Introduction to cryogenic concentration technology

Introduction to cryogenic concentration technology:

Cryogenic concentration is an innovative operation for separating brine by simulating the natural process of evaporation and rainfall and is an important part of the Zero Waste Water Disposal project. It works by using air or other gases to bring out the water molecules in the saline wastewater (humidification) and condense them at another place (de-humidification), thus achieving the purpose of concentrating the saline wastewater.
It is well known that concentration is a key step in the reduction of saline wastewater discharge. Most of the traditional concentration devices choose membrane concentration + evaporation concentration, the limit of the concentration membrane generally does not exceed 10%, and then further concentration to saturation requires evaporation concentration, the energy consumption of the whole concentration process is huge, usually accounting for more than 80% of all energy consumption, and more energy-efficient processes must be used to reduce operating costs.

In the traditional evaporation process:
1. membrane concentration process: calcium and magnesium ions must be removed in advance, silica ions are easy to cause membrane blockage, removal is difficult, while the PH needs to be ensured into a weak alkaline, otherwise it is easy to cause membrane poisoning and necrosis, the pre-treatment requirements are very high; even if the pre-treatment is up to standard, there are also the work requirements of diligent cleaning and replacement, personnel labor intensity and maintenance costs are high; limited by the osmotic pressure, membrane concentration can be concentrated to about 10% at most The zero discharge solution requires further concentration.
2. Evaporation and concentration process: high temperature operation, the stronger the chloride ion corrosiveness, higher requirements for equipment materials; the higher the concentration of brine, the higher the boiling point, the greater the energy consumption; negative pressure operation, easy to occur bubbling phenomenon, droplets with salt impact compressor, easy to damage equipment, while affecting the water quality; high temperature operation, heat exchanger is more likely to scale, heat transfer efficiency is seriously reduced, can not reach the evaporation amount; high temperature operation of the device safety requirements ye'yue