KR102343595B1 - How to blow the converter - Google Patents

Abstract

The converter blowing method is a converter blowing method in which oxygen gas is injected from the nozzle of the upper blow lance to the molten iron surface in the converter, and the amount of dust in the exhaust gas generated during blowing is obtained, and the dust generation rate in the converter is calculated. And, the relationship R1 between the number of times of use of the top blow lance and the dust generation rate when the lance gap, which is the distance between the molten iron surface and the tip of the top blow lance obtained in advance, is set to an optimal interval, in the speed calculation step In order to correct the shift amount calculated in the shift amount calculation step, from the shift amount calculation step of obtaining the calculated shift amount of the dust generation rate, and the relationship R2 of the change amount of the lance gap and the change amount change amount relationship R2 of the dust generation rate obtained in advance It has a position adjustment process of adjusting the said lance gap during the said blow temper.

Description

How to blow the converter

The present disclosure relates to a converter blowing method using a top blowing lance.

In a converter, blow tempering is performed using a top blow lance (henceforth, it describes as a "lance" suitably). In this blow temper, oxygen gas is injected toward the molten iron|metal surface (molten iron|metal surface) from the nozzle hole provided in the lance, stirring of molten iron|metal, and removal of Si, Mn, P, and C by an oxidation reaction are performed. In the case of blow temper, dust is generated from the converter by the bounce or decarburization reaction on the molten iron surface of the oxygen gas injected from the nozzle hole of the lance. The generated dust is discharged together with the exhaust gas. Since this dust mainly contains iron content (iron, iron oxide), and it leads to loss of iron content when it is discharged|emitted, it is desirable to reduce it.

In blowing using a top blow lance, when oxygen gas collides with a molten iron|metal surface according to an oxygen supply rate and lance height (nozzle front-end|tip position), the shape of the molten iron|metal surface in a converter changes.

At a constant oxygen supply rate, the smaller the lance gap, which is the distance between the molten iron and the tip of the nozzle, the smaller the shape of the molten iron when oxygen gas collides with the molten iron (inverted ohmic cross-section), and the generated dust does not scatter. Since it becomes easy to collect into the inside of molten iron|metal without it, it is known that the amount of generation|occurrence|production of dust can be reduced. This is called hard blow.

On the other hand, when a lance gap is made small too much, since a nozzle receives the thermal influence from a molten iron|metal surface strongly, it is known that wear of a nozzle increases and the life of a lance becomes short. Thus, when the life of a lance becomes short, since the exchange frequency of a lance becomes high, it exerts a bad influence on operation.

From the above facts, there exists an optimal space|interval which reduces the generation amount of dust in a lance gap maintaining the lifetime of a lance, and it is calculated|required that blow temper is carried out by the space|interval. The optimal space|interval of a lance gap (Hereinafter, it describes as an "optimum lance gap" suitably) is set according to the size of a converter, and an oxygen supply rate.

In order to set a lance gap to an optimal space|interval, it is necessary to grasp|ascertain the height of a molten iron|metal surface, As that method, there exists a technique disclosed in Unexamined-Japanese-Patent No. 11-52049, for example. Specifically, molten iron and scrap or can alloy (ferroalloy contained in drum cans, etc.) are charged into the converter, and then microwaves are transmitted toward the furnace from the movable microwave transmission/reception antenna installed in the sublance hole of the upper hood of the converter. And, it is a method of measuring the height of the molten iron surface (the level of the hot water surface) from the received signal.

After the measurement of the height of a molten iron|metal surface is performed until starting blow temper (before start of blow temper) after charging molten iron etc. in a converter. Although there is no clear description of the time required for measuring the molten iron surface height in Japanese Patent Laid-Open No. 11-52049, the molten iron surface fluctuates immediately after charging. There is, it is difficult to measure the height of the molten iron surface every time whenever molten iron is charged in the converter from the viewpoint of affecting productivity.

So, based on the measured value of the molten iron surface height when measured with a microwave molten iron gauge, the estimated value (estimated molten iron surface height) of the molten iron surface height for each blow when not actually measured is calculated using the following formula (1) are doing

(Estimated molten iron surface height) = {(WTn-WT ₀ )/(ρπr ₀ ² )}+l ₀ ... (One)

Here, ρ is the specific gravity of iron, r ₀ is the radius (inner diameter) of the cross section of the converter near the molten iron surface, l ₀ is the measured value of the molten iron surface height by a microwave molten iron gauge, and WT ₀ is the converter measured by a microwave molten iron gauge WTn is the amount of charge in the converter when calculating the estimated height of the molten iron.

