JP4057005B2 - Converter operation method - Google Patents

Description

  The present invention relates to a method of operating a converter when efficiently using a plurality of converters.

As is well known, in the converter process, hot metal is charged into the converter, dephosphorization and decarburization are performed by adding auxiliary materials and blowing oxygen, and the phosphorus concentration and carbon concentration reach predetermined values. Is producing molten steel.
FIG. 11 shows a conventional converter facility, which includes a converter, a ladle that supplies hot metal to the converter, and a crane that conveys the ladle. There were three converters in total, two of them were in operation, and the remaining one was in a dormant state.
In detail, since the hot metal is charged into the converter, the inner wall is always exposed to high temperature, and the refractory bricks constituting the inner wall are gradually melted. That is, the converter has a furnace body life in which the refractory bricks melt and lose the function of the converter itself. It is impossible to operate the converter over a long period of time beyond this life, and after the converter has been operating for a certain period of time, a large-scale repair, such as replacing the refractory bricks in the converter, Is to be performed. The one converter that was out of service was in such a furnace repair operation and in the subsequent stop state.

  FIG. 12 shows an operation schedule in the converter equipment of FIG. 11, and FIG. 12 (a) shows converter operation periods (that is, converter life) for three converters A, B, and C. And the schedule of furnace repairs are shown. As in this schedule, the two converters within the converter life were refined with hot metal, and the remaining one converter was repaired and closed. Assuming that converter A and converter B are in operation as indicated by P in the figure, it is assumed that it is time to replace the refractory bricks attached to the inner wall of converter A. In such a case, the converter A enters the furnace repair work, and instead, the converter C that has been closed until now is put into operation. Then, even if the furnace repair of the converter A was completed, the converter A was considered as a backup, and was not in operation, but was in a closed state. In other words, if one of the two converters B, C used is out of order or needs to be repaired, the converters B, C are stopped and are currently closed. The converter A was restarted.

  FIG. 12 (b) shows the charge status at each converter B, C when two converters B, C are operating. Converter charge refers to a series of processes in which molten iron is charged into the converter, blown into the molten iron, and the produced molten steel is discharged. The time from the end to the end is called steelmaking time. Usually, about 5000 charges are performed within one converter life. As shown in the figure, if necessary, there is a converter downtime between each charge, and this time is a simple repair that greatly improves the furnace life by spraying fireproof repair material on the inner wall of the converter. It is time to perform “repair”.

If the converter life is converted to days, it is roughly around 150 days, and the furnace repair is around 20 days. On the other hand, the steelmaking time for one charge in the converter is about 35 minutes, and the repair of the converter has 10 minutes to several hours. In view of this, FIG. 12 is summarized as follows. FIG. 12 (a) shows the converter process divided into a furnace repair period and an operation period as seen macroscopically on a daily basis. Yes, FIG. 12 (b) shows the converter process divided into charge and repair period when viewed in a microscopic (microscopic) manner in time units.
As can be seen from the above, in conventional conventional converter facilities, only two converters are always in operation from the macro and micro perspectives, and the remaining one is closed as a backup. It is normal to be. Therefore, peripheral equipment of the converter, for example, exhaust gas treatment equipment and oxygen supply equipment, has only the ability to blow only two converters.

In such a converter facility, the techniques of Patent Document 1 and Patent Document 2 have already been disclosed for efficiently operating two converters.
In the technique of Patent Document 1, the molten metal dephosphorized and refined in one converter is received in a receiving hot pot, and the hot pot is transported to the other one through the work floor opening, where decarburization refining is performed. In addition to reducing the slag removal time in dephosphorization refining and reducing the dephosphorization refining time and decarburization refining time to the same extent, the play time of the decarburization refining furnace is eliminated as a whole. It improves the steelmaking efficiency. In other words, it is a technique for increasing the steelmaking efficiency by making the charge time in one converter the same as the charge time in another converter.

