JPS5993807A - Top charging method of raw material to blast furnace - Google Patents

Abstract

PURPOSE:To prevent the deviation of the raw material to be charged over the circumference of a small bell in the stage of charging the raw material to a blast furnace by using two stationary hoppers, and adjusting the timing for opening the respective gate valves thereof according to the rotating angle of a swiveling chute. CONSTITUTION:A swiveling chute 9 begins to rotate from a stand-by position A upon receiving a command for starting, and when the chute arrives at a point B, the gate valve 3 of a stationary hopper 1 opens and a raw material falls onto a stationary chute 7. The time since the start B of the falling till the end C thereof is detected with a load detection sensor 7' and the position of the chute 9 is detected by a suitable means. The rotating speed of the chute 9 is calculated from the detected time and the information on the position, and the timing for opening the gate valve is so set that the gate valve 4 of the other stationary hopper 2 opens to permit fallig of the raw material onto the chute 8 when the chute 9 comes to the position D deviated by 180 deg. from the position B. The circumferential deviation of the raw material deposited around the small bell 1 is thus minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for charging raw materials at the top of a blast furnace (including shaft furnaces), and in particular, is a development result for appropriately adjusting the distribution of the top charge. The raw materials to be charged into the furnace are stored in a fixed hopper using a charging belt conveyor, and then charged into the furnace via a rotating chute → part of a small bell hopper → a 4% dog bell hopper. The rotating chute is expected to have the function of uniformly distributing the raw material discharged from the stationary hopper around the furnace top.

By the way, the rotating chute rotates for about 2 to 8 times during one charging operation, and the number of turns varies depending on the raw material discharge time and the rotating speed of the rotating chute. This results in an imbalance in the amount of raw material deposited on the circumference.

For example, when the rotating chute finishes discharging the raw material during 2.5 turns, the rotating chute will go around half the small bell 'f: 3 degrees, and the remaining p half way around 2 degrees. , the raw material for each half-circumference mother VCS revolution and two revolutions of the small bell is deposited, and such non-uniform deposition is due to the fact that the raw material is charged in the process of charging from the small bell to the large bell and then into the furnace. This invention is particularly designed to eliminate the wide range of bias that extends over half the rotation, even if it is smoothed to some extent. Using a hopper,
By adjusting the timing at which the gate valve provided at the top of the bell is opened according to the rotation angle of the rotating chute, the charged material can be distributed unevenly over the circumference of the small bell. The purpose is to prevent

Figure 1 shows a complete illustration of a furnace top charging device suitable for application of the present invention. In the figure, 1.2 and 2 fixed hoppers are shown, and 3.4+ indicates each solid hopper 1.2 and 9 independent. A gate valve that opens and closes 5 and 6 gate valves 3.4, a seal valve that opens before opening and closes after closing, 7.8 gate fixed chute, and 7' and 8' are load detection sensors. , 9 rotating chutes, 10 a small bell hopper, and 11 a small bell; the large bell is not shown.

In this invention, deviation of the charge over the circumference of the small bell is prevented as follows.

(First, raw materials to be charged into the blast furnace are transported to the top of the furnace by an ordinary charging conveyor (not shown? Omitted) and stored in the two fixed hoppers 1 and 2 shown in Fig. 1. Next, the fixed hoppers 1 Through the gate valves 3 and 4 provided in each of the two, the seal valves 5 and 6 reach the fixed chute 7.8, and the small bell is distributed by turning in the swing chute 9.
- Since the charging valve 3 and the bottle are normally opened and closed at the same time, if the number of turns of the rotating chute 9 is not an integer each time the raw material is charged, the It is unavoidable that the raw material accumulation will become uneven and the charge distribution will become uneven.

In order to avoid this deviation, there is a method of controlling the rotation speed and the rdJ at the time of discharging the raw material so that the number of revolutions of the rotating chute becomes exactly an integer each time the raw material is charged.

However, this method requires one expensive automatic opening side, and the above-mentioned measures alone are still insufficient because it changes depending on factors that make it difficult to always keep it on the side, such as the raw material discharge time and the particle size of the charged raw material. It is.

This development ψj is an attempt to reduce the bias in the charge distribution by a very simple method.Q, gate valve 3.
By simply controlling the opening timings of 4 in the following manner, uniform material deposition on the small bell can be achieved.