However, since the refractory material attached to the inner surface of the converter is repeatedly worn and repaired, the radius of the cross section of the converter is changed for each blow. For this reason, whenever repeating blow temper from the measurement of the molten iron|metal face height by a microwave molten iron gage, a deviation will generate|occur|produce in estimated molten iron face height and actual molten iron face height. For this reason, it became impossible to set a lance gap to an optimal space|interval.

The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a converter blowing method capable of blowing in an appropriate lance gap even when not actually measuring the height of the molten iron.

The present inventors discovered the following knowledge, as a result of earnestly examining the method of setting the optimal lance gap in the method of inserting a top blowing lance in a converter and performing blow temper.

A lance gap can be estimated from a dust generation rate using that the generation|occurrence|production rate of dust changes with the fluctuation|variation of a lance gap.

However, since the flow (oxygen jet) of the oxygen gas injected according to the deformation|transformation of a lance (nozzle shape) changes when the number of times of use of a top blow lance increases, even if a lance gap is constant, a dust generation rate changes. That is, it is difficult to estimate the lance gap only by the dust generation rate.

Therefore, the lance gap is adjusted based on the dust generation rate considering the influence of the number of times the lance is used.

This indication is made|formed based on the above knowledge, The summary is as follows.

The converter blowing method of one aspect of this indication is a converter blowing method which injects oxygen gas to the molten iron|metal surface in a converter from the nozzle of an upper blow lance, The dust amount in the exhaust gas which generate|occur|produces during blow is calculated|required, The dust generation rate in the said converter The relationship between the number of times of use of the top blow lance and the dust generation rate when the speed calculation process for calculating , The amount of deviation calculation step of obtaining the amount of deviation of the dust generation rate calculated in the speed calculation step, and the relationship R2 between the amount of change in the lance gap and the amount of change in the dust generation rate obtained in advance, calculated in the deviation amount calculation step In order to correct the said shift|offset|difference amount, it has the position adjustment process of adjusting the said lance gap during the said blow tempering.

According to the present disclosure, even when not actually measuring the molten iron surface height, it is possible to provide a blower blower method capable of blowing in an appropriate lance gap.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the refinery installation to which the converter blow temper method which concerns on one Embodiment of this indication is applied.
It is explanatory drawing of the dust concentration measuring apparatus of the refinery facility shown in FIG. 1A.
Fig. 2A is a cross-sectional view on the tip side of a top blowing lance used in the refining facility shown in Fig. 1A.
Fig. 2B is a cross-sectional view on the tip side of the upper blowing lance shown in Fig. 2A, showing a state in which the nozzle is worn by use.
It is a graph which shows the relationship between the change amount of the lance gap in each use frequency|count of a top blow lance, and the change amount of the dust generation rate in a converter.
It is a graph which shows the relationship between the frequency|count of use of a top blowing lance, and the dust generation rate in a converter when a lance gap is made into an optimal space|interval.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this indication is described, referring drawings.

The converter blow temper method which concerns on one Embodiment of this indication is the blow temper method used by the refinery|refining installation 9 shown to FIG. 1A and FIG. 1B. First, after demonstrating the refining installation 9 of this embodiment, the converter blowing method of this embodiment is demonstrated.

1A and 1B , the refining facility 9 includes a converter 10 , a top blowing lance 11 (hereinafter, appropriately referred to as a “lance”), and an exhaust gas treatment device 17 . is equipped with

As shown in FIG. 2A, the lance 11 is a member for injecting oxygen gas to the molten iron|metal surface S in the converter 10 from 11 A of nozzles mentioned later. This lance 11 has a cylindrical shape, and is movable upward and downward in the vertical direction by a lifting device (not shown). By moving the lance 11 up and down, the lower part (tip side) of the lance 11 can be inserted or removed from the inside of the converter 10 . In addition, the lance 11 can be stopped at arbitrary height positions with a lifting device. The lance gap G mentioned later can be adjusted by vertical movement of this lance 11. In addition, arrow UP in FIG. 2A has shown the upper direction of a vertical direction. In addition, arrow AXL in FIG. 2A has shown the central axis of the lance 11. As shown in FIG.

