Underground coal shotcrete machine, also known as concrete shotcrete machine, is an equipment used for dry shotcreting and wet shotcreting. It has the characteristics of advanced technology, reasonable structure, stable performance, convenient operation and maintenance, and long service life. It is widely used in mines, tunnels, culverts, subways, slope support, hydropower projects, underground projects and mine roadways sprayed concrete construction operations.
Dry shotcrete machine for underground coal is mainly composed of driving device, rotor assembly, air duct system, injection system, electrical control box and other parts. The agitated material first enters the jet hopper through the vibrating screen, and is moved by the shifter or injected into the straight-through cavity of the rotor by wind pressure, and then goes to the outlet with the rotor. Compressed air entering from the air chamber, Blow the material into the discharge elbow; the cyclone introduces another pressure air, which is a multi-head spiral wind beam to blow the material, accelerate, rotate and float, enter the conveying pipe, and reach the nozzle. Add a small amount of supplementary water (when spraying wet) or liquid quick-setting agent (when spraying wet) to spray out. The product advantages of dry shotcrete machine for coal mine are as follows:
1. Straight-through rotor type non-adhesive material cavity, unobstructed discharge, high efficiency and time saving, reducing cleaning and maintenance workload.
2. Four-point elastic compensation and compression, good sealing effect, less dust around the machine, and long service life of wearing parts.
3. Low-pressure and high-speed vortex air conveying can overcome the problems of adhesion, pipe blockage and pulse separation in material conveying, and the material flow is uniform, continuous and stable.
4. The nozzle is made of high polymer material by pressure injection, which improves the spraying effect, with high spray layer quality and less rebound.
5. The accessories required for the equipment are all produced by our company, with high wear resistance/high alloy material, strong wear resistance, long service life, economical and durable. Spray operation method of dry shotcrete machine for underground coal:
After the preparation work is completed, the mixing material can be added to the machine. The operator should first open the main valve, open the valve of the upper air pipe 1/3 turn, and then adjust the lower air pipe (air pressure to the cyclone) to approximately 0.05-0.1Mpa no-load wind pressure (depending on the conveying distance). Then turn on the nozzle water valve to wet the surface of the rock mass. At this time, the machine operator can start the machine and start the concrete spraying operation. The current working pressure is about 0.2-0.4Mpa. According to the water-cement ratio of the mixture and the conveying distance, adjust the wind pressure to the cyclone until the sprayer thinks that the jet velocity is appropriate. After the adjustment of the lower air pipe valve is confirmed, open the upper air pipe valve again until there is no more material leakage from the remaining air port of the machine.