Method and device for continuously producing dyes

Abstract

The invention discloses a method and a device for continuously producing dyes. The method comprises the following steps: adding diazotization reaction raw materials into an ingredient kettle, controlling temperature in the kettle, allowing the materials to flow in a tubular reactor through an overflow orifice, detecting the reaction state through an online detection device, continuously discharging the diazotization compound solution obtained through the reaction, continuously feeding the diazotization compound solution and a coupling component solution according to a specified ratio, allowing the materials to flow into the tubular reactor through the overflow orifice, detecting the reaction state through the online detection device, transferring the coupling reaction materials into a crystal transformation kettle, performing crystal transformation, and performing filter pressing to obtain a dye filter cake, wherein the filter cake mother solution and the wash water are circulated for preparing the coupling component solution. The reaction temperature, material flow and reaction state detection device are automatically subjected to interconnected control. According to the method, automatic and continuous dye production is realized, the production capacity, the product quality and yield are improved, the labor intensity and working conditions of workers are improved, the waste water, water gas and waste residue amounts in the dye production process are greatly reduced, and circular economy and cleaner production process are realized.

Description

technical field [0001] The invention relates to a method for continuously producing dyes and a device for realizing the method. Background technique [0002] The dye industry is one of the industries with the longest history in the fine chemical industry. In recent years, with the development of my country's light textile industry, the dye industry has also developed rapidly; especially since the beginning of the new century, my country's dye industry has developed more rapidly, and its output, export volume and consumption have all ranked first in the world. [0003] The preparation of general dyes consists of batch-type diazotization reactions and coupling reactions. In the diazotization reaction, the diazonium salt is easy to decompose at high temperature, and the preparation of the diazonium salt is an exothermic reaction. Therefore, the production process requires quite high heat transfer. In the coupling reaction, the diazonium salt is also easy to decompose. If the ...

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Problems solved by technology

[0004] In a conventional batch reactor, it is difficult to ensure that all areas of the reactor are stirred evenly, the local chemical ratio deviates from the reaction conditions, and the temperature in the reactor is uneven, which will lead to the decomposition of the diazonium salt and the occurrence of various side reactions. Resulting in poor quality of diazonium salt, low purity of dyestuff and low yield

[0005] At present, the production methods of dyestuffs in my country are still relatively backward, automatic control technology has not been practically applied in the dyestuff production process, and the comprehensive automation level of enterprises is generally low

The reason for this is that the dye production process is complicated, the operation is complicated, the process medium is toxic, corrosive, flammable and explosive, the safety requirements for production are high, and it is difficult to automatically detect the reaction end point and quality in automatic control. Feedback and other reasons

[0006] In addition, as a traditional fine chemical industry, the dye industry has a large amount of "three wastes" (waste water, waste gas, and waste residue), especially waste water pollution, which restricts the development of the entire industry.

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