s
actual minimum vapour velocity =6.898444 m/s
So minimum operating rate will be well above weep
point.
Plate pressure drop
Dry plate drop
Maximum vapour velocity through holes=
16.97285 m/s
| P a g e 80
From Figure 11.34, for plate thickness/hole dia. =
C0 =
0.82
hd =
40.08528 mm
hr =
15.58257 mm
total plate pressure drop
ht =
121.1146 mm
Downcomer liquid back-up
Downcorner pressure loss
Take hap = hw — 10 =
40 mm
The clearance area under the downcomer, Aap =
hdc=
0.906385 mm
Back-up in downcomer
hb =
187.4677 mm
=
0.187 m
1/2 (plate spacing+weir
0.187
<
height)=
--->
Column Height =
Check residence
time
tr=
8.862923 s
1
and Ah/Ap = Ah/Aa =
7%
0.034341 m2
0.375 so tray spacing is acceptable
24 m
>
3 A time of at least 3 seconds is recommended.
Check entrainment
uv=
0.595775 m/s
percent flooding
25.2%
F LV = 0.11275
from figure 11.29, = 0.05 less than 1 the upper limit of  can be taken as 0.1;
below this figure the effect on efficiency will be small As the per cent flooding is well below the
design figure of 70, the column diameter could be reduced, but this would increase the pressure drop.
Trial layout
Use cartridge-type construction. Allow 50 mm unperforated strip round plate edge; 50 mm wide
calming zones.
Perforated area
From Figure 11.32, at lw/Dc - 0.76
------>
angle subtended at plate edge by unperforated strip =
mean length, unperforated edge strips =
area of unperforated edge strips =
Mean length of calming zone =
0.820965
Area of calming zone =
0.082096
θc=
99 °
81 °
1.526305 m
0.076315 m2
m
m2
| P a g e 81
Total area for perforations, Ap =
Ah/Ap =
0.088381
0.603 m2
From Figure 11.33 lp/dh =
2.9 satisfactory, within 2.5 to 4.0
Number of holes
Area of one hole =
Numbers of holes =
1.9635E-05 m2
2716
Equipment Name
Distillation Column
Objective
To separate 99.5% pure Acetaldehyde
Equipment Number
T-100
Designer
Abdulhadi-Alsaleh
Type
Tray Column
Location
After heater E-103 and before pump P-101
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
Column Flow Rates
Feed (kgmole/hr)
217.6
Distillate (kgmole/hr)
82.29
Bottoms
(kgmole/hr)
135.3
Acetaldehyde
Heavy
Ethanol
Diameter (m)
1.13
Height (m)
24
Number of Trays
32
Reflux Ratio
15
Tray Spacing (m)
0.7
Type of tray
Sieve Tray
Number of Holes
2716
Key Components
Light
Dimensions
| P a g e 82
2.2.2. Distillation Column (T-102)
L=
58719.8
V=
L'=
737707.
7
V'=
Slope of top operating line =
Slope of the bottom operating line =
71507.3
3
71405.2
7
10.3312
8
0.82117
2
Physical Properties
assume column efficiency 85%
Number of real stages = 8
Top
Bottom
ρV (kg/m3)
1.88635408 0.80723948
ρL (kg/m3)
782.1087
947.808
SurfaceTension
0.026549
0.058616
M.wt(Kg/Kmol) 43.76854
18.03828
Column diameter
F LV top =
F LV bottom=
0.0403285
0.30150539
Take tray spacing as
0.9 m
From Figure 11.27
Top :
K1=
0.09
Bottom :
K1=
0.065
Correction for surface tensions
Top :
K1=
0.09524619
| P a g e 83
Bottom :
K1=
0.08059548
Flooding vapour velocity
Top :
Uf
1.93706948 m/s
Bottom :
Uf
2.76048029 m/s
Design for
Top :
Bottom :
60%
ûv =
ûv =
flooding at maximum flow rate
1.16224169 m/s
1.65628817 m/s
Maximum volumetric flow-rate
Top=
0.460879 m3/s
Bottom =
0.443221 m3/s
Net area required
Top =
0.396543 m2
Bottom=
0.267599 m2
Take downcomer area as
Column cross-sectioned area
Top =
0.450617
Bottom=
0.267599
12%
of total.
Column diameter
Top =
0.75746 m
Bottom= 0.58371 m
Liquid flow pattern
maximum volumetric liquid rate =
3.9E-03
From figure 11.28 it is clear that a cross flow (single pass) plate can be used
Provisional plate design
Column diameter Dc =
Column area Ac =
Downcomer area Ad=
Net area An =
Active area Aa =
Hole area Ah =
Lw/Dc =
Weir length=
0.757
m
0.451 m2
0.054 m2 at
12%
0.397 m2
0.342 m2
0.034 m2
take Aa
(from Figure
0.84 11.31)
0.636 m
10%
Take :
| P a g e 84
Weir height
Hole diameter
Plate thickness
50 mm
5 mm
5 mm
Check weeping
Maximum liquid rate =
Minimum liquid rate =
weir crest :
Maximum how =
Minimum how =
3.696382 Kg/s
2.587467 Kg/s
70% turn-down
25.1192562 mm liquid
19.8033564 mm liquid
at minimum rate hw + how =
From Figure 11.30, K2
=
69.8033 mm
30.5
minimum vapour velocity through the holes(based on the hole area)=
actual minimum vapour velocity =
9.05935 m/s
So minimum operating rate will be well above weep point.
13.5119
3 m/s
Plate pressure drop
Dry plate drop
Maximum vapour velocity through holes =
From Figure 11.34, for plate thickness/hole dia. =
C0 =
0.84
hd =
10.31079 mm
hr =
13.18833 mm
total plate pressure drop
ht =
98.61837 mm
12.9419 m/s
and Ah/Ap =
1 Ah/Aa =
10%
Downcomer liquid back-up
Downcorner pressure loss
Take hap = hw — 10 =
40 mm
The clearance area under the downcomer, Aap =
hdc=
3.897846 mm
Back-up in downcomer
hb =
177.6355 mm
=
0.178 m
0.025451 m2
| P a g e 85
0.178
--->
<
1/2 (plate spacing+weir height)=0.475 so tray spacing is acceptable
Column Height =
Check residence time
tr=
2.468042 s
8 m
>
2s
Check entrainment
uv=
1.117712 m/s
percent flooding
40.4897724
F LV =
0.301505 from figure 11.29, =
0.0027 less than 1
Trial
layout
Use cartridge-type construction. Allow 50 mm unperforated strip round plate edge; 50 mm
wide calming zones.
Perforated area
From Figure 11.32, at lw/Dc - 0.84
------>
angle subtended at plate edge by unperforated strip =
mean length, unperforated edge strips =
0.802586
area of unperforated edge strips =
0.040129
Mean length of calming zone =
0.537956 m
Area of calming zone
=
0.053796 m2
Total area for perforations, Ap =
0.249
Ah/Ap =
0.13779
From Figure 11.33 lp/dh =
θc=
115 °
65 °
m
m2
m2
2.5 satisfactory, within 2.5 to 4.0
Number of holes
Area of holes =
Numbers of holes =
1.9635E-05 m2
1745
| P a g e 86
Equipment Name
Objective
Equipment Number
Designer
Type
Location
Material of Construction
Insulation
Distillation Column
To recover Acetaldehyde from the bottoms of the Absorber T-102
T-102
Abdulhadi-Alsaleh
Tray Column
After the Absorber T-101
Carbon Steel
Phenolic Foam
Column Flow Rates
Feed (kgmole/hr)
679.1
Distillate (kgmole/hr)
12.8
Bottoms (kgmole/hr) 666.2
Key Components
Light
Acetaldehyde Heavy
Ethanol
Dimensions
Diameter (m)
0.757
Height (m)
8
Number of Trays
8
Reflux Ratio
7
Tray Spacing (m)
0.9
Type of tray
Sieve Tray
Number of Holes
1745
| P a g e 87
2.2.3. Heat Exchanger (Heater E-103)
Parameter
Unit
Value
Duty
kW
-7.17E+02
Process Stream (Shell Side):
Prameter
Unit
Tempreture Ti
C
Thermal Conductivty k
Inlet
Outlet
Mean
42.05
89.45
65.75
W/m.C
2.67E-01
2.67E-01
0.26726
Mass Density ρ
kg/m3
752.145
752.145
752.145
Viscosity μ
mPa.s
4.01E-01
4.01E-01
0.40144
2.9307
3.00974
2
Specfic Heat Cp
KJ/Kg.K
Mass Flow Rate
kg/s
3.0888
2.27
Low Pressure Steam (Tube Side):
Prameter
Unit
Inlet
Outlet
Mean
Temperture ti
C
125
105
115
Thermal Conductvity
W/m.C
2.67E-02
2.52E-02
0.02593
8
Mass Density
kg/m3
0.56597
0.59591
0.58094
Viscosity
mPa.s
0.013063
0.012239
0.01265
1
Specfic Heat Cp
KJ/Kg.K
2.03938888
9
0.372527688 1.20595
8
Mass Flow Rate
kg/s
18.05166667
| P a g e 88
Overall Heat Transfer Coefficients:
From table 12.1 :
150
Assume Uo=
Tlm 
R
W/m2.C
T1  t2   T2  t1 
 T  t  
ln  1 2 
 T2  t1  
T1  T2  ; S  t 2  t1 
t 2  t1
T1  t1
Tm  Ft Tlm
T1= 42.04 C
T2 = 89.45 C
t1 = 125 C
t2 = 105 C
∆Tlm = -47.95C
R = 2.37
S = 0.241
From Figure 12.19
Ft = 0.95
∆Tm = 0.95 * -47.95 = -45.55 C
| P a g e 89
Heat Transfer Area
Q =U A ∆Tm
U = 150 W/m2 °C
∆Tm = -45.55 C
Q = -771 * 1000 = -771000 W
Heat transfer area:
A = 112.84 m2
Layout and Tube Size
From Table 12.3
Assume Outler diameter (do)
50
mm
Assume inside diameter (di)
48
mm
Assume Length of tubes (L)
1.83
m
tringual Pitch =1.25 * dia.
62.5
mm
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
Assume 4 Tube Pass
| P a g e 90
do
mm
50
di
mm
48
flow rate
kg/s
18.05166667
density
kg/m3
0.58094
L
m
1.83
Ao=
m2
112.84
Area of one tube
m2
0.287455728
# of tubes
392.5407935
Tubes/Pass
98.13519839
Cross sectional area
m2
0.001809557
Area/pass
m2
0.177581271
velocity
m/s
174.9801821
Bundle and Shell Diameter
1
 N t  n1
Db  d o   ; K1 , n1  f No.Passes 
 K1 
Ds  Db  Re ading Fig .12.10
From table 12.4
K1 = 0.175
n1 = 2.285
From Figure 12.10:
Db = 1.46 m
Reading = 72 mm
So the value of Ds = 1535.6 mm
| P a g e 91
Tube side Heat Transfer Cofficient
Re 
cp
ut d i
; Pr 

