Evaporation and concentration system and method

Abstract

The invention relates to an evaporation and concentration system. The evaporation and concentration system comprises a raw material tank, a feeding pump, a heater, a wiped-film evaporator, a crystal grower and a liquid-solid separator, which are sequentially connected with one another, wherein a liquid outlet of the liquid-solid separator is connected with the raw material tank; a jacket is arranged on the outer surface of the heater; an inlet is formed in the upper part of the jacket; an outlet is formed in the lower part of the jacket; the inlet of the jacket is communicated with an air outlet formed in the top of the wiped-film evaporator; the outlet of the jacket is connected with a gas-liquid separator and a jet pump sequentially. The evaporation and concentration system provided by the invention has the advantages of energy conservation and high efficiency, zero discharge in a concentration process is realized, and good evaporation conditions are created.

Description

Technical field [0001] The invention relates to an evaporation system in the chemical industry, in particular to an evaporation concentration system using a wiped film evaporator, and a method for concentration using the system. Background technique [0002] The purpose of the evaporation operation in chemical production is: to obtain a concentrated solution directly as a chemical product or semi-finished product; to remove the solvent by evaporation, to obtain a solid solute through a combined operation of crystallization; to remove impurities to prepare a pure solvent. [0003] The evaporator has a variety of structural forms, all of which are composed of a heating chamber, a flow (or circulation) channel, and a gas-liquid separation space. The evaporator can be divided into single-effect evaporator, multi-effect evaporator, vapor compression evaporator, flash evaporator and direct contact evaporator according to the operation mode; according to the fluid circulation mode, it can...

AI Technical Summary

Problems solved by technology

[0005] The scraper of the wiped film evaporator is made of hard material. The distance between the scraper and the inner wall of the evaporation cylinder is generally 0.2-2mm. In order to avoid corrosion, the evaporation cylinder is generally made of graphite. When the axial force of the scraper is uneven , it is easy to rub against the inner wall of the graphite, and then damage the graphite evaporation cylinder. In addition, the scraper and the graphite evaporation cylinder are in line contact. When the steam temperature on the jacket is uneven or the temperature changes greatly, it is easy to adhere to the inner wall of the evaporation cylinder. For larger and harder crystal blocks, the scraper will stop rotating when it cannot scrape off the crystal block, which will cause the entire wiped film evaporator to fail to operate normally. Only when the crystal block is scraped off manually can the wiped film evaporation be restarted device

[0006] In addition, the evaporation system using a wiped film evaporator has low utilization rate of heat energy and poor concentration efficiency

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