FLOW-SHEETING
• What we will cover here?
1)
2)
3)
4)
PFD?
Preparation and presentation of PFD
P&ID?
Preparation and presentation of P&ID
FLOW-SHEETING
1) PFD?
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A shorter version of process flow diagram
A key document of process design
Shows the arrangement of the equipment, the
streams connection, streams flow rates and
composition and the operating conditions.
Diagrammatic model of the process
FLOW-SHEETING
1) PFD?
- Used as the basis for the next steps in the
design, including piping, instrumentation,
equipment design and plant layout.
- Drawn up from material balances made over
the complete process and each individual
unit operation.
FLOW-SHEETING
1) PFD?
- Most calculations on PFD are carried out
using commercial process simulation
software.
FLOW-SHEETING
1) FIG 4.1
FLOW-SHEETING
1) FIG 4.2
FLOW-SHEETING
2) PFD Preparation and Presentation
Essential Infos:
a) Stream composition, either
- Flow rate of individual component (kg/h) or as
weight fraction
b) Total stream flow rate, kg/h
c) Stream temperature (oC)
d) Stream pressure
- Fig 4.1/ 4.2A (with some modification): What I
expect in your design project.
FLOW-SHEETING
2) PFD Preparation and Presentation
Layout
- Sequence of the main equipment items shown
symbolically on the PFD follows that of the
proposed plant layout.
- Some license must be exercised in the placing
of ancillary items, such as heat exchangers
and pump, or the layout will be too
congested
FLOW-SHEETING
2) PFD Preparation and Presentation
Layout
- The equipment should be drawn approximately
to the scale.
- Should be drawn in correct proportion.
- Ancillary items can be drawn out of proportion.
- For a complex process, several sheets may be
needed, and the continuation of the process
streams from one sheet to another must be
clearly shown.
FLOW-SHEETING
2) PFD Preparation and Presentation
Layout
- Fig 4.2 shows one method indicating a line
continuation.
- Table of stream flows and other data (T, P)
can be placed above/ below the layout. (Fig
4.2)
- The stream line numbers should follow
consecutively from left to right of the layout
FLOW-SHEETING
2) PFD Preparation and Presentation
Layout
- All the process streams should be numbered.
Batch Process
- Normally show the quantity required to produce one
batch.
- If, a batch process forms part of an otherwise
continuous process, it can be shown on the same flow
sheet, providing a clear break is made when
tabulating the data between the continuous and
batch sections. i.e., the change from kg/h to kg/
batch.
FLOW-SHEETING
2) PFD Preparation and Presentation
Batch Process
- In a case where a batch process included in a
continuous process, the flow usually labelled
as ‘Normally no flow’, and show the flow
rates that will be obtained when the stream
is flowing.
FLOW-SHEETING
2) PFD Preparation and Presentation
Utilities.
- Usually only headers and lines were shown in
the process flow sheet.
Equipment Identification
-Must be identified with a code number a name.
H-xxxx (Heat exchanger), R-xxxx (Reactor), Cxxxx (Column).
FLOW-SHEETING
• What we will cover here?
1)
2)
3)
4)
PFD?
Preparation and presentation of PFD
P&ID?
Preparation and presentation of P&ID
FLOW-SHEETING
3) The P and I Diagram
- Shows the arrangement of the process
equipment, piping, pumps, instruments,
valves and other fittings, It should includes;
a) All process equipment identified by an
equipment number. Should be drawn roughly
in proportion, and the location of the nozzles
shown.
FLOW-SHEETING
b) All pipes, identified by line number. The pipe
size and material of construction should be
shown. The material may be included as part
of line identification number.
c) All valves, control and block valves, with an
identification number. The type and size
should be shown. The type may be shown by
the symbol.
FLOW-SHEETING
d) Pumps, identified by a suitable code number
e) All control loops and instruments, with an
identification number.
f) Process information is not shown.