JP4957515B2 - Coarse bar heating device - Google Patents

Description

  The present invention relates to a coarse bar heating apparatus that induction heats the entire area in the width direction of a coarse bar that is conveyed after completion of rough rolling.

As is well known, a hot-rolled steel sheet is manufactured by performing hot finish rolling after continuously heating a rough bar conveyed after completion of hot rough rolling by a coarse bar heating device.
FIG. 3 is a longitudinal sectional view of an example of the coarse bar heating apparatus 1. The rough bar heating device 1 is arranged symmetrically above and below the rough bar 5 that is transported after finishing the rough rolling. Illustrations and explanations thereof are omitted for those arranged in FIG.

As shown in FIG. 1, the coarse bar heating apparatus 1 includes an inductor 13 and a shield cover 12.
The inductor 13 has a substantially box-shaped outer shape having a bottom surface and a vertical surface that is substantially orthogonal to the conveying direction of the coarse bar 5, and is disposed close to the coarse bar 5 above the coarse bar 5. Thus, the substantially whole area in the width direction of the coarse bar 5 is induction heated. The inductor 13 contains a coil package 4 in which the heating coil 3 for heating the coarse bar 5 and the iron core 2 are incorporated. The bottom surface of the inductor 13 is constituted by a heat-resistant and heat-insulating plate 7 made of a refractory castable cement that incorporates a meandering water-cooled pipe 6 and insulates radiation from the coarse bar 5 to the heating coil 3. The heat-resistant and heat-insulating plate 7 is supported by appropriate means on the bottom of the coil package 4, and the coil package 4 is supported by a stud bolt 10 fixed to the fixed base 9. An insulating plate 11 is provided between the coil package 4 and the heat-resistant heat insulating plate 7.

  The distance in the vertical direction of the coarse bar heating device 1 disposed above and below the coarse bar 5 is set narrow in order to increase the heating efficiency of the coarse bar 5. For this reason, in order to prevent damage to the heat-resistant and heat-insulating plate 7 that forms the bottom surface of the inductor 13 due to warping or jumping of the tip or tail of the coarse bar 5, non-magnetic material is used on the entry side and the exit side of the inductor 13. Each of the shield covers 12 is mounted. The shield cover 12 has a substantially L-shaped cross-sectional shape, and is mounted from the vertical surface of the inductor 13 to a part of the bottom surface as shown in FIG.

  The shield cover 12 also supports the heat resistant heat insulating plate 7 by engaging with the peripheral portion of the heat resistant heat insulating plate 7. Further, in order to prevent the oxide scale of the coarse bar 5 from entering the inside of the inductor 13 from the gap between the front end portion of the shield cover 12 and the heat-resistant heat insulating plate 7, the front end portion of the shield cover 12 is insulated against clogging. A putty (not shown) is applied.

FIG. 4 is a longitudinal sectional view showing a state in which the shield cover 12 is thermally deformed as the coarse bar heating device 1 is used.
As shown in the figure, when the tip of the shield cover 12 is thermally deformed and distorted, the shield cover 12 and the heat insulating putty applied to the tip fall, and the tip of the shield cover 12 and the heat-resistant heat insulation. A gap is formed between the plate 7 and the plate 7. When the tip of the shield cover 12 is thermally deformed in this manner, the oxide scale of the coarse bar 5 enters the inside of the inductor 13 as indicated by an arrow in this figure and damages the internal insulation.

In Patent Document 1, one end of a stud bolt is joined to a water-cooled pipe of a heat-resistant heat insulating plate, and the other end is connected to an insulating plate provided between the heat-resistant heat insulating plate and the heating coil. By connecting to the fixed base supported by the stud bolt, the heat-resistant heat insulating plate is surely prevented from falling, thereby preventing the coarse oxide bar scale from entering the inside of the inductor and damaging the heating coil 3. An invention to prevent is disclosed.
Utility Model Registration Gazette No. 2587326

  Even based on the invention disclosed in Patent Document 1, it is impossible to prevent the shield cover from being deformed due to thermal deformation due to radiant heat from the coarse bar, or collision with the tip or tail end of the coarse bar. It cannot prevent the oxide scale from entering the inside of the inductor and damaging the internal insulation.

