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3.6
Liquid cooling
3.6.1 Requirements and recommendations
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Cooling channels inside the camera are made of aluminium. Only use cooling liquids and cooling
equipment that are compatible with aluminium (to prevent corrosion). If the cooling circuitry
contains more noble metals than aluminium, the usage of magnesium anodes can be considered
•
Always ensure that the cooling connectors and cooling hoses are properly fastened and free from
any leaks. Leaking cooling liquid can get in contact with the back of the camera and may in the
worst case enter the camera, thus breaking the camera
•
A mixture of pure water and inhibited glycol is recommended to avoid corrosion and algae growth
o
Pure water can be distilled, demineralised, de-ionised or reverse osmosis water
o
Never use pure water without inhibited glycol since this causes corrosion
o
Glycol must be inhibited (to avoid corrosion) and the glycol content in the mixture must
be at least 20 volume % (to prevent algae growth)
o
Ethylene glycol has better cooling performance than propylene-based glycol but is more
toxic
o
Modern industrial glycols contain inhibitors alongside a pH buffer and biocide to prevent
corrosion, algae growth and rust
o
Never mix different glycols
•
The cooling system must be properly flushed and cleaned before adding suitable inhibited glycol
and pure water mixture as well as when the mixture needs to be changed
•
Prevent any contamination of the cooling liquid and cooling circuitry
•
Cooling solution with temperature and flow rate monitoring and alarm feature is recommended
•
Regular maintenance intervals are needed to ensure proper operation (e.g. checking the condition
of filters and cooling liquid)
•
Never use automotive antifreeze liquids
•
The cooling connectors of the welding camera are designed for a cooling hose with an inner
diameter of 6 mm. Such hoses need approximately 30 ml of coolant for each meter. An additional
1 l of coolant is needed with the radiator solution (described in Section 3.6.2). If a recirculating
chiller is applied (Section 3.6.3), the amount of additional coolant depends on the chiller reservoir
volume
3.6.2 Radiator solution
Cavitar has made extensive empirical tests with active liquid cooling utilizing a radiator with fans and a
water pump. The cooling liquid is maintained in a temperature close to the ambient temperature at the
location of the radiator. Cavitar offers radiator cooling solution that is compatible with the aluminium
body of the welding camera.
Fig. 3.14 shows the results for the radiator solution with cables insulated and without camera insulation
(see Figs. 3.2, 3.3 and 3.6-3.8). Air temperature around the radiator was 24 °C and flow rate was 20 l/min.