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Operating manual for LT series cooling water heat exchanger
6.
Function
The heat exchanger is mainly composed of a cooling circuit and a cold fluid circuit. The
cooling circuit serves the purpose of collecting the heat to be extracted from the user or
at the tool. The heat gathered by the cooling fluid is dissipated in the environing air via
the cold fluid circuit.
Cooling fluid circuit:
The cooling fluid transportation in the cooling circuit occurs via a built-in cooling
centrifugal pump and constantly circulates between the cooling fluid vat and the user.
The cooling fluid releases the heat to be evacuated via an evaporator in the cooling
fluid vat.
The cooling fluid vat is composed of high-resistance PE plastic as serves the purpose
of collecting the cooling fluid required for the cooling circuit. (See section "Technical
data" for contents of the container)
The filling level of the cooling fluid vat can be measured from outside using the
integrated filling level display.
Cooling fluid pump:
A robust, multi-stage block pump is used for the recirculation of the cooling fluid
required for cooling.
The pump must be deaerated at the pump head before commissioning. A deaeration
tube which is closed with a red lid is attached to the pump head for this purpose. The lid
is to be removed before filling. Filling is done via the filling nozzle on the casing lid. If
the water level reaches the upper mark on the water level display, filling of the device is
complete.
Avoid dry running of the pump
Cold fluid circuit:
The cold fluid circuit functions with safety cooling fluid R407C (R134a for tropical
design). This cold fluid is not poisonous, non-flammable and non-explosive.
The cold fluid is propelled by the compressor and circulates in a closed circuit between
the evaporator and condenser. If collects the heat from the liquid to be cooled in the
evaporator and thereby changes its state from liquid to gaseous. The gaseous
overheated cold fluid is sucked up by the compressor and compressed. The
compression of the cold fluid increases the pressure and temperature in the cold circuit.
The collected heat including the compression heat is dissipated in the environing air in
the condenser, and the cold fluid condenses at constant pressure. The condensing
pressure is brutally dropped at the thermostatic expansion valve mounted between
condenser and evaporator, allowing liquid cold fluid to be injected to the evaporator.
The injecting cold fluid evaporates again in the evaporator by obtaining the necessary
evaporation energy through heat collected from the cooling fluid. This circular process
repeats as long as the compressor is switched on, or as long as the desired target
temperature set on the temperature controller is not reached.
