How to reduce the final cooling resistance
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Our factory is a coking plant with an annual production capacity of 10,000 tons of crude benzene. The final cooling device used is of the tubular heat exchange type. It has been in use for about 4 years now; since the beginning of 2008, the resistance in the final cooling system has increased at a very rapid pace – it rose from 300 Pa to 4,000 Pa within just one week. A large amount of sediment, scale, and similar substances have accumulated inside the heat exchange tubes, while the outer walls of these tubes show corrosion spots of varying sizes. Spraying hot ammonia water has had little effect； It was cleaned using cleaning oil, and at first the effect was good – the resistance of 4000 Pa could be reduced to 300 Pa. After several cleanings, however, the effect became much worse; now it’s only possible to reduce the resistance to 1500 Pa. May I ask the experts what causes this phenomenon and how can it be resolved? Thank you! :) :) :)
Dude, I’ve never seen this phenomenon. However, please check the circulation and spraying effect of light tar in the primary cooling system. I think the key is still to remove naphthalene.
Personally, I consider this issue from two aspects: 1. The clogging problem, which may be caused by naphthalene; it is necessary to increase the efforts and frequency of removing naphthalene. 2. Does the equipment need to be modified?
1. The dirt on the inner wall is caused by circulating water; the silt should be cleaned regularly. 2. Scaling on the inner wall affects heat exchange efficiency, resulting in increased resistance. It is best to pickle the inner wall.