Wear prevention measures for belt conveyors

The wear forms of conveyor belt and preventive measures for belt conveyors. Belt conveyors are the most important part of the conveying equipment. The lifespan of belt conveyors largely depends on the lifespan of the conveyor belt. Generally, the cost of the conveyor belt accounts for 30% to 50% of the total cost of the belt conveyor. Therefore, in the design of belt conveyors, taking corresponding measures to reduce the wear of the conveyor belt and extend its lifespan has practical significance for the normal operation of the belt conveyor and the reduction of maintenance costs.

1. Wear forms of conveyor belt

The normal service life of the conveyor belt depends on the wear condition of the conveyor belt. The damage of the conveyor belt is mostly manifested as wear on the working surface (i.e., the covering layer) and the edges.

(1) Wear of the conveyor belt covering layer

The wear of the covering layer is mainly caused by the relative sliding of the conveyor belt and the conveyed materials, and is also related to the friction between the various components of the conveyor. The wear forms and influences of the conveyor belt covering layer are shown in the table.

(2) Wear of the conveyor belt edges

The wear of the conveyor belt edges is mainly caused by the deviation of the conveyor belt from the center line due to deviation. The conveyor belt should run on the center line of the idler group, but due to manufacturing, installation, and usage defects of the conveyor, the conveyor belt often deviates from the center line and runs off center. Usually, the conveyor belt is allowed to have a 5% deviation in the width direction. When the deviation is too large, the conveyor belt comes into contact with the idler frame and the machine frame, causing edge rubber wear. Severe deviation may even cause the conveyor belt to curl, such as the radial screw heads of the drum, the cleaning block, and other protrusions on the frame, or the frame gap being too small, which can easily cause the conveyor belt to tear, local peeling of the covering rubber and scratches.

2. Preventive measures

By analyzing the wear factors of the conveyor belt, corresponding preventive measures are taken in the design of belt conveyors to extend the service life of the conveyor belt. Usually, the design is optimized from the following five aspects to reduce the wear of the conveyor belt.

(1) Selecting conveyor belts reasonably

The selection of conveyor belts needs to consider various factors, mainly: the relevant requirements of the conveyor system for the conveyor belt; the requirements of the terrain environment conditions and safety aspects; the types, forms, and characteristics of the conveyed materials, the required belt width, working tension, and conveying capacity; the minimum diameter of the drum; the formability and lateral stiffness; load support; the length of the curve section and transition section; the tensioning method and stroke, the receiving point and receiving conditions of the conveyor belt, as well as the operating cycle of the conveyor belt; requirements for impact resistance and tear resistance, joint conditions, etc.

Based on the relevant conditions, the selection of the conveyor belt should focus on the following three aspects.

① The shape and structure of the conveyor belt. Different conveying methods (such as flat type, slot type, large inclination angle, etc.) determine the conveying capacity of the conveyor belt and are limited by terrain and environmental conditions. It is the premise for determining the material of the tensile body of the conveyor belt, the size of the safety factor, and the length of the conveyor belt required.

② Selection of core material and structure of the conveyor belt. The performance of the conveyor belt is closely related to the core material, structure, and number of layers of the conveyor belt. Multi-layer cotton canvas conveyor belts have low strength, many layers, are not resistant to fatigue, prone to mold and corrosion, heavy in weight, and have high energy consumption, and have been gradually phased out; nylon conveyor belts have high strength, large elasticity, light weight, good impact resistance and bending performance, good formability performance, superior moisture resistance, water resistance, and other properties to cotton canvas conveyor belts, but they have a large elongation, and when the tensioning stroke can be set longer, nylon belts can be preferred; polyester core has similar strength to cotton nylon, has all the advantages of nylon belts, has a higher elastic modulus, a smaller elongation rate, and better dimensional stability, and is an ideal conveyor belt.

③ Selection of covering layer. The selection of the covering layer includes covering materials, surface morphology and thickness. The main components of the covering layer are various rubber and plastics. The type and model of covering materials to be selected must be considered based on the types of conveyed materials, operating conditions and working environment. The thickness of the covering layer should be determined based on the wear rate, the receiving conditions, the wear resistance and impact resistance of the covering layer, as well as the operating cycle of the conveyor belt.