In the technology of Patent Document 2, the operation of opening the flue damper of the converter that starts blowing and the operation of closing the damper of the flue of the converter that has finished blowing are performed in one stage in two converters. The damper operation is performed simultaneously and in parallel to shorten the wind stop time at the time of switching, and relates to a method for operating the damper of the flue at the time of charge switching of the converter.
Japanese Patent No. 3486886 JP-A-6-65653

In the converter equipment mentioned above, when thinking about increasing the production capacity of molten steel, not only two converters will be operated, but another converter that is in a closed state will be operated, The converter should be operating at the same time. However, since the converter peripheral equipment has only the ability to operate two converters, it is simply impossible to operate three simultaneously.
In order to solve this problem, even if attention is given to Patent Document 1 and Patent Document 2 described above, these technologies are intended to increase efficiency in the operation of two converters after microscopically viewing the converter process. Even if this technology is applied, it is difficult to realize the operation of three converters in a macro view and to greatly improve the molten steel production capacity.

  Therefore, in view of the above problems, the present invention is a converter facility having a converter peripheral facility that has only the ability to blow down two converters, and the operation schedule of the simultaneous operation status of the three converters is used. The object is to provide a converter operating method that can be incorporated.

In order to achieve the above object, the present invention takes the following technical means.
That is, the technical means for solving the problems in the present invention include three converters that perform hot metal blowing, and converter peripheral equipment that has the capability of blowing up to two converters. In order to operate the three converters without exceeding the capacity of the converter peripheral equipment with the converter equipment that has, before the end of the blowing in the first converter, the order of charge of each converter The second converter is set to start blowing, and the third converter is started before the second converter is finished and before the first converter It is set between the end of the previous blowing and the start of the next blowing.

We thought to increase the production capacity of molten steel with a converter facility that has three converters that perform hot metal blowing and peripheral equipment that has the capability of blowing up to two converters. In this case, as described above, it is preferable that the three converters are operated substantially at the same time (3/3 operation). However, since the converter peripheral equipment has only the capability of blowing two converters, it is impossible to simply operate three units simultaneously.
Therefore, as a result of studying various operation situations, the inventor of the present application, as shown in FIG. 1 (a), is in a situation where three converters are operating in a macro manner, as shown in FIG. 1 (b). Microscopically, the technical idea that two converters can be blown and charged one after another so that productivity can be greatly improved without exceeding the capacity of peripheral equipment. I came to get.

  That is, as shown in FIG. 1 (b), the charging order of the converter A and the converter B is changed to the converter B (first converter) before the blowing in the converter A (first converter) is completed. By setting so as to start blowing in the converter (2), the situation is that both perform blowing simultaneously. Furthermore, by starting the blowing of the converter C (third converter) before the end of the blowing in the converter B, the converter B and the converter C are simultaneously blown. . In addition, since the start of blowing of the converter C is set between the end of the previous blowing in the converter A and the start of the next blowing, in other words, when the converter A is not blowing, The converter A and the converter C are not in a state where they are simultaneously blown, and as a whole, the three converters A, B, C are not in the state of blowing at the same time.

By adopting such an operating situation, it becomes possible to operate three converters at the same time macroscopically without exceeding the capacity of the peripheral equipment of the converter, and greatly improve the molten steel productivity. be able to.
Preferably, a situation in which there is one each of the other two converters at the start of the next blowing operation between the previous blowing start of the first converter and the next blowing start is referred to as the operating state sequentially. It is good that at least one of the third converters has the sequential operation status.
In addition, the ratio of the number of charges of the converter in the sequential operation status to the total number of charges is the sequential operation ratio of the converter, and the sequential operation ratio of the converter is 40% to 95%. It is good to operate three converters.

The situation in which the other two converters start blowing between the start of blowing and the end of blowing of one converter is defined as the sequential operation of one converter, and this sequential operation status The ratio of the number of charges in the converter to the total number of charges is the sequential operation ratio of the converter, and the sequential operation ratio of the converter is preferably 40% to 95%. It is based on the grounds described below.
That is, after defining the sequential operation ratio as described above, when looking at FIG. 2 and FIG. 3 depicting FIG. 1B in detail, the situation where the sequential operation ratio is high corresponds to the P part in FIG. Converters A, B, and C perform blowing without any delay. On the other hand, the operation ratio of the Q section is low sequentially, and the converter A and the like have a long pause time. Considering this, the operation ratio increases sequentially, that is, the converter charge continues in sequence, so that the three converters are fully operating without waiting time, and the molten steel productivity of the converter equipment is increased. Become very good.

