Page 48 - 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 Title
Job No. Charge No. Date
Based Upon Cost Est:imate Dated or Actual Construction Cost
Summary Prepared By Information Dated
Production Basis (lbs./day, tonstday, lbs./month)
Unit Rate,’
- Service RequirementA: Unit Rate Production BasLA
1. Steam (30 lbs,,) lbs ./hr .
2. Steam (150 lbs.) lbs. /hr .
lbs ./hr..
3. Steam (400 lbri.) lbs . /hr .
4. Steam ( lbrr.)
5. Treated R.W. gPm
6. Untreated R.W. gpm
7. Fresh Water gPm
8. Sea Water gem
9. Fuel Gas ( psi) cfm (600F & 1 atm.)
io. Ais psi:) cfm (60°F & 1 atm.)
11 * Power ( )
12. Horsepower
13. Condensate lbs ./hr.
14.
- Unit Rate
Raw Materials:
1.. Chlorine
2,, Hydrogen ( %)
3,) Caustic (, s.)
4,. Salt
5,, Sat. Brine
6,, Natural Gas
7., Air
8,, Ethylene
9 I*
lo 0
11 ,b
- Unit Rate
Products and By-products:
1. Chlorine
2. WCl ( %)
3. Salt ( %)
4. Caustic ( %)
5. Auunonia ( %)
6. X)
a. )
8.
9.
10.
Ib.

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 18 psig or 25 psig for all
design pressure of PO 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 a ves-
normally be designled for 2 to 3 oz. of water. (See previous sel will be influenced by the fact that the minimum vessel
listing of API code:$ and ASME codes.) The bottom shell wall thickness for carbon steel is usually % inch to Yi inch.
of a LBO’ diameter x 40‘ tall vessel must withstand the Economics of the situation dictate where the cutoff pres-
greater pressure 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 pig, a reasonable design pressure Vessels operating below atmospheric pressure are
might be 10 psig. designed for full vacuum regardless of the actual vacuum.