JP4157090B2 - Hot metal supply method to converter - Google Patents

Description

  The present invention relates to a hot metal supply method to a converter.

As is well known, the hot metal produced in the blast furnace is loaded into a kneading car (torpit car) and then transferred to a converter process for adjusting the components of the hot metal. Further, in the kneading vehicle, the auxiliary raw material is introduced into the hot metal charged therein, and dephosphorization, desiliconization, and desulfurization are performed to preliminarily perform hot metal component adjustment processing (hot metal preliminary processing). Process).
In the converter process, molten iron is charged into the converter, dephosphorization and decarburization are performed by adding auxiliary materials and blowing oxygen to produce molten steel with a predetermined phosphorus concentration and carbon concentration. Like to do. The molten steel obtained in the converter process is then formed into a slab or the like through a continuous casting process, and steel products such as thick plates and thin plates are manufactured by rolling the slab (rolling step).

In order to increase the production volume of steel products, it is important to pay attention to the blast furnace process and increase the amount of hot metal discharged from the blast furnace, but the production capacity in other processes, for example, the hot metal pretreatment process, is important. It is also important to raise. Techniques for improving the production capacity of each process are disclosed in Patent Documents 1 to 3, for example.
Patent Document 1 focuses on the blast furnace process and considers the operating status (distribution status) of the hot metal transport container between the blast furnace and the steelmaking factory to verify the balance of the storage amount between the blast furnace and the steelmaking factory. Techniques for preventing steel failure are disclosed.

Patent Document 2 pays attention to the hot metal preliminary process, and has a plurality of process patterns for processing an object to be processed in lot units, and in the hot metal preliminary process line that executes the processes according to the plurality of process patterns in parallel, the payout process A physical distribution simulation method capable of setting an in-process amount at a proper value is disclosed.
Patent Document 3 discloses a logistics planning technique that focuses on the rolling process and focuses on the flow (distribution) of the rolled material until the heating furnace is charged, and considers the improvement of the production amount in the slab rolling process.
On the other hand, regarding the converter process, it is the processing capacity of the converter itself and the hot metal supply capacity to the converter that are related to the molten steel production capacity. If a plurality of converters are operated simultaneously, the processing capacity of the converter exceeds the hot metal supply capacity to the converter, and the hot metal supply capacity to the converter becomes rate-limiting. In other words, how efficiently and quickly the hot metal supply to the converter is performed is very important.

Patent Document 4 discloses a distribution technology for efficiently handling a ladle in a part of the converter process in order to improve the hot metal supply capacity to the converter. The converter equipment disclosed in this document has one crane, two ladles, one transport cart for conveying the ladle, and a ladle set device between the two converters. The ladle set device is arranged so as to straddle the traveling rail, and has a function of lowering the ladle after receiving an empty ladle from a crane and mounting the ladle on a transport cart.
As a result, two ladles can be used alternately for one transport cart, and even if one ladle is being charged into the decarburization converter, the other ladle can be used. The pan can be quickly moved to the outlet of the dephosphorization converter.
JP 2003-82407 A (pages 4 to 8) JP 2002-62924 A (pages 3 to 5) JP-A-10-272505 (pages 3 to 7) Japanese Patent No. 3503938 (pages 4 to 5, FIG. 5)

Usually, a converter facility has a plurality of converters, a plurality of ladle for charging molten iron into these converters, and a “dispensing station” (place for discharging) that discharges hot metal from the kneading car to the ladle. As shown in Fig. 3 (a), the ladle loaded with molten iron is transported between multiple converters and stations by a crane, and only pays attention to the movement of the ladle. However, it is a complicated logistics form.
The inventor of the present application examined in detail the operating conditions of the ladle and the crane on the basis of the Gantt chart of FIG. 3 (a) and the like in order to find a method for improving the molten steel production capacity in the converter process. As a result, there is a play time / waiting time of the crane such as “when the hot metal is discharged to the ladle 103, the crane 104A is in a waiting state over the discharge station 106A”, and the ladle in operation It has been found that there is a problem that the number of the ladle is as small as two and it is not possible to hold another ladle during the waiting time.

In other words, it was clarified that the use of a ladle according to the operational status of the crane would improve the operational status of the crane and increase the hot metal supply capacity to the converter.
However, the technique of Patent Document 4 described above pays attention only to a part of the converter process, and it is difficult to solve the above problems and greatly improve the hot metal supply capacity to the converter. In order to efficiently supply hot metal to the converter, it is important to move the ladle efficiently throughout the converter process. To that end, the operating status of the crane should be as good as possible. is required.

On the other hand, it is very difficult to apply the physical distribution technology of Patent Documents 1 to 3 to the converter equipment.
Then, this invention provides the hot metal supply method to the converter which can perform hot metal supply to a converter efficiently by using the ladle according to the operation condition of a crane in view of the said problem. The purpose is to do.

