Automatic grouting device for repairing hole wall of drill hole and construction method

Abstract

The invention discloses an automatic grouting device for repairing the hole wall of a drill hole and a construction method, and the automatic grouting device comprises a slurry box used for loading slurry; the grouting anchor rod is connected with the slurry box; the grouting pump comprises a liquid nitrogen tank for loading liquid nitrogen; the cold water tank is loaded with first cooling liquid, and the temperature of the first cooling liquid is lower than the boiling point of the liquid nitrogen; the hot water tank is loaded with second cooling liquid, and the temperature of the second cooling liquid is higher than the boiling point of the liquid nitrogen; the heat conduction pipe is coiled on the liquid nitrogen tank, and the heat conduction pipe is selectively communicated with the cold water tank or the hot water tank so as to liquefy or gasify the liquid nitrogen; and the movable push rod is movably arranged between the liquid nitrogen box and the slurry box, and when the liquid nitrogen is gasified, the movable push rod is pushed to pressurize the slurry box, so that the slurry is injected into the grouting anchor rod. The pneumatic driving effect is achieved through temperature control, the drilling repair cost is reduced, and safety is improved.

Description

Technical Field

[0001] The invention belongs to the field of borehole repair in coal mines, and in particular relates to an automatic grouting device and a construction method for repairing a borehole wall. Background Art

[0002] As mining gradually shifts to deeper areas, the surrounding rock stress environment becomes more complex, and the deep drilling control problem becomes increasingly prominent, which brings many difficulties to deep well high-stress soft rock drilling. On the other hand, under the complex surrounding rock stress environment, cracks in the coal (rock) body are very easy to develop, and the conduction of cracks will produce the phenomenon of non-directional flow of gas, which will accelerate the reduction of gas extraction concentration. The problem of repairing boreholes after deformation has seriously restricted the development of the gas extraction field. Through the gas concentration test in the borehole, the boreholes with repair value are selected, and then the boreholes are reinforced by grouting to improve the overall extraction life of the borehole. Therefore, there is an urgent need for an automatic grouting device and construction method for repairing the borehole wall.

[0003] At present, the driving form of shotcrete pumps used in tunnel engineering is mostly electric drive. 4 , CO, H 2 According to statistics, more than 70% of coal mine gas and coal dust explosion accidents and underground external fire accidents are caused by sparks from electrical equipment, mechanical equipment or non-metallic materials. Summary of the invention

[0004] The purpose of the present invention is to provide an automatic grouting device and construction method for repairing borehole walls, which utilizes thermal energy to convert liquid nitrogen into nitrogen gas, and then injects the slurry into the injection area through gas work, thereby changing the traditional use of electric drive equipment, which brings about underground explosion-proof requirements and makes the process complicated. More importantly, no electricity is used, and the explosion problem of underground explosive gas environment caused by electrical explosion is completely eliminated.

[0005] To achieve the above-mentioned purpose, the present invention adopts an automatic grouting device for repairing a borehole wall, comprising: A slurry tank, used for loading slurry; A grouting anchor rod connected to the slurry box; Grouting pump, including: Liquid nitrogen tank, loaded with liquid nitrogen; A cold water tank loaded with a first coolant, wherein the temperature of the first coolant is lower than the boiling point of liquid nitrogen; a hot water tank loaded with a second coolant having a temperature higher than a boiling point of liquid nitrogen; A heat conducting pipe, coiled around the liquid nitrogen tank, the heat conducting pipe being selectively connected to the cold water tank or the hot water tank to liquefy or gasify the liquid nitrogen; A movable push rod is movably arranged between the liquid nitrogen box and the slurry box. When the liquid nitrogen is gasified, the movable push rod is pushed to pressurize the slurry box so that the slurry is injected into the grouting anchor.

[0006] Furthermore, the grouting anchor comprises: The anchor body is provided with a grouting channel, and the grouting channel is communicated with the slurry tank; A linkage grouting port, connected to the grouting channel; Bag A and bag B are respectively located at both sides of the linkage grouting port and are respectively connected to the grouting channel.

[0007] Furthermore, the anchor rod body is provided with an air hole and a gas extraction pipeline connected to the air hole, and the grouting anchor rod further comprises: A first push rod is slidably disposed on the linkage grouting port and is capable of closing or opening the air hole; An elastic member, whose two ends are respectively connected to the anchor rod body and the first push rod, so as to push the first push rod to open the air hole, and when the slurry passes through the linkage grouting port, the first push rod is pushed to move to compress the elastic member and close the air hole; The automatic grouting device for repairing the borehole wall also includes: A gas detection device is connected to the gas production pipeline, and the gas detection device includes: The gas sensor is connected to the gas production pipeline through a pipeline; The second push rod is connected to the driving member to open or close the pipeline between the gas sensor and the gas production pipeline under the driving of the driving member.