That is, the swinging chute 9 first starts rotating from the standby position A shown in FIG. The raw material begins to fall into the fixed chute 7.

Here, the time from the start B of the fall to the end C is determined by, for example, a load detection sensor 71 provided on the fixed chute 7, and the position of the rotating chute 9 is determined by a sensor installed on the rotating chute drive device (not shown). Nine detections.

From these time and position information above, turn Sud (
6) Calculate the rotational speed and turn the opening tie of the gate valve 4 of the other fixed hopper 2 to point D in Figure 2 (180° from the previous falling start position B) using a timer etc. Adjustment is made so that the raw material falls into the fixed chute 8 by opening the gate valve 4 of the fixed hopper 2 when the chute 9 arrives.

The above is a method in which the raw material is loaded into the other fixed hopper after the raw material has been input into one fixed hopper, and as a result, the deviation of the amount of raw material fJ on the circumference at the small bell 11 is minimized. It is clear that it can be done.

The raw material in the other identification hopper 2 is fed into the fixed chute 8 by opening the gate valve 4, and the timing is limited to starting when the rotating chute 9 reaches position D, which is shifted by 18o0 from position B, where the preceding raw material starts falling. p. As mentioned above, there is no need to wait until the end of the input of raw materials from the fixed hopper 1, and an example of this is shown in FIG.

In FIGS. 2 and 3, the broken line indicates when the raw material does not pass through the rotating chute 9, and the solid line indicates the trajectory of the rotating chute 90 during the passage, using a spiral winding line for convenience of explanation. be.

As mentioned above, in this invention, ■What is the turning speed of the turning chute? Add 1lllJ■ The gate valves 3.4 of fixed hoppers 1 and 2 can be opened and closed independently, and by using a timer, etc., the position of the rotating chute at the start of raw material discharge from the two hoppers is 18.
By shifting the material by 0°, the bias in the amount of raw material deposited at the top of the blast furnace is minimized.0 The rotating chute rotates 2.5 times by simultaneously cutting and discharging raw materials from two fixed hoppers. As shown in Fig. 4 (a) K, the distribution of the amount of accumulation along the circumference on the small bell when the small bell was rotated was cut out sequentially from the identified homper 1.2 over one half circumference and the other half circumference of the small bell. When the chute is rotated for 92.5 laps, the deviation on the /J'l bell circumference is completely eliminated as shown in Figure 4 (b). In the case of simultaneous cutting and 180° shifted Ji [N-th cutting, the same relationship when the rotating chute is 2.75 turns is
That's it, n2g5 Figures (a), (b), Figure 6 (a), (
b) K As compared, in both cases, simultaneous cutting causes local deviation, and this deviation will be eliminated even if it is reduced slightly as it is charged into the furnace from the large bell hopper. It can be estimated that this is not possible.

However, when the cut is shifted by 1800, the circumference is uneven! 7 occurs symmetrically in two places and the range (angle) is narrow, so as the material is charged into the furnace from the large bell, the degree of deviation becomes much smaller than in the case of simultaneous cutting.

As described above, the present invention can be applied to blast furnaces that do not have a control device for the raw material cutting flow rate, rotating chute rotation speed, and in which the number of revolutions of the chute during one charging cannot be controlled. Unevenness in the amount of raw material deposited over ! 7 and can be significantly reduced by 4 and is effective 0

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a furnace top charging device; FIGS. 2 and 8 are explanatory diagrams showing embodiments of the present invention; FIGS. a), (b) and Fig. 6 (a), (b) show that the number of turns of the rotating chute is 2.5.
It is a comparison chart of the small bell top pile/stacking distribution between simultaneous cutting and force peak sequential cutting in each case of 2.25 and 2.75 times. Figure 1 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] 1 In order to adjust the charge distribution at the top of the furnace by rotating the rotating chute for the charged material cut from the two fixed hoppers, each gate valve that opens and closes the two fixed hoppers independently is set in advance. The position where the raw material falls from the opened gate valve to the rotating chute is detected by the rotation angle of the rotating chute, and the raw material falls from the other gate valve at the position where the rotating chute has rotated further half a turn from the above raw material falling position. Top charging method of blast furnace raw material consisting of full starting Q