JP3414553B2 - Heating equipment for hollow steel pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to, for example,
Large diameter steel pipes such as rectangular and rectangular
The hollow steel pipe used for manufacturing
To the heating furnace and transported in the heating furnace.
A hollow steel pipe that is heated at a high temperature during transport and then unloaded from the heating furnace
Heating equipment. [0002] 2. Description of the Related Art Conventionally, there is a large
For example, see Japanese Patent Publication No. 58-13245.
It was obtained by a manufacturing method. That is, this conventional method
Transports one thick steel plate in the length direction and
After the work, press it to correspond to the four corners of the square steel pipe.
Bend to form a shape similar to a square steel pipe.
The approximate square steel pipe is passed through multiple stages of forming rolls
While forming into a tubular shape, the groove butting surfaces are sequentially tacked and melted.
And weld the inner and outer surfaces of the groove member by automatic welding
After that, a large-diameter rectangular steel pipe was obtained by removing the strain.
You. However, it is manufactured by the cold forming described above.
According to the large-diameter square steel pipe, the hardness of the corners and seam welds
Is considerably higher than the flat part (base material),
Increased yield strength at corners and seam welds, lower ductility
When performing secondary welding, etc.
Special management as it may cause cracks
Required and the mechanical properties are uneven and residual stress
Therefore, cutting and the like cannot be easily performed. In addition, the corners, seam welds and flat portions
Since the yield point does not appear in the
In the case of frequently occurring structures, the maximum yield ratio exceeds 80%
The local elongation capacity of the structure decreases,
There is a risk that the risk of breakage may increase, and
Insufficient for building construction. [0005] Furthermore, yielding occurs particularly at corners and seam welds.
Buckling strength due to tensile and compressive residual stresses close to the point
Is low, so welding, cutting
Or when performing hot-dip galvanizing, etc.
Can control cracks and cracks caused by release of residual stress
It may cause such deformation. And especially
In the corner, a large toughness strain is locally generated by bending.
Since this remains, this part becomes extremely brittle and the transition temperature is
May exceed temperature and break down at low temperatures
May be reached. Therefore, recently, there is a need for a large-diameter rectangular steel pipe.
Using a round steel pipe of a fixed diameter, plate thickness, and length
Is heated in a heating furnace, and then the heated raw tube is formed into a round steel tube.
Hot forming with a mill to obtain a purified raw tube,
Hot forming into a large-diameter rectangular steel pipe with a steel pipe forming mill
It is necessary to manufacture large-diameter rectangular steel pipes that solve the above-mentioned problems.
And are provided. [0007] However, the above round steel
In a production method using a tube as a raw tube, the heating furnace
Because the tube is heated at a high temperature, the original tube is
A conveying device for conveying, i.e., a roller conveyor roller
Rollers and roller bearings are easily damaged by high heat.
As a result, labor and time are required for maintenance and repairs.
You. For this, the roller is cooled (water-cooled or air-cooled)
However, in this case, the thermal efficiency may decrease.
In particular, it requires cooling equipment. The roller through which the cooling water medium is passed includes
Bending occurs due to the temperature difference between the part and the outside,
The load on the roller becomes uneven and the load on the bearing
It will be heavy. Rollers to be further cooled are inside the furnace
Since the temperature is lower than the temperature,
The temperature of the touching part (surface) is low, and heating is
At the same time, causing the original tube to bend.
Fear. It is an object of the present invention to provide a cooling system.
Rollers and roller bearing devices that are not adopted
Of a hollow steel pipe that can prevent
It is in providing heating equipment. [0010] Means for Solving the Problems In order to achieve the above object,
The invention conveys a hollow steel pipe in its length direction and sends it to a heating furnace.
After carrying in and heating it at high temperature during transportation in this heating furnace,
Heating equipment for hollow steel tubes carried out of a heating furnace.
A roller conveyor for transferring hollow steel pipes is installed in the furnace,
Each roller of the roller conveyor has a cylindrical roller shaft and
A hollow steel pipe supporting portion externally fitted to a roller shaft portion of
Consisting of roller bearings integrated at both ends of the shaft
AndThe roller shaft is formed of heat-resistant and wear-resistant steel,Said
The hollow steel tube support isA pair of end parts and a central part
When these are externally fitted to the roller shaft and aligned,That
When the outer surface is formed as a concave support surface in the roller axis direction
In both cases, at least the central part in the roller axis direction is
High quality heat and wear resistantSex metalFormed byThe row
The roller bearing is an outer part integrated with the end of the roller shaft.