[0008] Furthermore, the automatic grouting device also includes: A pressure regulator is provided between the slurry box and the grouting anchor rod, and is used to adjust the slurry pressure entering the grouting anchor rod; A first bursting valve is provided between the bladder bag A and the grouting channel. When the slurry pressure exceeds the first pressure, the slurry enters the bladder bag A through the first bursting valve; A second bursting valve is provided between the linkage grouting port and the grouting channel. When the slurry pressure exceeds the second pressure, the slurry enters the linkage grouting port through the second bursting valve; The bladder A is closer to the slurry box than the bladder B, and the first pressure is less than the second pressure.

[0009] Furthermore, the gas detection device also includes: The waste gas collection bag is connected to the gas sensor through a pipeline; a first one-way valve is provided between the gas sensor and the gas collection pipeline, and a second one-way valve is provided between the gas sensor and the waste gas collection bag; when the second push rod opens the pipeline between the gas sensor and the gas collection pipeline, the first one-way valve opens and the second one-way valve closes, allowing the gas to enter the gas sensor; when the second push rod closes the pipeline between the gas sensor and the gas collection pipeline, the first one-way valve closes and the second one-way valve opens, allowing the gas to enter the waste gas collection bag.

[0010] Furthermore, the first coolant and the second coolant are both liquid oxygen, the temperature of the first coolant is -200°C, and the temperature of the second coolant is -180°C.

[0011] Furthermore, a buffer belt is provided in the slurry box, and the buffer belt is used to increase the friction between the buffer belt and the movable push rod to slow down the moving speed of the movable push rod.

[0012] Furthermore, the automatic grouting device comprises a plurality of grouting anchor rods, and the plurality of grouting anchor rods are respectively connected to the slurry box through pipelines.

[0013] The present invention also provides a construction method for repairing a borehole wall, using an automatic grouting device for repairing a borehole wall, comprising the steps of: S1: Place the grouting anchor rod into the borehole to be repaired and connect it to the slurry box; S2: The heat conducting pipe is connected to the hot water tank to introduce the second coolant, which heats the liquid nitrogen to gasify it and pushes the movable push rod to pressurize the slurry tank so that the slurry is injected into the grouting anchor.

[0014] Furthermore, step S2 specifically includes: S21: injecting slurry into bag B to make bag B expand and combine with coal and rock mass; S22: The driving member drives the second push rod to open the connection with the gas production pipeline to detect the gas concentration. If the gas concentration is less than the set value, S23 is executed; otherwise, S24 is executed; S23: draining the serous fluid from the pouch B; S24: increasing the pressure on the slurry box to make it break through the first blasting valve and enter the bag A, so that the bag A expands and combines with the coal and rock mass; S25: further increase the pressure on the slurry box to break through the second bursting valve and enter the linkage grouting port, push the first push rod in the linkage grouting port to move, close the gas production pipeline, and allow the slurry to enter the area to be grouted.

[0015] The present invention has the combined functions of automatic gas concentration monitoring and grouting drilling repair, and cooperates with cold and hot high-pressure gas grouting to achieve high quality of drilling repair. The automatic switching technology reduces the manual error rate and the cost of drilling repair. The movable integrated design facilitates the installation and operation of the equipment during the construction process.

[0016] Advantages: The present invention integrates gas concentration detection, high-pressure drilling repair and hot and cold pneumatic conversion technology, and integrates several major technologies to improve the effect of drilling repair. At the same time, the device is reusable and portable, with strong innovation and practical applicability, and can effectively promote the development of the drilling repair industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a main diagram of the automatic temperature control grouting equipment according to an embodiment of the present invention; Figure 2 This is an initial display diagram of a gas concentration detection channel according to an embodiment of the present invention; Figure 3 This is a closed display diagram of a gas concentration detection channel according to an embodiment of the present invention; Figure 4 This is a startup display diagram of the bag B according to the embodiment of the present invention; Figure 5 This is a startup display diagram of the bag A according to an embodiment of the present invention; Figure 6 This is a diagram showing the drilling repair process according to an embodiment of the present invention; Figure 7 This is a diagram showing the multi-drilling linkage process of an embodiment of the present invention; Figure 8 for Figure 1 An enlarged view of the first part of the main body diagram of the automatic temperature control grouting equipment; Fig. 9 for Figure 1 An enlarged view of the second part of the main body diagram of the automatic temperature control grouting equipment.

