JP3650470B2 - Electric heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric heating device. More specifically, the present invention relates to an electric heating apparatus used when a heat treatment such as quenching and annealing is performed on a material to be heated such as a strip-shaped steel plate.
[0002]
[Prior art]
Conventionally, as an electric heating device for performing heat treatment such as quenching and annealing on a material to be heated such as a strip steel plate, the material to be continuously fed is arranged at a predetermined interval along the feeding path. There is known an energization heating device for contacting an energizing roll and applying a voltage between both energizing rolls to energize and heat a heated material.
[0003]
In the energization heating apparatus, the energization roll and the pressing roll on the heating outlet side are heated by the heated material that has become high temperature by the energization heating. At this time, the roll width of the energizing roll and the pressing roll is set to Since it is larger than the width, the contact portion near the center of the energizing roll and the pressing roll is directly and intensively heated, and the non-contacting portions near both ends of the energizing roll and the pressing roll are not heated so much. Therefore, even when the diameter of the rolls and press rolls are complete, temperature deviation occurs in the roll width direction during operation, and diameter deviation (hereinafter referred to as thermal crown) occurs at the center of the roll. To do.
[0004]
As described above, when a thermal crown is generated at the central portion of the roll of the energizing roll and the pressing roll, the material to be heated comes into contact only at the central portion of the roll, and the central portion of the roll is overheated. . As a result, the thermal crown at the central portion of the roll of the energizing roll and the pressing roll is further increased, and the central portion of the heated material is intensively reduced from the energizing roll and the pressing roll. Deterioration of the shape may occur, and sparks due to poor contact may occur between the energizing roll and presser roll and the heated material, particularly at the edge of the heated material where the gap between both becomes large. When sparks are generated in this way, sparks enter the surface of the current-carrying roll and the holding roll and the surface of the heated material. May cause transfer defects. As a result, the life of the energizing roll and the pressing roll is reduced, and the quality of the heated material is reduced.
[0005]
Therefore, in order to prevent the thermal crown of the energizing roll from being generated, an energizing soaking roll in which a heat pipe is mounted in the energizing roll has been proposed (Japanese Patent Laid-Open No. 6-10062).
[0006]
In the case of using the energizing temperature equalizing roll, it is possible to surely prevent the generation of a thermal crown on the energizing temperature equalizing roll, but a heat pipe is used for the energizing temperature equalizing roll. Therefore, it is expensive and has a disadvantage in economical efficiency.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the prior art, and prevents the generation of harmful thermal crowns in the energizing roll and the pressing roll when the heated material to be continuously fed is energized and heated, and An object of the present invention is to provide an energization heating device with improved economy by reducing the number of soaking rolls to which heat pipes are attached.
[0008]
[Means for Solving the Problems]
The present invention
First, in an energization heating apparatus for energizing and continuously heating a material to be heated that is continuously fed, an energizing roll that contacts the material to be heated in a high temperature region of the material to be heated is water-cooled. Heating device arranged in contact with an oil-cooled backup roll or an oil-cooled backup roll, and a pressing roll facing the current-carrying roll across the material to be heated is a soaking roll with a built-in heat pipe The cooling water or oil flows in from the shaft of the water-cooled or oil-cooled backup roll and flows along the outer peripheral surface of the shaft so as to discharge the cooled water or oil to the end of the shaft. Energizing heating apparatus having a liquid passage formed in a spiral shape (Hereinafter referred to as the first invention),
Secondly, in the energization heating apparatus for energizing and heating the material to be heated that is continuously fed, the pressing roll that contacts the material to be heated in the high temperature region of the material to be heated is water-cooled. Heating device arranged in contact with an oil-cooled or oil-cooled backup roll, and the current-carrying roll facing the pressing roll across the material to be heated is a soaking roll with a built-in heat pipe The cooling water or oil flows in from the shaft of the water-cooled or oil-cooled backup roll and flows along the outer peripheral surface of the shaft so as to discharge the cooled water or oil to the end of the shaft. Energizing heating apparatus having a liquid passage formed in a spiral shape (Hereinafter referred to as the second invention), and
Thirdly, in an energization heating apparatus for energizing and heating the material to be heated that is continuously fed and energizing and heating the material to be heated, an energizing roll that contacts the material to be heated in a high temperature region of the material to be heated, and An energizing heating device in which a pressing roll facing the energizing roll with the material to be heated is disposed in contact with a water-cooled or oil-cooled backup roll, respectively. The cooling water or oil flows in from the shaft of the water-cooled or oil-cooled backup roll and flows along the outer peripheral surface of the shaft so as to discharge the cooled water or oil to the end of the shaft. Energizing heating apparatus having a liquid passage formed in a spiral shape (Hereinafter referred to as the third invention)
About.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
As described above, the energization heating device of the first invention is an energization heating device for energizing and heating the heated material to be continuously fed and energizing and heating the heated material, in a high temperature region of the heated material. An energizing roll that contacts the heated material is disposed in contact with a water-cooled or oil-cooled backup roll, and a pressing roll that faces the energizing roll across the heated material incorporates a heat pipe. It has the structure of being a soaking roll.
