Patent Application
20200017928
The present invention relates to a heating device and a heating method heating an inside of a torpedo car.
In a steel plant, molten iron produced in a shaft furnace is conveyed to a steelmaking factory by a torpedo car, and preliminary treatment of the molten iron such as desiliconization treatment is performed in the torpedo car during conveyance. An inner wall of the torpedo car is formed by a refractory so as to accommodate the high-temperature molten iron. When the refractory is damaged due to repeated operations of the torpedo car treating the high-temperature molten iron, the refractory is re-installed. After that, drying of the new refractory and preheating of an inside of the torpedo car are performed so as to accommodate the high-temperature molten iron again in the torpedo car where the new refractory is installed, or when the once cooled torpedo car is used again, the torpedo car is previously heat-increased and heat-retained with a burner or the like to protect the refractory.
Conventionally, when the inside of the torpedo car is dried and preheated, the burner is inserted into the torpedo car from a mouth to supply flame and combustion gas to heat the inside of the torpedo car. When the inside of the torpedo car is dried, it is necessary to heat gradually over time so as to avoid an explosion of the refractory. Meanwhile, when the torpedo car is preheated, rapid heating is required so that the molten iron can be received promptly. A COG (coke-oven gas) amount and an air content are adjusted at the drying time and the preheating time to obtain a constant air ratio in accordance with the COG amount. At this time, exhaust gas is discharged from the mouth of the torpedo car, but the mouth is opened so as to take in and out the burner, resulting in heat loss due to the air entering from the mouth, and efficiency of the burner is lowered. Further, there is a problem that the temperature at the inside of the torpedo car largely varies due to the entering of the air.
Conventionally, a lid to retain the heat has been used after the receiving of the molten iron and when the car is empty as the lid of the mouth of the torpedo car, but the lid in that case is for sealing the mouth and does not have a discharge port of the exhaust gas. Accordingly, the lid cannot be used at the drying time and the preheating time using the burner.
Patent Document 1 discloses a heating device for a torpedo car capable of heating an inside atmosphere without inserting a burner into an inside of the torpedo car at a preheating time and a drying time of the torpedo car.
Patent Document 2 discloses a method where a burner is inserted into an inside of a torpedo car at a drying time of the torpedo car, and a shielding plate is attached by opening an upper part of a mouth for approximately 10 mm.
Patent Document 1: Japanese Patent Publication No. 4658231
Patent Document 2: Japanese Laid-open Patent Publication No. H8-27510
However, the heating device disclosed in Patent Document 1 uses a regenerative burner, and its facility cost is high. In addition, the heating device has a structure in which a lid member to enable air-tight sealing is used for a pig iron injecting and discharging port, and exhaust gas is forcibly discharged with a blower. Meanwhile, a low-cost normal burner requires an opening part to naturally discharge exhaust gas, and the above-stated regenerative burner having the air-tight structure cannot be applied thereto.
In the method disclosed in Patent Document 2, a whole of the mouth is covered with the shielding plate when the mouth is seen from the front. In such a case, exhaust gas discharged from the upper part of the mouth is discharged while being in contact with a rear surface of the shielding plate, resulting in frequent contacts between the high-temperature exhaust gas and the shielding plate to cause thermal deformation or the like of the shielding plate due to large effect of the heat load.
The present invention is made in consideration of the aforementioned points, and an object thereof is to provide a heating device and a heating method capable of performing highly-efficient and uniform heating by discharging exhaust gas while suppressing entering of the outside air when drying, preheating, and so on of an inside of a torpedo car is carried out by using a low-cost burner other than a regenerative burner.
In order to solve the above-stated problems, the present invention is characterized in that a heating device of a torpedo car which heats an inside of the torpedo car under a state where a torpedo car main body is turned in such a manner that a mouth is located at a lateral side of the torpedo car main body, the heating device comprising: a burner which is inserted into the inside of the torpedo car from the mouth; and a lid which partially covers a lower side of the mouth so that an opening of the mouth has an open area ratio set in advance in a side view.
The open area ratio is preferably 10% to 80% of an area where a cross-sectional area of the burner is excluded from an opening area of the mouth.
The lid is preferably supported by an elastic body having elasticity in a horizontal direction toward the mouth.
A refractory having elasticity may be attached to a surface of the lid on the mouth side at a part where the lid and the torpedo car are in contact.