  The present invention has a built-in coil package incorporating a heating coil and an iron core for heating a rough bar that is transported after completion of rough rolling, and the bottom surface is constituted by a heat-resistant heat insulating plate that insulates radiation from the rough bar to the heating coil. And has a substantially box-shaped outer shape having a bottom surface and a vertical surface that is substantially orthogonal to the conveying direction of the coarse bar, and is disposed in the vicinity of the coarse bar above and below the coarse bar in the width direction of the coarse bar. In a coarse bar heating device comprising an inductor for induction heating over substantially the entire region and a shield cover having a substantially L-shaped cross-section attached from a vertical surface to a part of the bottom surface, further at the corner of the shield cover And a shield cover deformation suppressing member fixed in a plurality spaced apart from each other in the width direction of the coarse bar, and the shield cover deformation suppressing member is bent into a substantially L-shape with a base member mounted on the vertical surface form And a round bar-like member that is fixed to the base member and spaced apart from each other in the width direction of the coarse bar, and that is in line contact with the bottom surface and supports the bottom surface. It is.

In the coarse bar heating apparatus according to the present invention, it is desirable that both the base plate and the round bar-shaped member are made of a nonmagnetic material.
In these coarse bar heating apparatuses according to the present invention, it is desirable to satisfy the conditions defined by the following formulas (1) to (3).

Ss ≧ a · T + b (1)
ys ≧ c / Ss (2)
yp ≦ W / (ys × yL) (3)
Where Ss is the cross-sectional area (mm ² ) of the round bar-like member, T is the maximum temperature (° C.) of the coarse bar, ys is the number of round bar-like members per base member, and yp is the base W is the number of installed members, W is the frontage width (the length in the direction parallel to the width direction of the coarse bar in the region where the coarse bar inside the inductor passes, mm), and yL is the mounting pitch of the round bar-like member (Mm), a is the influence coefficient (mm ² / ° C.) of the ambient temperature affecting the thermal deformation of the round bar-like member, b is the minimum cross-sectional area (mm ² ) of the round bar-like member, c is the influence coefficient c of the number of round bars and the cross-sectional area required for supporting the heat-resistant heat insulating plate and preventing falling (c · mm ² ).

  According to the present invention, it is possible to prevent the shield cover from being deformed due to the use of the coarse bar heating apparatus, and further, scale intrusion to the inside of the inductor due to this deformation over a long period of time. For this reason, according to this invention, the lifetime of the inductor of a rough bar heating apparatus can be improved.

Hereinafter, the best mode for carrying out the rough bar heating apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1A is a longitudinal sectional view showing the coarse bar heating device 20 in the present embodiment, FIG. 1B is a view taken along arrow A in FIG. 1A, and FIG. These are perspective views which show the shield cover deformation | transformation suppression member 21 which is a component of this rough bar heating apparatus 20. FIG. In the following description, the same constituent elements as those of the coarse bar heating apparatus 1 shown in FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

  The coarse bar heating device 20 according to the present embodiment is a heating device that includes the inductor 13 and the shield cover 12 and induction-heats the entire area of the coarse bar 5 in the width direction. Since the configurations of the inductor 13 and the shield cover 12 have been described above with reference to FIG.

Since the feature of the coarse bar heating device 20 of the present embodiment is that it includes a shield cover deformation suppressing member 21, the shield cover deformation suppressing member 21 will be described.
Since the shield cover 12 is integrally bent and formed in an L shape including the tip, the heat is easily stored with the use of the coarse bar heating device 20 and the heat dissipation is poor. Furthermore, since the upper part of the shield cover 12 is fixed to the vertical surface of the inductor 13, thermal distortion occurs when exposed to radiation from the coarsely heated bar 5 for a long time. For this reason, as shown in FIG. 4, the tip of the shield cover 12 is distorted by thermal expansion, the heat-resistant putty for clogging is dropped, and the oxide scale from the coarse bar 5 is removed from the gap formed between the bottom surface of the inductor 13 and the inductor. 13 enters and the heating coil 3 is damaged.

