Cement kiln waste heat utilization system based on high-temperature SCR device

Abstract

The invention discloses a cement kiln waste heat utilization system based on a high-temperature SCR device. The cement kiln waste heat utilization system comprises a kiln head production subsystem connected with a discharge port of a cyclone preheater and a kiln tail flue gas treatment subsystem connected with a smoke exhaust port of the cyclone preheater. The kiln head production subsystem and the kiln tail flue gas treatment subsystem are connected through a heat storage subsystem; the kiln tail flue gas treatment subsystem comprises a kiln tail waste heat boiler connected with the smoke outlet, and the kiln tail waste heat boiler is connected with a high-temperature SCR device through a kiln tail cyclone dust collector; the high-temperature SCR device is connected with the settling chamber through the heat storage subsystem; according to the high-temperature SCR device, the content of dust in flue gas entering the high-temperature SCR device can be greatly reduced, the serious influence of the dust on a catalyst in the high-temperature SCR device is reduced, meanwhile, the high-temperature SCR device can be used for replacing a traditional medium-temperature SCR device, and the flue gas denitration cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of cement kiln waste heat utilization, and in particular relates to a cement kiln waste heat utilization system based on a high-temperature SCR device. Background technique [0002] The SCR device is the core device of the flue gas treatment technology. Its function is to inject the reducing agent (ammonia / urea) into the flue gas, and selectively remove the NO in the flue gas under the action of the catalyst. x reduced to N 2 and H 2 O. SCR devices are divided into high-temperature SCR devices, medium-temperature SCR devices and low-temperature SCR devices, where "high temperature", "medium temperature" and "low temperature" refer to the temperature of the flue gas being processed. [0003] In the flue gas treatment of cement kilns, the flue gas in the kiln tail process is usually treated. The temperature of the flue gas discharged from the preheater is usually around 320-350 °C, and the high temperature ...

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Problems solved by technology

[0004] However, on the one hand, the flue gas temperature after passing through the high-temperature electrostatic precipitator will drop to about 280°C, and the temperature drop will reduce the reduction effect of the high-temperature SCR device; on the other hand, the dust removal effect of the high-temperature electrostatic precipitator is poor, resulting in The dust concentration in the flue gas of the high-temperature SCR device exceeds the standard. When the flue gas with a dust concentration exceeding the standard passes through the catalyst layer, due to the large alkaline content, small particle size and high viscosity of the flue gas dust, the vanadium-titanium denitrification catalyst in the high-temperature SCR device Serious impacts (such as catalyst clogging or poisoning, etc.), leading to a reduction in the out-of-stock effect of high-temperature SCR devices, and the emission of cement kiln fumes are not up to standard, and eventually cause environmental pollution

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