SU1627561A1 - Method of furnace washing - Google Patents

Description

one

(21) 4618121/02

(22) 11/09/88

(46) 02.15.91. Bul № 6

(71) Kommunerskng Mining and Metallurgical Institute

(72) V.N. Dorofeev, A.G. Novokhlsky, GDMikhaylyuk, G.G.Vasyura,

V.A.Gordienko, S.I. Wooshin, E.V. Slobod nkzh and KLNikolaev

(53) 669.162.267.4 (088.8)

(56) Copyright with the form of i ielp i USSR № 1161360, cl. From 21 to 5/00, 1985.

Korobov I.I. Analysis of r-chOgi large domain furnaces. On Sat : Metallurgists and Coke chemistry, 1982, vol. 75, p. 102-106.

(54) METHOD FOR WASHING MOUNTAIN HORN DOMAIN FURNACE

(57) The invention relates to ferrous metallurgy and can be used on blast furnaces working with

blowing natural gas into air tuyeres. The aim of the invention is to reduce the consumption of coke, increase the productivity of the furnace and gas turbines of the air tuyeres by gasifying coke breeze and sketching in the furnace and improving its drainage capacity. In this case, the flow of free gas in groups of groups will be used to sensitize tuyeres, including 10–20% of all tuyeres and p1 arranged symmetrically with respect to the cast-iron notch, periodically with a period early 0.1–0.2 times between outlets, shortening 5–100%. The reduction of the consumption of natural gas is carried out in groups, starting from the iron notch in the direction of the opposite side of the blast furnace. About 0 shchl L rasskhod natural ha wasp) at the stove with J. OM. 1 ill., 1 tab.

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(ABOUT

The invention relates to ferrous metallurgy and can be used on blast furnaces working with blowing natural gas into air tuyeres.

The aim of the invention is to reduce coke consumption, increase furnace productivity and life of air tuyeres by improving gasification of coke breeze and graphite sang in the furnace and increasing its drainage capacity by periodically increasing the oxidation potential in the tuyere zones.

The method of washing the forge is illustrated in the drawing.

The method is carried out as follows.

Upon detection of the first signs of blockage of the furnace in the area of the cast-iron tap-hole, at the time of completion of the release of smelting products by 10-20% air, the consumption of natural gas is reduced for a period of 0.1-0.2 times between the end of exhaust (Ј), while maintaining the total consumption natural gas to the furnace constant. Tuyeres, which have reduced the consumption of natural gas, should be located symmetrically relative to the iron notch.

After the regulation time, the consumption of natural gas for these

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the tuyeres are returned to their previous level, and the reduction of the flow rate of the propellant gas is carried out to the next group, covering 10–20% of air tuyeres, spaced evenly to the left and right of the cast-iron notch in the direction from the cast-iron notch to the diametrically opposite side of the furnace. After the adjustment time expires, move to the next group of air tuyeres, etc.

The adjustment cycle begins at the moment when the iron production is completed, and I finish at the end of the next production of smelting products.

During the entire adjustment period, the total natural gas consumption per furnace is kept constant.

The natural gas consumption control pulses are alternately repeated for groups of air tuyeres until the gasification of coke breeze and graphite sang is complete and the signs of blockage of the hearth of the blast furnace disappear.

Reducing the consumption of natural gas allows an increase in the oxidation potential in the tuyere zone, which intensifies the gasification of coke breeze and graphite sang due to the secondary reduction of elements oxidized in the tuyere zones.

Reducing the consumption of natural gas by 50-100% alternately for a number of groups that include the Y-20% into one group of air tuyeres with a regulation period of 0.1-0.2 times between releases of smelting products, ensures efficient gasification of coke breeze and graphite dust and avoids the suspension of charge materials.

The sequence of adjusting the tuyere group in the direction from the cast-iron notch to the diametrically opposite side of the furnace ensures the creation of optimal drainage conditions that allow the maximum output of smelting products from the furnace during the time of production.

A 100% reduction in the consumption of natural gas for a group of tuyeres permits intensive gasification of coke breeze.

Reducing the reduction in natural gas consumption by less than 50% does not ensure the proper efficiency of gasification of coke breeze and graphite specimen.

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A period of adjustment of 0.1-0.2 times between releases of smelting products avoids suspending charge materials and provides gasification of coke breeze to graphite sang.

