JPH10170166A - Method and system for managing lance of refining furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for managing the lance of a refining furnace in which the lance can be managed without interrupting supply of ore to the furnace using means insusceptible to the atmosphere in the furnace and thereby the operational efficiency is enhanced. SOLUTION: A lance 1 comprising inner and outer tubes 2, 3 are is disposed in a furnace and a material is fed from the inner tube 2 while supplying lance air into the outer tube 3. In such a method for managing the lance of a scouring furnace, pressure in a duct 10 is measured while keeping the current velocity of lance air in the duct 10 at a constant level and then the length of the lance or the dimension of welding loss is determined based on the measurements thus managing the lance 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a smelting furnace,
The present invention relates to a lance management method and a lance management device for a smelting furnace that manages a lance for supplying ore and oxygen to the smelting furnace.

[0002]

2. Description of the Related Art In a smelting furnace such as a smelting furnace or a copper smelting furnace in a copper smelting process, a raw material such as an ore is blown into a molten metal in the furnace together with oxygen for promoting blowing. Lances are provided.

In such a smelting furnace, in order to stabilize the mixing of the ore or oxygen with the molten metal in the furnace, the distance from the lower end of the lance to the molten metal surface is always kept constant. Is needed.

[0004] However, under the high temperature in the furnace,
A phenomenon in which the lance melts from its lower end and decreases (melting)
Therefore, in order to keep the distance from the lower end of the lance to the surface of the molten metal constant, it is essential to inspect the furnace frequently and adjust and manage the height of the lance.

[0005] Therefore, by knowing the length of the lance in the furnace by some means, the distance from the lower end of the lance to the molten metal surface is grasped, and the position of the lance is adjusted based on this result. Has conventionally been adopted. In the lance management method as described above, the work related to the lance length confirmation and the position adjustment is generally performed visually by stopping supply of ore and the like into the furnace.

[0006]

However, when the lance is controlled while the supply of ore is stopped as described above, there is a problem that the operating rate of the furnace is reduced and the efficiency of the operation is hindered. Was. Also, in order to prevent this, even if the lance is checked for the length of the lance by projecting a laser, ultrasonic wave, infrared ray, or the like onto the lance, these lasers or the like may cause dust or the like filling the furnace. It was reflected by gas and the like, and it was difficult to make an accurate measurement that can be put to practical use.

In view of such circumstances, in the present invention, by controlling the lance by means not affected by the atmosphere in the furnace, it is not necessary to stop the supply of ore to the furnace, and as a result, It is an object of the present invention to provide a lance management method and a lance management device for a smelting furnace that lead to an improvement in operation efficiency.

[0008]

In order to solve the above problems, the present invention employs the following means. That is, in the lance management method for a smelting furnace according to the first aspect, a lance composed of an inner tube and an outer tube is provided in the furnace, and the lance is connected to a line connected to the upper end of the outer tube of the lance. A lance management method for a smelting furnace that supplies a raw material from the inner pipe while supplying lance air into the pipe, wherein the flow rate of the lance air in the pipe is kept constant, The method is characterized in that a pressure is measured, and a length or a erosion dimension of the lance is obtained based on the measurement result to manage the lance.

In this method of managing a lance of a smelting furnace,
Since the pressure in the pipeline is measured while keeping the flow rate of the lance air constant, the change in pressure loss due to the change in the length of the lance appears as a change in pressure. For example, the amount of erosion of the lance can be detected, so that the lance can be managed.

A lance management method for a smelting furnace according to claim 2 is the lance management method for a smelting furnace according to claim 1,
The lance is a top-blown lance.

[0011] In the lance management method of the smelting furnace,
Since the lance has a lower pressure of the lance air as compared with a case where the lower end is an immersion lance whose lower end is immersed in the molten metal, it is possible to detect a change in pressure due to erosion of the lance as an effective value. .

A lance management method for a smelting furnace according to claim 3 is the lance management method for a smelting furnace according to claim 1 or 2, wherein the vertical position of the lance is adjusted based on the measurement result. The lower end position of the lance is adjusted to a fixed position.

In the lance management method for a smelting furnace,
The length or erosion dimension of the lance is known based on the measurement result of the pressure in the pipeline, and based on the result, the adjustment amount of the vertical position of the lance is determined, and the lower end position of the lance is adjusted to an appropriate position. Is done.

