2-benzothiazolethiol nitrogen circulation drying and solvent recovery method

Abstract

The invention relates to a 2-benzothiazolethiol nitrogen circulation drying and solvent recovery method. The method comprises the following steps: (1) conveying a 2-mercaptobenzothiazole wet material in a vacuum drying chamber of a vacuum paddle dryer, filling gaps between wedged blades with the 2-mercaptobenzothiazole wet material, meanwhile, introducing steam in a paddle shaft of the vacuum paddle dryer and a jacket of a housing of the vacuum paddle dryer, and thus obtaining the dried material and the evaporated moisture; (2)turning the dried material over an overflow weir to be discharged from a discharging opening, allowing the dried material to enter a seal buffer tank through a rotary discharge valve I, meanwhile, introducing nitrogen in the seal buffer tank for nitrogen sealing, and conveying the dried material to a next process by a rotary discharge valve II at the bottom of the seal buffer tank; (3) carrying the evaporated moisture out by hot nitrogen and allowing hot nitrogen to enter a cooling washing tower to be sprayed so as to obtain washed nitrogen; (4) pressurizing and heating washed nitrogen, enabling the pressurized and heated nitrogen to enter the vacuum paddle dryer to serve as a carrier gas for conveying the evaporated moisture for cyclic utilization. The method has the advantages of being safe, environment-friendly, and low in energy consumption.

Description

technical field [0001] The invention relates to the technical field of safety, environmental protection, energy saving and consumption reduction in the production of 2-mercaptobenzothiazole, in particular to a nitrogen circulation drying and solvent recovery method of 2-mercaptobenzothiazole. Background technique [0002] The existing industrial production process of 2-mercaptobenzothiazole adopts the traditional airflow drying process. In the production of 2-mercaptobenzothiazole, the wet material of 2-mercaptobenzothiazole after reaction contains water, methanol solution and a small amount of CS 2 , when drying 2-mercaptobenzothiazole, it is necessary to remove methanol and CS in the wet material of 2-mercaptobenzothiazole 2 , the process method is: after the air is heated, the 2-mercaptobenzothiazole is dried by the air dryer, and the water, methanol and CS 2 All evaporation is carried out by the dry air and discharged. [0003] The disadvantage of this process technol...

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Problems solved by technology

[0003] The disadvantage of this process technology is: the process adopts an air open circuit system, because the 2-mercaptobenzothiazole wet material contains a small amount of CS 2 , during the drying process often flash and CS 2 It is irritating and toxic, endangering personal safety and affecting the environment; the methanol solvent in the 2-mercaptobenzothiazole wet material is seriously wasted, and it is discharged with hot air during the drying process, which affects the environment and causes waste; the wet material uses The air flow is dry, the air is heated by steam, the thermal efficiency is low, and the energy consumption is high

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