JPS6191307A - Detection of descending of charge in blast furnace - Google Patents

Abstract

PURPOSE:To measure exactly the layer thickness distribution and descending speed distribution of the raw material charged into a blast furnace by providing movably in and out >=2 pieces of guide pipes to the blast furnace in the height direction thereof and measuring the load of the charge exerted to the weight attached by wires to the inside of the furnace through said pipes. CONSTITUTION:The plural guide pipes 3 are attached freely movably in and out at specified intervals through the wall 1 of the blast furnace in the height direction thereof and the wires 4 are passed into the pipes 3 from the outside of the furnace. The weight 5 is preliminarily attached to the top end of the wire. The weight 5 receives the load of the charged raw material 2 descending in the furnace and the downward force acting on the weight 5 is transmitted to a load converter 7 in a load detector 6 through the wire 4. The change in said force is detected as a strain output by a strain gage 8. Each pipe 3 is put in and out to change the position of the top end thereof from the furnace core to the furnace wall in the radial direction by which the layer thickness distribution and descending speed distribution of the charged raw material 2, i.e., ore, coke, etc., are detected exactly and the distribution of the charged raw material is adjusted to stabilize the furnace condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for accurately detecting the unloading of blast furnace contents.

(Prior Art) Recent dismantling surveys of blast furnaces have revealed that in the blast furnace where ore is reduced and melted, there is a region where the ore is in a semi-molten state (hereinafter referred to as the "cohesive zone"). By the way, the cohesive zone that exists in the furnace is the area with the greatest ventilation resistance from the perspective of gas flow, and its shape greatly affects the gas flow distribution within the furnace. Not only is this an area where the unloading conditions change greatly as the ore melts, but also the unloading of coke in the lower part of the furnace (the area below the cohesive zone) shows that the coke in the furnace core and the furnace wall profile are different from each other. Since the shape of the cohesive zone in the radial direction forms the boundary of the lower-furnace unloading area, the shape has a great influence on the lower-furnace unloading situation.

As described above, the radial position of the cohesive zone in the furnace is an important control item when operating a blast furnace.

Now, as a method of controlling the shape and position of the cohesive zone in the radial direction, a method is usually adopted in which the burden distribution at the top of the furnace is adjusted using a movable armor, etc. In addition to operable factors such as armour-notch, charge amount, and charge grain size, the distribution is also determined by the radial unloading distribution inside the furnace, the furnace conditions such as the top charge surface shape, gas flow distribution, etc. Furthermore, we will investigate the influence of factors that are currently difficult to accurately estimate, such as the phenomenon of coke flowing into the furnace core when ore is charged to the coke surface layer.
receive. Therefore, in order to accurately adjust the charge distribution, 1. ``It is necessary to adjust the above-mentioned operable factors and to grasp the actual charge distribution.

Therefore, various methods have been proposed in the past for actually understanding the ore/coke layer thickness ratio distribution in the radial direction within the furnace (hereinafter referred to as "layer thickness ratio distribution") and the unloading speed distribution. The main ones are shown below.

■ Estimation method using a layer top profile meter Sakunji to detect the stock level position is installed at multiple points in the radial direction, and the surface shape of the charge is measured for each charge, and the layer thickness ratio distribution and load amount are 9 velocity distributions. How to estimate.

■Method of using electrical resistance measuring sensors Taking advantage of the fact that the electrical resistance differs between the coke bed and the ore layer, electrical resistance measuring sensors are installed at two or more points in the height direction of the furnace, and the outputs of these sensors are measured over time. A method of determining the layer thickness and unloading speed of the charge from the

By installing such replacement senna at multiple points in the radial direction, the radial distribution of these amounts can be determined.