In order to achieve the above object, the present invention takes the following technical means.
In other words, technical means for solving the problems in the present invention include a converter, a ladle for charging molten iron into the converter, a dispensing station for discharging molten iron to the ladle, and a removal for the dispensing station. This is a converter facility having a crane for handling the ladle in a predetermined cycle in order to carry in or out the pan, and the time interval at which the crane charges the hot metal into the converter is defined as a hot metal charging pitch Pt. In accordance with the input pitch Pt, the number of ladle operations is set, the ladle for the set operation number is handled with a crane, and when supplying hot metal to the converter, The hot metal charging pitch Pt and the net crane cycle time Cn are determined so as to satisfy the following equation.

ROUND_UP (Cn / R / Pt) ≤ Number of ladle operations ≤ ROUND_UP (Tn / R / Pt)
... (1)
Pt ≧ Cn / R (2)
Cn: Crane net cycle time
= Time that the crane is actually operating within one cycle of the crane (min / cycle)
Tn: Net cycle time
= Total time for each process such as hot metal discharge, desulfurization, etc.
+ Crane net cycle time Cn (min / cycle)
R: Number of crane bases (base)
Pt: Hot metal charging pitch (min / charge)
ROUND_UP (X): X is rounded up. The crane at the converter facility places an empty ladle on the discharge station → transports the completed ladle to the converter → returns the empty ladle to the discharge station again A predetermined operation such as transfer is performed periodically, that is, in a predetermined cycle. Accordingly, the hot metal supply to the converter is also performed in a predetermined cycle, and the time interval is a hot metal charging pitch Pt (substantially the same as the molten steel output steel pitch, which is the time interval at which the molten steel is extracted from the converter). is there.

Although the hot metal charging pitch Pt is shortened, the hot metal is frequently charged into the converter, but in order to cope with the shortened hot metal charging pitch Pt, the number of ladle operations is increased. There is a need. On the other hand, when the hot metal supply pitch becomes long, if the current number of ladle operations is used, the number of ladles in a waiting state increases, so the number of ladles needs to be reduced.
As can be seen from this, since the number of ladle operations is closely related to the hot metal charging pitch Pt, the technical means sets the number of ladle operations based on the hot metal charging pitch Pt. I am doing so. Thereby, the operating number of the ladle which carries hot metal to a converter can be made appropriate, and it becomes possible to supply hot metal efficiently to a converter.

On the other hand, as shown in Fig. 7 (a), the molten steel production volume of the converter depends on the market demand trend and the repair and inspection troubles of related facilities in the steelworks. There is no need to keep it constant, and it is necessary to change it flexibly. Conversely, if the operation is continued with the converter equipment operating at a fixed value, the amount of steel output from the converter becomes excessive, heat loss occurs throughout the converter process, and the ladle Or refractories in the converter will be deteriorated more than necessary.
In order to change the operating status of the converter equipment, as described above, the operating number of the ladle may be changed according to the increase / decrease in the hot metal charging pitch Pt. In addition, the time during which the crane is actually operating within one cycle of the crane is the crane net cycle time Cn, and this Cn may be shortened or lengthened to adjust the hot metal supply capacity to the converter. Even when the crane net cycle time Cn increases or decreases, it is necessary to change the operating number of ladles to cope with it.

In view of these things, the operating number of the ladle is determined so as to satisfy the equations (1) and (2) including the hot metal charging pitch Pt and the crane net cycle time Cn.

ROUND_UP (Cn / R / Pt) ≤ Number of ladle operations ≤ ROUND_UP (Tn / R / Pt)
... (1)
Pt ≧ Cn / R (2)

Cn: Crane net cycle time
= Time that the crane is actually operating within one cycle of the crane (min / cycle)
Tn: Net cycle time
= Total time for each process such as hot metal discharge, desulfurization, etc.
+ Crane net cycle time Cn (min / cycle)
R: Number of crane bases (base)
Pt: Hot metal charging pitch (min / charge)
ROUND_UP (X): Rounds up X

For example, if the crane net cycle time Cn is 30 minutes, the hot metal charging to the next converter is completed, the next hot metal charging is completed (the hot metal is discharged from the kneading car with one ladle, the converter It will take 30 minutes to load. On the other hand, if the hot metal charging pitch Pt is 15 minutes, this interval will not be in time. If two ladles are set, theoretically, hot metal supply will be in time. That is, the operating number of ladles can be obtained by dividing the crane net cycle time Cn by the hot metal charging pitch Pt (Cn / Pt).