An attachment angle of the lid with respect to a vertical direction is preferably variable.
The lid may be constituted to include an upper lid and a lower lid, where the lower lid partially covers a lower side of the mouth, and the upper lid is formed to be able to turn around a boundary with the lower lid.
The present invention according to another aspect is a heating method of a torpedo car which heats an inside of the torpedo car, comprising: turning a torpedo car main body in such a manner that a mouth is located at a lateral side of the torpedo car main body; covering a lower side of the mouth with a lid so that an opening of the mouth has an open area ratio set in advance in a side view; and heating the inside of the torpedo car by inserting a burner from the mouth.
The open area ratio is preferably set in accordance with a flow rate of gas discharged from the torpedo car when the inside of the torpedo car is heated.
According to the present invention, heating by using a burner can be efficiently performed and uniform temperature distribution in a torpedo car can be obtained because entering of the outside air is prevented and exhaust gas can be discharged by providing a lid at a lower part of a mouth. Accordingly, reduction in fuel and shortening of time for heating of the torpedo car are enabled, and cost reduction and high-efficient operation are enabled.
Since a lower side of the mouth in a side view is partially covered with a lid, in other words, an upper side of the mouth is opened, a heat load due to contact between high-temperature exhaust gas which is discharged from the upper part of the mouth and the lid is reduced, and thermal deformation or the like of the lid can be suppressed.
Hereinafter, embodiments of the present invention are explained with reference to the drawings. Incidentally, redundant description is avoided as for elements each having substantially the same functional constitution by supplying the same reference numerals in the present specification and the drawings.
The heating device 1 includes a burner 2 and a lid 4 which is fixed to the burner 2 through an intermediary of a support bracket 3. Various burners except a regenerative burner can be used as the burner 2, and for example, as illustrated in
The lid 4 shuts off a part of the mouth 13 in a side view when the mouth 13 is seen from the front in order to obtain an open area ratio in accordance with a state at the heating time with respect to an opening area of the mouth 13. When the open area ratio in the side view is too small, discharge cannot be fully performed and an exhaust gas flow velocity from the opening part increases due to increase in an internal pressure, resulting in an increase in a facility load, and a predetermined fuel from the burner 2 does not flow to cause a shortage of combustion. When the open area ratio is too large, heating efficiency decreases and temperature becomes nonuniform due to entering of the outside air. An optimal value may be set as the open area ratio in accordance with a volume capacity of the torpedo car 10, the opening area of the mouth 13, specifications of the burner 2, heating conditions, and the like, but it is preferable to set the optimal value in accordance with particularly a gas flow rate which is discharged from the torpedo car 10 when the inside of the torpedo car 10 is heated. For example, in this embodiment, the open area ratio is set to be 10% to 80% of an opening area where a cross-sectional area of the burner 2 is excluded from the opening area of the mouth 13. In this embodiment, entering of the outside air is prevented and the opening area to discharge the exhaust gas is simultaneously secured by decreasing the opening area of the mouth 13 with the lid 4.
The lid 4 is attached to cover a lower side of the mouth 13 which faces approximately the vertical direction. When the lid 4 is disposed at an upper part of the mouth 13, exhaust gas is discharged while being in contact with a rear surface of the lid 4 resulting in frequent contacts between the high-temperature exhaust gas and the lid 4 to cause thermal deformation or the like of the lid 4 due to large effect of the heat load. Meanwhile, the lower side is less affected by the exhaust gas. In this embodiment, a shape of the lid 4 is a half-moon shape where a part of a center part of the mouth 13 where the burner 2 is inserted is cut-off from approximately a semicircle as illustrated in
As illustrated in
A window 21 to visually check the inside of the torpedo car 10 may be provided at the lid 4. Further, a flame-shielding plate 22 may be provided around the upper part of the mouth 13 with a proper distance from the mouth 13 as illustrated in
A using method of the above-stated heating device 1 is explained.
