Heidolph Rotacool User Manual
Page 7
7
E
For temperatures under +10 °C, anti-freeze must be added to the coolant water.
Check the highest and lowest permissible temperature of the selected thermal fluid against
your desired operating temperature range.
For thermal fluids, please note the following:
Maximum operating temperature: The flash point of the thermofluid used
should be at least 5 K higher.
Minimum operating temperature: The viscosity of the thermofluid increases
at low temperatures. This impairs flow and reduces heat transfer. Viscosity
should therefore be as low as possible and should not exceed 120 mm²/s.
Remember that many thermofluids are hygroscopic. The air humidity to collect
in the thermofluid will form a layer of ice on the surface of the evaporator which
will impair heat transfer. At temperatures below room temperature in particular,
the filling apertures should be sealed with the cover (1). The water to
accumulate in the thermofluid must be evaporated off from time to time, if
necessary.
You may not use the following coolants, as they destroy stainless steel
material 1.4301:
Cooling liquids which contain additives such as ethers, esters and
amines (which are contained in some glycolenes)
Demineralized or distilled water
Mineral or sea water
No CaCl
2
Sols
The bath for the cooling liquid for the circulating chiller has a capacity of approx. 2 l.
6. Connecting tubes
Screw the connections for the cooling liquid (2) to the threaded sockets (3, 4) using an open-
ended, 19 mm spanner. To connect the condenser of the rotary evaporator to your circulating
chiller, you will need a tube with a nominal width of 7
– 8 mm for both the advance and the
return. Attach the connecting tube (24) for the flow liquid-tight onto the right threaded socket
(3) on the top of the unit. Connect the connecting tube (24) for the return flow with the left
threaded socket (4). Protect both tubes against inadvertent slippage using hose clamps. If
you want to work with advance temperatures in excess of 5 to 10 K either above or below the
ambient temperature, these connecting tubes must be thermally insulated as well.
To ensure the proper circulation of the cooling liquid, make sure there are
no kinks in the connecting tubes.