However, in actual converter operation, repair work such as metal bulging, hole winding, and refractory repair for the converter is performed as needed. These operations are indispensable for stable operation of the converter, but if the sequential operation ratio of the converter is large, it will be difficult to secure time for performing such repair work, and conversely, the productivity of molten steel will decrease. Become.
Therefore, the applicant of the present application simulated the change in hot metal productivity when the operating ratio was sequentially changed to obtain an optimum sequential operating ratio. The results are shown in FIGS. FIG. 4 shows the calculation results, and FIG. 5 is a graph based on the calculation results.

Fig. 5 shows the molten steel productivity when the operating ratio is changed one after another under three different conditions of the hot metal supply time to the converter determined by the capacity of the crane: 10 minutes, 15 minutes and 20 minutes. Changes are described. In addition, the steelmaking time in each condition is 35 minutes, 35 minutes, and 40 minutes.
The horizontal axis in the figure is the sequential operation ratio of the converter, the vertical axis shows the molten steel productivity, the number of charges per hour, the result of the hot metal supply time 10 minutes is graph I, 15 minutes Graph II, 20 minutes is graph III. The short hot metal supply time means that the hot metal supply capacity of the crane is large and that much hot metal can be supplied with respect to the processing capacity of the converter, and the slope of graph I is the largest.

Graph II is a calculation result in the case of having a normal crane capacity. In the graph, the molten steel productivity takes the maximum value when the operation ratio is sequentially 75%. The inventor of the present application thinks that, when ensuring about 95% of the maximum value is always secured, the molten steel productivity becomes very good over the entire converter operation, and the sequential operation ratio of the converter is 40% to 95%. %. More preferably, the range is 50% to 90%.
The situation shown in Graph III is when the hot metal supply capacity of the crane is smaller than the processing capacity of the converter itself. In this case, even if the operating ratio is increased, the hot metal productivity will not be improved. It is a result to fall to.

Graph I is when the crane's supply capacity is very large. Since the hot metal supply capacity of the crane is usually designed for the operation of two converters, it is rare that it will be like this case, but even in this case, the operation ratio is gradually increased from 40% to 95%. If it is kept at, it is possible to keep the molten steel productivity high.
Further, the technical means for solving the problems in the present invention are: first → second → to secure a repair time required for performing “repair” which is a simple repair to the inner wall of the converter. The operation order of the converter, which was the third, is reversed.

As mentioned above, converter repair work is indispensable for converter operation, and it is possible to produce molten steel by securing a repair period, which is the time for performing such repair, between each charge of the three converters. It becomes possible to perform repairs without lowering the performance.
FIG. 6 shows a state in which the repair period is secured in the converter A (first converter) by reversing the charging order of the three converters which have been first → second → third. ing.
That is, before the blowing in the converter A is completed, the blowing in the converter B (second converter) is started, and the blowing in the converter C (third converter) is started. The start is before the end of blowing of the converter B and after the end of blowing of the converter A.

Here, when it becomes necessary to perform repair work in the converter A (P in FIG. 6), after the converter C is charged, the converter B is charged instead of the converter A, and the converter B is blown. Before finishing, the blowing of the converter A is started. (C0 → B1 → A1). Thereafter, the three converters are charged in the reverse order of the converter C, the converter B, and the converter A (C1 → B2 → A2, that is, third → second → first).
By doing in this way, it becomes possible to ensure a long downtime of the converter A between the blowing A0 and A1, and by making this downtime a repair period, Even if the furnaces are operated sequentially and repaired, the molten steel productivity can be kept high.