The smaller the diameter of the inclined cylinder and the outer end of this inclined cylinder,
And a solid rod-shaped straight shaft portion.
Each supported via a bearing device,The roller bearing section
Inclined tubeA heat shield device is provided inside. [0011] According to the configuration of the present invention described above, the carrier is transferred into the heating furnace.
The inserted hollow steel pipe is supported by the rollers on the roller conveyor.
Transported in a heating furnace and heated to high temperature during the transport.
You. At that time, each roller cools (water cooling or air cooling)
The heat efficiency can be very high and cooling
Equipment may be unnecessary. The roller shaft is not cooled
And because it is cylindrical, the hollow steel pipe support, roller shaft
And the inside of the roller shaft are the same as the furnace temperature.
As a result, the hollow steel pipe and the concave support
The temperatures of the holding surface and the furnace can be the same. Further, the roller shaft portion does not perform cooling and has a cylindrical shape.
Temperature, the inside and outside are at the same temperature.
Therefore, no temperature difference occurs. In addition, the heat on the cylindrical roller shaft side
Is prevented by the heat shield device from escaping to the roller bearing side.
Can stop. Then, the hollow steel pipe in the hollow steel pipe support
TouchCenterParts are high quality heat and wear resistantSex metalBy
Due to the formation, heat damage can be reduced. [0013] DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.
I do. As shown in FIG. 9, for example, a large-diameter rectangular steel pipe is manufactured.
In doing so, a predetermined diameter and plate suitable for this large-diameter square steel pipe
Thick, long and round hollow steel pipe is delivered as the original pipe 1
Prepared on 10 Here, the original pipe 1 is connected by high-frequency welding or arc welding.
Manufactured with a seam weld 2 by welding
But this may be a seamless source tube 1.
No. The loading floor 10 is of a conveyor type and has a plurality of original tubes 1.
And support it in parallel, and transverse to the length
And transport. The original tube 1 transported to the end of the loading floor 10 is
It is carried into the heating equipment 20 and has a length
And is heated at a high temperature during the conveyance. Predetermined
The raw tube 1 heated to the temperature is carried out of the heating equipment 20,
Then, it is transferred to the welding seam position adjusting device 11. The welding seam position adjusting device 11 is
And a presser roll 13.
By rotating the original pipe 1 around the pipe axis via the
The positions of the seam welds 2 are aligned in a certain direction. This constant
When the final large-diameter rectangular steel pipe is obtained,
This is a position where the contact portion 2 always exists near the center of the flat plate portion.
You. When the seamless original tube 1 is transported,
This part of the welding seam position adjusting device 11 is passed and
When using only the seamless raw tube 1, the weld seam position
The process by the position adjustment device 11 is deleted. Raw tube 1 from welding seam position adjusting device 11
Is carried into a round steel tube forming mill 14. Here, multiple
The original tube 1 is heated in a squeezing shape through a sizing roll 15
The final large-diameter rectangular steel pipe (product) is
Purify the original tube 1 to a specified diameter so that it can be finished in a fixed size
I do. Around the round steel pipe forming mill 14,
Stand before and after, only before, only behind, stand for section steel tube forming mill 14
(E.g., in the middle), the required number of descaler devices 16
Have been killed. The descaler device 16 is used for the primary refining tube 1.
A is a jet of water with water pressure applied to A.
Removes mill scale, etc., and improves surface skin
You. In this way, the round steel pipe forming mill 14 group
The refined raw tube 1A is transported to a square steel tube forming mill 17.
Is entered. Here, a plurality of continuous rolls 18 are used.
Hot forming (forming temperature A_Three Above the transformation point)
At that time, the large-diameter rectangular steel pipe 3 immediately after hot forming is
The flat part is formed into an outwardly arcuate surface along the
I have. Next, the large-diameter rectangular steel pipe 3 hot-formed is
Received on the cooling floor 19. This cooling floor 19 is a conveyor type
And support a plurality of large rectangular steel pipes 3 in parallel,
Then, the sheet is transported in the lateral direction with respect to the length direction. This cold
The large-diameter rectangular steel pipe 3 is gradually cooled by air cooling while being transported in the burial bed 19.