Moreover, the front-end|tip part of the lance 11 becomes a nozzle part, and 11 A of some nozzles are provided in this nozzle part. These nozzles 11A are through-holes having a narrowed middle portion, that is, a Laval nozzle, and are provided in a plurality of concentric circles centered on the central axis AXL of the lance 11 at regular intervals. In addition, regarding 11 A of nozzles, you may form also on the central axis AXL of the lance 11.

As shown in FIG. 2A , the oxygen gas A supplied to the lance 11 is sprayed from the nozzle 11A. Here, the jet of oxygen gas A injected from the nozzle 11A toward the molten iron surface S is expanded to an angle making the free expansion angle phi after forming the jet core, and collides with the molten iron in the converter 10 . Thus, a fire point concave in a small shape is formed in the molten iron surface S (in addition, the illustration of the fire point is omitted in FIG. 2A).

As shown in FIG. 1A , the exhaust gas processing apparatus 17 is an apparatus for wet processing _{exhaust gas (gas mainly composed of CO, CO 2} , and N _{2 gas) containing dust generated from the converter 10 .} to be. This exhaust gas processing apparatus 17 is equipped with the furnace mouth hood 18, the exhaust gas duct 12, the primary dust collector 13, the secondary dust collector 19, etc.

The furnace mouth hood 18 and the exhaust gas duct 12 are provided above the converter 10 . Further, on the downstream side of the exhaust gas duct 12, a primary dust collector 13, a secondary dust collector 19, and a manned blower (not shown) are sequentially provided. The exhaust gas of the converter 10 is sucked in by the manned blower, and is dust-removed by the primary dust collector 13 and the secondary dust collector 19 through the furnace mouth hood 18 and the exhaust gas duct 12 . In addition, the dust-removed exhaust gas is passed through a manned blower, and the exhaust gas with a high CO concentration is sent to a gas holder (not shown) as oil gas, while the exhaust gas with a low CO concentration is burned at the top through a chimney (not shown). dissipated into the atmosphere.

The primary dust collector 13 and the secondary dust collector 19 respectively wet-dust the exhaust gas, for example, a venturi scrubber is used.

The water collection water (indicated by an arrow W in FIGS. 1A and 1B) introduced into the primary dust collector 13 collects dust in exhaust gas, and turns into dust collection water containing dust. The collected water is temporarily stored in the lower water tank 14 provided just below the primary dust collector 13, and then is sent to a water collecting treatment device (not shown) to remove the dust in the collected water.

Moreover, as shown in FIG. 1B, the exhaust gas processing apparatus 17 is equipped with the dust concentration measuring apparatus (Hereinafter, it describes as "measuring apparatus" suitably) 20 for measuring the dust concentration. This measuring apparatus 20 is equipped with the pump 15 which collect|collects continuously the collected water which has passed through the primary dust collector 13, and the vibration-type density meter 16 for measuring the density of the collected water. In this measuring device 20, the collected water is continuously collected by the pump 15, and using the vibrating density meter 16, continuous measurement of the dust concentration in the collected water per unit time is performed according to the relationship with the water temperature at that time. It is performed (continuous measurement of the amount of dust in the exhaust gas which generate|occur|produces during blowing of the converter 10 is performed). Here, most of the dust generated in the converter 10 , at least 90% or more, is removed by the primary dust collector 13 . For this reason, if the dust concentration in the dust collected by the primary dust collector 13 is measured, the dust concentration in the exhaust gas of the converter 10 can be estimated.

In addition, the collected water after the dust concentration measurement is returned to the lower water tank 14 .

Next, the converter blow temper method of this embodiment is demonstrated.

The converter blowing method of this embodiment inserts the front-end|tip side of the lance 11 in the converter 10, as shown to FIG. 1A and FIG. 1B, From the nozzle 11A of the lance 11, the converter 10 It is a blow tempering method in which oxygen gas A is sprayed to the inner molten iron surface (S) and decarburized. And when this converter blow temper method performs blow temper, it is characterized by making the lance gap G (refer FIG. 2A) which is the distance of the front-end|tip of the molten iron|metal surface S and the lance 11 into an optimal space|interval, It is characterized by the above-mentioned. In addition, not only the upper odor but the upper and lower odor which used a low odor together may be sufficient as a blow temper.

