In a recent article that we presented on getting rid of water from your heat transfer system, we stressed the importance of venting off water as steam through the relief valves on the expansion tank. Anyone who has tried to do this quickly realizes that it is a slow and painful process, leading to costly downtime and lost production. As a result, maintenance managers and production personnel often need a safe and faster way to evacuate water from your system.
The first solution involves injecting Nitrogen into the expansion tank just below the thermal fluid level (perhaps through a sight glass connection). You should keep the tank well above 105°C / 221°F. If you can have an insulation jacket around the tank, even better. This combination will cause steam to bubble faster to the surface. After that is done, we recommend that you connect a vent line and pull a vacuum on the expansion tank using an air handler. The vent line should be connected to an International Bulk Container tote to catch the exiting condensate.
The second solution in our bag of tricks is the use of a fast-throughput vacuum dehydration unit. These units can be rented from your local equipment leasing store. The principle of operation is simple. The thermal fluid is pulled into the dehydration-filtration skid through a heater before it is heated to 71°C / 160°F. Afterward, the fluid flows into the vacuum chamber where it is thinned out creating a great deal of surface area. The atmospheric pressure is reduced causing water to boil off before it is removed. If the moisture content is considerably high, we recommend operating the unit at 25 inHg/12.28 psi. As the fluid is dehydrated, you can increase the vacuum level to pull out even more moisture.
We hope that these tips save you time and money while helping to rid your heat transfer system of water safely and economically. If you need technical support with your heat transfer fluids, feel free to call Relatherm Heat Transfer Fluids. We are always available to help.