Is done. By this slow cooling, the large-diameter rectangular steel pipe 3 has
It is shrunk to make the arc surface a straight surface, and the R at the corner is
And the section modulus increases. The transportation of the three groups of large-diameter rectangular steel pipes on the cooling floor 19 is as follows.
With the large large-diameter rectangular steel pipes 3 separated from each other or
Contact the large-diameter rectangular steel pipes 3
It is transported in a state where it is locked. By this, large diameter square steel pipe 3
Will be gradually cooled at the same ambient temperature.
Bending at the time of rejection can be reduced. End of cooling bed 19 reached
The large-diameter rectangular steel pipe 3 has a straightening device (not shown),
Transported to equipment, trailing edge cutting equipment, cleaning equipment, rust prevention equipment
After being processed by each, storage as a product
Is done. As described above, hot forming from a round tube to a square tube is performed.
In that case, the heating equipment 20 is a heating furnace 21,
A roller core for transporting hollow steel pipes disposed in the heating furnace 21
The conveyor 40 and the original tube 1 from the loading floor 10 are transported to the heating furnace 21.
Conveyor 80 to be loaded and the original tube 1 from the heating furnace 21
Conveyor 81, etc., for unloading
ing. The heating furnace 21 is shown in FIGS.
As described above, the divided furnace body divided into a plurality in the length direction
22 and each split furnace body 22 is a longitudinal front view
, The upper U-shaped furnace portion 22A and the upper U-shaped furnace portion 22A
A left and right side furnace parts 22B extending downward from both lower ends of A.
These arcs are convex downwards and located between the lower ends of the side furnace parts 22B.
And the lower furnace part 22C. Here the left and right sides
The lower furnace section 22B and the lower furnace section 22C are integrated,
The furnace section 22C is supported on the floor side via a base frame 23.
You. A heating furnace formed by the above-mentioned divided furnace body 22 group
At 21, both ends in the front-rear direction are connected to the end furnace walls 24, 25.
Through holes formed in these end furnace walls 24, 25
As a result, the entrance 26 on the upper side (front end side) and the lower side
An outlet 27 is formed (at the rear end). And these transports
Opening doors 28 and 29 are provided at the entrance 26 and the exit 27, respectively.
Have been. The left and right side furnace sections 22B are arranged at predetermined intervals.
The part is formed by the block body 30 and this block body 30
Can be inserted into and removed from the side furnace section 22B in the left-right direction.
Be composed. And there is no gap when inserting
It is constructed as follows. Each block body 30 has a through hole 31 formed therein.
Through these through holes 31, the roller conveyor 40 is
A roller described below is provided. At that time, the through hole 31
It is formed at two places in the front-rear direction with respect to the divided furnace bodies 22,
Based on this, multiple rollers are specified in the front-back direction
It is arranged every pitch P. The lower part of the heating furnace 21 and the roller
The lower heating burner 33 is arranged at an intermediate position between the rollers of the
Is established. That is, the side furnace part 22B group on one side of the left and right
Is mounted so that it is located between the block bodies 30 described above.
A drill hole 34 is formed, and the lower hole is
A heat burner 33 is provided. At that time, the mounting hole 34
Is set slightly lower than the axis of the through hole 31.
Have been. Then, on the other side of the heating furnace 21 and before
In a position that faces the lower heating burner 33 in a staggered manner
Is provided with an upper heating burner 35. That is, on
The through-hole is provided in the other part on the right and left sides of the furnace part 22A.
A mounting hole 36 is formed so as to be located just above
The upper heating burner 35 is provided using the mounting hole 36 of
Have been. The split furnace body 22 adjacent to the outlet 27
A vertical smoke outlet 37 is formed in the lower furnace portion 22C.
I have. The heating furnace 21 is configured by the above 22 to 37. The roller conveyor 40 is disposed in the front-rear direction.
And a plurality of rollers 41 at predetermined pitches P. Sand
Each roller 41 has a cylindrical shape as shown in FIGS.
Roller shaft 42 and a hollow externally fitted to the roller shaft 42
A steel pipe support portion 43, integrated at both ends of the roller shaft portion 42
And a roller bearing 44. The roller shaft 42 is made of, for example, stainless steel.
Formed of heat-resistant and wear-resistant steel such as
Have been. The hollow steel pipe supporting portion 43 has a pair of end portions.
43A, 43A and a central part 43B.
When the outer surface of the roller shaft 42 is
The concave support surface 46 is formed in the direction of the axis 45. Each part 43A, 43 of the hollow steel pipe supporting part 43
A and 43B are in the direction of the roller shaft 45 with respect to the roller shaft 42.
