JP2006322024A - Method for operating converter facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently operating a decarburization furnace regardless of the change of cycle times of converter processing conducted in a dephosphorization furnace and the decarburization furnace. <P>SOLUTION: The method is for operating the converter facility 1 provided with the dephosphorization furnace 9 for dephosphorization treatment and the decarburization furnace 10 for charging molten pig iron tapped out from the dephosphorization furnace and decarburizing the molten pig iron. The method includes starting the charge (#23) of the molten pig iron into the decarburization furnace later than the time of starting the charge (#7) of the molten pig iron into the dephosphorization furnace, by at least the total time T of a period of time necessary for charging the molten pig iron into the dephosphorization furnace and a period of time necessary for hanging up (#21) the ladle which accommodates the molten pig iron to be charged into the decarburization furnace. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for operating a converter facility that performs dephosphorization and decarburization using two converters.

Conventionally, the hot metal taken out from the blast furnace is charged into a kneading car (topy car) or a blast furnace pan, and the kneading car or blast furnace pan is charged with auxiliary materials to perform dephosphorization, desiliconization, and desulfurization. Then, a hot metal component adjustment process is performed in advance (a hot metal pretreatment process), and the hot metal is transferred to a converter process.
However, in recent years, a method of performing hot metal pretreatment in a converter process is becoming common.
In the method of performing the hot metal preliminary treatment in the converter process, the hot metal transferred by a kneading vehicle or the like is charged into a converter for dephosphorization, and dephosphorization is performed by blowing auxiliary materials and oxygen. Subsequently, the hot metal after dephosphorization is charged into a converter for decarburization, and decarburization is performed by blowing oxygen. Molten steel whose phosphorus concentration and carbon concentration are adjusted to predetermined values is formed into a slab or the like by a subsequent continuous casting process. A slab or the like is rolled and processed into a steel product such as a thick plate or a thin plate (rolling step).

In such a method of performing hot metal preliminary treatment in the converter process, each of the dephosphorization converter and the decarburization converter is operated efficiently with less waiting time (downtime). preferable. However, the total time required for the dephosphorization process (hereinafter, “total time required” may be referred to as “cycle time”) and the total time required for the decarburization process is as follows. There are many cases where they do not coincide with each other. For this reason, various methods for improving the efficiency of operation of each converter have been proposed.
For example, in Patent Document 1, in an apparatus having two converters, dephosphorization and decarburization are alternately performed in each converter instead of using a dedicated converter for either dephosphorization or decarburization. Thus, a method for improving the operating rate of the converter by shortening the waiting time due to the mismatch of the cycle times of the respective processes is disclosed.

In Patent Document 2, the cycle time of the dephosphorization process longer than the cycle time of the decarburization process is shortened by controlling the phosphorus content at the end point of the dephosphorization refining, thereby reducing the waiting time of the decarburization furnace. A method is disclosed.
By the way, in any of the dephosphorization process and the decarburization process, the cycle time is determined by the time required for individual operations such as hot metal charging, refining, refining, hot water, and exhausting. Moreover, the hot metal or molten steel discharge time is usually shortened by gradually expanding the discharge hole as the number of charges is increased, and the cycle times of the dephosphorization step and the decarburization step are gradually shortened as a whole. The hot metal or molten steel pouring time is managed by performing hole winding (repair of the pouring hole) after a predetermined number of charges have been accumulated or when it has become shorter than the predetermined time so as not to be extremely shortened.

However, the timing of the dephosphorization furnace and the decarburization furnace is different from each other because the degree of shortening differs depending on the extent of the enlargement of the tapping hole for each charge. . Further, due to the difference in the degree of shortening of the hot water time, the cycle times of both converters are repeatedly increased and decreased at different periods as a whole. Due to the different cycle time periods, for example, when one is immediately before the hole winding and the other is immediately after the hole winding, the difference in the cycle time between the dephosphorization step and the decarburization step is maximized. There is a case where one of these is made to wait.
JP 2002-363630 A JP-A-11-193414

The invention disclosed in Patent Document 1 equalizes operating time of each converter by alternately performing dephosphorization processing and decarburization processing with different cycle times in two converters. However, it is not clear whether the invention of Patent Document 1 can appropriately cope with the case where the cycle times of the dephosphorization furnace and the decarburization furnace change at different periods.
Patent Document 2 describes a dephosphorization method for shortening the time of the dephosphorization process. However, Patent Document 2 does not disclose effective knowledge for shortening the waiting time of the decarburization furnace when the cycle times of the dephosphorization furnace and the decarburization furnace change at different periods.