[0018] In the figure: 1- switch 1; 2- cold water inlet; 3- switch 2; 4- hot water inlet; 5- switch 3; 6- liquid nitrogen inlet; 7- switch 4; 8- slurry inlet; 9- buffer belt; 10- reset spring 1; 11- power supply; 12- main switch; 13- central controller; 14- holder; 15- bus; 16- cold water outlet; 17- water inlet; 18- moving wheel; 19- switch 5; 20- controller 1; 21- switch 6; 22- switch 7; 2 3-hot water inlet; 24-controller 2; 25-hot water outlet; 26-switch 8; 27-heat pipe; 28-pressure sensor; 29-movable push rod; 30-pressure regulator; 31-switch 9; 32-coal rock mass; 33-grouting area; 34-extraction drilling hole; 35-insulation board; 36-heater; 37-temperature sensor; 38-screen display; 39-refrigerator; 40-water level sensor 1; 42-water level sensor 2; 43-water level Sensor 3; 44- alarm; 45- cold water tank; 46- hot water tank; 47- liquid nitrogen tank; 48- slurry tank; 49- grouting pump body; 50- limiter; 51- gas pressure pump; 52- first one-way valve; 53- automatic gas detection device; 54- screw rod; 55- synchronous motor; 56- joint 1; 57- anchor rod body; 58- bag A; 59- gas production pipeline; 60- air inlet 2; 61- first bursting valve; 62- second bursting valve; 63- First push rod; 64-reset spring 2; 65-air hole; 66-second push rod; 67-second one-way valve; 68-gas sensor; 69-connector 2; 70-linked grouting port; 71-bag B; 72-waste gas collecting bag; 2-1-switch A; 2-2-switch B; 2-3-switch C; 2-4-switch D; 2-5-switch E; 2-6-switch AA; 2-7 switch BB; 2-8 switch CC; 2-9 switch DD; 2-10-switch EE. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings. Example 1

[0020] See also Figure 1 , Figure 8 and Fig. 9 Embodiment 1 of the present invention provides an automatic grouting device for repairing a borehole wall, comprising a grouting pump, a grouting anchor rod and a gas detection device. The grouting pump is used to grout the grouting anchor rod. The gas detection device is connected to the grouting anchor rod and is used to detect the gas content.

[0021] The grouting pump includes a cold water tank, a hot water tank, a liquid nitrogen tank, a slurry tank, a control end and a mobile end which can be assembled in sequence. The cold water tank, the hot water tank, the liquid nitrogen tank and the slurry tank are arranged in sequence at the mobile end. The mobile end can drive the grouting pump to move. The control end is used to control the operation of the grouting pump.

[0022] A cold water inlet 2 is provided at the top of the cold water tank. A switch 1 is provided at the cold water inlet 2. A refrigerator and a water level sensor are provided in the cold water tank. The refrigerator and the water level sensor are installed at the lower end of the cold water tank and are connected to the central controller through a bus.

[0023] Furthermore, the refrigerator constantly controls the water temperature of the cold water tank at -200 degrees Celsius. The water level monitoring value of the water level sensor is preset by the central controller. If the value is lower than the preset value, the central controller will activate the alarm.

[0024] The top of the hot water tank is provided with a hot water inlet. A switch 2 is provided at the hot water inlet. A heater, a temperature sensor, a water level sensor and a heat preservation board are provided in the hot water tank.

[0025] The heater, temperature sensor and water level sensor are installed at the lower end of the hot water tank and connected to the central controller through a bus.

[0026] Furthermore, the heating is linked to the temperature sensor to constantly control the water temperature of the hot water tank at -180°C. The water level monitoring value of the water level sensor is preset by the central controller. If the value is lower than the preset value, the central controller will activate the alarm.

[0027] The cold water tank is loaded with liquid oxygen at -200°C, and the hot water tank is loaded with liquid oxygen at -180°C.

[0028] The top of the liquid nitrogen box is provided with a liquid nitrogen adding port. A switch 3 is provided at the liquid nitrogen adding port. The liquid nitrogen box is provided with a heat conducting pipe, a water level sensor, a pressure sensor, a stopper and a movable push rod.

