Water in the instrument air caused the unit to shut down
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It’s really frustrating – yesterday, due to water in the instrument air supply, the company’s emergency shutdown device caused the valve in the main instrument air line to freeze, which in turn led to the shutdown of the main fan’s safety system. It took two days and one night to get the system back under control; despite all the hard work, the company’s management wasn’t satisfied. I wonder if anyone has encountered this problem? How does your company address the issue of water in the air lines for instrument air?
The main thing is to carry out regular drainage of the buffer tanks for the instrument air compressors. More importantly, the drying system must operate stably and require regular drainage as well. The same applies to the instrument air buffer tanks; we encounter similar problems, and the responsibility lies in the fact that management does not pay enough attention to utility systems, and operators do not follow the prescribed procedures. Last edited by CHEN333 on 2008-12-22 at 20:20.]
Timely drainage and proper air drying are the most important things
Wow, the valve is frozen? It’s so squishy with this much moisture! The drying tower is operating normally; adding more buffer tanks to the main pipeline should not pose any major problems. Nothing of that kind has happened in our facility yet. Hehe, chemical plants in the north really have a tough time during winter!
We install a certain length of heat tracing on the air supply for the important unit control valves, and carry out cleaning of the valve diaphragms and similar components at the onset of winter.
During winter, the instrument air needs to be checked and drained frequently; in particular, before winter arrives, the pressure regulators, filters, and drain points should all be inspected and drained one by one； We request that some of the self-protection interlocks (low flow rate of main air, low flow rate of pressurizing air, low flow rate of raw materials, etc.) be temporarily removed, or that in future improvements to these self-protection interlocks multi-parameter voting mechanisms be adopted to reduce the likelihood of incorrect instrument operations.
The forum has discussed issues related to water in the instrument air supply, including purification methods; please look it up on your own!
Our company has also encountered the problem of instrument air containing water. First, when starting the vehicle, the instrument air contains a high amount of moisture and impurities; it is necessary to remove them first before opening the valves. A two-valve pressure reducing filter must be used, as it can play a certain role. 3. During major repairs, it is necessary to replace the desiccant inside the pressure reducing valve with a new one; this also includes replacing the overall desiccant used in the air separation system
Drain water at regular intervals, ensure proper air drying, and install air filters.
Install a compressed air water-removal tank and carry out regular cleaning of this tank. (It is simple and reliable; it can remove 99% of the water, but its effectiveness in removing oil is poor.) For higher-quality instrument air, a compressed air dryer is necessary (thermal or refrigeration type), which can also remove oil.
Dizzy! The gauge wind belt carries water; to find someone who works with gauges, one should turn to the wind pressure station.