What measures need to be taken after the steam insulation for the materials in the storage tank is turned off?
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Our irrigation facility has 1 storage tank for liquid caustic at 48%, 2 storage tanks for 1,4-butanediol, and 3 storage tanks for C12-14 alcohols. These tanks are normally kept warm using steam heating. The company’s utilities department announced that steam supply will be suspended for a period during the Spring Festival holiday. The temperature here in winter ranges from -4°C to 8°C. What safety measures should be taken to ensure the safe storage of these materials?
Is it possible to take time off while production is ongoing? If operations are suspended, all materials in the pipelines should be transferred back into the tanks, and heating can be reactivated once work resumes
How long will the shutdown last? If it’s short, just a few hours, then it’s possible to estimate how much the temperature will drop. By leaving enough margin in terms of temperature, no action may be needed, or external insulation measures can be employed as a buffer. If the shutdown is prolonged, it is generally necessary to empty the storage tank, or to carry out electrical heating modifications on the outside of the tank in advance; however, with still one week left, such modifications may not be completed in time.
Production will be suspended for a week during the holiday, and steam heating will also be stopped for a week
Well, then don’t think about anything else; start adjusting the production plan from now on to gradually empty the storage tanks. Once the steam has stopped, make sure to empty the steam pipes as well to prevent freezing and subsequent bursting of the pipes.
Production has stopped, but there is a large amount of material stored in the tanks (as stock), and it cannot be removed
After the steam supply is stopped, compressed air should be used to blow away the condensate water from the steam. It is advisable to remove the drain valve to prevent any remaining water from causing damage due to freezing. When steam is introduced, if the material crystallizes, it should be heated slowly to prevent the material at the lower level from melting and vaporizing as a result of rapid heating, while the material at the upper level remains unmelted, which could lead to cracking.
The last edit to this post was made by Suspected law-abiding citizen on 2023-1-18 at 09:16. In that case, the only options are to ensure proper external insulation and use supplementary heating methods. It’s worth checking whether another heat source can be found on site as a temporary alternative. If hot water can be used as a substitute, one could consider buying a small hot water boiler (the kind used in bathhouses). If hot water is sufficient, it’s also possible to obtain it directly from municipal supplies or power plants.