System and method for producing cement clinker through full-oxygen combustion circulating preheating

Abstract

The invention provides a system and method for producing cement clinker through total oxygen combustion circulation preheating. The system comprises preheaters, a decomposing furnace, a smoke chamber, a rotary kiln and a cooling machine, the preheaters comprise a conventional preheater and a smoke circulation preheater, and the cooling machine comprises a first cooling area and a second cooling area, the first cooling area comprises a first cooling subarea and a second cooling subarea, mixed gas of high-concentration pure oxygen and carbon dioxide flue gas is introduced into an inlet of the first cooling subarea, an outlet of the first cooling subarea is in communication with an air inlet of the rotary kiln, first cooling gas discharged from the outlet of the first cooling subarea serves as secondary air to enter the air inlet of the rotary kiln, carbon dioxide flue gas is introduced into an inlet of the second cooling area, an outlet of the second cooling area is in communication with the air inlet of the rotary kiln through a first pipeline, second cooling gas discharged from the outlet of the second cooling area is controlled to serve as quartic air to enter the air inlet of the rotary kiln, therefore the concentration of O2 in mixed gas in the rotary kiln is adjusted, and then the flame temperature of oxygen-fuel combustion of the rotary kiln is controlled.

Description

technical field [0001] The invention belongs to the technical field of cement technology, and in particular relates to a system and method for producing cement clinker by preheating in an all-oxygen combustion cycle. Background technique [0002] With the global warming, the emission of carbon dioxide has been widely concerned. The cement production process will produce a large amount of carbon dioxide. According to statistics, the production of 1 ton of cement will emit 0.6 to 0.7 tons of carbon dioxide. Carbon dioxide in cement kiln exhaust gas mainly comes from the following two aspects: [0003] 1. The carbon dioxide generated in the flue gas of fuel combustion accounts for about 40%. [0004] 2. The carbon dioxide produced by the decomposition of carbonate in raw materials accounts for about 60%. [0005] The "2050 Cement Technology Roadmap" jointly developed by the International Energy Agency (IEA) and the Cement Sustainability Initiative (CSI) points out that carbo...

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Problems solved by technology

[0017] In order to overcome the defects of the prior art, the present invention provides a system and method for producing cement clinker by oxy-fuel combustion cycle preheating, which solves the problem of the existing oxy-fuel combustion technology of the cement kiln. 2 / CO 2 O in the mixture 2 The concentration is not easy to adjust, so it is impossible to control the flame temperature of the oxy-fuel combustion of the rotary kiln, and the combustion flame temperature in the rotary kiln is too high, and the inner lining is easily damaged

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