JP7839399B2 - Method of supplying power to a mixed iron cart - Google Patents

Description

This invention relates, in particular, to a method for supplying power to a mixed iron truck that has stopped in an emergency.

When a torpedo truck or other metal mixing vehicle is loaded with molten iron from a blast furnace, and the vehicle stops due to an emergency such as a power outage, the temperature of the molten iron inside the furnace drops. After a certain period of time, the molten iron may solidify and adhere to the inside of the furnace. Such solidified molten iron deposits reduce the capacity of the furnace and, in some cases, may render the metal mixing vehicle unusable. Furthermore, when solidified molten iron adheres to the inside of the furnace, more energy is required to tilt it than when only liquid molten iron is being tilted. Additionally, because the weight balance is disrupted by such adhesion, attempting to tilt the furnace body by driving the tilting mechanism to discharge the molten iron carries the risk of the metal mixing vehicle tipping over.

Therefore, if a molten iron truck is stopped for a certain period of time due to a power outage or other reasons, it is necessary to drive the tilting device at the stopping position to tilt the furnace body and discharge the molten iron there. However, normally, the tilting device of a molten iron truck is only driven at specific locations, such as when discharging molten iron into a ladle at a steelmaking plant. Therefore, the molten iron truck itself usually does not have a power supply to drive the tilting device, and in an emergency, it is not possible to tilt the furnace body at the stopping position.

On the other hand, as a technology for securing power in case of emergencies such as power outages, Patent Document 1 discloses a technology for pre-installing a storage battery (secondary battery) in a metal mixing truck. Furthermore, Patent Document 2 discloses an emergency charging system that supplies power to electric vehicles using a power supply train in the event of an emergency.

Japanese Utility Model Publication No. 63-79267 Japanese Patent Publication No. 2000-102102

However, the technology described in Patent Document 1 is a technology that generates electricity from the axle to charge and mainly operates control systems such as coupling parts, and it is difficult to supply enough power to operate the tilting device. Furthermore, installing a large-capacity emergency secondary battery on a molten iron truck requires securing a large separate space, and installing a secondary battery that is only used in infrequently, such as during emergencies, is not cost-effective. Also, the technology described in Patent Document 2 supplies power to enable an electric vehicle to travel to a charging station, and is not a technology that supplies the power necessary to tilt a furnace body containing several hundred tons of molten iron.

Furthermore, in the event of an emergency where the iron mixing truck stops, it might be conceivable to deploy a vehicle equipped with a large external battery to supply power to the truck and drive the tilting mechanism. However, this would be inefficient from a cost perspective, as the connection would require someone highly skilled in maintenance, and large external batteries are not used under normal circumstances.

In view of the aforementioned problems, the present invention aims to provide a method for supplying power to a mixed iron cart that is cost-effective and capable of supplying power to drive the furnace tilting device when the cart is stopped in an emergency.

The present invention is as follows:
(1)
A method for supplying power to a molten iron cart, comprising a furnace body that receives molten iron through a receiving port, and a tilting device for tilting the furnace body,
The tilting device is,
The system includes a tilting motor for tilting the furnace body, an electromagnetic brake and an eddy current brake for controlling the rotation of the furnace body, and a gear grease pump for circulating lubricating oil in a gearbox that controls the rotational speed of the tilting motor.
An electric vehicle capable of outputting the power necessary to drive the tilting device is brought close to the iron mixing vehicle, and the voltage from the secondary battery mounted on the electric vehicle is adjusted using a first DC-DC converter to a voltage to be input to the first DC-AC inverter.
A method for supplying power to a molten iron cart, characterized by adjusting the voltage, then using the first DC-AC inverter to convert from direct current to alternating current and supply power to the tilting motor, using the second DC-DC converter to supply direct current power to the electromagnetic brake and the eddy current brake, using the second DC-AC inverter to convert from direct current to alternating current and supply power to the gear grease pump , and tilting the furnace body to discharge the molten iron.
(2)
The method for supplying power to a molten iron cart according to (1) above, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body so that the receiving port is in a position lower than directly above, thereby oscillating the molten iron.
(3)
A method for supplying power to a molten iron cart according to (1) or (2) above, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body at regular time intervals in a first direction with respect to the main shaft and in a second direction opposite to the first direction.

