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5.3 REFRIGERATION COMPRESSOR
The refrigeration compressor is the pump of the system where the gas coming from the evaporator (low pressure side) is compressed up
to the condensation pressure (high pressure side). The compressors utilized are manufactured by primary companies and are designed
for applications where high compression ratios and wide temperature changes are present.
The fully sealed construction is perfectly gas tight, so ensuring high-energy efficiency and long useful life. Dumping springs supports the
pumping unit, in order to consistently reduce the acoustic emission and the vibration diffusion.
The electric motor is cooled by the aspirated refrigerating gas, which goes through the coils before reaching the compression cylinders.
The thermal protection protects the compressor from over heating and over currents. The protection is automatically restored as soon as
the nominal temperature conditions are reached.
5.4 CONDENSER UNIT
The condenser is the element in which the gas coming from the compressor is cooled down and condensed becoming a liquid.
Mechanically, a copper tubing circuit (with the gas flowing inside) forms it immersed in an aluminum fin package. The cooling operation
occurs via a high efficiency fan, which, in applying pressure on the air contained within the dryer, forces it into the fin package. It’s
mandatory that the temperature of the ambient air will not exceed the nominal values. It is also important
TO KEEP THE UNIT FREE
FORM DUST AND OTHER IMPURITIES
.
5.5 FILTER DRIER
Traces of humidity and slag can accumulate inside the refrigeration circuit, or long periods of use can produce sludge, could limit the
lubrication of the compressor and clog the expansion valve or capillary tube.
The function of the filter drier, located before the capillary tubing, is to stop the impurities, avoiding their circulation within the system.
5.6 CAPILLARY TUBE
It consists of a piece of reduced cross section copper tubing located between the condenser and the evaporator and acts as a metering
device to reduce the pressure of the refrigerant. Reduction of pressure is a function of the temperature to be reached within the
evaporator: the smaller the capillary tube outlet pressure, the lower the evaporation temperature.
The length and interior diameter of the capillary tubing is accurately sized with the performance to be reached by the dryer; no
maintenance or adjustment is necessary.
5.7 EVAPORATOR
Also called an air-refrigerant exchanger. The liquid refrigerant formed in the condenser is evaporated in this part of the circuit. In the
evaporation phase the refrigerant side of the evaporator tends to absorb heat from the compressed air present in the other side of the
exchanger. The evaporator is immersed in the cabinet base of the dryer and insulated with non-CFC expanded insulating foam. The part
is entirely constructed in copper and the cooler goes in the opposite direction to the air, thus contributing to limited pressure loss and to
provide efficient thermal exchange.
5.8 HOT GAS BY-PASS SOLENOID VALVE
This valve is located between the pressure side of the compressor and the terminal side of the evaporator.
Its purpose is to avoid conditions of low thermal charge in the dryer (low air flow or relatively cold air)
The temperature inside the evaporators will drop below 32ºF. Temperature below 32ºF would eventually allow the formation of ice inside
the evaporator, with the consequent blockage of air flow and, in the worst of the cases, the rupture of the evaporator itself. The DMC11
Controller activates the coil of the solenoid valve.
5.9 AIR-TO-AIR EXCHANGER
The purpose of this exchanger is the transmission of the heat of the incoming air to the exiting cold air. The benefits of this solution are
basically twofold: the incoming air is partially cooled down. Therefore the chilling system can be sized for a lower thermal drop, thus
allowing a 40-50% energy saving; moreover, cool air will never reach the compressed air circuit and condensate will not form on the
external surface of the piping.