[0010]
The first invention has one major feature in that the energizing roll that contacts the heated material in the high temperature region of the heated material is disposed in contact with the water-cooled or oil-cooled backup roll.
[0011]
In the first invention, as a current-carrying roll, a conventionally used current-carrying roll can be used as it is. Therefore, in the economic aspect generated by using a soaking roll equipped with an expensive heat pipe as a current-carrying roll. The problem is solved. As described above, in the first invention, the reason why the generation of the thermal crown is suppressed even if the conventional energizing roll is used as it is is not clear, but the thermal crown is probably attached to the energizing roll when the material to be heated is passed. Occurs, and the energizing roll presses the heated material to increase the amount of heat input from the heated material to the energizing roll, but at the same time, the energizing roll also presses the backup roll to increase the heated material. It is considered that the heat input to the energizing roll is quickly removed by the backup roll and the energizing roll corrected to a flat profile comes into contact with the material to be heated by roll rotation.
[0012]
Hereinafter, the energization heating device of the 1st invention is explained based on a drawing.
[0013]
FIG. 1 is a schematic explanatory view showing an embodiment of the electric heating apparatus of the first invention.
[0014]
In FIG. 1, current-carrying rolls 2 and 3 are arranged on the lower surface of the heated material 1. On the upper part of the current-carrying rolls 2 and 3, press rolls 4 and 5 that are opposed to the current-carrying rolls 2 and 3 with the material to be heated 1 interposed therebetween are respectively arranged. Further, the backup roll 6 is disposed in contact with the energizing roll 3.
[0015]
The heated material 1 is passed through the energizing roll 2 from the energizing roll 2 in the direction of the arrow A, and generates heat by generating Joule heat by itself when energized from the power source 7. Therefore, the energizing roll 2 is a low-temperature energizing roll and the energizing roll 3 is a high-temperature energizing roll, and the thermal crown due to energization heating does not occur much in the low-temperature energizing roll 2, but the high-temperature energizing roll 3 It will be greatly generated.
[0016]
In the first invention, since the energizing roll 3 is provided in contact with the backup roll 6, heat input from the heated material 1 to the energizing roll 3 is quickly removed by the backup roll 6. As a result, it is difficult for the passing plate portion of the heated material 1 of the energizing roll 3 to be overheated, and as a result, the generation of the thermal crown of the energizing roll 3 is suppressed.
[0017]
As the energizing roll 3, a conventionally used energizing roll can be used. Examples of the energizing roll 3 include a roll made of a material such as a general roll steel such as low alloy steel and having a diameter of about 200 to 600 mm and a roll length of about 1000 to 1800 mm.
[0018]
In addition, it is preferable from the point of suppression of generation | occurrence | production of a thermal crown that the heat input to the electricity supply roll 3 from the to-be-heated material 1 is predominantly extracted with the backup roll 6. FIG. This is because, with respect to the heat input distribution in the roll width direction from the material to be heated 1, the conventional axial water cooling method can only take a uniform heat rejection form in the roll width direction with the water cooling shaft, whereas the backup roll cooling The method is based on the heat extraction distribution corresponding to the heat input distribution. That is, in the backup roll cooling system, heat is generated as a driving force by the thermal crown generated by the heat input distribution from the material to be heated 1 and the pressing force distribution due to the thermal crown. There is an advantage that the generated portion can be automatically removed with a heat removal amount corresponding to the generated thermal crown amount. From this viewpoint, as the energizing roll 3, for example, a roll having no cooling function such as a cooling water channel for cooling the shaft, or a roll having a heat insulating property in which a heat insulating material is disposed between the shaft and the shell. It is preferable to use it.
[0019]
A water-cooled or oil-cooled backup roll is used as the backup roll 6 used in contact with the energizing roll 3.
[0020]
As the water-cooled or oil-cooled backup roll, for example, a water-cooled or oil-cooled backup roll as shown in FIG. 2 can be used.
[0021]
FIG. 2 is a schematic longitudinal sectional view in the axial direction of a water-cooled or oil-cooled backup roll. The liquid flow path 8 extends along the outer peripheral surface of the shaft 9 so that cooling water or oil flows from the central portion of the shaft 9 of the backup roll 6 and the water or oil passes through contact with the inner surface of the shell 10. The water or oil after cooling is discharged from the end of the shaft 9. When the water-cooled or oil-cooled backup roll 6 is used, generally, for example, if the heated material 1 heated to about 800 to 900 ° C. is passed through, if axial water cooling or the like is not performed, When the surface of the energizing roll 3 is heated to about 700 to 800 ° C., water or oil is introduced into the liquid passage 8 and cooled so that the surface temperature of the backup roll 6 becomes about 30 to 50 ° C. In the meantime, the surface temperature of the energizing roll 3 can be cooled to 500 ° C. or lower.
