JP5038386B2 - Catenary furnace - Google Patents

Description

  The present invention relates to a catenary furnace for continuously heat treating a strip material.

  In a catenary furnace that continuously heats the strip material, it is necessary to support the strip material in the furnace. For this reason, it is common to place a support roller in the furnace. Although it is necessary, if the operation of the furnace is stopped and the support roller is replaced, a very long stop time is required for cooling and reheating the furnace, so that the operating rate is greatly reduced.

  Therefore, for example, as described in Patent Document 1, two support rollers are provided in the circumferential longitudinal direction of the rotary drum, and the support roller that supports the strip material is replaced by rotating the rotary drum. The technology to do is known. The rotating drum is disposed at the opening of the furnace body and exposes one support roller to the outside of the furnace body, so that the damaged support roller can be replaced with a new one without stopping the operation of the catenary furnace.

  As a problem of using such a rotary drum, there is a case where a gap between the rotary drum and the furnace body is large, resulting in poor thermal efficiency. Patent Document 2 discloses an invention in which a seal member that can seal between a furnace body and a rotating drum and is separated from the rotating drum when rotating the rotating drum is disclosed in order to increase the thermal efficiency of such a catenary furnace. Has been. However, in order to drive the seal member, a complicated drive mechanism is required.

  Another problem with the use of the rotating drum is that the rotating drum rubs and damages the strip material when the rotating drum rotates. Patent Document 3 describes an invention in which a driving mechanism for driving the rotating drum is provided so that the peripheral speed of the rotating drum is equal to the conveying speed of the strip material. However, in order to completely prevent the strip material from being damaged by the rubbing of the rotating drum, it is necessary to accelerate the peripheral speed of the rotating drum whose mass is never small to the conveying speed of the strip material instantly. Even if a high-power drive mechanism is adopted, it is difficult to accelerate the rotating drum to such an extent that the strip material can be completely prevented from being scratched and damaged.

  Therefore, Patent Document 4 describes an invention in which an auxiliary roller that rises only when the rotating drum is rotated and supports the strip material instead of the supporting roller is provided. Such an auxiliary roller normally needs to be retracted below the support roller so as not to come into contact with the strip material, and in order not to interfere with the rotating drum, it needs to be provided at a position somewhat away from the support roller. There is.

  However, if the support roller and the auxiliary roller are separated from each other, the path through which the strip material is conveyed differs depending on whether the support roller is supported by the support roller or the auxiliary roller. There is a temperature distribution in the furnace according to the arrangement of the burner and the like, and the heat treatment temperature condition slightly changes when the transport path of the strip material is changed. In recent years, the sophistication of heat treatment has progressed, and such a change in temperature condition has been regarded as a problem.

JP-B-2-33767 JP-A-10-265855 Japanese Patent Laid-Open No. 9-249920 JP-A-9-296227

  In view of the above problems, the present invention provides a catenary furnace capable of exchanging a support roller that supports a strip material without changing the temperature condition of the heat treatment of the strip material and without damaging the strip material, and It is an object of the present invention to provide a catenary furnace including a support roller replacement mechanism having a high sealing property.

  In order to solve the above problems, a catenary furnace according to the present invention includes a rotary drum provided with a plurality of support rollers that can rotate while supporting a strip material in the circumferential direction, and the rotary drum rotates when the rotary drum rotates. In a catenary furnace having a rotatable auxiliary roller for supporting the strip material instead of a support roller, and sealing the furnace body with the rotary drum, an accommodation groove for accommodating the auxiliary roller is provided in the rotary drum. Shall be.

  According to this configuration, the use of the auxiliary roller prevents the strip material from coming into contact with the rotating drum when the support roller is replaced, and the strip material is not damaged. Further, since the auxiliary roller can be accommodated in the accommodation groove provided in the rotating drum during normal operation, the position where the support roller supports the strip material and the position where the auxiliary roller supports the strip material are close to each other. . As a result, the transport path of the strip material when it is supported by the support roller and when it is supported by the auxiliary roller hardly changes, so that the distribution of the furnace temperature with respect to the strip material is maintained. As a result, even when the support roller is replaced, the distribution of the amount of heat applied to the strip material does not change, and the temperature condition of the heat treatment is kept constant.

  Further, in the catenary furnace according to the present invention, the rotating drum is stopped with the angular position between the rotating shaft of the support roller and the rotating shaft at the center of the auxiliary roller being stored in the receiving groove being directly above. May be.

