A kind of 2-chloronicotinic acid wet product drying process and its drying equipment

Abstract

The invention proposes a drying process for 2-chloronicotinic acid wet products and drying equipment. The drying process includes temperature-programmed and decompression operations, and the drying process is accelerated by rotating the drying equipment. The drying equipment includes: a double-cone drying cylinder, a rack , drive motor, steam pipeline, vacuum pipeline, steam generator and vacuum pump, the double-cone drying cylinder includes simplified and jacket layers, both sides of the double-cone drying cylinder can be rotatably installed on the frame, and the jacket on one side is The layer is communicated with the steam generator through the steam pipeline, and the inside of the cylinder on the other side is communicated with the vacuum pump through the vacuum pipeline. The inside of the frame is fixedly installed with a drive motor, which is connected by a pulley and a double-cone drying cylinder. The drying speed of 2-chloronicotinic acid, the drying operation is more flexible, the labor cost is reduced, and at the same time, it is convenient for enterprises to carry out equipment transformation, reducing equipment investment, and has a wide range of application value.

Description

technical field [0001] The invention relates to the production technology of chemical intermediates, in particular to a 2-chloronicotinic acid wet product drying process and drying equipment. Background technique [0002] 2-Chloronicotinic acid is an important fine chemical intermediate, which is used as an intermediate raw material for various drugs, insecticides, fungicides and herbicides, so it has broad market prospects before. [0003] However, due to the deficiency of the preparation process, the production capacity of 2-chloronicotinic acid is not high, and the production cycle is relatively long. The current process for synthesizing 2-chlorohydrochloric acid usually adopts the hydrolysis method of 2-chloro-3-cyanopyridine, through 2- Chloro-3-cyanopyridine is hydrolyzed under alkaline conditions, then pH is adjusted, cooled to crystallize, and the wet product of 2-chloronicotinic acid is obtained by means of solid-liquid separation, and the finished product of 2-chlo...

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Problems solved by technology

[0003] However, due to the deficiency of the preparation process, the production capacity of 2-chloronicotinic acid is not high, and the production cycle is relatively long. The current process for synthesizing 2-chlorohydrochloric acid usually adopts the hydrolysis method of 2-chloro-3-cyanopyridine, through 2- Chloro-3-cyanopyridine is hydrolyzed under alkaline conditions, then the pH is adjusted, the temperature is cooled and crystallized, and the wet product of 2-chloronicotinic acid is obtained by means of solid-liquid separation, and the finished product of 2-chloronicotinic acid is obtained after drying the wet product

At present, the commonly used drying process is to dry at a higher drying temperature for a fixed time. Since the solvent of 2-chloronicotinic acid wet product is water, it is easy to dissolve in water when the temperature is high, so the conventional drying process It is very easy to cause its drying agglomeration, or material loss during the drying process. Secondly, the current 2-chloronicotinic acid drying takes a long time, and the operation flexibility is not high, which is not conducive to improving the production efficiency of enterprises.

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