JPS63171819A - Control apparatus for optimum blowing quantity of molten iron treating agent - Google Patents

Abstract

PURPOSE:To surely enable the coincidence of composition value with the aimed value after treating by an automatic and simple apparatus, by using the quantity corresponding to the integral value as treating molten iron quantity, which is the basis for calculating the blowing quantity of treating agent, and the actual value as composition value in the molten iron before treatment. CONSTITUTION:In a pretreatment by blasting method on a molten iron trough in the blast furnace, the composition in the molten iron before treatment is measured by a rapid analyzer 8. And, the molten iron weight in mixer car corresponding to time integral value for molten iron tapping velocity is measured by a load-cell 7. The blowing quantity for the treating agent per unit time is calculated by a first arithmetic unit 9a from analyzed composition value before treatment and the actual measured receiving quantity for the molten metal per unit time. From this blowing quantity and the optimum weight ratio of the treating agent to carrier gas, pressure in dispenser tank 20, flushing gas quantity and booster gas quantity are calculated by a second arithmetic unit 9b. Based on these calculated values, the control panel 9c controls the pressure in a tank 20 and each gas flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a hot metal pretreatment process in which hot metal tapped from a blast furnace is desiliconized, desulfurized, and dephosphorized in a hot metal trough. More specifically, the present invention relates to an apparatus for controlling the amount of processing agent blown and the solid/air ratio to optimum values in pretreatment by a blasting method.

(Prior art) In preliminary treatment by the blasting method, the treatment agent in the dispenser tank is carried on a flancing gas (N, gas) and discharged, and this is energized by a booster gas and transferred to the hot metal trough using a blasting lance. In order to make the components of the pre-treated hot metal blown into the dispenser tank match the target value, the amount of treatment agent blown at this time must be controlled according to the target value and the pre-treatment component value. In order to prevent blockage of the processing agent transport pipe from the to the lance and to prevent sbrushes during blowing, it is necessary to control the solid/gas ratio of the processing agent and carrier gas to an optimal value.

In order to make the components of the hot metal after treatment match the target values, it is necessary to accurately determine the treatment agent injection rate. For this purpose, it is necessary to accurately know the tapping rate, the components of hot metal before treatment, etc.

However, in the conventional hot metal pretreatment blast furnace hot metal gutter desiliconization (sulfur, phosphorus)
The injection speed and amount of treatment agent in the method are determined based on the component analysis values of the previous tap tap and the component estimation from blast furnace thermal control model calculations, as it takes time to analyze the tapped iron components of the hot metal before treatment. It is determined from the value and tapping speed.

For example, in the conventional blasting method, the amount of processing agent, etc. is controlled as follows. The operator estimates the treatment agent component value of the hot metal from the components of the previous tap tap.

Furthermore, the operator calculates the tapping speed from the tapped iron weight measured by a load cell that measures the weight of the pig iron mixing truck. From these values, the operator determines the treatment agent Wl (velocity) required to bring the treated hot metal components back down to the target value. Furthermore, the operator determines the pressure inside the dispenser tank necessary to transport and blow the processing agent amount into the hot metal at the optimum surface/air ratio.
Determine the amount of flancing gas and booster gas, and set the instruction and adjustment control panel to adjust these pressures and flow rates.

However, in the conventional blasting method control, the component values before treatment are estimated values, and the tapping speed varies, so the component values after treatment vary widely from the target values. There is.

Furthermore, it is troublesome for the operator to visually check changes in the tapping speed and change the settings each time.

By the way, as a method for hot metal pretreatment, there is an overlay method in addition to the blasting method. Processing agent injection speed control in the overlay method also has the same problem as mentioned above, but
Publication No. 49413 proposes the following control device as a means to solve this problem.

That is, the processing part component values and tapping speed of hot metal are actually measured, and the processing agent injection speed W is determined as W - (1/k) based on these measured values.
- Calculate and add by (initial value - target value) x (tapping speed). (Here, k is a constant that corresponds to the weight of hot metal treated by a unit weight of treatment agent. Also, the initial value is the hot metal component value before treatment.) Furthermore, by actually measuring the hot metal component value after treatment. The actual value of the constant is calculated and the value of k is constantly updated.