  The rotary drum cannot seal the furnace body at the portion holding the support roller and the portion of the receiving groove. Usually, since the opening of the furnace body is horizontal, the opening width of the furnace body is equal before and after the rotating shaft of the rotating drum. For this reason, when the rotating drum is stopped with the support roller at the top, an opening larger than the width of the receiving groove is required before and after the support roller. Therefore, the opening width of the furnace body can be reduced by setting the space between the support roller and the auxiliary roller directly above. Also, when the auxiliary roller is accommodated near the rotation center of the rotating drum, the auxiliary roller protrudes to a position where it does not interfere with the rotation of the rotating drum when the auxiliary roller is moved relative to the rotating drum in the vertical direction. Less travel distance is required to make it happen.

The catenary furnace according to the present invention further includes a movable sealing member that can move the auxiliary roller up and down, and that can seal a shaft through groove that receives the shaft of the auxiliary roller provided on a side wall of the furnace body. May be.

  According to this configuration, by moving the auxiliary roller up and down, the auxiliary roller is retracted outside the rotation range of the rotating drum and the supporting roller in order to lift and support the strip material from the supporting roller and rotate the rotating drum. Can be made. For this purpose, a shaft through groove through which the shaft of the auxiliary roller penetrates is required on the side wall of the furnace body. During normal operation, the upper part of the shaft through groove is sealed with a sealing member to prevent a decrease in thermal efficiency. it can.

  Further, in the catenary furnace according to the present invention, the support roller is disposed inside an outer circumference circle of the rotary drum, and the rotary drum has a shape in which the vicinity of the support roller is set back inside the outer circumference circle. It may be.

  According to this structure, the radius of the space required for rotation of a rotating drum is made small by arrange | positioning a support roller inside the outer periphery circle | round | yen of a rotating drum. At the same time, the shape of the rotating drum is made such that both sides of the supporting roller are cut away from the outer circumference so that the rotating drum does not contact the strip material supported by the supporting roller. Thereby, the drive amount for ensuring the clearance for rotating a rotating drum can be made small, and a drive mechanism can be simplified.

  Further, in the catenary furnace according to the present invention, the rotating drum can be moved up and down, is lifted and pressed against the furnace body, and descends to ensure a clearance for rotation with the furnace body. Also good.

  According to this configuration, since the rotary drum is pressed against the furnace body to eliminate the gap, the furnace body is reliably sealed. Further, since a separate member for sealing the gap is unnecessary, the structure is simplified.

  In the catenary furnace of the present invention, the lower side of the furnace body where the rotary drum is pressed against may be expanded in a tapered shape.

The part of the furnace body where the rotating drum is pressed needs to have a copying shape of the rotating drum, but if it is a perfect copying shape, the space between the rotating drum and the furnace body that can be formed when the rotating drum is lowered The radial clearance for the rotation of the rotating drum becomes smaller as the furnace body is lower, that is, the angular position of the rotating drum is farther from the apex. Therefore, by expanding the lower side of the portion where the rotary drum is pressed into a tapered shape, the clearance can be increased and the elevation distance of the rotary drum can be reduced.

  According to the present invention, during the normal operation, the auxiliary groove for holding the strip material is accommodated in the accommodating groove provided in the rotating drum when the support roller is replaced. The position for supporting the strip material is close, and the heat treatment conditions are kept constant.

It is sectional drawing orthogonal to the strip material conveyance direction of the catenary furnace of 1st Embodiment of this invention. FIG. 2 is a partial cross-sectional view in the furnace in the strip material conveyance direction during normal operation of the catenary furnace of FIG. 1. It is a perspective view of the rotating drum of the catenary furnace of FIG. It is a fragmentary sectional view in the furnace of the strip material conveyance direction at the time of support roller replacement | exchange of the catenary furnace of FIG. It is the elements on larger scale of FIG. FIG. 2 is a partial cross-sectional view of the outside of the furnace body in the strip material conveyance direction during normal operation of the catenary furnace of FIG. 1. FIG. 2 is a partial cross-sectional view of the outside of the furnace body in the strip material conveyance direction when the support roller of the catenary furnace of FIG. 1 is replaced. It is a fragmentary sectional view in the furnace of the strip material conveyance direction at the time of normal operation of the catenary furnace of 2nd Embodiment of this invention. It is a fragmentary sectional view in the furnace of the strip material conveyance direction at the time of support roller replacement | exchange of the catenary furnace of FIG. It is a perspective view of the alternative of the rotating drum which concerns on this invention.

