Continuous dilution device and continuous dilution method for cooling devitrification of 4-acetamidobenzenesulfonyl chloride

Abstract

The invention discloses a continuous dilution device and a continuous dilution method for cooling devitrification of 4-acetamidobenzenesulfonyl chloride. The continuous dilution device comprises two heat exchange units, a diluted water unit, a feed liquid adding unit, a continuous diluting and mixing circulation unit and a diluted liquid collection unit; the first heat exchange unit is used for heat exchange of diluted water; the second heat exchange unit is used for cooling a diluting material to separate out the 4-acetamidobenzenesulfonyl chloride through crystallization; the diluted water unit comprises a diluted water tank and a diluted water discharge pump; the feed liquid adding unit comprises a 4-acetamidobenzenesulfonyl chloride hydrolysate adding unit and a washing unit. The continuous dilution method includes the steps of online continuous feeding, circular dilution, cooling crystallization and discharge of 4-acetamidobenzenesulfonyl chloride hydrolysis materials. The continuous dilution device and the continuous dilution method have the advantage that online continuous feeding, circular dilution and cooling crystallization can be realized to obtain high-quality products.

Description

technical field [0001] The invention relates to a continuous dilution device and method for cooling and crystallizing p-acetylaminobenzenesulfonyl chloride. Background technique [0002] P-Acetaminobenzenesulfonyl chloride is an important chemical intermediate, which is commonly used in the preparation of sulfonamide fungicides and antifungal drugs. It can also be used to synthesize dye intermediates such as para-ester and para-amino oil, and can also be directly Used to craft dyes. It is widely used in fields such as medicine, coatings, plastics and pesticides. [0003] At present, most of the production of acetaminophensulfonyl chloride adopts the traditional process of excessive chlorosulfonic acid method, and the hydrolyzed material of the synthetic intermediate product needs to be diluted with water to precipitate the crystals of acetaminophensulfonyl chloride. A common method is to use a stirring dilution tank, a storage tank and a discharge pump to form an intermitt...

AI Technical Summary

Problems solved by technology

The main disadvantages of this method are: (1) the number of dilution equipment used is large and the floor area is large, which causes a lot of inconvenience to the layout of workshop equipment, and the equipment cost is high and the utilization rate is low; (2) the heat exchange area of ​​the dilution kettle used is small and the temperature difference is large , the dilution efficiency is low, the dilution time is long, often reaching more than ten hours, the consumption of frozen brine is large, and the cost is high; Unevenness will easily lead to material wall formation, and due to the large temperature difference in the material system, it may cause local overheating and affect the quality of the material; (4) In order to speed up the cooling rate, a certain amount of ice cubes are often put into the dilution tank for cooling. Cooling, ice weighing, handling and feeding are all manual operations, which are labor-intensive and inconvenient to operate

[0005] Chinese patent 200952647.Y discloses an on-line continuous dilution and addition device for stock solution, which can realize on-line continuous dilution and addition of high-viscosity liquids, but still has the following deficiencies: (1) It cannot control the temperature change of the material during the dilution process, and some The material will release a lot of heat during the dilution process. If the temperature change of the material system cannot be controlled in time, the quality of the material may be affected; (2) It does not have the function of continuously diluting the material, and only the original solution and the diluted solution are passed through a simple Mixing with a mixer makes it difficult to achieve the ideal dilution effect of "uniform mixing"; (3) It is only used for online continuous dilution and addition of high-concentration liquids, and does not have the function of a "reactor" for the cooling and crystallization process of materials

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