Page 47 - Applied Process Design for Chemical and Petrochemical Plants Volume I

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.