Furnace inner roller of stepping furnace

Abstract

An in-furnace roller of a stepping furnace comprises a roller shaft, a roller body, a spherical plug, a heat shield, a positioning pin and a bolt hole, the roller shaft is divided into three sections, an external cooling water pipe is fixed to the first section, a transmission chain wheel is fixed to the second section, and the roller body and the spherical plug are fixed to the third section; the roller shaft and the spherical plug are connected and then fixed in an inner cavity of the roller body, a through hole is machined in the center of the roller shaft, and a cooling water pipe is placed in the through hole; an inner cavity is formed in the roller body; the assembly position of the roller shaft and the roller body is determined by the positioning pin, the roller shaft, the roller body, the spherical plug and the heat shield are fixed in an electric arc welding and bolt connection mode, the diameter of the arc at the bottom of the roller body is phi-phi + 30mm, and phi is the maximum diameter of a pierced billet; the arc angle of the maximum pierced billet diameter is 140-160 degrees; the width of the roller way ranges from 355 mm to 375 mm; four evenly-distributed water through holes with the diameter ranging from 40 mm to 60 mm are formed in the spherical plug in the circumferential direction. The household steel pipe conveying device can effectively prevent the surfaces of conveyed steel pipes from forming indentations and scratches.

Description

Technical Field

[0001] The utility model belongs to the technical field of steel pipe manufacturing and is an inner roller of a walking furnace. Background Art

[0002] Walking beam furnaces used for heat treatment in the industry typically utilize V-shaped rollers made of heat-resistant and wear-resistant alloys, with water circulation cooling to achieve sufficient cooling, which is expected to improve roller softening, deformation, and wear. However, this solution has some drawbacks: First, because the walking beam furnace maintains a high temperature of 900-980°C for extended periods during heating, the roller surface undergoes normalizing softening. Furthermore, the steel pipe and roller contact is two-point, making the roller surface susceptible to deformation and wear, resulting in grooves. Subsequent replacement of a small hole profile with a larger one will result in severe indentations and scratches, increasing product quality risks. Second, frequent hole profile changes shorten the manual maintenance cycle on the roller surface, significantly reducing production efficiency.

[0003] A few manufacturers use spray treatment technologies such as plasma spraying to apply reinforced ceramic or alloy coatings to the surfaces of furnace rollers. This approach has the following drawbacks: First, the roller substrate and coating are physically bonded, with a bond strength of 30 to 70 MPa, which cannot withstand the stresses of alternating hot and cold temperatures, the impact of steel pipe bending, or roller center shifting; second, spraying is expensive per unit area, making it less cost-effective than manual maintenance and equipment replacement.

[0004] Therefore, there is an urgent need for a new type of roller to replace the V-type roller. Utility Model Content

[0005] The utility model aims to provide a novel furnace roller of a walking furnace, which can effectively prevent indentations and scratches from being formed on the surface of a transported steel pipe.

[0006] The technical solution of this utility model:

[0007] A walking beam furnace roller comprises a roller shaft, roller body, spherical plug, heat shield, locating pins, and bolt holes. The roller shaft is divided into three sections: the first section secures an external cooling water pipe, the second section secures a drive sprocket, and the third section secures the roller body and spherical plug. The roller shaft and spherical plug are connected and fixed to the roller body's inner cavity. A through hole is machined in the center of the roller shaft, inside which the cooling water pipe is placed. The roller body has inner cavities on both sides. The assembly position of the roller shaft and roller body is determined by locating pins. The roller shaft, roller body, spherical plug, and heat shield are secured by arc welding and bolting. The arc diameter of the roller body bottom ranges from φ to φ+30 mm, where φ is the maximum rough pipe diameter; the arc angle of the maximum rough pipe diameter ranges from 140 to 160 degrees; and the roller table width ranges from 355 to 375 mm.

[0008] Furthermore, the spherical plug is provided with four evenly distributed water holes with a diameter of 40 to 60 mm in the circumferential direction to ensure sufficient flow and uniform cooling of cooling water in the roller body.

[0009] The beneficial effects of this utility model are as follows: 1) The use of a new furnace roller shape with a bottom arc diameter of the roller body ranging from the maximum rough pipe diameter φ to the maximum rough pipe diameter φ + 30mm can increase the contact area between the roller surface and the steel pipe, reduce the pressure acting on the roller surface, greatly reduce damage, and increase the life of the roller. It can adapt to the alternating production of multi-hole types and effectively avoid indentations and scratches on the surface of the conveyed steel pipe; 2) Since rough pipes have a wide variety of specifications, the head cannot maintain stable straightness after being removed from the pipe stripping machine. The use of a new furnace roller shape with a large arc angle can reduce the impact of the head bending on the roller surface and improve the surface quality of the steel pipe; 3) The roller width is increased to 365mm, which increases the support area for the steel pipe, reduces the phenomenon of local lack of support when the steel pipe is bent, and reduces indentations caused by local force concentration. 4) The spherical plug design increases the vertical through-hole and inner cavity volume, allowing the medium to flow fully, improving the cooling effect of the roller body, and effectively improving the high-temperature softening of the roller body. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0011] Figure 1 This is a schematic diagram of the furnace roller according to an embodiment of the present invention.

[0012] Figure 2 The following is a comparison chart of the main dimensions of the original roller table and the new type of in-furnace roller table.

[0013] Figure 3 Schematic diagram of a spherical plug.

[0014] Figure 4 To show the wear condition of single φ198mm and φ237mm hole steel pipes produced using modified furnace rollers.

[0015] Figure 5 The wear conditions of φ237 and φ198mm hole-type steel pipes produced in sequence using modified furnace rollers are shown.