[0029] The water level sensor is installed at the lower end of the liquid nitrogen box, and the pressure sensor is installed on the movable push rod, which are connected to the central controller through a bus.

[0030] The heat pipe is wound around the liquid nitrogen box, and efficient heat exchange can be carried out between the heat pipe and the liquid nitrogen box. The heat pipe can be selectively connected to a cold water tank or a hot water tank. The heat pipe is used to exchange heat with the liquid nitrogen in the liquid nitrogen box to cool or heat the liquid nitrogen to liquefy or gasify it.

[0031] Specifically, the water inlet end of the heat pipe is connected to the tee, one end of the tee is connected to the switch 8 and the water outlet end of the hot water pump in sequence, and the other end of the tee is connected to the switch 6 and the water outlet end of the cold water pump in sequence. The water outlet end of the heat pipe is connected to the tee, one end of the tee is connected to the switch 5 and the water inlet end of the cold water pump in sequence, and the other end of the tee is connected to the switch 7 and the water inlet end of the hot water pump in sequence.

[0032] The movable push rod is movably arranged between the liquid nitrogen box and the slurry box. The movable push rod separates the liquid nitrogen box and the slurry box. When the liquid nitrogen is gasified, the volume expands and pushes the movable push rod to move and pressurize the slurry box.

[0033] The stopper is used to limit the axial movement range of the movable push rod.

[0034] A slurry adding port is provided on the top of the slurry box. A switch 4 is provided at the slurry adding port. A return spring 1 and a buffer belt are provided in the slurry box.

[0035] One end of the reset spring 1 is fixed to the grouting pump body and the other end is fixed to the movable push rod, which is used to push the movable push rod to reset. When the reset spring 1 is subjected to the force from the movable push rod, the reset spring is contracted. The contraction of the reset spring requires the pressure in the liquid nitrogen box to reach at least 2MPa.

[0036] Furthermore, the slurry adding port is connected to a slurry concentration box in the tunnel.

[0037] Furthermore, there is sliding friction between the buffer belt and the movable push rod, which can slow down the kinetic energy of the movable push rod.

[0038] The control end includes a low-voltage power supply, a main switch, a central controller, an alarm, a screen display and a bus. The low-voltage power supply provides power to all electrical devices, and the main switch can be used to cut off the power supply of all devices. The central controller is mainly used for processing device data and issuing instructions. The alarm prompts the working status of the device through sound. The screen display can display the operating status of the device and the data measured by various sensors in real time.

[0039] Furthermore, the power supply is an intrinsically safe device, a low voltage power supply, and not a strong power supply. Since there is no need to drive the slurry injection, the power supply can be a low voltage power supply below 36V.

[0040] The mobile end includes a fixture and a mobile wheel. The main body of the grouting pump is located above the mobile end, the fixture is mainly used to fix the grouting equipment, and the mobile wheel is used to transfer the working location of the grouting equipment.

[0041] The grouting anchor includes an anchor body and is provided with a linkage grouting port and an air hole. The linkage grouting port is connected to the grouting channel, and the slurry is injected into the target grouting area through the linkage grouting port. The air hole is connected to the gas production pipeline to introduce the gas into the gas detection device.

[0042] The grouting anchor also includes a bag A, a bag B and a first burst valve. Bag A and bag B are respectively located on both sides of the linkage grouting port and are respectively connected to the grouting channel. Bag A is located at the proximal end of the anchor body, and bag B is located at the distal end of the anchor body.

[0043] The first bursting valve is arranged at the bag A. When the slurry pressure exceeds the first pressure, the slurry enters the linkage grouting port through the first bursting valve. The bag B is directly connected to the anchor rod body.

[0044] After being filled with slurry, bags A and B will expand and swell, and will be tightly bonded with the coal rock mass.

[0045] like Figure 4 , 5 As shown in Figure 6, after being filled with slurry, the bag will expand and expand, and the bag and the coal rock mass are tightly combined. Bag A is connected to the grouting anchor through a bursting valve; bag B is directly connected to the grouting anchor.

[0046] like Figure 4 , bag B expands, and bag B and the borehole form a closed space in the direction of the borehole. At this time, the synchronous motor and spiral tube of the automatic gas detection device move forward, which can be used to extract the gas containing gas in the borehole. The gas concentration sensor uploads the detection data to the central processor in real time.