According to the present invention, it is possible to provide a method for supplying power to a molten iron cart that is cost-effective and capable of supplying power to drive the furnace tilting device when the cart is stopped in an emergency.

This is a schematic diagram showing the external appearance of a mixed iron cart. This diagram illustrates the circuit configuration when connected to a commercial power supply. This diagram illustrates the circuit configuration when power is supplied from an electric vehicle.

The embodiments of the present invention will be described below with reference to the drawings. First, the mixed iron cart to which power is supplied in this embodiment will be described.

Figure 1 is a schematic diagram showing the external appearance of a molten iron mixing truck. As shown in Figure 1, the molten iron mixing truck 10 is equipped with a furnace body 11, a trolley 12, and a tilting device 13. It receives molten iron tapped from the blast furnace into the furnace body 11 for washing and transports the molten iron to a converter or other furnace. The furnace body 11 is provided with a washing port (not shown) and has a capacity to receive and wash approximately 150 to 300 tons of molten iron. The trolley 12 is used to transport the furnace body 11 from the blast furnace to the tapping area and travels on rails.

The tilting device 13 is equipped with a tilting motor for tilting the furnace body 11, thereby tilting the furnace body 11 and discharging the molten iron from the washing port. In other words, the tilting device 13 tilts the furnace body 11 clockwise or counterclockwise relative to the main shaft connecting it to the tilting device 13 on the opposite side of the furnace body 11, so that the washing port is lower than directly above, thereby discharging the molten iron from within the furnace body 11. Furthermore, the tilting device 13 can also tilt the furnace body 11 to oscillate the molten iron by lowering the washing port to a position lower than directly above, or it can tilt the furnace body 11 clockwise and counterclockwise at regular time intervals, in order to reduce heat dissipation and slow solidification by ensuring uniform heating of the molten iron.

Furthermore, in order to drive the tilting device 13 and tilt the furnace body 11 as described above, external power is required. In this embodiment, power can be received not only via fixed equipment in a tapping area, but also via portable equipment from an electric vehicle. First, an example of receiving power via fixed equipment will be described.

Figure 2 illustrates a system for supplying power using commercial power. The tilting device 13 of the mixing iron wheel 10 is equipped with a connection plug 203. By connecting this plug to the connection connector 202 of the fixed equipment, power is supplied to the tilting device 13 from the commercial power supply (3φ, 200V).

On the other hand, the tilting device 13 is equipped with a tilting motor 204, an electromagnetic brake 205, an eddy current brake 206, and a gear grease pump 207. When power is supplied to the tilting motor 204, the electromagnetic brake 205, and the eddy current brake 206, these components are driven, thereby driving the gearbox 208.

The tilting motor 204 rotates using the supplied AC power to tilt the furnace body. The electromagnetic brake 205 releases the disc brake using the supplied DC power, disabling the furnace body rotation prevention mechanism. The eddy current brake 206 generates a force that inhibits rotation using the supplied DC power, adjusting the furnace body tilting speed. The gear grease pump 207 circulates the lubricating oil within the gearbox. The gearbox 208 reduces the rotational speed of the tilting motor to a speed matching the furnace body tilting speed.

Here, since the electromagnetic brake 205 and eddy current brake 206 are driven by direct current, the stationary equipment is equipped with an AC-DC converter 201 for DC brakes. A portion of the power from the commercial power supply 200 is converted from alternating current to direct current by the AC-DC converter 201, and this direct current power is supplied to the electromagnetic brake 205 and eddy current brake 206.