k
Nu  jh Re Pr 0.33   
 w 
 kf
hi  Nu
 di
0.14
; jh  f (
L
)
di



Reynolds Number:
Re = 385688
Prandtl Number:
Pr = 0.58821
I/Di = 38.125
From Figure 12.23, heat transfer factor (jh) is:
Jh = 0.002
Nusselt number:
Nu = 647
Inside Coefficient (hi):
hi = 349.9 W/m2 C
| P a g e 92
Shell side heat transfer Coefficient:
As 
 pt  d o Ds lB
pt
us 
FlowRate
As 
de 
1. 1 2
2
pt  0.917 d o
do
Re 
cp
u s d e
; Pr 

k

Nu  jh Re Pr
 kf
hs  Nu
 de
0.33

 
  
w

0.14
; jh  f Re, buffle _ cut 



Take baffle spacing = 0.2*Ds
Triangular Pitch = 62.5 mm
do = 50 mm
Ds = 1535 mm
Ib = Baffle spacing * Ds = 307.1 mm
As = 0.0943 m2
de = 0.0355 m
us = 0.03197 m/s
Re = 2126.5
Pr = 1.811
From Figure 12.29, heat transfer factor (jh) is:
Baffle cuts with 25% were chosen:
jh = 0.01
| P a g e 93
Nu = 41.98
hs = 316 W/m2 C
Overall Coefficient:
d
d o ln  o 
1
1
1
 d i    d o  1
 

 d  h
U o ho hod
2k w
 i  id
  d o  1 
    
  d i  hi 
For fouling factors (coefficients) from table 12.2
Outside coefficient (fouling factor) =hod = 5000
Inside coefficient (fouling factor) =hid = 4000
Kw for steel at 100 C = 45 (W/m C)
ho = 316 W/m2 C
hi = 349.8 W/m2 C
di = 48 mm
do = 50 mm
So :
1/Uo = 0.006625
Uo = 150.9 W/m2 C
| P a g e 94
Tube Side Pressure Drop
  L     m
 u 2 





Pt  N p 8 j f     2.5 t 
  d i   w 
 2 
Np (number of tube passes) = 4
Re= 385688.4
ut (velocity) = 174.98 m/s
L/di = 38.125
From Figure 12.24, friction factor (jf) is:
jf = 0.002
so the pressure drop of the tube side = 111 kPa
Shell Side Pressure Drop:
 D  L    0.14  u 2 
Ps  8 j f  s     s 
 d e  lB   w   2 
Ds = 1535.6 mm
de = 0.0355 m
Ds/de = 43.25
L = 1.83 m
IB = 307.1 mm
| P a g e 95
L/IB = 5.96
us = 0.0319 m/s
Re = 2126.5
jf = 0.06
So the Pressure Drop of the shell side = 0.029 kPa
Thickness
rj 
t
D
2
Pr j
SE j  0.6 P
 Cc
D = Ds/1000 = 1.536 m = 60.46 inch
rj = inside radius of the shell, before corrosion allowance is added, inch
rj = 30.23 inch
P = maximum allowable internal pressure, Psi (from hysys)
P = 8.61 psi
Ej = Efficiency of joints expressed as a fraction
Ej = 0.85 (if spot examined)
Cc = Allowance for corrosion = 0.125 inch
S = Maximum allowable working stress, psi
S = 13700 psi
t = 0.147 inch = 3.74 mm
| P a g e 96
Material of Construction
Carbon Steel is chosen because it’s widely used and much cheaper than stainless steel and is nonreactive with the process components.
Working stress S = 13700 psi
t = 0.147 inch = 3.743 mm
Equipment Name
Heater
Objective
Heat stream from 42.05 to 89.45
Equipment Number
E-103
Designer
Abdulhadi Al-Saleh
Type
Shell and Tube
Location
Before the distillation unit T-100
Utility
Low Pressure Steam
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
Cost
$ 35600
Operating Condition
Shell Side
Inlet temperature (oC)
42.04
Outlet temperature (oC)
89.45
Tube Side
Inlet temperature (oC)
125
Outlet temperature (oC)
105
Number of Tube Rows
4
Number of Tubes
393
Tube bundle Diameter (m)
1.46
Shell Diameter (m)
1.54
Q total (Kw)
-771
LMTD (oC)
-47.95
U (W/m2 C)
150.9
Heat Exchanger Area (m2)
112.8
| P a g e 97
2.3 Abdulrhman’s Design
2.3.1. Heat Exchanger (Heater E-100)
Parameter
Unit
Value
Duty
kW
-4432
Prameter
Unit
Inlet
Tempreture Ti
C
63.2
329.85
196.54
Thermal Conductivty k
W/m.C
0.255
0.0432
0.148
Mass Density ρ
kg/m3
805.3
0.825
403.05
Viscosity μ
mPa.s
0.497
0.0153
0.256
Specfic Heat Cp
KJ/Kg.
K
3.56
2.29
2.925
Mass Flow Rate
kg/s
Process Stream (Shell Side):
Outlet
Mean
2.523
High Pressure Steam (Tube Side):
Prameter
Unit
Temperture ti
C
Thermal Conductvity
Inlet
Outlet
Mean
400
350
425
W/m.C
0.0674
0.049
0.058
Mass Density
kg/m3
0.284
0.352
0.318
Viscosity
mPa.s
0.028
0.023
0.025
Specfic Heat Cp
KJ/Kg.
K
2.14
2.04
2.089
Mass Flow Rate
kg/s
12.9
| P a g e 98
Overall Heat Transfer Coefficients:
From table 12.1 :
60
Assume Uo=
Tlm 
R
W/m2.C
T1  t2   T2  t1 
 T  t  
ln  1 2 
 T2  t1  
T1  T2  ; S  t 2  t1 
t 2  t1
T1  t1
Tm  Ft Tlm
T1= 63.2C
T2 = 329.8 C
t1 = 400 C
t2 = 350 C
∆Tlm = -153.8C
R = 5.33
S = 0.148
From Figure 12.19
Ft = 0.92
∆Tm = -141.5 C
| P a g e 99
Heat Transfer Area
Q =U A ∆Tm
U = 60 W/m2 °C
∆Tm = -141.5 C
Q = -4432 * 1000 = -4432000W
Heat transfer area:
A = 521.8 m2
Layout and Tube Size
From Table 12.3
Assume Outler diameter (do)
50
Mm
Assume inside diameter (di)
48
Mm
Assume Length of tubes (L)
2.2
M
tringual Pitch =1.25 * dia.
62.5
Mm
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
| P a g e 100
Assume 4 Tube Pass
do
mm
50
di
mm
48
flow rate
kg/s
12.97
density
kg/m3
0.32
L
m
2.2
Ao=
m2
521.8
Area of one tube
m2
0.345
# of tubes
1510.2
Tubes/Pass
377.5
Cross sectional area
m2
0.0018
Area/pass
m2
0.683
velocity
m/s
59.7
Bundle and Shell Diameter
1
 N  n1
Db  d o  t  ; K1 , n1  f No.Passes 
 K1 
Ds  Db  Re ading Fig .12.10
From table 12.4
K1 = 0.175
n1 = 2.285
From Figure 12.10:
Db = 2.6m
Reading = 72 mm
| P a g e 101
So the value of Ds = 2711.4 mm
Tube side Heat Transfer Cofficient
Re 
cp
ut d i
; Pr 

