Continuous evaporative crystallization device and method for 4-cyanopyridine

Abstract

The invention discloses a continuous evaporative crystallization device and method for 4-cyanopyridine. The device comprises a pressurizing assembly, a connecting pipe and an evaporation reaction kettle, and is characterized in that the pressure in the evaporation reaction kettle is increased by the pressurizing assembly so as to the crystallization temperature of the 4-cyanopyridine and the boiling point temperature of other organic solvents, after pressurization is completed, a heating resistor is used for heating and crystallizing part of the solution to ensure that only water and other organic solvents are vaporized and the 4-cyanopyridine is heated and crystallized in the evaporation and crystallization process of the 4-cyanopyridine, and meanwhile, water vapor, the other organic solvents and part of the 4-cyanopyridine are absorbed and liquefied again by a condensation reflux box, and drop on the right side of the evaporation reaction kettle, and the heating resistor on the right side carries out evaporative crystallization operation under normal pressure again, so that the 4-cyanopyridine is separated out after being crystallized and is attached to the inner wall of the right side of the evaporation reaction kettle, the crystallization operation steps of the 4-cyanopyridine are simplified, and the crystallization amount of the 4-cyanopyridine separated out is effectively increased.

Description

technical field [0001] The invention relates to the technical field of evaporation crystallization equipment, in particular to a 4-cyanopyridine continuous evaporation crystallization device and method. Background technique [0002] 4-cyanopyridine, which has the formula C 6 h 4 N 2 , with a molecular weight of 104.11, is a white to pale yellow needle-like crystal with a characteristic odor, soluble in ethanol, ether and benzene, and is mainly used as intermediate products of medicine and pesticide, which are usually stored in a cool and ventilated warehouse , away from fire and heat sources, and should be stored separately from oxidants, and should not be stored together. Store in a sealed environment, use explosion-proof lighting and ventilation facilities, prohibit the use of mechanical equipment and tools that are prone to sparks, and the storage area should be equipped with leakage emergency treatment equipment and suitable containment materials. When the preparation...

AI Technical Summary

Problems solved by technology

Store in a sealed environment, use explosion-proof lighting and ventilation facilities, prohibit the use of mechanical equipment and tools that are prone to sparks, and the storage area should be equipped with leakage emergency treatment equipment and suitable containment materials. When the preparation of 4-cyanopyridine is completed, it is usually in In the state of the solution, 4-cyanopyridine is usually crystallized and recovered by evaporative crystallization. In the process of evaporative crystallization, it is difficult to control the evaporation temperature, and other substances in the organic solution can easily make 4-cyanopyridine Simultaneous vaporization, resulting in less crystallization of 4-cyanopyridine crystals

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