Improved long return roller and long return roller group including same

Abstract

To provide a group of long return rollers capable of improving durability against concentrated contact between a belt and the central part of a long return roller, preventing central part cracking, making replacement work easy at low cost and without becoming too heavy even when a countermeasure against cracking is taken for the long return roller, and preventing central part cracking. [Solution] An improved long return roller 2 having an 8 mm thick rubber ceramic sheet 5 fixed over a width of 200 mm around the longitudinal center of the roller section 4, and a long return roller group having three or more improved long return rollers 2 arranged on the underside of the return side belt.

Description

[Technical field]

[0001] The present invention relates to an improved long return roller for a belt conveyor having anti-wear measures, and to a group of long return rollers arranged including the improved long return roller. [Background technology]

[0002] In steelworks, belt conveyors are widely used to transport raw materials for pig iron production, but since powder accumulates on the return belt, it is necessary to clean it with a belt cleaner. However, it is impossible to completely remove this dust, and the belt cleaner itself deteriorates over time, reducing its cleaning function. As a result, the return roller comes into contact with the dust on the return side of the belt, and the dust and the weight of the belt conveyor on the return roller cause wear, which can lead to cracking. To address these issues, the following prior art has been disclosed. For example, Patent Document 1 (Japanese Utility Model Application Publication No. 54-93990) describes that when sticky substances such as pitch and tar are transported by belt conveyor, by covering the return roller that comes into contact with the belt surface with a rubber-like elastic body having a thickness of 1 mm or more, adhesion of the transported substances can be prevented and long-term operation can be made possible (see especially specification, page 4, lines 5-10 and figure 2).

[0003] Furthermore, Patent Document 2 (JP Patent Publication 77234 / 1997) describes that when a ceramic ring (4) is used in a disc roller (3) for a return roller, by inserting a rubber plate (5) having a thickness of 1 mm to 50 mm as a shock absorbing material between the core metal (1) and the ceramic ring (4), the roller is more durable than a conventional metal roller, has no performance problems, and is advantageous in terms of economy and safety (see especially paragraph 0009 and Figure 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 54-93990 [Patent Document 2] Japanese Patent Application Publication No. 9-77234 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the belt conveyor described in Patent Document 1 is intended to prevent adhesion of sticky substances, and is not suitable for abrasive substances such as iron ore. Furthermore, the disc roller for the return roller described in Patent Document 2 has a problem in that it has a complex structure and is costly. Furthermore, the return belt of the belt conveyor that transports iron ore or coke is covered with powdery material that cannot be completely scraped off by the cleaner. This powder can come into contact with the return roller, causing wear on the surface of the return roller and leading to breakage. In particular, belt conveyors with a belt width of 1400 mm or more have a heavy belt weight (27 kg / m for 1400 mm, 33 kg / m for 1600 mm), and the load on the long return rollers is large, which causes concentrated contact between the belt and the center of the long return roller, often resulting in core cracks (central core cracks account for more than 90% of defects). In order to solve these problems, the present invention has as its first objective the improvement of durability against concentrated contact between the belt and the center of the long return roller and the prevention of central cracking. The second objective is to provide an improved long return roller that is inexpensive and easy to replace even when measures to prevent cracking are taken on the long return roller without becoming too heavy. A third object of the present invention is to provide a long return roller group capable of reducing concentrated contact between the belt and the center of the return roller and preventing central cracking. [Means for solving the problem]

[0006] The invention according to claim 1 to solve the above problem is as follows: In a belt conveyor having a belt width of 1400 mm or more, an improved long return roller is provided which is composed of a rotating shaft portion and a roller portion disposed on the underside of a return side belt and supports the underside of the return side belt, The center of the roller in the longitudinal direction only Around the Over mm 500mm below 5 mm thick Over mm 15mm below The wear-resistant sheet is fixed to the surface of the bearing.

[0007] The invention according to claim 2 provides an improved long return roller according to claim 1, The abrasion-resistant sheet is characterized in that it is a rubber ceramic sheet.

[0008] The invention according to claim 3 is characterized in that the improved long return roller according to claim 1 or 2 and a normal long return roller having no wear-resistant sheet attached to the roller portion are alternately arranged at a predetermined interval on the underside of the return belt in three or more units. The long return roller group is characterized by the above. Effect of the Invention

[0009] The improved long return roller of the invention according to claims 1 and 2 has a longitudinal center of the roller part. only Around the Over mm 500mm below 5 mm thick Over mm 15mm below Since an abrasion-resistant sheet (rubber ceramic sheet in claim 2) is fixed, durability against concentrated contact between the belt and the center of the improved long return roller is improved, and central cracking can be prevented. Furthermore, compared with a long return roller having an abrasion-resistant sheet fixed to the entire periphery of the roller portion, the weight is lighter, making replacement easier, and the amount of abrasion-resistant sheet used is reduced, making it possible to provide an improved long return roller with measures to prevent cracking at a low cost.

