Mechanical steam recompression falling film evaporation process method and system

Abstract

The invention provides a mechanical steam recompression falling film evaporation process method comprising the following specific steps: (1) high-salt wastewater pretreatment is carried out, wherein a material is delivered into a preheater through a feeding pump; condensate water of falling film evaporator secondary steam condensation is adopted as a heat source of the preheater, and the material is preheated; the preheated material is delivered into a liquid mixing device, and is mixed with liquid from an evaporation chamber of the falling film evaporator; and the mixture is delivered into the falling film evaporator; (2) a falling film evaporation system is established, wherein after the material enters the falling film evaporator, with indirect heating of evaporator shell-side steam, the material absorbs heat and the temperature is increased; the material enters the evaporation chamber; with the negative pressure in the evaporation chamber, the material is instantly evaporated, and most of water is converted into secondary steam and is discharged from a secondary steam outlet; and (3) a steam compression recycling system is established, wherein secondary steam from the evaporation chamber enters a steam compressor; with the compression of the steam compressor, steam pressure and temperature are both increased; and the steam is returned to the shell-side of the falling film evaporator again and is reused.

Description

technical field [0001] The invention relates to a mechanical vapor recompression evaporation system (MVR), which is mainly used in a high-salt wastewater treatment system. It can evaporate, concentrate and crystallize the salt in the wastewater, and the condensed water can be recycled, and the salt solid can be used as A system that recycles resources and realizes "zero discharge" of waste water. Background technique [0002] As early as the 1960s, Germany and France had successfully applied mechanical vapor recompression technology to chemical, pharmaceutical, papermaking, sewage treatment, seawater desalination and other industries. [0003] "Mechanical Vapor Recompression" evaporation system referred to as MVR evaporator is the abbreviation of English (Mechanical Vapor Recompression). It is a new type of high-efficiency and energy-saving evaporation equipment developed in the late 1990s in the world. MVR evaporator adopts low-temperature and low-pressure steaming techno...

AI Technical Summary

Problems solved by technology

With the rapid development of the economy, the pollution of my country's water environment is becoming more and more serious, so "zero discharge" of wastewater from industrial enterprises has been put on the agenda. At present, the evaporation devices in domestic high-salt wastewater treatment systems mostly use ordinary multi-effect evaporation devices. Compared with the mechanical vapor recompression evaporation system (MVR evaporation system), the energy consumption is higher, the stability is lower, the floor area is larger, and the operating cost is higher

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