  The present invention has been made in view of the above-described problems, and in a converter process performed by a dephosphorization furnace and a decarburization furnace, the decarburization furnace is efficiently operated regardless of changes in these cycle times. Objective.

In order to achieve the above object, the present invention takes the following technical means.
That is, the operation method of the converter facility according to the present invention includes a dephosphorization furnace for performing a dephosphorization process, and a decarburization furnace for performing a decarburization process by charging molten iron discharged from the dephosphorization furnace. A method of operating the equipment, wherein the hot metal charging into the decarburization furnace is performed at least after the start of hot metal charging into the dephosphorization furnace and at least the time of hot metal charging into the dephosphorization furnace and the decarburization furnace. Start by delaying the total time with the time to lift the ladle containing the molten iron.
The lifting time refers to the time required to lift the ladle containing the hot metal discharged from the dephosphorization furnace and transport the hot metal into the decarburization furnace.

According to the present invention, since the operation of delaying the start of the hot metal charging into the decarburization furnace is planned in advance with respect to the hot metal charging into the dephosphorization furnace, for example, for introducing the hot metal into each converter There is no crane connection, and the hot metal discharged from the dephosphorization furnace can be charged without waiting for the decarburization furnace.
Preferably, the scrap is charged into the dephosphorization furnace before the dephosphorization treatment, and the scrap is charged into the decarburization furnace before the decarburization treatment.
According to the present invention, since the hot metal is charged into the dephosphorization furnace and the hot metal is charged into the decarburization furnace with a predetermined time shift, for example, the crane and scrap used for the hot metal charging are charged. Even when the crane used for the vehicle travels on the same rail, there is no waiting for work in any of the converters due to the fitting of the crane.

More preferably, the operation of the dephosphorization furnace is controlled so that the cycle time (T1) of the total treatment in the dephosphorization furnace and the cycle time (T2) of the total treatment in the decarburization furnace satisfy the formula (1). I do.
T1 ≦ T2 (1)
According to the present invention, the hot metal discharged from the dephosphorization furnace can be charged without waiting for the decarburization furnace, and the production of molten steel in the decarburization furnace can be performed efficiently.
Preferably, the management of the operation in the dephosphorization furnace is management of the hot metal discharge time from the dephosphorization furnace.

  According to the present invention, the cycle time of the dephosphorization furnace can be easily controlled to be shorter than the cycle time of the decarburization furnace, for example, by managing the specifications and the timing of the hole winding of the dephosphorization furnace. can do.

  According to the present invention, in a converter process performed by a dephosphorization furnace and a decarburization furnace, the decarburization furnace can be operated efficiently regardless of changes in these cycle times.

FIG. 1 is a schematic plan view of a converter facility in which the operation method according to the present invention is implemented, FIG. 2 is a schematic front view of the converter facility, and FIG. 3 is used for hot water from a dephosphorization furnace and charging to a decarburization furnace It is a figure which shows the mode of lifting of the prepared ladle.
1 and 2, the converter 1 includes a payout station 2 a, 2 b, a desulfurization station 3 a, 3 b, a removal station 4 a, 4 b, a slag dragger 5 a, 5 b, a first crane 6, a second crane 7, and a scrap crane 8. , A dephosphorization furnace 9 and a decarburization furnace 10.
In the following description, the right side of FIG. 1 may be referred to as a “lower process side”, the upper side as a “charging side”, the lower side as a “tapping side”, and the lateral direction as “crane traveling direction”.

  The payout stations 2a and 2b are provided in two locations below the horizontal reference plane HB in the crane traveling direction, and each of them has carts 12a and 12b on which ladles 11a and 11b can be loaded orthogonal to the crane traveling direction in FIG. It is accommodated in a movable direction. Dispensing stations 2a and 2b are places where the hot metal transported from the blast furnace by the kneading vehicle 13 is transferred to the ladles 11a and 11b. The transfer is performed by inclining the hot metal container of the kneading wheel 13 and pouring the hot metal into the ladles 11a and 11b loaded on the carts 12a and 12b.

