Scotsman 600 Eclipse - Manual (Page 31)

Refrigeration Details:
The compressor provides the force that circulates
refrigerant in the refrigeration system. During
freeze, when the vapor inlet and condenser by
pass valves are closed, discharge gas flows from
the compressor into the condenser, where its heat
is discharged into the air stream. Liquid refrigerant
flows out of the condenser and through the
normally open liquid line outlet valve on its way to
the receiver inlet. Under low ambient/low pressure
conditions, the headmaster valve closes the liquid
outlet of the condenser and opens a bypass route
to direct refrigerant gas to the receiver inlet until
discharge pressure builds back up to the
headmaster’s set point.
From the receiver liquid outlet, liquid
refrigerant flows into the liquid line
and into the ice making section. At
the ice making section, the
refrigerant flows into the expansion
valves where a pressure change
takes place. The liquid refrigerant
moves from the expansion valves
into a low-pressure area (the
evaporators) where it can rapidly
evaporate and absorb heat. Heat is
absorbed from the copper
evaporator tubing, attached copper,
tin, plastic and the water flowing
over the evaporators. Check valves
prevent the evaporating refrigerant
from flowing into the wrong
evaporator. The low-pressure
refrigerant gas then flows into the
suction line, which carries it back to
the condensing unit, where it enters
the accumulator. In the accumulator
most of any liquid carried with the
suction gas is separated and only
vapor flows out of the accumulator
through the CPR valve and to the
compressor where the cycle
continues.
During harvest discharge gas flows
through the open condenser by
pass valve into the vapor line.
Power is also applied to the coil of
the liquid inlet valve, closing it. At
the same time, in the ice making
section, the vapor inlet valve opens.
Discharge gas, combined with some
vapor from the receiver’s outlet,
then flows through the vapor line to the evaporator
inlets. The gas-vapor combination, when entering
the relatively cold evaporators, condenses,
transferring latent heat to the evaporators, which
warms them. Ice releases and falls into the bin.
The low-pressure refrigerant then flows out of the
evaporators and into the suction line. The suction
line brings the refrigerant, now consisting of a
vapor-liquid combination, to the accumulator. From
the accumulator the vapor-liquid combination (now
more vapor than liquid) goes to the Crankcase
Pressure Regulator valve which limits the amount
of dome pressure in the compressor, where the
cycle continues.
Eclipse
ä 600, 800, 1000
April 2002
Page 31
Discharge
Line
Headmaster
Liquid Inlet
Valve (N.O.)
By-Pass Valve
TXVs
Vapor Inlet Valve
Check Valves
Evaporator
Receiver
Liquid
Line
CPR
Valve