[0047] like Figure 5 , both bags A and B expand, and a closed space is formed between the two bags. Figure 3 , the slurry breaks through the bursting valve, causing the push rod to move forward and the air hole to close. Figure 6 , the slurry begins to enter the area to be grouting.

[0048] The grouting anchor also includes a first push rod and an elastic member. The first push rod is slidably disposed on the anchor body. The elastic member connects the anchor body and the first push rod to pull the first push rod to the linkage grouting port. At this time, the air hole is in an open state, and the gas in the borehole can enter the gas production pipeline through the air hole. When the slurry passes through the linkage grouting port, the first push rod is pushed to move to compress the elastic member and close the air hole. At this time, the gas in the borehole cannot enter the gas production pipeline through the air hole.

[0049] like Figure 2 The linkage grouting port includes a bursting valve, a push rod, a reset spring 2, and an air hole. One end of the reset spring 2 is connected to the push rod, and the other end is connected to the anchor rod body. The spring is in the original state, the air hole is in the open state, and the gas in the borehole can be extracted through the air hole.

[0050] like Figure 3 Under the pressure of the slurry, the push rod moves forward, the return spring is in a compressed state, the air hole is in a closed state, and the gas in the borehole cannot enter the gas production pipeline through the air hole.

[0051] A second bursting valve is also provided at the linkage grouting port. When the slurry pressure exceeds the second pressure, the slurry enters the linkage grouting port through the second bursting valve.

[0052] The grouting anchor rod is detachably connected to the slurry tank via a joint 1. A switch 9 is also provided between the grouting anchor rod and the slurry tank to control the on-off; and a pressure regulator is provided to control the pressure of the slurry passing through.

[0053] By limiting the slurry pressure through the pressure regulator, it is possible to control whether the slurry breaks through the first bursting valve / the second bursting valve.

[0054] The gas detection device is located on the mobile end of the grouting pump. The gas detection device is connected to the gas production pipeline. The gas production pipeline includes a pipe, a joint 2 and an air inlet, etc., which are used to transmit gas. The gas production pipeline can also be provided in the form of a channel in the anchor body.

[0055] The gas detection device includes a gas sensor, a synchronous motor, a screw rod, a second push rod, a first one-way valve and a second one-way valve. The gas sensor is connected to the central sensor through a bus, and the central sensor displays the data visually through a screen display and an alarm sound reminder.

[0056] The second push rod can move to open or close the pipeline between the gas sensor and the gas production pipeline. In this embodiment, the synchronous motor drives the spiral rod to rotate forward, the push rod moves upward, and the pipeline is opened; the synchronous motor drives the spiral rod to rotate reversely, and the push rod moves downward to close the pipeline.

[0057] The gas sensor is also connected to the exhaust gas collection bag via a pipe.

[0058] The first one-way valve is arranged between the second push rod and the gas sensor. The second one-way valve is arranged between the gas sensor and the exhaust gas collecting bag.

[0059] When the pipeline is opened, the first one-way valve opens, the second one-way valve closes, the gas is collected through the gas production pipeline, and the gas sensor detects the gas concentration in real time.

[0060] When the pipeline is closed, the first one-way valve opens and the second one-way valve closes, and the exhaust gas is discharged into the exhaust gas collection bag.

[0061] like Figure 7 As shown, the automatic grouting device can be provided with multiple grouting anchors to perform grouting work in multiple holes. Multiple switches are provided on the grouting anchors and gas production pipelines in multiple holes, and by closing the switches, one grouting pump drives the repair work of multiple boreholes.

[0062] Specific settings such as Figure 7 As shown, the on and off of slurry and gas are respectively limited by switch A, switch B, switch C, switch D, switch E, switch AA, switch BB, switch CC, switch DD, and switch EE.

[0063] The present invention also provides a construction method for repairing a borehole wall, comprising the steps of: S1: Place the grouting anchor rod into the borehole to be repaired and connect it to the slurry box; S2: The heat conducting pipe is connected to the hot water tank to introduce the second coolant, which heats the liquid nitrogen to gasify it and pushes the movable push rod to pressurize the slurry tank so that the slurry is injected into the grouting anchor.

[0064] Step S2 specifically includes: S21: injecting slurry into bag B to make bag B expand and combine with coal and rock mass; S22: The driving member drives the second push rod to open the connection with the gas production pipeline to detect the gas concentration. If the gas concentration is less than the set value, S23 is executed; otherwise, S24 is executed; S23: draining the serous fluid from the pouch B; S24: increasing the pressure on the slurry box to make it break through the first blasting valve and enter the bag A, so that the bag A expands and combines with the coal and rock mass; S25: further increase the pressure on the slurry box to break through the second bursting valve and enter the linkage grouting port, push the first push rod in the linkage grouting port to move, close the gas production pipeline, and allow the slurry to enter the area to be grouted.