Two desulfurization stations 3a and 3b are provided in the crane traveling direction below the traveling path of the crane. In the desulfurization stations 3a and 3b, a secondary raw material such as quicklime is introduced into the hot metal in the ladle 11a and 11b, and the sulfur content in the hot metal is reduced to a predetermined value or less by transferring sulfur in the hot metal to the slag layer. A desulfurization process is performed.
The degassing stations 4a and 4b are provided at two locations on the tapping side of the desulfurization stations 3a and 3b, corresponding to the desulfurization stations 3a and 3b, respectively. Ladles 11a and 11b that have been desulfurized at the desulfurization stations 3a and 3b are transferred to the removal stations 4a and 4b.

Each of the slag draggers 5a and 5b is disposed adjacent to the hot water outlet side of each of the degarding stations 4a and 4b. The slag draggers 5a and 5b are devices for scraping (snorkeling) the slag layer containing sulfur in the ladles 11a and 11b placed in the removal stations 4a and 4b.
The first crane 6 travels on a traveling rail 14 provided in the lateral direction (crane traveling direction) in FIG. 1, lifts the ladles 11a and 11b, and desulfurizes from the carts 12a and 12b of the dispensing stations 2a and 2b. Transport to the stations 3a, 3b, hot metal charging to the dephosphorization furnace 9 and the like are performed.

The second crane 7 has substantially the same size and lifting capacity as the first crane 6 and travels on the same traveling rail 14 as the first crane 6. The 2nd crane 7 lifts the hot metal ladle 15 which accommodates the hot metal discharged from the dephosphorization furnace 9, and performs hot metal insertion to the decarburization furnace.
The scrap crane 8 travels on the same traveling rail 14 as the first crane 6 and the second crane 7, lifts two scrap chutes 16 a and 16 b, and loads scrap into the dephosphorization furnace 9 and the decarburization furnace 10. I do. The scrap crane 8 is configured such that two scrap chutes 16a and 16b can be lifted simultaneously. The scraps 16a and 16b are loaded with scraps charged into the dephosphorization furnace 9 and the decarburization furnace 10 in a scrap yard (not shown).

Each of the dephosphorization furnace 9 and the decarburization furnace 10 is provided with means for blowing an inert gas from the furnace bottom in order to agitate the molten iron to be charged, and a lance (not shown) for blowing oxygen gas on the upper surface of the molten iron. It is configured to be inserted into the furnace.
The dephosphorization furnace 9 is installed at an appropriate interval from the desulfurization station 3b on the lower process side of the desulfurization station 3b. Here, the appropriate interval means that the second crane 7 can be retracted when the first crane 6 is above the desulfurization station 3b and the scrap crane 8 is charging the dephosphorization furnace 9 with scrap. Refers to the interval.

  In the dephosphorization furnace 9, the hot metal charging, the dephosphorizing process, the tempering, the hot water, the waste pouring, and the scrap charging are operated as one cycle. The hot metal charging is an operation in which the hot metal desulfurized at the desulfurization stations 3 a and 3 b is charged into the dephosphorization furnace 9. The dephosphorization treatment is an operation in which the hot metal is reacted with oxygen gas while stirring together with a slag-forming material such as quicklime and scrap, and the contained phosphorus is transferred to the slag layer on the upper surface. Refining is an operation to suppress the formation of furnace slag after dephosphorization. The hot water is an operation of transferring the hot metal from the dephosphorization furnace 9 to the hot metal ladle 15, and the discharge is an operation of tilting the dephosphorization furnace 9 and discharging slag containing phosphorus. The scrap charging is an operation of putting scrap into the dephosphorization furnace 9 for the next dephosphorization process.

The decarburization furnace 10 is located on the lower process side of the dephosphorization furnace 9 when the first crane 6 is in a position where the hot metal can be charged into the dephosphorization furnace 9 (the charging side of the dephosphorization furnace 9). 7 is installed at intervals enough to allow hot metal to be charged into the decarburization furnace 10.
The decarburization furnace 10 is operated with one cycle consisting of hot metal charging, blowing, tempering, tapping, exhausting, and scrap charging. The decarburization furnace 10 is charged with the hot metal dephosphorized in the dephosphorization furnace 9, and a process for removing carbon from the hot metal (decarburization process, sometimes referred to as "blowing") is performed. In the decarburization furnace 10, the carbon contained in the hot metal reacts with the oxygen gas blown on the upper surface thereof to become carbon monoxide or carbon dioxide and is discharged out of the decarburization furnace 10.