In addition, it is very preferable that the repair time is within a range of T / 4 to 3T (T is a steelmaking time). The reason will be described below.
FIGS. 8 and 9 show the results of simulating the degree of extension of the converter life (repair effect) and the time required for collecting the metal when the repair time varies from about 5 to 600 minutes. Yes. FIG. 8 shows the calculation results, and FIG. 9 is a graph of the calculation results. In all calculations, the steelmaking time is 35 minutes and the hot metal supply time at the crane is 15 minutes.
The horizontal axis in FIG. 9 is the repair time converted in terms of the steelmaking time T, and the vertical axis shows the repair effect and the bullion collecting time.

Graph I in the figure shows the change in the repair effect. By making the repair time longer, the repair work can be performed reliably, and the number of charges extending in one repair increases. Has been. Increasing the repair time to about 0.25 T (T / 4) extends the converter life by about 3 charges. On the other hand, if the repair time is about 0.4 T or more, the repair effect = 5.0 charge will not increase any more.
Graph II shows the change in the time required for collecting bullion. When the repair time is 3T or less, the bullion collecting time is zero, and when the repair time is 3T or more, the bullion collecting time is generated. This reflects that the longer the repair time, the lower the temperature of the converter itself, and the greater the possibility that metal will adhere to the converter inlet. Therefore, it is not a good idea to make the repair time extremely long. As can be seen from the graph II, if the repair time is set to 3T or less, the work time for the bullion collecting operation can be reduced.

  In view of these matters, by setting the repair time within the range of T / 4 to 3T, it is possible to prevent an increase in the time for the bullion collecting operation while making the repair effect appropriate.

  According to the present invention, it is possible to efficiently operate three converters in a converter facility having a converter peripheral facility having only the capability of blowing two converters.

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.
The converter equipment 1 of this embodiment is substantially the same as the conventional example shown in FIG. 11, and includes three converters 2, a ladle 3 that supplies hot metal to these converters 2, and this ladle 3. It has two cranes 4 to convey. Further, each of the three converters 2 is provided with an exhaust gas treatment facility 5 that collects exhaust gas generated by blowing and removes harmful substances or collects carbon monoxide. An oxygen supply facility 6 for supplying oxygen to the converter 2 is provided. The oxygen supply equipment 6 can supply twice the amount of oxygen used by one converter for blowing, and the exhaust gas treatment equipment 5 can supply CO gas discharged from the two converters 1. Has the ability to collect. That is, the converter peripheral equipment 7 composed of the exhaust gas treatment equipment 5 and the oxygen supply equipment 6 has the ability to simultaneously perform blowing in the two converters 2, and the three converters 2 Simultaneous blowing in is impossible.

The present invention, as shown in FIGS. 1 to 3, in the converter equipment 1, defining the operation process in units of days as macroscopic, and in units of time as microscopic, Although three converters 2 are in operation, microscopically, two converters 2 are blown and charged sequentially so that the capacity of the converter peripheral equipment 7 is increased. It is intended to greatly improve productivity without exceeding.
Explaining each process in the converter equipment 1 in detail, first, the hot metal in the ladle 3 is conveyed by the crane 4 and charged into the converter 2. Specifically, the converter 2 is tilted, and scraps and the like are charged into the furnace, and then molten iron is poured.

Thereafter, in order to remove mainly phosphorus P in the hot metal and make carbon C suitable, a lance (not shown) is inserted from the furnace port of the converter 2 and is brought close to the upper surface of the hot metal, and oxygen gas is blown. At the same time, blowing (refining) is started while the hot metal is stirred from the bottom of the furnace. At the same time, the coolant such as the slag forming and iron oxide Fe _x O _y, such as lime CaO, i.e. by turning on the auxiliary materials, phosphorus P is shifted to the slag phase to react with the entered oxygen, above the hot metal Laminate in a floating state.
Thus, the molten iron is charged into the converter 2 and the molten steel is blown and the molten steel is adjusted in composition, and a series of processes in which the molten steel is discharged from the converter 2 is referred to as “charging”. The steelmaking time for one charge is about 35 minutes.