In detail, the above-mentioned converter blow temper method calculates|requires the amount of dust in the exhaust gas which generate|occur|produces during blow temper, The speed calculation process of calculating the dust generation speed GR;

Amount of deviation to obtain the amount of deviation of the dust generation rate GR calculated in the speed calculation step with respect to the relationship R1 between the number of times of use of the lance 11 and the dust generation rate GR when the lance gap G obtained in advance is the optimum interval calculation process;

In order to correct the shift|offset|difference amount calculated|required in the shift|offset|difference amount calculation process from the relationship R2 of the change amount of the change amount of the lance gap G and dust generation rate GR calculated|required beforehand, the position adjustment process of adjusting the lance gap G during the said blow tempering

a way to have

In addition, said speed calculation process, shift|offset|difference calculation process, and a position adjustment process are processed by the computer (arithmetic means) of the operator who performs converter operation. In addition, the relationship R1 used by the shift|offset|difference amount calculation process, and the relationship R2 used by the position adjustment process are made into a database, for example. Moreover, said computer receives various information for performing converter operation, and also performs control of converter operation (for example, start and stop of blow tempering, adjustment of lance gap G) etc. (that is, a computer controls means being).

In addition, although the above-mentioned computer is a conventionally well-known thing provided with RAM, CPU, ROM, I/O, and a bus|bus connecting these elements, it is not limited to this.

First, each calculation method of the above-mentioned dust generation rate, the relation R1, and the relation R2 is demonstrated.

In the converter operation, as shown in Fig. 1A, the lance 11 is inserted into the furnace from above the converter 10, and the oxygen gas A is injected into the molten iron at high speed, so that impurities such as Si, C, P, and Mn are is removed (decarburized). At that time, fine dust is generated by the splashing of the injected oxygen gas A on the molten iron surface S and the breaking of the CO gas accompanying the decarburization reaction on the molten iron surface S.

The generated dust passes through the furnace mouth hood 18 together with the exhaust gas generated from the converter 10, is sucked into the exhaust gas duct 12, and is contained in the collected water supplied from the primary dust collector 13, while being contained in the lower water tank ( 14) and sent to the water collection treatment device, where it is separated and recovered. In addition, the dust generated from the converter 10 is separated from the exhaust gas by spraying of the collected water from the primary dust collector 13, and the exhaust gas is sent to the downstream side.

(Calculation method of dust generation rate in converter 10)

As shown in Fig. 1B, in the measuring device 20, the collected water is continuously collected by the pump 15, and the vibration-type density meter 16 is used to collect the collected water per unit time according to the relationship with the water temperature at that time. Continuous measurement of the dust concentration in launching is performed. From the product of the dust concentration measured by the above method and the amount of water sprayed per unit time of the collected water (the amount of water sprayed from the primary dust collector 13), the dust generation rate during blowing of the converter 10 can be calculated .

(Method of calculating relationship R2)

The molten iron|metal surface S in the converter 10 (for example, about 400 ton of molten iron|metal amount of a converter) is measured with the microwave molten iron gauge which is not shown in figure, and the lance gap G for every number of times of use of the lance 11, and oxygen If the relationship between the average dust generation rate GR in the decarburization peak period, which is a period in which decarburization occurs preferentially with respect to supply, is approximated, the relationship shown in FIG. 3 is obtained. The number of times of use N of this lance 11 corresponds to the number of times of blow tempering of the converter 10 (it is the same hereafter). In addition, in FIG. 3, when the number of times of use of the lance is about 50 (when the number of uses is small: black circles in FIG. 3), and when about 200 times (when the number of times of use is large: white circles in FIG. 3) display), the same behavior is shown even within the range of 50 to 200 times.

As shown in FIG. 3, dust generation rate GR increases linearly with the raise of the lance gap G (here, the range of 2500-3000 mm), The relationship is a lance accompanying an increase in the number of times of lance use N The inclination is constant regardless of the deformation|transformation of the nozzle 11A of (11). In addition, the "slope" here is the gradient which divided the change amount of the dust generation speed|rate GR by the change amount of the lance gap G (namely, relationship R2).

