Method and system for preventing catalyst blockage

Abstract

The invention discloses a system for preventing catalyst blockage. The system comprises a longitudinal flue (2) and a transverse flue (3), wherein a dust gauze A (1) is arranged in the longitudinal flue (2); only one end of the dust gauze A (1) is movably connected with the longitudinal flue (2); a slide fastener rapping device A (4) is connected above the dust gauze A (1), and is connected with the dust gauze A (1); a dust hopper A (5) is arranged below the dust gauze A (1); an ash hopper lever meter (20) is arranged in the dust hopper A (5); and the lower end of the dust hopper A (5) is connected with a discharging device A (6). According to the system, dust particles of which the particle diameters are over 4 centimeters can be prevented from entering a catalyst layer, dust particles on the dust gauze can be discharged automatically under the condition of no stop of a boiler, and the system can run safely, efficiently and continuously at low pressure loss.

Description

technical field [0001] The invention relates to a selective catalytic reduction reactor protection method and device, in particular to a method and system for preventing catalyst blockage. Background technique [0002] During my country's "Twelfth Five-Year Plan" period, nitrogen oxide emissions were included in the binding index system for the first time, requiring a 10% reduction on the basis of 2010. Nitrogen oxides have become the focus of my country's "Twelfth Five-Year Plan" pollutant emission reduction. my country has promulgated the most stringent NOx emission standards in the world. Most coal-fired power plant boilers need to add denitrification devices. Due to the strict NOx emission standards in my country, most denitrification devices use the SCR method for denitrification. The principle of the SCR method is in the catalyst. If there is, NOx is reduced to N2 by spraying the denitration reducing agent ammonia into the reactor. The reaction temperature of this proc...

AI Technical Summary

Problems solved by technology

For flue gas denitrification in coal-fired power plants, the catalyst must operate in a high-ash environment. The catalyst is generally installed in a vertical flue, and the flue gas passes through the pores of the catalyst vertically downward. The finer ash will flow through the pores of the catalyst, and the smaller Large ash cannot pass through the catalyst pores, which makes the catalyst pores blocked

The consequences of catalyst pore blockage are firstly that the activity of the catalyst is reduced, and the blocked catalyst surface cannot contact with the flue gas and loses the reaction ability; secondly, after the catalyst pore is blocked, the pressure loss will increase, and the flow rate of the unblocked catalytic pore will increase sharply , long-term operation leads to catalyst wear failure or even collapse, which seriously affects the safe and stable operation of the unit

[0003] Common catalyst soot blowing methods are steam or sonic wave. These soot blowing methods are mainly aimed at the dust adhering to the surface of the catalyst, but cannot solve the problem of catalyst pore blockage

Generally, catalyst manufacturers will add a layer of grille above the catalyst to prevent larger particles of ash from clogging the catalyst. However, the result is that the grille will be blocked by large ash particles and cannot be removed online, thus increasing The pressure drop of the entire system brings higher energy consumption, and long-term operation will also lead to catalyst wear, failure or even collapse, seriously affecting the safe and stable operation of the unit

[0004] The interception of dust particles with a particle size of more than 4 cm through the filter screen can be found in Chinese invention patents CN101227406B and CN101517318A, but these filters and their cleaning technologies have the following disadvantages: the filter screen has a high flow velocity, and it is easy to be eroded and damaged under high dust conditions. The rapping device directly contacts the filter screen, which is easy to cause damage to the filter screen, and the mechanism of the vibration hammer is complicated, which is not conducive to daily maintenance and high cost

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