15
5.10 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 clogging of the air port and, in the worst of the cases, the
rupture of the evaporator itself. The coil of the solenoid valve is piloted by the Air Dryer Controller.
5.11 5-MICRON FILTER
Positioned at the outlet of the aftercooler, the 5-micron filter ensures a good degree of purification of the treated air. The
filter unit is embodied in the container so as to ensure rapid and easy replacement.
5.12 AFTERCOOLER
The air aftercooler is the component where the hot air entering the dryer undergoes preliminary cooling down. It consists
of a circuit of copper tubing, supporting the circulation of compressed air, immersed in an aluminium body provided with
cooling blades. A high efficiency axial fan moving ambient air onto these blades provides the necessary cooling down of
the system. It is mandatory that the ambient temperature will not exceed the nominal value for the dryer. It is equally
important to
KEEP THIS SYSTEM FREE FROM DUST AND FOREIGN MATERIALS
eventually introduced
by the fan.
5.13 AIR/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 two: 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.
5.14 CONDENSATE SEPARATOR
The cold air exiting the evaporator goes through the "demister" type condensate separator featuring a stainless steel net.
As the condensate transported by the air gets in contact with the metallic net of the "demister" it is separated and expelled
by means of the draining device. The resulting cold and dry air is then conveyed into the air/air exchanger.
The "demister" type separator offers the benefit of being highly efficient, even with variable flow rates and do not require
special maintenance.
5.15 COOLING FLUID PRESSURE SWITCH PV (25 SCFM dryers only)
To safeguard a safety operation and the integrity of the dryer, a pressure controller has been installed on the refrigerating
gas circuit.
PV:
Condenser fan control switch located on the pushing side on the compressor keeps the condensation
temperature/pressure constant within preset limits.
Setting pressure : R 404A
Stop 232 psi/104ºF - Restart 290 psi/115ºF