After the refractory 12 of the inside of the torpedo car 10 is re-installed, the torpedo car main body 11 is turned in such a manner that the mouth 13 formed at the center of the torpedo car main body 11 is located at the lateral side of the torpedo car main body 11 and the mouth 13 faces approximately the vertical direction. The heating device 1 is disposed to oppose to the mouth 13, the burner 2 and the lid 4 are slid toward the mouth 13 by moving the cart 5, and the burner 2 is inserted into the inside of the torpedo car 10 from the mouth 13. At this time, the lid 4 is pushed on the mouth 13 side by the spring 6, and the refractory 8 having elasticity which is attached to the rear surface of the lid 4 is brought into contact with the peripheral part 14 of the mouth 13, and thereby, the lid 4 is attached without any gap while corresponding to the projections and recessions of the peripheral part 14.
After that, the refractory 12 installed on the inner wall surface over both end parts in a length direction of the torpedo car main body 11 is dried and preheated with the burner 2 from the center part where the mouth 13 is formed, and thereby, the exhaust gas is discharged from the opening at the upper side while suppressing entering of the outside air with the lid 4 at the lower part.
As mentioned above, according to this embodiment, the lid 4 which secures an exit of the exhaust gas while suppressing the entering of the outside air is provided at the heating time of the inside of the torpedo car 10, resulting in that highly-efficient and uniform heating is enabled. It is possible to reduce fuel, shorten a preheating time, and reduce cost owing to the increase in heating efficiency.
In the above-stated embodiment, an upper-end part and a lower-end part of the lid 4 are preferably respectively fixed with, for example, turnable pins 31, 32 as illustrated in
The open area ratio of the mouth 13 is desirably made adjustable in accordance with a heating state because amounts of exhaust gas or the like are different between, for example, the drying time and the preheating time after the refractory 12 of the torpedo car 10 is maintained. For example, the open area ratio is preferably set to 10% to 50% at the drying time because a flow rate of combustion gas (COG amount) is small and a flow rate of the exhaust gas is small. Meanwhile, the open area ratio is preferably set to 30% to 80% at the preheating time because the flow rate of the exhaust gas is large.
As an adjustment method of the open area ratio, for example, as illustrated in
The adjustment method of the open area ratio is not limited to the above-stated method. For example, a position of an upper end of the lid 4 is set to be movable in the front-rear direction to make the attachment angle of the lid 4 with respect to the mouth 13 variable, and the opening degree may be adjusted by moving the upper end of the lid 4 toward a rear side when the open area ratio is made to be increased.
Here, according to the method disclosed in Patent Document 2, the shielding plate is attached to the mouth by opening the upper part for approximately 10 mm, but this 10 mm is uniform and the shielding plate is fixed. That is, Patent Document 2 does not disclose or suggest to adjust the open area ratio of the mouth 13 like this embodiment. Meanwhile, flexibility of the heating device 1 can be remarkably improved by making the open area ratio of the mouth 13 adjustable like this embodiment.
Though a preferred embodiment of the present invention has been explained hereinabove, the present invention is not limited to such examples. It should be understood that various changes and modifications are readily apparent to those skilled in the art within the scope of the spirit as set forth in claims, and those should also be covered by the technical scope of the present invention.
The lid 4 as illustrated in
In each of Example of the present invention and Comparative Example, a volume capacity of the torpedo car 10 was 60 m3 (molten iron: 300 ton), an opening area of the mouth 13 was 1.17 m2, a cross-sectional area of the burner 2 was 0.23 m2. A size of the lid 4 was changed to each of 0.75 m2, 0.47 m2, and 0.19 m2 to change the open area ratio of the mouth 13 covered with the lid 4 except the burner 2 to 80%, 50%, and 20%.
In each of Example of the present invention and Comparative Example, as illustrated in
It could be verified that the temperature in the torpedo car was uniformly increased in Example of the present invention compared to Comparative Example in each of the cases when the open area ratios were 20% to 80%. The oxygen concentration of Example of the present invention was lower than Comparative Example, and it could be verified that entering of the air could be suppressed. Regarding a total COG amount, energy saving of about 15% could be attained. Meanwhile, when the open area ratio was further decreased to 10%, an exhaust gas flow velocity from the opening part was increased and the facility load was increased due to the increase in the internal pressure. Further, the continuous measurement was impossible due to fuel shortage because a predetermined fuel does not flow from the burner 2.
The present invention can be applied as a heating device when an inside of a torpedo car is heated with a burner and is useful when heating is performed by using a burner other than a regenerative burner.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-074219 | Apr 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/012479 | 3/27/2018 | WO | 00 |