k
Nu  jh Re Pr 0.33   
 w 
 kf
hi  Nu
 di
0.14
; jh  f (
L
)
di



Reynolds Number:
Re = 35961.1
Prandtl Number:
Pr = 0.91
I/Di = 45.8
From Figure 12.23, heat transfer factor (jh) is:
Jh = 0.003
Nusselt number:
Nu = 118
Inside Coefficient (hi):
hi = 143.7 W/m2 C
| P a g e 102
Shell side heat transfer Coefficient:
As 
 pt  d o Ds lB
pt
us 
FlowRate
As 
de 
1. 1 2
2
pt  0.917 d o
do
Re 
cp
u s d e
; Pr 

k

Nu  jh Re Pr
 kf
hs  Nu
 de
0.33

 
  
w

0.14
; jh  f Re, buffle _ cut 



Take baffle spacing = 0.2*Ds
Triangular Pitch = 62.5 mm
do = 50mm
Ds = 2711.4 mm
Ib = Baffle spacing * Ds = 542.3 mm
As = 0.29 m2
de = 0.0355m
us = 0.02 m/s
Re = 1188.5
Pr = 3.6
From Figure 12.29, heat transfer factor (jh) is:
Baffle cuts with 25% were chosen:
jh = 0.014
| P a g e 103
hs = 35.1 W/m2 C
Nu = 35.1
Overall Coefficient:
1
1
1
 

U o ho hod
d
d o ln  o 
 di    d o  1
 d  h
2k w
 i  id
  d o  1 
    
  d i  hi 
For fouling factors (coefficients) from table 12.2
Outside coefficient (fouling factor) =hod = 3000
Inside coefficient (fouling factor) =hid = 1000
Kw for steel at 100 C = 45 (W/m C)
ho = 146.9 W/m2 C
hi = 143.7 W/m2 C
di = 48 mm
do = 50 mm
So :
1/Uo = 0.015
Uo = 64.7 W/m2 C
| P a g e 104
Tube Side Pressure Drop
  L     m
 u 2 
Pt  N p 8 j f     2.5 t 
  d i   w 
 2 
Np (number of tube passes) = 4
Re= 35961.1
ut (velocity) = 59.7 m/s
L/di = 45.8
From Figure 12.24, friction factor (jf) is:
jf = 0.0035
so the pressure drop of the tube side = 8.5 kPa
Shell Side Pressure Drop:
 D  L    0.14  u 2 
Ps  8 j f  s     s 
 d e  lB   w   2 
Ds = 2711.4 mm
de = 0.035 m
Ds/de = 76.3
L = 2.2 m
IB = 542.3 mm
L/IB = 4.05
us = 0.02 m/s
Re = 1188.5
| P a g e 105
jf = 0.07
So the Pressure Drop of the shell side = 0.01146 kPa
Thickness
rj 
t
D
2
Pr j
SE j  0.6 P
 Cc
D = Ds/1000 = 2.7 m = 106.7 inch
rj = inside radius of the shell, before corrosion allowance is added, inch
rj = 53.4 inch
P = maximum allowable internal pressure
P = 8.61 psi
Ej = Efficiency of joints expressed as a fraction
Ej = 0.85 (if spot examined)
Cc = Allowance for corrosion = 0.125 inch
S = Maximum allowable working stress, psi
S = 13700 psi
t = 0.16inch = 4.178 mm
Material of Construction
Carbon Steel is chosen because it’s widely used and much cheaper than stainless steel and is nonreactive with the process components.
Working stress S = 13700 psit = 0.16inch = 4.178 mm
| P a g e 106
Equipment Name
Heater
Objective
Heat stream from 63.2 to 329.85
Equipment Number
E-100
Designer
Abdulrahman Al-Mutairi
Type
Shell and Tube
Location
Before the Reactor
Utility
Steam
Material of Construction
Carbon Steel
Insulation
Fiber Glass
Cost
$ 128200
Operating Condition
Shell Side
Inlet temperature (oC)
63.2
Outlet temperature (oC)
329.85
Tube Side
Inlet temperature (oC)
400
Number of Tube Rows
4
Tube bundle Diameter (m)
2.6
Q total (KW)
-4432
U (W/m2 C)
60
Outlet temperature (oC)
350
Number of Tubes
1510.2
Shell Diameter (m)
2.7
LMTD (oC)
-141.5
Heat Exchanger Area (m2)
521.8
| P a g e 107
2.3.2. Heat Exchanger (Cooler E-102)
Parameter
Unit
Value
Duty
kW
1005
Process Stream (Shell Side):
Prameter
Unit
Inlet
Outlet
Mean
C
322
142
232
Thermal Conductivty k
W/m.C
0.0765
0.0521
0.064288
Mass Density ρ
kg/m3
3.8286
5.5033
4.66595
Viscosity μ
mPa.s
0.0195
0.0131
0.016273
Specfic Heat Cp
KJ/Kg.K
2.3646
1.9946
2.1796
Mass Flow Rate
kg/s
Tempreture Ti
2.5204
Cooling Water (Tube Side):
Prameter
Unit
Inlet
Outlet
Mean
C
25
45
35
Thermal Conductvity
W/m.C
0.6110
0.6315
0.62125
Mass Density
kg/m3
1007.3
995.96
1001.63
Viscosity
mPa.s
0.8904
0.65143
0.770915
Specfic Heat Cp
KJ/Kg.K
4.2055
4.231
4.21825
Mass Flow Rate
kg/s
Temperture ti
15.8277
| P a g e 108
Overall Heat Transfer Coefficients:
The overall heat transfer coefficient depends on the type of heat exchanger and the type of hot and
cold fluids as shown in the table 12.1
30
Assume Uo=
Tlm 
R
W/m2.C
T1  t2   T2  t1 
 T  t  
ln  1 2 
 T2  t1  
T1  T2  ; S  t 2  t1 
t 2  t1
T1  t1
Tm  Ft Tlm
T1= 322C
T2 = 142 C
t1 = 25 C
t2 = 45 C
∆Tlm = 185.6
R=9
S = 0.067
From Figure 12.19
Ft = 0.86
∆Tm = 0.86 * 185.6= 159.6 C
| P a g e 109
Heat Transfer Area
Q =U A ∆Tm
U = 30 W/m2 °C
∆Tm = 159.6 C
Q = 1005* 1000 = 1005000 W
Heat transfer area:
A = 209.8 m2
Layout and Tube Size
From Table 12.3
Assume Outler diameter (do)
25
mm
Assume inside diameter (di)
23
mm
Assume Length of tubes (L)
2.44
m
tringual Pitch =1.25 * dia.
31.25
mm
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
| P a g e 110
Assume 2 Tube Pass
do
mm
25
di
mm
23
flow rate
kg/s
15.83
density
kg/m3
1001.6
L
m
2.44
Ao=
m2
209.8
Area of one tube
m2
0.191
# of tubes
1094.9
Tubes/Pass
547.45
Cross sectional area
m2
0.0004
Area/pass
m2
0.227
velocity
m/s
0.069
Bundle and Shell Diameter
1
 N  n1
Db  d o  t  ; K1 , n1  f No.Passes 
 K1 
Ds  Db  Re ading Fig .12.10
From table 12.4
K1 = 0.249
n1 = 2.207
From Figure 12.10:
Db = 1.12 m
Reading = 75 mm
So the value of Ds = 1193.6 mm
| P a g e 111
Tube side Heat Transfer Cofficient
Re 
cp
ut d i
; Pr 

