A high pressure foam swelling and fracturing rock system and method of use thereof

Abstract

The application relates to the technical field of rock breaking equipment, and particularly relates to a high-pressure foam swelling and cracking rock breaking system and a use method thereof. The application realizes effective storage and release of high-pressure foam through a precisely designed structure. The unique conical foam outlet and piston rod design can keep the foam storage cavity in a sealed state under the action of the pressure regulating spring until the foam storage cavity is opened after the pressure in the foam storage cavity reaches a preset value. Once the pressure is sufficient, the piston will move to the left under the action of the foam pressure and collide with the limiting block, instantaneously opening the foam outlet and releasing the high-pressure foam. The foam release mode effectively increases stress waves and quasi-static forces generated when the foam impacts a rock hole, so that the foam swelling and cracking force can act on the rock hole instantaneously, realizing efficient rock breaking. Meanwhile, the separated cavity design in the device enables the pressure relief cavity to form a negative pressure state when the foam is instantaneously released, further enhancing the suction force on the left side of the piston rod and ensuring rapid release of the foam.

Description

Technical Field

[0001] This application relates to the field of rock-breaking equipment technology, specifically a high-pressure foam expansion rock-breaking system and its usage method. Background Technology

[0002] Currently, blasting is the most common method for breaking rocks in mine roadway and traffic tunnel excavation projects. The blasting process involves drilling holes in the rock surface, placing high-energy chemical explosives at appropriate locations within the holes and sealing them, and finally detonating the explosives, breaking the rock. Relevant theoretical and experimental studies show that the rock breaks under the combined effect of the impact stress wave generated by the explosive detonation and the quasi-static force generated by the high-temperature, high-pressure gas. However, conventional blasting methods generate sparks, toxic and harmful fumes, and dust during rock breaking, threatening the normal operation of equipment and the health and safety of personnel at the rock-breaking face. Chemical explosives are strictly controlled substances, with stringent requirements for their application, storage, transportation, and use, limiting their application in geotechnical excavation projects.

[0003] Rock, as a brittle material, has a tensile strength much lower than its compressive strength. Based on this characteristic, a high-pressure foam expansion fracturing rock-breaking technology is proposed, utilizing the compressibility and high viscosity of gas-liquid two-phase foam. This technology involves instantaneously releasing high-pressure foam into sealed rock expansion pores, causing the rock to fracture under the action of impact stress waves and the quasi-static force of the high-pressure foam. Therefore, it is necessary to design a high-pressure foam expansion fracturing rock-breaking system and its application method to provide support for the research and application of this technology.

[0004] Researchers have designed related mechanical devices for high-pressure foam expansion and rock breaking technology, such as the stamping type and the instantaneous injection type high-pressure foam expansion and rock breaking device ([1] Li Zhiqiang. Design and performance study of high-pressure foam expansion and rock breaking device [D]. China University of Mining and Technology, 2021; [2] Liu Songyong, Cui Song, Gu Congcong. Experimental study on the characteristics of high-pressure foam expansion and rock breaking [J / OL]. Chinese Journal of Geotechnical Engineering, 1-10 [2024-6-24].). However, due to the high compressibility of foam, the foam actually involved in the expansion and rock breaking of the stamping type high-pressure foam expansion and rock breaking device is limited to the foam in the sealed tube. The foam volume is small and it is difficult to effectively expand and break the rock. Although the instantaneous injection type stores a large volume of foam, the release speed of high-pressure foam depends on the opening speed of the high-pressure pneumatic ball valve. The commonly used valve opening speed is too slow, making it difficult to generate impact stress waves inside the rock, and thus difficult to expand and break the rock. Therefore, it is urgent to solve this problem. Summary of the Invention

