Nozzle for urea pyrolysis device

Abstract

The invention discloses a nozzle for a urea pyrolysis device, which is characterized in that it includes a straight section of an outer casing connected in sequence, an inner casing inserted and fixed in the outer casing, an accelerating section of the inner casing whose cross-section is continuously reduced, located The mixing section at the throat of the outer casing that first shrinks and then expands before the acceleration section of the inner casing, the transition straight section located in front of the mixing section, the open-hole stepped stop connected to the transition straight section and the open-hole stepped stop Opening arc ends where blocks are connected. The straight section of the outer casing has a nozzle connected to the urea solution, the end of the inner casing inserted and fixed in the outer casing is extended and connected to the compressed air, and the front part of the mixing section is connected to the transition straight section. The block and the arc-shaped end of the opening connected thereto form an annular chamber, and the annular chamber is provided with an opening. The mixed and atomized urea solution and bubble mixture are further broken through the two-stage openings of the annular chamber, and then atomized and sprayed out. The invention can effectively atomize and spray the urea solution without increasing energy consumption.

Description

technical field [0001] The invention relates to a nozzle, in particular to a nozzle used for a urea pyrolysis device, and belongs to the technical field of structural components of an air-flow atomization spray gun. Background technique [0002] As my country's environmental protection continues to increase, most coal-fired power plant boilers are equipped with flue gas denitrification devices. Among them, the selective catalytic reduction (SCR) denitrification process has been widely used at home and abroad due to its mature technology and reliability, accounting for about 90% of the installed denitrification capacity. Some power plants are relatively close to cities and residential areas, and there are restrictions on the transportation and use of reducing agents such as liquid ammonia and ammonia water. Therefore, the urea pyrolysis ammonia production process has been widely used in the preparation of reducing agents for denitrification devices. [0003] In the actual op...

AI Technical Summary

Problems solved by technology

[0003] In the actual operation of the ammonia production process using urea pyrolysis, crystallization and blockage problems have appeared in varying degrees on the inner wall of the urea pyrolysis furnace and the bottom of the pyrolysis furnace. The main reason is that the atomization effect of the urea atomization spray gun is poor, that is, the atomization The nozzle of the spray gun does not meet the actual design requirements

Because the nozzle of the atomizing spray gun has too large coverage when spraying, the urea solution will be sprayed directly onto the inner wall of the pyrolysis furnace, forming a low temperature zone and causing crystallization; if multiple urea spray guns are running at the same time, the spray coverage of each atomizing spray gun will overlap. It is easy to form a "cross coverage" area, in which the atomized fine droplets collide with each other and merge to form larger droplets, thereby intensifying the generation of crystallization at the bottom of the pyrolysis furnace

In addition, the nozzles of the existing atomizing spray guns lack the gas-liquid mixing area, or the volume of the mixing area is extremely small, which will greatly reduce the flow rate of the atomizing air volume during the gas-liquid mixing, thereby reducing the atomization effect. Therefore, it is urgent The need for a new solution to the above technical problems

Images