Page 50 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Process Planning, Scheduling and Flowsheet Design 35

PROCESS ENGINEERING JOB ANALYSIS SUMMARY

Job No ·------------Charge No,---------Date --------
Based Upon Cost Estimate Da..ted or Actual Construction Cost
Sunmary Prepared BY------------- Information Dated--------
Production Basis (lbs,/day, tons/day, lbs,/month)--------�-------
Unit Rate/
Service Requirements: Unit Rate Production Basis
l. Steam (30 lbs.) lbs./hr.
2. Steam (150 lbs.) lbs./hr •.
3. Steam (400 lbs.) lbs./hr.
4. Steam ( lbs,) lbs./hr.
5. Treated R.W. gpm
6. Untreated R.W, gpm
7. Fresh Water gpm
8. Sea Water gpm
9. Fuel Gas ( psi) cfm (600F & 1 atm.)
10, Air ( psi) cfm (600F & 1 ai:m.)
11, Power ( )
12, Horsepower
13, Condensate _______ lbs./hr.
14.
Raw Materials: Unit Rate
1. Chlorine
2. Hydrogen ( %)
3. Caustic ( %)
4. Salt
5 .. Sat. Brine
6. Natural Gas
7. Air
8. Ethylene
9.
10,
11.

Products and By-Products: Unit Rate
l. Chlorine
2. HCl ( i'.)
3. Salt ( '7.)
4. Caustic ( i'.)
5. Aaunonia ( '7.)
6. H2SOZ ( %)
7. Gas
8.
9.
10.
11.
Figure 1-32. Process engineering job analysis summary.

feet in diameter which will operate under 6 oz. water In some low pressure processes it is good practice to set
might be designed for 12 oz. while arbitrarily selecting a a minimum design pressure of 10 psig or 25 psig for all
design pressure of 10 psig would be quite uneconomical. vessels operating below 5 psig and no larger in diameter
A 40-foot diameter tank for atmospheric storage would than 8 to 10 feet. The minimum design pressures for aves-
normally be designed for 2 to 3 oz. of water. (See previous sel will be influenced by the fact that the minimum vessel
listing of API codes and ASME codes.) The bottom shell wall thickness for carbon steel is usually 716 inch to X inch.
of a 40' diameter x 40' tall vessel must withstand the Economics of the situation dictate where the cutoff pres-
greater pressme of the height of water or process liquid sures and/or diameters lie, as these will vary with the type
when the vessel is full to the vents. For a 6-foot diameter of metal under consideration.
vessel operating at 3 psig, a reasonable design pressure Vessels operating below atmospheric pressure are
might be 10 psig. designed for full uacuurn. regardless of the actual vacuum.