k
Nu  jh Re Pr 0.33   
 w 
 kf
hi  Nu
 di
0.14
; jh  f (
L
)
di



Reynolds Number:
Re = 2076.1
Prandtl Number:
Pr = 5.23
I/Di = 106
From Figure 12.23, heat transfer factor (jh) is:
Jh = 0.0028
Nusselt number:
Nu = 10
Inside Coefficient (hi):
hi = 271.13 W/m2 C
| P a g e 112
Shell side heat transfer Coefficient:
As 
 pt  d o Ds lB
pt
us 
FlowRate
As 
de 
1. 1 2
2
pt  0.917 d o
do
Re 
cp
u s d e
; Pr 

k


Nu  jh Re Pr 0.33   
 w 
 kf 
hs  Nu 
 de 
0.14
; jh  f Re, buffle _ cut 
Take baffle spacing = 0.2*Ds
Triangular Pitch = 31.25 mm
do = 25 mm
Ds = 1193.6 mm
Ib = Baffle spacing * Ds = 238.7 mm
As = 0.057 m2
de = 0.0177 m
us = 9.47 m/s
Re = 48244.7
Pr = 1.07
From Figure 12.29, heat transfer factor (jh) is:
Baffle cuts with 25% were chosen:
jh = 0.003
Nu = 86.2
hs = 312.1 W/m2 C
| P a g e 113
Overall Coefficient:
1
1
1
 

U o ho hod
d
d o ln  o 
 di    d o  1
 d  h
2k w
 i  id
  d o  1 
    
  d i  hi 
For fouling factors (coefficients) from table 12.2
Outside coefficient (fouling factor) =hod = 3000
Inside coefficient (fouling factor) =hid = 1000
Kw for steel at 100 C = 45 (W/m C)
ho = 312.1 W/m2 C
hi = 271.1 W/m2 C
di = 23 mm
do = 25 mm
So :
1/Uo = 0.037
Uo = 26.67 W/m2 C
Tube Side Pressure Drop
  L     m
 u 2 
Pt  N p 8 j f     2.5 t 
  d i   w 
 2 
Np (number of tube passes) = 2
Reynolds number: 2076.1
ut (velocity) = 0.07 m/s
| P a g e 114
L/di = 106
From Figure 12.24 we get the value of friction factor (jf):
jf = 0.0075
so the pressure drop of the tube side = 0.043 kPa
Shell Side Pressure Drop:
 D  L    0.14  u 2 
Ps  8 j f  s     s 
 d e  lB   w   2 
Ds = 1193.6 mm
de = 0.017 m
Ds/de = 67.24
L = 2.44 m
IB = 238.7 mm
L/IB = 10.22
us = 9.48 m/s
Re = 48244.7
jf = 0.04
So the Pressure Drop of the shell side = 79 kPa
| P a g e 115
Thickness
rj 
t
D
2
Pr j
SE j  0.6 P
 Cc
D = Ds/1000 = 1.19 m = 46.99 inch
rj = inside radius of the shell, before corrosion allowance is added, inch
rj = 23.5 inch
P = maximum allowable internal pressure, Psi (from hysys)
P = 8.61 psi
Ej = Efficiency of joints expressed as a fraction
Ej = 0.85 (if spot examined)
Cc = Allowance for corrosion = 0.125 inch
S = Maximum allowable working stress, psi
S = 13700 psi
t = 0.14 inch = 3.6 mm
Material of Construction
Carbon Steel is chosen because it’s widely used and much cheaper than stainless steel and is
non-reactive with the process components.
Working stress S = 13700 psit = 0.14 inch = 3.6 mm
| P a g e 116
Equipment Name
Cooler
Objective
Cool stream
Equipment Number
E-102
Designer
Abdulrahman Al-Mutairi
Type
Shell and Tube
Location
After the compressor
Utility
Cooling water
Material of Construction
Carbon Steel
Insulation
Cellular Glass
Cost
$ 69000
Operating Condition
Shell Side
Inlet temperature (oC)
322
Outlet temperature (oC)
142
Tube Side
Inlet temperature (oC)
25
Outlet temperature (oC)
45
Number of Tube Rows
4
Number of Tubes
1094.9
Tube bundle Diameter (m)
1.118
Shell Diameter (m)
1.193
Q total (KW)
1005
LMTD (oC)
159.6
U (W/m2 C)
30
Heat Exchanger Area (m2)
209.8
| P a g e 117
2.3.3. Heat Exchanger (Cooler E-104)
Parameter
Unit
Value
Duty
kW
2728
Process Stream (Shell Side):
Prameter
Unit
Inlet
Outlet
Mean
C
142
42.05
92.025
W/m.C
0.0521
0.0521
0.0521
Mass Density ρ
kg/m3
5.5033
21.448
13.47565
Viscosity μ
mPa.s
0.0131
0.0131
0.013079
Specfic Heat Cp
KJ/Kg.K
1.9946
3.1430
2.5688
Mass Flow Rate
kg/s
Tempreture Ti
Thermal Conductivty k
2.5204
Cooling water (Tube Side):
Prameter
Unit
Inlet
Outlet
Mean
C
25
40
32.5
W/m.C
0.6110
0.6315
0.62125
Mass Density
kg/m3
1007.3
995.96
1001.63
Viscosity
mPa.s
0.8904
0.65143
0.770915
Specfic Heat Cp
KJ/Kg.K
4.2055
4.231
4.21825
Mass Flow Rate
kg/s
Temperture ti
Thermal Conductvity
42.961
| P a g e 118
Overall Heat Transfer Coefficients:
From table 12.1 :
280
Assume Uo=
Tlm 
R
W/m2.C
T1  t2   T2  t1 
 T  t  
ln  1 2 
 T2  t1  
T1  T2  ; S  t 2  t1 
t 2  t1
T1  t1
Tm  Ft Tlm
T1= 142 C
T2 = 42.05 C
t1 = 25 C
t2 = 40 C
∆Tlm = 47.9C
R = 6.66
S = 0.128
From Figure 12.19
Ft = 0.95
∆Tm = 0.95 * 47.9 = 45.1 C
| P a g e 119
Heat Transfer Area
Q =U A ∆Tm
U = 280 W/m2 °C
∆Tm = 45.1 C
Q = 2728 * 1000 = 2728000 W
Heat transfer area:
A = 215.95 m2
Layout and Tube Size
From Table 12.3
Assume Outler diameter (do)
20
mm
Assume inside diameter (di)
18
mm
Assume Length of tubes (L)
6.1
m
tringual Pitch =1.25 * dia.
25
mm
Number of Tubes
AreaOfOneT ube   d o L
totalArea
areaOfOneT ube
# tubes
Tubes / Pass 
AssumedPasses
2
cross  Section  area  0.25d i
# tubes 
Area / pass  tubes / Pass cross  sec ton  area 
velocityu t  
FlowRate
 Area / Pass * Density
| P a g e 120
Assume 2 Tube Pass
do
mm
20
di
mm
18
flow rate
kg/s
42.96
Density
kg/m3
1001.6
L
M
6.1
Ao=
m2
215.95
Area of one tube
m2
0.383
# of tubes
563.45
Tubes/Pass
281.7
Cross sectional area
m2
0.00025
Area/pass
m2
0.072
Velocity
m/s
0.598
Bundle and Shell Diameter
1
 N  n1
Db  d o  t  ; K1 , n1  f No.Passes 
 K1 
Ds  Db  Re ading Fig .12.10
From table 12.4
K1 = 0.249
n1 = 2.207
From Figure 12.10:
Db = 0.66 m
Reading = 63 mm
So the value of Ds = 725.3 mm
| P a g e 121
Tube side Heat Transfer Cofficient
Re 
cp
ut d i
; Pr 

k
Nu  jh Re Pr 0.33   
 w 
 kf
hi  Nu
 di
0.14
; jh  f (
L
)
di



Reynolds Number:
Re = 13991.9
Prandtl Number:
Pr = 5.234
I/Di = 338.9
From Figure 12.23, heat transfer factor (jh) is:
Jh = 0.004
Nusselt number:
Nu = 96.6
Inside Coefficient (hi):
hi = 3335.5 W/m2 C
| P a g e 122
Shell side heat transfer Coefficient:
As 
 pt  d o Ds lB
pt
us 
FlowRate
As 
de 
1. 1 2
2
pt  0.917 d o
do
Re 
cp
u s d e
; Pr 

