Daily troubleshooting and maintenance skills for belt conveyor

3/4/2012 5:20:07 PM

Belt machine, which is also called belt conveyor, is widely used for transporting machinery in mining, chemical, cement plant.

Technical advantages of belt machine (conveyer):

First, belt conveyor operates reliably. In many important production units which need continual operation, such as transportation of coal in power plant, scattered material in iron and steel plant or cement plant, and stevedoring in port, belt conveyors are used widely. Because it would bring sever loss if machines shutdown in these occasions, while belt conveyor can work continuously.

Second, Belt conveyor makes low power consumption. Due to the un-relative movement between material and conveyor, the running resistance is make small (about 1 / 3-1 / 5 of scraper conveyer), and attrition and fragmentation are also small, which is helps for high productivity an beneficial to reduce the production cost.

Third, belt conveyor has adaptable and flexible conveying line. The length of the line is set according to specific circumstance which can be several meters or more than 10km. Equally, belt conveyor can be installed in a small tunnel, also can be mounted on the chaos ground and dangerous area in the sky.

Forth, According to the process requirements, belt conveyor can be fed flexibly from one or more points and unloads to several sections. Belt conveyor would become a major transportation route when it is fed simultaneously from several points (such as the conveyor used in coal bunker) or fed evenly from any point along the belt.

Fifth, belt conveyor can take material from the roadway under coal stockpile; when needed, it can also mix with different piles of material. The material can be unloaded simply from the conveyor head, and also availably discharged at any point along belt through plough type unloader or mobile unloading vehicle.

Summary of common fault and treatment: common belt convey is consist of conveying belt, roller, expansion cylinder, driving, braking, tensioning, modification, loading, unloading and cleaning device.

One, the most common fault: belt conveyor is running deviation.

Point to solve such fault is to keep installation size precision and routine maintenance. There is a variety of reasons for deviation, we should adopt different treatments to the different causes.

First, adjust the carrying idlers if belt deviates in central roller position; and make mounting hole on both sides long. Specific adjustment method is move roller group inversely forward with belt deflection, but what should attention is that if belt deviates forward, lower roller group should move to the left, or the upper roller group moves to the right.

Second, install self-aligning roller group .There are many types of self-aligning roller group such as intermediate shaft type, four connecting rod type, vertical roll type. Its principle is rotating barrier or the roller in the horizontal direction to resist or produce transverse thrust to impel belt of automatic centripetal movement. Generally, the method is reasonable for conveyor belt of short total length or of bidirectional operation, the reason is that a shorter belt conveyor is easier-deviation and hard-to-adjust. Or, the self-aligning idlers may influence long belt usage life.

Third, adjust cylinders and redirect its position, which is an important link of belt deviation adjustment. Because a belt conveyor has at least 2 to 5 cylinders, and they must be perpendicular to the center line, or it would cause deviation if the divergence is too large. The adjusting method is similar for roller group’s. As for the head drum, a right forward movement is for right deviation, a left forward movement is for left deviation. A tail adjustment method is opposite to the head. In addition, it’s better to accurately install drum before adjustment.

Fourth, adjust the tensioning belt. The two upper drum of heavy hammer should be perpendicular to the direction of belt length and the vertical, which namely ensure the shaft center line level. In using spiral tensioning or hydraulic tensioner, two bearing seats of tensioner cylinder shall be translated simultaneously to ensure the cylinder axis is perpendicular to the longitudinal direction of the belt. Concrete method is similar to the cylinder’s.

Fifth, feeding point in transfer position impact greatly on deviation, especially when the two belt machines project vertically. Then, we should consider relative height of the two belt machines. The lower of relative height is, the larger of the material horizontal velocity, so is the impact on the lower belt, simultaneously the material is also very difficult to center. If the material is partial to the right, then the belt deviates to the left, and vice versa. So in the design process we should increase the relative height of two belt machines as much as possible. Seriously consider about form and size of upper and lower funnel, guide chute etc. in the limited space of the mobile bulk material conveying machinery. General width of guide chute should be 2/3 of the belt’s. In order to reduce or avoid the deviation of the belt can increase the baffle plate barrier material and change the material dropping direction and position.

Sixth, adjust two-way running belt deviation. This deviation adjustment is further harder than the one-way belt conveyor deviation. In particular adjustment, we should adjust a certain direction, and then adjust the other one. Besides, we should carefully observe relationships between the belt moving direction and the deviation trend, individually adjust them. Emphasis should be placed on adjustment to the driving drum and redirection drum, followed by the roller adjustment and material dropping point adjustment. It should be noted that the belt in the vulcanization joints shall enable the belt section of stress uniform, so is the chain traction on both sides of the force.

The treatment of material scattering

Conveyor belt material scattering is a common problem, reason is also different. But the key is to strengthen the routine maintenance.

First, material scattering in transfer point mainly drops in the hopper or the guide chute, etc. As the belt conveyor seriously overload, a guide chute blocking rubber apron will be damaged, which makes material out of the guide chute. The situation can be resolved in control of the transport capacity and strengthen maintenance.

Second, material scattering of concave section hanging. When the concave curvature radius is small, belt will be suspended, and then belt chute conditions are changed. Therefore, in the design phase, we should use larger concave curvature radius to avoid such situations. For example, design an arc transition interval in the mobile machinery loader, stacker reclaimer equipment in order to shorten the tail car, when the belt width redundancy is small,scattering is easier to occur.

Third, material scattering in deviation: scattering here is for the changeable height of two edge in running, and the processing method is to adjust the belt deviation.