  Embodiments of the present invention will now be described with reference to the drawings. 1 and 2 show a catenary furnace 1 according to a first embodiment of the present invention. The catenary furnace 1 heats the inside of a furnace body 2 made of a heat-resistant material with a burner (not shown) and continuously heats the metal strip material 3 transported inside the furnace body 2. FIG. 1 shows a cross section orthogonal to the conveying direction of the strip material 3, and FIG. 2 shows a cross section at the center of the strip material 3.

  As shown in FIG. 2, the catenary furnace 1 has a partially raised bottom wall of the furnace body 2, and a support opening 4 that crosses the furnace body 2 and opens downward is formed in that portion. . As shown in FIG. 3, the support opening 4 is formed, for example, by casting castable ceramic into a substantially cylindrical shape, and is sealed by a rotating drum 5 that can rotate around its central axis.

  As shown in FIG. 1, two support rollers 7 for supporting the strip material 3 are rotatably held on a support member 6 provided on the shaft of the rotary drum 5. As shown in FIG. 3, each of the support rollers 7 is accommodated in a support groove 8 that extends in the longitudinal direction on the outer periphery of the rotary drum 5. As shown in FIG. 2, the support rollers 7 are disposed around the axis of the rotating drum 5 at intervals of 180 °, and are held so that the outer periphery thereof is located inside the outer peripheral circle of the rotating drum 5. .

  As shown in FIG. 2, the rotary drum 5 is scraped off so that the vicinity of the support roller 7, that is, the edge portion of the support groove 8 in the conveying direction of the strip material 3 is retracted to the inside of the outer circumferential circle of the rotary drum 5. A clearance is formed so that the rotary drum 5 does not contact the strip material 3 supported by the support roller 7.

  The catenary furnace 1 includes an auxiliary roller 9 that is disposed in the vicinity of the support roller 7 and can support the strip material instead of the support roller 7. The auxiliary roller 9 can be moved up and down by a drive mechanism (not shown) and can be rotated. When the auxiliary roller 9 is raised, the auxiliary roller 9 lifts and supports the strip material 3 from the support roller 7 as shown by a two-dot chain line in FIG. . Further, when the auxiliary roller 9 is lowered, the auxiliary roller 9 is lowered to a position lower than the support roller 7 and retracts so as not to contact the strip material 3 supported by the support roller 7. At this time, the auxiliary roller 9 is accommodated in the rotary drum 5 in one of the two accommodation grooves 10 provided so as to be adjacent to the support groove 8 as shown by a two-dot chain line in FIG. It has become.

  When the rotary drum 5 is stopped at an angular position where one of the two support rollers 7 is inclined by a predetermined small angle to the opposite side of the auxiliary roller 9 from directly above the central axis of the rotary drum 5, the receiving groove 10 is The auxiliary roller 9 can be accommodated. That is, the rotary drum 5 is stopped with the angular position between the central axis of the support roller 7 and the central axis of the auxiliary roller 9 accommodated in the accommodation groove being directly above.

  As shown in FIG. 2, the inner end surface of the support opening 4 formed by the thickness of the furnace wall is a cylindrical surface whose upper half follows the rotary drum 5 and whose lower half extends discontinuously from the upper portion. It is a plane. An elastic member 11 made of an elastic felt formed of ceramic fibers is attached to the end face of the support opening 4.

  Further, as shown in FIG. 1, the rotary drum 5 is held up and down by an elevating mechanism such as a fluid pressure cylinder 12, and is lifted and pressed against the support opening 4 to seal the support opening 4. Stop. At this time, the elastic member 11 serves as a cushioning material that seals the gap between the furnace body 2 and the rotary drum 5 and prevents damage due to an impact when the furnace body 2 and the rotary drum 5 are pressed.

  When replacing the support roller 7 in the catenary furnace 1, first, the auxiliary roller 9 is raised and the auxiliary roller 9 supports the strip material 3. Then, as shown in FIG. 4, the rotating drum 5 is lowered to separate the rotating drum 5 from the support opening 4 of the furnace body 2, thereby providing a space around the outer periphery of the rotating drum 5. In this state, by rotating the rotary drum 5 by 180 °, the support roller 7 held on the upper side of the rotary drum 5 and supporting the strip material 3 and the support roller held on the lower side of the rotary drum 5 Swap 7

  Then, the rotary drum 5 is raised again and pressed against the furnace body 2 to seal the support opening 4. When the support roller 7 moved to the upper side of the rotary drum 5 is sufficiently heated by the hot air in the furnace, the auxiliary roller 9 is lowered and received in the receiving groove 10 of the rotary drum 5, and the adjacent support roller 7. The strip material 3 is handed over. Since the support roller 7 moved to the lower side of the rotating drum 5 is held outside the furnace body 2, even if the operation of the catenary furnace 1 is continued, it is cooled by the outside air and the catenary furnace 1 is stopped. It can be exchanged for a new one without having to. That is, the support roller 7 that supports the strip material 3 can be prepared in advance.

