Combustion heat supply method and device of medium and low temperature reduction rotary kiln

Abstract

The invention discloses a combustion heat supply method and device of a medium and low temperature reduction rotary kiln. The combustion heat supply method includes the steps that firstly, fuel gas and air are fed into a combustor of the rotary kiln through pipelines to maintain continuous open fire combustion; and secondly, pulverized coal is fed into the combustor through an air flow conveying method to be combusted for heat supply, the mass volume ratio of the pulverized coal to all the air introduced into the combustor is 1:5-8, and the volume ratio of the fuel gas to all the air introduced into the combustor is 1:7-8. The device comprises a fuel gas introduction pipe, an air introduction pipe, a fuel introduction pipe, the combustor and a main inlet pipe connected with the combustor, wherein a fuel gas passage, an air passage and a fuel passage which are mutually independent are arranged in the main inlet pipe; the fuel gas introduction pipe is communicated with the combustor through the fuel gas passage; the air introduction pipe is communicated with the combustor through the air passage; the fuel introduction pipe is communicated with the combustor through the fuel passage. The combustion and heat supply method and device of the medium and low temperature reduction rotary kiln have the advantages that both good and bad coal can be used for combustion, is combusted sufficiently and does not die out, and production operation is safe and reliable.

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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