k


Nu  jh Re Pr 0.33   
 w 
 kf 
hs  Nu 
 de 
0.14
; jh  f Re, buffle _ cut 
Take baffle spacing = 0.2*Ds
Triangular Pitch = 25 mm
do = 20 mm
Ds = 725.3 mm
Ib = Baffle spacing * Ds = 145 mm
As = 0.021 m2
de = 0.014 m
us = 8.89 m/s
Re = 130066.6
Pr = 1.06
From Figure 12.29, heat transfer factor (jh) is:
Baffle cuts with 25% were chosen:
jh = 0.0019
| P a g e 123
Nu = 142.3
hs = 522.13 W/m2 C
Overall Coefficient:
d
d o ln  o 
1
1
1
 di    d o  1
 

 d  h
U o ho hod
2k w
 i  id
  d o  1 
    
  d i  hi 
For fouling factors (coefficients) from table 12.2
Outside coefficient (fouling factor) =hod = 5000
Inside coefficient (fouling factor) =hid = 1000
Kw for steel at 100 C = 45 (W/m C)
ho = 522.13 W/m2 C
hi = 335.5W/m2 C
di = 18 mm
do = 20 mm
So :
1/Uo = 0.0036
Uo = 279.1 W/m2 C
Tube Side Pressure Drop
  L     m
 u 2 
Pt  N p 8 j f     2.5 t 
  d i   w 
 2 
| P a g e 124
Np (number of tube passes) = 2
Re= 13991.9
ut (velocity) = 0.59 m/s
L/di = 338.8
From Figure 12.24, friction factor (jf) is:
jf = 0.045
so the pressure drop of the tube side = 44.6 kPa
Shell Side Pressure Drop:
 D  L    0.14  u 2 
Ps  8 j f  s     s 
 d e  lB   w   2 
Ds = 725.3 mm
de = 0.014 m
Ds/de = 51.1
L = 6.1 m
IB = 145.05 mm
L/IB = 42.05
us = 8.89 m/s
Re = 130066.6
jf = 0.035
| P a g e 125
So the Pressure Drop of the shell side = 56.6 kPa
Thickness
rj 
t
D
2
Pr j
SE j  0.6 P
 Cc
D = Ds/1000 = 0.725 m = 28.55 inch
rj = inside radius of the shell, before corrosion allowance is added, inch
rj = 14.3 inch
P = maximum allowable internal pressure, Psi (from hysys)
P = 8.61 psi
Ej = Efficiency of joints expressed as a fraction
Ej = 0.85 (if spot examined)
Cc = Allowance for corrosion = 0.125 inch
S = Maximum allowable working stress, psi
S = 13700 psi
t = 0.135 inch = 3.44 mm
Material of Construction
Carbon Steel is chosen because it’s widely used and much cheaper than stainless steel and is nonreactive with the process components.
Working stress S = 13700 psit = 0.135 inch = 3.44 mm
| P a g e 126
Equipment Name
Cooler
Objective
Cool stream
Equipment Number
E-104
Designer
Abdulrahman Al-Mutairi
Type
Shell and Tupe
Location
Before the Flash Seperator
Utility
Cooling Water
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
Cost
$ 73700
Operating Condition
Shell Side
Inlet temperature (oC)
142
Outlet temperature (oC)
42.05
Tube Side
Inlet temperature (oC)
25
Outlet temperature (oC)
40
Number of Tube Rows
2
Number of Tubes
563
Tube bundle Diameter (m)
0.66
Shell Diameter (m)
0.73
Q total (KW)
2728
LMTD (oC)
47.9
U (W/m2 C)
279.1
Heat Exchanger Area (m2)
215.95
| P a g e 127
2.3.4. Valve (VLV-100)
Inlet Pressure = 101.5 psia
Outlet Pressure = 42.1 psia
Density = 818 kg/m3
Viscosity = 0.424 cp
Flow Rate = 3.03E-3 m3/s
Assuming Turbulent Flow
D optimum =0.363*Q0.45*d0.13
=0.06386 m = 2.5 in
Re = (1280*density*Q)/(d opt * viscosity)
= 117255.8 > 2100 (Turbulent Flow )
Steel Pipe Dimensions
From Table D-13
Inside Diameter = 2.469 in
Outside Diameter = 2.88 in
Wall Thickness
= 0.411 in ( Standard Pipe )
Nominal Pipe Size = 2.5 in = 0.0635 m
| P a g e 128
Valve specification sheet:
Equipment Name
Valve
Objective
Decrease the flashed pressure
Equipment Number
VLV-100
Designer
Abdulrahman Al-Mutairi
Type
Flanged Globe valve
Location
Before E-103
Material of Construction
Stainless steel
Insulation
polystyrene
Cost ($)
220
Operating Condition
Operating Temperature (oC)
42.05
Operating Pressure (psig)
101.53
Flow Rate (Kmole/hr)
252.81
Pressure Drop (psig)
59.47
| P a g e 129
2.4. Hamed’s Design
2.4.1. Absorber (T-101)
Table.1: Physical properties of the Absorber.
Property
Gas Flow rate (kg/h)
Liquid Flow rate (kg/h)
Gas density (kg/m3)
Liquid density (kg/m3)
Liquid viscosity (N.s/m2)
Gas Molecular weight
(kg/kmol)
Liquid Molecular weight
(kg/kmol)
Liquid surface tension
(dyne/cm)
FLV top
L

V
 v

 L
L
FLV bottom 
V



0.5
 v

 L




12070  0.02 


294.02  972.81 
0.5

Top
294.02
12070
0.02
972.81
0.00040126
Bottom
748.39
12524
0.0566
963.15
0.000365
2.7887
6.605
18.015
18.476
64.188
63.421
0.5
12524  0.0566 


748.39  963.15 
 0.186
0.5
 0.128
Using Tray spacing = 0.6
Find K1,top K1,bottom from figure 11.27
K1,top = 0.085, K1,bottom = 0.09
K1 = (ƣ/ƣwater)0.2 K1
(Correction formula)
K1,top = (64.188/20)0.2 * 0.085 = 0.107
K1,bottom = (63.421/20)0.2 * 0.09 = 0.113
| P a g e 130
U f ,top
 (  V ) 

 K 1  L

V


0.5
 (  V ) 

U f ,bottom  K 1  L
V


 (972.81  0.02) 
 0.107

0.02


0.5
0.5
 23.67 m / s
 (963.15  0.0566) 
 0.113

0.0566


0.5
 14.79 m / s
U V ,top  Percentage Flooding x U f  0.85x23.67  20.12 m / s
U V ,bottom  Percentage Flooding x U f  0.85 x14.79  12.57 m / s
Vmax, top 
Vtop * MwtV
V
Vmax, bottom 
Anet ,top 

294.02
 4.08 m 3 / s
0.02 * 3600
Vbottom * MwtV
V

748.39
 3.67 m 3 / s
0.0566 * 3600
V max
4.081

 0.21 m 2
UV
20.12
Anet ,bottom 
V max
3.67

 0.29 m 2
UV
12.57
Taking downcomer area of 12% of total.
Acs ,top  0.21 /(1  .12)  0.23 m 2
Acs ,bottom  0.29 /(1  .12)  0.33 m 2
4

Dtop   Anet 


0.5
4

Dbottom   Anet 


take D  0.65m
4 

  0.23 *

3.14 

0.5
0.5
4 

  0.33 *

3.14 

 0.54m
0.5
 0.65m
Since column diameter is greater than 0.6 m, it’s clearly that the absorber is a tray column.
Liquid Flow pattern
max volumetric liquid rate 
LxMwt
L

12524
 0.0036 m 3 / s
963.15 * 3600
From Figure, single pass (cross flow) is used
| P a g e 131
AC 

4
D2 
3.14
(0.65) 2  0.33m 2
4
Down comer area Ad = 0.12*0.33 =0.04 m2
An  AC  Ad  0.29m 2
Aa  Ac  2 Ad  0.25 m 2
Ah  0.1xAa  0.0252 m 2
Ad
x100  12
Ac
from figure 11.31,
Lw
 0.757
Dc
weir length  0.757 * D  0.49 m
assume :
weir height hw  50mm
hole diameter d h  5mm
plate thickness  5mm
Maximum liquid rate (Lwd) = (12524/3600) = 3.48 kg/s
Turndown percentage = 70%
Minimum liquid rate = 3.48*0.7 = 2.44 kg/s
max how
min how
2
2
2
3
2
 max liquid rate  3
3.48

