The compressor is hermetic-type , single stage(TR-G140C1~TR660C1) or two stage(TR-G710C1~ 1070C1) centrifugal compressor impeller increasing device are mounted in the casing and the increasing gears and lubricating system are contained in the gear case.
The impeller is made of aluminium alloy and is sufficiently anticorrosive and strong enough to withstand high-speed revolution. The blade profile is designed more efficiently from the viewpoint of hydrodynamics a three-dimensional curved profile which enables efficient machine operation over a wide range. The gears are contained in a double casing. The impeller shaft and the pinion are connected with a special coupling in a manner that the gear and pinion are always operated with ideal meshing which insures quiet operation.

The main motor a hermetic, double squirrel-cage induction motor are cooled by liquid refrigerant supplied from the condenser.
After cooling the rotor and stator by means of the latent heat of liquid refrigerant, refrigerant gas is returned to the evaporator.
Since the quantity of refrigerant to be circulated through the motor is originally fixed, no adjustment is required.
Motor wiring insulation is designed to withstand by adopting the special material in wire varnishing.

The economizer comprises two orifices and liquid seperating chamber. The liquid refrigerant draining from the condenser is reduced in pressure to the second stage impeller suction pressure by the first orifice and enter the liquid separating chamber. A specifically designed eliminator made of brass and capable of highly efficient liquid separating is provided in the liquid separating chamber. The eliminator eliminates the liquid from the refrigerant vapour produced by partial evaporation at the reduced pressure and the vapour is piped to the inlet of the second stage impeller.
The remaining liquid again reduced in pressure at the second orifice and then flows into the evaporator.
Use of economizer results in both and improved refrigerating effect and a lower compressor power consumption.

The evaporator is of the horizontal shell and tube type. THERMOEXCEL-EK, which have a good heat transmission efficiency, are used as the cooling tubes. Both ends of tubes are expanded in bellmouth form for the convenience of tube removal. The cooling tubes are supportted by supporting plates installed longitudinally. Above the tube nests there is provided an eliminator made of special steel, which has excellent demisting efficiency. Special construction has also been adopted at the bottom of the shell to enable the refrigerant liquid to be distributed evenly throughout all of the tube nest. Thus insuring good operating efficiency.

The condenser is divided in two by the partitioning plate. The right part is the condenser. The condenser has the same shell-and-tube structure as the evaporator. The THERMOEXCEL-CK, which have a good heat transmission efficiency are used as the cooling tubes. At the gas inlet part there is a baffle plate which prevents the superheated gas from coming into direct contact with the tube nests.
It also ensures uniform distribution longitudinally. The condensed liquid is lead to the evaporator through flushing nozzle arranged longitudinally.

Capacity control of this refrigerating machine is perfromed by opening and closing the inlet guide vanes which are installed at the compressor suction. The vanes are driven by a small control motor, function through the links and bevel gears. In the case of two stage compressor, hot gas bypass valve, direct driven by a control motor.

The lubrication system is for lubricating the plain bearings and thrust bearing supporting both the compressor and main motor shafts and also for lubricating gears, thereby assuring normal operation.
The lubricating oil which is pumped up and pressurized by the oil pump(provide in the oil tank and driven by the enclosed-type motor) goes inside the cooler. After oil pressure has been adjusted, the oil is supplied to each bearings.
In addition, the oil tank is provided with an oil heater which maintains constant oil temperature while the machine is shut down to prevent the refrigerant from excessively dissolving into the oil.

The purge unit is designed to purge out noncondensable gases from the machine to improve the refrigerant efficiency.
Principle of Purge System Operation:
The refrigerant gas containing noncondensed gas, which has been led from the top of the condenser into the purge chamber, is cooled by refrigerant running through the cooling jacket installed around the periphery of the shell, the condensed refrigerant return to the evaporator through the float valve installed on the bottom of the purge chamber. The noncondensed gas is separated and stored in the upper part of the purge chamber. Gradually the pressure of the noncondensed gas in the tank increases, and in-tank pressure reaches the condensing pressure as result. The pressure differential decreases to a certain value, the pressure switch is actuated and opens the solenoid valve automatically to purge out the noncondensed gas tn the tank to the atmosphere.

Refrigerant cleaner is provided to separate the lubricating oil from refrigerant liquid, and to minimize the consumption of the lubricating oil.
The separate lubricating oil is returned to the oil tank.
Refrigerant cleaner is composed of heat exchanger manual valve, check valve, strainer and piping.