Below the dephosphorization furnace 9, a track 18 for running a hot water receiving carriage 17 on which a hot metal ladle 15 for receiving hot metal discharged from the dephosphorization furnace 9 is placed is laid from the hot water side to the charging side. .
Next, the operation method of the converter facility 1 according to the present invention will be described based on the operations of the first crane 6, the second crane 7, and the scrap crane 8 related to the transportation of hot metal or the like.
In the following description, for the convenience of explaining the positions of the first crane 6, the second crane 7, and the scrap crane 8, the traveling rail 14 is divided into seven sections, and position numbers are given to the sections. For example, the section having the position number 1 in FIG. 1 is referred to as “position (1)”.

FIG. 4 is a Gantt chart showing the operation method of the converter facility 1 according to the present invention.
1 and 2, the first crane 6 places the empty ladle 11b on the carriage 12b of the dispensing station 2b at the position (2) (# 0). The carriage 12b moves in the dispensing station 2b to the charging side, and the molten iron is dispensed from the kneading vehicle 13 to the ladle 11b (# 1). The first crane 6 moves to the position (1), lifts the ladle 11a that has finished discharging molten iron from the kneading vehicle 13 (# 2), and transports it to the desulfurization station 3a in the same position (1). It is placed on a cart (not shown) that stands by (# 3).

In the desulfurization station 3a, the desulfurization process is performed on the hot metal in the ladle 11a (# 4). The ladle 11a after the desulfurization process (# 4) is transported to the removal station 4a by a trolley as it is, and scallop (slag layer scraping) is performed by the slag dragger 5a (# 5).
The first crane 6 transports the ladle 11a to the desulfurization station 3a (# 3), moves to the desulfurization station 3b, and lifts the ladle 11b that accommodates the molten iron that has already been desulfurized and slaughtered (# 6). . Here, the ladle 11b that accommodates the hot metal for which the roast has been finished is different from the ladle 11b that receives the hot metal discharge (# 1) from the kneading vehicle 13 at the payout station 2b. The first crane 6 stands by at the position (2) with the ladle 11b for containing the hot metal being lifted up until the next hot metal charging (# 7) into the dephosphorization furnace 9.

While the first crane 6 performs the above operation, the dephosphorization furnace 9 performs a dephosphorization process (# 8) and a subsequent tempering operation (# 9). At this time, in the decarburization furnace 10, the molten steel tapping (# 10) is finished, and waste and scrap charging are performed (# 11), and the second crane 7 performs hot metal charging for decarburization processing ( # 12). The hot metal charging (# 12) by the second crane 7 is performed after the scrap charging (# 11) while avoiding the contact with the scrap crane 8 at the position (5). In the decarburization furnace 10, blowing (# 13) is started immediately after the hot metal is charged.
Further, while the first crane 6 performs the above-described operation, the second crane 7 is placed on the hot water receiving carriage 17 that waits at the position (4) for the hot metal ladle 15 emptied by the hot metal charging (# 12). (# 14). The hot water receiving trolley 17 on which the hot metal ladle 15 is loaded moves from the charging side to the hot water side in preparation for the hot water from the dephosphorization furnace 9.

Referring to FIG. 3A, when the refining operation (# 9) in the dephosphorization furnace 9 is completed, the hot metal is discharged from the dephosphorization furnace 9 (# 15) and poured into the hot metal ladle 15.
In the dephosphorization furnace 9 where the hot water (# 15) is finished, the waste is discharged and the scrap is loaded by the scrap crane 8 (# 16). At this time, the second crane 7 moves to the position (3) in order to avoid fitting with the scrap crane 8 at the position (4) (# 17). The reason why the first crane 6 continues to stand by at the position (2) while lifting the ladle 11b that accommodates the hot metal is to enable the movement of the second crane 7 to the position (3).

  When the scrap charging (# 16) is completed and the scrap crane 8 moves to the lower process side than the position (5), the second crane 7 moves from the position (3) to the position (5). The first crane 6 can move to the position (4) by the movement of the second crane 7, and the hot metal charging (# 7) into the dephosphorization furnace 9 is performed at the position (4). Between the scrap charging (# 16) and the hot metal charging (# 7), it is time to retract the scrap crane 8 to the position (6) and retract the second crane 7 to the position (5). About 1 minute is set. This time is indispensable for avoiding the mating of the cranes when charging scrap into the dephosphorization furnace 9.