  On the other hand, the inner wall of the converter 2 is always exposed to a high temperature by the hot metal, and the refractory bricks constituting the inner wall are gradually melted down. Therefore, the converter 2 has a “lifetime” in which the refractory bricks melt and lose the function of the converter itself. Since it is impossible to operate the converter 2 over a long period of time beyond this life, the converter 2 operates in the converter 2 after being operated for a certain period as shown in FIG. Large-scale repairs, such as replacing refractory bricks, "furnace repairs" are being carried out. When the life of the converter 2 is converted to days, it is roughly 150 days, but the furnace repair is about 20 days. Moreover, it is normal that about 5000 charge is performed within one converter lifetime.

In addition, in normal converter operation, repair work such as metal removal, hole winding, and refractory repair for the converter 2 is performed as needed. These operations are essential for stable operation of the converter 2. It is.
The bullion removing operation referred to here is an operation of removing the bullion because the molten iron is fixed to the vicinity of the molten metal inlet of the converter 2 by slapping or the like. This is performed about once every 10 charges and has a time of about 30 minutes.
The hole winding operation is an operation of replacing the refractory bricks at predetermined intervals because the refractory bricks at the outlet of the converter 2 are gradually deteriorated by the molten steel. The hole winding operation is performed once for about 100 charges, and requires an operation time of about 60 minutes.

Repair of refractory bricks (refractories) is a simple repair that greatly improves the life of the furnace by spraying fireproof repair material on the inner wall of the converter 2, and is performed once every 10 charges. Repair takes about 30 minutes.
2 and 3 are detailed views of FIG. 1 (b), which are microscopic views of the operation status of the converter 2, and show the order of charging in the three converters 2 in the present embodiment. Is.
First, before the end of blowing in the first converter 2 (converter A), the second converter 2 (converter B) is set to start blowing, and the third converter Blowing start of the furnace 2 (converter C) is performed before the end of blowing in the second converter 2 and between the end of the previous blowing in the first converter 2 and the start of the next blowing. It is set.

Specifically, in the converter A, the hot metal charging is started before the time 0 min, and the blowing is started around the time 0 min. Blowing ends after 20 minutes, and then the molten steel is dispensed, and the steel output is completed after 30 minutes.
In the converter B, the hot metal charging is started before the time 10 minutes, and the blowing is started around the time 10 minutes. Blowing ends after 30 minutes, and then the molten steel is dispensed, and the steel output is completed after 40 minutes. As can be seen from the figure, the start of the blowing in the converter B is in the middle of the blowing of the converter A, and during the time of 10 min to 20 min, the blowing is performed in both the converters A and B. ing.

In the converter C, the hot metal charging is started before 20 minutes, and blowing is started around 25 minutes. Blowing ends after 45 minutes, and then the molten steel is dispensed, and the steel output is completed after 55 minutes. The start of blowing in the converter C is during the blowing of the converter B and after the end of the blowing in the converter A. That is, the order in which blowing is performed is A0->B0-> C0, and is lined up on the diagonally downward arrow in the figure.
Further, before the blowing in the converter C is completed, the hot metal charging into the converter A is started again, and the blowing is performed subsequently. Similarly, in the middle of blowing in the converter A, the blowing in the converter B is started. In the middle of the blowing of the converter B and after the completion of the blowing of the converter A, the blowing in the converter C is performed. Alchemy is to be started. That is, the order in which blowing is performed is A1 → B1 → C1, and is arranged on an arrow that is slanted to the right in the figure.

By doing in this way, in any phase (time), there are two converters 2 during blowing, which does not exceed the capacity of the converter peripheral equipment 7. However, when viewed macroscopically, as shown in FIG. 1A, it is a 3/3 unit operation period in which three units are operating at the same time, and the hot metal production capacity can be significantly improved. In FIG. 3, since the start of three blows is included in about 35 minutes, the converter 1 in the operational state has a production capacity of 3 charges in 35 minutes, that is, 5 charges in 1 hour. Will have.
When attention is paid to the charge including the blowing A0 in FIG. 3, the start of the blowing of the converter B and the converter C between the start of the blowing A0 and the start of the blowing A1 in the next charge. It can be seen that there is one start of blowing each. A charge under such circumstances is defined as a charge in a “sequentially operating converter”. In addition, the number of charges of the converters that are operating sequentially with respect to the total number of charges of the three converters 2 is defined as the “sequential operation ratio”.

