Combustion heating method and device for medium and low temperature reduction rotary kiln

Abstract

A combustion heat supply method and device for a medium-low temperature reduction rotary kiln. The method is to first send gas and air to the burner of the rotary kiln through pipelines to maintain continuous open flame combustion, and then use the airflow conveying method to send coal powder into the burner Combustion heat supply, wherein the mass volume ratio of pulverized coal to the total amount of air passed into the burner is 1:5~8, and the volume ratio of gas to the total amount of air passed into the burner is 1:7~ 8. The device includes a gas inlet pipe, an air inlet pipe, a fuel inlet pipe, a burner and a main inlet pipe connected to the burner. The main inlet pipe is provided with independent gas passages, air passages and fuel passages, and the gas inlet pipe passes through The gas passage communicates with the burner, the air inlet pipe communicates with the burner through the air passage, and the fuel inlet pipe communicates with the burner through the fuel passage. The invention has the advantages that good or bad coal quality can be used for combustion, the combustion is sufficient without flameout, the production operation is safe and reliable, and the like.

Description

technical field [0001] The invention relates to the technical field of magnetization roasting of a rotary kiln, in particular to a combustion heating method and device for a medium-low temperature reduction rotary kiln. Background technique [0002] The rotary kiln is widely used in the fields of building materials, metallurgy, chemical industry, and environmental protection to process solid materials, and has the advantages of large processing capacity and continuous and stable operation. The operating temperature range of the rotary kiln is generally 300-1500°C, the combustion temperature of the cement kiln is above 1200°C, and the temperature is between 600-800°C in the magnetization roasting of low-grade iron ore in the medium-low temperature reduction rotary kiln, where natural gas resources are abundant Natural gas is generally used as the fuel in the region, and blast furnace gas or coke oven gas is used as the heat source in the concentrators near the steel mills, wh...

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Problems solved by technology

The operating temperature range of the rotary kiln is generally 300-1500°C, the combustion temperature of the cement kiln is above 1200°C, and the temperature is between 600-800°C in the magnetization roasting of low-grade iron ore in the medium-low temperature reduction rotary kiln, where natural gas resources are abundant Natural gas is generally used as the fuel in the region, and blast furnace gas or coke oven gas is used as the heat source in the concentrators near the steel mills, while most iron ore concentrators use coal as the main fuel, so there is a problem of coal quality Influenced by the combustion process, coal with good quality can be directly used for combustion and heating. However, in areas rich in lignite or firewood resources such as Yunnan and Xinjiang, from the perspective of cost saving, only local materials can be used to choose lignite or firewood as fuel

Lignite or wood coal is injected into the rotary kiln as fuel. At this time, the coal is in a semi-combustion state, and the burner is prone to flameout. When a small amount is injected, it can be burned, but the heat supply is insufficient, and the processing capacity cannot be increased; To the reaction - the role of fire pressure, resulting in flameout, and even safety accidents

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