54results about How to "Guaranteed Diffusion Effect" patented technology

The present invention relates to a U-shaped ventilation working face goaf full-face curtain nitrogen injection fire preventing and extinguishing method comprising determining the nitrogen flow rate QN of a main pipeline, and is characterized in that the laying number of nitrogen injection pipes n0=int(Ly / Lb+1). When n0=3, the method comprising steps of (1) laying the first nitrogen injection pipe full face along an inner side of a rear chute at the rear portion of a support, propelling to a position away from a goaf boundary with an LK distance in the working face propelling direction along a coal face, performing leaking stoppage on upper and lower ends, and enabling a control valve of the nitrogen injection pipe to continuously inject nitrogen to the goaf full face; (2) propelling to a position where a distance between two nitrogen injection pipes is goaf nitrogen injection pipeline array pitch Lb along the coal face, repeating the method (1) to lay the next nitrogen injection pipe, and achieving nitrogen injection of the next nitrogen injection pipe; and (3) repeating the method (2) to achieve continuous nitrogen injection to the goaf full face by the third nitrogen injection pipe. A continuous nitrogen curtain is formed at the whole goaf by nitrogen injection, residual coal low-temperature oxidation is suppressed, nitrogen is prevented from rushing into the coal face, the nitrogen diffusion radius is fully utilized, and the nitrogen diffusion effect and nitrogen inerting efficiency are improved.