Solar gas scavenging membrane distillation system

Abstract

The invention discloses a solar gas sweeping membrane distillation system, which comprises a solar heat collector, a feed liquid tank, a hollow fiber membrane assembly group heat exchanger and a direct contact type condenser. According to the system, cheap energy is effectively utilized, and the water production cost is reduced; heat is directly exchanged through a steam-water interface, and condensation latent heat is recycled by preheating raw material water, so that the heat transfer coefficient of the condenser is greatly increased, the heat exchange area of a metal heat exchanger is reduced while high-noncondensable-gas-proportion mixed steam is effectively condensed, and the cost of the condenser is reduced; the distributor is used for dispersing mixed steam or cooling water, so thatthe steam-water interface heat exchange area is remarkably increased; various direct contact type condensers are adopted, so that the steam-liquid contact area is further increased, the steam-liquidcontact time is further prolonged, and the condensation efficiency is improved; the hollow fiber membrane modules are connected in series, so that the circulating temperature of feed liquid is reducedstep by step, and the heat cycle utilization rate of the system is effectively improved; and heat energy of discharged concentrated water is recycled and used for preheating raw material water, so that the heat utilization rate of the system is increased, and energy consumption of the system is reduced.

Description

technical field [0001] The invention belongs to the technical field of water treatment and membrane separation, relates to the technical field of heat exchanger structure, and particularly relates to a solar air-swept membrane distillation system combined with a direct contact condenser. Background technique [0002] Membrane distillation (MD) technology combines traditional distillation separation technology with membrane separation technology, and uses the hydrophobicity and certain structural functions of polymer membranes to achieve distillation and concentration of solutions. Membrane distillation technology is a non-isothermal physical separation technology. It uses the vapor pressure difference on both sides of the hydrophobic porous membrane as the driving force to realize the transmembrane transfer of water vapor and condense it into fresh water on the cold side. Different from the two traditional processes, membrane distillation does not need to heat the solution t...

AI Technical Summary

Problems solved by technology

However, based on its technological characteristics, the existence of a high proportion of non-condensable gas in the steam increases the heat transfer resistance of the condensation process. Using a traditional partitioned wall heat exchanger, it is necessary to increase the heat exchange area by more than 10 times to achieve effective condensation. The high cost of condensation Equipment cost has become a bottleneck restricting technology development

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