Here, even if the crane net cycle time Cn is 30 minutes, if the number of cranes R is two, the crane net cycle time can be virtually considered to be 15 minutes. In addition, since the number of ladle needs to be an integer, it is good to use the rounded-up value (round up) of the calculated value as the operating number of ladle.
From these facts, it can be seen that the lower limit value of the number of ladle operations can be obtained from ROUND_UP (Cn / R / Pt) ≦ the number of ladle operations (left side of equation (1)).

On the other hand, the upper limit value of the number of ladle operations is determined based on the same concept, but instead of using the crane net cycle time Cn, the crane net cycle time Cn is used for the time taken for each process such as hot metal discharge and desulfurization. It is determined using the “net cycle time Tn” with the sum added. The net cycle time Tn can also be considered as a time during which some action is taken on the hot metal.
For example, if the net cycle time Tn is 45 minutes, it takes 45 minutes for the ladle to be discharged from the kneading car with one ladle and to be charged into the converter after performing molten iron treatment such as desulfurization. become. On the other hand, if the hot metal charging pitch Pt is 15 minutes, this interval will not be in time. Therefore, if the number of ladles is set to three, the hot metal supply will theoretically be in time. That is, the operating number of ladles can be obtained by dividing the net cycle time Tn by the hot metal charging pitch Pt (Tn / Pt).

Here, even if the net cycle time Tn is 45 minutes, if the number of cranes R is two, the net cycle time Tn may be considered to be 22.5 minutes virtually. In addition, since the number of ladle needs to be an integer, it is good to use the rounded-up value (round up) of the calculated value as the operating number of ladle.
From these facts, it can be seen that the upper limit value of the number of ladle operations may be obtained from the number of ladle operations ≦ ROUND_UP (Tn / R / Pt) (the right side of equation (1)). Since it does not take more than net cycle time Tn as time until hot metal is charged into a converter, the number of ladle operation calculated based on Tn becomes an upper limit.

Since equation (1) includes Pt as an independent variable, the number of operating ladles described above varies in accordance with the increase / decrease in the hot metal charging pitch Pt.
Note that when the hot metal charging pitch Pt is shorter than the virtually considered crane net cycle time Cn / R, ROUND_UP (Cn / R / Pt) becomes a large value (for example, 5 or 6). It becomes necessary to use a large number of ladles. Since such a situation leads to an increase in the processing waiting time of the ladle, it is unrealistic. Therefore, as shown in the equation (2), the hot metal charging pitch Pt is assumed to be a virtually considered crane net cycle time Cn / R. Equal to or greater than. As a result, the number of ladle operations does not become extremely large.

By using as many ladles that satisfy the equations (1) and (2) described above, the hot metal can be efficiently supplied to the converter.
More preferably, the converter facility has a standby station for repairing the ladle and collecting metal, and operates the ladle of the number of ladle operations + 1 set by any of the technical means. In addition, the crane may be operated to place any one of the ladle at the standby station.
In order to improve the hot metal supply capacity to the converter, it is preferable to increase the number of ladles that supply hot metal. However, when the number of ladle operations increases, the cycle time per ladle is extended, and metal and slag are deposited on the slag line of the ladle. Therefore, in order to perform the converter operation smoothly in response to this, it is preferable to further increase one operating ladle and provide a standby station for placing the increased ladle. With regard to the ladle placed at the standby station, by removing the bullion and slag regularly, it is possible to ensure a stable ladle that does not adhere to the bullion and slag. become able to.

In addition, it is highly preferable to heat the ladle at the standby station.
The ladle at the standby station is an empty hot metal ladle that has not received hot metal inside. If the hot pot continues for a long period of time, the temperature of the refractory inside the ladle will drop. ”Stable operation becomes difficult due to metal adhesion”, “Heat loss increases, the temperature of the hot metal charged into the converter decreases”, “The hot metal charged with refractory expands and exfoliates. Inconveniences such as “doing” occur. Therefore, it is preferable to heat the inside of the ladle by inserting a burner or the like into the ladle in the standby station to generate a flame.

  ADVANTAGE OF THE INVENTION According to this invention, hot metal supply to a converter can be efficiently performed with a converter equipment.

Hereinafter, an embodiment of a hot metal supply method to a converter according to the present invention will be described with reference to the drawings.
FIG. 1 shows an outline when the converter equipment 1 is viewed from the front, and FIG. 2 shows a schematic plan view of the converter equipment 1.
As shown in FIG. 1, the converter facility 1 of the present embodiment conveys the three converters 2, a ladle 3 (hot metal ladle) that supplies hot metal to these converters 2, and the ladle 3. And two cranes 4. Furthermore, after placing the ladle 3, two “dispensing stations 6 (dispensing pits)”, which are places where the hot metal is transferred from the kneading wheel 5 or the blast furnace pan to the ladle 3, are provided.

