Device for preparing ammonia through pyrolysis of urea

Abstract

The invention relates to a device for preparing ammonia through pyrolysis of urea. The device comprises a reactor body (2) provided with a spray gun (3), and inlets and an outlet (5) of the reactor body (2); the inlets are arranged at the upper part of the reactor body (2); the outlet (5) is arranged at the lower part of the reactor body (2); the inlets comprise at least two gas inlet pipes (1); the gas inlet pipes (1) are positioned at the upper part of a reactor wall, and each form a certain angle with the reactor wall. The fact that the gas flow inside the pyrolysis reactor forms a rotational flow is realized; the effect of mixing warm air and an atomized urea solution is excellent, and the distribution of a gas flow field and a temperature field is more uniform; the reaction residence time is prolonged, so that complete decomposition of urea is facilitated; and meanwhile, the reactor body has a simple structure.

Description

technical field [0001] The invention relates to a urea pyrolysis device, in particular to a urea pyrolysis ammonia production device whose inlet is a plurality of pipelines uniformly distributed on the reactor body and forming a certain angle with the side wall of the reactor. Background technique [0002] Nitrogen oxide (NOx) is one of the main air pollutants. With the implementation of strict environmental protection standards, the flue gas denitrification system has become one of the essential equipment for thermal power plants. Selective Catalyst Reduction (SCR) ) has become the first choice of technology for power plant denitrification projects due to its high denitrification efficiency, and has been more and more widely used. There are three sources of reducing agent NH3 in SCR technology: liquid ammonia, ammonia water and urea. Urea is selected as the reducing agent, which has the characteristics of high safety, wide range of sources, easy transportation and storage, ...

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Problems solved by technology

Yet because used ammonium bicarbonate is solid particle, in order to make described solid particle decompose and needs violent impact motion, so the hot air in the described pyrolysis furnace needs to be designed to rotate and flow, and the hot air inlet is set at pyrolysis The lower part of the furnace, the swirling air flow at the lower part ensures that the solid particles do not fall to the ground, and the urea used in the production of ammonia from urea is a solution, which requires hot air with a stable flow rate from top to bottom, so the above-mentioned pyrolysis device for ammonium bicarbonate is not suitable for Pyrolysis of urea

[0008] The pyrolysis device for producing ammonia from urea disclosed in patent document CN201907975U includes a gas inlet, a reaction chamber with a spray gun inside, and a gas outlet. The gas inlet is arranged on the upper part of the reaction chamber, and the gas outlet is arranged on the The lower part of the reaction chamber also includes a sieve-type air distribution device arranged inside the reaction chamber and on the upper part of the spray gun, and a sieve-type air distribution device with a plurality of openings is arranged inside the reaction chamber and on the upper part of the spray gun, In the diffusion process of the hot air entering the pyrolysis device, a uniform downward flow of hot air flow field is obtained faster, and the relative arrangement position of the spray gun is improved, so that the pyrolysis device has a shorter length requirement, effectively reducing the The height of the pyrolysis device, however, the airflow must enter through the orifice plate with many fine holes, the resistance is very large, which will cause pressure loss

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