(Calculation method of relation R1)

The molten iron surface S in the converter 10 is measured with a microwave molten iron gauge, and the dust generation rate GR in the decarburization peak period with respect to the number of lance use N when the lance gap G is set as the optimal interval is shown in FIG. relationship (ie, relationship R1).

As shown in FIG. 4, when the lance gap G is set to the optimal value, the dust generation rate GR is increasing with the increase of the frequency|count N of lance use. In the curve shown in Fig. 4, when the dust generation rate is y and the number of times the lance is used is x, y = 6.9492x ^0.0698 .

The dust generation speed GR of the converter 10 is calculated by the above method, and the speed calculation process, the shift amount calculation process, and the position adjustment process are sequentially performed using the relationship R1 and the relationship R2 calculated|required beforehand.

(Speed calculation process)

First, based on the estimated molten iron surface height obtained by the above formula (1), the lance height is set so as to become the optimal lance gap G, the converter 10 is blown, and using the blow tempering method described above, The average dust generation amount (dust amount) in the exhaust gas generated in the peak period of decarburization is calculated, and the dust generation rate GR of the converter 10 is calculated.

(Deviation amount calculation process)

Dust of the converter 10 calculated in the speed calculation process from the relationship R1 of the number of times of use of the upper blow lance 11 in the previously calculated|required optimal lance gap shown in said FIG. 4, and the dust generation rate of the converter 10 The extent to which the generation rate GR is shifted is determined. Specifically, the difference (namely, shift|offset|difference amount) of the value of the dust generation rate GR calculated|required from FIG. 4 according to the number of times of lance use N, and the value of the dust generation rate calculated by the speed calculation process is calculated|required.

Here, when the calculated value of the dust generation rate GR is lower than the value of the dust generation rate GR according to the number of times of use of the lance N shown in FIG. 4, the actual lance gap G is small with respect to the optimum lance gap G (hard blow ), so it is necessary to greatly adjust the lance gap G. On the other hand, when the calculated value of the dust generation rate GR is higher than the value of the dust generation rate GR corresponding to the number of times of lance use N shown in FIG. 4, the actual lance gap G is large with respect to the optimal lance gap G (soft blow ), so it is necessary to adjust the lance gap G small.

(position adjustment process)

In order to correct the shift|offset|difference amount calculated|required by the shift|offset|difference amount calculation process from the relationship R2 of the change amount of the lance gap G and the change amount of the dust generation rate GR which were previously calculated|required shown in said FIG. 3, the lance gap G is adjusted during blow tempering. In addition, in this embodiment, while calculating|requiring dust generation|occurrence|production rate GR during the decarburization peak period by blow tempering, the lance gap G is adjusted.

As described above, the gradient obtained by dividing the amount of change in the dust generation rate GR by the amount of change in the lance gap G, which shows the relationship R2 between the amount of change in the lance gap G and the amount of change in the dust generation rate GR, is approximately constant regardless of the number of times of use of the lance N do. From this relationship, the adjustment amount of the lance gap G for correcting the shift|offset|difference amount of dust generation speed|rate GR is calculated|required, and the lance gap G is adjusted during blowing of the converter 10.

Specifically, the amount of deviation of the dust generation rate GR obtained in the deviation amount calculation step is divided by the gradient described above to obtain the adjustment amount of the lance gap G corresponding to the amount of deviation of the dust generation rate GR, and the amount of adjustment of the lance ( 11) Adjust the lance gap G by changing the height position.

In addition, although adjustment of said lance gap G (that is, a speed calculation process, a shift|offset|difference amount calculation process, and a position adjustment process) should just be performed once by one blow temper, it can also be performed several times as needed.

Here, as shown in FIG. 2B, as for the lance 11, when the number of uses N increases, the outlet part of the nozzle 11A wears out, and there exists a tendency for an outlet diameter to increase. When the outlet diameter of the nozzle 11A is enlarged, energy loss at the nozzle outlet occurs and the jet core length becomes shorter, so that the force of the oxygen gas A is lowered. However, in the converter blowing method of this embodiment, in order to adjust the lance gap G based on the dust generation rate GR which also considered the influence of the number of times of use N of the lance 11, since the lance gap G is used, the molten iron|metal surface height is not actually measured using a microwave molten iron gauge. Even when it is not, blowing of the converter 10 can be performed with the appropriate lance gap G. Thereby, when the amount of dust becomes excessive by becoming excessively soft blow (the lance gap G becomes large), and by becoming excessively hard blow (the lance gap G becoming small), reducing the life span of the lance 11 remarkably suppression and further preventable.