3
  750
 750
  28.317 mm liquid
 963.15 x0.49 
  L xweir length 
 min liquid rate 
 28.317  3
  750
 750
  22.32 mm liquid
 963.15 x0.49 
  L xweir length 
At minimum rate hw + how = 50 + 22.32 = 72.32 mm liquid
From figure 11.30 , K2 = 30.6
| P a g e 132
U h(min) 
K 2  0.9(25.4  hole diameter)

0.5

31.2  0.9(25.4  5)
 51.45 m / s
0.0566 0.5
Taking turndown percentage of 70%
actual min . vapor velocity 
Uh 
min . vapor rate 3.67 x0.7

 101.88 m / s
Ah
0.025
liquidflow rate 3.67

 145.54 m / s
Ah
0.025
from figure 11.34
plate thickness 5
 1
hole diameter 5
Ah
 0.1
Ap
C o  0.84
U
hd  51 h
 Co
hr 



12.5 x103
L
2
 V

 L

 145.54   0.0566 
  51
 
  89.976 mm liquid
 0.84   963.15 

2
12.5 x10 3

 12.978 mm liquid
963.15
hap  hw  10  50  10  40mm
area under apron Aap  weir lengthxhap  0.492x40 x10 3  0.0197 m 2
2
2
 max . liquid rate 
3.479




hdc  166
 166
  5.584mm


 L xAap
 963.15 x0.0197 


hb  hw  hdc  ht  how  0.2651 m
tr 
hb xAd x L 0.265 x0.0398 x963.15

 2.925 sec
Lwd
3.4789
| P a g e 133
UV 
volumetric flow rate 3.673

 12.57m / s
An
0.292
Percent Flooding  80%
Area of one hole = 3.14/4 (Dh)2 = 3.14/4*(5/1000)2 = 0.000019625 m2
Total no. of holes = 0.02523/0.000019625 = 1286
Pxri


678.7 x0.32518


  CC  
t  
  3 / 1000  0.00576 m  5.76 mm
 94500 x0.85  0.6 x780 
 SxEj  0.6 xP 
To calculate number of stage we should get the equilibrium and operating line from Hysys,
then we get the following graph.
1,2
1
0,8
Equilibrium line
0,6
Operating line
0,4
0,2
0
0
0,2
0,4
0,6
0,8
1
1,2
From graph number of stage = 12
Actual number of stage = 12/0.75 = 16 stage (where 0.75 represents the efficiency of tray
column)
Height of Absorber = (Actual number of stage * tray spacing) + D
= (16*0.6) + 0.65 = 10.25 m
| P a g e 134
Absorber
Equipment Name
To separate Hydrogen from
Acetaldehyde
Objective
T-101
Equipment Number
Designer
Hamed Alazmi
Type
Tray Absorber
after Flash Tank V-101
Location
Material of Construction
Carbon Steel
Insulation
Polystyrene
$ 18600
Cost ($)
Column Flow Rates
Gas flow
rate(kgmole/hr)
113
Liquid flow rate
(kgmole/hr)
0.65
Height (m)
670
Dimensions
Diameter (m)
10.25
| P a g e 135
2.4.2. Pump (P-100)
Mass Flow rate = 21498 Ib/hr = 5.97 Ib/s
Density (ρ) = 50.518 Ib/ft3
Pressure difference (ΔP) = P2 – P1= 2533.4 - 2116.1 = 417.3 Ib/ft2
Gravity (G) = 32.174 ft/sec2
V = m/ ρ
V = 5.97/50.518 = 0.118 ft3/sec
γ= ρ * G
γ = 50.518 * 32.174 = 1625.36 Ib/ft3
ha= ∆P/ γ
ha= 417.3/1625.36= 0.2567 ft
WHP = γ*V*ha/746
WHP = (1625.36*0.118*0.2567)/550= 0.0897 hp
η = WHP/BHP
0.75 = 0.0897/BHP
BHP = 0.1196 hp
| P a g e 136
Pump
Equipment Name
Moving an incompressible liquid from lower to higher
pressure
Objective
P-100
Equipment Number
Hamed Alazmi
Designer
Centrifugal
Type
before Heater E-100
Location
Stainless Steel
Material of Construction
Polystyrene
Insulation
$ 8000
Cost
Operating Condition
InletTemperature (oC)
66.75
OutletTemperature (oC)
104.4
Inlet Pressure(psia)
14.7
Outlet Pressure(psia)
17.59
Efficiency (%)
.75
Power (Hp)
0.1196
| P a g e 137
2.4.3. Pump (P-101)
Mass Flow rate = 11853 Ib/hr = 3.2925 Ib/s
Density (ρ) = 50.546 Ib/ft3
Pressure difference (ΔP) = P2 – P1= 6265.6 – 5012.5 = 1253.1 Ib/ft2
Gravity (G) = 32.174 ft/sec2
V = m/ ρ
V = 3.2925/50.546 = 0.0651 ft3/sec
γ= ρ * G
γ = 50.546 * 32.174 = 1626.267 Ib/ft3
ha= ∆P/ γ
ha= 1253.1/1626.267= 0.771 ft
WHP = γ*V*ha/746
WHP = (1626.267*0.0651*0.771)/550= 0.148 hp
η = WHP/BHP
0.75 = 0.148/BHP
BHP = 0.19788 hp
| P a g e 138
Equipment Name
Pump
Moving an incompressible liquid from lower to higher
pressure
Objective
Equipment Number
P-101
Designer
Hamed Alazmi
Type
Centrifugal
Location
after distillation T-101
Material of Construction
Stainless Steel
Insulation
Polystyrene
Cost
$ 8000
Operating Condition
Inlet Temperature (oC)
104.4
Outlet Temperature (oC)
104.4
Inlet Pressure (psia)
34.81
Outlet Pressure (psia)
43.51
Efficiency (%)
0.75
Power (Hp)
0.197
| P a g e 139
2.5. Isam’s Design
2.5.1 Distillation Column (T-103)
Table.2.4.1: Physical properties .
Property
Vapor Flow rate (kmol/h)
Liquid Flow rate (kg/h)
Vapor density (kg/m3)
Liquid density (kg/m3)
Molecular weight (kg/kmol)
surface tension (N/m)
Top
173.8
95
3.273
739.7
42.45
0.0225
Bottom
173.8
230.2
2.217
827.2
29.60
0.046
Column diameter
FLV top
L

V
 v 
 
 L 
L
FLV bottom 
V
0.5
 v 
 
 L 
95  3.273 



173.8  739.7 
0.5
0.5




230.2  2.217 

173.8  827.2 






 0.0364
0.5
 0.0686
Take tray spacing = 0.73 m
Find K1 from Figure 11.27
Top K1 =0.11
Bottom K1 =0.11
Correction for surface tensions
Top K1 =0.068
Bottom K1 =0.078
| P a g e 140
U f ,top
 (   V ) 

 K 1  L

V


U f ,bottom
0.5
 (   V ) 

 K 1  L

V


 (739.7  3.273) 
 0.068

3.273


0.5
0.5
 (827.2  2.217) 
 0.078

2.217


 1.01 m / s
0.5
 1.50 m / s
U V ,top  Percentage Flooding x U f  0.5 x1.01  0.51 m / s
U V ,bottom  Percentage Flooding x U f  0.5 x1.50  0.75m / s
Vmax, top 
Vtop * MwtV
V
Vmax, bottom 
Anet ,top 

173.8 * 42.45
 0.626 m 3 / s
3.273 * 3600
Vbottom * MwtV
V

173.8 * 29.6
 0.645 m 3 / s
2.217 * 3600
Vmax 0.626

 1.24 m 2
UV
0.51
Anet ,bottom 
Vmax 0.645

 0.857 m 2
UV
0.75
Taking downcomer area of 20% of total.
Adtop 
1.24
 1.54m 2
1  0.2
Adbottom 
Dtop
0.857
 1.07 m 2
1  0.2
4

  Adtop 


0.5
4

 1.54 


4

Dbottom   Adbottom 


take D  1.4 m
0.5
0.5
 1.402 m
4

 1.07 


0.5
 1.168 m
Liquid flow pattern
max volumetric liquid rate 
LxMwt
L

230.2 * 29.6
 0.0023 m3 / s
827.2 * 3600
From Figure 11.28, Gross flow plate can be used.
| P a g e 141
Provisional plate design
AC 