(JP-A-52-141257, JP-A-52-1516
06) ■Method using a magnetic sensor Taking advantage of the fact that the magnetic permeability is different between the coke layer and the ore layer, a sonde with a built-in magnetic sensor is inserted into the furnace wall brick or inside the furnace to separate the coke layer and the ore layer. The magnetic flux that occurs between
A method of measuring the change in ** at two or more points in the height direction of the furnace to determine the layer thickness of the charge and the unloading speed. and,
By placing such sondes at multiple points in the radial direction, a radial distribution of these quantities can be obtained. (4? 1983-84112) ■Method of measuring unloading load This method uses the fact that the load received by the water-cooled lance inserted into the blast furnace changes depending on the particle size of the unloaded charge. , equipped with a lance for measuring loads at two or more force points in the height direction,
A method of determining the layer thickness of the material in the furnace and the unloading potash rate by measuring the strain of the lance. ←Special application Sho 59-782
No. 18) (Problems to be Solved by the Invention) Each of the above nine methods has the following problems.

Φ Estimation method using layer top profile meter This method cannot capture changes in layer thickness ratio distribution after charging due to flow-in phenomenon. Since the output varies depending on the temperature and the moisture in the charge, there is a problem in that output fluctuations caused by this cause measurement errors.゛ ■Method using a magnetic sensor - In this method, the output of the magnetic sensor varies depending on the temperature of the charged material, which causes a difference in measurement A, but the charge in the furnace undergoes magnetic transformation. :Measurement cannot be performed at temperatures exceeding the temperature that causes the test.

■Method for measuring the unloading load This method is suitable for determining the layer thickness near the furnace wall and the unloading speed, but it cannot determine the layer thickness or unloading speed at a specific position in the radial direction. .

On the other hand, the molten M in the radial direction inside the furnace, which serves as a guideline for adjusting the burden distribution,
The estimation of the shape and position of the tube is based on the data on the radial gas temperature and gas composition distribution obtained from the sonde inserted and installed in the blast furnace shaft, and the radial distribution and unloading speed distribution of the charge. This can be done by making certain assumptions, by using the measured values from the various sensors mentioned above, or by inputting the results of other numerical simulations and performing reaction heat transfer calculations for each zone in the semicircular direction. ing.

As mentioned above, accurate understanding of the layer thickness ratio distribution and unloading speed distribution in the radial direction inside the furnace is an important control item for stable operation of the blast furnace. In order to accurately grasp the band shape,
This is also an important point in accurately performing control by adjusting the burden distribution.The present invention provides a distribution of the burden layer 11 that does not extend near the furnace wall, but extends to the middle part of the furnace and the furnace core. It is also possible to measure the unloading speed distribution.
Moreover, it is an object of the present invention to provide an accurate method for measuring the amount, which is not affected by the temperature or moisture content of the charged material.

That is, the present invention penetrates the wall of the blast furnace to provide V in the packed bed inside the furnace.
In this case, two or more guide pipes are inserted in and out at a required interval in the height direction of the furnace, and an M is attached to the tip of a wire that passes through these guide pipes and is guided into the packed bed in the furnace.
The unloading rate and layer thickness of the furnace contents are measured by measuring the load that the plow receives from the furnace contents descending in the furnace through the wire with a load detector attached to the rear end of the wire. This is a method for detecting unloading in a blast furnace.

Below, the method of the present invention will be explained in detail based on the attached illustrations.

FIG. 1 shows an example of equipment a for carrying out the method of the present invention), +11 is the furnace wall, (2+ is the furnace contents, (3
) penetrates the furnace wall (υ), and its tip side is the furnace contents [
2) A guide pipe provided to be located inside the wire (4) guided by the guide pipe (31).
is introduced into the furnace contents 121 from outside the furnace.

+5) is a weight that is attached to the tip of the wire 141, waits in the furnace, and directly receives the load of the falling furnace contents (2), and the load acting on this weight (5) is , wire 14) and is detected by a load detector (6) installed at the rear end of the wire (4).

The guide pipe (3) is configured to be able to move in and out of the furnace wall 111, so that the radial position of the weight (5) within the blast furnace can be changed.

To detect the unloading of a blast furnace using the above-mentioned device, the following procedure is performed.

■The nine-layered weight 5) suspended in the furnace receives a downward force from the furnace contents (2) falling around it. This downward force is a wire! 4I to the load converter 171, which is a component of the load detector (6), and the load converter 171 repeats deformation and recovery according to the force received by the weight in the furnace. This repeated change is extracted as an output fluctuation of strain by a strain gauge (81) installed in the load transducer +71. Fig. 2 shows an example of actual measurement of strain fluctuation.

