Page 17 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

6 Applied Process Design for Chemical and Petrochemical Plants

LOW AND MEDIUM GRADE PHOSPHATE ORES

RAIL
r GRIZZLY

Figure 1-5B. Isometric pictorial flow diagram. By permission, J. W.
Keating and R. D. Geckler, Aerojet General Corp.

These are quite valuable and time saving during the engi-
neering of the project. They also identify the exact flow
direction and sequence of tie-in relationships for the
operating and maintenance personnel.

6. Special Flowsheets or Diagrams

From the basic process-containing flowsheet other
engineering specialties develop their own details. For
example, the instrument engineer often takes the
requirements of the process and prepares a completely
detailed flowsheet which defines every action of the
instruments, control valves, switches, alarm horns, signal
lights, etc. This is his detailed working tool.
The electrical engineer likewise takes basic process and
plant layout requirements and translates them into details
for the entire electrical performance of the plant. This
will include the electrical requirements of the instrumen-
tation in many cases, but if not, they must be coordinated.
O’Donnell [9] has described the engineering aspects
of these special flowsheets.

Figure 1 -5A. Pictorial sections flow diagram for principal operations: 7. Special or Supplemental Aids
phosphate recovery. By permission, Deco Trefoil, 1958, Denver
Equipment Co. (a) Plot Plans, Figure 1-14
Plot plans are necessary for the proper development of
5. Utility Flowsheets m Diagrams, Figures 1-12 and 1-13 a final and finished process, piping or utility flowsheet.
After broad or overall layout decisions are made, the
detailed layout of each processing area is not only helpful
Used to summarize and detail the interrelationship of but necessary in determining the first realistic estimate of
utilities such as air, water (various types), steam (various the routing, lengths and sequence of piping. This is
types), heat transfer mediums such as Dowtherm, process important in such specifications as pipe sizing, and pump
vents and purges, safety relief blow-down, etc., to the basic head and compressor discharge pressures. The nature of
process. The amount of detail is often too great to com- the fluids-whether hazardous, toxic, etc.,-as well as the
bine on other sheets, so separate sheets are prepared. direction or location or availability for entrance to the