[0065] The following is a specific description through Examples 2 and 3. Example 2

[0066] The specific use of the automatic grouting device for single-hole construction includes: S1: Assembly of automatic grouting device Install wires, heat transfer pipes, liquid nitrogen containers, slurry containers, return springs, pressure sensors, switches, water level sensors, and shotcrete pipes, etc.

[0067] Connect switches 1, 2, 3, 4, 5, 6, 7, 8, pressure module, controller 1 and controller 2 to the central controller in sequence through wires; connect switch 5 and switch 6 to controller 1 through wires; and connect switch 7 and switch 8 to controller 2 through wires.

[0068] Connect the water inlet end of the heat pipe to the tee, one end of the tee is connected to the switch 8 and the water outlet end of the hot water pump in sequence, and the other end of the tee is connected to the switch 6 and the water outlet end of the cold water pump in sequence; connect the water outlet end of the heat pipe to the tee, one end of the tee is connected to the switch 5 and the water inlet end of the cold water pump in sequence, and the other end of the tee is connected to the switch 7 and the water inlet end of the hot water pump in sequence.

[0069] Connect the cold water inlet and the hot water inlet to the liquid oxygen tank respectively, connect the liquid nitrogen addition port to the external liquid nitrogen bottle, and connect the slurry addition port to the external slurry tank.

[0070] S2: Automatic liquid nitrogen replenishment process.

[0071] Turn on the power supply and switch 3 of the central controller, switch 3 uploads the signal to the central controller, and the central controller transmits the signal to switch 2, switch 3, controller 1 and controller 2, and switches 2, 3, 4, 5, 6, 7 and 8 are closed; if the liquid circulation volume is 200L, switch 3 uploads the signal to the central controller, and the central controller controls switch 3 to close and switch 4 to open.

[0072] S3: Automatic slurry replenishment process.

[0073] Switch 4 uploads the signal to the central controller, and the central controller transmits the signal to controller 1. Switches 5 and 6 are turned on, and cold water circulates through the cold water pump and the heat transfer pipe. The heat transfer pipe transfers the heat of the gaseous nitrogen in the spraying pump to the cold water in the water pipe.

[0074] S4: Slurry pressurization process.

[0075] If the liquid flow rate is 500L, switch 4 will upload the signal to the central controller, and the central controller will transmit the signal to switches 4, 9 and controllers 1 and 2. Switches 2, 5 and 6 will be closed, and switches 7 and 8 will be opened. The hot water will circulate through the hot water pump and the heat transfer pipe, and the heat transfer pipe will transfer the heat to the liquid nitrogen in the spray pump. After 5 minutes, the central controller will control switch 9 to open, and the slurry will be sprayed out through the spray port. After waiting for 2 minutes, the central controller will control switches 9, 7 and 8 to close, and switch 4 will be opened to enter S2.

[0076] S5: Anchor bolt installation and borehole gas concentration detection.

[0077] Put the anchor rod into the borehole to be repaired, connect the switch 9 and the grouting pipe through the joint 1, and the grouting pipe is sequentially connected to the bag A, the linkage grouting port and the bag B. Connect the automatic gas detection device and the gas production pipe through the joint 2, and the gas production pipe is sequentially connected to the linkage grouting port and the air inlet 2.

[0078] Switch 9 is turned on, the pressure regulator starts working, the slurry is injected into the anchor rod at a pressure of 1Mpa, and the bag B expands and expands to tightly combine with the coal rock. After 2 minutes, the gas detection device starts working, the synchronous motor drives the screw rod to rotate forward, the second push rod moves upward and the first one-way valve opens, and the gas in the borehole is sucked into the automatic gas detection device. The gas sensor uploads the gas data to the central sensor in real time, and the central sensor controls the screen display and the alarm. If the gas concentration is less than 15%, the alarm starts to sound a reminder "not in compliance with the specified requirements", open the joint 1, and discharge the slurry in the bag B; if the gas concentration is greater than or equal to 15%, the alarm starts to sound a reminder "in compliance with the specified requirements", and the drilling repair process is started.

[0079] S6: Drilling repair process.

