A urea spiral heating reaction device and its application

Abstract

The invention relates to a spiral-heating reaction device for urea and application the spiral-heating reaction device. The spiral-heating reaction device comprises a reactor, a feeding bin and a discharging bin, wherein the reactor is of a cylinder structure, and the feeding bin and the discharging bin are respectively arranged on the reactor; a stirring shaft is arranged in the reactor, the surface of the stirring shaft is spirally provided with fins and the stirring shaft is connected with a stirring shaft motor; a heating device is arranged at the outer side of the reactor, and the discharging bin is provided with a gas outlet and a discharging opening. The spiral-heating reactor device has the advantages that materials are pushed to advance spirally by the fins spirally arranged on the stirring shaft, so that the heat transferring is uniform, the local heating for the materials and the generation of excessively-condensed side products and amine derivatives are avoided and the purity of reaction products is improved; and the fins of the stirring shaft are close to the inner wall of the reactor, so that the occurrence of the wall-sticking phenomenon in the reaction process is avoided.

Description

[0001] Technical field: [0002] The invention relates to a urea spiral heating reaction device and its application, belonging to the technical field of material heating equipment. [0003] Background technique: [0004] The production method of existing cyanuric acid is mainly urea pyrolysis. There are two types of pyrolysis methods: solid-phase method (melt method) and liquid-phase method (solvent method). The reaction equation of generating cyanuric acid is as follows: [0005] [0006] Both methods are to put solid urea into a reactor, and produce cyanuric acid by heating urea to 200-300°C with or without a catalyst, with or without a solvent. [0007] There are pros and cons to both approaches. The liquid phase method refers to suspending urea in an organic solvent, heating and polymerizing in a reactor, then removing the solvent, washing with water, and drying to obtain a high-purity product. The solvents used in the production of cyanuric acid by the solvent metho...

AI Technical Summary

Problems solved by technology

The molten urea produced during the heating process of the melting pyrolysis method is easy to adhere to the reactor wall and the agitator, resulting in difficulty in heat transfer, high temperature near the wall, and excessive condensation of by-products and amine derivatives. The purity is not high

Although the material return method solves the phenomenon of material sticking to the wall, it requires a large return multiple, resulting in high energy consumption and reduced equipment capacity

The molten salt pyrolysis process is complicated, consumes a lot of energy, and the conversion rate of urea is low, and the equipment is seriously corroded

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