Saving Water with Glycol Chillers
At our distillery, we decided to forgo using municipal water for cooling because of the cost. Instead, like a true laboratory, we opted for circulating chillers. Our electricity in upstate New York is affordable, so we only pay for instead of the additional water expenses.
Benchtop circulating chillers are plentiful finds from laboratory surplus and Ebay. They usually have a heating coil and a refrigeration compressor onboard, and some type of temperature control, usually digital. We are only interested in cooling for our work to supply coolant to the condensers, traps, and reflux heads.
Our favorite unit is the Lauda-Brinkman WKL230. We have 5 of them in use, and this unit will reliably run to -8’C using propylene glycol as a coolant. Some of our units will drop to -10’C. These units also feature a nice round access port which is also handy for inserting a glass inline trap. The circulation pumps will bring the coolant up a 48″ vertical line. $200-$500 is a fair price if they are cooling. If they are not working, sometimes a simple fuse or just adding coolant brings them back fast.
Our second favorite is the Thermotek T252 series solid-state chiller. This is an electric Peltier cooler, rather than a gas refrigeration chiller. These units will cool to about +4’C and will pump about 36″ high. These are great for a secondary condenser. $100-$400 is a fair price if they are cooling. If they are not cooling, the repair is extensive and frustrating.
The Lauda WKL230 at -7’C and the Thermotek T252 at +4’C during a run.
A Lauda in use as a cold trap for a vacuum line at -9.7’C.
We can even go colder on 110VAC! Lauda also makes flow-through coolers, which will drop the coolant output from a WLK230 down to -30’C. You need a primary unit to pump the coolant into this, as there is not a circulating pump onboard. Special coolant is needed, and this unit has a very special left-hand threaded hose connection. Insulation is a must the whole length of the inlet and outlet lines.
Finally, a cooler with a bit more powerful pump and larger reservoir is useful for our big condenser on our 100L glass pot still. We opted for a Lauda K-2/R, which works well for us. This is also a 110VAC unit and will cool to around -4’C. It is ancient and heavy, but it is a solid workhorse and worth it if you find one working. Be VERY careful not to break the glass thermometer unit on the bath, which has an electrical connection to the temperature control.
Stay frosty!