[0022]
The roll width of the backup roll 6 is equal to or greater than the width of the plate portion of the heated material 1 of the energizing roll 3 so that the heat input from the heated material 1 to the energizing roll 3 can be sufficiently removed. It is preferable that it is equal to the roll width of the energizing roll 3 in order to prevent the occurrence of unevenness in the pressure on the energizing roll 3. Note that the roll width of the backup roll 6 may be larger or smaller than the roll width of the energizing roll 3 as long as it does not adversely affect the energizing roll 3.
[0023]
When the backup roll 6 is brought into contact with the energizing roll 3, in order to sufficiently remove heat input from the heated material 1 to the energizing roll 3, the reduction of the energizing roll 3 by the backup roll 6 is 0.1 kg / It is preferably 1 mm / mm or more, especially when the reduction is too large, but the material 1 to be heated is subjected to profile change by rolling (plastic deformation) or fatigue strength at the roll contact portion. Since there is a tendency that the durability of the current-carrying roll 3 is mainly reduced due to the decrease in the thickness, it is preferably 7 kg / mm or less, especially 5 kg / mm or less.
[0024]
In the first invention, since the backup roll is not in contact with the press roll 5, a soaking roll incorporating a heat pipe is used.
[0025]
FIG. 3 is a schematic sectional view in a direction orthogonal to the axis of the temperature equalizing roll 11 used as the presser roll 5 of the first invention.
[0026]
In FIG. 3, the temperature equalizing roll 11 has a metal shell 13 with a built-in heat pipe 12, and a shaft 14 is provided at the center thereof.
[0027]
A plurality of heat pipes 12 built in the metal shell 13 are provided along the direction of the axis 14 in the metal shell 13.
[0028]
The heat pipe 12 is a sealed pipe in which a heat medium is sealed, the heat medium evaporates on the high temperature side in the sealed pipe, and the generated vapor is cooled and condensed on the low temperature side in the sealed pipe. It has a function of returning to a liquid, and the condensate returns to the high temperature side by capillary action or centrifugal force. At this time, latent heat required for evaporation is supplied to the heat medium on the high temperature side, and the heat is released on the low temperature side.
[0029]
Note that the heat medium used for the heat pipe 12 varies depending on the intended heating temperature of the material to be heated 1. Specific examples of such a heat medium include water, naphthalene, sodium and the like. The heating medium has an optimum operating temperature range, for example, up to about 300 ° C. for water, up to about 300-400 ° C. for naphthalene, and up to about 1000 ° C. for sodium.
[0030]
There is no particular limitation on the outer diameter of the heat pipe 12. Usually, the heat pipe 12 having an outer diameter of about 3 to 12 mm, especially about 5 to 8 mm can be used.
[0031]
The number of heat pipes 12 provided in the metal shell 13 varies depending on the outer diameter of the metal shell 13 and the like, and thus cannot be determined unconditionally. Usually, it can be appropriately selected within a range in which no thermal crown is generated. preferable.
[0032]
If the depth of the heat pipe 12 from the surface of the metal shell 13 is too shallow, the heat pipe 12 will be plastically deformed by the contact pressure with the material 1 to be heated, and if the depth is too deep. Unfortunately, the temperature-uniforming effect in the roll width direction is reduced and the occurrence of thermal crowns and, consequently, the occurrence of sparks with the material to be heated 1 is caused. Therefore, it is usually preferably about 5 to 30 mm. .
[0033]
Examples of the material of the metal shell 13 include steel materials for general rolls such as low alloy steel.
[0034]
The diameter of the metal shell 13 is preferably about 350 to 600 mm, for example, when the material to be heated 1 is energized and heated to a temperature of about 800 to 900 ° C.
[0035]
In the energization heating device of the first invention configured as described above, it is not necessary to use a soaking roll equipped with an expensive heat pipe as in the past as the energization roll 3, and the energization roll 3, The thermal crown generated in the energizing roll 3 can be effectively suppressed only by contacting the inexpensive water-cooled or oil-cooled backup roll 6.
[0036]
Therefore, the current heating device of the first invention does not require a temperature equalizing roll having an expensive heat pipe attached to the current supply roll 3, and is an apparatus having excellent economic value.
[0037]
As described above, the energization heating device of the second invention is an energization heating device for energizing and heating the heated material to be continuously fed and energizing and heating the heated material, in a high temperature region of the heated material. A press roll in contact with the heated material is disposed in contact with a water-cooled or oil-cooled backup roll, and an energizing roll facing the press roll across the heated material has a built-in heat pipe. It has a configuration of being a roll.