The present invention sets the operation number of the ladle 3 according to the hot metal charging interval (hot metal charging pitch Pt) to the converter 2 in such a converter facility 1, and the set operation A number of ladles 3 are handled by a crane 4 to supply hot metal to the converter 2.
Hereinafter, the details of the converter facility 1 according to the present embodiment will be described.
A traveling rail 7 is provided on the upper side of the converter facility 1 so as to run through the converter facility 1, and two cranes 4 described later travel on the traveling rail 7. . The payout stations 6A and 6B are provided on one side of the traveling rail 7 (left side in FIG. 2) so as to be aligned in the direction of the traveling rail 7, and 3 on the other side of the traveling rail 7 (right side in FIG. 2). The basic converters (converter 2A to converter 2C) are arranged in the direction of the traveling rail 7. Note that the vertical direction in the following description is the same as the vertical direction in FIG.

As shown in FIG. 2, for the convenience of explanation, the traveling rail 7 is divided into seven sections. Dispensing stations 6A and 6B are provided so as to correspond to the lower side of the traveling rail 7 corresponding to the partition numbers 1 and 2, and below the traveling rail 7 corresponding to the partition numbers 4, 5, and 6. In addition, converters 2A, 2B, and 2C are provided on the side of the traveling rail 7. The crane 4A moves from the partition numbers 0 to 6, and the crane 4B moves from the partition numbers 1 to 7. One delimiter number corresponds to the width of one crane.
In addition, at the position of the partition number 0 and above the payout station 6A, the “scraping station 9A” is a place where the slag floating on the upper surface of the hot metal in the ladle 3 is scraped out by the sword 8A (slag dragger). Is provided. Similarly, a throat oyster 8B is arranged at the position of the delimiter number 3 to form a removal station 9B.

That is, two payout stations 6 that are adjacent to each other in the moving direction of the crane 4 are provided, and the removal stations 9 are provided on both sides in the moving direction of the payout stations 6, respectively. Two cranes 4A and 4B can exist simultaneously.
On the traveling rail 7, two cranes 4A and 4B are provided. Specifically, the crane body 10 travels on the traveling rail 7, and a suspended rope 11 (wire) extends downward from the crane body 10, and the tip of the suspended rope 11 The ladle 3 is suspended by a hook 12 provided on the top. The ladle 3 is lifted upward by winding the suspended rope 11 around the crane body 10, and the ladle 3 is paid out when the crane body 10 travels on the traveling rail 7. It is freely transferred between the station 6 and the converter 2.

The number of ladles 3 used in the converter 1 is determined so as to satisfy the expressions (1) and (2).

ROUND_UP (Cn / R / Pt) ≤ Number of ladle operations ≤ ROUND_UP (Tn / R / Pt)
... (1)
Pt ≧ Cn / R (2)

Cn: Crane net cycle time
= Time that the crane is actually operating within one cycle of the crane (min / cycle)
Tn: Net cycle time
= Total time for each process such as hot metal discharge, desulfurization, etc.
+ Crane net cycle time Cn (min / cycle)
R: Number of crane bases (base)
Pt: Hot metal charging pitch (min / charge)
ROUND_UP (X): Rounds up X

FIG. 8 is a result of calculating the formulas (1) and (2) under the conditions of the present embodiment, and shows the optimum number of ladle 3 operating according to the hot metal charging pitch Pt. is there. The horizontal axis of FIG. 8 is the hot metal charging pitch Pt, and the vertical axis is the number of operating ladles 3.

The calculation conditions are a crane net cycle time of 22 minutes / cycle and a net cycle time of 31 minutes / cycle, a crane base number of 2 and a payout pit number of 2.
The right side of Equation (1) is indicated by a broken line, and the left side of Equation (1) is indicated by a solid line. The area | region shown with this solid line and the broken line has shown the operating number of the ladle 3. For example, when the hot metal charging pitch Pt is 13 minutes, two or three ladles may be operated, and when Pt = 20 minutes, the number of ladle operations may be two.
The range shown by Formula (2) is the area | region on the right side from the vertical line L in a figure, From this, the operating number of the ladle 3 actually applicable to the converter equipment 1 is 3 or less. I understand.

FIG. 7B shows the result of changing the operating number of the ladle 3 based on the above concept. During normal high production, the hot metal dispensing pitch is 15.2 minutes and the number of ladle operations is three. However, when the continuous casting machine in the lower process is inspected and at low production, the hot metal charging pitch is Since it is 19.0 minutes, the number of ladle operations is reduced to two based on the result of FIG. In the prior art 1 and the prior art 2, the number of operations is exactly the same as that in high production, and it seems that heat loss or the like occurs.
Since the hot metal charging pitch is 38.0 minutes in the low production state associated with the blast furnace off-air, the number of ladle operations is reduced to one based on the result of FIG. In the prior art 1 and the prior art 2, the number of operations (= 3) is exactly the same as in high production.