[0080] The pressure regulator controls the slurry to start entering the anchor bolt at a pressure of 1.5Mpa, the slurry breaks through the first bursting valve, and the bag A begins to expand. When the slurry pressure is greater than 1.5Mpa, the slurry breaks through the second bursting valve and enters the linkage grouting port, pushing the first push rod in the linkage grouting port forward, the gas production pipeline is closed, and the slurry begins to enter the area to be grouted at a rate of 0.1Mpa / min until the grouting pressure reaches 2Mpa.

[0081] S7: Device removal process.

[0082] After the drilling repair work of the device is completed and the construction task is completed, the power supply of the central controller is cut off, and switches 1, 2, 3, 4, 5, 6 and 7 automatically enter the closed state; remove joints 1 and 2, and discharge the excess slurry in bags A and B through joint 1. Example 3

[0083] Specific use methods for porous construction: S1-S4 are the same as single hole construction.

[0084] S5 multi-porous anchor installation and drilling gas concentration detection.

[0085] Put the anchor rods into the boreholes to be repaired, respectively, connect the switch 9 and the grouting pipeline through joints 2-6, 2-7, 2-8, 2-9 and 2-10, respectively, and the grouting pipeline is connected to the bag A, the linkage grouting port and the bag B in sequence. Connect the automatic gas detection device and the gas production pipeline through switch 9. Connect the gas production pipeline through joints 2-1, 2-2, 2-3, 2-4 and 2-5.

[0086] Switch 9 and switch 2-6 are turned on, 2-7, 2-8, 2-9 and 2-10 are turned off, the pressure regulator is turned on, the slurry is injected into the anchor at a pressure of 1Mpa, and the bag B expands and expands to tightly combine with the coal rock mass. After 2 minutes, the gas detection device starts to work, the synchronous motor drives the screw rod to rotate forward, the push rod moves upward and the first one-way valve opens, and the gas in the borehole is sucked into the automatic gas detection device. The gas sensor uploads the gas data to the central sensor in real time, and the central sensor controls the screen display and the alarm. If the gas concentration is less than 15%, the alarm starts to sound a reminder "not in compliance with the specified requirements", open joint 1, and discharge the slurry in bag B; if the gas concentration is greater than or equal to 15%, the alarm starts to sound a reminder "in compliance with the specified requirements", and the drilling repair process is started.

[0087] Switch 2-7 is turned on, and switches 2-5, 2-8, 2-9 and 2-10 are turned off, and the above process is repeated in sequence to find a drill hole that meets the repair conditions.

[0088] S6: Porous repair process.

[0089] The pressure regulator controls the slurry to start entering the anchor rods of multiple boreholes at a pressure of 1.5Mpa. The slurry breaks through the first bursting valve, and the bag A begins to expand. When the slurry pressure is greater than 1.5Mpa, the slurry breaks through the second bursting valve and enters the linkage grouting port, pushing the push rod in the linkage grouting port forward, the gas production pipeline is closed, and the slurry begins to enter the area to be grouted at a rate of 0.1Mpa / min until the grouting pressure reaches 2Mpa.

[0090] S7: The process of taking out the porous device.

[0091] After the drilling and repair work of the device is completed and the construction task is completed, the power supply of the central controller is cut off, and switches 1, 2, 3, 4, 5, 6 and 7 automatically enter the closed state; remove joints 2-6, 2-7, 2-8, 2-9 and 2-10, and drain the excess slurry in bags A and B through joint 1. Remove joints 2-1, 2-2, 2-3, 2-4 and 2-5 of the gas production pipeline.

[0092] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. However, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An automatic grouting device for repairing a borehole wall, comprising: A slurry tank, used for loading slurry; A grouting anchor rod connected to the slurry box; It is characterized by further comprising: Grouting pump, including: Liquid nitrogen tank, loaded with liquid nitrogen; A cold water tank loaded with a first coolant, wherein the temperature of the first coolant is lower than the boiling point of liquid nitrogen; a hot water tank loaded with a second coolant having a temperature higher than a boiling point of liquid nitrogen; A heat conducting pipe, coiled around the liquid nitrogen tank, the heat conducting pipe being selectively connected to the cold water tank or the hot water tank to liquefy or gasify the liquid nitrogen; A movable push rod is movably arranged between the liquid nitrogen box and the slurry box. When the liquid nitrogen is gasified, the movable push rod is pushed to pressurize the slurry box so that the slurry is injected into the grouting anchor.

