A nitrogen low temperature positive pressure long-distance rapid gas content sampling device and method

Abstract

The present invention relates to the technical field of coal seam drilling and sampling, in particular to a nitrogen low-temperature positive pressure long-distance rapid gas content sampling device, in which the drill pipe passes through two corresponding horizontal passages of the variable-diameter spool and the front end goes deep into a spud In the hole, another horizontal channel in the variable diameter cross is slidingly sealed with the outer wall of the drill pipe, the lower channel of the variable diameter cross is connected to the slag collection assembly in a sealed manner, and the upper channel of the variable diameter cross is used to drain the hose One is connected to the main pipe for pumping; there is a channel for delivering nitrogen inside the drill pipe, and the tail of the drill pipe is connected to the output end of the temperature-controlled nitrogen mixing box through a mixed nitrogen hose. The input end of the temperature-controlled nitrogen mixing box consists of two, one of which is The input end is connected with the nitrogen pipeline, and the other input end is connected with the liquid nitrogen bottle. The device can actively discharge slag, reduce the temperature of the coal sample, avoid the oxidation of the coal sample, reduce the gas loss, and at the same time, the slag discharge capacity can fully meet the long-distance sampling.

Description

technical field [0001] The invention relates to the technical field of coal seam drilling and sampling, in particular to a nitrogen low temperature positive pressure long-distance rapid gas content sampling device and method. Background technique [0002] Accurate measurement of coal seam gas content is the basis of coal mine gas control and a key parameter related to coal mine safety production. However, there is no uniform sampling method for gas content at present. At present, the gas content measurement and sampling methods in underground coal seams in coal mines mainly include auger drill cuttings sampling method, positive pressure air blowing coal cuttings sampling method, negative pressure extraction drilling cuttings sampling method, coring device single cylinder coring method, and liquid nitrogen low temperature sampling method. The temperature, pressure, particle size, and sampling position of the coal sample have an important impact on the desorption results of th...

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Problems solved by technology

[0002] Accurate measurement of coal seam gas content is the basis of coal mine gas control and a key parameter related to coal mine safety production. However, there is currently no unified gas content sampling method

At present, the gas content measurement and sampling methods in underground coal seams in coal mines mainly include auger drill cuttings sampling method, positive pressure air blowing coal cuttings sampling method, negative pressure extraction drilling cuttings sampling method, coring device single cylinder coring method, and liquid nitrogen low temperature sampling method. The temperature, pressure, particle size, and sampling position of the coal sample have an important impact on the desorption results of the gas content. The auger drill cuttings sampling method has short construction distances and inaccurate coal sample collection positions. and other problems; the compressed air medium of the positive pressure coal chip sampling method is air, and its sampling speed is fast, but it is easy to cause coal sample oxidation, coal body temperature rise, and large coal dust in the working environment; negative pressure extraction type The drilling cuttings sampling method has a fast sampling speed, but the coal sample transportation channel is narrow and easy to block, and the applicability is poor, and the transportation capacity of negative pressure is far lower than that of positive pressure, which is not suitable for long-distance sampling; When the coal sample cooling medium exists, the coring cylinder and the coal body will rub against each other to generate heat, and the temperature of the coal sample will rise sharply, causing a large amount of gas to escape, and the coring time will be long, and the gas loss will be large; the liquid nitrogen low temperature coring device The coring method is based on the single-cylinder coring method, and a liquid nitrogen cryogenic device is installed in the coring device, which overcomes the frictional heat generation problem of the coring device and enables the coal sample to be kept at low temperature, but the sampling time is long and the sampling process is complicated , a large amount of gas loss

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