Case K in FIG. 10 is an operation result when the number of ladle operations 3 is three, and the number of ladles 3 is 45 minutes / time for a conventional crane (such as Case F) cycle time. Is appropriate, the crane cycle is shortened to 29 minutes / time.
The outline of ladle movement in the converter 1 is as follows.
First, after the kneading wheel 5 arrives at the converter 1, hot metal is poured from the kneading wheel 5 into the ladle 3 placed on the payout stations 6 </ b> A and 6 </ b> B. The ladle 3 charged with hot metal is lifted up by the cranes 4A and 4B, moved to the removal stations 9A and 9B above the discharge stations 6A and 6B and adjacent to the discharge stations 6A and 6B. 8B, the slag floating on the upper surface of the hot metal is scraped off.

The ladle 3 from which the slag has been scraped is transferred to one of the three converters 2A, 2B, 2C by the cranes 4A, 4B, tilting the converter 2, and tilting the ladle 3 The hot metal is charged into the converter 2.
In the converter 2 charged with hot metal, a lance is inserted from the furnace port of the converter 2 and brought close to the upper surface of the hot metal, and oxygen gas is blown at the same time. To start. At the same time, the slag forming and iron oxide Fe _x O _y or the like coolant such as lime CaO, i.e. the auxiliary raw material input. Phosphorus in the hot metal reacts with the charged oxygen and shifts to the slag phase, and starts laminating above the hot metal (dephosphorization). Furthermore, the carbon in the hot metal reacts with oxygen and CO. It is discharged as gas (decarburization). By this blowing process, molten steel having a predetermined phosphorus and carbon concentration can be obtained.

When the blowing process in the converter 2 starts, the empty ladle 3 is returned again to the discharge stations 6A and 6B by the cranes 4A and 4B, and the molten iron is again ready to be discharged.
In FIG. 3, the number of ladles 3 always disposed in the payout stations 6 </ b> A and 6 </ b> B is one, and the total number of ladles 3 is three (satisfies equation (1) and equation (2)). The Gantt chart showing in detail the movement of the cranes 4A and 4B and the movement (distribution) of the ladle 3 associated therewith is shown.
FIG. 3A is a Gantt chart in the conventional converter facility 101 shown in FIG. In the conventional converter apparatus 101, the removal stations 109A and 109B are provided above the discharge stations 106A and 106B, and the discharge stations 106A and 106B and the removal stations 109A and 109B are the same in plan view. The point existing at the partition number position is greatly different from the present converter facility 1. In addition, in the conventional example, the operating number of ladles 103 is two.

Regarding the movement of the cranes 104A and 104B, first, the crane 104A grips the empty ladle 103 and installs it on the dispensing station 106A (pit A). Thereafter, hot metal is discharged from the kneading wheel 105 to the ladle 103, and component measurement and temperature measurement are performed. Then, the ladle 103 is suspended by the crane 104A, lifted upward, and transferred to the removal station 109A.
At this time, the ladle 103 that has been suspended by the crane 104B is arranged at the dehulling station 109B, and the slag in the ladle 103 is scraped out by the throat oyster 108B. Thereafter, the ladle 103 of the crane 104B is transferred to the position of the converter 102A, and the hot metal is charged into the converter 102A. After the hot metal charging is completed, the ladle 103 that has been emptied is transported and installed in the payout station 106B, and the hot metal discharge starts. At this time, the crane 104B is in a waiting state over the dispensing station 106B.

Under the situation where the hot metal discharge at the discharge station 106B has progressed to some extent, the removal of the ladle 103 suspended from the crane 104A is completed. The hot metal is charged into the converter 102B from the ladle 103. At this time, in order to smoothly move the crane 104A, the crane 104B is moved to the front of the converter 102C at the same time.
The ladle 103 that has been charged into the converter 102B is moved again to the position of the discharge station 106A by the crane 104A and installed, and one cycle of the crane 104A is completed.

At this time, the crane 104B that has been withdrawn before the converter 102C (separation number 6) moves to the upper side of the dispensing station 106B, and lifts the ladle 103 for which the component measurement and the temperature measurement are completed again. This completes one cycle of the crane 104B.
In the present embodiment, the ladle 103, the crane 104, and the payout station 106 always correspond to each other, and it is always the fixed crane 104 that holds a certain ladle 103, and the ladle 103 is always the same payout station. 106. It can be seen from FIG. 3A that the time required for one cycle of the crane 104, that is, the cycle time, is 33 minutes.