Under normal circumstances, the molten iron mixer 10 travels to the tapping area, connects the connection connector 202 of the fixed equipment at the tapping area to the connection plug of the tilting device 13, and drives the tilting device 13 when power is supplied from the commercial power supply 200, tilting the furnace body 11 and releasing the molten iron. However, in the event of a natural disaster such as an earthquake or typhoon, and if the molten iron mixer 10 becomes unable to travel due to fallen trees or other obstacles, the molten iron will remain contained in the furnace body 11 for several hours or more until it is restored and arrives at the tapping area.

Therefore, in this embodiment, in such an emergency, it is possible to remove the molten iron from an emergency ironworks before it solidifies by receiving power from a commonly available electric vehicle. Next, an example of receiving power from an electric vehicle will be described.

Figure 3 illustrates a system for supplying power using an electric vehicle. The configuration on the mixed-pig truck side is the same as in Figure 2, so a detailed explanation is omitted.

The electric vehicle 300 is, for example, an electric vehicle that conforms to the CHAdeMO standard Ver. 2.0 or higher and is capable of outputting 10 kW or more of power as the power required to drive the tilting device 13. Note that, in order to protect the on-board secondary battery, the CHAdeMO standard imposes power supply limitations on some vehicle models, and some vehicle models may not be able to supply 10 kW or more of power. The reason for requiring an output of 10 kW or more is that if the output is less than 10 kW, there will be insufficient power to tilt the furnace body containing the molten iron, making it impossible to tilt the furnace body. In this embodiment, the invention is not limited to the CHAdeMO standard; by providing connectors conforming to other standards and modifying the communication software, an electric vehicle capable of outputting 10 kW or more of power conforming to other standards may also be used. Furthermore, the electric vehicle 300 is not limited to so-called EVs (Electric Vehicles); it may also be a fuel cell vehicle or the like, as long as it is capable of supplying power to the tilting device.

Next, the portable equipment will be described. The portable equipment is mainly stored in the trunk of an electric vehicle. It connects the secondary battery of the electric vehicle 300 to a CHAdeMO standard connector 301, and further connects the connection connector 306 to the connection plug 203 on the mixing truck side. This supplies power from the electric vehicle to the tilting device 13. However, unlike commercial power, the electric vehicle 300 is a DC power source, so the combination of inverter and converter differs from the fixed equipment shown in Figure 2.

The isolated DC-DC converter 302 adjusts the voltage from the electric vehicle's secondary battery to the voltage input to the DC-AC inverter 303 for the tilting motor. The DC-AC inverter 303 for the tilting motor is an inverter that converts DC to AC to supply power to the AC-driven tilting motor 204. The DC-DC converter 304 for the DC brake supplies DC power to the electromagnetic brake 205 and the eddy current brake 206. The DC-AC inverter 305 for the gear grease pump is an inverter that converts DC to AC to supply power to the AC-driven gear grease pump 207.

In addition to the configuration shown in Figures 2 and 3 for the mixing tank side, it is also possible to supply power to other equipment on the mixing tank side. In that case, a converter or inverter will be added to the fixed or portable equipment side as needed.

Next, a simulation was conducted to investigate whether the solidification of molten iron inside the furnace could be prevented by supplying power using electric vehicles in the event of a disaster. The types of disasters considered were: a typhoon causing numerous fallen trees on the route of the torpedo truck due to strong winds, and a magnitude 6 earthquake occurring within the steelworks, resulting in the truck becoming immobile and forced to make an emergency stop due to partial building collapse. For the damage caused by fallen trees due to strong winds, the recovery time (in this case, moving to the tapping area) was assumed to be 5 hours, and for the damage caused by the earthquake, the recovery time was assumed to be 10 hours.

Furthermore, when power is supplied from commercial power, the molten iron mixer is moved to the tapping area, the tilting device is driven using the tapping area's commercial power supply, and the molten iron is discharged from the furnace. When power is supplied from an electric vehicle or a large external battery, the washing pan is transported, the tilting device is driven using power from the electric vehicle or large external battery, the washing pan is positioned using a crane, and the molten iron is discharged from the furnace. Additionally, the molten iron mixer is assumed to contain 150 tons of molten iron. The simulation results are shown in Table 1.