  The ladle 11b emptied by the hot metal charging (# 7) is transported to the paying station 2a (position (1)) by the first crane 6 and placed on the carriage 12a for discharging the hot metal from the kneading vehicle 13. (# 18). Next, the first crane 6 moves to the position (2), lifts the ladle 11b that accommodates the hot metal (# 1) that has been delivered at the delivery station 2b, and transports it to the desulfurization station 3b (# 19). Then, it is placed on a cart (not shown) that stands by (# 20). Thereafter, the first crane 6 moves to the position (1), lifts the ladle 11a after the end of the oyster (# 5), and inserts the hot metal into the dephosphorization furnace 9.

  At the end of the hot metal charging (# 7) into the dephosphorization furnace 9, the hot water receiving carriage 17 for loading the hot metal ladle 15 containing the hot metal in the hot water (# 15) has already been placed at the position (4). It is conveyed to the charging side of the dephosphorization furnace 9. The first crane 6 moves to the position (1) where the dispensing station 2a is located (# 18) after the hot metal is charged into the dephosphorization furnace 9 (# 7) (# 18). The second crane 7 evacuated to the position (5) at the time of charging the hot metal into the dephosphorization furnace 9 (# 7) moves to the position (4) and the hot metal ladle 15 as shown in FIG. Is waited for (# 21), discharge of slag in the decarburization furnace 10 (exhaust), and completion of scrap charging (# 22) performed in preparation for the next decarburization process.

When the charging of the scrap (# 22) is completed and the scrap crane 8 moves to the lower process side than the position (5), the second crane 7 moves to the position (5) and is shown in FIG. 3 (c). Thus, the hot metal is charged into the decarburization furnace 10 (# 23). When the hot metal charging (# 23) ends, the second crane 7 places the empty hot metal ladle 15 on the hot water receiving carriage 17 waiting at the position (4) (# 24). The subsequent operation of the second crane 7 is the same as the operation after hot metal charging (# 12) in the previous decarburization process described above.
Here, the operation of the scrap crane 8 will be described. The scrap crane 8 lifts the two scrap chutes 16a and 16b containing the scraps at a scrap yard (not shown), first moves to the position (4), and loads the scraps from the scrap chutes 16a into the dephosphorization furnace 9 ( # 16, # 25). After that, when the second crane 7 starts to lift the hot metal ladle 15 (# 21) at the position (4) after waiting at the position (6) and waiting for the hot metal charging (# 7) to the dephosphorization furnace 9. Move to position (5) and charge scrap into decarburization furnace 10 from scrap chute 16b (# 22).

In FIG. 4, the required time (cycle time) of all processes from hot metal charging (# 7) to scrap charging (# 25) in the dephosphorization furnace 9 is 21 minutes (including the time adjustment of 1 minute in the middle) Min), the required time (cycle time) of all processes from hot metal charging (# 12) to scrap charging (# 22) in the decarburization furnace 10 is 23 minutes. The time required for individual operations in the dephosphorization furnace 9 and the decarburization furnace 10 is as shown in FIG.
As can be seen from FIG. 4, in the operation method of the converter 1 according to the present invention, the hot metal charging (# 23) into the decarburization furnace 10 is started from the start of hot metal charging (# 7) into the dephosphorization furnace 9. The first crane 6 and the first crane 6 are started by delaying the total time T of the hot metal charging time in the dephosphorization furnace 9 and the time for lifting the hot metal ladle 15 containing the hot metal charged in the decarburization furnace 10. The work using the two cranes 7 and the arrangement of the hot metal ladle 15 for receiving the hot metal discharged from the dephosphorization furnace 9 can be performed smoothly. In particular, since a series of operations from hot metal charging (# 12) to scrap charging (# 22) in the decarburization furnace 10 is continuously performed without waiting time, the decarburization furnace 10 can be operated efficiently. it can.

