1. Conveyor belt The belt conveyor belt is similar to the ordinary conveyor belt, but some important techniques are also adopted in the design. Due to the rigidity and flexibility requirements, a special skeleton structure must be used. The conveyor belt must be rigid so as to form and maintain a circular tubular shape as it passes through the idler set. At the same time, there must be some flexibility to ensure that the conveyor belt can pass through the transition section, roll in a circular tubular shape in the line via the feeding section and discharge through the drum in a planar manner. This can be satisfied by adding a rubber layer between the fabric layers of the conveyor belt.
In order to ensure that the lap portion is well sealed to prevent material leakage, the rigidity of the edge of the belt is reduced. Further, it is necessary to control the thickness of the upper and lower adhesive layers and the number of vulcanizations, and to improve the ability of the conveyor belt to naturally tend to be round and tubular.
For long-distance round tube belt conveyors, the conveyor belt can also be constructed with a steel cord core. At this time, a layer of transverse fabric is laid on the upper and lower sides of the rope. Just like the fabric core conveyor belt structure, there is also a layer of rubber between the fabric and the wire rope. For emergency repairs, metal joints can be temporarily used or replaced with ordinary conveyor belts for long-term maintenance.
Ordinary conveyor belts do not have the required rigidity and flexibility, resulting in permanent core delamination, fatigue or other unpredictable problems. However, the advantages of the ordinary conveyor belt are that the structure is simple, the manufacturing cost is low, the price is low, and sometimes it can be used as a substitute for the round pipe conveyor belt. When used on a universal belt conveyor, the service life of a round belt conveyor belt and a conventional conveyor belt is virtually the same.
The cleaning device for the round tube conveyor belt is the same as that used in the general belt conveyor, and the single and multi-blade belt cleaners as well as the rotary brush and the empty section cleaner can be applied.
Round tube belt conveyor belts can be specially manufactured to transport hot materials. Special consideration must be given to the particle size and the surface temperature of the conveyor belt when selecting the conveyor belt. The very hot conveyor belt surface can have a significant effect on the life of the conveyor belt.
2. Roller and its spacing When the round belt conveyor runs straight, without any vertical or horizontal bending, the bottom three strokes of the upper stroke (or the carrying side of the round belt conveyor) bear the conveyor belt and materials. The weight of the top three rollers maintains the conveyor belt in a round tubular shape. When the conveyor has vertical and horizontal curved portions, the other rollers surrounding the conveyor belt may become load carrying rollers, and the remaining rollers maintain the tubular shape of the conveyor belt. The same is true for the lower stroke (ie, the return stroke of the round belt conveyor). Instead of using a flat belt like a universal belt conveyor, the conveyor belt is held in a circular tubular shape during the downstroke or return stroke in order to ensure that the conveyor belt is guided through the vertical or horizontal curved section in the same structural dimensions as the load bearing side.
The rollers around the conveyor belt are commonly referred to as round tubular retaining rollers (PSK idlers). The diameter and spacing of the roller sets are determined by the size of the round belt conveyor and the material being conveyed. Due to the high rigidity after the tube is formed, the distance between the rollers is relatively large compared to the general conveyor when the sag of the conveyor belt satisfies the requirements. The rollers constituting the polygonal roller group can be mounted on both sides of the roller panel to prevent the running conveyor belt from being caught in the gap between the rollers to cause an accident.
In the transition section of the tail of the conveyor (the conveyor belt is rolled into a circular tube shape by a flat belt), the conveyor belt is supported by a roller set of different groove angles, similar to a universal belt conveyor. Here, the conveyor is loaded by the guide trough to ensure that the material is added near the longitudinal center line of the conveyor belt, which is beneficial to the operation of the conveyor belt. The roller located at the center of the conveyor belt under the feeding side plate can absorb the impact of the loading material. Load. A special set of rollers is placed at the beginning of the circular tube, consisting of 12 two hexagonal rollers arranged in a non-coincident manner. The circular tube shape of the 12-sided roller set is closer to a circle than the standard hexagonal roller set and can withstand the high load pressure at the seal. In addition to these rollers, a special set of guide rollers are used to hold the conveyor belt lower than the other before the conveyor belt is rolled up. This roller is mounted on the front of the first polygonal roller set to eliminate wear on the edge of the conveyor belt and properly overlap and close the conveyor belt.
Roller alignment and proper loading play a key role in the stability and guidance of the round belt conveyor. In a universal belt conveyor structure, the roller brackets are aligned in the horizontal and vertical planes, which is very important for the correct guiding of the conveyor belt and the completion of the operation, and the adjustment roller is used to adjust the incorrect guiding or conveyor belt deviation. . Since the belt conveyor belt is guided by the rollers on each side of the circumference, the conveyor can pass the bend and overcome the problem of the center deviation of the conveyor belt. During the operation of the round tube belt conveyor, the idler can still be adjusted so that the overlapping portion of the conveyor belt is as far as possible on the carrying side. However, in fact, it is the weight of the material to be conveyed that mainly stabilizes the conveyor belt and keeps its overlapping portion at or near the upper position. The center of gravity of the material with a cross-sectional area of ​​75% of the tube area maintains the conveyor belt with proper dynamic performance. On the return or unloaded side, the overlapping portion of the conveyor belt is located below the circular tube shape, and the weight of the lap joint maintains proper dynamic performance during the return stroke.
3. The curved round tube belt conveyor is superior to the universal belt conveyor. It is characterized by small radius turning, which reduces the contour and can not be used geographically. It can not use the universal belt conveyor or multiple reload points. In the case of a round tube belt conveyor. Since the belt conveyor belt is completely restrained by the surrounding rollers, no deviation occurs in comparison with the general belt conveyor. The round tube belt conveyor can be bent on the vertical and horizontal planes, or can be bent on both sides at the same time, eliminating the transfer point, and passing the obstacles such as existing plant equipment from the side, the top or the bottom, the conveyor belt The bending begins after the formation of the round tube through the transition section, and the bending must be completed before reaching the transition section of the discharge drum. The transitions at both ends of the conveyor must be straight.
The bend radius is usually determined by the diameter of the tube, the type of belt, and the bending used. It is generally recommended to use a standard minimum radius. When horizontal or concave bending, the fabric core strip is 300 times the diameter of the round tube, and the steel cord core strip should be 700 times the diameter of the round tube; but if it is "S" shaped, convexly curved or The horizontal and concave bending are combined, the minimum radius, the fabric core strip is 400 times the diameter of the round tube, the steel cord core strip should be 800 times the diameter of the round tube; the minimum radius in the case of both horizontal and convex bending, fabric The core strip is 500 times the diameter of the round tube, and the steel cord core strip should be 900 times the diameter of the round tube. The foregoing is only a general case. In general, the final decision on the radius depends on the engineer's consideration of the static, dynamic tension of the particular conveyor and the type of bending used.