A kind of decompression multi-effect membrane distillation method and its device

Abstract

The purpose of the present invention is to provide a method of decompression multi-effect membrane distillation and its device. Inside the membrane distillation combination element, the hot feed liquid flows from top to bottom, and the negative pressure evaporation occurs during the flow process and is cooled; the generated steam The cold fluid is heated by the heat exchange wall and condensed; at the same time, the cold feed liquid flows from bottom to top, and evaporates under negative pressure while being heated by the heat exchange wall. The evaporation and cooling of the hot feed liquid and the heating and heating of the cold feed liquid are continuous stepless processes, which can realize efficient multi-effect evaporation. The decompression multi-effect membrane distillation method proposed by the present invention, by coupling the condensation of water vapor generated in the membrane distillation process with the heating process of the feed liquid, has a higher membrane distillation flux under the condition of high water production ratio, and at the same time , can significantly reduce the amount of additional cooling water. Through the multi-effect membrane distillation process designed by the invention, a membrane distillation process with high efficiency and low energy consumption can be realized, and the heat recovery rate is high.

Description

technical field [0001] The invention relates to a membrane distillation method and a device thereof, in particular to a vacuum multi-effect membrane distillation method and a device thereof for concentrated treatment of high-salinity waste water and separation and concentration of industrial materials. Background technique [0002] Membrane distillation technology is a new type of liquid separation technology combined with membrane technology and traditional distillation technology. Compared with ordinary evaporators, one of the most notable features of membrane distillation is that the effective evaporation area per unit volume is large, so that the device can be used under normal pressure, It operates efficiently in the evaporation process at a lower temperature, and the equipment is made of plastic materials, which avoids the corrosion of metal materials in the treatment of high-salinity materials. Membrane distillation is a membrane separation process that uses a hydroph...

AI Technical Summary

Problems solved by technology

However, due to the phase change process in the separation process, so far, membrane distillation technology has the problem of high energy consumption.

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