With the threat of snow and freezing temperatures looming, it is important to make sure your facility and heat-treating equipment are fully prepared to handle winter conditions. Since most of us have heat exchangers installed outdoors, it is essential to winterize the water system before outside temperatures drop to, or below, the freezing point.
Ethylene glycol, or antifreeze, is often preferred for use in vacuum furnace water systems because it is compatible with steel, copper and most other materials used in the system. For states with strict regulations on the use of ethylene glycol, possible alternatives are propylene glycol or refrigeration-grade antifreeze. Regardless of your choice in antifreeze, you must use a sufficient concentration for protection against your lowest expected ambient temperature. The concentration used is predicated on your geographic location and expected weather conditions.
In addition, capacity dampers and pan heaters are required for operation in below-freezing temperatures. One alternative to electrical pan heaters is a gravity-return, or self-draining tank system.
Once the winter season ends, it is also important to verify that the concentration of antifreeze in the water system is not too high since the heat rejection rate changes for an ethylene glycol solution and could possibly hinder cooling rates in warmer months (though this is also dependent on the geographic location). As the weather gets warmer, a 30-40% concentration is generally adequate for proper furnace and ancillary equipment protection. Another alternative is to charge the heat exchanger for year-round service with ethylene glycol.
Preparing your water system for extreme weather conditions is just one aspect of properly maintaining your vacuum equipment so it can continue to operate at peak performance. If you require further information or assistance, please call Ipsen Customer Service at 1-844-GO-IPSEN (Toll Free: 1-844-464-7736; International: +1-815-332-2530).
Read more about essential preparations for winter shutdowns.