What to do when the alkali slag line is used up
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What should be done when the alkali slag line is used up? Should steam be used for blowing, or air? Is there a better method?
Purge with steam or an inert gas. ——\"Manual for the Installation Design of Process Piping in Petrochemical Plants – Part 1: Design and Calculation\", 4th Edition, Chapter 10, Section 1: Purging/Scaling of Equipment and Piping
Should steam be blown into the alkali slag tank? Is there any corrosion on the top of the tank?
It’s better to push with water first, and then purge with nitrogen
Do you all use water pressure to push it? Here, our pipelines are quite long, so we haven’t used water pressure for that purpose
That’s basically how it is; the pipelines are quite long as well, and the use of water for pushing things forward works pretty well. In winter, it’s necessary to use air or nitrogen to push the water out promptly. As far as I know, at least 2 workshops operate in this way
This post was last edited by longziyun on 2018-11-20 at 19:45. After the alkali sludge pipeline is taken out of use, it should first be rinsed with hot water (50–70°C); this water can flow into the downstream alkali sludge tank. Once it is confirmed that there is no oil present, compressed air or nitrogen is used to blow the water in the pipeline into the downstream alkali sludge tank. To thoroughly clean the pipeline, steam cleaning is necessary. Before carrying out steam cleaning, the pipeline must be disconnected at the valve leading into the tank, as high-temperature steam entering the tank can damage the anti-corrosion coating on its inner walls. The pipeline is then cleaned with steam to remove any impurities adhering to its walls, and steam is allowed to escape from the cut-off point for more than 4 hours before the connection is reestablished. Finally, air or nitrogen is used to blow away any remaining condensed water in the pipeline into the alkali sludge tank, and the tank valve is closed; if necessary, a blind flange is installed to seal off the pipeline. As for whether nitrogen should be used for protection inside the pipeline, it can be decided based on the specific circumstances.