Considering the number of ladles that are always placed in the dispensing station 6, as can be seen from FIG. 3 (a), the number of ladles that are always placed is zero or one. There is an undeployed situation.
On the other hand, FIG. 3B shows the movement of the crane 4 of the present embodiment and the movement (distribution) of the ladle 3 associated therewith.
Regarding the movement of the crane 4, the crane 4 </ b> A first installs the empty ladle 3 on the dispensing station 6 </ b> B. Thereafter, the ladle moves to the dispensing station 6A, and the ladle 3 in which the hot metal component measurement and the temperature measurement are completed is lifted up and transferred to the demolition station 9A. In this removal station 9A, the ladle 3 is in a suspended state, and the slag in the ladle 3 is scraped out by the throat oyster 8A.

At that time, the crane 4B is suspending another ladle 3, and the ladle 3 is disposed in the dehulling station 9B, and the slag is removed by the blade 8B. When such removal is completed, the crane 4B moves to the front of the converter 2A, and the hot metal is charged from the ladle 3 into the converter 2A. The ladle 3 that has been emptied after the hot metal charging is completed is transported and installed in the discharge station 6A while being suspended by the crane 4B, and the discharge of the hot metal starts.
The situation where the ladle 3 is installed on the payout station 6A is indicated by the P part in the Gantt chart, which means that the R ′ part in FIG. Looking at the situation of part P from another point of view, the removal station 9A and the payout station 6A are separated by one crane in plan view, so that the crane 4 can be located at both stations simultaneously. This means that the removal of the hot metal and the discharge of the hot metal are performed in parallel, and the hot metal supply process is efficiently advanced. Case C in FIG. 10 corresponds to this situation. Since the crane time of the conventional (case A) is 33 minutes / time, the removal station 9A and the dispensing station 6A are separated from each other. The crane cycle is shortened to 29 minutes / time.

Thereafter, the crane 4B does not wait for the hot metal discharge of the ladle 3 in the payout station 6A to be completed, but hangs the ladle 3 in the adjacent payout station 6B filled with hot metal. Meanwhile, the crane 4A waits at the position of the demolition station 9A in order to wait for this lifting.
The crane 4B that lifts the ladle 3 of the payout station 6B is best if it moves to the removal station 9B as it is, but it is necessary to move the ladle 3 in the removal station 9A before the converter 2A. Therefore, it once moves to the front of the converter 2C (escapes).

  The crane 4A moves to the front of the converter 2B so as to follow the crane 4B, and the hot metal is charged into the converter 2B. The ladle 3 which has been emptied and is emptied is always installed in the dispensing station 6 (in this case, the dispensing station 6B) in which one ladle is empty, and the next hot metal is charged (Fig. 3 (b) Q part). Immediately thereafter, the crane 4 </ b> A hangs the ladle 3 after the completion of the hot metal charging disposed in the dispensing station 6 </ b> A without waiting for the hot metal charging to the ladle 3 to end. This completes one cycle of the crane 4B. In the case of the present embodiment, it can be seen that the time (cycle time) required for one cycle of the crane 4 is 29 minutes from FIG. The crane 4B that had escaped before the converter 2B (separation number 5) moved to the removal station 9B adjacent to the crane 4A when the crane 4A moved to the discharge station 6B. To do.

Considering the number of ladles that are always placed in the dispensing station 6, as can be seen from FIG. 3 (b), the number of ladles that are always placed is 1 or 2 regardless of the portion of the converter process. The number of payout stations-1 = 2-1 = 1 or more.
In addition, in this embodiment, in order to further reduce the cycle time of the crane 4, the converter facility 1 is provided with a standby station 13 for repairing the ladle 3 and collecting metal.
In addition, a crane is prepared so that one ladle 3 is prepared separately from the number of ladles 3 in operation, and both of them are operated together, and any one of the ladles 3 is arranged at the standby station 13. 4 is operated. In the ladle 3 arranged in the standby station 13, metal and slag adhering to the ladle 3 are periodically removed.

  That is, in order to improve the hot metal supply capability to the converter 2, it is preferable to increase the number of ladles 3 that supply hot metal. However, by increasing the number of operating ladle 3, the circulation time per ladle is extended, and metal and slag are deposited on the slag line of ladle 3. Therefore, in order to perform the converter operation smoothly in response to this, it is preferable to further increase the number of ladles 3 in operation and provide a standby station 13 on which the increased ladle 3 is placed. With regard to the ladle 3 placed at the standby station 13, the bullion and slag are periodically removed, so that the ladles 3 that can be used stably without any bullion or slag are reliably secured. Will be able to.

