Acetylene sodium hypochlorite cleaning waste liquid circulating zero-discharge system for a PVC production process

Abstract

The invention discloses an acetylene sodium hypochlorite cleaning waste liquid circulating zero-discharge system for a PVC production process. The system comprises a cleaning tower system, a dilute sodium hypochlorite preparation system, a waste sodium hypochlorite water purification system, a triple-effect evaporation desalting device and the like, wherein the cleaning tower system comprises an empty tower, a cooler, a water washing tower, a cleaning tower I, a cleaning tower II and a neutralizing tower, the empty tower, the cooler, the water washing tower, the cleaning tower I, the cleaningtower II and the neutralizing tower are sequentially connected, the dilute sodium hypochlorite preparation system comprises a hydrochloric acid storage tank, a storage tank I, a high-position tank anda storage tank II, the storage tank I, the high-position tank and the storage tank II are sequentially connected, the waste sodium hypochlorite water purification system comprises a water collectingpool, a stripping tower, a quartz sand filter, a ceramic filter, a clear water pool, an ultrafiltration device and a reverse osmosis device, and the water collecting pool, the stripping tower, the quartz sand filter, the ceramic filter, the clear water pool, the ultrafiltration device and the reverse osmosis device are sequentially connected. According to the invention, with the system, the problems of poor cleaning effect, scaling of the clean tower, calcium salt enriching, high waste sodium hypochlorite content, high-salinity wastewater discharge and the like in the prior art are solved.

Description

technical field [0001] The invention belongs to the technical field of chemical equipment, in particular to an acetylene sodium hypochlorite cleaning waste liquid circulation zero discharge system used in the PVC production process. Background technique [0002] There are two cleaning processes for acetylene gas in the production of PVC by the calcium carbide method, sulfuric acid cleaning and sodium hypochlorite cleaning. Sodium hypochlorite is used for purification, and there is a large amount of salty and phosphorus-containing wastewater that needs to be treated. If the waste sodium hypochlorite is recycled, a large amount of salts will be enriched, and phosphate, carbonate and calcium salt will form precipitates, which will be precipitated on the clean packing, affecting the cleaning effect and causing the system to stop for processing and precipitation; at the same time, the organic matter in the waste sodium hypochlorite will be enriched, Affect the cleaning effect, ca...

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Problems solved by technology

[0006] In order to overcome the above-mentioned shortcoming of the prior art, the object of the present invention is to provide a kind of acetylene sodium hypochlorite cleaning waste liquid circulation zero discharge system used in PVC production process, in order to solve the above-mentioned poor cleaning effect, cleaning tower fouling, calcium salt enrichment , waste sodium hypochlorite content is too high, high-salt wastewater discharge and many other problems

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