[0038]
In the second invention, there is one major feature in that the pressing roll that comes into contact with the heated material in the high temperature region of the heated material is arranged in contact with the water-cooled or oil-cooled backup roll.
[0039]
In the 2nd invention, since the press roll used conventionally can be used as it is as a press roll, in the economic side generated by using a soaking roll equipped with an expensive heat pipe for the press roll. The problem is solved. As described above, in the second invention, the reason why the generation of the thermal crown is suppressed even if the conventionally used presser roll is used as it is is not clear, but it is probably the same as in the first invention that the material to be heated is passed. A thermal crown is generated in the press roll when the plate is pressed, and the force that the press roll presses the heated material increases, increasing the amount of heat input from the heated material to the press roll. At the same time, the press roll presses the backup roll. Based on the fact that the heat input from the heated material to the pressing roll is quickly removed by the backup roll and the pressing roll corrected to a flat profile comes into contact with the heated material by roll rotation. it is conceivable that.
[0040]
The energization heating apparatus of the second invention will be described below with reference to the drawings.
[0041]
FIG. 4 is a schematic explanatory view showing one embodiment of the electric heating device of the second invention.
[0042]
In FIG. 4, current-carrying rolls 2 and 3 are arranged on the lower surface of the heated material 1. On the upper part of the current-carrying rolls 2 and 3, press rolls 4 and 5 that are opposed to the current-carrying rolls 2 and 3 with the material to be heated 1 interposed therebetween are respectively arranged. Further, the backup roll 6 is disposed in contact with the pressing roll 5.
[0043]
The heated material 1 is passed through the energizing roll 2 from the energizing roll 2 in the direction of the arrow A, and generates heat by generating Joule heat by itself when energized from the power source 7. Therefore, the energizing roll 2 is a low-temperature energizing roll and the energizing roll 3 is a high-temperature energizing roll, and the thermal crown due to energization heating does not occur much in the low-temperature energizing roll 2, but the high-temperature energizing roll 3 It will be greatly generated.
[0044]
In the second invention, since the pressing roll 5 is provided in contact with the backup roll 6, heat input from the heated material 1 to the pressing roll 5 is quickly removed by the backup roll 6. The through-plate portion of the heated material 1 of the press roll 5 is hardly overheated, and as a result, the generation of the thermal crown of the press roll 5 is suppressed.
[0045]
As the pressing roll 5, a conventionally used pressing roll can be used. The press roll 5 is made of a material such as a general roll steel such as low alloy steel, and includes a roll having a diameter of about 200 to 600 mm and a roll length of about 1000 to 1800 mm.
[0046]
In addition, it is preferable from the point of suppression of generation | occurrence | production of a thermal crown that the heat input to the press roll 5 from the to-be-heated material 1 is predominantly extracted with the backup roll 6. FIG. This is because, with respect to the heat input distribution in the roll width direction from the material to be heated 1, the conventional axial water cooling method can only take a uniform heat rejection form in the roll width direction with the water cooling shaft, whereas the backup roll cooling The method is based on the heat extraction distribution corresponding to the heat input distribution. That is, in the backup roll cooling system, heat is generated as a driving force by the thermal crown generated by the heat input distribution from the heated material 1 and the pressing force distribution caused by the thermal crown. There is an advantage that the generated portion can be automatically removed with a heat removal amount corresponding to the generated thermal crown amount. From this point of view, as the pressing roll 5, for example, a roll having no cooling function such as a cooling water channel for cooling the shaft, or a roll having a heat insulating property in which a heat insulating material is disposed between the shaft and the shell. Is preferably used.
[0047]
A water-cooled or oil-cooled backup roll is used as the backup roll 6 used in contact with the presser roll 5.
[0048]
As the water-cooled or oil-cooled backup roll, for example, a water-cooled or oil-cooled backup roll 6 as shown in FIG. 2 that can be used in the first invention can be used. When the water-cooled or oil-cooled backup roll 6 is used, generally, for example, when the heated material 1 heated to about 800 to 900 ° C. is passed through, as in the first invention, axial water cooling or the like is performed. If the surface of the pressing roll 5 is heated to about 700 to 800 ° C., water or water is passed through the liquid passage 8 so that the surface temperature of the backup roll 6 is about 30 to 50 ° C. When oil is introduced and cooled, the surface temperature of the pressing roll 5 can be cooled to 500 ° C. or lower.
[0049]
The roll width of the backup roll 6 is equal to or larger than the width of the plate portion of the heated material 1 of the press roll 5 so that the heat input from the heated material 1 to the press roll 5 can be sufficiently removed. It is preferable that it is equal to the roll width of the pressing roll 5 in order to prevent the occurrence of unevenness in the pressure on the pressing roll 5. The roll width of the backup roll 6 may be larger or smaller than the roll width of the pressing roll 5 as long as it does not adversely affect the pressing roll 5.