  However, the ladle 3 in the standby station 13 is an empty ladle that has not received hot metal inside. If the state of the empty pan continues for a long time, the temperature of the refractory inside the ladle 3 decreases, When the hot metal is subjected to hot metal, metal adhesion will occur and stable operation will become difficult. ”“ Heat loss will increase and the temperature of the hot metal charged into the converter 2 will decrease. ”“ Refractory material will be charged. Inconveniences such as “thermal expansion and peeling due to hot metal” occur. Therefore, in the case of the present embodiment, by inserting a burner or the like into the ladle 3 in the standby station 13 to generate a flame, the ladle 3 is heated after taking the bullion and the above problem occurs. To prevent. Case D in FIG. 10 corresponds to this situation, and in this case, the number of ladles 3 is set to the number of payout pits + 1, and another ladle 3 is used, for a total of four ladles 3. Is used.

4 and 5 show a second embodiment of the converter facility.
The converter equipment 1 has a desulfurization station 14A and a desulfurization station 14B, and the desulfurization station 14A and the desulfurization station 14B are respectively arranged on the side of the traveling rail 7 at the positions 1 and 2 of the traveling rail 7. Has been. In addition, the front blades are arranged at the position of the partition number 0 to form the removal station 9, and two converters 2A and 2B are provided. Other configurations are substantially the same as those in the first embodiment.
FIG. 9 shows the optimum number of ladle 3 in accordance with the hot metal charging pitch Pt based on the formulas (1) and (2) under the conditions of this embodiment. The horizontal axis of FIG. 9 is the hot metal charging pitch Pt, and the vertical axis is the number of operating ladles 3.

The calculation conditions are that the crane net cycle time is 30 minutes / cycle, the net cycle time is 66 minutes / cycle, the number of crane bases is 2, the number of payout pits is 2, and the number of removal stations is also 2.
The right side of Equation (1) is indicated by a broken line, and the left side of Equation (1) is indicated by a solid line. The area | region shown with this solid line and the broken line has shown the operating number of the ladle 3. For example, when the hot metal charging pitch Pt is 40 minutes, one or two ladles may be operated. When Pt = 20 minutes, the number of ladles operated is any of 2 to 4. Good.

The range represented by the formula (2) is a region on the right side of the vertical line L in the figure, and can actually be applied to the converter facility 1 when the number of operating ladles 3 is 5 or less.
Case L in FIG. 10 is an operation result when the number of ladles 3 is four, and the number of ladles 3 is 45 minutes / cycle for a conventional crane case (such as Case F). Is appropriate, the crane cycle is shortened to 33 minutes / time.
The ladle 3 is moved in the converter facility 1 after the kneading vehicle 5 arrives at the converter facility 1 and then from the kneading vehicle 5 to the ladle 3 placed on the dispensing stations 6A and 6B. Is poured. The ladle 3 charged with hot metal is transferred to the desulfurization stations 14A and 14B, and by adding auxiliary materials such as CaO to the hot metal at the desulfurization station 14, the sulfur S in the hot metal is transferred to the slag layer. The sulfur component (S) in the hot metal is predetermined. In each of the desulfurization stations 14A and 14B, throat oysters 8A and 8B for scraping out the slag generated by the desulfurization process are installed, and the generated slag is scraped out.

The ladle 3 in which the hot metal after the desulfurization treatment is charged is transferred by the cranes 4A and 4B to any one of the converters 2A and 2B, and the converter 2 is tilted and the ladle 3 is tilted. Then, the hot metal is discharged into the converter 2.
In the present embodiment, the ladle 3 is handled by the cranes 4A and 4B so that the number of ladles 3 always disposed in the desulfurization stations 14A and 14B is equal to or greater than “total number of desulfurization stations −1”. Yes. In other words, the idea for using the crane 4 most efficiently applied to the dispensing station 6 is applied to the desulfurization station 14.

  Specifically, one ladle 3 is always arranged at one of the two desulfurization stations 14A or 14B (the number of desulfurization stations is −1 = 2-1 = 1). It is assumed that it is being done. At the same time, the other desulfurization station 14B or 14A is always empty. Therefore, since the cranes 4A and 4B can immediately hold the ladle 3 adjacent to the ladle 14B or 14A after installing the ladle 3 in either the desulfurization station 14A or 14B, the logistics of the ladle 3 It is performed very efficiently, and the hot metal supply to the converter 2 can be performed efficiently.

FIG. 6 shows a Gantt chart showing in detail the desulfurization process of the converter facility 1 described above. The operating number of the ladle 3 in this Gantt chart is three (Equation (1) and Equation (2) are satisfied).
In this Gantt chart, for example, paying attention to part P, the crane 4A moves to the dispensing station 6A immediately after placing the ladle 3 charged with hot metal in the desulfurization station 14B, without waiting, and dispenses. The ladle 3 that is finished is hung.
Further, paying attention to the portion Q, the crane 4B hangs the ladle 3 where the roasting 8 of the desulfurization station 14B has ended immediately after installing the empty ladle 3 in the dispensing station 6B. Paying attention to the R portion, the crane 4B lifts the ladle 3 after the completion of the desulfurization treatment in the desulfurization station 14A immediately after the empty ladle 3 is installed in the payout station 6B.

