Page 182 - Chemical Process Equipment - Selection and Design

154 FLUID TRANSPORT EQUIPMENT

TABLE 7.7-( continued)
(b) Horizontal, One-Stage, Steam-Driven"
Diameter, Diameter,
Steam Air
Cylinder Cylinder, Displacement, Air Pressure,
(in.) (in.) Stroke (in.) (cuft/min) rPm (Ib/sq in.)
7 7; 6 106 350 80-100-125
8 8; 9 170 300 80-100-125
9 10 10 250 285 80-100-125
10 11 12 350 270 80-100-125
7 8; 6 136 350 40-60
8 10 9 245 300 40-75
9 11 10 31 2 285 40-75
10 13 12 495 270 40-75
8 12 9 350 300 20-45'
9 13 10 435 285 20-45'
10 15 12 660 270 20-50'
"All machines have piston-type steam valves.
110-lb steam necessary for maximum air pressure.
125-lb steam necessary for maximum air pressure.
(Worthington Corp.).
(c) Horizontal, Two-Stage, Belt-Driven
Diameter Cylinder (in.) Piston
Displacement
Low Pressure High Pressure Stroke (in.) rpm (cuft free air/min)
4 2; 4 500 28
6 2; 6 350 65
8 3: 8 300 133
10 4; 10 275 241
(Ingersoll-Rand Co.).

TABLE 7.8. Summary of Rotary Compressor Performance Data

Helical Spiral Straight Sliding Liquid
Screw Axial Lobes Vanes Liner
Configuration, 8 16
features (male x female) 4x6 2x4 2x2 Blades Sprockets
Max displacement (cfm) 20,000 13,000 30,000 6,000 13,000
Max diameter (in.) 25 16 18 33 48
Min diameter (in.) 4 6 10 5 12
Limiting tip speed (Mach) 0.30 0.1 2 0.05 0.05 0.06
Normal tip speed (Mach) 0.24 0.09 0.04 0.04 0.05
Max Lld, low pressure 1.62 2.50 2.50 3.00 1.1
Normal Lld, high pressure 1 .oo 1.50 1.50 2.00 1 .oo
Vfactor for volumetric efficiency 7 3 5 3 3
%factor for displacement 0.0612 0.133 0.27 0.046 0.071
Normal overall efficiency 75 70 68 72 50
Normal mech. eff. at &IO0 HP (%) 90 93 95 94 90
Normal compression ratio R, 21314 3 1.7 21314 5
Normal blank-off R, 6 5 5 7 9
Displacement form factor A, 0.462 1 .oo 2.00 0.345 0.535
(Evans, 1979).