Chemical Engineering December 2016 - 82

* Interactions between items within
the plot
* Interactions between plots within
the site
* Interactions between the site and
its surroundings
The approach discussed here is a
formalized summary of the steps that
are typically taken by chemical engineers
on large or dangerous plants.
Less formal approaches are more
commonly used in practice, however,
for reasons of economy and practicality.
Critical examination in particular
is a resource-hungry exercise. n
Edited by Suzanne Shelley
Author
Seán Moran is managing director
of Expertise Ltd. (25 Warmbrook,
Wirksworth Derbyshire,
U.K.;
FIGURE 4. This site layout model, produced using CADWorx from Intergraph, shows piped, road and rail
links
* Steam, water, sewage disposal,
and other services, particularly
the terminal points relating to the
plot
* Raw material and product pipeline
terminals
* Sources of atmospheric pollution
that might affect the process
operators or maintenance
staff
d. The detailed process engineering
design, which contains:
* P&IDs indicating (with identification
codes) the process equipment
and instrument requirements
and showing the pipeline
connections
* PFDs showing the flows and
composition of each stream
* Line schedules giving each pipe
its size, specification and the
temperature and pressure conditions
*
Equipment schedules and drawings
providing the specification
of each item together with its
plant size, register number, critical
dimensions, process power
requirements, process and utility
nozzle connections and flows,
materials of construction, process
conditions, operation and
maintenance requirements
* Process design datasheets containing
the process design data,
philosophy and calculations and
indicating any process layout requirements
*
The results of the hazard and
76
operability studies of the process
design
* The drawing conceived in Steps
1-9
Step 19. Plot layout. Most of the
initial steps, particularly Step 4, and
6-9 are repeated in greater detail
and subjected to the site constraints
given in Step 18.
It is important that, in repeating
Step 6, there is good coordination
between the layout, process, operating,
piping, civil, structural and
mechanical disciplines. The piping
arrangement studies (repeat of Step
8) done here are discussed in more
detail in Ref. 12.
The hazard reassessment (Step
9) will be mainly concerned with internal
plant spacings, such as area
hazard classification zones and
control room and other plant building
positions. Inter-plot spacings are
considered in hazard assessment
of the site layout. The repeat of the
critical examination should (as well
as considering the aspects given in
Step 9) also see that standards, regulations
and site constraints on the
plot have not been violated.
Hazard assessment
Increasingly, regulatory authorities
will require a combined hazard assessment
of the site and plot layouts
after both have been tentatively finalized.
Some existing activities will be
required to submit hazard assessments.
These include the following:
Email:
sean.moran@expertiselimited.co.uk;
Phone: +44-1629826482).
He holds a Masters Degree
in Biochemical Engineering
from University College London,
and is a fellow of the Institution of
Chemical Engineers. Moran has
25 years of experience as a process plant designer,
commissioning engineer and troubleshooter. He has
published two books [12,16], and is presently working
on another book, entitled " An Applied Guide to Water
and Effluent Treatment Plant Design. "
References
1. Kern, R., Arrangements of process and storage vessels,
Chem. Eng., 84, 93, 1977.
2. Kern, R., How to manage plant design to obtain minimum
cost, Chem. Eng., 84, 130, 1977.
3. Kern, R., How to get the best process plant layouts for
pumps and compressors, Chem. Eng., 84, 131, 1977.
4. Kern, R., Layout arrangements for distillation columns,
Chem. Eng., 84, 153, 1977.
5. Kern, R., How to find the optimum layout for heat exchangers,
Chem. Eng., 84, 169, 1977.
6. Kern, R., Space requirements and layout for process
furnaces, Chem. Eng., 85, 117, 1978.
7. Kern, R. Arranging the housed chemical process plant,
Chem. Eng., 85, 123, 1978.
8. Kern, R., Instrument arrangements for ease of maintenance
and convenient operation. Chem. Eng., 85, 127,
1978.
9. Kern, R., Controlling the cost factors in plant design.
Chem. Eng., 85, 141, 1978.
10. Kern, R., How to arrange the plot plan for process
plants, Chem. Eng., 85, 191, 1978.
11. Green, D.W., and Perry, R.H., " Perry's Chemical Engineering
(8th Ed.). " New York: McGraw-Hill, 2007.
12. Moran, Sean, " Process Plant Layout, 2nd Ed. " Institution
of Chemical Engineers, Butterworth-Heinemann, 2016.
13. Kidam, K., and Hurme, M., Design as a contributor to
chemical process accidents, Journal of Loss Prevention
in the Process Industries, 25, 2012, pp. 655-666.
14. Mecklenburgh, J.C., " Process Plant Layout, " Halsted
Press, 1985.
15. The Mond Index, GDG Associates, 1985.
16. Moran, Sean, " An Applied Guide to Process and Plant
Design, " Butterworth-Heinemann. 2015.
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Chemical Engineering December 2016

Table of Contents for the Digital Edition of Chemical Engineering December 2016