A continuous evaporation crystallizer and evaporation system for light solids

Abstract

The invention relates to a continuous evaporating crystallizer of a light solid and an evaporating system. The continuous evaporating crystallizer comprises a tank body, a feed inlet, a steam outlet, a liquid outlet and a crystal slurry extraction tube. The feed inlet is formed in the middle of the tank body, the steam outlet is formed in the upper end of the tank body, the liquid outlet is formed in the lower end of the tank body, a horn-shaped flared opening is formed in the middle of the tank body, and the large opening of the horn-shaped flared opening faces downward while the small opening thereof faces upward, and one end of the crystal slurry extraction tube in the tank body is connected to the small opening of the horn-shaped flared opening. According to the continuous evaporating crystallizer provided by the invention, crystal slurry is extracted above a solution. The continuous evaporating crystallizer provided by the invention is suitable for continuous stable industrial evaporating crystallization of light solids, such as calcium propionate, which are smaller than liquids in density. The continuous evaporating crystallizer provided by the invention can make sure separation of two processes: solution heating and water evaporation in spatial space.

Description

technical field [0001] The invention relates to an evaporative crystallization device, in particular to a continuous evaporative crystallizer and an evaporator system for light solids whose density is lower than that of liquid. Background technique [0002] The crystallization process is an important operation unit in the chemical process and an important link in the production of chemical products. It is also widely used in other industrial sectors. The density of the solid product is usually greater than the solution density, so the continuous crystallization device commonly used in industry at present such as Oslo crystallizer, DTB crystallizer all is to extract the crystal slurry from the bottom of the crystallization vessel, and then obtains the solid product through filtration and / or drying process ( Ye Tielin, "Chemical Crystallization Process Principles and Applications", Chemical Industry Press, 2006). [0003] Calcium propionate is an important food additive, wide...

AI Technical Summary

Problems solved by technology

Propionic acid reacts with calcium carbonate or calcium hydroxide in the water phase to obtain an aqueous solution of calcium propionate. Since the density of calcium propionate is smaller than that of the solution, it is generally evaporated by intermittent partition heating after the reaction produces calcium propionate. Most of the water is concentrated crystal slurry (US P4700000, 1987; Jia Zhenyu et al. Guangdong Chemical Industry, 1999, No. 2, page 93), which cannot realize large-scale continuous stable production

Chen Guangyu and others passed the calcium propionate solution into the falling film evaporation device to concentrate (Packaging and Machinery, Issue 3, 2015, page 97), which can realize the continuous process, but the solution heating and water evaporation are carried out at the same time, which will cause the solid calcium propionate to be heated. a large amount of deposition on the surface

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