[0016] Figure 6 The wear conditions of φ198 and φ237mm hole-type steel pipes produced in sequence using modified furnace rollers are shown.

[0017] Figure 7 The wear conditions of φ237, φ198 and φ237mm hole-type steel pipes produced in sequence using modified furnace rollers are shown.

[0018] Figure 8 The wear conditions of φ198, φ237 and φ198mm hole-type steel pipes produced in sequence using modified furnace rollers are shown.

[0019] In the figure: 1-bolt; 2-locating nut; 3-keyway; 4-roller shaft; 5-through hole; 6-roller body; 7-inner cavity of roller body; 8-water hole of spherical plug; 9-heat insulation cover; 10-spherical plug; 11-bolt; 12-heat insulation medium cotton; 13-water hole of roller shaft; 14-locating pin. DETAILED DESCRIPTION

[0020] The following is further described with reference to the embodiments of the accompanying drawings.

[0021] Figure 1 The figure shows a roller in a walking beam furnace, comprising a roller shaft 4, a roller body 6, a spherical plug 10, a heat shield 9, positioning pins 14, and bolts 11. The roller shaft 4 is divided into three sections: the first section secures an external cooling water pipe, the second section secures a drive sprocket, and the third section secures the roller body 6 and the spherical plug 10. The roller shaft 4 and the spherical plug 10 are connected and fixed to the inner cavity of the roller body 6. A through hole is machined in the center of the roller shaft 4, inside which the cooling water pipe is placed. The roller body 4 has inner cavities 7 on both sides. The assembly position of the roller shaft 4 and roller body 6 is determined by positioning pins 14. The roller shaft 4, roller body 6, spherical plug 10, and heat shield 9 are secured by arc welding and bolts 11. The arc radius of the bottom of the roller body 6 is 110-130 mm, and the arc angle is 140-160°. The roller table width is 355-375 mm.

[0022] Figure 3 As shown, the spherical plug 10 is provided with four evenly distributed water holes 8 with a diameter of 40-60 mm in the circumferential direction to ensure sufficient flow and uniform cooling of the cooling water in the roller body 6.

[0023] The arc radius of the roller bottom is 118.5 mm, the arc angle is 150°, and the roller width is 365 mm. In the embodiment, the V-shaped bottom of the roller is changed to a transition arc with a radius of 118.5 mm, and the angle is changed from 120° to 150°. The roller width is changed from 330 mm to 365 mm.

[0024] Figure 4 As shown in the following example: In case 1, only the φ237 hole-type mill is used to produce steel pipes. The bottom of the roller will gradually wear out. The diameter of the wear groove at the bottom is φ237mm. Only the φ237mm diameter steel pipes are produced, and the "sharp corners" of the groove edges of the steel pipes will not be scratched. Similarly, only the φ198mm diameter steel pipes are produced, and the "sharp corners" of the groove edges will not be scratched.

[0025] Figure 5 As shown: Case 2: First use the φ237 hole-type frame to produce steel pipes, and then replace it with the φ198 hole-type frame. The bottom of the roller will wear on the basis of the φ237mm diameter groove formed at the bottom for the first time, and will not cause "sharp corners" scratches on the edge of the groove to the steel pipe.

[0026] Figure 6As shown in Case 3: First, a φ198 hole-type stand is used to produce steel pipes, and then a φ237 hole-type stand is replaced. The bottom of the roller will initially form a φ198mm diameter groove at the bottom. Even if the roller has "pointed corners" after processing the small steel pipe, the arc radius of the roller bottom supports the steel pipe and will not cause scratches on the steel pipe due to the "pointed corners" of the groove edge. Due to the increased roller angle and improved bottom circular radius, the pressure acting on the φ237mm steel pipe can also be reduced, greatly reducing damage and extending roller life.

[0027] Figure 7 As shown in the following example: Case 4: First, a φ237 hole-type mill was used to produce the steel pipe, then a φ198 hole-type mill was used, and finally a φ237 hole-type mill was used. Similar to Case 3, when the φ237mm steel pipe was processed for the third time, the large steel pipe would overlap with the shape left by the first processing, and the groove left by the second processing was not deep enough, so no "sharp corner" scratches would be generated on the large steel pipe during the third processing.

[0028] Figure 8 As shown in the following example: Case 5: First, a φ198 hole-type mill was used to produce the steel pipe, then a φ237 hole-type mill was used, and finally a φ198 hole-type mill was used. Similar to Case 4, when the φ198mm steel pipe was processed for the third time, the steel pipe would overlap with the shape left by the first processing, and the groove left by the second processing was not deep enough, so no "sharp corner" scratches would be generated on the large steel pipe processed for the third time.

Claims

1. A roller in a walking beam furnace, comprising a roller shaft, a roller body, a spherical plug, a heat shield, a positioning pin, and a bolt hole. The roller shaft is divided into three sections. The first section is fixed with an external cooling water pipe, the second section is fixed with a transmission sprocket, and the third section is fixed with the roller body and the spherical plug. The roller shaft and the spherical plug are connected and fixed in the roller body cavity. A through hole is machined in the center of the roller shaft, and a cooling water pipe is placed inside the through hole. Inner cavities are set on both sides of the roller body. The assembly position of the roller shaft and the roller body is determined by positioning pins. The roller shaft, roller body, spherical plug and heat shield are fixed by arc welding and bolt connection. The characteristics are: The arc diameter of the roller bottom is φ~φ+30mm, φ is the maximum rough pipe diameter; the arc angle of the maximum rough pipe diameter is 140~160°; the roller width is 355~375mm.

2. The roller in a walking beam furnace according to claim 1, characterized in that: The spherical plug is provided with four evenly distributed water holes with a diameter of 40~60mm in the circumferential direction.

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