Actually, the cycle times of the respective processes of the dephosphorization furnace 9 and the decarburization furnace 10 are not constant as shown in FIG. 4, but each fluctuates, and the main factor of the fluctuation is hot metal or molten steel. Fluctuations in the hot spring time.
FIG. 5 is a Gantt chart when the cycle time of the dephosphorization process is longer than the cycle time of the decarburization process. Each cycle time in FIG. 5 is 23 minutes for the dephosphorization process and 22 minutes for the decarburization process. As can be seen from FIG. 5, even when the cycle time of the dephosphorization process is longer than the cycle time of the decarburization process, the start of the hot metal charging (# 27) to the decarburization furnace 10 is dephosphorized. In order to accept the hot metal discharged from the dephosphorization furnace 9 and the operation using the first crane 6 and the second crane 7 by delaying the hot metal charging (# 26) to the furnace 9 for a predetermined time. The hot metal ladle 15 can be arranged smoothly. Therefore, the dephosphorization furnace 9 can perform the dephosphorization process in a cycle in which about 1 minute, which is indispensable for avoiding the connection of each crane, is added to the cycle time. Further, the operation of the decarburization furnace 10 can be repeated with a minimum waiting time (# 28) that matches the cycle time of the dephosphorization furnace 9, and the decarburization furnace 10 can be operated efficiently. Can do.

  FIG. 6 is a diagram showing an example of the management of the tapping time in the dephosphorization furnace 9 and the decarburization furnace 10. The number of charges in FIG. Usually, the hot water time is slightly shortened as the number of hot water is repeated. This is because the refractories in the tapping holes of the dephosphorization furnace 9 and the decarburizing furnace 10 are scraped by hot metal (molten steel) during tapping, and the tapping holes gradually increase. Further, in FIG. 6, the dephosphorization furnace 9 has a lower degree of reduction of the hot water per charge than the decarburization furnace 10 because the hot metal discharged from the dephosphorization furnace 9 is hotter than the molten steel of the decarburization furnace 10. This is due to the low temperature and minor damage to the refractory in the tap hole.

  In the operation of the converter facility 1, when the hot water discharge time becomes shorter than a predetermined length, a pipe formed of a refractory is filled in the hot water discharge hole (hereinafter, this operation may be referred to as “hole winding”). Management to return the time to the original time. For example, as shown in FIG. 6, the dephosphorization furnace 9 performs hole winding when the tapping time reaches 4 minutes, and the decarburization furnace 10 performs hole winding when the tapping time reaches 3 minutes 30 seconds. is there. The hole winding timing of the dephosphorization furnace 9 and the decarburization furnace 10 is determined by the following equation (1): the cycle time (T1) of the entire process in the dephosphorization furnace 9 and the cycle time (T2) of the entire process in the decarburization furnace 10 It is preferable to manage so as to satisfy.

T1 ≦ T2 (1)
In the example of FIG. 4, the cycle time of the dephosphorization process is 21 minutes and the cycle time of the decarburization process is 23 minutes. If it does so, it is not necessary to set waiting time in a decarburization process, and the decarburization furnace 10 can be operated efficiently. In the present embodiment, the hot water discharge time of the dephosphorization furnace 9 is controlled to 5 minutes to 3 minutes 30 seconds.
Next, the operation method of the converter equipment 1 when the tapping time in the dephosphorization furnace 9 and the decarburization furnace 10 fluctuates within the management range of FIG. 6 will be described.

  FIG. 7 shows a case where the tapping time (# 31) of the dephosphorization furnace 9 is 5 minutes, the upper limit of management in FIG. 6, and the tapping time (# 32) of the decarburization furnace 10 is 4 minutes, the lower limit of management in FIG. It is a Gantt chart. In FIG. 7, the time required for each work other than the hot water (# 32) of the decarburization furnace 10 is the same as that in FIG. In FIG. 7, the hot water (# 32) time in the decarburization furnace 10 is shortened, whereas the hot metal charging (# 7) and dephosphorization (# 8) of the dephosphorization furnace 9 in FIG. Corresponding without waiting time. As can be seen from FIG. 7, the hot metal charging (# 33) into the decarburization furnace 10 from the start of the hot metal charging (# 34) into the dephosphorization furnace 9, Starting from the hot metal charging (# 33) in the decarburization furnace 10 to the scrap charging (# 35) by delaying the total time TA with the time for lifting the hot metal ladle 15 containing the hot metal charged in the decarburization furnace 10 ) Can be performed continuously without waiting time, and the decarburization furnace 10 can be operated efficiently.