Is slidably fitted on the
In order to perform connection in the circumferential direction, the circumference of the end portions 43A, 43A
Two locations (one or more locations)
In addition, an open fitting groove 47 is formed on the inner surface side, and
Two circumferential locations (one or multiple locations) on both outer surfaces of the central
In some places), the roller shaft center 45 is
A fitting projection 48 is provided so as to be freely fitted from the direction. Note that
In the row state, the end portions 43A, 43A are opposed to the roller shaft portion 42.
And fixed by welding A. The central portion 43B is made of high quality heat-resistant
It is formed by wear material. That is, the central portion 43B is
For heat and wear resistant materials such as cobalt, nickel and chrome
Is formed. The end portions 43A, 43A are in high-color.
It is formed by a room or the like. The roller bearing 44 is, for example, a stainless steel.
Made of heat-resistant and wear-resistant steel made of stainless steel or nickel
And integrated with the end of the roller shaft 42 by welding.
The inclined cylindrical portion 44A having a smaller diameter toward the outer side, and the inclined cylindrical portion 44A
Solid welded and then welded together
A rod-shaped straight shaft portion 44B is formed.
A plurality of screw holes 49 are formed on the insertion end face side of
You. A heat shield device 50 is provided in the inclined tubular portion 44A.
Can be That is, in the straight shaft portion 44B side in the inclined tube portion 44A.
Is provided with a heat insulating material 51 made of, for example, asbestos.
This heat insulating material 51 has a disk shape, and moves from the large diameter side to the small diameter side.
A plurality of sheets are arranged in a stack by being pushed. So
Then, the outer blocking plate 52 contacts the heat insulating material 51 group from the large diameter side.
From the outer blocking plate 52 to the heat insulating material 51 group.
A plurality of fasteners 53 in the form of rods that have been inserted
This is screwed into the screw hole 49 through the
The nut body 54 screwed to the base screw part of the fixture 53
The plate 52 is fixed. Further, the inclined cylindrical portion 44A is provided on the roller shaft portion 42 side.
Inner position for dividing the space into two in the direction of the roller axis 45
A blocking plate 55 is provided, and the inner blocking plate 55 is
The nut body 56 screwed to the base screw part 53
It is fixed to the fixture 53 side. Note that the outer shielding plate 52 and the inner shielding
The cutting plate 55 is formed of an iron plate or the like. Note that the inclined cylinder
A vent hole 57 is formed in a portion such as 44A. More than
The heat shield device 50 is constituted by 51 to 57, and furthermore by 42 to 57.
A roller 41 is formed. As shown in FIG. 4, FIG. 5, and FIG.
The roller 41 is provided with a roller bearing in the through hole 31 of the side furnace portion 22B described above.
Straight through the spout 44 and projecting outward
The shaft portion 44B is connected to the base frame 23 through a pair of bearing devices 60 and 64.
Supported on the side. Here, the other straight shaft portion 44B
Is the inner ring 62 of the bearing 61 in the bearing device 60 on the other side.
Is fixed by shrink fitting, so that the straight shaft on the other side
The portion 44B is supported by the bearing device 60 on the other side so that it can only rotate.
It is. The cylindrical shaft 44B on one side has a cylindrical collar.
The collar 67 is externally fitted to the collar 67.
The inner ring 66 of the bearing 65 is fitted on the outside,
The straight shaft portion 44B on one side is automatically rotated by the bearing device 64 on one side.
And is slidably supported via a collar 67.
The sliding in the direction of the roller shaft center 45 prevents thermal expansion.
It is supposed to be stretchable. And the other straight shaft portion 44B
Is a rotary drive (motor
69), and these rotary drive units 69 are synchronized.
It is configured to be moved. As shown in FIG. 2, FIG. 4 and FIG.
A smoke exhaust device 70 connected to the mouth 37 is provided. That is,
A main flue 71 is formed in the floor on the side of the heating furnace 21,
The beginning of the road 71 is connected to the smoke outlet 37 via the first smoke pipe 72
Have been. The second flue 73 is connected to the end of the main flue 71.
The second smoke pipe 73 is connected to the lower part of the chimney 75 through the fan 74.
Connected to the unit. A damper is provided in the middle of the second smoke pipe 73.
The damper 76 is operated to operate the damper 76.