The type of T/C of the load transducer 17) is not particularly specified, but it must be able to deform within the elastic limit with respect to the load received by the weight. Convert the values actually measured (second factor) into a set diagram as shown in Figure 3, and define the total sum within a certain time as the distortion and deformation integral value in the form shown in the formula 0 below. .

Strain deformation integral value 3 fax ... ■ Strain deformation integral value (1 minute integral value) defined by the above formula 0 when changing the unloading speed and burden particle size using a blast furnace model experimental device. The changes are shown in Figure 4. From Figure 4, even at the same unloading speed, strain deformation occurs due to the difference in grain size of the burden.In other words, coke, which is the charge in the furnace, and sintered ore, which makes up most of the ore layer, have different grain sizes. Since they are quite different (the average particle size of coke is approximately 50cm and the average particle size of sinter is approximately 25cm), it is possible to distinguish between the coke layer and the sintered ore layer using the detection method described above. .

■The particle diameter of the furnace contents 121 around the weight (5) changes over time as the coke and sintered ore layer passes, so the detected value a mentioned above is If two or more transducers are installed at a required interval in the horizontal direction, the strain deformation fractional value output from each load transducer 171 will also change over time.

If there are two devices, these two load converters +7
There is a time delay (T) between the change pattern of the strain deformation integral value of 1171, which is determined by the load lowering speed (=) and the interval υ of the weights 151 in the height direction, and by detecting this, the load can be determined. You can know the rate of decline.

In the figure (to) is a distortion deformation value condition meter.

Ma = L / T ...... ■Furthermore, from the above-mentioned unloading speed (v) and the change pattern of the strain deformation integral value, the respective transit times (tl) of the coke layer and sintered ore layer are calculated. You can know the layer thickness (ω).

dCustomer Ma・t......00 By following the procedures described above, the unloading of the contents in the furnace is completed at a speed of 2.
Therefore, the layer thickness ratio can be determined.

-Also, by pushing the guide pipe 31 into the furnace or pulling it out, = by changing the radial position of the hammer ts+, the unloading speed at any position in the radial direction, j:
3 thickness ratios are obtained, and the radial distribution of these views can be known.

A method for operating a blast furnace using each of the data described above will be explained based on FIG. 5.

■First, data on the unloading speed (ma) and layer no. 1 ratio of the furnace charge (2) obtained through the processes of The sonde (
Input the radial furnace temperature and gas composition distribution positioning according to 9), perform reaction/heat transfer calculations for each zone in the radial direction, and estimate the shape and position of the cohesive zone in the furnace.

Here, the method of estimating the shape and position of the cohesive zone by numerical calculation itself is not significantly different from that used in conventional blast furnace mathematical models, and is not a new technology.

■On the other hand, the management indicators used to determine the necessity of operational actions are:
It is set empirically based on the correlation between the shape and position of the cohesive zone in the furnace obtained by the above-mentioned manuals for each blast furnace and the number of slips of the contents in the furnace. It is. For example, Figure 6 shows a man-made blast furnace (inner volume 3,700m).
', the furnace diameter is 10 m), and there is a relatively good correlation between the cohesive zone height at a position of L5 to 2°0 m from the furnace wall and the number of slips in the furnace.
The height of the cohesive zone up to this point is used as a management index.

However, the method of setting such management indicators naturally differs among the six furnaces.

θ The shape of the in-furnace cohesive zone calculated in (2) above is compared with the management index described in [Phase] to determine whether or not operational action is necessary. Furthermore, the distribution of contents in the furnace is
By adding the Yon model to this, it is also possible to instruct the blast furnace operator on specific actions.

(Example) (1) In a blast furnace (inner volume: 3700 i, furnace diameter: 10 m), the rate of unloading of the contents in the furnace and the layer thickness ratio were measured using the method of the present invention. Its main specifications are shown below [Figure 7].