A lance management device for a smelting furnace according to claim 4 is provided with a lance comprising an inner tube and an outer tube in the furnace.
In a lance management device for a smelting furnace that supplies a raw material from the inner tube, while supplying lance air into the outer tube from a pipe line connected to an upper end side of the outer tube of the lance, the pressure of the lance air is reduced. It is characterized by comprising a measuring means for measuring, a lance position moving mechanism for adjusting the vertical position of the lance, and a control unit for controlling the lance position moving mechanism based on a measurement result of the measuring means.

[0015] In the lance management device of this smelting furnace,
If the flow rate of the lance air is kept constant, a decrease in pressure loss in the lance due to melting of the lance will appear as a change in the pressure of the lance air. Knowing the erosion dimensions,
Based on the result, the lance position moving mechanism can be driven by the control unit to manage the position of the lance.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a state inside a smelting furnace, and reference numeral 1 represents a lance. Lance 1
Is composed of an inner tube 2 and an outer tube 3. The inner tube 2 supplies ore and air to the furnace, and the outer tube 3 supplies oxygen and air to the furnace. Below the lance 1, a melt 5
Is retained, and the lance 1 is moved from its lower end 1 a to the molten metal 5.
Is placed in the furnace such that the distance to the molten metal surface 6 becomes l ₁ . A lance header 9 is provided above the furnace ceiling 7 and the furnace top floor 8 above the lance 1 (outside the furnace), and air is supplied to the lance 1 from outside the furnace. A conduit 10 for feeding is connected.

A lance 1 is connected to the pipe 10 through the pipe 10.
Is provided with a pressure measuring point 11 for measuring the pressure of air (lance air) supplied to the
It is connected to measuring means 12 for specifically detecting the value of the pressure in the pipeline 10. The measuring unit 12 is connected to a control unit 13, and the control unit 13 is connected to a lance position moving mechanism 14 that enables the lance 1 to move up and down. The measuring unit 12, the control unit 13, and the lance position moving mechanism 14 are configured as a lance management device 15 that can control the lance position moving mechanism 14 based on the measurement result of the measuring unit 12 and manage the lance. ing.

The above is the main configuration of the present embodiment. Next, a lance management method using the lance management device 15 will be described. This lance management method is lance 1
The length of the lance 1 or the length of the lance 1 by utilizing the fact that when the lower end of the lance 1 is melted and its length is shortened, the energy loss due to pipe friction in the lance air flowing through the lance 1 is also reduced. Is detected, and the distance l ₁ between the lance 1 and the molten metal surface 6 is adjusted to an appropriate value based on the detection result.

FIGS. 2A, 2B and 2C show the lance 1 length L and the lance air pressure P, respectively.
FIG. To grasp the relationship between the length L and the pressure P, see No. 1, No. 2, No. 3 for the three types of lances, which correspond to (a), (b), and (c), respectively. As can be seen from FIG. 2, the lance length L and the lance air pressure P have a relationship substantially as represented by a straight line in the figure. Therefore, it can be said that it is appropriate to know the erosion size of the lance 1 by monitoring the amount of change in the lance air pressure P.

The specific procedure of the lance management method according to this embodiment will be described below. First, keep the lance air flow rate and furnace air pressure constant,
The lance header pressure Ph which is the pressure of the lance air before the lance air flows into the lance 1 (in this case,
The pressure at the pressure measurement point 11 is measured and monitored by the measuring means 12. In this way, the change amount ΔP of the pressure Ph due to the melting of the lance 1 is detected.

Next, the erosion dimension La of the lance 1 is determined from the pressure change amount ΔP. The pressure change amount ΔP is related to the erosion dimension La of the lance 1 by the following equation relating to the pipe friction loss.

(Equation 1) Where: λ: coefficient of friction of the pipe of the lance 1 γ: air density (kg / m ² ) La: erosion dimension of the lance 1 (m) D: inner diameter of the lance 1 (m) V: flow velocity of the lance air (m / s) g: Gravitational acceleration (m / s ² ).

As described above, the pressure change amount ΔP and the lance 1
The control unit 13 obtains the erosion dimension La of the lance 1 using the relational expression with the erosion dimension La of the lance 1. If the length of the lance 1 when the lance 1 is first installed in the furnace is known, the length L of the lance 1 after the erosion is obtained from the subsequent erosion dimension La. It will be.