The pressure inside the heating furnace 21 is controlled to be lower than the atmospheric pressure.
You. The smoke exhaust device 70 is configured by the above 71 to 76. A heat exchanger 78 is provided in the main flue 71.
The heat exchanged with the flue gas here passes through piping group 79.
And supplied to each burner 33, 35. The carry-in conveyor 80
Is to transfer the original tube 1 from the loading floor 10 to the roller conveyor 40
And the unloading conveyor 81 is a roller conveyor 40.
These original tubes 1 are received. Where both conveyors 8
Reference numerals 0 and 81 are constituted by a roller type or the like. The operation of the heating equipment 20 will be described below.
You. From the loading floor 10 via the loading conveyor 80
Immediately before the raw tube 1 reaches the entrance 26,
The opening / closing door 28 is opened. The original tube 1 passes through the entrance 26
Into the heating furnace 21 and the roller conveyor 40
Are supported by a group of rollers 41. That is, the original tube 1
The rollers 41 are supported and conveyed through the concave support surfaces 46 of the group.
And when the end is fully loaded,
The opening / closing door 28 is closed. As described above, the original tube 1 is supported by the rollers 41.
Transported in the heating furnace 21 and heated at a high temperature during the transport.
Is done. At that time, leave a space L between the end faces of the original pipe 1
The end face may be changed due to the elongation of the raw tube 1 during heating and the difference in transport speed.
The cat can be prevented from contacting (colliding). Still
When the distance L is too long, the efficiency becomes poor.
Therefore, the distance L is controlled to be 500 mm or less. The above-mentioned heating is performed by burning the burners 33 and 35.
It is performed by heat, but at that time, the lower heating bar
After the flame from the ner 33 flows from the lower part on one side to the lower part on the other side,
It will flow to the upper part on the other side, and the lower heating burner 33
The upper heating bar is located at a position
The flame from the top 35 flowed from the upper part on the other side to the upper part on the one side.
Later, it will flow down to one side. Therefore the whole flame
Flows in a swirling shape when the heating furnace 21 is viewed from the longitudinal front,
The swirling flow is the circle of the upper furnace section 22A and the lower furnace section 22C.
Smooth without agitating the inside by the inner surface
Done. This eliminates temperature differences inside the furnace,
Temperature can be promoted, so that the heating of the original tube 1 can be uniform.
Can be performed, and the thermal efficiency can be further improved. The lower heating burner 33 and the upper heating bar
The knives 35 are positioned so that the flame does not directly hit the
By being provided, uniform heating of the original tube 1 can be promoted.
You. Furthermore, lower heating burner 33 and upper heating burner 35
Is located at a position where the flame does not directly hit the roller 41.
By this, uniform heating of the original tube 1 can be further promoted.
You. Due to these reasons, the wafer is transferred to the heating furnace 21 at room temperature.
The inserted raw tube 1 gradually moves during the transfer in the heating furnace 21.
Heated to 723 ° C to 950 ° C (A_Three Above the transformation point)
While maintaining high temperature, in the circumferential and longitudinal directions
And is heated at a uniform temperature without bending
Will be. The element heated to a predetermined temperature in this manner
The pipe 1 is passed through the carry-out port 27 by opening and closing the door 29.
Welding seam position adjustment device after unloading from heating furnace 21
11 can be carried. And the end of the original tube 1 is completely taken out
The opening / closing door 29 of the carry-out port 27 is closed. As described above, the roller conveyor 40
During the transfer of the tube 1, each roller 41 is cooled.
(Water cooling and air cooling)
And cooling equipment is no longer required. Also roller
The shaft portion 42 is hollow because it does not perform cooling and is cylindrical.
The inside of the steel pipe support portion 43, the roller shaft portion 42, and the roller shaft portion 42,
In each case, the temperature is the same as the furnace temperature,
In the same manner, the original tube 1, the concave support surface 46, and the furnace temperature are the same.
And keep the raw tube 1 at a uniform temperature in the circumferential and longitudinal directions.
It can be heated, so that high-temperature heating without bending can be performed. Further, the roller shaft 42 does not perform cooling and
Since it is cylindrical, its inside and outside are at the same temperature and
No temperature difference occurs, so the bending of the roller shaft 42
No rounding occurs around the hollow steel pipe support 43, that is, the roller 41.