FIG. 8 is a Gantt chart when the tapping time (# 41) of the dephosphorization furnace 9 is the control lower limit of 3 minutes 30 seconds, and the tapping time (# 42) of the decarburization furnace 10 is the control upper limit of 7 minutes. is there. Also in the case of FIG. 8, the hot metal charging (# 43) start to the decarburization furnace 10 is started from the start of hot metal charging (# 44) to the dephosphorization furnace 9 to the dephosphorization furnace 9. By delaying the total time TB of the time and the time for lifting the hot metal ladle 15 containing the hot metal charged in the decarburization furnace 10, the decarburization furnace 10 has a waiting time as in the case of FIGS. 4 and 7. And can be operated efficiently.
That is, in the present embodiment, the subsequent work of the dephosphorization furnace 9 is performed by delaying the start of the hot metal charging into the decarburization furnace 10 by a predetermined time from the start of the hot metal charging into the dephosphorization furnace 9. And the subsequent operations of the decarburization furnace 10 can be performed with an appropriate time difference, and the fitting of each crane can be minimized. As a result, the decarburization furnace 10 can perform a series of operations without setting a waiting time, and can operate the decarburization furnace 10 efficiently.

Next, the case where the converter equipment 1 is operated by a method different from the operation method according to the present invention will be described.
9 is a Gantt chart in the case where the hot metal charging into the decarburization furnace 10 is started after the scrap is charged into the dephosphorization furnace 9, and FIG. FIG. 11 is a Gantt chart in the case where the hot metal charging into the decarburization furnace 10 is started after the hot water from the dephosphorization furnace 9 is started. These figures are presented for comparison with the present embodiment shown in FIG.

  When the hot metal charging (# 52) is started into the decarburization furnace 10 after the scrap charging (# 51) into the dephosphorization furnace 9 shown in FIG. 9, the second crane 7 is in the hot metal ladle 15 at the position (4). Is moved to position (5) after lifting (# 53). The hot metal charging (# 54) into the dephosphorization furnace 9 by the first crane 6 is kept waiting for about 4 minutes. The time from the hot metal charging (# 55) of the dephosphorization furnace 9 to the next hot metal charging (# 54) is 21 minutes plus 4 minutes for a total of 25 minutes. For this reason, the decarburization furnace 10 having a cycle time of 23 minutes requires a waiting time of 2 minutes that was not necessary in the present embodiment.

When starting the hot metal charging (# 62) into the decarburization furnace 10 after the discharge (# 61) in the dephosphorization furnace 9 shown in FIG. 10, avoid the contact between the scrap crane 8 and the second crane 7. Therefore, it is necessary to wait for the scrap charging (# 63) to the dephosphorization furnace 9 during the hot metal charging (# 62) to the decarburization furnace 10, and from the hot metal charging (# 64) of the dephosphorization furnace 9. The time until the next hot metal charging (# 65) is 30 minutes. If it does so, the substantial cycle time of the decarburization furnace 10 will also be 30 minutes, and the decarburization furnace 10 needs the waiting time of 7 minutes.
In the case where the hot metal charging (# 72) is started into the decarburization furnace 10 before the discharge (# 71) in the dephosphorization furnace 9 shown in FIG. 11, as in the case of FIG. In order to avoid mating with the crane 7, scrap charging (# 73) into the dephosphorization furnace 9 must be performed after hot metal charging (# 72) into the decarburization furnace 10. Therefore, the interval from the hot water (# 74) to the hot metal charging (# 75) to the dephosphorization furnace 9 becomes longer, and the hot metal charging (# 76) of the dephosphorization furnace 9 to the next hot metal charging (# 75). It will take 28 minutes. Therefore, the decarburization furnace 10 having a cycle time of 23 minutes requires a waiting time of 5 minutes.

