Refrigeration & Equipment Engineering

4. OIL DRAINING SYSTEM

OIL DRAINING SYSTEM

Aim: To drain oil from the refrigeration system.

Apparatus: Hand lever, wrench, bucket, cotton waste, etc.

Working principle: In the compressor adequate oil should be fed to the crank case. This oil splashes and mixes with the discharge gas. When the gas mixed with oil flows into the condenser an oil film is formed inside the condenser and decreases the heat transfer capacity. If there is no oil in the separator it feels rather hot during operation. When oil has been trapped in the separator it feels rather cooled. The discharge gas is sent to the condenser through the oil separator wherein almost all oil particles in the gas are isolated from the refrigerant and collected at the bottom of the oil separator. The collected oil from the oil separator should be drained periodically.

Procedure:

• Open the valve No.1 at the bottom of the oil separator for 3minutes.
• Open the valve No.6 to allow the oil to flow to the oil drum for 3 minutes.
• See the oil pressure gauge No.12 (should show 10 kg/cm² ).
• See the level of oil in the oil level glass column.
• Close the valve No.1 and 6 after observing the level of oil in the oil level glass column.
• Open the valve No.8 to relieve the gas from the oil drum to the liquid separator (Suction side).
• When the oil pressure gauge comes to 0 kg/cm² close the valve No.8.
• Open the valve No.4 and drain the oil collected at the bottom of the oil drum; into the buckets Placed below the oil drum.
• When the oil level in the gauge comes to bottom, close the valve No.4.
• Observe the other safety provisions provided in the system.