Technique for evaporating and recycling wastewater generated in hydroxypropyl methyl cellulose production

Abstract

The invention discloses a technology for evaporating waste water from hydroxypropyl methylcellulose production, which has a first-effect evaporation device, a second-effect evaporation device, a three-effect evaporation device, a second-effect separation device and a three-effect separation device, and is characterized in that: The wastewater from the first-effect evaporator is evaporated by primary steam heating; the steam generated from the wastewater from the first-effect evaporator is used as the heat source of the second-effect evaporator to further evaporate the wastewater from the second-effect evaporator; the steam generated from the wastewater from the second-effect evaporator is used as the third-effect evaporation The heat source of the device; under the condition of negative pressure extraction, the wastewater in the three-effect evaporation device is vaporized at about 80°C, and after condensation, it enters the biochemical treatment system for further treatment. The second-effect evaporator and the third-effect evaporator are equipped with separation devices, and the waste water containing crystalline salt is separated from solid and liquid by the second-effect separation device and the third-effect separation device at any time, the solid salt is recovered and treated, and the liquid waste water is returned to the third-effect evaporator for recrystallization . The recovered hot water is reused for production through three-effect evaporation.

Description

technical field [0001] The invention belongs to the field of fine chemical production, and relates to a technology for treating wastewater produced by hydroxypropyl methylcellulose, in particular to a technology for evaporating and recycling wastewater produced by hydroxypropylmethylcellulose. Background technique [0002] Most of the hydroxypropyl methylcellulose production wastewater of similar domestic enterprises adopts the biochemical treatment method of using activated sludge after dosing and flocculation. Because this part of the wastewater contains a certain amount of salt, the effect of dosing and flocculation is poor and the biochemical treatment is difficult. . At the same time, this part of the wastewater has a high temperature and does not contain calcium and magnesium ions that produce hardness. Direct discharge wastes heat and water resources. The wastewater is suitable for the production of hydroxypropyl methylcellulose after evaporation of salt. Contents o...

AI Technical Summary

Problems solved by technology

According to the characteristics of high temperature and no hardness of the wastewater, the "Wastewater Three-Effect Evaporation Hot Water Reuse" device has been developed specifically. Through the three-effect evaporation, the recovered hot water can be reused in production, and at the same time, it solves the need for a large number of waste water in production. The problem of hardness hot water and the problem of environmental protection treatment of this part of wastewater

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