[0010] The long return roller group of the invention according to claim 3 is composed of three or more improved long return rollers according to the invention according to claim 1 or 2, which have been provided with anti-wear measures, and normal long return rollers, which do not have an anti-wear sheet fixed to the roller portion, arranged alternately at a specified interval on the underside of the return belt, thereby mitigating concentrated contact between the belt and the center of the return roller and preventing central core cracking. Also, since the number of improved long return rollers according to the invention according to claim 1 or 2 can be reduced, a long return roller group capable of preventing central core cracking can be provided at a lower cost. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side view of a belt conveyor according to a first embodiment in which an improved long return roller is applied. [Diagram 2] A front view of a standard long return roller. [Diagram 3] A front view of the improved long return roller. [Figure 4] FIG. 2 is an explanatory diagram of a roller stand used in manufacturing an improved long return roller. [Diagram 5] FIG. 11 is a side view of a belt conveyor according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiment of the present invention will be described with reference to examples. EXAMPLES

[0013] The belt conveyor according to the first embodiment shown in FIG. 1 includes a drive pulley 11 rotated by a motor (not shown), a driven pulley 12 rotated following the drive pulley 11, a drive side snap pulley 13 arranged on the lower side near the drive pulley 11, a tension pulley 14 arranged on the lower side near the driven pulley 12, a drive side bend pulley 15 arranged on the drive pulley 11 side above the tension pulley 14 (left side in FIG. 1) and supporting the lower surface of the return side belt 18b, a driven side bend pulley 16 arranged on the driven pulley 12 side above the tension pulley 14 (right side in FIG. 1) and supporting the lower surface of the return side belt 18b, and a driven side snap pulley 17 arranged on the lower side near the driven pulley 12. The drive pulley 11, the drive side snap pulley 13, the drive side bend pulley 15, tension It is equipped with a pulley 14, a driven bend pulley 16, a driven snap pulley 17 and a belt 18 (width 1600 mm) wound around the driven pulley 12, and eight improved long return rollers 2 that support the underside of the return side belt 18b. and a drive bend pulley 15, tension The pulley 14 and the driven bend pulley 16 constitute a tension section 19. tension The belt 18 can be kept in a tensioned state at all times by a constant force exerted by the weight of the pulley 14. The belt conveyor according to the first embodiment conveys an object (not shown) such as raw materials for iron making placed on the upper surface of the conveying belt 18a in a conveying direction (the direction of the right arrow in FIG. 1) by rotating the driving pulley 11. At this time, the return belt 18b moves in a return direction (the direction of the left arrow in FIG. 1) opposite to the conveying direction.

[0014] As shown in FIG. 2, a typical long return roller 1 is made up of a rotating shaft portion 3 (length 1730 mm, diameter 30 mm) and a roller portion 4 (length 1630 mm, diameter 300 mm). The improved long return roller 2, which is the main part of the present invention, has a rotating shaft portion 3 and a roller portion 4 of the same configuration as the normal long return roller 1, and as shown in FIG. onlyA rubber ceramic sheet 5 having a thickness of 8 mm is fixed around the circumference of the belt conveyor over a width of 200 mm. In the belt conveyor according to the embodiment 1 shown in Fig. 1, seven improved long return rollers 2 are arranged at regular intervals between the driving side snap pulley 13 and the driving side bend pulley 15 to form an improved long return roller group. In addition, one improved long return roller 2 is arranged between the driven side snap pulley 17 and the driven pulley 12.

[0015] FIG. 4 is an explanatory diagram of a roller stand 6 used when fixing a rubber ceramic sheet 5 to the roller portion 4 of the improved long return roller 2. The improved long return roller 2 is manufactured by the following procedure. (Step 1) Prepare a regular long return roller 1. (Step 2) The periphery of the center in the longitudinal direction of the roller part 4 is sanded over a width of about 220 mm using an electric sander (not shown). (Step 3) Prepare a rubber ceramic sheet 5 having a width of 200 mm, a length of 992 mm, and a thickness of 8 mm. After polishing the back side, rubber cement is applied to it. (Step 4) As shown in Figure 4, the rotating shaft 3 of the normal long return roller 1 is placed on the support part 7 of the roller stand 6. Then, while rotating the normal long return roller 1, rubber cement 8 is applied to the center of the roller part 4 with a 200 mm long brush. (Step 5) The normal long return roller 1 with the rubber cement 8 applied thereto is left on the roller stand 6 for 20 minutes. (Step 6) The rubber ceramic sheet 5 to which rubber cement has been applied in step 3 is wrapped around the portion of the normal long return roller 1 to which rubber cement 8 has been applied that has been left for 20 minutes in step 5, and pressure is applied from all around by, for example, hitting the surface side of the rubber ceramic sheet 5 with a hammer.

