1 Summary of belt conveyor in coal mine
1.1 Working principle of belt conveyor
The conveyor belt is connected into a closed loop, tensioned by a tensioning device, and driven by an electric motor, running continuously through the friction between the conveyor belt and the driving wheel, to transport coal from the loading end to the unloading end.
1.2 Structure of belt conveyor
Take the drum belt conveyor as an example, the main parts of the belt conveyor are: conveyor belt, bracket, frame, transmission device, tensioning device, belt storage device, cleaning device.
1.2.1 Conveyor belt
Conveyor belt is not only a bearing mechanism, but also a traction mechanism. Transmission with many kinds, according to the core material structure is divided into wire rope conveyor belt, nylon core conveyor belt, cotton core conveyor belt and canvas core conveyor belt; According to different flame retardant properties, it can be divided into non-flame retardant belt and flame retardant belt.
1.2.2 Idlers and racks
The roller is used to support the conveyor belt to reduce the running resistance of the conveyor belt, so that the overhang of the conveyor belt does not exceed a certain limit, and ensure the smooth operation of the conveyor belt. The supporting wheel is composed of shaft, bearing and standard sleeve. According to the use of idlers, it can be divided into groove idlers, flat idlers, alighting idlers and buffer idlers.
1.2.3 Driving device
The driving device is the power source of belt conveyor. The drive is driven by single motor and multiple motor, the motor drives the drum through the hydraulic coupling and reducer.
1.2.4 Tension device
The function of the tensioning device is to ensure that the conveying with enough tension, so that the necessary friction between the roller and the conveyor belt; The second is to limit the conveyor belt hanging between rollers to ensure the normal operation of the conveyor belt. Tensioning device is mainly divided into mechanical tensioning device, electrical tensioning device and hydraulic tensioning device.
1.2.5 Belt storage device
Belt storage device is used to store the redundant belt before and after the telescopic belt conveyor to meet the needs of continuous advance and retreat of the working face.
1.2.6 Brake device
When the belt conveyor is transported upward in the roadway with an average inclination Angle greater than 4 degrees, brakes should be installed to prevent the conveyor belt from reversing under the action of load after the conveyor stops running. Such as belt brake, disc brake, electro-hydraulic brake, hydraulic disc brake and so on.
Read more: how to repair the broken belt
2. Common faults of coal mine belt conveyor
The common faults of coal mine belt conveyor mainly include belt fault, damage fault and abnormal operation of parts. Belt is the most common type in the use of coal mine belt conveyor, including belt deviation, belt slipping. Tape breakage, tape noise, etc. Damage faults often occur in parts of the roller and roller, and abnormal operation faults mainly occur in the reducer.
2.1 Tape deviation fault
Generally speaking, the belt deviation fault of the coal mine belt conveyor may be due to the problems existing in the process of equipment installation, such as the connection between the belt interface and the unbalanced force in the middle or on the belt due to the imbalance on the coal belt, resulting in the belt displacement.
2.2 Rubber belt slip fault
The main reasons are as follows: first, the conveyor belt tension is insufficient; The second is excessive dust accumulation of mechanical equipment; The third is the lack of maintenance of the corresponding equipment and the replacement of old parts, so that the conveyor belt of the belt conveyor is not smooth enough.
2.3 Tape fracture fault
The belt fracture of coal mine belt conveyor usually occurs suddenly. The main reason for the belt fracture is that the belt conveyor has been working continuously for a long time, the belt is seriously worn, the wire rope in the belt conveyor is corroded, the belt is suddenly blocked by a large number of objects and stuck operation, and the pressure on the belt is suddenly increased.
2.4 Noise faults
Fault judgment of belt conveyor running noise is one of the important indexes to judge the operation of belt conveyor. Under normal operating conditions, the conveyor belt is very quiet. If the operating sound is significantly increased, it can be divided into noise or obvious beeps, which means that the equipment may have abnormalities, such as bearing damage, abnormal coupling, roller off-center, increasing bearing wear.
2.5 Damage Faults
In the running process of belt conveyor, the components that often appear damage are roller and idler. Roller damage mainly includes welding joint surface cracking, cracking of any side of the cover and vulcanized plastic damage, the main failure of the roller is unqualified quality.
2.6 Component Running Exception Faults
Reducer and other parts appear many abnormal operation faults, such as: reducer easy to mix with metal impurities, affect the load, coal dust and other factors make reducer abnormal operation, bearing damage or clearance is too large.
3 Measures to solve the fault of belt conveyor in coal mine
3.1 Measures for belt deviation
Belt deviation phenomenon, first of all, the equipment with the help of the steering roller, can ensure that the running process of the belt conveyor is always in a stable state, but also to ensure that the installation position is horizontal, that is, the rotating direction of the belt is consistent, and always keep vertical with the axis of the steering mix, in order to achieve the desired effect. In addition, in order to ensure that the joint of the conveyor belt joint is straight, the straightness tolerance value of the length greater than 10m should be controlled within 20mm. Again, in order to prevent the conveyor belt joint deformation, enhance the quality control of the joint, in order to prevent the belt running deviation, because the device set of supporting roller wear faster, lead to the phenomenon of poor contact on the tape, cause the belt running deviation, which requires technical personnel related equipment should be inspected regularly, and for bearing rollers timely adjustment or replacement. Finally, strengthen the daily maintenance of the belt conveyor.
3.2 Skid treatment
Adjust tension equipment, increase initial tension, reduce the load of belt conveyor in transportation,and improve motor capacity. Check the adhesive tape regularly, vulcanize the aging or deformed parts of the adhesive tape again, and finally clean the floating dust on the roller regularly.
3.3 Belt breaking treatment
Adjust the belt tension in time to ensure that the belt tension is moderate. Remove improper belt connector and reconnect. The larger materials are strictly glued on the conveyor belt to avoid continuous overload.
3.4 Noise Treatment
The noise of coal mine belt conveyor is a universal problem. Mainly from bearing fracture and produce some noise. In order to solve the noise problem effectively, the position deviation should be prevented when the belt conveyor is installed. Secondly, the damaged bearings are replaced in time and lubricated. Finally, it is needed to check whether the bite force between bearings is up to standard.
3.5 Troubleshooting Measures for Damage Faults
The main reason for the damage is that the routine maintenance work is not in place and the staff do not fully understand the status of the belt conveyor. There are two ways to prevent damage: on the one hand, choose parts that meet the quality requirements of the standard; The damaged roller and idler is an important part of the bearing and bracket of the belt conveyor, so it is necessary to choose the parts with strong bearing capacity. On the other hand, we should pay more attention to the maintenance of the conveyor, establish specialized maintenance organizations and personnel, establish a perfect maintenance system, increase the daily inspection, in order to find out the abnormal problems of the conveyor parts, timely replacement of wear and aging parts to reduce the possibility of parts damage.
4 Conclusion
To sum up, in the whole coal mine production system, the transport operation completed by the belt conveyor is the key link. With the improvement of coal mine operation mechanization level, belt conveyor will play a more and more important role. Therefore, in order to ensure normal production, smooth operation and improve production efficiency, the relevant personnel should find out the fault belt conveyor in time and accurately, and solve the problem with the correct method. At the same time, to strengthen the belt conveyor maintenance, better service in coal production.