4
D2 

4
(1.402) 2  1.545 m 2
Down comer area Ad = 0.2*1.545 =0.309 m2
An  AC  Ad  1.545 - 0.309  1.236 m 2
Aa  Ac  2 Ad  1.545 - 2 * 0.309  0.927 m 2
Ah  0.06 xAa  0.056 m 2
Ad
x100  20
Ac
from figure 11.31,
Lw
 0.86
Dc
weir length  0.86 * D  1.206 m
assume :
weir height hw  50mm
hole diameter d h  5mm
plate thickness  5mm
Check weeping
maxliquid rate 
230.2 * 29.6
 1.89 kg / s
3600
Turndown percentage = 70%
Minimum liquid rate = 0.7*1.89 = 1.33 kg/s
Weir Crest
2
2
max how
 max liquid rate  3
1.89

3
  750
 750
  11.5 mm liquid
 827.2 x1.206 
  L xweir length 
min how
 min liquid rate  3
1.33

3
  750
 750
  9.06 mm liquid
 827.2 x1.206 
  L xweir length 
2
2
| P a g e 142
At minimum rate hw + how = 50 + 9.06 = 59.06 mm liquid
From figure 11.30 , K2 = 30.3
U h (min) 
K 2  0.9(25.4  hole diameter)

0.5
actual min . vapor velocity 

30.3  0.9(25.4  5)
 8.02 m / s
2.217 0.5
min . vapor rate 0.7 x0.645

 8.12 m / s
Ah
0.056
So minimum operating rate will be well above weep point.
Plate pressure drop
Uh 
liquidflow rate 0.645

 11.6 m / s
Ah
0.056
from figure 11.34
plate thickness 5
 1
hole diameter 5
Ah
 0.06
Ap
  C o  0.81
U
hd  51 h
 Co
hr 



12.5 x103
L
2
 V

 L


 11.6   2.217 
  51
 
  28 mm liquid
0
.
81
827.2





2
12.5 x10 3
 15.11 mm liquid
827.2
ht  hd  hr  hw  how  104.6 mmliquid
Downcomer liquid back-up
hap  hw  10  50  10  40mm
| P a g e 143
area under apron Aap  weir lengthxhap  1.206 x40 x10 3  0.0482 m 2
2
2
 max . liquid rate 
1.89

  166
hdc  166
 0.374 mm




xA
827
.
2
x
0.0482


L
ap


hb  hw  hdc  ht  how  166.47 mm
166< 0.5(plate spacing + weir height) =390 mm so tray spacing is acceptable.
Check residence time
tr 
hb xAd x L 0.166474 x0.309 x827.2

 22.4  3s
Lwd
1.89
Check entrainment
UV 
volumetric flow rate 0.644

 0.522m / s
An
1.236
F LV =0.0686 from figure 11.29 =0.01 less than 1 (the upper limit of  can be taken as 0.1;
below this figure the effect on efficiency will be small)
Perforated area
From Figure 11.32, at lw/Dc - 0.86------>θ c = 118°
angle subtended at plate edge by unperforated strip =180-118=62°
mean length, unperforated edge strips =1.46 m
area of unperforated edge strips =0.0731 m2
Mean length of calming zone =1.03 m
Area of calming zone =0.103 m2
Total area for perforations, Ap =0.751 m2
Ah/Ap =0.074
From Figure 11.33 lp/dh = 3.6 satisfactory, within 2.5 to 4.0
| P a g e 144
Number of holes
Area of one hole = π/4 (Dh)2 = π/4*(5/1000)2 = 0.000019635 m2
Total no. of holes = 0.056/0.000019635 = 2832
Column Height
From shortcut hand calculation and assuming column efficiency 50%
Actual number of stage = 14.6/0.5= 30 stage
Height of Column = (Actual number of stage * tray spacing) + D
= (30*0.73) + 1.4 = 23.3 m
| P a g e 145
Equipment Name
Distillation Column
To recover Ethanol & Ethyl-Acetate from
impurities
Objective
Equipment Number
T-103
Designer
Isameldeen El-Badawi
Type
Tray Column
Location
After the heater E-103
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
Cost ($)
230560
Column Flow Rates
Feed (kgmole/hr)
Distillate (kgmole/hr)
135.21
78.8
Bottoms (kgmole/hr)
56.41
Heavy
Water
Key Components
Light
Ethanol
Dimensions
Diameter (m)
1.4
Height (m)
23.3
Number of Trays
30
Reflux Ratio
1.2
Tray Spacing
0.73
Type of tray
Sieve Tray
Number of Holes
2832
Cost
Vessel ($)
116300
Trays ($)
16500
Condenser Unit ($)
29700
Reboiler ($)
47100
| P a g e 146
2.5.2 Distillation Column (T-104)
Table 2.4.2: Physical properties.
Property
Vapor Flow rate (kmol/h)
Liquid Flow rate (kg/h)
Vapor density (kg/m3)
Liquid density (kg/m3)
Molecular weight (kg/kmol)
surface tension (N/m)
Top
212.9
208.4
4.64
771.3
59.5
0.0251
Bottom
212.9
287.2
3.22
736
41.6
0.0221
Column diameter
FLV top
L

V
FLV bottom
 v

 L
L

V



0. 5
 v

 L



208.8  4.64 



212.9  771.3 
0.5
0. 5




287.2  3.22 

212.9  736. 






 0.0542
0.5
 0.092
Take tray spacing = 0.76 m
Find K1 from Figure 11.27
Top K1 =0.12
Bottom K1 =0.11
Correction for surface tensions
Top K1 =0.075
Bottom K1 =0.067
U f ,top
 (   V ) 

 K 1  L
V


U f ,bottom
0.5
 (   V ) 

 K 1  L

V


 (771.3  4.64) 
 0.075 * 

4.64


0.5
 (736  3.22) 
 0.067

3.22


0.5
 0.968 m / s
0.5
 1.02 m / s
| P a g e 147
U V ,top  Percentage Flooding x U f  0.75 x0.968  0.726 m / s
U V ,bottom  Percentage Flooding x U f  0.75 x1.02  0.761 m / s
Vtop * MwtV
Vmax, top 
V
Vmax, bottom 
Anet ,top 

212.9 * 59.5
 0.757 m 3 / s
4.64 * 3600
Vbottom * MwtV
V

212.9 * 41.6
 0.764 m 3 / s
3.22 * 3600
Vmax 0.757

 1.04 m 2
UV
0.726
Anet ,bottom 
Vmax 0.764

 1.00 m 2
UV
0.761
Taking downcomer area of 14% of total.
Adtop 
1.04
 1.21 m 2
1  0.14
Adbottom 
1.00
 1.17 m 2
1  0.14
4

Dtop   Adtop 


0.5
4

 1.21 


4

Dbottom   Adbottom 


take D  1.24 m
0.5
0.5
 1.24 m
4

 1.17 


0.5
 1.22 m
Liquid flow pattern
max volumetric liquid rate 
LxMwt
L

287.2 * 41.6
 0.0045 m 3 / s
736 * 3600
From figure 11.28 it is clear that a Gross flow (single pass).
Provisional plate design
AC 

4
D2 

4
(1.24) 2  1.21 m 2
Downcomer area Ad = 0.14*1.21 =0.17 m2
An  AC  Ad  1.21 - 0.17  1.04 m 2
| P a g e 148
Aa  Ac  2 Ad  1.212 - 2 * 0.17  0.873 m 2
Ah  0.06 xAa  0.052 m 2
Ad
x100  14
Ac
from figure 11.31,
Lw
 0.78
Dc
weir length  0.78 * D  0.969 m
Take :
weir height hw  50mm
hole diameter d h  5mm
plate thickness  5mm
Check weeping
max .liquid rate 
287.2 * 41.6
 3.32 kg / s
3600
Turndown percentage = 70%
Min. liquid rate = 0.7*3.32 = 2.32 kg/s
2
2
max how
 max liquid rate  3
 3.32  3
  750
 750
  20.9 mm liquid

xweir
length
736
x
0.969


 L

min how
 min liquid rate  3
2.32

3
  750
 750
  16.5 mm liquid
 771.3x0.969 
  L xweir length 
2
2
At minimum rate hw + how = 50 + 16.5 = 66.5 mm liquid
From figure 11.30, K2 = 30.4
U h (min) 
K 2  0.9(25.4  hole diameter)

0.5

30.4  0.9(25.4  5)
 6.71 m / s
3.22 0.5
| P a g e 149
actual min . vapor velocity 
min . vapor rate 0.7 x0.762

 10.21 m / s
Ah
0.052
So minimum operating rate will be well above weep point.
Plate pressure drop
Uh 
liquidflow rate 0.764

 14.6m / s
Ah
0.052
from figure 11.34
plate thickness 5
 1
hole diameter 5
Ah
 0.06
Ap
  C o  0.81
U
hd  51 h
 Co
hr 



