A gas-liquid spray dust settlement system for a fully mechanized mining face includes an atomization humidification subsystem, a boundary mist curtain subsystem, and a dust mist recycling subsystem that are all arranged outside the fully mechanized mining face, where the boundary mist curtain subsystem includes high-pressure blade nozzles mounted to hydraulic supports. The atomization humidification subsystem includes a spray dust settler mounted to a rocker arm of a coal cutter and configured to spray water mist completely covering the high-pressure blade nozzle. The dust mist recycling subsystem includes a wind-water linkage dust remover mounted to a semi-encircling support base, arranged under the spray dust settler, and configured to collect the water mist sprayed by the spray dust settler.

A gas-liquid spray dust settlement system for a fully mechanized mining face includes an atomization humidification subsystem, a boundary mist curtain subsystem, and a dust mist recycling subsystem that are all arranged outside the fully mechanized mining face, where the boundary mist curtain subsystem includes high-pressure blade nozzles mounted to hydraulic supports. The atomization humidification subsystem includes a spray dust settler mounted to a rocker arm of a coal cutter and configured to spray water mist completely covering the high-pressure blade nozzle. The dust mist recycling subsystem includes a wind-water linkage dust remover mounted to a semi-encircling support base, arranged under the spray dust settler, and configured to collect the water mist sprayed by the spray dust settler.

A filter assembly includes a first screen, defining a first flow passageway, a second screen, defining a second flow passageway, and a third screen defining a third flow passageway. The second screen is positioned between the first screen and the third screen. The first flow passageway is aligned with the third flow passageway and the second flow passageway is offset from the first flow passageway and the third flow passageway.

Provided are a drill-power-based directional hydraulic fracturing system for downhole quick slotting and a method thereof. The directional hydraulic fracturing system includes a water injection pump, a high pressure rubber pipe arranged on the water injection pump is in communication with a drill, a dedicated sealing drill rod for hydraulic fracturing is arranged on the drill, a front segment of the drill rod may be connected with a directional borehole sealer through threads and a sealing ring is provided at the threaded connection. The main steps include drilling, slotting, borehole sealing and fracturing. Firstly, a drill-cut integrated tool is installed at a front end of the drill rod. After drilling is completed, hydraulic slotting, permeability improvement and pressure relief are performed without changing a drill bit. After slotting is completed, the drill bit is retreated, and the directional borehole sealer is installed and pushed to a predetermined position for efficiency sealing. After sealing is completed, high pressure water injection fracturing is performed to increase fissure density and scope with high pressure penetration as main. Thus, water injection for the coal seam with high ground pressure and low porosity is realized. In this way, coal bumps are effectively prevented, the powder dust concentration is reduced and the disasters such as gas and fire are prevented.

To allow removal or replacement of mining equipment from a tunnel without unduly limiting the size of the mining equipment or without an unduly excessive cross-section of the tunnel, the mobile unit includes a conveying system having a first and a second transfer area, and a dust extraction system. The conveying system receives mined material in the first transfer area, conveys the received mined material to the second transfer area and dispenses the received and conveyed mined material at the second transfer area. The dust extraction system receives dust-laden air, extracts dust from the dust-laden air and discharges air from which dust is extracted. The mobile unit includes a first and/or a second dust collector for collecting dust-laden air from the first and/or second transfer area, respectively, with the first and/or second dust collector being arranged to supply the collected dust-laden air to the dust extraction system for dust extraction.

To allow removal or replacement of mining equipment from a tunnel without unduly limiting the size of the mining equipment or without an unduly excessive cross-section of the tunnel, the mobile unit includes a conveying system having a first and a second transfer area, and a dust extraction system. The conveying system receives mined material in the first transfer area, conveys the received mined material to the second transfer area and dispenses the received and conveyed mined material at the second transfer area. The dust extraction system receives dust-laden air, extracts dust from the dust-laden air and discharges air from which dust is extracted. The mobile unit includes a first and/or a second dust collector for collecting dust-laden air from the first and/or second transfer area, respectively, with the first and/or second dust collector being arranged to supply the collected dust-laden air to the dust extraction system for dust extraction.

A mining machine includes a chassis, a cutting assembly coupled to the chassis, and a spray arm coupled to the chassis and positioned proximate the cutting assembly. The chassis includes a first end, a second end, and a chassis axis extending between the first end and the second end. The chassis is movable in a direction parallel to the chassis axis. The cutting assembly includes an arm and a rotatable cutting drum having a plurality of cutting elements. The spray arm includes a first portion, a second portion pivotably coupled to the first portion, and at least one spray nozzle for emitting a fluid spray in a region adjacent the cutting assembly. The first portion is coupled to the chassis and extends away from the chassis along a spray arm axis. The second portion is pivotable relative to the first portion about a wrist axis.

A mining machine includes a chassis, a cutting assembly coupled to the chassis, and a spray arm coupled to the chassis and positioned proximate the cutting assembly. The chassis includes a first end, a second end, and a chassis axis extending between the first end and the second end. The chassis is movable in a direction parallel to the chassis axis. The cutting assembly includes an arm and a rotatable cutting drum having a plurality of cutting elements. The spray arm includes a first portion, a second portion pivotably coupled to the first portion, and at least one spray nozzle for emitting a fluid spray in a region adjacent the cutting assembly. The first portion is coupled to the chassis and extends away from the chassis along a spray arm axis. The second portion is pivotable relative to the first portion about a wrist axis.

Systems and methods for controlling dust. One method includes automatically detecting an operating status of a mining machine. The method also includes automatically, with an electronic processor, adjusting operation of a dust suppression system based on the operating status of the mining machine.

A cutting bit assembly includes a block, a bit sleeve, and a seal. The block includes a first bore and a fluid passage. The fluid passage includes a first portion and a second portion in fluid communication with the first portion. The first portion is oriented obliquely with respect to the first bore, and the second portion extends at least partially around the perimeter of the first bore. The bit sleeve includes a shank, a flange, and a second bore extending through the shank and the flange. The shank is positioned within the first bore of the block such that a surface of the flange engages a first end surface of the block. The seal is positioned between the second portion of the fluid passage and the shank to prevent contact between a fluid in the fluid passage and the outer surface of the shank.