[0050]
When the backup roll 6 is brought into contact with the pressing roll 5, in order to sufficiently remove heat input from the heated material 1 to the pressing roll 5, the reduction of the pressing roll 5 by the backup roll 6 is 0.1 kg / It is preferably 1 mm / mm or more, especially when the reduction is too large, but the material 1 to be heated is subjected to profile change by rolling (plastic deformation) or fatigue strength at the roll contact portion. Since the durability of the presser roll 5 tends to decrease mainly due to the decrease in the thickness, it is preferably 7 kg / mm or less, especially 5 kg / mm or less.
[0051]
In the second invention, since the backup roll is not in contact with the energizing roll 3, a soaking roll incorporating a heat pipe is used.
[0052]
FIG. 5 shows an embodiment of the temperature equalizing roll 11 used as the energizing roll 3 of the second invention, and is a schematic sectional view in a direction orthogonal to the axis.
[0053]
In FIG. 5, the temperature equalizing roll 11 has a metal shell 13 in which a heat pipe 12 is built, and a shaft 14 is provided at the center thereof.
[0054]
A plurality of heat pipes 12 built in the metal shell 13 are provided along the axial direction in the metal shell 13.
[0055]
The heat pipe 12 can be the same as the heat pipe built in the holding roll 5 used in the first invention.
[0056]
The number of heat pipes 12 provided in the metal shell 13 varies depending on the outer diameter of the metal shell 13 and the like, and thus can be determined unconditionally. Usually, the heat pipe 12 can be appropriately selected within a range where no thermal crown is generated. preferable.
[0057]
If the depth of the heat pipe 12 from the surface of the metal shell 13 is too shallow, the heat pipe 12 will be plastically deformed by contact with the material to be heated 1, and if the depth is too deep. In this case, the temperature-uniforming effect in the roll width direction is reduced, and the generation of a thermal crown and hence the occurrence of sparks with the heated material 1 is caused.
[0058]
As the metal shell 13, for conducting current heating, for example, a material made of a steel material for general rolls such as low alloy steel can be suitably used.
[0059]
The diameter of the metal shell 13 is preferably about 350 to 600 mm, for example, when the material to be heated 1 is energized and heated to a temperature of about 800 to 900 ° C.
[0060]
Further, as shown in FIG. 5, a cooling water passage 15 may be provided at the center portion of the shaft 14 of the temperature equalizing roll 11 in order to cool the temperature equalizing roll 11.
[0061]
In the energization heating device of the second invention configured as described above, it is not necessary to use a soaking roll equipped with an expensive heat pipe as in the past as the press roll 5, The thermal crown generated in the presser roll 5 can be effectively suppressed only by contacting the inexpensive water-cooled or oil-cooled backup roll 6.
[0062]
Therefore, the electric heating apparatus of the second invention is an apparatus excellent in economic value because the press roll 5 does not require a soaking roll equipped with an expensive heat pipe.
[0063]
As described above, the electric heating apparatus of the third invention is an electric heating apparatus for energizing and heating the material to be heated that is continuously fed, and for heating the material to be heated. In the high temperature region of the material to be heated, An energizing roll that contacts the heated material, and a pressing roll that faces the energizing roll across the heated material are arranged in contact with a water-cooled or oil-cooled backup roll, respectively. is there.
[0064]
In the third aspect of the invention, the energizing roll and the pressing roll that are in contact with the material to be heated in the high temperature region of the material to be heated are arranged in contact with the water-cooled or oil-cooled backup roll. There is a big feature.
[0065]
In the third aspect of the invention, as the energizing roll and the pressing roll, the conventionally used energizing roll and the pressing roll can be used as they are, so the soaking roll equipped with an expensive heat pipe is used for the energizing roll and the pressing roll. This eliminates the economic problems that arise. In the third invention, since the soaking roll equipped with the heat pipe is not required, the third invention is an invention having a particularly high economic value among the first to third inventions.
[0066]
In the third invention, the reason why the generation of the thermal crown is suppressed even if the conventional energizing roll and presser roll are used as it is is not clear, but probably as in the first and second inventions, A thermal crown is generated in the energizing roll and the pressing roll when the sheet is passed, and the energizing roll and the pressing roll press the heated material to increase the amount of heat input from the heated material to the energizing roll and the pressing roll. At the same time, the force that the energizing roll and the pressing roll press the backup roll is increased, and the heat input of the energizing roll and the pressing roll from the material to be heated is quickly removed by the backup roll and corrected to a flat profile. The energizing roll and the presser roll are heated by rotating the roll. Presumably based into contact with.
[0067]
Below, the electric heating apparatus of 3rd invention is demonstrated based on drawing.
