RU1786073C - Method and apparatus for blowing in blast furnace - Google Patents

Abstract

SUMMARY OF THE INVENTION: the method comprises loading coke, supplying hot material to the tuyeres and igniting coke in the lower part of the furnace by supplying oxygen for 1-5. min, after which compressed air is supplied around the circumference of the hearth to its peripheral part, remote from the walls of the hearth at a distance of 0.01-0.09 of the hearth diameter, depending on the initial flow rate of hot blowing. The blast furnace blower includes a loading system, blowing lances, a steel pipe located in the lower part of the hearth at the level of the cast iron notches with holes on its surface and nozzles installed in the pipe holes to the center of the furnace, the pipe is located around the hearth circumference, and the number of nozzles is equal to the number of tuyeres for supplying a blow. 2 ill.

Description

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The invention relates to the field of ferrous metallurgy, in particular to the production of pig iron in blast furnaces.

A known method of blowing a blast furnace using injection of compressed air or oxygen into a hearth through a pipe inserted into a cast iron notch. As a result of applying the method, the blowing time is reduced due to the intensification of the hearth heating.

Closest to the invention. In terms of its technical nature and the achieved result, there is a method of blowing a blast furnace, which includes supplying heated blast through the consumed pipelines to the lower region of the furnace at points remote from the walls of the furnace at alternating distances of 0.1-0.2 and 0. 25-0.35 of its diameter. The application of the method reduces the time of blasting of the blast furnace ..

When blowing through flowing pipelines, they are intensively oxidized (at a hot temperature of 700-1000 C). When consumable pipelines are combusted, the burning center shifts up to the level of air tuyeres, while the coke heating time in the furnace decreases, and the lower part of the furnace remains unheated. When the melting products are lowered into the forge, the masonry experiences thermal shock, which reduces its service life. Since the consumable pipelines are directed toward the center of the hearth, only the central part is heated, and the periphery, through which the smelting products are predominantly lowered, remains unheated.

Known devices for blowing a blast furnace have the following disadvantages: the inability to uniformly heat the masonry before the arrival of the melting products

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and heating of the coke nozzle in the region below the tuyere level at the periphery of the furnace. These drawbacks do not allow accelerated blowing, and reduce the resistance of the furnace masonry.

The aim of the invention is to accelerate the blowing and increase the resistance of the masonry of the furnace .... - ..

The goal is achieved in that in a method comprising loading coke, blowing into tuyeres, igniting coke in the lower part of the hearth, according to the invention, igniting coke in the lower part of the hearth is carried out by supplying oxygen for 1-5 minutes, after which compressed air around the hearth circumference to its peripheral part remote from the walls of the hearth at a distance of 0.01-0.09 diameter of the hearth, depending on the initial flow rate of hot blast.

This goal is also achieved by the fact that the device including a loading system, blowing tuyeres and a steel pipe located in the lower part of the hearth at the level of cast iron notches with holes on its surface, according to the invention, is equipped with nozzles installed in the pipe holes to the center furnace, with the pipe located around the circumference of the hearth, and the number of nozzles equal to the number of tuyeres for blowing.

i The ignition of coke in the lower part of the hearth allows accelerating the heating of the coke mass in the area under the tuyeres. The circumferential distribution of air around the walls of the hearth at the level of cast-iron notches allows you to quickly warm up the entire mass of coke located in the hearth below the level of air tuyeres due to rising up combustion products, which provides filtration of the melting products and accelerates the blowing. The oxygen supply for 1-5 min at the beginning of the blowing allows the ignition of a special material and the organization of a burning center in the lower part of the hearth under the tuyeres. The lower limit of the oxygen supply duration, 1 min, is due to the minimum necessary time for ignition of special combustible material. The upper limit of the duration of oxygen supply - 5 min - is due to the oxidation and fusion of pipes and nozzles. Subsequent supply of compressed air contributes to the organization of the burning center in the plane of the cast-iron notches and to uniform heating of the entire mass of coke located under the tuyere centers.

The supply of compressed air around the circumference of the hearth in its peripheral part, remote

from the walls of the furnace at a distance of 0.01-0.09 of the diameter of the furnace, it makes it possible to uniformly warm the masonry of the furnace and accelerate the blowing. increases its durability.

Figure 1 is a diagram of a device for blowing a blast furnace; in Fig.2 - section aa in Fig.1.

The steel pipe 1 with holes is installed at the level of the cast iron notches along the circumference of the hearth and led into the cast iron notches 2. The nozzles 3 are installed in the holes in the holes, which are directed toward the center of the furnace. The number of nozzles is equal to the number of air tuyeres 4.

The location of the pipe and nozzles allows the formation of a coke burning center in the peripheral part of the hearth, which contributes to uniform heating of the hearth masonry, increase its resistance and accelerate blowing. ..

The invention is carried out as follows. The blast furnace with a volume of 1033 m3 after major repairs of the II category is equipped with the rest of the pipe located around the circumference of the walls of the hearth at the level of cast-iron notches. On the pipe nozzles are installed in an amount of 14 pieces, corresponding to the number of tuyeres. The nozzles are directed towards the center of the hearth and are located from the walls at a distance of 0.01-0.09 diameter of the hearth. Opposite each nozzle is a special combustible material. In the furnace load coke and blowing charge. The blast furnace is equipped with two cast-iron gates, through which oxygen and compressed air lines are connected to the pipe. Simultaneously with the supply of hot air to the tuyeres, oxygen is supplied to the pipe for 1-5 minutes, after which the oxygen supply is stopped and compressed air is supplied at a pressure of 6 tm

As a result of the implementation of this method of blowing blast furnaces, uniform heating of the coke mass in the area under the tuyeres along the entire circumference of the hearth was achieved, filtration of smelting products was ensured, which made it possible to reduce the time of blowing from 72 to an increase in the overhaul period.

Analysis of the test results of the blast furnace blowing method and the device for its implementation shows that its use, in comparison with the known methods, helps to speed up the blowing from 72 to 36 hours and increase the durability of the masonry of the furnace.

Claims (2)

Formula of the invention 1, A method for blowing a blast furnace, including loading coke, supplying hot material to the tuyeres, igniting coke in the lower part of the furnace, heating and so that, in order to accelerate the blowing and increase the stability of the masonry furnace furnace Coke is ignited in the lower part of the hearth by supplying oxygen for 1-5 min, after which compressed air is supplied around the circumference of the hearth to its peripheral part remote from the root walls at a distance of 0.01-0.09 hearth diameter, in 9it. 1 0 depending on the initial consumption of mountains of what to blow. 2. A device for blowing a blast furnace, including a loading system, blowing tuyeres and a steel pipe located in the lower part of the hearth at the level of cast-iron notches with holes on its surface, characterized in that the device is equipped with nozzles installed in the holes of the pipe to the center furnace, with the pipe located around the circumference of the hearth, and the number of nozzles equal to the number of tuyeres for supplying a blow. Fi c.l