Spray gun and method for reducing rebound rate of wet-process sprayed concrete

Abstract

The invention belongs to the field of mine anchor spraying, and relates to a spray gun and method for reducing the rebound rate of wet-process sprayed concrete. The spray gun comprises a high negative pressure cavity, a diffusion cavity, a spraying material flow guide device and a rubber spray pipe which are coaxially and sequentially communicated; a compressed air inlet formed in the high negative pressure cavity and the high negative pressure cavity are coaxially arranged, a high negative pressure nozzle facing the diffusion cavity is arranged at the tail end of the compressed air inlet, and an included angle of 45-90 degrees is formed between a wet-process sprayed concrete inlet and the compressed air inlet, and an included angle of 45-90 degrees is formed between a wet-process sprayed concrete water inlet and the compressed air inlet; and one or more rows of gas spray holes or strip seams are formed between an inner cavity and an outer cavity of the spraying material flow guide device, and the gas spray holes or strip seams are annularly formed in the axial direction of the spraying material flow guide device at the included angle of 30-45 degrees. After the wet-process sprayed concrete and water are injected into the spray gun by high negative pressure gas, the rebound rate of the sprayed concrete is greatly reduced after diffusion-collision type mixing, shrinkage-collision type mixing, diffusion-collision type mixing and shrinkage-collision type mixing are sequentially carried out, a high-quality sprayed face close to wet-process spraying is obtained, and dust hazards are greatly reduced.

Description

technical field [0001] The invention belongs to the field of anchor spraying in mines, and relates to a spray gun and a method for reducing the rebound rate of tidal shotcrete. Background technique [0002] At present, in the concrete spraying construction of anchor spraying surface in the mine, there are two types of wet method and wet method; Spray gun, and then complete the spraying operation of the surface to be sprayed. The advantages of wet spraying are low rebound rate, less dust production, and good spraying construction quality; its disadvantages are that the equipment used is expensive, and in order to prevent the slurry from solidifying in the feeding mechanism, the operation and equipment maintenance are very complicated. The tidal method is to mix cement, sand, stones and water in a small proportion to form a tidal spray material, and then use a tidal concrete sprayer to send it to the spray gun; the tidal spray material is mixed with the water in the spray gun...

AI Technical Summary

Problems solved by technology

This water supply method and design method make the water spray hole or ring seam easily blocked by the material, resulting in uneven mixing of tidal material and water, and even separation of water and tidal material, resulting in insufficient wetting of the tidal material, resulting in sprayed concrete return. The elastic rate is as high as 40-50%, which not only wastes materials, but also produces a lot of dust, which brings serious occupational hazards to operators.

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