Low-CO2 partial pressure environment cement sintering system and cement clinker preparation method

Abstract

The invention discloses a low-CO2 partial pressure environment cement sintering system and a cement clinker preparation method, and belongs to the technical field of cement production equipment. The low-CO2 partial pressure environment cement sintering system comprises a smoke chamber, a rotary kiln, a grate cooler, a decomposing furnace, a carbon dioxide capturing and purifying system, a waste heat utilization system, a multi-stage pure oxygen preheater and a multi-stage air preheater, wherein the smoke chamber, the rotary kiln and the grate cooler are communicated in sequence; a high-temperature area of the grate cooler comprises a first cooling area and a second cooling area which are mutually independent, the first cooling area is communicated with the rotary kiln and a tertiary air pipe, and the second cooling area is communicated with the multi-stage air preheater through an air supply pipe; the multi-stage pure oxygen preheater is communicated with the decomposing furnace, the air supply pipe and the carbon dioxide capturing and purifying system; and the multi-stage air preheater is communicated with the decomposing furnace, the smoke chamber and the waste heat utilization system. A low-CO2-concentration and high-temperature low-CO2 partial pressure environment can be formed in the air supply pipe, hot raw materials can be further decomposed in the air supply pipe, and then the CaCO3 decomposition rate can be increased without increasing the temperature of the decomposing furnace.

Description

technical field [0001] The invention relates to the technical field of cement production equipment, in particular to a cement firing system in a low CO2 partial pressure environment and a cement clinker preparation method. Background technique [0002] The cement kiln firing system is generally used in the current cement production process. The cement kiln firing system is specifically composed of a cooler, a burner, a rotary kiln, a cyclone preheater, and a connecting air duct. Among them, the raw meal is preheated in the cyclone preheater and then decomposed in the calciner. Part of the fuel is burned in the calciner to provide the heat required for the decomposition of the raw meal. The decomposed hot raw meal is sent to the rotary kiln for another A part of the fuel is calcined and the hot raw meal is converted into cement clinker, and then the cement clinker is sent to the cooler, and the temperature is gradually reduced to an appropriate temperature under the cooling o...

AI Technical Summary

Problems solved by technology

However, no matter whether the above cement kiln system is fed with air or pure oxygen, the CO in the decomposition furnace 2 Concentrations will be high, resulting in CO 2 The partial pressure is high, and CaCO 3 Decompose to produce CO 2 is a reversible chemical reaction, when CO 2 When the partial pressure is high, the reaction in the decomposition furnace will decrease accordingly, and the CaCO 3 The decomposition rate will be affected, and want CaCO 3 As the decomposition rate of CaCO increases, it is necessary to increase the temperature in the decomposition furnace, and according to experiments, if you want to make CaCO 3 The decomposition reaches about 92%, and the temperature in the decomposition furnace needs to be increased by 100-200 degrees on the basis of the existing temperature

Increasing the temperature and the gas temperature at the outlet of the decomposition furnace will not only increase the heat consumption of the entire system, but also increase the gas temperature of the cyclone at the bottom end accordingly, and high temperature will cause skinning on the cyclone and material pipe, and will also Increase the exhaust gas temperature at the outlet of the preheater, which in turn affects the production effect of the entire cement kiln system

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