A vacuum membrane distillation sewage treatment device capable of recovering heat

Abstract

The invention discloses a vacuum membrane distillation type sewage treatment device capable of recycling heat. The vacuum membrane distillation type sewage treatment device comprises a heating tank which is provided with a heater and used for heating sewage, wherein a sewage outlet of the heating tank is communicated with a sewage inlet of a membrane evaporator through a liquid circulating pump, and a sewage outlet of the membrane evaporator is communicated with a sewage backflow inlet of the heating tank; a refrigerant inlet and a refrigerant outlet of a heat pump condenser in the membrane evaporator are communicated with a refrigerant inlet and a refrigerant outlet of a heat pump evaporator through pipelines; and a steam inlet of the heat pump evaporator is communicated with a steam outlet of the membrane evaporator, a liquid water outlet of the heat pump evaporator is connected with a steam-water separator, and a gas outlet of the steam-water separator is connected with a circulating water vacuum pump, so that a vacuum system is formed. The vacuum membrane distillation type sewage treatment device is suitable for treating waste liquids containing heavy metal ions or purified seawater, has three functions of recycling water, concentrating waste liquid and saving energy and is characterized in that a refrigerant is used for recycling heat emitted by phase change of water steam, and the heat is used for heating sewage in the evaporator, so that the heat recycling effect is realized.

Description

technical field [0001] The invention belongs to the field of sewage treatment, in particular to a vacuum membrane distillation sewage treatment device capable of recovering heat. Background technique [0002] Membrane technologies currently used for seawater desalination mainly include electrodialysis (ED), reverse osmosis (RO) and membrane distillation (MD). However, the electrodialysis process has no ability to remove uncharged substances such as organic matter, bacteria, suspended matter, etc., and has high energy consumption and low water recovery rate; the reverse osmosis membrane itself also has some defects, such as scaling on the surface of the membrane However, the obvious decrease in flux caused by membrane distillation can effectively solve these problems. According to the different condensation methods on the cooling side of the membrane distillation membrane, the membrane distillation method can be divided into four types, namely, direct contact membrane distil...

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Problems solved by technology

However, the electrodialysis process has no ability to remove uncharged substances such as organic matter, bacteria, suspended matter, etc., and has high energy consumption and low water recovery rate; the reverse osmosis membrane itself also has some defects, such as scaling on the surface of the membrane The resulting significant decrease in flux, the use of membrane distillation methods can effectively solve these problems

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