indyspirits Posted July 28, 2017 Share Posted July 28, 2017 For those w/ closed loop chiller systems, how are you controlling flow to your dephlegmator? Are you controlling flow on the input side or the output side? Link to comment Share on other sites More sharing options...
Natrat Posted July 29, 2017 Share Posted July 29, 2017 always control input. output to drain should be open to prevent expansion, gas formation, or vacuum issues in the dephleg. Use preheated coolant from your condenser, as it will always be cooler than your dephleg, and it will be easier to control without stalling the head of the column from too much cooling. A pair of solenoid valves shunting water from condenser drain to dephleg works well, controlled by a PID on the water temp on your dephleg. If the can doesn't have a port or thermowell for your RTD, then you can use a T on your output drain and measure off of that. I have lots of diagrams :-) Link to comment Share on other sites More sharing options...
indyspirits Posted July 30, 2017 Author Share Posted July 30, 2017 12 hours ago, Natrat said: prevent expansion, gas formation, or vacuum issues in the dephleg Can you explain instances where the latter two could happen? I certainly understand how the glycol could expand. Link to comment Share on other sites More sharing options...
jweuaiaiai Posted December 23, 2020 Share Posted December 23, 2020 This problem should be improved now. I use a chiller made in Taiwan Built-in controller from Europe provides accurate and stable temperature control I want to know more about the situation you want to ask Link to comment Share on other sites More sharing options...
Southernhighlander Posted December 25, 2020 Share Posted December 25, 2020 On 7/30/2017 at 7:00 AM, indyspirits said: Can you explain instances where the latter two could happen? I certainly understand how the glycol could expand. Even though this was originally posted 3 years ago, I thought that I should reply. Natrat was correct. Always control flow from the input side not the output side. If you control a dephlegmator using a valve on the output side, you will also have a valve somewhere on the input side. Scenario number one, vacuum implosion: The run is completed and the input valve and output valve for the dephleg coolant are both closed causing vacuum to be created in the closed system between the closed coolant input and output control valves as the still cools, ultimately causing a critical failure resulting in a vacuum implosion of the dephleg. Vacuum caused by cooling in a closed system is a force of nature. Never underestimate it. This rail car was haveing a cold liquid pumped in with no vacuum relief:: Scenario number two, pressure explosion: The still's final condenser and dephlegmator are plumbed separately and the operator is doing a stripping run so he closes the coolant control input and output valves creating a closed system with cold coolant in the dephlegmator and lines so that as the still's temp increases, pressure increases in the dephlegmator causing it to explode, blowing out hot steam and possibly shrapnel. Never control a dephlegmator or final condenser's coolant flow with a valve on the output side. Link to comment Share on other sites More sharing options...
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