  Since the catenary furnace 1 is provided with the accommodation groove 10 for accommodating the auxiliary roller 9 in the rotary drum 5, the support roller 7 and the auxiliary roller 9 are arranged at very close positions. For this reason, the trajectory for transporting the strip material 3 when supported by the support roller 7 and the trajectory for transporting the strip material 3 when supported by the auxiliary roller 9 hardly change. The temperature inside the furnace body 2 varies depending on the position depending on the arrangement of the burner, but the temperature condition of the heat treatment does not change because the transport path of the strip material 3 does not change even when the support roller 7 is replaced.

  Further, in the catenary furnace 1, since the outer surface of the cylindrical rotating drum 5 is pressed against the support opening 4, compared with the case of sealing by another member, the pressure contact area with respect to the peripheral length of the support opening 4, that is, the seal A large area can be taken. For this reason, the catenary furnace 1 has less leakage of high-temperature air from the support opening 4 and high thermal efficiency.

  Since the support opening 4 is opened horizontally in the catenary furnace 1, the end surfaces of the support opening 4 before and after the strip material conveying direction are sealed with respect to the rotation axis of the rotation drum 5 in order to be sealed by the rotation drum 5. It must be in a symmetrical position. In the catenary furnace 1 of the present embodiment, the rotary drum 5 rotates the support groove 8 and the accommodation groove 10 with the angular position between the center axis of the support roller 7 and the center axis of the auxiliary roller 9 directly above. Since it stops so as to be distributed to both sides of the central axis of the drum 5, the width of the support opening 4 (length in the strip material conveyance direction) is slightly smaller than the total width of the support groove 8 and the accommodation groove 10. The support opening 4 is small. Also by this, the catenary furnace 1 makes it easy to seal the support opening 4.

  Further, as shown by a two-dot chain line in FIG. 5, when the inner end face of the support opening 4 is made to follow the complete shape of the rotating drum 5, when the rotating drum 5 is lowered in the vertical direction, the lower side of the furnace body 2. The clearance in the radial direction of the rotating drum 5 between the rotating drum 5 and the clearance for rotating the rotating drum 5 is reduced. Therefore, in the catenary furnace 1, as described above, the lower side of the end face of the support opening 4 is expanded in a tapered shape, so that a sufficient clearance can be achieved even on the lower side of the furnace body 2 even if the moving distance of the rotary drum 5 is small. So that you can get

  Further, when the rotating drum 5 rotates, a sufficient gap is also required between the rotating drum 5 and the auxiliary roller 9. The catenary furnace 1 stops the rotating drum 5 with the angular position between the central axis of the support roller 7 and the central axis of the auxiliary roller 9 being directly above, so that the moving direction of the auxiliary roller 9 is The angle is close to the radial direction. Thereby, the relative movement distance with respect to the rotating drum 5 required for the auxiliary roller 9 to detach | leave from the outer periphery circle | round | yen (rotation area | region) of the rotating drum 5 can be shortened.

  Further, FIG. 6 shows a side end portion of the support opening 4 of the catenary furnace 1, that is, a side surface of the furnace body 2, and an incidental structure related to sealing of the support opening 4 will be described. The support opening 4 is a substantially semi-circular opening that follows the rotating drum 5 on the side wall of the furnace body 2, and the elastic member 11 is stretched and attached to the entire portion that contacts the rotating drum 5. Further, the side wall of the furnace body 2 is formed with a shaft through groove 13 extending upward from the copying shape of the rotating drum 5 in order to receive the shaft of the auxiliary roller 9 as shown in FIG. ing.

  A water cooling jacket 14 in which cooling water is circulated is provided outside the furnace body 2 so as to surround the shaft through groove 13. Further, a sealing member 15 made of a heat insulating material that faces the water cooling jacket 14 and moves up and down together with the auxiliary roller 9 is provided outside the water cooling jacket 14. The sealing member 15 descends together with the auxiliary roller 9 to seal the shaft through groove 13. Further, the sealing member 15 is formed with a groove 16 for receiving the rotation shaft of the support roller 7.

