Most of the domestic coal belt conveyor
are generally used frequency drag, less use of inverter drive. As the motor long-term frequency operation coupled with the efficiency of the hydraulic coupler and other issues, resulting in belt conveyor is very uneconomical to run; the same time because the motor can not use soft soft stop, in the mechanical impact, accelerate the mechanical wear; Hydraulic coupler wear and maintenance and other issues will give enterprises a lot of the cost of the problem. This is not suitable for the creation of energy-saving society now, the coal mine belt conveyor
belt transformation to save social energy, increase the economic benefits of coal mining enterprises have a very realistic economic significance and social significance. The structure of the belt conveyor is composed of 400 meters of coal mine in North China. The first stage is transported downwards, the horizontal distance is 950 meters and the height is 116.3 meters. The second section is transported downwards, the horizontal distance 680 meters, lifting height of 25 meters; the third paragraph down transport, the distance of 630 meters, lifting height of 84.2 meters. Transport capacity of 3,000 tons / hour (maximum), belt bandwidth of 1.4 meters, the belt machine running speed of 4m / s, transport mode for the transport. Before the transformation of the way for the transfer of each belt from the two 660V, 250KW Rao line three-phase asynchronous motor by hydraulic coupler coaxial connection; belt machine start and run mode, the winding motor by the rotor winding buck After the start of the frequency of operation, the hydraulic coupler to switch to the belt machine.
The motor of the first and second belt machines is powered by two transformers of the same line, and the motor of the third belt conveyor
is powered by another transformer of the same line. Before the transformation of the belt belt machine into the system, do not contact each other, are used manual mode of operation, the belt machine after the start of the motor constant speed operation, the use of hydraulic coupling to adjust the mechanical efficiency to adjust the speed of the belt. The working principle and characteristics of the belt machine belt drive through the drum drum, by friction traction belt movement, the belt through the tension deformation and friction to drive the object in the support roller movement. Belt is a flexible energy storage material, in the belt machine to stop and run a large number of potential energy stored, which determines the start of the belt machine should be used soft start mode. Most of the domestic coal mine hydraulic coupler to achieve the soft start of the belt, when the hydraulic coupling to adjust the mechanical efficiency of zero, so that the motor no-load start. Although the use of the rotor series resistance to improve the starting torque and buck no-load start and other methods, but the motor starting current is still large, not only will cause the power grid voltage fluctuations, but also cause the motor internal mechanical shock and heat and so on. At the same time the use of hydraulic coupler soft leather belt, due to the short start-up time, the loading force is likely to cause the belt to break and aging, requiring high strength belt. Coupled with the hydraulic coupling from a long time will cause its internal oil temperature rise, metal parts wear, leakage and efficiency fluctuations, etc., will not only increase the difficulty and cost of maintenance, pollution of the environment, but also make multi-machine drive the same belt It is difficult to solve the power average and synchronization problems.
Belt machine frequency transformation, the original electrical cabinet as a power frequency bypass, while the hydraulic coupler to maximize the efficiency; if the debugging inverter failure, you can use the original power frequency start cabinet emergency Operation, start the hydraulic coupler to adjust the efficiency of zero, the motor no load start, after the appropriate adjustment of hydraulic coupler efficiency. When the operation of the entire equipment is completed, the experimental operation for some time to prove that the overall operation of the device is stable, good, you can remove the hydraulic coupler, the belt shaft directly connected to the motor. Remove the hydraulic coupler storage reserve, if the inverter failure requires frequency operation, you can put the corresponding hydraulic coupler to install the emergency operation. After the transformation of the technology after the belt conveyor is running well, the realization of the belt conveyor soft start, soft stop running mode, greatly improving the system power factor and system efficiency.
After the transformation, the system can automatically adjust the output frequency and output torque according to the load change, change the mode of the constant operation of the motor power frequency, and save the power energy to a great extent; and the use of the four-quadrant high voltage inverter The energy feedback function further reduces the energy consumption of the belt machine; the withdrawal of the hydraulic coupler saves the maintenance and maintenance costs of the equipment. After the transformation of the operation, it turns out that the domestic Kits series of high-voltage inverter with many domestic and foreign transitional high voltage inverter products, compared with the superior product performance and can not go beyond the technological leading edge in the coal industry energy saving The application of transformation can create huge economic benefits and good social benefits, for the creation of energy-saving environment-friendly society plays an important role.