Finally, the length L of the lance 1 after erosion
Alternatively, based on the erosion dimension La, the control unit 13 determines the moving dimension of the position of the lance 1 so that the lower end 1a of the lance 1 is located at an appropriate position, and based on the result, the lance position moving mechanism 14 Adjust the lower end position of the lance 1.

The above is the lance management method using the lance management device 15 in the present embodiment. Next, a test for examining the validity of the lance management method of the present embodiment and the results thereof will be described. In this test, the lance header pressure Ph is calculated from the lance length L using the above equation, and the calculated result is compared with the actual lance header pressure Ph.

In order to calculate the lance header pressure Ph using the above equation, it is necessary to first obtain the friction coefficient λ1 of the single pipe portion and the friction coefficient λ2 of the double pipe portion in the lance 1. The calculation of these friction coefficients was performed as follows. When determining the friction coefficient λ2 of the double pipe portion, as shown in FIG.
The position of the inner tube 2 is fixed, and the position of the lance header 9 is moved downward by the distance of the erosion dimension (the length l ₂ of the single tube portion does not change, and the length l _{3 of the} double tube portion does not change). Lance header pressure), and the lance header pressure is measured in this state and compared with the pressure before lance 1 melting. The friction coefficient λ2 of the double pipe portion is obtained from the pressure decrease values obtained before and after the lance 1 erosion and the erosion dimension of the lance 1. Table 1 shows the results.

[Table 1]

When the friction coefficient λ1 of the single tube portion is obtained, as shown in FIG. 3B, if the lance 1 is damaged, the position of the inner tube 2 and the position of the lance header 9 are not changed. Next, the lance header pressure is measured. At this time,
Lance 1 of the length of single pipe portions before and after melting l ₄ decreased by l ₅ becomes also, since the length l ₃ of the double pipe portion does not change, the pressure reduction value before and after the melting of the lance 1 When,
From the erosion size of the lance 1, the friction coefficient λ1 of the single pipe portion is obtained. Table 2 shows the results.

[Table 2]

The friction coefficients λ1, λ obtained as described above
2, the lance header pressure Ph is determined from the above equation, but in this case, the handling of the inner diameter D of the lance 1 in the double pipe portion becomes a problem. In this test, the calculation of the lance header pressure Ph was performed by replacing the inner diameter D of the lance 1 in the above equation with the following hydraulic diameter D 'in the portion of the lance 1 having the double pipe structure. went.

(Equation 2) Here, D ′: hydraulic diameter (m) R2: inner diameter of outer tube 3 (inner diameter of lance 1) (m) R1: outer diameter of inner tube 2 (m)

The friction coefficients λ1, λ obtained as described above
FIG. 4 is a graph showing the calculation of the lance header pressure Ph and the lance header pressure Ph based on 2, the inner diameter D of the lance 1, and the like, and comparing the results with actual measured values. Note that the results shown in the figure are based on the lance header 9 corresponding to the erosion dimensions of the single pipe part.
And the distance l from the lance lower end 1a to the molten metal surface 6
_{This is a case where 1} is always kept constant and the length l ₃ of the double tube portion is gradually reduced. According to the graph shown in FIG. 4, the measured value and the calculated value of the lance header pressure Ph indicate which lance (No. 1, No. 2,
No. In 3), they are almost the same. From the above results, conversely, the lance header pressure Ph to the lance length L
It is considered that it is sufficiently possible to predict.

As described above, in the lance management device 15 and the lance management method of the smelting furnace according to the present embodiment, it is possible to predict the length of the lance or the erosion dimension of the lance from the pressure of the lance air. Therefore, it is not necessary to stop the supply of the ore or the like to the furnace and to visually confirm the position as in the related art when managing the adjustment and replacement of the lance. Therefore, by employing the lance management device 15 of the present embodiment and the lance management method of the smelting furnace, the operating rate of the furnace can be improved,
Thereby, the operation efficiency can be improved.

In the lance management method for a smelting furnace according to the present embodiment, since the erosion size and the like are known from the lance air pressure change, the pressure change due to the lance air melting can be detected as a significant value. As described above, it is desirable that the pressure of the lance air is small, and therefore, it is preferable that the lance air is used for management of an upper blowing lance like the lance 1 in FIG.