[0005] To avoid and overcome the technical problems existing in the prior art, this application provides a high-pressure foam expansion and rock-breaking system and its usage method. This application can effectively increase the impact stress wave of foam.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] A high-pressure foam expansion rock-breaking system includes a cylinder body, with a left cylinder cover and a right cylinder cover sealingly covering its left and right ends, respectively. The left cylinder cover has a through-hole connecting to the atmospheric environment. The right cylinder cover has a conical foam outlet, the diameter of which gradually decreases from the inside of the cylinder body to the outside. A foam release pipe, communicating with the foam outlet and used to deliver foam into the rock cavity, is installed on the outside of the right cylinder cover. A piston rod is installed inside the cylinder body, with a pressure adjusting spring compressed between the tail end of the piston rod and the left cylinder cover. The conical front end of the piston rod, under the force of the pressure adjusting spring, is coaxially inserted into the foam outlet and seals it. A piston is dynamically and slidably mounted on the piston rod, and an energy storage spring is compressed between the piston and the left cylinder cover. The piston divides the cylinder cavity into two unconnected chambers; the right chamber is the foam storage chamber, which is connected to the foaming system; the left chamber is the pressure relief chamber, which is connected to the through hole. A limit block is installed on the piston rod, and the limit block is located on the path of the piston moving to the left. When the piston moves to the left, it collides with the limit block to separate the piston rod from the foam outlet. After separation, a flow channel is formed between the piston rod and the foam outlet, connecting the foam storage chamber and the foam release pipe. When the flow channel is formed, the piston moves quickly to the right and puts the pressure relief chamber under negative pressure. The sum of the leftward thrust on the tapered surface at the front end of the piston rod and the negative pressure suction force of the pressure relief chamber on the piston rod is greater than the rightward force of the pressure regulating spring on the piston rod.

[0008] As a further aspect of this application: the sum of the leftward thrust on the tapered surface at the front end of the piston rod and the negative pressure suction force exerted on the piston rod by the pressure relief chamber is F, and the formula for calculating F is as follows:

[0009]

[0010] In the formula, P represents the pressure acting perpendicularly on the tapered surface at the front end of the piston rod during foam release; P x θ represents the component of pressure P along the piston rod axis pointing towards the tail end of the piston rod; θ represents the cone angle of the tapered surface at the front end of the piston rod; P0 represents atmospheric pressure; V0 represents the volume of the pressure relief chamber before the foam outlet opens; V1 represents the volume of the pressure relief chamber after the foam outlet opens; S represents the cross-sectional area of ​​the piston rod.

[0011] As a further aspect of this application: a sliding sleeve is coaxially fitted on the outer side of the piston rod tail, and the sliding sleeve constitutes the limiting block; the tail of the sliding sleeve is a sealed end, and a threaded through hole is coaxially opened on the sealed end; a threaded blind hole two is coaxially opened on the piston rod tail, and the thread direction of the threaded blind hole two is opposite to that of the threaded through hole; the same pressure adjusting screw is threadedly connected to both the threaded blind hole two and the threaded through hole, and the pressure adjusting screw is coaxially inserted in the through hole one; the pressure adjusting spring is compressed between the sliding sleeve and the left cylinder head.

[0012] As a further improvement in this application, the outer diameter of the pressure regulating screw is smaller than the diameter of the through hole, so that a flow gap that allows for ventilation and throttling is formed between the two.

[0013] As a further aspect of this application: a hydraulic sealing device is installed at the front end of the foam release pipe that extends into the rock hole. The hydraulic sealing device includes a rubber sleeve that is sealed on the outside of the foam release pipe. The rubber sleeve and the foam release pipe cooperate to form a high-pressure water chamber. The high-pressure water chamber is connected to a water pump through a two-position three-way solenoid valve. The water pump can inject high-pressure water into the high-pressure water chamber to cause the rubber sleeve to expand circumferentially and seal the rock hole.

[0014] As a further aspect of this application: a left connector and a right connector are coaxially sealed on the outer side of the front end of the foam release tube, and the left connector and the right connector are arranged separately from each other. The left connector is welded and fixed to the foam release tube; the two ends of the rubber sleeve are respectively sealed on the outer side of the left connector and the right connector.

[0015] As a further improvement of this application: a guide hole is provided on the left connector, and the axis of the guide hole is parallel to the axis of the left connector. The guide hole is connected to the water pump through the high-pressure water interface at its front end.

[0016] As a further aspect of this application: the foaming system includes a water tank, a foaming agent tank, and an air pump; the water tank is connected to the water pump, and the output end of the water pump is connected to the input end of the foamer; the foaming agent tank is connected to the foaming agent pump, and the output end of the foaming agent pump is connected to the input end of the foamer; the output end of the air pump is connected to the input end of the foamer; and the output end of the foamer is connected to the foam storage chamber.

