Analysis & Design of
Common Chemical
Engineering Systems
What is Analysis?

Analysis is the process of identifying a question
or issue to be addressed, modeling the issue,
investigating model results, interpreting the
results, and possibly making a recommendation.
Typical analysis for process
design may include:

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
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Market and Technical Feasibility
Choice of Technology (Proven, Innovative,
path/ rating)
Identification Process Equipment in the Plant
Choice of Design theme and mode
Availability of raw materials, utilities, human
resource and process constraints
Costs of providing the services, skills, materials,
equipment, taxes and other economic issues.
Invention and Design

INVENTION
An invention is something produced for the first
time through the use of imagination or
ingenious thinking and experimentation. A
famous quote is: "Necessity is the mother of
invention

DESIGN
Engineering Design is like an invention to
suit the unique demand of the customer
(customized solutions).
What is Design?

Design is the human power to conceive,
plan, and realize products that serve
human beings in the accomplishment of
any individual or collective purpose."

Process Design is the sizing of equipment
and facilities necessary to carry out the
process.
Engineering Design may require
(A). Design for new process
(B). Process design
(C). Mechanical design
(D). 3D design
(E). Fabrication
(A).
Design for New Processes
– What is the Design Process?
Typical five steps through which scientific
principles are applied for the solution of
Engineering problems are:
1.
2.
3.
4.
Define the Problem
Finding solutions and ideas
Documentation of ideas
Testing and Refining
5. Production
Defining the Problem
The design process is undertaken after a specific
problem or need has been identified. The
identification of the problem occurs in the
research and development stage of
manufacturing.
 Once scientists and engineers working in R&D
have identified the need for a product or
discovered a problem, the design process is used
to make the new product or solve the problem

The design process
The wagon...
Either fix the wheel
...broke
Or add tires so it doesn't brake again
Finding solutions and Ideas
In this phase, ideas are
examined and a concept
of the overall design is
developed.
 Preliminary sketches are
used to document the
design and/ or computer
software used for it.

One can document by hand or...
... use a CAD system
Documentation of Ideas
In this phase, all preliminary drawings
or sketches from the previous phase are
transformed into a finished package.
 Today, this is accomplished using
Computer Aided Drafting and Design
(CADD) systems.

To test, a computer simulation can be made ...
... and examined using virtual reality ....
... and a SLA/ CNC machine can be used to make a physical prototype.
Testing and Refining

In this phase, the design is tested in more
realistic modes. This usually involves pilot plants
and computer simulations for better
visualization.
Machining equipment is used to mass produce the final product.
Production


In the production phase, the
design is sent off to be produced.
With the use of a CADD system,
the data from the design is
translated into a form that a
Computer Aided Manufacturing
(CAM) system can understand.
Typical examples are CNC and
CIM. Some productions processes
involve Robotics as well.
(B).
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Process Design
Process design is the design of processes for desired
physical and/or chemical transformation of materials.
The deep understanding of physical, chemical,
thermodynamic properties in relation with working
conditions, separation phenomena, rates of reactions,
laws of transfer, transformation etc is desired.
The availability of technology and kind of machinery
and it’s range of applicability should be well
understood.
The overlapping areas of mechanical, electrical,
chemical, metallurgical and civil engineering need to
be well understood.
(C).

Mechanical Design
Using Drawing boards/CAD
(Horizontal Cylindrical Tank supported on compression load cell)
Conical Hopper
(D).
3D design
Drawing and Model
(E).

Fabrication
Fabrication is a specialized job jointly done by the
collaboration of Chemical, Mechanical and
Instrumentation engineers.
How to design
1). Mathematical
Model/Equations
2). Software
3). By Analogy
1). Using Mathematical
Model/Equations
(The continuity equation)
(Heat conduction equation)
(Bernoulli equation)
2).
Using Software
Design software can be categorized as :
1. Design and Draft
(e.g AutoCAD)
2. Modeling and Simulation
(Solid Edge, Hysys, AspinPlus, AspinDyn,PRO-II,
SuperChem)
3. Analysis Software
(Hysys, Asys, PRO-II)
Right software for right job !
Software Tools for Design
ASPIN PLUS
PIPECAD
HYSIS
SOLID EDGE
CONSYD
SOFTWARE
TOOLS
AUTOCAD
TUTSIM
MATLAB
AUTOPLANT
MATRIX-X
Characteristics of Drafting Softwares

Main capability is Drafting
(Generate Drawings, Fabrication & Assembly Diagrams)
Low 3-D capabilities
 Different Environments available in Software to
suit Mechanical, Civil, Architecture etc.
 Fabrication details can be provided such as

( Materials, welding, grinding, Tolerances and Surface Finish
information)
Characteristics of Modeling Software
Can generate drawings
 Can model a process for better
visualization
 Models can be used with other softwares
for further processing
 Can Generate machine code for fabrication

Model Visualization
Gasifier
Characteristics of Analysis Softwares
Requires most input from other software e. g.
Drawing/Model, Material Properties, Boundary Conditions
and other Computational constraints
 Elementary Analysis e.g. Assembly, Fixing and
Alignment, Collision, Force
 Working in layers
 Integration with other software
 Standard procedures need to be followed in the design

(Hysys, Fluent, Asys, Aspin etc)
3).
Scale up
By Analogy
Common Chemical Engineering Systems
Furnace
Heat
Exchanger
Auxiliaries
Ancillaries
Crystallizer
COMMON
Chemical
Engg.
systems
Distillation
Column
Filters
Boiler
Tanks
Vessels
Centrifuges
Reactor
Case Study
Design & Fabrication of a
Down Draft Gasifier Rig
Facility Developed at Chemical Engineering, UET
Downdraft
Gasifier
Wet
Scrubber
Blower
Water
Recirculation
Tank
Recycle
Pump