Product Manual

2.7 Air dryer
Flow diagram
Compressed air circuit
Compressed air enters heat exchanger (1) and is cooled by the outgoing, cold, dried air. Water in
the incoming air starts to condense. The air then flows through heat exchanger/evaporator (2)
where the refrigerant evaporates, causing the air to be cooled further to close to the evaporating
temperature of the refrigerant. More water in the air condenses. The cold air then flows through
separator (3) where all the condensate is separated from the air.
The cold, dried air flows through heat exchanger (1) where it is warmed up by the incoming air.
The condensate is automatically drained by the electronic condensate drain (9).
Refrigerant circuit
Compressor (4) delivers hot, high-pressure refrigerant gas which flows through condenser (6)
where most of the refrigerant condenses.
The liquid flows through liquid refrigerant dryer/filter (7) to capillary tube (8). The refrigerant
leaves the capillary tube at evaporating pressure.
The refrigerant enters evaporator (2) where it withdraws heat from the compressed air by further
evaporation at constant pressure. The heated refrigerant leaves the evaporator and is sucked in
by the compressor.
The condenser (6) pressure must be kept as constant as possible to obtain stable operation. Fan
control switch (P) therefore stops and starts the condenser cooling fan. If, under partial or no
load, the evaporator (2) pressure drops to approximately 2.25 bar(e) (32.63 psig), the hot gas
bypass valve (5) opens and hot, high-pressure gas is fed to the evaporator circuit to prevent the
evaporator pressure from dropping any further.
Instruction book
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