The example illustrates normal operation when no disaster has occurred. In this case, the tilting device was driven using the fixed power supply in the tapping area to tilt the furnace body and discharge the molten iron. The molten iron did not solidify, and 100% of the molten iron was discharged.

Example 1 is a simulation result showing that, in a situation where a molten iron truck became immobile due to fallen trees caused by strong winds, an electric vehicle (vehicle type A) capable of outputting more than 10 kW of power, used as a mobile service vehicle within the steelworks, immediately arrived. Furthermore, preparations for transporting the washing pan, setting it up near the furnace body with a crane, and supplying power from the electric vehicle to the molten iron truck using portable equipment were all completed within one hour. In this case, since the molten iron inside the furnace body had not yet solidified, the molten iron discharge rate was 100%, and there were no solidified deposits inside the furnace body.

Example 2 is a simulation result showing that, in the event of a magnitude 6 earthquake rendering a vehicle immobile, the same electric vehicle (model A) as in Example 1, located within the steelworks, immediately arrived. Furthermore, preparations for transporting the washing ladle, positioning it near the furnace body with a crane, and supplying power from the electric vehicle to the molten iron mixer using portable equipment were all completed within one hour. In this case, since the molten iron inside the furnace body had not yet solidified, the molten iron discharge rate was 100%, and there were no solidified deposits inside the furnace body.

Example 3 simulated a scenario where, in the event of a magnitude 6 earthquake rendering the vehicle immobile, the same electric vehicle (model A) as in Example 1 arrived immediately within the steelworks. However, the preparation for transporting the washing ladle and positioning it near the furnace body using a crane took more time than in Example 2, totaling 1.5 hours including preparation for supplying power to the mixing truck. In this example, while positioning the washing ladle near the furnace body with a crane, power from the electric vehicle was used to tilt the furnace body so that the receiving port was lower than directly above, and the solidification of the molten iron was delayed by oscillating within an angle that prevented molten iron leakage. As a result, 100% of the molten iron was discharged, and no solidified deposits were found inside the furnace body.

Example 4 simulated a scenario where, in the event of a magnitude 6 earthquake rendering the vehicle immobile, the same electric vehicle (model A) as in Example 1 arrived immediately within the steelworks. However, the preparation for transporting the washing pan and positioning it near the furnace body using a crane took significantly longer than in Example 3, totaling two hours including preparation for supplying power to the mixing truck. In this example, while positioning the washing pan near the furnace body with a crane, power from the electric vehicle was used to tilt the furnace body clockwise and counterclockwise at regular time intervals, delaying the solidification of the molten iron. As a result, 100% of the molten iron was discharged, and no solidified deposits were found inside the furnace body.

Comparative Example 1 presents the simulation results of a scenario where a large external battery was prepared from outside the steelworks in a situation where a molten iron truck became immobile due to fallen trees caused by strong winds. In this example, the transportation and connection of the large external battery took a considerable amount of time, totaling three hours including the transportation of the washing pan and preparation for positioning it near the furnace body using a crane. Because so much time was required to supply power to the molten iron truck, it was not possible to tilt the furnace body to delay the solidification of the molten iron. As a result, 50% of the molten iron inside the furnace body solidified during the discharge, and the amount of molten iron discharged was 50%.

Comparative Example 2 presents the simulation results of a situation where a molten iron truck became immobile due to fallen trees caused by strong winds, and waited until it could be restored. In this example, it took 5 hours for the molten iron truck to become operational again. After restoration, when the molten iron was discharged at the tapping plant, 70% of the molten iron in the furnace solidified, and 30% of the molten iron was discharged.