  Therefore, in the present embodiment, the shield cover deformation suppressing member 21 is provided in order to significantly extend the life of the inductor 13 by preventing such deformation of the tip of the shield cover 12.

  As shown in FIG. 1, a plurality of shield cover deformation suppressing members 21 are fixed to two corners of the shield cover 12 in the conveying direction of the coarse bar 5 while being spaced apart from each other in the width direction of the coarse bar 5.

  As shown in FIG. 1C, the shield cover deformation suppressing member 21 includes a plate 23 that is a base member that is fixedly attached to the vertical surface of the shield cover 12 by stud bolts 22, and a rough bar 5 on the plate 23. It is comprised by the round bar 24 which is a round bar-like member fixed mutually apart from each other toward the width direction of this (six in the example of illustration).

  The round bar 24 has a shape bent in an approximately L shape, and supports the heat-resistant and heat-insulating plate 7 by making line contact with the heat-resistant and heat-insulating plate 7 forming the bottom surface of the inductor 13. That is, the “round bar-shaped member” in the present invention means a member having a cross-sectional shape that can support the bottom surface by making line contact with the heat-resistant heat insulating plate 7 that forms the bottom surface of the inductor 13. It is not limited to the round bar used with a form.

  Both the plate 23 and the round bar 24 are preferably made of a non-magnetic material in order to reduce power loss due to induction, and the length of the portion that supports the heat-resistant and heat-insulating plate 7 on the tip side of the round bar 24 is as follows. It is desirable that the length does not cross the magnetic flux generated by the heating coil 3 and can cover the tip of the shield cover 12.

Moreover, it is desirable for the shield cover deformation suppressing member 21 to satisfy the conditions defined by the equations (1) to (3) in order to prevent the deformation of the tip portion of the shield cover 12.
Ss ≧ a · T + b (1)
ys ≧ c / Ss (2)
yp ≦ W / (ys × yL) (3)
However, in the formulas (1) to (3), Ss is the cross sectional area (mm ² ) of the round bar 24, T is the maximum temperature (° C.) of the coarse bar 5, and ys is the round per plate 23. The number of bars 24 is installed, yp is the number of installed plates 23, W is the frontage width (the length in the direction parallel to the width direction of the coarse bar 5 in the region through which the coarse bar 5 inside the inductor 13 passes. Mm), yL is the mounting pitch (mm ² ) of the round bar 24, a is the influence coefficient (mm ² / ° C.) of the ambient temperature affecting the thermal deformation of the round bar 24, and b is the minimum The required cross-sectional area (mm ² ) of the round bar 24, and c is the number of round bars 24 necessary for supporting the heat-resistant heat insulating plate 7 and preventing the fall and the cross-sectional area influence coefficient c (main · mm ² ).

  Equation (1) indicates the cross-sectional area required for the round bar 24 in relation to the operating temperature of the coarse bar 5 because the thermal deformation of the bar is linearly affected by the ambient temperature. In addition, since the number of round bars 24 required to prevent the heat-resistant insulation board 7 from falling is inversely proportional to the cross-sectional area of the round bar 24, the formula (2) indicates that the minimum number of round bars 24 per plate 23 is The number of installations is shown. Further, the expression (3) shows the maximum number of plates 23 that can be installed in a direction parallel to the width direction of the coarse bar 5 in the region through which the coarse bar 5 passes in the inductor 13. Is.

  Although the mechanism by which the deformation of the shield cover 12 is suppressed by providing the shield cover deformation suppressing member 21 is not clear, it is estimated as follows.

(A) By reducing the size of each shield cover deformation suppressing member 21, the distortion generated in the shield cover deformation suppressing member 21 when the shield cover 12 is about to be deformed can be dispersed. Since the distortion amount (deformation amount) generated in the cover deformation suppressing member 21 can be reduced, the initial support state can be easily maintained, and thus the deformation of the shield cover 12 can be prevented.

(B) Since a plurality of shield cover deformation suppressing members 21 are arranged and the shield cover 12 is pressed, even if the shield cover 12 is deformed, the support state does not collapse at once. Can be prevented.