Example

Next, examples will be described in order to confirm the effects of the present disclosure.

Here, the result of applying each method of an Example and a comparative example is demonstrated when molten iron|metal amount is 400 tons, and optimal lance gap G blows a converter on the conditions which are 3000 mm.

In addition, the Example is the result of performing the speed calculation process of the above-mentioned embodiment of this disclosure, the shift|offset|difference calculation process, and the position adjustment process sequentially, and adjusting the lance gap G according to the dust generation speed GR, The comparative example, It is the result of adjusting a lance gap based on the estimated molten iron|metal height obtained from said Formula (1).

Evaluation is an average lifespan that is the average value of the number of charges until water leaks from the lance in the number of trials (N=10) for 10 times (N=1) of the test for one lance, and It carried out using the measured dust generation amount (dust amount). In addition, the leak from a lance originates in that the lance has a water cooling structure, and is caused by wear and tear accompanying long-term use of the lance. In addition, the dust generation amount was the value obtained by adding the product of the dust concentration in the collected water measured by the dust concentration measuring device and the water sprinkling amount per unit time (1 second) of the collected water through 1 charge, and dividing by 400 tons of molten iron. .

The average lifespan was about 300 charges in the Examples compared to the 250 charges in the comparative example, and the 50 charges were superior.

Dust generation amount was able to reduce 0.3-0.7 kg/ton by the average value of the test charge for one lance in the Example with respect to the average value of 15 kg/ton of all the test charges of a comparative example.

From the above facts, by applying the converter blow temper method of the present disclosure, blow tempering can be performed in an appropriate lance gap, and it has been confirmed that the generation amount of dust can be reduced while maintaining the life of the lance.

As mentioned above, although this indication was demonstrated with reference to embodiment, this indication is not limited at all to the structure described in the above-mentioned embodiment, Other embodiment which can be considered within the range of the matter described in the claim, Modifications are also included. For example, the case where the converter blowing method of this indication is comprised combining a part or all of above-mentioned each embodiment or modified example is also included in the scope of the right of this indication.

In the said embodiment, although the case was demonstrated for the relationship R1 and the relationship R2 respectively using the approximate expression computed from the past operation performance data, it is not limited to this, For example, database formation of the past operation performance data may be used.

In addition, in the said embodiment, the gradient which divided the change amount of the dust generation rate of the converter by the change amount of the lance gap G was used for correction|amendment of the shift|offset|difference amount. Although this gradient was used based on a constant thing irrespective of the number of times of lance use N, for example, a shift|offset|difference amount can also be correct|amended using the gradient obtained for every number of times of lance use.

Moreover, in the said embodiment, the measuring device 20 is equipped with the pump 15 and the vibration-type density meter 16, and collect|collects water collection water continuously with the pump 15, and the vibration-type density meter 16 ) is used to determine the amount of dust by continuously measuring the dust concentration in the collected water per unit time according to the relationship with the water temperature at that time, but the present invention is not limited to this configuration. For example, the measuring device 20 is further equipped with a thermometer, the collected water obtained by wet dusting the exhaust gas is continuously collected, passed through the vibrating density meter 16 and the thermometer, and measured by the vibrating density meter 16 . From the difference between the density of the collected water and the density of pure water predicted from the temperature of the collected water measured with a thermometer, the dust concentration in the collected water may be calculated and the amount of dust may be obtained. Specifically, the dust concentration is calculated using the following formula (2). In addition, the unit of the density|concentration or density in following formula (2) may be kg/m<3> of this embodiment, and g/L or kg/L may be sufficient as it.

C=(ρmeasure-ρwater)×ρdust/(ρdust-ρwater) … (2)

However, C: Dust concentration (kg/m3), ρmeasure: Density of the collected water measured with a vibrating density meter 16 (kg/m3), ρwater: Density of pure water predicted from the temperature of the collected water measured with a thermometer ( kg/m3), ρdust: the density of the dust particles (eg, 7800 kg/m3).

