SU1723429A1 - Furnace of stepped suspension layer - Google Patents

Abstract

This invention relates to the preparation of raw materials in the steel industry. The purpose of the invention is to increase productivity and reduce energy costs. Intensification of the heat treatment of the material is provided by using a furnace of a step-weighted layer consisting of a chamber with inclined walls and a stepped hearth, equipped with tuyeres mounted at an angle to the unloading side of the material. The angle of inclination of the side walls of the chamber is set to 71-87 °, and the angle of inclination of the transporting tuyeres is 55 + K (87a), where a is the angle of inclination of the walls, degrees; , 5-2,0 - proportionality coefficient. At the specified ratio of the angles of inclination of the side walls of the tuyeres, optimal conditions are obtained for the heat treatment of the ore-coal mixture. 2 Il.

Description

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The invention relates to the preparation of iron ore in ferrous metallurgy, in particular to the construction of aggregates for the magnetising roasting of iron ores.

The aim of the invention is to increase productivity and reduce energy costs.

FIG. 1 shows a stage-weighted layer furnace; in fig. 2 shows section A-A in FIG. one.

The furnace consists of a chamber 1 with inclined walls 2 stepped hearth 3, equipped with inclined tuyeres 4, directed in the direction of unloading material.

The furnace works as follows.

The mixture of ore and solid reducing agent (coal) is loaded into chamber 1 and successively in a suspended state are transferred from step to step by high-speed transport jets, which are formed in tuyeres 4 and blown into chamber 1. As

advancing the hearth 3, the angular charge is successively dried, heated and partially reduced. After that, the ore is reloaded into the chamber with a loose layer and subjected to final recovery.

The angle of inclination of the side walls of the furnace chamber of the step-weighted layer is set in the range of 71-87 ° C to the horizon. If the angle of inclination of the walls is less than 71 °, then due to the low location of the flow of the material being transported, a decrease in the intensity of the heat treatment process occurs, and the productivity of the furnace decreases. When the angle of inclination of the walls is more than 87 °, the performance of the furnace approaches the performance of the furnace with vertical walls, i.e. the equipment durability decreases, the productivity of the furnace and the adjustment of the angle of inclination of the transporting tuyeres becomes unnecessary.

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The angle of the tuyeres is determined by the ratio

0 55 + K (87-a),

where a is the angle of inclination of the chamber walls, hail;

, 5-2,0 - proportionality coefficient.

As the angle of inclination of the tuyeres, starting from 55 ° to the horizon, decreases by a smaller amount (less than 5 for each degree of decrease in the angle of inclination of the walls), the residence time of the material in the furnace decreases, including due to the decrease in the return value tuyeres, the charge does not reach the required temperature potential, and as a result either the product quality deteriorates or the furnace productivity decreases.

As the angle of inclination of the tuyeres increases by a large amount (more than 0 for each degree of decrease in the angle of inclination of the furnace walls), the heat flux increases from top to bottom, the mixture does not fully perceive it, in the lower part of the furnace areas with the same

thermal potential (idle sections), and the productivity of the furnace decreases.

The application of the invention improves the performance of the curing, the stability of the side walls and, accordingly, the reduction of the overhaul life of the furnace, reducing the consumption of natural gas for the redistribution.

Formula of the Invention The furnace of a step-weighted layer, comprising a chamber with inclined walls and a stepped hearth, a loading unit and transporting tuyeres installed in the hearth at an angle to the horizon and directed towards the discharge unit, characterized in that, in order to increase productivity and reduce energy costs, the angle of inclination of the side walls is set equal to 71-87 ° C, and the angle of inclination of the transporting tuyeres ft - 55 + K (87a), where a is the angle of inclination of the walls, 5-2.0 - proportionality factor.

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Claims (1)

Claim A step-weighted layer furnace containing a chamber with inclined walls and a stepped hearth, a loading unit and 15 transporting lances installed in the hearth at an angle to the horizontal and directed towards the unloading unit, characterized in that, in order to increase productivity and reduce energy costs , the angle of inclination of the side walls is set equal to 71-87 ° C, and the angle of inclination of the transporting tuyeres is β 55 + K (87-a), where a is the angle of inclination of the walls, K = 0.5-2.0 is the proportionality coefficient.