12.5 x103
L
2
 V

 L


 14.6   3.22 
  51
 
  72.4 mm liquid
 0.81   736.3 

2
12.5 x10 3
 17 mm liquid
736.3
ht  hd  hr  hw  how  160.3 mmliquid
Downcomer liquid back-up
hap  hw  10  50  10  40mm
area under apron Aap  weir lengthxhap  0.969x40 x10 3  0.0388 m 2
2
2
 max . liquid rate 
3.32




hdc  166
 166
  2.25mm


 L xAap
 736.3 x0.0388 


hb  hw  hdc  ht  how  233.45mm
233.45< 0.5(plate spacing + weir height) =405 mm so tray spacing is acceptable.
| P a g e 150
Check residence time
tr 
hb xAd x L 0.233x0.17 x736.3

 8.8  3s
Lwd
3.32
Check entrainment
UV 
volumetric flow rate 0.764

 1.45m / s
An
1.043
F LV =0.089 From figure 11.29, =0.025 less than 1
(the upper limit of y can be taken as 0.1; below this figure the effect on efficiency will be
small).
Perforated area
From Figure 11.32, at lw/Dc - 0.78------>θ c = 102°
angle subtended at plate edge by unperforated strip =180-102=78°
mean length, unperforated edge strips =1.623 m
area of unperforated edge strips =0.08116 m2
Mean length of calming zone =0.9067 m
Area of calming zone =0.09067 m2
Total area for perforations, Ap =0.701 m2
Ah/Ap =0.0747
From Figure 11.33 lp/dh = 3.2 satisfactory, within 2.5 to 4.0
Number of holes
Area of one hole = π/4 (Dh)2 = π/4*(5/1000)2 = 0.000019635 m2
Total no. of holes = 0.052/0.000019635 = 2668
| P a g e 151
Column Height
From shortcut Calculation
Actual number of stage = 30 stage
Height of Column = (Actual number of stage * tray spacing) + D
= (30*0.76) + 1.24 = 24 m
| P a g e 152
Equipment Name
Distillation Column
Objective
To recover Ethyl-Acetate from Ethanol
Equipment Number
T-104
Designer
Isameldeen El-Badawi
Type
Tray Column
Location
After the heater E-103
Material of Construction
Carbon Steel
Insulation
Phenolic Foam
186010
Cost ($)
Column Flow Rates
Feed (kgmole/hr)
78.8
Distillate (kgmole/hr)
4.43
Bottoms (kgmole/hr)
74.37
Key Components
Light
EthylAcetate Heavy
Water
Diameter (m)
1.24
Height (m)
24
Number of Trays
30
Reflux Ratio
47
Tray Spacing
0.76
Type of tray
Sieve Tray
Number of Holes
2668
Dimensions
Cost
Vessel ($)
105500
Trays ($)
15000
Condenser Unit ($)
29700
Reboiler ($)
22000
| P a g e 153
2.5.3 Pump P-102
Mass Flow rate (ṁ) = 2.048 Ib/s
Density (ρ) = 46.18 Ib/ft3
Pressure difference (ΔP) = P2 – P1= 6056.8 - 5012.5 = 1044.3 Ib/ft2
Gravity (G) = 32.174 ft/sec2
V̇ =
ṁ
ρ
V̇= 2.048/46.18=0.0444 ft3/sec
γ=ρ*G
γ = 46.18* 32.174 = 1485.7 Ib/ft3
ha=
ΔP
γ
ha=1044.3/1485.7 = 0.703 ft
WHP =
WHP=
γV̇ha
550
1485.7∗0.0444∗0.703
550
= 0.084 hp
Assume η =0.20
BHP =
WHP
0.084
η
0.2
=
=0.42 hp
| P a g e 154
Equipment Name
Pump
Objective
To move fluid
Equipment Number
P-101
Designer
Isameldeen Elbadawi
Type
Diaphragm Pump
Location
Before distillation T-104
Material of Construction
Carbon Steel
Insulation
Polystyrene
Cost
$ 17600
Operating Condition
Inlet Temperature (oC)
102.5
Outlet Temperature (oC)
102.6
Inlet Pressure (psia)
34.81
Outlet Pressure (psia)
42.06
Efficiency (%)
20
Power (Hp)
0.42
| P a g e 155
2.5.4 Valve (VLV-101)
Inlet Pressure = 94.27psia
Outlet Pressure = 14.5 psia
Density = 961.7 kg/m3
Viscosity = 0.3138 cp
Flow Rate = 3.63*10-3 m3/s
Assuming Turbulent Flow
D optimum =0.363*Q0.45*d0.13
=0.0734 m = 2.9 in
Re = (1280*density*Q)/(d opt * viscosity)
= 201434 > 2100 (Turbulent Flow )
Steel Pipe Dimensions
From Table D-13
Inside Diameter = 2.9 in
Outside Diameter = 3.5 in
Wall Thickness
= 0.6 in ( Extra Strong Pipe )
Nominal Pipe Size = 3 in = 0.07625 m
| P a g e 156
Equipment Name
Valve
Objective
Decrease the pressure
Equipment Number
V-101
Designer
Isameldeen El-Badawi
Type
Flanged Globe valve
Location
Before Distillation T-102
Material of Construction
Carbon steel
Insulation
polystyrene
Cost ($)
250
Operating Condition
Operating Temperature (oC)
69.46
Operating Pressure (psig)
97.6
Flow Rate (Kmole/hr)
677.9
Pressure Drop (psig)
19.2
| P a g e 157
3. References
Web:
1.Wikipedia : http://en.wikipedia.org/wiki/Packed_bed
http://en.wikipedia.org/wiki/Gas_compressor
http://en.wikipedia.org/wiki/Vapor-liquid_separator
http://en.wikipedia.org/wiki/Valve
2.RPI: http://www.rpi.edu/dept/chem-eng/Biotech-Environ/IMMOB/packbed.htm
3.NIST:
http://kinetics.nist.gov/kinetics/ReactionSearch?r0=2348461&r1=12385136&r2=0&r3=0&r4=
0&p0=75070&p1=1333740&p2=0&p3=0&p4=0&expandResults=true&
4.Matrostech: http://www.matrostech.com/downloads/AMT-SR%20brochure.pdf
5.Uniroma1:http://ingchim.ing.uniroma1.it/~mazzarot/pagina%20mia%20internet/PIC/Coulson&%20
Richardson%20-%20Cap.10%20Gas-Liquid%20Separation.pdf
6.IITM: http://nptel.iitm.ac.in/courses/Webcourse-contents/IIScBANG/Heat%20and%20Mass%20Transfer/pdf/M7/Student_Slides_M7.pdf
7.Engvalves: http://www.engvalves.com/itemfiles/valveselectionessentials.pdf
8.Umich :https://controls.engin.umich.edu/wiki/index.php/ValveTypesSelection#Introduction
http://articles.compressionjobs.com/articles/oilfield-101/4393-valves-pipelines-gate-globe-needleangle-plug-ball-butterfly-check?showall=1
9.Matche: http://www.matche.com/EquipCost
10.Engineeringtoolbox :http://www.engineeringtoolbox.com/insulation-temperatures-d_922.html
11. NCL :http://lorien.ncl.ac.uk/ming/distil/distilint.htm
12.Rubbersealing : http://www.rubbersealing.com/images/Bubble.jpg
13. Euroslotkdss:http://www.euroslotkdss.com/mtri/tower-internals/distillation-trays.html
14. FLW: www.flw.com/datatools
15. Righthouse : http://www.righthouse.co.nz/products/insulation/polystyrene
| P a g e 158
Books:
16. Coulson & Richarddson (Volume 6), “Chemical Engineeing Design”, 3th edition.
17. Elements of Chemical Reaction Engineering; H. Scott Fogler; Third Edition;
Prentice-Hall, Inc
18. Max S. Peters & Klaus D. Timmerhaus, and Ronald E. West, “Plant Design and Economics
for Chemical Engineers”, 5th edition.
19. Richard M.Felder & Ronald W.Rousseau “Elementry Principles of Chemical Process”, 3th
edition.
| P a g e 159
4. Appendix (Design Figures)
4.1Column Design Figures
| P a g e 160
| P a g e 161
| P a g e 162
| P a g e 163
| P a g e 164
| P a g e 165
| P a g e 166
| P a g e 167
| P a g e 168
4.2 Cooler & Heater Design Figures
| P a g e 169
| P a g e 170
| P a g e 171
| P a g e 172
Cooler & Heater Design Tables
| P a g e 173
| P a g e 174
| P a g e 175
| P a g e 176