Shuanghu Production Base, Daxin Town,
Jimo District, Qingdao City, Shandong Province, China
With the pursuit of high efficiency and efficiency in enterprise production management, metallurgy, building materials, industry, wharf, mine and so on put forward the requirements of high efficiency, large capacity and large inclination for conveyor. New belt type-large side-shielding conveyor belt is the preferred equipment to meet the above requirements. Because of the working characteristics and structural form of the new belt type, the high quality requirements of long service life and high reliability performance are put forward. The conveyor belt is the key part of the conveyor, and it is the realization of large inclination angle (maximum inclination angle p). Up to 90. To optimize the performance and improve the quality of the necessary parts for efficient continuous conveying is the basis for the new belt type to meet the user's requirements and occupy the market.
1. Configuration and working state of side-blocking conveyor belt < br />. The reason why the sidewall conveyor belt (machine) can realize high inclination, high efficiency and large capacity transportation is determined by its unique structure form. Its structure form, working state and transmission mode are as follows < br />. 1A and B are shown (frame is not drawn). The conveyor belt is a flexible chain bucket structure with two wavy edges attached along both sides of the flat base belt body (Fig. 1A and B part 8) (Fig. 1A and B part 9), and the transverse pocket board is arranged between the wavy edges. The three parts are bonded and vulcanized to form a whole. The belt body bonded by the three parts can be combined to form a flexible chain bucket structure, thus realizing high-efficiency conveying with large inclination angle, and keeping the bulk material conveyed from sliding. No retreat. When the width of the belt body is more than 1400 mm and the height of the retaining edge is more than 240 mm, it is often called a large wavy conveyor belt. At present, the largest conveying capacity of the large-scale side-blocking conveyor belt (machine) used in China is 1000-1200m3/h, and the traction power is 100-180kW. It is a new subject to optimize the performance and prolong the service life of large-scale heavy-duty side-blocking conveyor belts which are difficult to manufacture, and to study and improve the reliability and technology to meet the needs of high-efficiency conveying at close distance and large inclination angle.
2 Quality optimization and technical improvement
2.1 The optimization and improvement of belt material is to meet the load-carrying capacity and < br /> of large-scale heavy-duty side-retaining conveyor belt. The specific measures for optimizing and improving the material used in traction power are as follows:
Nbsp; & nbsp; (1) polyester cord fabric with high tensile strength is selected as the tensile body of flat base ribbon skeleton material, and its tensile strength is 200 kg/2.5 cm, which is three times that of common cotton canvas; < br />
Nbsp; & nbsp; (2) in order to improve the wear resistance and fracture resistance of FLAT-BASE ribbon and wavy ribbon, a suitable amount of polyester staple fibers were added into the colloid, and the amount of polyester staple fibers could be selected and used in 10%-20% according to the performance requirements of the colloid. In order to improve the adhesion between polyester staple fibers and colloidal interface, the polyester staple fibers used must be pretreated by improving the wettability before they participate in the mixing of rubber. The tear strength and tensile strength of the waveform edge can reach 80~kN.m~ and 20~26MPa respectively after adding short fibers, which is ideal for improving the colloidal properties.
2.2 Optimization and Improvement of Structural Form
2.2.1 In order to improve the carrying capacity of the belt body, the transverse bending deformation of the belt body after loading is the smallest. That is to say, improving the transverse rigidity of the belt body is the key to reduce the transverse bearing deformation of the belt body and increase the carrying capacity of the belt body. The transverse rigidity value of the belt refers to the ratio of the bending weight of the belt body to the width of the belt body caused by the self-weight of the belt body on both sides of the edge of the free support belt body in the transverse vertical section of the belt body. The technical standard for transverse rigidity value of high transverse rigidity side-retaining conveyor belt is not more than 0.05. After optimizing and improving the structure of belt body, the transverse rigidity detection value of belt body is 0.036 after adding transverse rigidity strengthening layer, and the transverse rigidity of belt body is < br/> after bearing. With the decrease of deformation, the bearing capacity can be increased by 15%-20%. The effective measure to improve the transverse rigidity of large-scale heavy-duty side-retaining conveyor belt is to install a special composite adhesive layer of polyester staple fibers mixed and calendered between layers of multi-layer pull-resistant canvas of flat base belt body, that is, the adhesive layer embedded in the adhesive layer along the transverse single direction of the belt body, which can increase the transverse bending resistance of the belt body < br/>. The transverse rigidity of the belt body can be increased by 2.5 times compared with that of the conveyor belt with common structure, even if the transverse rigidity of the belt body is increased from 0.09 to 0.036.
2.2.2 When the waveform baffle adopts double S-shaped stretching structure belt body, it bends along the radius of the drum in the transmission envelope angle range, so that the waveform baffle and the screw of the pocket plate are < br/> when it stretches. In order to reduce the deformation and stress of the retaining edge at the connection with the stud during the retrofitting extension, a small "S" expansion edge is adopted at the connection of the stud because of the small "S" extension < br/>. The shrinkage deformation is small when changing direction, so it can reduce the stress caused by changing direction deformation, and play an optimum role in prolonging the working life of the retaining edge. The improvement of double S-shaped expansion retaining edge is very beneficial for reducing deformation stress of large conveyor belt retaining edge.
2.2.3 Paddle Plate is composed of composite structure. Its structure is shown in Fig. 4. Its main advantages are < br />.
(1) The manufacturing process is good, the vulcanizing die is simple and easy to manufacture. The structure is simplified and the vulcanization quality of the product is easily guaranteed by the partitioning of the hoop plate.
The structure of the hoop plate is simplified and the vulcanization quality of the product is easily guaranteed.
(2) The vertical plate after fragmentation can be replaced after wear, which is beneficial to prolong the service life of the belt body; (3) the floor plate of the pocket plate is more convenient to use special die when bonding and vulcanizing with the flat base belt body due to the removal of the vertical plate;
(4) The setting of the bending angle of the vertical plate increases the < br /> of the sideband when conveyed at a large inclination angle. Loading capacity provides storage space and increases conveying capacity.
2.2.4 Bolts are used to strengthen the connection between the pocket plate and the retaining edge. Its main function is to improve the bearing capacity of the pocket plate, overcome the back bending deformation of the pocket plate after loading, and prevent the deformation damage of bulk materials from extruding the retaining edge at both ends of the pocket. Therefore, the stress state of the pocket plate and the retaining edge can be effectively optimized and the bearing capacity can be improved.
2.3 Adhesive vulcanization process and effect In order to optimize manufacturing process, flat base belt < br /> is adopted for side-retaining conveyor belt. The body, retaining edge and pocket board are made in three parts, then bonded by the three parts and vulcanized by the bonding surface (also called secondary vulcanization) to make them become the integral belt of the flexible chain bucket structure (see Fig. 1). The main purpose of vulcanization is to improve the bonding strength and ensure the uniformity of the bonding strength. In production, the wavy side-shielding conveyor belt is made of three parts in order to < br />.
(1) making vulcanization die easier; < br />
(2) It is convenient to formulate vulcanization process according to the different thickness of the parts, and it is helpful to improve the quality of vulcanization and realize the comprehensive control of the best durability. The bonding strength can be increased by 3-3.5 times by vulcanization instead of cold bonding.