(1) Fixed high-strength belt conveyor
This is currently the most widely used model in coal mines underground, mainly used in horizontal or inclined situations less than 18 degrees. Due to the limitations of the strength of the conveyor belt and components, the length of a single machine cannot be too long. The highest steel wire core belt in China is ST4000, and the whole core belt is PVG3150S. High-strength mechanical joints rely on imports. To reduce the strength of the belt and decrease the size of the drive device, both domestic and foreign commonly use intermediate linear friction drive and intermediate unloading drive, and employ soft start technology. There are nearly 10 types of soft start methods available domestically, which effectively solve the starting problems of large conveyors. Currently, the maximum main parameters of conveyors used underground in China are: capacity Q=1000~3000t/h, transport distance L=1000~5000m, belt speed V=2.5~4.5m/s, total drive power N=750~2000kW, and inclination has reached 30 degrees. The main parameters of foreign belt conveyors are: transport distance L=30.4km, capacity Q=37500t/h, belt speed V=6~15 m/s, and belt width B=4 m.
(2) Telescopic belt conveyor
This model is mainly used for transporting raw coal in the working face of coal mines. When the transport capacity and distance are large, an intermediate drive device can be added to meet the requirements. Some manufacturers in the United States, Germany, the United Kingdom, and other countries can provide telescopic belt conveyors suitable for various production scales in high-yield and efficient working faces, with main parameters: capacity Q=2000t/h, transport distance L=5000m, belt speed v=3.5~4m/s, total drive power N=2400kW. The key research project "High-yield and Efficient Working Face Telescopic Belt Conveyor" from the 1998 "Ninth Five-Year Plan" can meet the needs of domestic high-yield and efficient working faces with an annual output of 2 million tons, with main parameters: capacity Q=1600~2000 t/h, transport distance L=2500m, belt speed B=3.5~4m/s, total installed power N=1200kW, belt width B=1.2m, and transport inclination B≤1°. In 2001, industrial trials were completed, and in January of the same year, it passed the technical appraisal of the China Coal Industry Association. This year, a telescopic belt conveyor for a high-yield and efficient working face with an annual output of 8 million tons was successfully developed, with main parameters: capacity Q=2500t/h, transport distance L=3000m, belt speed V=3.5 m/s, belt width B=1400m, transport inclination B≤3°, power N=3x375kW, whole core belt PVG1800S, equipped with a storage belt warehouse, and the tail of the machine can extend or shorten with the advancement of the coal mining working face. The structure is compact, can be laid directly on the floor of the tunnel without a foundation, or can be suspended from the roof of the tunnel. The frame is lightweight and easy to disassemble. The conveyor belt generally uses a whole core belt, connected with mechanical joints, and is basically consistent with the main parameters of a telescopic belt conveyor introduced from ACE Company by the Shanxi Jincheng Mining Bureau.
