Device and method for cooling clinker by liquid oxygen and liquid nitrogen of cement kiln

Abstract

The invention discloses a device and a method for cooling clinker by liquid oxygen and liquid nitrogen of a cement kiln. The device is characterized in that a high-temperature cooling region of a grate cooler of the cement kiln is provided with a liquid oxygen input connector, and a middle-temperature cooling region of the grate cooler is provided with a liquid nitrogen input connector. The method comprises the steps of adding liquid oxygen the volume of which is 1%-12% of the total volume of cooling air fed by an air blower of a high temperature section of the grate cooler of the cement kiln, and adding liquid nitrogen the volume of which is 1%-45% of the total volume of cooling air fed by an air blower of a middle temperature section of the grate cooler of the cement kiln. The device and the method provided by the invention have the advantages that the cooling rate of clinker is improved by inputting liquid oxygen, and high-temperature clinker is cooled suddenly, so that the decomposition of D3S at 1250 DEG C is prevented or alleviated, the crystallization of MgO is prevented or alleviated, and the stability of the clinker is improved; a C3S crystal is prevented from growing, and thus the grindability of clinker is improved; the C2S crystal transfer is effectively prevented or alleviated by introduced liquid nitrogen.

Description

technical field [0001] The invention relates to the field of oxygen-enriched combustion in cement kilns, in particular to a device and method for cooling clinker by using liquid oxygen and liquid nitrogen in a cement kiln. Combustion apparatus and methods. Background technique [0002] Oxygen-enriched combustion refers to combustion in oxygen-enriched air with a higher oxygen concentration than air (20.9% oxygen): it is a highly efficient and energy-saving combustion technology, and it is used in the glass industry, metallurgical industry and thermal engineering fields. Usually there is only 20.9% oxygen in the air. When the fuel is burned in air, the calorific value will be reduced due to lack of oxygen, resulting in energy waste: when the oxygen concentration of coal (including oil products and natural gas) is 26% to 31%, the best combustion efficiency is obtained. . The mechanism of oxygen-enriched combustion is to send high-concentration oxygen into the combustion equi...

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Problems solved by technology

In addition, the rotary kiln clinker in the middle temperature section of the grate cooler also needs to solve the C 2 The problem of crystal transformation of S, especially in the production of high C 2 For S clinker products, it is more necessary to use rapid cooling to make the clinker quickly pass through the crystal transformation temperature range, so the cement kiln is equipped with a clinker cooling section, the purpose of which is to cool the high temperature clinker to improve the above-mentioned However, the current cooling section uses a high-power air-cooled machine that uses natural air, and with the change of ambient temperature, there are problems of high cooling energy consumption and unstable cooling effect, which in turn affects the quality of cement products.

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