A rotary cross-flow vacuum membrane distillation device

Abstract

The invention discloses a rotating cross-flow type vacuum membrane distillation device. The rotating cross-flow type vacuum membrane distillation device mainly comprise a raw water storage tank, a raw water heating water tank, a rotating cross-flow type hydrophobic membrane module, a condenser, a cooling water tank, a vacuum buffer tank, a vacuum pump and a water production tank. Raw water enters the heating water tank from the raw water storage tank and is heated, hot water is reserved outside the rotating cross-flow type hydrophobic membrane module, steam then enters hollow membrane module units through the membrane and is merged into a hollow shaft under the guiding action of the vacuum pump, further enters the condenser and condensed water flows into the water production tank. During the membrane distillation, the hydrophobic membrane module rotatably runs in a program-controlled manner; by the centrifugal force, hydrodynamic shear force and strong flow turbulence generated by the movement, the self-cleaning of the surface of the permeable membrane is achieved, the influences of concentration polarization and temperature polarization are effectively avoided, the pollution caused by salt crystallization, scaling, a gel layer and organic substances can be decreased, the cleaning period and service life of the permeable membrane module are prolonged and meanwhile, the heat utilization rate of the system is increased.

Description

technical field [0001] The invention belongs to the technical field of membrane separation, and relates to a seawater desalination or desalination treatment device containing brine, in particular to a rotary cross-flow vacuum membrane distillation device. Background technique [0002] Membrane distillation (Membraned stillation, MD) process is a new type of desalination and desalination technology that combines membrane technology with traditional distillation technology. Compared with conventional distillation (distillation), MD operates at a lower temperature, generally operating at a temperature of about 70°C, without heating the solution to boiling, and has a large evaporation area and a small vapor space, so it can remove higher concentrations of salt And has a higher desalination rate. The membrane used in membrane distillation is a hydrophobic microporous membrane that is not wetted by the solution to be treated, that is, only steam can enter the membrane pores, and l...

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Problems solved by technology

[0004] At present, the existing membrane distillation technologies at home and abroad all use static hollow fiber membrane modules and plate-and-frame membrane modules, and rely on air blowing and aeration to form cross-flow. Distillation and Patent CN101659451A An air-lift membrane distillation high-salt water treatment method uses aeration to eliminate concentration polarization and temperature polarization, high energy consumption, and hydrophobic hollow fiber membrane filaments are easily broken

Patent No. CN102417210A A submerged vacuum membrane distillation device and its sewage treatment method also use static hydrophobic hollow fiber or plate-and-frame membrane modules, and a dissolved air pump to provide uniform micro-bubbles to form a cross-flow, which solves the problem of aeration operation. Broken wire problem, but the micro-bubble disturbance effect is small, which is not conducive to eliminating concentration difference and temperature difference polarization

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