SU1032019A1 - Method for charging blast furnace - Google Patents

Abstract

METHOD OF LOADING A DOMAIN FURNACE, including loading charge materials from skips to a distributor with its simultaneous rotation, characterized in that, in order to reduce coke consumption by increasing the use of energy of the gas stream while improving the district distribution of the charge in the colleague, simultaneously with the start of loading the charge of the skip, the angular rotational speed of the distributor is changed, increasing it during the first 30-42% of the time for the skip to completely empty from the initial setpoint to the maximum from following sksfosti maintaining constant rotation, the ratio of the maximum to the initial vra1chvni rate is 8-10 and the complete emptying of the skip valve is rotated one turn. .

Description

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The invention relates to ferrous metallurgy, in particular to methods for loading blast furnaces.

The known method of loading a blast furnace with a charge distributor operating at n stations (n 4, 6, 8, 12, etc.), the essence of which is that the loading of each regular supply of charge material at the point of the circle of the manhole is performed by successive rotation loaded distribution funnel at an angle of 360: n Cl.

The disadvantage of this method of blast furnace loading is increased coke consumption, due to the fact that the gas flow energy is not fully used for a long period of time. The reason for this is that the gas flow through the layer of the laid charge material is unevenly distributed due to the uneven distribution of the charge, since the uniform distribution of material on the furnace head is reached only after the distributor passes a closed feed cycle consisting of n stations.

The closest to the proposed nq technical essence and the achieved result is a method of loading a blast furnace, including loading charge materials from skips into a distributor with simultaneous rotation of the latter 2.

A disadvantage of the known method of charging a blast furnace is also an increased coke consumption due to the fact that the charge is not evenly placed in the distributor funnel. The uneven distribution of the material is due to the fact that the amount of material (by volume) entering the unit of time from the skip into the funnel of the distributor rotating at a constant angular velocity is unequal (as the material enters the funnel in an amount proportional to the skip slope). Therefore, the layer of charge

The material loaded into the distributor funnel in this way varies in thickness.

Another disadvantage of this method of loading a blast furnace is that when the charge distributor is rotated at a constant angular velocity, it is impossible to combine the end of the previously laid layer of the charge with the beginning of the loading layer. Therefore, the layers of material discharged from the skips are applied with each other, which does not allow obtaining the required degree of uniformity of the circumferential distribution of the Material in the distributor funnel.

The purpose of the invention is to reduce the consumption of coke by increasing the degree of energy utilization of the gas flow while improving the diicht distribution at the furnace top.

The goal is achieved according to the method of loading a blast furnace, which includes loading charge materials from skips to a distributor while simultaneously rotating the latter, simultaneously with the start of shedding charge from each skip, the angular rotational speed of the distributor changes, increasing it during the first 30-42% . the time of complete emptying of the skip from the initial setpoint to the maximum with subsequent maintenance of the rotational speed is constant, while the ratio of the maximum rotational speed to the initial one is 8-10, and during the complete emptying of the skip the distributor is turned one turn.

FIG. Figure 1 shows the charge loading scheme for a furnace with a useful volume of 1386 m. The skip slope is 6 m, the amount of material loaded into it is 5 m)} in FIG. 2 - depending - -f. (T)); u; -f, u)

for the same furnace.

The rotation drive of the charge distributor of this boot device must additionally be provided with an automatic transmission of a remote linking it to the skip tilt angle sensor.

Skips are charged with charge material and alternately fed by a sloping bridge to the top of the blast furnace. Since the bottom of the skip when it is loaded is at an angle to the vertical plane, the gaps surface in it is located at an acute angle to the bore (Fig. 1, plane A), when the skip reaches the loading curves, the angle of inclination of its bottom to the horizon changes. During the period when the plane passing through the edge of skip D and the upper zone of the surface of the mound C is at an angle to the horizon (3, equal to the angle of repose of the charge material, the charge begins to pour out of the skip (measurements on blast furnaces show that (L 28 - 32) Then, when the skip is rotated from the specified position, an amount of material between the DB and B planes is poured out of the skip at time at, (Fig. 1). The measurements taken on the blast furnace V 1386 m show that the angle changes according to the law shown in Fig. 2 (curve a 1), and the time it takes for the material to completely fall out of the skip is 7,5 seconds. At the same time, the rate of material dumping from the skip (q) is changed according to the law represented by curve 1 (Fig. 2).

In order to obtain a uniform circumferential distribution of the charge in the distributor funnel, it is necessary to vary the angular velocity of rotation of the latter (tw) proportionally to the change in the velocity of removal of the charge material from the skip. Therefore, the distributor drives the Buie before the charge is ejected from the skip and rotates at a constant minimum speed of 4-6 rad / min (this is necessary to reduce the moments for the full drive, since the moment of start of movement of the distributor shift 1,, 8 times the moments of frictional force during rotation). During the approach of the skip to the position in which the charge rashes from it begin, the automatic dispatch command is given by automatic remote transmission and the angular rotational speed of the latter (Uj) gradually increases until the velocity of the discharge q of the charge q approaches the maximum value. Then the rotational speed of the distributor is set at a constant (tU) (Fig. 2, curve 3) until the rate of skip from the skip (q) H.e starts to decrease sharply, then decreases to the initial value U),. Values of W) s. and, being chosen such that; during the complete emptying of the bale, the distributor turned on

integer revolutions, in this example, n 1 turn. At the same time, there is no need to combine the end of the previously laid layer of the charge with the initial pouring out of the skip at the moment. With regard to the blast furnace Vy, 1386 m dependence - / 5 (O; (t) and w "4l It) are presented in FIG. 2. -

Due to the fact that the angular rotational speed of the distributor is proportional to the rate of charge transfer

from a skip, in the distributor's funnel, in one revolution, an equally thick symmetrical layer of the charge material is laid about the furnace axis. This was confirmed by laboratory tests. The magnitude of the rotational speed of the distributor should be chosen to be no more than 5060 rad / min (8-10 rpm), since the power of the existing drives and the strength characteristics of the parts of typical distributors allow this mode of operation to be provided. To reduce the value (which is useful in terms of reducing drive power), it is necessary to reduce the skip tipping speed. This leads to an increase in skip emptying time, over which the distributor should turn integer a number of times, with less

Studies of the process of precipitation of the charge from the skip at nine domestic blast furnaces of various useful volumes showed that the outflow of material into the distribution funnel. The heat flow rate is uneven, and the flow rate (the second material consumption) during the tipping of the skip float increases smoothly, then it is set close to constant and remains so almost until the charge is completely drained from the skip. Moreover, the ratio of the length of time during which the rate of discharge of the charge (second consumption) varies from zero to the maximum steady-state value of t to the time of complete emptying of the skip ty

is 0.3-0.42 (i.e. t

100%

 ) and practically does not depend on the size of the skips used in furnaces of various useful volumes.

The application of the proposed method of loading a blast furnace makes it possible to improve the district distribution of the charge at the top and increase the performance of the CKCtevKi load r

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Claims (1)

METHOD FOR LOADING A DOMAIN FURNACE, including loading charge materials from the skips into the distributor with its simultaneous rotation, characterized in that, in order to reduce the coke consumption by increasing the energy use of the gas stream while improving the distribution of the charge in the furnace top, simultaneously with the beginning of the charge sintering from each skip, a change in the angular velocity of rotation of the distributor is made, increasing it during the first 30-42% of the time the skip is completely emptied from the initial set to the maximum with the last yuschim maintaining the rotation speed constant, the ratio of the maximum rotational speed to the original is 8-10, and for the complete emptying of the skip time on the distributor is rotated one revolution g.