Heavy cone: φ50■ Ball aviator installation position: Approximately 1 m from the furnace wall and close to the center, and approximately 5 m below the stock line (upper cone position f!1).

Spacing between two heavy cones: 550 dew Length of feeding from the tip of the guide pipe: Approximately 400 fi (
However, in order to prevent the upper and lower guide pipes from interfering with each other, the operating positions of both the upper and lower guide pipes are offset by approximately 50 mm in the circumferential direction.

Figures 8 (a) and (b), 9, and 10 show the output waveforms of the upper and lower load detectors (6), and the data on the unloading speed and layer thickness ratio determined using the waveforms. .

■ By pushing in and pulling out the guide pipe +31131 at the radial measurement position of the load detector +61 +61 shown in (■) above, the unloading speed and layer thickness ratio at positions 1 m and 15 m from the furnace wall can be adjusted to approximately 20 Measurements were taken alternately at minute intervals, and using this data, the previously described operations of Φ to θ were performed to control the shape of the cohesive zone in the furnace.

Figure 11 shows the results of estimating the position of the cohesive zone in the furnace using the measurement data of the unloading velocity determined by the method of the present invention and the layer thickness ratio of the contents in the furnace, and the results of estimating the position of the cohesive zone in the furnace using the conventional vertical sonde. The shape of the cohesive zone estimated using the zone measurement value and the measurement value of the furnace top profile meter is shown. (See the same figure) 15II As is clear, the cohesive zone shape determined using the data obtained by the method of the present invention shows a reasonable shape.

■Figure 12 shows the period when the furnace top profile meter was used to manage the melting in the furnace, the three zones, and the distribution of the contents in the furnace in the blast furnace. This figure shows the change in the number of occurrences of in-furnace slip at time ω) when similar control was performed using the values. During this period, there were no major operational changes other than the control of the input distribution inside the reactor.

As is clear from the figure, the period when the method of the present invention was used)
Compared to period (A) using the conventional method, the number of slips due to large scratches was a little over 1.

(Effects of the Invention) As described above, according to the method of the present invention, it is possible to detect the unloading of the contents in the blast furnace with good accuracy, which greatly contributes to the stable operation of the blast furnace by preventing the occurrence of slips. be able to.

[Brief explanation of the drawing]

1] is a drawing showing an example of an apparatus l for carrying out the method of the present invention, and FIG.
Figure 3 is a Chinese-style diagram of Figure 2, Figure 4 is a diagram of the relationship between the unloading speed and the integrated value of strain deformation due to changes in the charge grains +t in the furnace,
Figure 8g5 is an explanation flowchart of the method of the present invention and the blast furnace operating method based on the data obtained by the method of the present invention, No. 6
The figure shows the relationship rΔ between the position of the cohesive zone above the tuyere and the average number of slips.
, FIG. 7 is an explanatory diagram of the installation position of the load detector in one embodiment of the method of the present invention, (a) is a flat stone diagram, (2)) is a front view 1,
Figure 8 shows the output values of the load detectors in the case of the embodiment shown in Figure 7; The detected value of velocity, Figure 1O shows the detected value of layer 4 ratio, respectively, Ql 11 U;! J
Figure 12 shows the estimated fusion position d' when using the method of the present invention and when using the conventional method, and Figure 12 shows the average number of slips when controlling using the conventional method and the method of the present invention. This is a drawing shown. 111 is the furnace wall, (2) is the furnace contents, (31 is the guide pipe, (4) is the wire, (51 is the heavy cone, and (6) is the load detector. Patent applicant: Sumitomo Metal Industries, Ltd. 12 Seki

Claims (1)

[Claims] (1) Two or more guide pipes are inserted into and out of the blast furnace wall at a required interval in the furnace height direction into the packed bed inside the blast furnace, and these guide pipes are penetrated. A heavy cone attached to the tip of a wire guided into the packed bed in the furnace measures the load received from the furnace contents descending inside the furnace with a load detector attached to the rear end of the wire via the wire. 1. A method for detecting unloading in a blast furnace, characterized by measuring the unloading speed and layer thickness of materials loaded into the furnace.