  On the other hand, paying attention to the S part and the T part of the Gantt chart, the number of operating ladles 3 is also set to “number of payout stations + 1 = 2 + 1 = 3”, so the first ladle 3 is placed in the desulfurization station 14A. When the molten iron is disposed and the hot metal is being processed from the second ladle 3 to the converter 2, it is removed from the third ladle 3 by the front blade 8F.滓 Processing is performed. Thus, since the three ladles 3 are operating in parallel, the hot metal can be supplied to the converter 2 very efficiently. Case B in FIG. 10 corresponds to this situation, and the number of ladles 3 is the number of payout pits + 1, and three ladles 3 are used. As a result, the crane cycle is shortened to 31 minutes / time while the conventional (case A) cycle time is 33 minutes / time.

  Also in the present desulfurization treatment, similarly to the first embodiment, the payout station 6 and the removal station 9 are provided apart from each other in the moving direction of the crane 4 by one crane or more. It is highly preferred to handle the ladle 3 with the crane 4 to allow simultaneous placement. Specifically, as shown in FIG. 4, the front blade 8F is placed at a position of the partition number 0 adjacent to the dispensing station 6A (separation number 1), and the hot metal dispensing to the two ladles is performed as the removal station 9. It is recommended to remove the hair simultaneously. Even if performed at the same time, the dispensation station 6A and the removal station 9 do not overlap with each other in plan view, so that the crane 4 does not come into contact.

In addition, the hot metal supply method to the converter of this invention is not limited to the said embodiment.
That is, the converter may be any one of a top blow converter, a bottom blow converter, and a top bottom blow converter. It can also be applied to furnace facilities.

It is a front schematic diagram of the converter equipment concerning a 1st embodiment. It is a plane schematic diagram of the converter equipment concerning a 1st embodiment. It is the Gantt chart in the converter equipment concerning 1st Embodiment, (a) is a prior art example, (b) is a thing of 1st Embodiment. It is a plane schematic diagram of the converter equipment concerning a 2nd embodiment. It is a plane schematic diagram of the converter equipment concerning a 2nd embodiment. It is a part of desulfurization process Gantt chart in the converter equipment of 2nd Embodiment. It is the figure which showed the relationship between a molten-steel production situation and the operating number of ladle. It is the figure which showed the relationship between the hot metal charging pitch in 1st Embodiment, and the operating number of ladle. It is the figure which showed the relationship between the hot metal charging pitch and operating number of ladle in 2nd Embodiment. It is the figure by which the operation performance in each embodiment was shown. It is the plane schematic of the converter equipment in a prior art example.

Explanation of symbols

1 Converter facilities 2 Converters (2A-2C)
3 Ladle 4 Crane (4A, 4B)
5 Chaos vehicle 6 Dispensing station (6A, 6B)
9 Removal station (9A, 9B)
14 Desulfurization station (14A, 14B)

Claims (3)

A converter, a ladle for charging hot metal into the converter, a discharge station where hot metal is discharged to the ladle, and a ladle in a predetermined cycle to carry the ladle into or out of the discharge station A converter facility with a handling crane,
The time interval at which the crane charges molten iron into the converter is defined as a molten metal charging pitch Pt, and the number of ladle operations is set according to the molten metal charging pitch Pt. When handling the pan with a crane and supplying hot metal to the converter,
The hot metal supply method to the converter, wherein the number of ladles operating is determined so as to satisfy the following formula including the hot metal charging pitch Pt and the crane net cycle time Cn.

ROUND_UP (Cn / R / Pt) ≤ Number of ladle operations ≤ ROUND_UP (Tn / R / Pt)
... (1)
Pt ≧ Cn / R (2)
Cn: Crane net cycle time
= Time that the crane is actually operating within one cycle of the crane (min / cycle)
Tn: Net cycle time
= Total time for each process such as hot metal discharge, desulfurization, etc.
+ Crane net cycle time Cn (min / cycle)
R: Number of crane bases (base)
Pt: Hot metal charging pitch (min / charge)
ROUND_UP (X): Rounds up X   The converter equipment has a standby station for repairing the ladle and collecting metal, and operates the ladle of the number of ladle operations set in claim 1 plus any of the ladle. A method of supplying hot metal to a converter, wherein one is arranged at the standby station.   The hot metal supply method for a converter according to claim 2, wherein the ladle at the standby station is heated.

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