Material and insulation issues of pressure swing adsorption programmable control valves
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The company is a manufacturer of methanol from coal, and it is located in a very cold region where temperatures can drop to minus 40 degrees during the coldest months. Pressure swing adsorption is used for the decarburization and purification of coal gas. In such a cold environment, is there an effective solution for the seamless switching of over 200 programmable valves? What are the specific requirements regarding valve bodies and seals at such low temperatures? If it’s necessary to insulate the valves, what approach would be the best? I would appreciate any good suggestions; a reward of at least ten points will be given, thank you!
There are a few questions to clarify: do you use 8 kilograms of pressure or 20 kilograms of pressure for your operations? Is the valve pneumatic or hydraulic? Please confirm first.
Based on our experience, when the temperature is below 12–15 degrees, the valves operate more slowly, fail to close properly, and the rods connecting them may break. A solution is to use insulation measures such as adding extra layers of material or using steam to keep the area warm, and this approach yields very good results.
Our two sets of PSA hydrogen production systems also have this problem; mainly, we use pneumatic valves, and the air supply is controlled by a five-way three-position slide valve. When the temperature drops, the sealing rubber inside the slide valve hardens, which causes the valve to get stuck. To address this issue, we moved the valves inside the building, and things are much better now. However, it’s important to ensure that there is sufficient ventilation in the room to prevent the concentration of hydrogen gas from becoming too high and posing a danger. We were the ones who carried out the construction for Sichuan Tianyi at that time.
Feed gas inlet pressure: 2.00 MPa (A); the valves are pneumatic and designed as a complete set by Tianyi. It is now recommended to build a factory building, which will cost over 1 million yuan. Given the current market conditions for methanol, it’s not easy to come up with 1 million yuan. Could the problem be solved by using electric heating for the valves? If PTFE (PTEE) or PEEK is used for the sealing rings, can this prevent them from becoming hard, brittle, and cracking at low temperatures?
The heat tracing effect is not good! It’s best to build a sealed house, as it provides good insulation! It’s best to solve the pneumatic valve issue in this way
When repairing a house, one issue is poor ventilation; another issue, as the original poster mentioned, is the high initial cost. Personally, I think there should be no problem with using heat tracing. If the original poster isn’t in a hurry to drive, it would be a good time to conduct a test during this season. . . . How can you know if it works without giving it a try? This post was last edited by chc1125 on 2009-1-4 at 10:16.]
For valve sealing, a hard seal is the preferred choice. It is advisable to install a drying and buffering tank for the instrument air supply; if necessary, insulate and heat the main air supply pipes to prevent freezing caused by excessive moisture in the air. If the process medium tends to freeze at low temperatures, it is important to provide proper insulation and heating to ensure that the valves can operate without sticking.
What you’re referring to is a design issue, right? We have installed many such devices in the north, and these factors need to be taken into consideration when selecting valves. Moreover, the sealing gaskets of these valves are not made of rubber, but rather of polymer materials