(C) The plate 23 of the shield cover deformation suppressing member 21 is fixed to the shield cover 12, but the other end of the round bar 24 whose one end is fixed to the plate 23 is not fixed to the heat-resistant and heat-insulating plate 7 but is heat-resistant. Since the heat insulating plate 7 is supported, even if the round bar 24 is thermally expanded, the stress generated in the round bar 24 is not increased, and the initial support state can be substantially maintained, thereby preventing the shield cover 12 from being deformed.

(D) Since the round bar 24 is in line contact with the heat-resistant heat insulating plate 7, there is little heat transfer from the heat-resistant heat insulating plate 7, and it is difficult to be thermally deformed. Thereby, deformation of the shield cover 12 can be prevented.

(E) Since the plate material is a round bar 24, heat dissipation is good and thermal deformation is suppressed. For this reason, when the coarse bar 5 does not exist, it dissipates heat and hardly heats the animal.

(F) Since the round bar 24 having a small size is used, the adhesiveness with the clogging putty applied to the tip of the shield cover 12 is high, the applied clogging putty is difficult to drop, and the manufacturing cost is low. It is.

  Due to these synergistic effects, the use of the shield cover deformation suppressing member 21 can prevent the oxide scale from entering the inside of the inductor 13, thereby significantly extending the life of the coarse bar heating device. be able to.

  Moreover, since the shield cover deformation | transformation suppression member 21 used by this Embodiment has a very simple structure, it is excellent also in maintainability and is desirable as the rough bar heating apparatus 20 also from this point.

  In the past, replacement of the deformed shield cover 12 required about 3 hours of work. On the other hand, in this embodiment, it is not necessary to replace the shield cover 12, and instead, it is necessary to replace the shield cover deformation suppressing member 21. However, as described above, the shield cover deformation suppressing member 21 is small. Therefore, the replacement per piece can be performed in about 10 minutes, and the maintenance time of the coarse bar heating apparatus 20 as a whole can be greatly shortened.

  In this manner, according to the present embodiment, the deformation of the shield cover 12 accompanying the use of the coarse bar heating device 20 and further the invasion of the scale into the inductor 13 due to this deformation are prevented over a long period of time. Therefore, the life of the inductor 13 of the coarse bar heating device 20 can be improved.

The present invention will be described more specifically with reference to examples.
As an example of the present invention, a coarse bar heating apparatus 20 having the structure shown in FIG. 1 was manufactured. FIG. 2A is an explanatory view showing the shape of an example of the present invention in which eleven round bars 24 are provided in the width direction of a coarse bar on a stainless steel plate 23, and FIG. 2B is the same plate. It is explanatory drawing which shows the shape of the example of this invention which provided the six round bars 24 in 23 in the width direction of the rough bar.

  On the other hand, FIG.2 (c) is explanatory drawing which shows the shield cover deformation | transformation suppression member of a comparative example using the stainless steel board | plate material (six pieces) instead of the round bar 24 in FIG.2 (b), FIG.2 (d) is explanatory drawing which shows the shield cover deformation | transformation suppression member of a comparative example using the board | plate material (11 sheets) made from stainless steel instead of the round bar 24 in Fig.2 (a).

In the present invention example shown in either FIG. 2 (a) or FIG. 2 (b), Ss is 9πmm ² , T is 1150 ° C., ys is 6, yp is 8, W is 1870 mm, yL is set to 30 mm, a = 0.01 (mm ² / ° C.), b = 4π (mm ² ), c = 150 (lines / mm ² ), and all of the above-described expressions (1) to (3) are satisfied. I did it.

  In any of the examples of the present invention, even when the shield cover 12 is about to be distorted due to thermal deformation, the deformation of the shield cover 12 is suppressed by the round bar 24, and a gap is generated between the tip of the shield cover 12 and the heat-resistant heat insulating plate 7. As a result, the heat-resistant putty for clogging was prevented from falling, and the oxide scale could be prevented from entering the inside of the inductor 13. In addition, the example of this invention shown in FIG.2 (b) had the large deformation suppression effect of the shield cover 12, and the manufacturing cost was also low.