A uniform load is applied in each direction,
No unreasonable load is applied to 0 and 64. The heat on the side of the cylindrical roller shaft portion 42 is
The escape to the bearing portion 44 side is performed by the heat shield device 50,
It can be blocked by the blocking plates 52, 55 and the group of heat insulating materials 51,
Promotes uniformity with the furnace temperature inside the roller shaft 42.
As well as lowering the thermal conductivity to the straight shaft 44B.
To reduce thermal damage to the bearing devices 60, 64, and
Can easily adopt non-specific bearing devices 60, 64. The hollow steel pipe supporting portion 43 of the roller 41 is formed.
The original tube 1 is brought into contact with the central portion 43B,
The central part 43B is made of high quality heat and wear resistant material
The roller 41 to reduce heat damage.
It can be used for a long time,
, Scale adhesion to rollers, roller pressure control, etc.
Can prevent product damage. The prolonged use of the concave support surface 4
6, when the hollow steel tube support 43 is damaged,
Only the minute 43B is replaced. Make this replacement
First, the block body 30 is removed, and the removal mark is used.
Then, the roller 41 is pulled out. At that time, for example, the other
The bearing device 60 is removed from the base frame 23 and one of the bearings
The roller 41 is pulled out of the device 64. Next, by removing the welding A, the temporary welding shown in FIG.
As shown by the imaginary line, one end portion 43A is removed to one side,
The central portion 43B is also removed in the same direction. Then a new
The central part 43B is fitted from one side and the end part
43A is similarly fitted outside and fixed by welding A.
Then, the roller 41 is moved in the heating furnace 21 by the operation reverse to the above.
Can be set on the side. In addition, the pair of end portions 43A are similarly formed.
May be replaced with a new one. The hot smoke generated in the heating furnace 21 is
Can be discharged. That is, the smoke is exhausted by the operation of the fan 74.
A suction force acts on the outlet 37, which causes smoke to pass through the exhaust outlet 37.
And is sucked into the first flue 72, and the main flue 71, the second flue
After flowing to 73, it was discharged to a chimney 75 via a fan 74.
It is. Due to such suction and exhaust, the inside of the heating furnace 21 becomes negative pressure,
In other words, when the pressure becomes lower than the atmospheric pressure, the original pipe 1 is not bent.
Can be prevented from occurring. Lower than atmospheric pressure
Can be controlled by adjusting the damper 76.
You. When the hot smoke flows through the main flue 71,
The air is exchanged by the exchanger 78,
Air is supplied to each burner 33, 35 through the piping group 79.
Is done. Therefore, each burner 33, 35
The combustion air is used as combustion air for efficient combustion.
You. Normally, the combustion of each burner 33, 35 requires combustion air
Fuel (gas, natural gas, gaseous fuel such as LPG, heavy oil,
Liquid fuel such as kerosene, solid fuel such as coal)
These increase combustion efficiency. In the above embodiment, the central portion 43B is made of high quality.
It is made of heat-resistant and wear-resistant material.
A, 43A is integrated with the central part 43B to provide high quality heat resistance
It may be formed of a wear material. In the above embodiment, the heat shielding device 50 is made of the heat insulating material 51,
Consists of an outer blocking plate 52, an inner blocking plate 55, etc.
However, this may be only the two blocking plates 52 and 55,
The heating material 51 alone may be used. In the above embodiment, the hollow steel pipe was used as a circular base.
Tube 1 is shown, this is a square or rectangular hollow steel tube
It may be. In the above embodiment, the heated original tube 1
Is a large-diameter rectangular steel pipe 3, which is a raw refined pipe 1A and
May be used as a product. In the above embodiment, the entire distance between the adjacent rollers 41 is
The lower heating burner 33 is installed on the
It may be arranged in a jump or a double jump. Also, in the above embodiment,
The heating furnace 21 can be disassembled in a detachable manner,
A configuration that cannot be disassembled in a deformed form may be used. In the above embodiment, the carry-in conveyor 80 and the carry-in
The outgoing conveyor 81, especially the outgoing conveyor 81, is similar to the roller 41.
It is preferable to use a suitable roller. [0055] According to the present invention having the above structure, each roller
Does not perform cooling (water cooling or air cooling),
The rate can be very high and cooling equipment can be dispensed with.
Also, make sure that the roller shaft is not cooled and is cylindrical.
The hollow steel tube support, the roller shaft, and the inside of the roller shaft
Can be set in the same manner as the furnace temperature.