[0068]
FIG. 6 is a schematic explanatory view showing an embodiment of the electric heating device of the third invention.
[0069]
In FIG. 6, current-carrying rolls 2 and 3 are arranged on the lower surface of the heated material 1. On the upper part of the current-carrying rolls 2 and 3, press rolls 4 and 5 that are opposed to the current-carrying rolls 2 and 3 with the material to be heated 1 interposed therebetween are respectively arranged. The backup rolls 6a and 6b are disposed in contact with the energizing roll 3 and the pressing roll 5, respectively.
[0070]
The heated material 1 is passed through the energizing roll 2 from the energizing roll 2 in the direction of the arrow A, and generates heat by generating Joule heat by itself when energized from the power source 7. Therefore, the energizing roll 2 and the pressing roll 4 are on the low temperature side, and the energizing roll 3 and the pressing roll 5 are on the high temperature side, and thermal crown due to energization heating is not generated much in the energizing roll 2 and the pressing roll 4 on the low temperature side. It is greatly generated by the energizing roll 3 and the pressing roll 5 on the side.
[0071]
In the third invention, the energizing roll 3 and the pressing roll 5 are provided in contact with the backup rolls 6a and 6b, respectively, so that the heat input from the heated material 1 to the energizing roll 3 and the pressing roll 5 is respectively Since it is quickly removed by the backup rolls 6a and 6b, the through-plate portions of the heated material 1 of the energizing roll 3 and the pressing roll 5 are hardly overheated. As a result, the thermal crown of the energizing roll 3 and the pressing roll 5 Is suppressed.
[0072]
As the energizing roll 3, a conventionally used energizing roll can be used. Examples of the energizing roll 3 include the energizing roll used in the first invention.
[0073]
Further, similarly to the energizing roll 3, a conventionally used pressing roll can be used for the pressing roll 5. An example of the presser roll 5 is a presser roll used in the second invention.
[0074]
Water-cooled or oil-cooled backup rolls are used as the backup rolls 6 a and 6 b used in contact with the current-carrying roll 3 and the pressing roll 5.
[0075]
As the water-cooled or oil-cooled backup roll, a backup roll that can be used in the first and second inventions, for example, a water-cooled or oil-cooled backup roll 6 as shown in FIG. 2 can be used. When the water-cooled or oil-cooled backup roll 6 shown in FIG. 2 is used as the backup rolls 6a and 6b, it is generally heated to about 800 to 900 ° C. as in the first and second inventions. When the heated material 1 is passed through, the surface of the backup rolls 6a and 6b is heated to about 700 to 800 ° C. when the surface of the energizing roll 3 and the pressing roll 5 is heated unless axial water cooling or the like is performed. When water or oil is introduced into the liquid passage 8 and cooled so that the temperature becomes about 30 to 50 ° C., the surface temperature of the energizing roll 3 and the pressing roll 5 can be cooled to 500 ° C. or less. it can.
[0076]
When the backup rolls 6a and 6b are brought into contact with the energizing roll 3 and the pressing roll 5, respectively, the backup roll 6a is used to sufficiently remove heat input from the heated material 1 to the energizing roll 3 and the pressing roll 5. The reduction of the energizing roll 3 and the reduction of the pressing roll 5 by the backup roll 6b are each preferably 0.1 kg / mm or more, especially 1 kg / mm or more, but if the reduction is too large, Since the material 1 is subject to profile changes due to rolling (plastic deformation), and the durability of the current-carrying roll 3 and the pressing roll 5 tends to be reduced due to a decrease in fatigue strength at the roll contact portion, it is 7 kg / mm or less. In particular, it is preferably 5 kg / mm or less.
[0077]
In the energization heating apparatus of the third invention configured as described above, it is not necessary to use a soaking roll equipped with an expensive heat pipe as in the prior art as the energization roll 3 and the pressing roll 5. And the thermal crown which generate | occur | produces in the electricity supply roll 3 and the press roll 5 can be effectively suppressed only by making the press roll 5 contact the backup rolls 6a and 6b, respectively.
[0078]
Therefore, the current heating device according to the third invention does not require a soaking roll equipped with an expensive heat pipe for either the current roller 3 or the presser roll 5, so that it is particularly economical among the first to third inventions. It is a device with high target value.
[0079]
【Example】
Next, the electric heating apparatus of the present invention will be described in more detail based on examples, but the present invention is not limited to such examples.
[0080]
Example 1
An electric heating apparatus as shown in FIG. 1 was used.
