Energy
Calculator for Atlas Copco Variable Speed Drive
1.
COMP. RPM = motor pulley p.d. x motor r.p.m comp.
pulley p.d.
2.
MOTOR PULLEY p.d. = comp. pulley p.d. x comp. r.p.m.
motor r.p.m.
3.
COMP. PULLEY p.d. = motor pulley p.d. x motor r.p.m.
comp. r.p.m.
4.
MOTOR RPM = comp. pulley p.d. x comp. r.p.m.
motor pulley p.d.
5.
FREE AIR = piston displacement x volumetric eff (%)
6.
REQUIRED PISTON DISCPLACEMENT = free air
vol. eff.
7.
PISTON DISPLACEMENT IN CU FT MIN =
cyl.
bore in In. x cyl. bore x stroke in IN. x r.p.m.
2200
Note: Piston displacement for multi stage compressors - only the
low pressure cylinders are considered
8.
CU. FT. COMPRESSED AIR = c.u. ft. free air x 14.7
(psig + 14.7)
9.
CU. FT. FREE AIR = cu. ft. compressed air x (psig + 14.7)
14.7
10.
CU. FT. FREE AIR REQ’D TO RAISE REC. FROM 0 GAGE TO
FINAL PRESSURE =
vol. of rec. in cu. ft x psig
(atmopheric pressure) psia
11.
CU. FT. FREE AIR REQ’D TO RAISE REC FROM SOME PRESS. GREATER THAN 0
GAGE TO FINAL HIGHER PRESSURE = vol. of rec in cu ft x (final psig
- initial psig)
(atmopheric pressure) psia
12.
PISTON SPEED IN FT PER MIN. = 2 x stroke (in inches) x r.p.m.
12
13. GALLONS = C.U. FT
0.134
14.
CU. FT. = Gallons x 0.134
15.
TOTAL FORCE IN LBS. of Air CYLINDER = Area of the cylinder dia. in square
inches x psig of air pressure used
16.
C.F.M. OF FREE AIR REQ’D TO OPERATE AIR CYLINDER (SINGLE ACTING) =
Vol. of Cyl. in cu. ft x cycles per min. x (gage pressure psig +
14.7)
(14.7)
17.
PUMP UP TIME (MIN) =
V (tank size in gal.) x (final tank pressure - initial tank pressure)
7/48 x atmos. pressure (psia) x pump delivery
(c.f.m.)
