34results about How to "Prevent roof fall" patented technology

The invention relates to a super large mining height hydraulic support which comprises an opened rigid integrated base, wherein, two double-telescopic hydraulic upright posts are arranged on the base, and the upper ends of the upright posts are connected with a top beam; the rear of the top beam is connected with a screening beam; an edge protection device is connected with the telescopic beams which are in inner extension connection with the top beam; a balance jack is arranged between the top beam and the screening beam; the screening beam and the base are respectively connected with the front and rear connecting rods; a push jack is arranged on the base and is connected with a push rod; the front part of the top beam is provided with the telescopic beams, the middle part of the top beam is provided with a falling prevention device for the support, and bottom lifting, skid prevention and support regulation devices are arranged on the base; and a levelling device is arranged on a cross binding head on the front end of the push rod; the support adopts 2-meter width between centers, the maximum height ranges from 6.3 meters to 7.5 meters, and the front end of the telescopic beam is provided with a third-stage edge protection device which is not lower than half of the mining height. The support has obvious effects of controlling the wall caving of the coal wall of a super thick coalseam, the roof fall of the ceiling, and the stability of the hydraulic support.

The invention relates to a chemical grouting material for reinforcing loose and broken bedrock. The invention provides a chemical grouting material for reinforcing the loose and broken bedrock, in order to improve the flash point, the burning point and the antistatic performance of the grouting material, reducing the temperature in polymerization reaction and lowering the cost. According to the technical scheme provided by the invention, the chemical grouting material for reinforcing the loose and broken bedrock comprises two components, including a component A and a component B; according to the formulas of the raw materials, the component A comprises 90 to 100 parts by weight of sodium silicate or potassium metasilicate solution, 0 to 5 parts by weight of surface active agent, and 0 to 5 parts by weight of accelerator; the component B comprises 70 to 90 parts by weight of isocyanate, 5 to 20 parts by weight of plasticizer, 0.5 to 3 parts by weight of polyalkane silicone, and 0 to 5 parts by weight of catalyst; the components A and B are uniformly mixed respectively; and in use, the components A and B are mixed according to the volume ratio of 1: 1. The chemical grouting material can be applied to quickly reinforcing the broken coal bed and rock bed and blocking water leakage.

The invention discloses a four-leg shield-type sublevel caving hydraulic support, which comprises four supporting hydraulic extension legs equipped on a pedestal. The top ends of the four supporting hydraulic extension legs are respectively hinged with a top beam; a forward extension beam is hinged at the front end of the top beam; a sprag is hinged at the front end of the forward extension beam, a sprag lifting jack is equipped on the forward extension beam, an ejector rod of the sprag lifting jack is hinged with the back part of the sprag; the back part of the top beam is hinged with the upper part of a shield beam; the lower part of the shield beam is hinged with the pedestal via the a four-bar linkage mechanism; a tail beam with box-shaped construction is hinged with the lower end of the shield beam, a tail beam lifting jack is equipped between the lower part of the tail beam and the lower part of the shied beam; and a slide track, an inserting plate equipped in the slide track and a inserting plate lifting jack for driving the inserting plate to carry out reciprocating movement along the slide track are equipped in the box of the tail beam. The invention is especially suitable for caving integrated mining working face under pitching coal bed, flat-pitching half hard coal bed and 'three-soft' coal bed conditions.

The invention discloses a supporting method of a super-large section cutting hole of a large-mining-height fully mechanized mining face of a thin base rock. The supporting method comprises the following steps: carrying out primary supporting, wherein the primary supporting comprises first branch supporting and second branch supporting, the first branch supporting is supporting a tunnel by utilizing anchor rods and metal meshes after the cutting hole is tunneled primarily, and the second branch supporting is supporting the tunnel by utilizing anchor rods and a plastic mesh after the cutting hole is expanded secondarily; carrying out primary pressure releasing: after the primary supporting is finished, releasing surrounding rock stress at a moment first pre-set time interval before secondary supporting; carrying out the secondary supporting: after the cutting hole is completely molded, supporting by utilizing an arch rope and a high molecular material for the secondary supporting. According to the supporting method disclosed by the invention, the primary supporting is carried out in a tunneling process of a cutting hole tunnel; after the primary pressure releasing is carried out, the secondary supporting is carried out after the cutting hole tunnel is completely molded, and initiative supporting is carried out by phases; the integrity of a surrounding rock with the cutting hole is maintained, and accidents of roof fall and nicking are effectively prevented from occurring.