[0081]
As the current-carrying rolls 2 and 3, low alloy steel rolls having a diameter of 400 mm and a width of 1300 mm were used. As the holding roll 4 on the low temperature side, a rubber roll having a diameter of 300 mm and a width of 1300 mm was used. The holding roll 5 on the high temperature side has a heat pipe (outer diameter is 6 mm) in which the medium is water at a position 6 mm deep from the surface of the nickel-chromium-molybdenum steel roll having a diameter of 350 mm and a width of 1300 mm. 100 rolls mounted at equal intervals in the width direction were used. Further, as the backup roll 6, a structure shown in FIG. 2 in which a steel shell having an outer diameter of 250 mm and an inner diameter of 200 mm and a steel shaft provided with a spiral cooling water channel (fluid passage 8) are integrated. The roll which has is used.
[0082]
Next, the cooling water is introduced into the cooling water passage in the backup roll 6 and adjusted so that the surface temperature of the backup roll 6 becomes 40 ° C. or lower during operation, and the reduction of the energizing roll 3 by the backup roll 6 is 3.0 kg / The current of the power source 7 is adjusted so that a strip steel plate having a thickness of 0.2 mm and a plate width of 1000 mm is energized and heated to 850 ° C. when passing between the energizing roll 3 and the pressing roll 5. Then, the roll temperature was stabilized at a steady state by operating for 3 hours at a plate passing speed of 30 m / min. As a result, the temperature deviation in the width direction of the energizing roll 3 (temperature difference between the central portion and the end of the roll) was about 30 ° C. In addition, the roll profile (maximum difference in the uneven part in the roll width direction) is expressed by
Roll profile = Roll diameter × Linear expansion coefficient (12 × 10 ^-6 (℃ ^-1 ))
× Temperature deviation in the width direction of the roll
Based on this, it was about 140 μm. Furthermore, the temperature deviation in the width direction of the pressing roll 5 was about 10 ° C., and the roll profile obtained in the same manner as described above was about 50 μm. Thus, in Example 1, generation | occurrence | production of the harmful thermal crown which has a bad influence on operation | movement was not recognized.
[0083]
For this reason, even if the current-carrying roll equipped with a heat pipe is not used as a current-carrying roll, a conventional current-carrying roll is used, and the current-carrying roll is brought into contact with a water-cooled or oil-cooled backup roll to remove heat. It turns out that generation | occurrence | production of the thermal crown of this electricity supply roll can fully be suppressed only by doing.
[0084]
Example 2
An electric heating apparatus as shown in FIG. 4 was used.
[0085]
As the energizing roll 2, a low alloy steel roll having a diameter of 400 mm and a width of 1300 mm was used. Further, as the energizing roll 3, a low alloy steel roll having a diameter of 400 mm and a width of 1300 mm, and a heat pipe (outer diameter of 6 mm) whose medium is water at a depth of 6 mm from the surface of the roll in the width direction, etc. 100 rolls mounted at intervals were used. A rubber roll having a diameter of 300 mm and a width of 1300 mm was used as the presser roll 4, and a honeycomb roll having a diameter of 270 mm and a width of 1300 mm (a roll having a sleeve thickness of 5 mm with enhanced cushioning properties by incorporating a corrugated plate) was used as the presser roll 5. The backup roll 6 has a structure shown in FIG. 2 in which a steel shell having an outer diameter of 250 mm and an inner diameter of 200 mm is integrated with a steel shaft provided with a spiral cooling water channel (fluid passage 8). A roll having
[0086]
Next, the cooling water is introduced into the cooling water passage in the backup roll 6 and adjusted so that the surface temperature of the backup roll 6 is 40 ° C. or lower during operation. The reduction of the pressing roll 5 by the backup roll 6 is 3.0 kg / The current of the power source 7 is adjusted so that a strip steel plate having a thickness of 0.2 mm and a plate width of 1000 mm is energized and heated to 850 ° C. when passing between the energizing roll 3 and the pressing roll 5. Then, the roll temperature was stabilized at a steady state by operating for 3 hours at a plate passing speed of 30 m / min. As a result, the temperature deviation in the width direction of the pressing roll 5 is about 30 ° C., the roll profile obtained in the same manner as in Example 1 is about 100 μm, and the temperature deviation in the width direction of the energizing roll 3 is about 10 ° C. The roll profile obtained in the same manner as described above was about 50 μm, and generation of harmful thermal crowns adversely affecting operation was not observed.
[0087]
From this, even if it does not use a soaking roll equipped with a heat pipe as a pressing roll, it uses a conventional pressing roll and only removes heat by bringing the pressing roll into contact with a water-cooled or oil-cooled backup roll. Thus, it can be seen that the generation of the thermal crown of the pressing roll can be sufficiently suppressed.
[0088]
Example 3
An electric heating apparatus as shown in FIG. 6 was used.