Comparative Example 3 presents the results of a simulation in which, when a molten iron truck became immobilized due to fallen trees caused by strong winds, an electric vehicle (vehicle type B) capable of outputting less than 10 kW of power arrived immediately. Furthermore, preparations for transporting the washing ladle, positioning it near the furnace body with a crane, and supplying power from the electric vehicle to the molten iron truck using portable equipment were all completed within one hour. However, due to insufficient power output, the tilting device could not be driven, requiring a five-hour wait until power was restored and the molten iron truck became drivable again. As a result, when molten iron was discharged at the tapping area after restoration, 70% of the molten iron in the furnace body had solidified, and the discharge volume was 30%.

Comparative Example 4 shows the simulation results of a situation where a vehicle became immobile due to an earthquake of magnitude 6 and waited until it was restored. In this example, it took 10 hours for the molten iron truck to become operational again. After restoration, an attempt was made to discharge molten iron at the tapping plant, but 100% of the molten iron inside the furnace had solidified and could not be discharged as molten iron.

As described above, according to this embodiment, even if the molten iron mixing truck stops in an emergency, power can be supplied from an electric vehicle used as a mobile service vehicle within the steelworks. Therefore, the tilting device can be quickly driven to discharge the molten iron from the furnace before it solidifies. This prevents the molten iron from solidifying inside the furnace, even in the event of a disaster, and easily prevents the molten iron mixing truck from becoming unusable.

(Other embodiments)
This embodiment includes the following methods.

(Method 1)
A method for supplying power to a molten iron mixing vehicle having a furnace body that receives molten iron through a receiving port and a tilting device for tilting the furnace body, characterized in that an electric vehicle capable of outputting the power necessary to drive the tilting device is brought close to the molten iron mixing vehicle, power is supplied to the molten iron mixing vehicle from a secondary battery mounted on the electric vehicle, and the furnace body is tilted to discharge the molten iron.

(Method 2)
A method for supplying power to a molten iron cart according to Method 1, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body so that the receiving port is in a position lower than directly above, thereby oscillating the molten iron.

(Method 3)
A method for supplying power to a molten iron cart according to method 1 or 2, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body at regular time intervals in a first direction with respect to the main shaft and in a second direction opposite to the first direction.

10 Mixing iron cart 11 Furnace body 12 Cart 13 Tilting device 200 Commercial power supply 201 AC-DC converters for DC brakes 202, 306 Connection connector 203 Connection plug 204 Tilting motor 205 Electromagnetic brake 206 Vortex brake 207 Gear grease pump 208 Gearbox 300 Electric vehicle 301 Connector 302 Isolated DC-DC converter 303 DC-AC inverter for tilting motor 304 DC-DC converter for DC brake 305 DC-AC inverter for gear grease pump

Claims (3)

A method for supplying power to a molten iron cart, comprising a furnace body that receives molten iron through a receiving port, and a tilting device for tilting the furnace body,
The tilting device is,
The system includes a tilting motor for tilting the furnace body, an electromagnetic brake and an eddy current brake for controlling the rotation of the furnace body, and a gear grease pump for circulating lubricating oil in a gearbox that controls the rotational speed of the tilting motor.
An electric vehicle capable of outputting the power necessary to drive the tilting device is brought close to the iron mixing vehicle, and the voltage from the secondary battery mounted on the electric vehicle is adjusted using a first DC-DC converter to a voltage to be input to the first DC-AC inverter.
A method for supplying power to a molten iron cart, characterized by adjusting the voltage, then using the first DC-AC inverter to convert from direct current to alternating current and supply power to the tilting motor, using the second DC-DC converter to supply direct current power to the electromagnetic brake and the eddy current brake, using the second DC-AC inverter to convert from direct current to alternating current and supply power to the gear grease pump , and tilting the furnace body to discharge the molten iron. The method for supplying power to a molten iron cart according to claim 1, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body so that the receiving port is lower than directly above, thereby oscillating the molten iron. A method for supplying power to a molten iron cart according to claim 1 or 2, characterized in that, before discharging the molten iron, the tilting device is driven to tilt the furnace body in a first direction relative to the main shaft and in a second direction opposite to the first direction at regular time intervals.