[0016] After manufacturing eight improved long return rollers 2 by steps 1 to 6 above, seven improved long return rollers 2 are arranged at regular intervals between the driving side snap pulley 13 and the driving side bend pulley 15, and one improved long return roller 2 is arranged between the driven side snap pulley 17 and the driven pulley 12, thereby completing the belt conveyor of Example 1 shown in Figure 1. The completed belt conveyor was put into test operation for a year and a half, and the degree of wear of the rubber ceramic sheet 5 fixed to the roller part 4 was checked, and it was found to be about 30%. Based on this result, the service life of the improved long return roller 2 is estimated to be about 4 years. EXAMPLES

[0017] FIG. 5 is a side view of the belt conveyor according to the second embodiment. The belt conveyor according to the embodiment 2 differs from the belt conveyor according to the embodiment 1 only in that, instead of the improved long return roller group consisting of seven improved long return rollers 2 arranged between the drive side snap pulley 13 and the drive side bend pulley 15 in the belt conveyor according to the embodiment 1, a long return roller group consisting of three normal long return rollers 1 and four improved long return rollers 2. Therefore, the configuration other than the long return roller group will be described in FIG. 5 using the same numbers as in FIG. 1 to FIG. 3.

[0018] The long return roller group according to Example 2 is disposed between the drive side snap pulley 13 and the drive side bend pulley 15, similarly to the improved long return roller group according to Example 1, but of the seven improved long return rollers 2 in Example 1, the second, fourth, and sixth improved long return rollers 2 from the drive side snap pulley 13 are replaced with normal long return rollers 1. That is, in Example 2, the long return roller group is constituted by alternately disposing four improved long return rollers 2 and three normal long return rollers 1 at regular intervals. The reason for this configuration is that evaluation tests were conducted on various long return roller groups combining normal long return rollers 1 and improved long return rollers 2, and it was found that the normal long return rollers 1 on both sides of the improved long return roller 2 had less wear in the center.

[0019] Modifications of the first and second embodiments are listed below. (1) The belt width of the belt conveyor in Examples 1 and 2 was 1600 mm. However, if the belt width is 1400 mm or more, the effect of preventing central body cracking can be obtained. When the belt width is 1200mm, wear due to contact with the belt is seen near both ends and near the center of the roller, but head plate damage is more common near both ends than center body crack damage near the center. Also, when the belt width is 1050mm or 750mm, wear due to contact with the belt is seen near both ends of the roller, and head plate damage is mostly near both ends. (2) In the improved long return roller 2 in Examples 1 and 2, the center of the roller portion 4 in the longitudinal direction only A rubber ceramic sheet 5 having a thickness of 8 mm was fixed around the circumference of the casing over a width of 200 mm. However, the width is not limited to 200 mm and may be as wide as 150 mm. Over mm 500mm below The thickness is not limited to 8mm. Over mm 15mm below Within this range, the durability against concentrated contact at the center between the belt 18 and the improved long return roller 2 can be improved, and the amount of the rubber ceramic sheet 5 used can be reduced. However, considering economy and ease of installation, the width is 150 Over mm 300mm below , thickness is 5 Over mm 10mm below It is better to keep it in the range. Moreover, instead of the rubber ceramic sheet 5, an abrasion-resistant sheet made of other abrasion-resistant rubber or abrasion-resistant resin such as ultra-high molecular weight polyethylene, POM (polyacetal), or PTFE (fluororesin) may be fixed. (3) In the belt conveyor of Example 1, seven improved long return rollers 2 are arranged alternately at regular intervals between the drive side snap pulley 13 and the drive side bend pulley 15 to form an improved long return roller group, and in the belt conveyor of Example 2, four improved long return rollers 2 and three normal long return rollers 1 are arranged alternately at regular intervals between the drive side snap pulley 13 and the drive side bend pulley 15 to form a long return roller group, but the intervals are not limited to regular intervals and may be any predetermined interval. (4) In the belt conveyors of Examples 1 and 2, between the drive side snap pulley 13 and the drive side bend pulley 15, the normal long return roller 1 and the improved long return roller 2 are arranged along a straight line, and the belt 18 is hung in a straight line, but they may be arranged along a curve. When arranging them along a curve, placing the improved long return roller 2 near the inflection point of the curve and arranging the normal long return roller 1 or the improved long return roller 2 before and after it at short intervals (approximately 1 to 2 m intervals) can alleviate concentrated contact between the belt 18 and the central part of the roller section 4, thereby improving the effect of preventing central body cracking. [Explanation of symbols]

[0020] 1 Normal long return roller 2 Improved long return roller 3 Rotating shaft 4 Roller part 5 Rubber ceramic sheet 6 Roller stand 7 Support part 8 Rubber glue 11 driving pulley 12 driven pulley 13 driving side snap pulley 14 Tension pulley 15 Drive side bend pulley 16 Driven bend pulley 17 Driven snap pulley 18 Belt 18a Conveyor belt 18b Return belt

Claims

1. In a belt conveyor having a belt width of 1,400 mm or more, an improved long return roller is provided which is configured to support the underside of a return belt and includes a rotating shaft portion and a roller portion disposed on the underside of the return belt, An abrasion-resistant sheet having a thickness of more than 5 mm and not more than 15 mm is fixed to the circumference of only the center of the longitudinal direction of the roller part over a width of more than 150 mm and not more than 500 mm. Improved long return roller.

2. The wear-resistant sheet is a rubber ceramic sheet.

2. The improved long return roller of claim 1.

3. The improved long return roller according to the invention of claim 1 or 2 and a normal long return roller having no wear-resistant sheet fixed to the roller portion are alternately arranged at a predetermined interval on the underside of the return belt in three or more units. A group of long return rollers.

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