Double-stage MVR evaporation and crystallization process and equipment

Abstract

The invention is mainly applied to the fields of chemical engineering and process, and in particular relates to a double-stage MVR evaporation and crystallization process and double-stage MVR evaporation and crystallization equipment. The process comprises the following steps: inputting raw material liquid into a primary evaporator to perform heating, inputting the heated material liquid into a primary separation chamber to perform vapor and liquid separation, inputting the obtained liquid phase, cycling material liquid of a secondary separation chamber and a desalted liquid phase into a secondary evaporator to perform heating, inputting the heated material liquid into the secondary chamber to perform vapor and liquid separation, and inputting the obtained liquid phase into a desalting device to perform desalting; and after compressing the vapor phase obtained by the secondary separation chamber by a secondary compressor, inputting the compressed vapor phase and the vapor phase obtained by the primary separation chamber into a primary compressor, performing compression by the primary compressor, inputting the compressed vapor phases serving as heating sources into the primary evaporator and the secondary evaporator correspondingly to heat the material liquid, condensing into condensate after heating, inputting the condensate into a condensate storage tank, collecting and discharging. By implementation of the process method and the equipment, equipment investment can be obviously reduced, the process energy consumption can be reduced, and process operation and control are simplified.

Description

technical field

[0001] The invention relates to a two-stage MVR evaporation crystallization process and equipment, which are mainly used in the field of chemical engineering and technology. Background technique

[0002] In the production and application of dimethyl sulfoxide, the desalination and recovery of dimethyl sulfoxide is an essential process requirement. The desalination process of dimethyl sulfoxide is generally realized by evaporation. During the production process, evaporation requires external steam to provide heat, and the evaporated dimethyl sulfoxide needs to be condensed and recovered. Since dimethyl sulfoxide is easy to decompose at a temperature higher than 140°C, it may even cause production safety accidents. In order to improve the product quality of dimethyl sulfoxide and ensure production safety, the temperature in the production process should be lower than 100°C. Under the above production process requirements, the existing production technology eq...

Examples

Embodiment

[0021] The raw material liquid contains 32%wt of dimethyl sulfoxide and 15%wt of sodium nitrate, which is subjected to desalination treatment, and the dimethyl sulfoxide therein is recovered and reused. The raw material liquid is input into the primary evaporator 1 through the raw material pipeline (processing capacity 1500kg / h), the temperature of the raw material liquid is 57°C, and the operating parameters of the primary separation chamber 6 are: evaporation pressure 7kPa, evaporation temperature 98°C; secondary separation chamber 4 The operating parameters are: evaporation pressure 3kPa, evaporation temperature 98°C. In this embodiment, what is collected by the condensate storage tank 7 is the dimethyl sulfoxide product that needs to be recovered after desalination.

technical field

[0001] The invention relates to a two-stage MVR evaporation crystallization process and equipment, which are mainly used in the field of chemical engineering and technology. Background technique

[0002] In the production and application of dimethyl sulfoxide, the desalination and recovery of dimethyl sulfoxide is an essential process requirement. The desalination process of dimethyl sulfoxide is generally realized by evaporation. During the production process, evaporation requires external steam to provide heat, and the evaporated dimethyl sulfoxide needs to be condensed and recovered. Since dimethyl sulfoxide is easy to decompose at a temperature higher than 140°C, it may even cause production safety accidents. In order to improve the product quality of dimethyl sulfoxide and ensure production safety, the temperature in the production process should be lower than 100°C. Under the above production process requirements, the existing production technology eq...

Examples

Embodiment

[0021] The raw material liquid contains 32%wt of dimethyl sulfoxide and 15%wt of sodium nitrate, which is subjected to desalination treatment, and the dimethyl sulfoxide therein is recovered and reused. The raw material liquid is input into the primary evaporator 1 through the raw material pipeline (processing capacity 1500kg / h), the temperature of the raw material liquid is 57°C, and the operating parameters of the primary separation chamber 6 are: evaporation pressure 7kPa, evaporation temperature 98°C; secondary separation chamber 4 The operating parameters are: evaporation pressure 3kPa, evaporation temperature 98°C. In this embodiment, what is collected by the condensate storage tank 7 is the dimethyl sulfoxide product that needs to be recovered after desalination.

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