  Thus, in the catenary furnace 1, the shaft through groove 13 is sealed with the sealing member 15, so that the air in the furnace does not escape from around the shaft of the auxiliary roller 9. Further, since the water cooling jacket 14 is provided to cool the sealing member 15, the sealing member 15 can be formed of a material having a normal heat-resistant temperature. In the catenary furnace 1, although not shown, it is desirable that the rotary drum 5, the support roller 7, and the auxiliary roller 9 also have a known coolable structure that can be cooled by circulating cooling water.

  8 and 9 show a catenary furnace 1a according to the second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, the rotating drum 5a is formed in a substantially regular hexagonal column shape. As shown in this example, the rotating drum 5a in the present invention does not necessarily have a cylindrical shape.

  The inner end face of the support opening 4 of the catenary furnace 1a is a tapered plane whose lower side expands following the shape of the rotary drum 5a. In the present embodiment, the rotating drum 5 a is designed so that the auxiliary roller 9 can be received in the receiving groove 10 in a state where the rotating drum 5 a is stopped with the support roller 7 at the top.

  In the catenary furnace 1a, the auxiliary roller 9 cannot be raised and lowered, and the rotating drum 5a is lowered to a position where the auxiliary roller 9 does not interfere with rotation as shown in FIG. The support roller 7 moves down with the lowering of the rotary drum 5 a, thereby delivering the strip material 3 to the auxiliary roller 9. Since the support roller 7 of the catenary furnace 1a protrudes from the outer circumference of the rotary drum 5a, it is necessary to provide a clearance in consideration of the rotation of the support roller 7 when the rotary drum 5a is rotated.

  Further, the accommodation groove in the present invention does not have to be a so-called groove shape, and may be any shape as long as the outer periphery of the rotating drum is partially dug down. For example, in the rotating drum 5 b shown in FIG. 10, it is understood that the space formed by scraping the rotating drum 5 b in a plane is the receiving groove 17 integrated with the supporting groove that receives the supporting roller 7.

  In addition, the rotating drum according to the present invention can be shortened in descending distance necessary to secure a space for rotation by making the schematic shape cylindrical or regular polygonal column, but the support opening of the furnace body is sealed. Any shape may be used as long as it can be stopped.

DESCRIPTION OF SYMBOLS 1,1a ... Catenary type furnace 2 ... Furnace body 3 ... Strip material 4 ... Support opening 5, 5a, 5b ... Rotating drum 6 ... Support member 7 ... Support roller 8 ... Support groove 9 ... Auxiliary roller 10 ... Accommodating groove 11 ... Elasticity Member 12 ... Fluid pressure cylinder 13 ... Shaft through groove 14 ... Water cooling jacket 15 ... Sealing member 17 ... Housing groove

Claims (6)

A rotating drum provided with a plurality of support rollers that can rotate while supporting a strip material in the circumferential direction, and a rotatable auxiliary roller that supports the strip material instead of the support roller when the rotating drum rotates. In a catenary type furnace that seals the furnace body by the rotating drum,
A catenary furnace characterized in that an accommodating groove for accommodating the auxiliary roller is provided in the rotating drum.   2. The rotary drum is stopped by setting an angular position between a rotation shaft of the support roller and a rotation shaft at the center of the auxiliary roller when the rotation drum is stored in the storage groove to be directly above. The catenary furnace described. The auxiliary roller can be raised and lowered;
The catenary furnace according to claim 1 or 2, further comprising a movable sealing member capable of sealing a shaft through groove that receives the shaft of the auxiliary roller provided on a side wall of the furnace body.   The said support roller is arrange | positioned inside the outer periphery circle | round | yen of the said rotating drum, The said rotating drum is carrying out the shape where the vicinity of the said support roller retreated inside the said outer periphery circle | round | yen. To the catenary reactor according to any one of 3 to 4.   5. The rotary drum according to claim 1, wherein the rotary drum is movable up and down, is lifted and pressed against the furnace body, and descends to secure a clearance for rotation between the rotary drum and the furnace body. A catenary furnace according to any one of the above.   The catenary furnace according to any one of claims 1 to 5, wherein a lower side of a portion of the furnace body where the rotary drum is pressed is expanded in a tapered shape.

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