Membrane evaporating and concentrating method and device

Abstract

The invention provides membrane evaporating and concentrating device and method, wherein the membrane evaporating and concentrating device comprises a membrane evaporating water tank, a fan, a heat exchanger and dewatering membrane assemblies, wherein low-pressure steam enters the membrane evaporating water tank; the fan is arranged outside the membrane evaporating water tank and used for blowingcompressed air into a membrane assembly in the membrane evaporating water tank; the heat exchanger is connected with a water outlet of the membrane assembly and used for heating raw water; and the dewatering membrane assemblies in the membrane evaporating and concentrating device are respectively arranged in a liquid-phase basic membrane zone and an air-phase basic membrane zone. The membrane evaporating and concentrating device has the advantages that (1) the membrane pollution is slowed down, thereby the distillation flux of membranes is improved; (2) the membrane evaporating and concentrating device carries out filtration and cooling condensation to damp and hot air-containing tail gas, thereby preventing spray pollution to obtain the water quality of produced water with low conductivity; (3) by adopting flocculated air-float impurity removal and membrane clarifying filtration, the membrane evaporating and concentrating device discharges most of organic pollutants out of a membraneevaporating system, thereby reducing the pollution in a membrane distilling process and improving the concentration multiples; and (4) the membrane evaporating and concentrating device not only recovers the heat quantity of the gas produced by membrane distillation, but also recovers the heat quantity of the damp and hot air-containing tail gas, thereby further reducing the energy consumption of the membrane evaporating system.

Description

technical field [0001] The invention relates to a membrane evaporation concentration method and a device thereof, in particular to a membrane separation treatment method for high brine treatment and chemical concentration separation and a device thereof. Background technique [0002] Compared with ordinary evaporators, one of the most notable features of membrane distillation technology is that the evaporation area per unit volume is large, corrosion-resistant, and not easy to scale, so that the device can operate efficiently in the evaporation process at a lower temperature, and the distillation The vapor space required for operation is very small. Compared with reverse osmosis, membrane distillation is a heat-driven process with low operating pressure, so the requirements for membrane mechanical properties are low, equipment costs are also low, and process safety is improved. Moreover, membrane distillation has low operating pressure and high desalination rate , less memb...

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Problems solved by technology

[0006] However, there are generally problems in the membrane distillation process: 1. The problem of heat energy utilization in the membrane distillation process

2. With the progress of the membrane evaporation concentration process, the raw material liquid is continuously concentrated, resulting in an increase in the concentration of COD and other pollutants in the raw material liquid, which makes the membrane fouling problem serious

3. Although the conventional vacuum membrane distillation process has good water quality and high efficiency, the operation consumes a lot of energy

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