Shaft furnace air intake device and shaft furnace air intake method

Abstract

The invention provides a shaft furnace air intake device and a shaft furnace air intake method. The device comprises a gas circular pipe, a gas hole, a reduced gas conveying and processing system, a detecting and control system, a bottom air intake pipeline, a gas distributor, a protective cover, a dust blowing facility and a gas separation facility, wherein the gas circular pipe and the gas hole allow air to enter from the middle of a shaft furnace. The reduced gas conveying and processing system comprises a cold gas pipeline, a hot gas pipeline, a hot gas dust collector and a mixed gas pipeline. The detecting and control system comprises a cold gas thermometer, a cold gas flowmeter, a cold gas flow adjusting valve, a hot gas thermometer, a mixed gas thermometer and relevant control systems. According to the shaft furnace air intake device and the shaft furnace air intake method, the reduced gas is conveyed into the central area of the shaft furnace reliably and efficiently, the flow and temperature of the reduced gas are controlled independently according to practical production demands, so that the gas flow in the shaft furnace is evenly distributed, the temperature fields are reasonably distributed, accordingly the metallization ratio of sponge iron is increased, the gas utilization rate of the shaft furnace and the production efficiency are improved, and the fuel ratio of the shaft furnace and the production cost are lowered.

Description

technical field [0001] The invention relates to a shaft furnace used for non-blast furnace ironmaking, and in particular to a shaft furnace intake device and a method for realizing shaft furnace intake by using the shaft furnace intake device. Background technique [0002] For shaft furnaces commonly used in non-blast furnace ironmaking, such as Midrex shaft furnace, HYL shaft furnace, and Corex shaft furnace, the reducing gas passes through the gas ring pipe arranged in the middle of the shaft furnace and the gas holes connected to it and uniformly distributed along the shaft furnace circumferential direction. into the shaft furnace. With the increase of the diameter of the shaft furnace, it is difficult for the reducing gas to reach the central area of ​​the shaft furnace from the peripheral area of ​​the shaft furnace, and the distribution of the gas in the cross section of the shaft furnace is uneven, resulting in a lower metallization rate of sponge iron in the central ...

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Problems solved by technology

From the perspective of production practice, although the AGD pipeline has some effects on improving the gas distribution in the shaft furnace, there are still some problems and deficiencies: it is difficult to manufacture and the cost is high; it is longer and wider, accounting for 30% of the cross-sectional area of ​​the shaft furnace, The utilization rate of the shaft furnace is reduced; water cooling is required, which poses a safety risk and also affects the temperature distribution in the furnace; the flow and temperature of the reducing gas entering the central area of ​​the shaft furnace through the AGD pipeline cannot be individually controlled, making it difficult to meet production needs

The device and method have the following problems and defects: the small holes on the side wall of the gas distribution device and the top of the cone are in direct contact with the charge used in production, the charge is tightly covered around the small hole, and the reduced gas entering the charge through the small hole has no space for maneuvering. It is difficult to diffuse, the contact area between the reducing gas and the charge is small, and the gas distribution effect is limited; due to the fluctuation of the pressure of the reducing gas, the pressure of the charge column, and the unavoidable local high temperature during production, these small holes are easily covered by the charge and Dust is clogged, which makes the gas distribution device invalid; the temperature of the reducing gas entering the shaft furnace is generally 800-850°C. Setting a gas regulating valve on such a high-temperature gas pipeline will cause problems in equipment selection and long-term stable operation of the equipment. Difficult to implement in actual production; failed to propose a method to control the temperature of the reducing gas entering the central area of ​​the shaft furnace through the gas distribution device according to the actual production needs

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