A gas injection device with retreating gas injection point in an underground gasification system

Abstract

The invention discloses a gas injection point retreating type gas injection device used in an underground gasification system. The gas injection device comprises gasifying agent delivery pipes respectively sleeved with sleeves; each sleeve is provided with at least one hole; one-way stop valves, slurry injection ports and gas injection ports are arranged on the parts of gasifying agent delivery pipes inside the sleeves; the slurry injection ports extend outwards to form slurry injection pipes; guiding holes are formed in the side walls of the slurry injection pipes; the gas injection ports are equipped with opening devices; each opening device comprises a sealing cover, a supporting rod, a one-way plug and a dragrope. According to the gas injection device provided by the invention, a rear gas injection point can be opened automatically while the slurry injection operation is started, and the rear gas injection point is opened without the aid of manual operation and control, thus providing great convenience for working personnel. Slurry injected in the gasifying agent delivery pipes is prevented from cracking, and a gasifying agent is prevented from flowing to the front gasified area through the one-way valves and cracks of the slurry.

Description

technical field [0001] The invention relates to the field of underground coal gasification production, in particular to a gas injection device with a retreating gas injection point in an underground gasification system. Background technique [0002] Due to the existence of a large amount of coal resources that cannot be mined artificially or are uneconomical by artificial mining, people have long begun to conduct research on coal gasification technology. The Chinese patent with publication number CN1298058A "An underground gasification system for producing coal gas in mines" Furnace", its structure lacks the gas injection control of the gas injection pipe in the coal seam, so there are insufficient coal seam combustion and low coal utilization rate; the Chinese patent of publication number CN1112188A "Pipe-drawing gas injection point retreat type coal seam gasification method" Use the fusing method to melt the gas injection pipe mouth section by section to realize the gas in...

AI Technical Summary

Problems solved by technology

This system uses the method of grouting to landfill the burned channel, cut off the gasification agent and continue to supply gas to the burned channel, however, the system cannot automatically start the subsequent injection while starting the grouting operation. The gas point must be opened by manual control to open the gas injection point, which brings great inconvenience to the staff

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