SCR (silicon controlled rectifier) denitration system of cement kiln gas

Abstract

The invention discloses an SCR (silicon controlled rectifier) denitration system of cement kiln gas. The SCR denitration system comprise an ammonia spraying device, a reactor box body, a wind evening rectifying device, catalysts and sound wave soot blowers, wherein the wind evening rectifying device and the catalysts are respectively arranged on the upper part and the lower part in the reactor box body; and the sound wave soot blowers are arranged in the reactor box body. The SCR denitration system also comprises an electrofilter and a mixing device, wherein the electrofilter comprises a gas inlet and a gas outlet; and the gas inlet of the electrofilter is provided with a gas inlet pipeline. The ammonia spraying device and the mixing device are respectively arranged on the gas inlet pipeline, the mixing device is positioned on the down stream of the ammonia spraying device, an exit of the electrofilter is connected with the upper end of the reactor box body by a gas collection cover, the lower end of the reactor box body is provided with a lower cone bucket, and the lower cone bucket is connected with a gas outlet channel. The SCR denitration system of the cement kiln gas is long in service life and low in use cost.

Description

technical field [0001] The invention relates to an SCR denitrification system for cement kiln flue gas. Background technique [0002] The existing cement kiln flue gas denitration technology is mainly based on low-nitrogen burner technology, air staged combustion technology and SNCR flue gas denitrification technology. Although SCR flue gas denitrification technology is mature and has been put into commercial operation, it is still in the cement industry. There are few applications, mainly because the nitrogen oxide emission requirements of the cement industry are relatively lower than those of the thermal power industry, and the cost of SCR flue gas denitrification projects is relatively high, especially the price of catalysts is relatively expensive. However, with the continuous improvement of national environmental protection requirements, the nitrogen oxide emission requirements of the cement industry will also become increasingly stringent, so SCR flue gas denitrificati...

AI Technical Summary

Problems solved by technology

The temperature of the conventional SCR denitrification reaction is 280-420°C. On the cement kiln, only the flue gas temperature in the section of the flue from the outlet of the cyclone preheater C1 cylinder to the entrance of the kiln tail humidification tower is suitable for the SCR denitrification reaction temperature, but here The dust concentration in flue gas is relatively high, normally at 100mg / Nm 3 around, and the flue gas contains a large amount of alkaline substances and heavy metal ions, such as CaO, K, Na, As, etc., which easily lead to catalyst poisoning and abrasion, greatly shortening the service life of the catalyst, thereby increasing the cost of use

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