Johnson Controls SABROE SAB 120 E, Руководство по эксплуатации

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Operating manual - SAB 120-151 A-frame (including ATEX)
008668 en 2019.08
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Operating instructions
Fig. 14: Shaft rotation
Compressor rotation is clockwise when facing the end of the compressor drive shaft.
The compressor should never be operated in reverse rotation as bearing damage will
result.
6.7 Compressor lubrication system
The compressor is designed specifically for operation without oil pump for high-stage service.
Boosters and some low-differential pressure applications require the demand pump option.
The lubrication system on the screw compressor unit performs several functions:
• It lubricates the rotor contact area, allowing the male rotor to drive the female rotor on a
cushioning film of oil.
• It provides lubrication of the bearings and shaft seal.
• It serves to remove the heat of compression from the gas, keeping discharge tempera-
tures low and minimising refrigerant or oil breakdown.
• It fills gas leakage paths between or around the rotors with oil, thus greatly reducing gas
leakage and maintaining good compressor performance even at high compression ratios.
• It provides oil pressure for development of balance load on the balance pistons to reduce
bearing loading and increase bearing life.
6.8 No pump oil system
The screw compressor unit is designed to be self-lubricating. Oil supplied to the compressor from
the oil separator is at system head pressure. In the compressor, oil from all lubricating points is
returned to a point in the compressor body where the pressure is lower than the compressor dis-
charge pressure. During normal compressor operation, the compressor unit essentially operates
as its own oil pump. All oil entering the compressor is moved by the compressor rotors out the
compressor outlet and back to the oil separator.
For normal high-stage operation an oil pump is not required.
6.9 Demand pump oil system
This system is designed to provide adequate compressor lubrication for some high-stage applica-
tions that operate with low differential pressures across the compressor suction and discharge
sides and all booster applications.
During the period from start-up to normal operation, the oil pressure alarm and oil pressure cut-
out set points will vary according to formulas built into the microprocessor control program.
COMPRESSOR