However, the device proposed in this publication has a complicated configuration, and the measurement of hot metal components and velocity must be carried out continuously or at minute time intervals of about several seconds. Therefore, it is not possible to deal with troubles such as failure of the detection end.

Furthermore, the apparatus disclosed in this publication is based on the overlay method and cannot be used with the blasting method for the following reason. That is, in the blasting method, in order to prevent the occurrence of clogging of the transport pipe, it is necessary to control the ratio of the processing agent and the carrier gas to a certain value or less. Furthermore, in order to prevent hot metal splash at the blasting lance where the treatment agent is blown, it is necessary to control the amount of carrier gas within a predetermined limit relative to the amount of treatment agent.

Furthermore, the internal volume of the dispenser tank is, for example, 20×3
, and the response is slow even if continuous control is performed like the device in the publication (for example, 3 to 5 seconds with an internal volume of 2 (ls)).
This requires a response time of in. ) (Problems to be Solved by the Invention) Therefore, the purpose of the present invention is to control the amount of treatment agent blown, which solves the problems of the above-mentioned prior art, and which can also be used for preliminary treatment of hot metal such as desiliconization by blasting method. B. To provide a device. In particular, it does not require any operation by an operator (,
It is an object of the present invention to provide a control device for controlling the optimum injection amount of a processing agent, which has a simple device configuration and can reliably bring a post-processing component value close to a target value.

(Means for Solving the Problems) The gist of the present invention is to provide a control device for preliminary treatment such as desiliconization using a blasting method on a hot metal gutter of hot metal tapped from a blast furnace. An analyzer for analysis, a weight measuring device for measuring the weight of hot metal tapped from a blast furnace, passed through a hot metal gutter, and stored in a pig iron mixing car, and a component analysis value of hot metal obtained by the analyzer and a hot metal after treatment. a first calculating means for calculating the amount of treatment agent blown per unit time from the component target value and the hot metal weight measured by the weight measuring device; From the optimal weight ratio of the processing agent and carrier gas, calculate the pressure inside the dispenser tank that stores the processing agent, the amount of flushing gas to the tank, and the amount of booster gas that assists in transporting the processing agent discharged from the tank. a second calculation means; and a control means for controlling the pressure inside the tank and the flow rate of each gas based on the pressure inside the dispenser tank, the amount of flushing gas, and the amount of booster gas calculated by the second calculation means. This is a control device for the optimum amount of hot metal pretreatment agent.

(Function) a) Determination of injection amount The treatment agent injection 1w per unit time is calculated by the following formula % formula by the first calculation means based on the processing section analysis component value and the sudden measurement value of hot metal received per unit time in the mixing car. % × (Sudden value of hot metal received per unit time in the mixed pig iron car) where A (kg/lp+j is the hot metal unit calculated from the ratio of target component value and processing section analysis component value (target value / processing section analysis value) Processing agent injection amount per weight (tuts) (kg
).More specifically, A is given by A = -(1/K)·In (target value/processing unit analysis value), where K is the correction value. Further, the amount of hot metal accepted into the pig iron mixing car per unit time corresponds to the hot metal extraction rate after treatment.

b) Calculation of tank internal pressure and carrier gas amount In the blasting method, the amount of processing agent input is not only controlled to the optimum value, but also the weight ratio of processing agent and total amount of carrier gas (
It is necessary to control the solid/gas ratio within a predetermined range to prevent clogging of transport pipes and splashing during blowing.

The discharge rate of the processing agent from the dispenser tank is a above
), and is controlled by the tank internal pressure and the flushing gas flow rate for carrying out the processing agent from the tank. Therefore, the second arithmetic unit first determines the tank internal pressure and flushing gas flow rate necessary to discharge the processing agent blowing 'WkW determined in the above-mentioned item a) from the dispenser tank.

Next, the calculation device calculates the amount of booster gas that makes the solid/gas ratio a predetermined optimum value from the optimal solid/air ratio, the processing agent injection amount W determined above, and the amount of flushing gas.

(Example) Next, an example in which the present invention is applied to desiliconization preliminary treatment of hot metal will be described in detail with reference to the accompanying drawings.

The hot metal 4 tapped from the blast furnace 1 and discharged as slag by the skinmer 2a is transferred to the hot metal mixer car 6 via the hot metal gutter 2 and the tilting gutter 5.
contained within.