Further, in the lance management method for a smelting furnace according to the present embodiment, based on the measurement result of the lance air pressure,
Since the position of the lance is to be adjusted, it is not necessary to stop the supply of ore and the like to the furnace and to visually confirm the position when adjusting the position of the lance as in the conventional case. The adjustment work can be performed by automatic control, and therefore, the efficiency of the operation can be improved.

In the above embodiment, when the lance length L is known, the lance length L is determined in advance, and then the lance length L is determined from the length before the lance melts. However, the lance length L may be directly calculated from the lance air flow rate, the air pressure in the furnace, the lance header pressure, and the like.

[0033]

As described above, according to the lance control method for a smelting furnace according to the first aspect, the pressure in the pipeline is measured while the flow rate of the lance air in the pipeline is kept constant. In order to manage the lance by knowing the length or erosion dimension of the lance based on the measurement results, the supply of ore etc. to the furnace was stopped as in the past when managing the adjustment and replacement of the lance, etc. Then, it is not necessary to visually confirm the position, and therefore, the operation rate of the furnace can be improved, and the operation efficiency can be improved.

According to the lance control method of the smelting furnace according to the second aspect, since the lance is a top-blown lance, the amount of change in the lance air pressure due to melting of the lance can be easily detected. The invention according to 1 can be easily realized.

According to the lance control method of the smelting furnace according to the third aspect, the lance position is adjusted based on the measurement result of the lance air pressure. It is not only necessary to stop the supply of ore and the like to the furnace and visually check the position, but also it is possible to perform these position adjustment operations by automatic control, thereby improving the efficiency of operation. Can be.

According to the lance control apparatus of the smelting furnace according to claim 4, the pressure of the lance air is measured by the measuring means,
Based on the result, the control unit drives the lance position moving mechanism to adjust the lance position.When adjusting the lance position as in the related art, the supply of ore and the like to the furnace is stopped, and the lance position is visually checked. Not only does the position need not be confirmed, but it is also possible to perform these position adjustment operations by automatic control, thereby improving the operation rate and operating efficiency of the smelting furnace.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing the inside of a smelting furnace and a lance provided in the smelting furnace according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between measured values of a lance air pressure and a lance length to show the validity of the principle of the lance management method for a smelting furnace of the present invention.

FIG. 3 is a view showing a procedure for estimating a friction coefficient of a double pipe portion and a single pipe portion in a lance in order to perform a test showing the validity of the lance management method of the smelting furnace of the present invention. .

FIG. 4 is a graph showing a relationship between a lance header pressure and a lance length for showing a result of a test showing adequacy of a lance management method for a smelting furnace of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lance 2 Inner pipe 3 Outer pipe 10 Pipe line 11 Pressure measuring point 12 Measuring means 13 Control part 14 Lance position moving mechanism 15 Lance management device

Claims (4)

[Claims] 1. A lance comprising an inner tube and an outer tube is provided in a furnace, and a lance air is supplied into the outer tube from a line connected to an upper end of the outer tube of the lance while the lance air is supplied to the inner tube. A lance management method for a smelting furnace that supplies a raw material from a pipe, wherein the flow rate of the lance air in the pipe is kept constant, and the pressure in the pipe is measured. A lance management method for a smelting furnace, wherein the lance is managed by knowing the length or erosion dimension of the lance. 2. The lance management method for a smelting furnace according to claim 1, wherein said lance is a top-blown lance. 3. The lance management method for a smelting furnace according to claim 1, wherein a vertical position of the lance is adjusted based on the measurement result.
A lance management method for a smelting furnace, comprising adjusting a lower end position of the lance to a fixed position. 4. A lance comprising an inner tube and an outer tube is provided in a furnace, and lance air is supplied into the outer tube from a line connected to an upper end side of the outer tube of the lance. In a lance management device for a smelting furnace that supplies a raw material from a pipe, a measuring unit that measures a pressure of the lance air, a lance position moving mechanism that adjusts a vertical position of the lance, and based on a measurement result of the measuring unit. A lance management device for a smelting furnace, comprising a control unit for controlling the lance position moving mechanism.