As this sequential operation ratio increases, the three converters 2 are operating without waiting time, and theoretically, the hot metal production capacity is improved.
However, in reality, the time (period) for the above-mentioned “repair of the converter” is necessarily required, and when the sequential operation ratio of the converter 2 is large, it becomes difficult to secure these repair times, Molten steel productivity falls.
In the case of this embodiment, the sequential operation ratio of the three converters 2 is set between 40% and 95%, as is apparent from the graph II of FIG. 5 which is a simulation result of molten steel productivity. More preferably, it is in the range of 50% to 90%, and the maximum value of productivity can be obtained by sequentially setting the operation ratio to 75%.

Further, in the present embodiment, in order to reliably obtain such repair time, as shown in FIG. 6, by changing the operation order of the converter 2 that has continued from A → B → C from C → B → A, The converter A has time for repairs. That is, after operating the converter C, operating the converter B, and then operating the converter A, the time close to the steel making time for one charge in the converter A can be set in a non-operating state, and the period is It is set as repair time.
On the other hand, regarding the repair work of the converter 2, the converter 2 is not operated immediately after the repair, but is left for a predetermined period of time and the time required for the repair material sprayed to repair the inner wall reliably. It may be secured. This is called standing time. In addition, repairs beyond normal repairs may be performed and repair time may be required.

In order to secure these stationary time and repair time in the converter B, as shown in FIG. 7, the operation order of the converter 2 that has continued from A → B → C is temporarily changed to C → A and B is skipped. In the reverse order of C → B → A after that, the converter B is secured for repair, stationary, and repair time.
The repair time described above is within the range of T / 4 to 3T, as shown in FIG. 9, so that the repair effect can be made appropriate and an increase in the time for the bullion collecting operation can be prevented. It becomes like this. More preferably, the repair time is set to T / 4 to 1.5T.

The operation method of the converter 2 described above can also be applied to the converter facility 1 performing a so-called double slag method in which dephosphorization and decarburization are performed in one converter 2.
The double slag method is to perform a “dephosphorization step” for removing phosphorus P in the molten iron and a “decarburization step” for removing carbon in one converter 2.
In the dephosphorization step, a lance is inserted from the furnace port of the converter 2 and is brought close to the upper surface of the hot metal, and oxygen gas is blown. At the same time, refining (blowing) is performed while the hot metal is stirred from the bottom of the furnace. At the same time, the coolant such as the slag forming and iron oxide Fe _x O _y, such as lime CaO, i.e. by turning on the auxiliary materials, phosphorus P is shifted to the slag phase to react with the entered oxygen, above the hot metal Laminate in a floating state. Since this slag contains a lot of unreacted CaO, it has a dephosphorization ability.

Next, the slag produced by the dephosphorization process is discharged to the outside by tilting the converter 2 toward the furnace front side. The discharged slag is carried out by the transfer means arranged below the converter 2 (discharge process).
The converter 2 that has undergone the discharge process is returned to its original position again, and then proceeds to a decarburization process that mainly removes carbon C in the molten iron by blowing oxygen and adding auxiliary materials. After the decarburization step, the converter 2 is tilted so that the molten steel flows out from a steel outlet provided on the upper side of the converter 2. At that time, it is possible to leave the slag generated in the decarburization process, and the hot metal to be refined next is charged (charging process of the next charge). By doing so, it is possible to recycle slag having sufficient dephosphorization ability as the precharge slag and effectively use it, thereby reducing the amount of waste slag.

