Efficient circular device and method for denitration of cement kiln

Abstract

The invention relates to an efficient circular method for denitration of a cement kiln. The method comprises the following steps: a part of flue gas, the discharge temperature of which is 300-350 DEGC, at a kiln tail outlet (1) into a waste heat boiler (2) for heat exchange and the other of the flue gas enters a second air outlet pipe (11); after heat exchange, the flue gas in the waste heat boiler enters a raw material mill (3) to heat and dehumidify raw materials and then is mixed with high-temperature flue gas in the second air outlet (11) to enter a deduster (4) for dedusting; the dedusted flue gas enters an SCR denitration reactor (6) through an ammonia spraying grating (5) for denitration treatment; a denitrated product is introduced into a water feeding coal saver (7) to heat fed water of the coal saver, and the heated fed water is discharged from a water outlet (7b) to the waste heat boiler (2) for recycling; and the flue gas after heat exchange is extracted by an induced draft fan (8) to a chimney (9) to be discharged. The efficient circular method has the advantages of being energy-saving and efficient in circulation, and reducing the flue gas discharging temperature, reducing the dust blocking risk, decreasing the occupied area and improving the denitration efficiency.

Description

technical field [0001] The invention relates to the technical field of cement kiln flue gas denitrification, in particular to a high-efficiency circulation cement kiln denitrification device and method. Background technique [0002] At present, the process flow of the existing cement kiln denitrification technology is generally as follows: the flue gas is drawn from the outlet of the cement kiln tail, the temperature is about 300-350 °C, the flue gas enters the settling chamber after pre-dust removal, and then enters the high-temperature electrostatic precipitator. After the flue gas is fully mixed with ammonia, it enters the SCR denitrification, and the nitrogen oxides are converted into nitrogen and water under the action of the SCR catalyst. The outlet is sent to the original waste heat boiler to recover heat through the induced draft fan. However, there are many problems in this denitrification method. When high dust is arranged, no dust collector is installed, so the pa...

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Problems solved by technology

[0003] The purpose of the present invention is to solve the problems of the existing cement kiln flue gas denitrification equipment, which are easy to block, occupy a large area, and have low recycling rate, and provide a high-efficiency circulation cement kiln denitrification device, which can not only reduce the exhaust gas temperature, Improve the energy saving effect, reduce the risk of dust clogging, reduce the occupied area, and improve the denitrification efficiency

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