An increase in the adjustment period of more than 0.2 time between the end of the release of smelting products leads to the suspension of charge materials as a result of an excessive increase in the temperature in the furnace.

A reduction in the adjustment period of less than 0.1 time between the end of the release of smelting products does not allow for the intensive gasification of coke breeze and graphite spel because of the short exposure time.

Covering one group of 10–20% air lances avoids the suspension of charge materials while reducing the consumption of natural gas.

Example. The method of washing the hearth of a blast furnace was tested on a blast furnace with a volume of 1,386 m3, containing pig iron. The domain oven is equipped with 20 air lances. The oxygen content in the blast was 28.5%, the consumption of natural gas but a blast furnace was 1 1800 m3 / h.

The blast furnace showed signs of blockage of the furnace due to the accumulation of coke breeze and graphite sang in the furnace. At a given temperature, the blast furnace workers increased the amount of residual slag with each release, the duration of production increased, the furnace stroke decreased, and the air tuyeres began to burn.

To gasify coke breeze and graphite sang, they alternately reduced the consumption of natural gas into groups of air tuyeres. The procedure for reducing the consumption of natural gas for air tuyeres and the duration of the adjustment time is shown in the graph. At the same time, natural gas consumption was reduced by 20% of air tuyeres (4 air tuyeres). The time for stopping the supply of natural gas to one tuyere group was 0.2 times between releases of smelting products, or 0.5 h (30 min). The time between releases was Ј 2.5 hours. The reduction of gas consumption for tuyeres is 100%.

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At the time of the end of the production, the consumption of natural gas was reduced by 4 air tuyeres, located symmetrically relative to the cast-iron notch. After a time delay of 0.2 T, the gas flow rate for air tuyeres nos. 1, 2, 19, 20 was returned to the previous level (the natural gas consumption per lance was 590 me / h).

After that, the consumption of natural gas was reduced by a time of 0.2 ° C, followed by restoration to the previous level in the next neighboring group of tuyeres, located symmetrically with respect to the cast-iron notch, in the direction from the cast-iron notch to the diametrically opposite side of the furnace, i.e. on air lances № 3, 4, 17, 18.

Then, the consumption of natural gas was reduced by a time of 0.2, followed by restoration to the level of the city of Ripetto on the group of air tuyeres N 5, 6, 15, 16.

The following reduction in the consumption of natural gas with a duration of 0.2s was carried out on air lances N 7, 8, 13, 14. We completed the washing cycle of the hearth with air lances N 9, 10, 11, 12.

After the first cycle of oxygen washing, the operation of the hearth of the blast furnace was not fully stabilized. In order to fully stabilize the operation of the blast furnace, another cycle of the forge was carried out.

While reducing the consumption of natural gas to the groups of tuyeres, the total consumption of it for the remaining air tuyeres was maintained at a predetermined level (11,800 m3 /

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The table shows the test results of the proposed method for the boundary, average, above the upper, below the lower limits of the numerical values that are in the claims.

The proposed method of washing the blast furnace blast furnace effectively gasifies coke breeze and graphite spelling, improves drainage conditions in the furnace, thereby increasing furnace productivity, reducing coke consumption, and reducing the frequency of air tuyeres.

Claims (1)

Invention Formula The method of washing the hearth of a blast furnace, including reducing the consumption of natural gas, is different from that in order to reduce the consumption of coke, increase the efficiency of the furnace and the service life of air tuyeres by gasification of coke sword and graphite sang in the furnace, reducing the consumption of natural gas gas is carried out alternately in groups of air tuyeres with a period of 0.1-0.2 time between releases of smelting products, with one group of tuyeres including 10-20% of all tuyeres, and reducing the consumption of natural gas by 50-100% symmetrically is located dix groups tuyeres in the direction of the taphole to the diametrically opposite side of the furnace, the consumption of natural gas in the furnace is maintained constant. 0 The intensity of gasification of coke breeze is low. Drainage conditions are normalized very slowly. The limits of regulation are understated. Oh, 1C ten 50  1.0 o.t 0.6 oh h 0.2 t 1 3 3 g 5 6 7 9 9 10 11 it 13 H 1S f6 1 18 Iff Зо { cast iron chtnnai Letsa / Got # 1 /one Progress table The drainage conditions are improved, the productivity of the furnace increases, and the combustion of air tuyeres stops.