In addition, the vibration type density meter 16 and the thermometer do not care whether either is upstream or downstream.

For example, in the case of using a dust concentration measuring device using ultrasonic waves or light, since the dust concentration is estimated from the attenuation rate, it is affected by the dust particle size. The density of dust, ie, the mass, can be directly measured, so that it is not affected by the dust particle size. Therefore, it becomes possible to measure the dust density|concentration in water collection water accurately with high precision. Thereby, it becomes possible to perform blowing of the converter 10 with the more suitable lance gap G.

Regarding the above embodiments, the following appendices are also disclosed.

(Annex 1)

In the method of performing blow tempering by charging a top blow lance in a converter,

A speed calculation step of measuring the amount of dust in the exhaust gas generated during blowing of the converter to calculate a dust generation rate;

The speed calculation process for the relationship R1 between the number of times of use of the top blowing lance and the dust generation rate of the converter when the lance gap, which is the distance between the tang surface in the converter and the tip of the top blowing lance, which is obtained in advance, is set to an optimal interval A shift amount calculation step of obtaining a shift amount of the dust generation rate of the converter calculated in

From the relationship R2 between the amount of change in the lance gap obtained in advance and the amount of change in the dust generation rate of the converter, in order to correct the amount of deviation obtained in the deviation calculation step, adjusting the lance gap during blowing of the converter It has a position adjustment process, The converter blow temper method characterized by the above-mentioned.

(Annex 2)

In the converter blow tempering method according to Appendix 1, a gradient obtained by dividing the change amount of the dust generation rate of the converter by the change amount of the lance gap is used for correction of the shift amount, The converter blow tempering method characterized in that it is used.

In the above converter blow tempering method, in the shift amount calculation step, when the lance gap is set as the optimal interval, the amount of shift in the dust generation rate calculated in the speed calculation step is obtained for the relationship R1 between the number of times of use of the top blow lance and the dust generation rate, , a position adjustment process WHEREIN: Since a lance gap is adjusted so that the shift|offset|difference amount calculated|required in the shift|offset|difference amount calculation process may be corrected from the relationship R2 of each change amount of a lance gap and a dust generation speed|rate, blowing can be performed with an appropriate lance gap.

Thereby, it suppresses and prevents that the life of a top blow lance is remarkably reduced by becoming excessively soft blow (a lance gap becomes large), and excessively hard blow (a lance gap becomes) by this becoming excessively soft blow (lance gap becomes large). can do.

All publications, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual publication, patent application, and technical standard were specifically and individually indicated to be incorporated by reference. .

10: converter
11: Sangche Lance
11A: Nozzle
16: Vibration-type density meter (density meter)
G: Lance Gap
GR: Dust generation rate
N: Number of uses of the lance

Claims (3)

It is a converter blowing method in which oxygen gas is injected from the nozzle of the upper blow lance to the molten iron surface in the converter,
A speed calculation step of calculating the dust generation speed in the converter by obtaining the amount of dust in the exhaust gas generated during blow tempering;
Calculated in the speed calculation step with respect to the relationship R1 between the number of times of use of the top blow lance and the dust generation rate when the lance gap, which is the distance between the molten iron surface and the tip of the top blow lance obtained in advance, is set to the optimal interval a shift amount calculation step of obtaining a shift amount of the dust generation rate;
Position adjustment process of adjusting the said lance gap during the said blow in order to correct the said shift|offset|difference amount calculated|required in the said shift|offset|difference amount calculation process from the relationship R2 of the change amount of the said lance gap change and the said dust generation rate calculated|required beforehand
A converter blowing method having The method of claim 1,
The converter blow tempering method which uses the gradient which divided the change amount of the said dust generation rate by the change amount of the said lance gap for correction|amendment of the said shift|offset|difference amount. 3. The method of claim 1 or 2,
In the speed calculation step, the collected water obtained by wet dusting the exhaust gas is continuously collected, passed through a density meter and a thermometer, and the density of the collected water measured with the density meter and the temperature of the collected water measured with the thermometer are obtained. The converter blowing method which calculates the dust concentration in water collection water from the difference of the density of the predicted pure water, and calculates|requires the said dust amount.

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