  On the other hand, in the comparative example shown in FIG. 2C and FIG. 2D, thermal deformation of the shield cover 12 cannot be suppressed, and a gap is generated between the tip of the shield cover and the heat-resistant heat insulating plate. I have.

Fig.1 (a) is a longitudinal cross-sectional view which shows the rough bar heating apparatus in embodiment, FIG.1 (b) is A arrow directional view in Fig.1 (a), and also FIG.1 (c) is this It is a perspective view which shows the shield cover deformation | transformation suppression member which is a component of a rough bar heating apparatus. FIG. 2A is an explanatory view showing the shape of an example of the present invention in which eleven round bars are provided in a width direction of a coarse bar on a stainless steel plate, and FIG. It is explanatory drawing which shows the shape of the example of this invention which provided the round bar of the book in the width direction of the coarse bar, FIG.2 (c) is a board | plate material made from stainless steel (instead of the round bar in FIG.2 (b)). 6) is an explanatory view showing a shield cover deformation suppressing member of a comparative example, and FIG. 2 (d) shows a stainless steel plate (11) instead of the round bar in FIG. 2 (a). It is explanatory drawing which shows the shield cover deformation | transformation suppression member of a comparative example using a sheet | seat. It is a longitudinal cross-sectional view of an example of a coarse bar heating apparatus. It is a longitudinal cross-sectional view which shows the condition where the shield cover thermally deformed with use of the coarse bar heating device.

Explanation of symbols

1, 20 Coarse bar heating device 2 Iron core 3 Heating coil 4 Coil package 5 Coarse bar 6 Water cooling pipe 7 Heat-resistant heat insulating plate 9 Fixed base 10 Stud bolt 11 Insulating plate 12 Shield cover 13 Inductor 21 Shield cover deformation suppressing member 22 Stud bolt 23 Plate 24 round bars

Claims (3)

A coil package incorporating a heating coil and an iron core for heating a rough bar that is transported after completion of rough rolling is built in, and a bottom surface is constituted by a heat-resistant heat insulating plate that insulates radiation from the rough bar to the heating coil. And a substantially box-shaped outer shape having a bottom surface and a vertical surface that is substantially perpendicular to the conveying direction of the coarse bar, and is disposed adjacent to the coarse bar above and below the coarse bar. An inductor for induction heating over substantially the entire width direction;
In the coarse bar heating device comprising a shield cover having a substantially L-shaped cross-sectional shape mounted from the vertical surface to a part of the bottom surface,
Further, a shield cover deformation suppressing member fixed to a corner portion of the shield cover and spaced apart from each other toward the width direction of the coarse bar,
The shield cover deformation suppressing member has a base member mounted on the vertical surface and a shape bent in an approximately L shape, and a plurality of the shield cover deformation suppressing members are spaced apart from each other in the width direction of the coarse bar. A coarse bar heating device comprising: a round bar-like member that is fixed and that is in line contact with the bottom surface and supports the bottom surface.   The coarse bar heating apparatus according to claim 1, wherein each of the base plate and the round bar-shaped member is made of a nonmagnetic material. The coarse bar heating apparatus according to claim 1 or 2, wherein the conditions defined by the following formulas (1) to (3) are satisfied.
Ss ≧ a · T + b (1)
ys ≧ c / Ss (2)
yp ≦ W / (ys × yL) (3)
Where Ss is the cross-sectional area (mm ² ) of the round bar-like member, T is the maximum temperature (° C.) of the coarse bar, ys is the number of round bar-like members per base member, and yp is the base W is the number of installed members, W is the frontage width (the length in the direction parallel to the width direction of the coarse bar in the region where the coarse bar inside the inductor passes, mm), and yL is the mounting pitch of the round bar-like member (Mm), a is the influence coefficient (mm ² / ° C.) of the ambient temperature affecting the thermal deformation of the round bar-like member, b is the minimum cross-sectional area (mm ² ) of the round bar-like member, c is the influence coefficient c of the number of round bars and the cross-sectional area required for supporting the heat-resistant heat insulating plate and preventing falling (c · mm ² ).

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