The invention discloses a liquid pressure monitoring device and a monitoring method. The whole device is in a cylindrical structure. Upper and lower end covers are arranged at upper and lower parts of the cylinder. Upper and lower end covers contact a middle bearing tube. An inner space formed by the upper and lower end covers and the bearing tube is a bearing cavity. The upper and lower end covers and the bearing tube are in threaded connection. A male straight joint is arranged at the center of the top of the upper end cover, and is connected with a hydraulic support. A circular color-developing material is arranged on the outer side of the bearing tube. A circular reflective material is arranged between the color-developing material and the bearing tube. A circular polarizing plate is arranged on the outer side of the color-developing material. When the device is used for monitoring, the bearing tube is pressed, and the color-developing material produces circumferential tensile stress. Under the irradiation of a headlight, different colors can be clearly distinguished. Through the corresponding relationship between a color-pressure table, the pressure of the hydraulic support can be monitored. According to the invention, the slump of a roof can be effectively predicted to ensure the safe production of a coal mine.

The invention relates to a subcooler for low-temperature liquid oxygen. The subcooler comprises a liquid nitrogen storage tank, a cold exchange assembly, a high liquid level measurement sensor and a low liquid level measurement sensor; the cold exchange assembly is fixed in the liquid nitrogen storage tank through a cold exchange core supporting assembly, and the liquid nitrogen storage tank is provided with a liquid nitrogen inlet, a liquid nitrogen outlet and a nitrogen gas discharge port; the cold exchange assembly comprises a cold exchange core, a liquid oxygen input pipe and a liquid oxygen output pipe, and the liquid oxygen input pipe and the liquid oxygen output pipe are communicated with the cold exchange core; the high liquid level measurement sensor is fixed to the high liquid level of the liquid nitrogen storage tank, and the low liquid level measurement sensor is fixed to the low liquid level of the liquid nitrogen storage tank. According to the invention, the common liquid oxygen with the temperature being minus 183 DEG C can be fast cooled to minus 194 DEG C.

The present invention belongs to the technical field of coal mine coal tunnel digging construction equipment, and particularly relates to a cantilever type longitudinal axis digging and anchoring machine, which comprises a rack body, a left walking part, a right walking part, a cutting part, a rotation body, a rear support body, a loading mechanism, a first scraping plate conveyor, an electric control system, a hydraulic system, a spraying system and a cooling system, wherein the first scraping plate conveyor comprises a machine tail portion arranged on the rack body and a machine head portion extending out of the rack body rear portion, and the machine head portion is provided with a plurality of airborne anchor rod drillers. According to the present invention, during the use, when the cantilever type longitudinal axis digging and anchoring machine digs, the coal tunnel is subjected to anchoring fixation support by using the airborne anchor rod drillers, such that the parallel operations of digging and anchoring can be achieved, the time consumption problem caused by the frequent switching between the two processes such as digging and anchoring can be solved, the construction efficiency and the construction speed can be improved, and the puking phenomenon can be prevented.

The invention discloses a mining technology for a lower slice fully-mechanized coal mining face passing through a concentrated coal pillar of a higher slice coal seam. The mining technology includes the following steps that S001, the position of the concentrated coal pillar is marked in a haulage roadway and a ventilation roadway of a lower slice coal seam; S002, when the lower slice fully-mechanized coal mining face moves forwards to a first preset distance away from the front side face of the coal pillar, observation and statistics of periodic weighting of the lower slice fully-mechanized coal mining face are carried out; S003, by regulating the mining speed of the lower slice fully-mechanized coal mining face, the position of the lower slice fully-mechanized coal mining face is adjusted when periodic weighting occurs; and S004, when the lower slice fully-mechanized coal mining face moves forwards to a second preset distance away from the back side face of the coal pillar, the mining speed of the lower slice fully-mechanized coal mining face is increased, the lower slice fully-mechanized coal mining face rapidly passes through the lower side of the coal pillar, and the time for the lower slice fully-mechanized coal mining face passing through the second preset distance is shorter than the period of periodic weighting. The lower slice fully-mechanized coal mining face can safely pass through the area of the concentrated coal pillar of the higher slice coal seam, roof caving or support crushing is avoided, and the safety of coal production is improved.

The invention discloses a detection device and a detection method for the axial force of an anchor rod. An integrated structure of the device is a regular hexagonal prism; an upper end cover and a lower end cover are respectively connected with a protective shell through fastening screws; a plurality of two-pole U-shaped magnetic cores are uniformly disposed at an outer side of an anchor rod fastening nut; the two-pole U-shaped magnetic cores are located in a space encircled by the upper end cover, the lower end cover and the protective shell; silicon rubber sleeves are sleeved on two magneticpoles of the two-pole U-shaped magnetic cores; a magnetic fluid is filled in each of the silicon rubber sleeves; a circuit slot is disposed in the space encircled by the upper end cover, the lower end cover and the protective shell; a control circuit is disposed in the circuit slot; a wire led from the control circuit passes through the circuit slot to wind an excitation coil and a detection coilto upper and lower ends of the two-pole U-shaped magnetic cores; elastic sheets are disposed at outer sides of the two-pole U-shaped magnetic cores; and the elastic sheets are fixed on an inner wallof the protective shell. The detection device and the detection method for the axial force of the anchor rod are used for detecting the axial force of the anchor rod, the collapse and cave-in of a topplate are avoided, a top plate support parameter is provided, and a reliable technical parameter is provided for support design of a laneway layout and safety monitoring of the top plate.