On the other hand, a desiliconizing agent for preliminary treatment is stored in a dispenser tank 20 from a hopper 11 having a bag filter 10. The desiliconizing agent in the tank 20 flows through the flow orifice 23
The gas is carried by the flancing gas (NZ gas) blown through the flow rate control valve 21 and discharged from the tank 20.

The desiliconizing agent discharged from the tank 20 is sent to the transport pipe 15 via the flexible hose 13 and the automatic on-off valve 14. At this time, a booster gas (CNt gas) is added via the flow rate orifice 18, the flow control valve 17, and the flexible hose 16 to optimize the ratio (solid/air ratio) of the desiliconizing agent and carrier gas in the transport pipe 15. Adjust to value.

The desiliconizing agent transported through the transport pipe 15 is blown into the hot metal from the blasting lance 3, and performs preliminary desiliconization treatment on the hot metal 4.

A control device according to the present invention for controlling the amount of blown desiliconizing agent is configured as follows.

The pre-treatment hot metal sample taken by the load cell operator or robot is subjected to component analysis by a rapid analyzer 8 having a built-in microprocessor, and the silicon component value of the treated portion is measured.

Further, the weight of hot metal in the pig iron mixing car corresponding to the time integral value of the tapping speed V is measured by a rotor self.

The first calculation unit W9a of the construction equipment calculates the amount of desiliconizing agent injected per unit time using the following formula from the pre-treatment analytical component values measured by the analyzer 8 and the rotor self and the actually measured amount of hot metal accepted per unit time. .

W = (1/treatment agent efficiency)
...+1) Here, A (kg/lpt*) is the target silicon component value 5
LCf) and the pre-processing analytical component value St (3) ratio C3z
Hot metal unit type f calculated from (f)/St (i)
f1(tp+j) is the treatment agent injection it (kg) per unit.More specifically, with K as the correction value, A= (1/K) ・In (St(4)/5t(i
)) ... f21 (where In is a natural logarithm) That is, S+(f) = S+(i) ・exp(- to -A) is given.

Figure 2 shows S when K = 0.04, (f)/S
t (i) and A (kg/s+in/l, =, /+wi
This shows the relationship n=kg/1ptj. 1st
The calculation device determines A using the relationship shown in FIG. 2 and the above equation (2), and further uses the above equation +11 to determine the blow
Calculate W.

Star I Calculation Cap 1 The second calculation unit N9b calculates the internal pressure of the dispenser tank 20, the amount of flushing gas, and the amount of booster gas based on the blowing rate 1w calculated by the first calculation unit 9a.

■Determination of tank internal pressure and flushing gas amount The pressure in the dispenser tank 20 and the flushing gas amount are calculated using the dispenser tank characteristics shown in FIG. 3 based on the injection iWA calculated by the first calculation device 9a. Ru. Desiliconization material discharged per unit time Il(k
g/m1n) must be equal to the blowing rate 1w per unit time determined by the first calculation unit T19a. The tank pressure P and flushing gas amount 0° required for this are determined using the characteristics shown in FIG. (
In FIG. 3, P0 to P7 are dispenser tank pressures (kg/cd), and as the pressure increases from Po to P, discharge! W also increases. -0〈...＜-
7 indicates the solid/gas ratio at the time of discharge from the dispenser tank.) To explain this more specifically, by giving W, a straight line parallel to the horizontal axis in FIG. 3 is determined. If an appropriate tank internal pressure P is selected here, one point on the straight line is determined and the gas NQ is determined.

is decided.

■ Calculation of Booster Gas Amount In the blasting method, the solid/gas ratio during transportation must be optimally selected (JMo) to prevent blockage of the transportation pipe and splash during blowing.

The tank internal pressure P and flushing gas amount determined in (■) above are 0. The solid/gas ratio of the desiliconizing agent discharged from the tank 20 is generally smaller than this optimum value Mo.
That is, the flushing gas amount Qt and the booster gas l! kQ
Optimize the ratio (solid/air ratio) of the sum of h Qt + IIh) to 4
The amount of booster gas Q required to equalize 11Mo,
is calculated using the following formula.