FIG. 12 is a table comparing the time from the start of the hot metal charging in the decarburization furnace 10 to the start of the subsequent hot metal charging from the respective Gantt charts shown in FIGS. 4 and 9 to 11. The case where no scrap is charged in the dephosphorization furnace 9 is also shown. As can be seen from FIG. 12, the hot metal charging into the decarburization furnace 10 takes time for hot metal charging into the dephosphorization furnace 9 and time for lifting the hot metal ladle 15 containing hot metal charged into the decarburization furnace 10. In the case of starting after delaying the total time, the decarburization furnace 10 can be operated more efficiently than the timing of the hot metal charging into other decarburization furnaces 10.
As described above, in the operation method of the converter facility 1 shown in FIGS. 9 to 11, it is difficult to perform each operation of the decarburization furnace 10 smoothly and continuously. Therefore, any work in the decarburization furnace 10 must be waited. On the other hand, in the operation method according to the present invention, as shown in FIG. 4, each operation of the decarburization furnace 10 can be performed smoothly and continuously, and the decarburization furnace 10 can be operated efficiently. it can.

In the above embodiment, an operation in which scrap is not charged in the dephosphorization furnace 9 or an operation in which scrap is charged in the dephosphorization furnace 9 and no scrap is charged in the decarburization furnace 10 may be performed. Even in that case, according to the operation method of the converter according to the present invention, a series of operations from hot metal charging to scrap charging in the decarburization furnace 10 is performed very smoothly, and the decarburization furnace 10 has no waiting time. It is operated efficiently.
The present invention is not limited to the above-described embodiment. For example, the present invention can be applied to converter facilities having different working times for the respective operations in the dephosphorization furnace 9 and the decarburization furnace 10. it can. Further, according to the present invention, when the cycle times of the dephosphorization step and the decarburization step have periods, and these periods are different from each other, the decarburization furnace 10 can be operated efficiently. It does not assume that the time changes. The present invention can also be applied to a converter facility where the cycle time of the process does not change, and an efficient operation of the decarburization furnace can be realized.

  INDUSTRIAL APPLICABILITY The present invention can be used for increasing the efficiency of operation of converter equipment that performs dephosphorization treatment and decarburization treatment in separate converters.

It is a plane schematic diagram of the converter equipment where the operation method concerning the present invention is carried out. It is a front schematic diagram of converter equipment. It is a figure which shows the mode of lifting of the ladle prepared for the charging to a decarburization furnace. It is a Gantt chart which shows the operation method of the converter equipment which concerns on this invention. It is a Gantt chart in case the cycle time of a dephosphorization process is longer than the cycle time of a decarburization process. It is a figure which shows the example of management of the tapping time in a dephosphorization furnace and a decarburization furnace. It is a Gantt chart when the hot water discharge time of a decarburization furnace is a control minimum. It is a Gantt chart when the tapping time of the dephosphorization furnace is the lower control limit and the tapping time of the decarburization furnace is the upper management limit. It is a Gantt chart at the time of starting the hot metal charging to a decarburization furnace after the scrap charging to a dephosphorization furnace. It is a Gantt chart at the time of starting the hot metal charging to a decarburization furnace after the exhaust operation in a dephosphorization furnace. It is a Gantt chart at the time of starting the hot metal charging to a decarburization furnace after the hot water from a dephosphorization furnace. It is the table | surface which compared the time from the hot metal charging start of a decarburization furnace to the start of the next hot metal charging by the difference in the hot metal charging time to a decarburization furnace.

Explanation of symbols

1 Converter 9 Dephosphorization furnace 10 Decarburization furnace 15 Hot metal ladle

Claims (4)

A dephosphorization furnace for performing a dephosphorization process, and a method for operating a converter facility including a decarburization furnace for performing a decarburization process by charging hot metal discharged from the dephosphorization furnace,
The hot metal charging into the decarburization furnace is performed after the start of the hot metal charging into the dephosphorization furnace, at least the time of the hot metal charging into the dephosphorization furnace and the hot metal charged into the decarburization furnace. A method of operating a converter facility, characterized by starting with a delay of a total time with the time for lifting the pan. Before the dephosphorization treatment, the scrap is charged into the dephosphorization furnace,
The method of operating a converter facility according to claim 1, wherein scrap is charged into the decarburization furnace before the decarburization treatment. The operation of the dephosphorization furnace is managed so that the cycle time (T1) of the total treatment in the dephosphorization furnace and the cycle time (T2) of the total treatment in the decarburization furnace satisfy the formula (1). The operating method of the converter equipment of Claim 1 or Claim 2 characterized by the above-mentioned.
T1 ≦ T2 (1) The operation method of the converter equipment according to claim 3, wherein the management of the operation in the dephosphorization furnace is management of a hot metal discharge time from the dephosphorization furnace.

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