2. The automatic grouting device for repairing a borehole wall according to claim 1, characterized in that: The grouting anchor comprises: The anchor body is provided with a grouting channel, and the grouting channel is communicated with the slurry tank; A linkage grouting port, connected to the grouting channel; Bag A and bag B are respectively located at both sides of the linkage grouting port and are respectively connected to the grouting channel.

3. The automatic grouting device for repairing a borehole wall according to claim 2 is characterized in that: The anchor rod body is provided with an air hole and a gas extraction pipeline connected to the air hole, and the grouting anchor rod further comprises: A first push rod is slidably disposed on the linkage grouting port and is capable of closing or opening the air hole; An elastic member, whose two ends are respectively connected to the anchor rod body and the first push rod, so as to push the first push rod to open the air hole, and when the slurry passes through the linkage grouting port, the first push rod is pushed to move to compress the elastic member and close the air hole; The automatic grouting device for repairing the borehole wall also includes: A gas detection device is connected to the gas production pipeline, and the gas detection device includes: The gas sensor is connected to the gas production pipeline through a pipeline; The second push rod is connected to the driving member to open or close the pipeline between the gas sensor and the gas production pipeline under the driving of the driving member.

4. The automatic grouting device for repairing a borehole wall according to claim 3 is characterized in that: The automatic grouting device also includes: A pressure regulator is provided between the slurry box and the grouting anchor rod, and is used to adjust the slurry pressure entering the grouting anchor rod; A first bursting valve is provided between the bladder bag A and the grouting channel. When the slurry pressure exceeds the first pressure, the slurry enters the bladder bag A through the first bursting valve; A second bursting valve is provided between the linkage grouting port and the grouting channel. When the slurry pressure exceeds the second pressure, the slurry enters the linkage grouting port through the second bursting valve; The bladder A is closer to the slurry box than the bladder B, and the first pressure is less than the second pressure.

5. The automatic grouting device for repairing a borehole wall according to claim 3 is characterized in that: The gas detection device also includes: The waste gas collection bag is connected to the gas sensor through a pipeline; a first one-way valve is provided between the gas sensor and the gas collection pipeline, and a second one-way valve is provided between the gas sensor and the waste gas collection bag; when the second push rod opens the pipeline between the gas sensor and the gas collection pipeline, the first one-way valve opens and the second one-way valve closes, allowing the gas to enter the gas sensor; when the second push rod closes the pipeline between the gas sensor and the gas collection pipeline, the first one-way valve closes and the second one-way valve opens, allowing the gas to enter the waste gas collection bag.

6. The automatic grouting device for repairing a borehole wall according to claim 1, characterized in that: The first coolant and the second coolant are both liquid oxygen, the temperature of the first coolant is -200°C, and the temperature of the second coolant is -180°C.

7. The automatic grouting device for repairing a borehole wall according to claim 1, characterized in that: A buffer belt is arranged in the slurry box, and the buffer belt is used to increase the friction force between the buffer belt and the movable push rod to slow down the moving speed of the movable push rod.

8. The automatic grouting device for repairing a borehole wall according to claim 1, characterized in that: The automatic grouting device comprises a plurality of grouting anchor rods, and the plurality of grouting anchor rods are respectively connected to the slurry box through pipelines.

9. A construction method for repairing a borehole wall, using the automatic grouting device for repairing a borehole wall as claimed in claim 4, characterized in that: Includes steps: S1: Place the grouting anchor rod into the borehole to be repaired and connect it to the slurry box; S2: The heat conducting pipe is connected to the hot water tank to introduce the second coolant, which heats the liquid nitrogen to gasify it and pushes the movable push rod to pressurize the slurry tank so that the slurry is injected into the grouting anchor.

10. The construction method for repairing a borehole wall according to claim 9, characterized in that: Step S2 specifically includes: S21: injecting slurry into bag B to make bag B expand and combine with coal and rock mass; S22: The driving member drives the second push rod to open the connection with the gas production pipeline to detect the gas concentration. If the gas concentration is less than the set value, S23 is executed; otherwise, S24 is executed; S23: draining the serous fluid from the pouch B; S24: increasing the pressure on the slurry box to make it break through the first blasting valve and enter the bag A, so that the bag A expands and combines with the coal and rock mass; S25: further increase the pressure on the slurry box to break through the second bursting valve and enter the linkage grouting port, push the first push rod in the linkage grouting port to move, close the gas production pipeline, and allow the slurry to enter the area to be grouted.

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