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Description of the machine
3.2
Operating principle
The machine consists of a cooling unit and a hydraulic
unit. The cooling unit cools the water in the insulating
tank, thanks to an evaporator (A) immersed in the tank
itself.
The water in the insulating tank acts merely as a means
of heat exchange between the coils and the evaporator.
The evaporator is cooled until its temperature is lower
than zero, so a layer of ice (the "ice bank") then forms
around it; this is in practice a cold reserve, to be used
when consumption levels increase.
The thickness of the ice bank is controlled by an electronic
thermostat (B) which starts and stops the compressor (C)
as necessary.
The thermostat has a 4-minute delay to allow the pressure
levels in the cooling circuit to even out after a brief electricity
supply failure. This means that, when the machine is switched
on, the compressor will start up about 4 minutes later. The
compressor will not start up if the tank is empty.
The coils (that the water and syrups pass through) are
immersed in the water in the tank.
The water in the tank is always kept moving thanks to a
stirrer (D); this facilitates the heat exchange between the
coils and the ice bank.
The water and syrups pass through different coils, and
never come into contact with each other inside the
machine: the mixing of water and syrups takes place in
the spout of the dispensing valve.
The syrup is contained in a bag-in-box, or in steel kegs
(outside the machine).
The condenser (E) eliminates the heat taken from the
water and generated by the compressor motor. For more
effective heat dispersal, the condenser has a cooling fan
unit.
It is important not to obstruct the condenser surface, and
regularly inspect it for dirt so it can always function well (see
6.7 - "Cleaning the condenser").
POLO 20-30-50/L POST-MIX
A
B
E
D
PL0040
PL0030
C
PL0050
13
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