The invention relates to a blast furnace front dedusting system. The system comprises an ash storage bin, a bin top dust remover, pulse dust collectors, a buried scraper conveyor, a bucket elevator and an ash discharging chamber. Discharge valves are arranged at the lower ends of the pulse dust collectors correspondingly. The buried scraper conveyor is arranged below the discharge valves of the pulse dust collectors. An outlet of the buried scarper conveyor is connected with an inlet of the bucket elevator. An outlet of the bucket elevator is connected with an inlet of the bin top dust remover. An outlet of the bin top dust remover is connected with an ash falling hole of the ash storage bin. The ash discharging chamber is located below a discharge outlet of the ash storage bin. Accordingto the blast furnace front dedusting system, the pulse dust collectors are adopted and matched with the buried scraper conveyor, the bucket elevator, the bin top dust remover and the ash storage bin,the system is made to operate stably, the casting house environment is further improved, dust emission reaches emission requirements of new standards, the emission amount is smaller than or equal to 8mg/Nm<3>, and emission is stable.

The invention discloses a neutron material level meter and a delayed coking liquid level analysis system. The neutron material level meter comprises a shell body, wherein an opening is formed in the front side of the shell body; a baffle with an air vent is formed in the rear side of the shell body; a supporting frame is arranged on the inner side of the shell body; a transmitter explosion-proof shell is arranged at the top of the supporting frame; a transmitter connected with a neutron material level meter main engine is arranged in the transmitter explosion-proof shell; two neutron detector explosion-proof shells are arranged below the transmitter explosion-proof shell, wherein at least one neutron detector explosion-proof shell is internally provided with a helium-3 pipe connected with the transmitter; a neutron radioactive source mounting shell is arranged between the two neutron detector explosion-proof shells; a neutron radioactive source mounting hole is formed in the top of the shell body; a hole cover capable of being opened and closed is arranged on the neutron radioactive source mounting hole. According to the neutron material level meter disclosed by the invention, a scattering and moderation principle of neutrons in a hydrogen-containing medium is used for distinguishing a dynamic distribution rule of states of all materials in a tower; an upper-layer real-time height indication value of a coke layer is given under the matching of a tower-bottom oil injection starting signal.

The invention relates to a determining method for the positions of reinforcing of gob-side entry roofs through cable-stayed anchor cables. As for traditional reinforcing of the gob-side entry roofs, anchor cables inclining towards entity coal sides are driven nearby roadway filled bodies to protect the stability of retained roadways, but the actual effect is very poor. The method is particularly suitable for determining of arrangement of the cable-stayed anchor cables of the gob-side entry roofs. According to the method, the poor effect of reinforcing of the roofs through the roof cable-stayedanchor cables is mainly caused by the unreasonable designed and arranged positions of the retained roadway roof cable-stayed anchor cables, thus in the method, the retained roadway roofs are regardedas thin plates each with one pair of opposite edges being fixedly and simply supported and the other pair of opposite edges being free, maximum and minimum main stress expressions of the thin platesare obtained through calculation, the maximum main stress of the thin plates is compared with the rock tensile strength, thus the stress ratio coefficient of the thin plates is obtained, when the stress ratio coefficient is larger than 1, rock plates are damaged, and the position needs to be reinforced by driving the cable-stayed anchor cables. According to the method, calculation is easy, achievement is easy, and safety and reliability are achieved.

The invention discloses a roof brushed frame moving valve of a hydraulic support for a coal mine. The roof brushed frame moving valve comprises a valve body, a high-pressure liquid inlet, a liquid returning opening and a control liquid opening, wherein the high-pressure liquid inlet, the liquid returning opening and the control liquid opening are formed in the valve body; the valve body is internally provided with a hydraulic control one-way valve and a one-way valve; a working cavity of the hydraulic control one-way valve is communicated with the high-pressure liquid inlet; an unloading cavity of the hydraulic control one-way valve is communicated with a liquid inlet of the one-way valve; a liquid outlet of the one-way valve is communicated with the liquid returning opening; the control liquid opening is communicated with the lower end face of an ejection rod of the hydraulic control one-way valve. The roof brushed frame moving valve disclosed by the invention has the advantages that a frame can be moved under pressure when the hydraulic support works under a well, that is, a roof beam and a roof plate can contact mutually all the time when the hydraulic support is moved and the hydraulic support also has certain supporting force on the roof plate when the hydraulic support is removed, so as to prevent an unstable direct roof, a false roof or a crushed roof from caving and puking. Meanwhile, when the hydraulic support is moved, a column does not need to be descended and only pressure in a stand column of the hydraulic bracket needs to be reduced to a pre-set value to carry out frame moving operation.