FIG. 10 employs the charge schedule of FIG. 3 for converters A and B performing the double slag method.
Since the double slag method only involves a processing time extension of about 8 minutes (EXT in FIG. 10) compared with the blowing process in the ordinary converter 2, the converter 2 is sequentially changed from A → B → C. Even if it is in operation, for example, the end of the last steel output in the converter A and the next hot metal charging are almost the same time, and both processes do not overlap.
When the operation method of the converter 2 described above is applied, the three converters 2 are almost in full operation, and the capacity of the charging crane 4 for charging the converter 2 with scraps or the like is You may not be able to keep up with the cycle. In such a case, the operation may be performed using the hot metal conveyed from the blast furnace without charging scrap into the converter 2.

Further, in the operation of the converter 2, there may be a failure of the converter peripheral equipment 7 such that the lance cannot be inserted from the loading port. In such a case, the repair may take a short time (about 30 minutes) or may take a relatively long time (for example, 5 hours or more).
Therefore, when the repair time of the converter peripheral equipment 7 is short, the repair time is reduced by, for example, reversing the charge order as described in the present embodiment after the 3/3 operation. If it is ensured and this repair time is used as the repair time of the converter peripheral equipment 7, it is very advantageous from the viewpoint of molten steel productivity.

On the other hand, when the repair time of the converter peripheral equipment 7 takes 5 hours or more, rather than securing the repair time in the reverse order or the like, the converter 2 corresponding to the repair is suspended and the same as in the repair of the furnace. It is advantageous from the viewpoint of molten steel productivity when the two converters 2 are in an operating state (2/3 operation). In order to secure the repair time for the converter peripheral equipment 7, the boundary of whether the converter 2 is operated by 3/3 or 2/3 is necessary for the temperature rise when the converter 2 is restarted. Preferably, about 3 hours are adopted, and “repair time = 3 hours” is set as the boundary value.
In addition, the hot metal supply method to the converter 2 of this invention is not limited to the said embodiment. Further, the converter 2 may be any one of a top blowing converter, a bottom blowing converter, and an upper bottom blowing converter.

The order of the converter operation concerning this invention is shown, (a) was seen macroscopically, (b) was seen microscopically. It is the figure which showed the order of the charge of a converter. It is the figure which showed the order of the charge of a converter. It is the simulation result of the relationship between the sequential operation ratio of a converter and molten steel productivity. It is the figure which showed the relationship between the sequential operation ratio of a converter, and molten steel productivity. It is the figure which showed the order of the charge of a converter (in the case of reverse order). It is the figure which showed the order of the charge of a converter (in the case of reverse order and stationary time). It is a simulation result of the relationship between repair time, repair effect and bullion collection time. It is the figure which showed the relationship between repair time, repair effect, and bullion taking time. It is the figure which showed the order of the charge of the converter at the time of using a double slag method. It is the front schematic of the converter equipment concerning the past and this invention. The order of the conventional converter operation is shown, (a) is a macro view, and (b) is a micro view.

Explanation of symbols

1 Converter 2 Converter 7 Converter peripheral equipment

Claims (5)

A converter facility that has three converters that perform hot metal blowing and converter peripheral facilities that are capable of blowing up to two converters.
In order to operate the three converters without exceeding the capacity of the converter peripheral equipment, the order of the charge of each converter is changed to the second converter before the blowing in the first converter is completed. Was set to start blowing at the end of the third converter, before the end of the blowing at the second converter and the end of the previous blowing at the first converter The operation method of the converter, which is set during the next start of blowing.   The situation in which the other two converters start blowing each time between the start of the previous one and the next start of the next converter is sequentially designated as the operating state, and the first to third converters The method of operating a converter according to claim 1, wherein at least one of the furnaces has the sequential operation state.   The ratio of the number of charges of the converter in the sequential operation state to the total number of charges is defined as the sequential operation ratio of the converter, and three converters are set so that the sequential operation ratio of the converter is 40% to 95%. The converter operation method according to claim 2, wherein the converter is operated.   In order to secure the repair time required for performing “repair”, which is a simple repair to the inner wall of the converter, the operation sequence of the converter, which is the first → second → third, is reversed. The operating method of the converter in any one of Claims 1-3 characterized by the above-mentioned.   The method for operating a converter according to claim 4, wherein the repair time is set within a range of T / 4 to 3T (T is a time for steelmaking).

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