[0089]
As the current-carrying rolls 2 and 3, low alloy steel rolls having a diameter of 400 mm and a width of 1300 mm were used. A rubber roll having a diameter of 300 mm and a width of 1300 mm was used as the presser roll 4, and a honeycomb roll having a diameter of 270 mm and a width of 1300 mm (a roll having a sleeve thickness of 5 mm with enhanced cushioning properties by incorporating a corrugated plate) was used as the presser roll 5. Further, as the backup rolls 6a and 6b, the structure shown in FIG. 2 is formed by integrating a steel shell having an outer diameter of 250 mm and an inner diameter of 200 mm and a shaft provided with a spiral cooling water channel (fluid passage 8). The roll which has is used.
[0090]
Next, cooling water is introduced into the cooling water passages in the backup rolls 6a and 6b, and the surface temperature of the backup rolls 6a and 6b is adjusted to 40 ° C. or lower during operation. While adjusting the pressure reduction of the press roll 5 to 3.0 kg / mm, when the strip steel plate having a thickness of 0.2 mm and a plate width of 1000 mm passes between the energizing roll 3 and the press roll 5, the current is heated to 850 ° C. As described above, the current of the power source 7 was adjusted and operated for 3 hours at a plate passing speed of 30 m / min to stabilize the roll temperature in a steady state. As a result, the temperature deviation in the width direction of the energizing roll 3 was about 30 ° C., the roll profile obtained in the same manner as in Example 1 was about 140 μm, and the temperature deviation in the width direction of the pressing roll 5 was about 30 ° C. The roll profile obtained in the same manner as described above was about 100 μm, and no harmful thermal crown was observed in any roll, which adversely affects operation.
[0091]
From this, even if it does not use the temperature equalization roll with which the heat pipe was mounted | worn with an electricity supply roll and a pressing roll, the conventional electricity supply roll and a pressure roll are used, and these electricity supply roll and a pressure roll are each water-cooled or oil-cooled. It can be seen that the generation of the thermal crown of the energizing roll and the pressing roll can be sufficiently suppressed by simply removing the heat by bringing it into contact with the backup roll.
[0092]
【The invention's effect】
The energization heating apparatus of the present invention can prevent the generation of harmful thermal crowns on the energizing roll and the pressing roll when the heated material to be continuously fed is energized and heated. Since it is possible to reduce the number of soaking rolls equipped with heat pipes that are used to prevent the occurrence of this, it is excellent in economic efficiency.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing an embodiment of an electric heating apparatus of the present invention.
FIG. 2 is a schematic longitudinal sectional view in the axial direction of a water-cooled or oil-cooled backup roll used in the electric heating apparatus of the present invention.
FIG. 3 is a schematic cross-sectional view in a direction orthogonal to the axis of a soaking roll used as a pressing roll used in the electric heating apparatus of the present invention.
FIG. 4 is a schematic explanatory view showing an embodiment of the electric heating apparatus of the present invention.
FIG. 5 is a schematic cross-sectional view in a direction perpendicular to the axis of a soaking roll used as an energizing roll used in the energizing heating apparatus of the present invention.
FIG. 6 is a schematic explanatory view showing an embodiment of the electric heating apparatus of the present invention.
[Explanation of symbols]
1 Heated material
3 Energizing roll
5 Pressing roll
6 Backup roll
6a Backup roll
6b Backup roll
12 Heat pipe

Claims (3)

In an energization heating apparatus for energizing and heating the material to be heated that is continuously fed, the energizing roll that contacts the material to be heated in a high temperature region of the material to be heated is water-cooled or oil-cooled. An electric heating device that is disposed in contact with a backup roll, and a pressing roll facing the electric roll across the material to be heated is a temperature equalizing roll with a built-in heat pipe , the water-cooled type or the oil Cooling water or oil flows in from the shaft of the cold backup roll, and a liquid passage spirally provided along the outer peripheral surface of the shaft so as to discharge the cooled water or oil to the end of the shaft An energizing heating device . In an energization heating apparatus for energizing and heating the material to be heated that is continuously fed, the pressing roll that contacts the material to be heated in a high temperature region of the material to be heated is water-cooled or oil-cooled. An energizing heating device that is disposed in contact with a backup roll, and the energizing roll that faces the presser roll across the material to be heated is a temperature equalizing roll with a built-in heat pipe , the water cooling type or the oil Cooling water or oil flows in from the shaft of the cold backup roll, and a liquid passage spirally provided along the outer peripheral surface of the shaft so as to discharge the cooled water or oil to the end of the shaft An energizing heating device . In an energization heating apparatus for energizing and heating a material to be heated that is continuously fed and energizing and heating the material to be heated, an energizing roll that contacts the material to be heated in a high temperature region of the material to be heated, and the material to be heated An energizing heating device in which a pressing roll facing the energizing roll is in contact with a water-cooled or oil-cooled backup roll, respectively, and is cooled from the shaft of the water-cooled or oil-cooled backup roll. An energization heating apparatus having a fluid passage formed in a spiral shape along the outer peripheral surface of the shaft so that water or oil for use is introduced and the cooled water or oil is discharged to the end of the shaft .

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