MO=W/(Qv+QJ'...(3+(M here)
o is the weight ratio (kg/kg), that is, Qb '' (W/Mo) Qt... (41 Note that the first and second arithmetic units 9a and 9b perform the operations of ■ and ■ above. Specifically, it can be constructed from a single sequencer board or microprocessor.

Country! The control panel 9c is a normal control instrument panel, and the second computing unit W
Tank pressure P and gas amount Ω1 calculated by 9b,
Based on Ob, the pressure in the dispenser tank 20, the amount of flushing gas, and the amount of booster gas are controlled.

■Pressure control Pressure detector 25 detects the pressure within tank 20.

The control panel 9c controls the pressure in the tank 20 to the calculated value P by adjusting the pressure regulating valve 22 and the pressure relief valve 12.

■Gas amount control Control panel 9 by adjusting each flow rate adjustment valve 21.17
c controls the flow rates of the flushing gas and booster gas to a calculated value Qt, respectively.

(Effect of the invention) In the present invention, the hot metal weight corresponding to the integral value is used instead of the hot metal velocity as the treated hot metal amount which is the basis for calculating the treatment agent injection amount, and the pre-treatment hot metal component values are based on actual analysis. Use analytical values. Therefore, a device as simple as a sequencer can make the processed component values match the target values. In particular, compared to the devices proposed in the above-mentioned publications, the present invention provides a simple and inexpensive device that can be applied to the blasting method, with a) real-time component detection, intermittent component detection rather than controlled 2N; , Good control.

b) Analysis of hot metal components after treatment is unnecessary.

C) The tapping speed of the hot metal treatment section is unnecessary, and the hot metal tapping speed after treatment is sufficient.

d) Although there is a gutter cover over the hot metal gutter, a detection device inside the gutter cover is unnecessary and practical.

There is an effect.

Furthermore, with a simple configuration, it is possible to automatically control the blowing amount and solid/gas ratio in the blasting method to optimal values without operator intervention.

The following table shows actual measurement results comparing the component analysis values before and after the desiliconization pretreatment of hot metal is controlled using the control device of the present invention. (The silicon component value before treatment is 0
．． Target silicon content value is 0.27% for hot metal of 30% or more.
It was subjected to desiliconization treatment. Note that the tapping in Run 1 and Run 2 is the state immediately after operation. ) The average of the hot metal silicon component analysis values after treatment for all 975 cars of Run 1 to 5, which were the subject of this actual measurement, was 0.279 as calculated from the table.
%, and the average variation range of the analyzed values was approximately 0.01%, indicating that control was performed with extremely high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention; FIG. 2 is a graph that is the basis for calculating the processed injection amount in the apparatus shown in FIG. 1; and FIG. 3 is a graph showing processing agent discharge characteristics of a dispenser tank of FIG. 1: Blast furnace 2: Hot metal trough 3: Desiliconizing agent blasting lance 4: Hot metal 5: Hot metal tilting shaft 6: Mixing pig iron car 7: Load cell for measuring hot metal weight 8: Rapid analyzer 9a: First computing device 9b = Second
Arithmetic device 9c: Control panel 10: Bag filter-11
: Desiliconizer receiver hopper 12: Dispenser pressure relief valve 13: Flexible hose 14: Automatic opening/closing valve 15: Transport pipe 16: Flexible hose

Claims (1)

[Scope of Claim] A control device for preliminary treatment such as desiliconization using a blasting method on a hot metal gutter of hot metal tapped from a blast furnace, comprising: an analyzer for analyzing the components of hot metal before treatment; a weight measuring device that measures the weight of the hot metal that has passed through and is stored in the mixing car; a component analysis value of the hot metal obtained by the analyzer and a target component value of the hot metal after treatment; a first calculating means for calculating the amount of treatment agent blown per unit time from the weight of the hot metal; a second calculation means for calculating the pressure in the dispenser tank housing the dispenser tank, the amount of flushing gas to the tank, and the amount of booster gas for assisting the transportation of the processing agent discharged from the tank; A control device for controlling the optimum amount of hot metal pretreatment agent, comprising: control means for controlling the pressure inside the dispenser tank and the flow rate of each gas based on the values of the pressure inside the dispenser tank, the amount of flushing gas, and the amount of booster gas.