In the section, each temperature of the hollow steel pipe, the concave support surface and the furnace
Similarly, hollow steel pipes can be circumferentially and longitudinally averaged.
High temperature heating that can be heated to one temperature and does not bend
I can. Further, the roller shaft portion is not cooled and has a cylindrical shape.
Temperature difference between the inside and outside
And therefore no bending of the roller shaft
A uniform circumferential load is applied to the tube support, that is, the rollers
As a result, no excessive load is applied to the bearing device
I can do it. In addition, the heat on the cylindrical roller shaft
Escape to the bearing side can be prevented by a heat shield
This allows the temperature inside the roller shaft to be uniform with the furnace temperature.
And heat conduction to the roller bearing side.
Lowering the rate of thermal damage to the bearing assembly
They can easily adopt ordinary bearing devices. And the hollow steel pipe in the hollow steel pipe support partBut
Contact centerHigh quality heat and wear resistant partsSex metalTo
More rollers reduce heat damage and reduce rollers
It can be used for a long time,
, Scale adhesion to rollers, roller pressure control, etc.
Can prevent product damage. As described above, according to the present invention, a cooling system is adopted.
Rollers and roller bearing devices
Can be prevented from being damaged by high heat.
Heating can be suitably performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional front view of a roller in a hollow steel pipe heating facility, showing one embodiment of the present invention. FIG. 2 is a partially cutaway side view of a heating furnace in the heating equipment for the hollow steel pipe. FIG. 3 is a vertical sectional side view of a main part of a heating furnace in the heating equipment for the hollow steel pipe. FIG. 4 is a vertical sectional front view of a heating furnace portion in the hollow steel pipe heating equipment. FIG. 5 is a cross-sectional plan view of a main part of a heating furnace in the hollow steel pipe heating equipment. FIG. 6 is a longitudinal side view of a roller in the heating equipment for the hollow steel pipe. FIG. 7 is a longitudinal sectional front view of a roller bearing device portion in the hollow steel pipe heating equipment. FIG. 8 is a plan view of a smoke exhaust system in the hollow steel tube heating system. FIG. 9 is a perspective view of a step of hot forming the hollow steel pipe. [Description of Signs] 1 Original pipe (hollow steel pipe) 3 Large-diameter rectangular steel pipe 10 Carrying floor 14 Round steel pipe forming mill 17 Square steel pipe forming mill 19 Cooling floor 20 Heating equipment 21 Heating furnace 26 Loading entrance 27 Loading exit 33 Lower heating burner 35 Upper heating burner 40 Roller conveyor 41 Roller 42 Roller shaft 43 Hollow steel pipe support 43A End 43B Central 44 Roller bearing 44A Inclined cylinder 44B Straight shaft 45 Roller shaft 46 Recessed support surface 47 Fitting groove 48 Fitting protrusion 50 Heat shield device 51 Insulation material 52 Outer shield plate 55 Inner shield plate 60 Bearing device 64 Bearing device 67 Collar 69 Rotary drive device 70 Smoke exhaust device 80 Carry-in conveyor 81 Carry-out conveyor A Welding

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C21D 1/00 115 C21D 9/08 F27B 9/24

Claims (1)

(57) [Claims] [Claim 1] The hollow steel pipe is transported in the longitudinal direction, is loaded into the heating furnace, is heated at a high temperature during the transport in the heating furnace, and is then removed from the heating furnace. A heating device for a hollow steel pipe to be provided, in which a roller conveyor for conveying the hollow steel pipe is disposed in a heating furnace, and each roller of the roller conveyor is fitted around a cylindrical roller shaft portion and the roller shaft portion. It is composed of a hollow steel pipe support portion and a roller bearing portion integrated at both ends of the roller shaft portion, and the roller shaft portion is formed of heat-resistant and wear-resistant steel.
The hollow steel pipe supporting portion has a pair of end portions and a central portion.
And these are externally fitted to the roller shaft and aligned.
Can, thereby forming a concave support surface in the roller axis direction over an outer surface, at least a central portion in the roller axis direction is formed by a high-quality heat and wear resistance of the metal,
The roller bearing is integrated with the end of the roller shaft
The outer diameter of the inclined cylinder with a smaller diameter toward the outside
It consists of an integrated solid rod-shaped straight shaft,
A shaft portion, each supported by a bearing device, heating equipment hollow steel pipe, characterized in that a heat shield device in the inclined cylindrical portion of the roller bearing unit.