[0017] As a further improvement of this application, a one-way valve to prevent backflow is installed on the pipeline connecting the water pump and the foamer, the pipeline connecting the foaming agent pump and the foamer, and the pipeline connecting the air pump and the foamer.

[0018] As a further improvement in this application, a flow meter and a pressure gauge are sequentially installed on the pipeline connecting the foamer and the foam storage chamber.

[0019] A method for using a high-pressure foam expansion rock-breaking system, comprising the following steps:

[0020] a. Drill a hole in the rock surface using a drill bit, insert the hydraulic sealer on the foam release pipe into the rock hole, and ensure that the rubber sleeve is completely placed inside the rock hole;

[0021] b. Turn on the water pump to allow high-pressure water to enter the high-pressure water chamber. The rubber sleeve expands and deforms between the foam release tube and the rock hole to seal the rock hole.

[0022] c. While step b is being performed, turn on the foaming agent pump and air pump, adjust the ratio of water, foaming agent and air, as well as the foam pressure, and fill the foam storage chamber with foam through the foaming device; as the foam pressure in the foam storage chamber gradually increases, the piston is pushed to the left, and at the same time the energy storage spring is compressed, the gas in the pressure relief chamber flows out through the flow gap, and the volume of the pressure relief chamber gradually decreases.

[0023] d. When the piston moves to the left and just collides with the sliding sleeve, the piston drives the sliding sleeve and piston rod to move to the left together, the foam outlet is opened, and the foam flows through the gap and is released into the rock hole through the foam release pipe, and the rock is cracked and broken; at the same time, the water pump, foaming agent pump and air pump are turned off, the foam pressure in the foam storage chamber decreases, and the piston moves to the right.

[0024] e. When the piston gradually moves to the far right, the piston rod moves to the right and resets under the action of the pressure regulating spring, and blocks the foam outlet again, thus closing the foam outlet;

[0025] f. Adjust the two-position three-way solenoid valve. The water in the high-pressure water chamber flows back to the water tank under the action of pressure difference. The rubber sleeve returns to its initial state, and the rock crushing work is completed.

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] Advantages of high-pressure foam expansion rock breaking system:

[0028] 1. This application achieves efficient storage and release of high-pressure foam through a precisely designed structure. Its unique conical foam outlet and piston rod design maintain the foam storage chamber in a sealed state under the action of a pressure regulating spring until the pressure inside the foam storage chamber reaches a preset value, at which point it opens. Once the pressure is sufficient, the piston moves to the left under the action of the foam pressure and collides with the limit block, instantly opening the foam outlet and releasing the high-pressure foam. This foam release method effectively increases the stress wave and quasi-static force generated when the foam impacts the rock pores, allowing the foam expansion force to act instantly within the rock pores, achieving efficient rock crushing. Simultaneously, the internal partitioned cavity design allows the pressure relief chamber to form a negative pressure state during the instantaneous release of foam, further enhancing the suction force on the left side of the piston rod and ensuring rapid foam release.

[0029] 2. At the instant the foam outlet opens, on the one hand, as the high-pressure foam passes through the foam outlet, because the right end face of the piston rod is a conical surface, a portion of the foam pressure acts between the two conical surfaces of the injection gap, creating a leftward thrust on the piston rod and causing it to tend to move to the left. On the other hand, the piston moves rapidly to the right, causing the volume of the pressure relief chamber on the left side of the piston to increase and the air pressure to decrease. The flow clearance between the through hole on the left cylinder head and the pressure regulating screw is small, thus acting as a throttling mechanism. The air pressure in the left-side piston chamber is difficult to recover to atmospheric pressure in a short time. Under the action of negative pressure (below atmospheric pressure) on the left and positive pressure (foam pressure) on the right, the piston rod keeps the foam outlet continuously open, and the high-pressure foam is instantly released into the sealed rock hole, causing the rock to expand and break.

[0030] 3. The sliding sleeve coaxially fitted at the end of the piston rod not only simplifies the structure of the limiting block but also improves the stability and reliability of the system. The sliding sleeve and piston rod are fixed together by a threaded adjusting screw, making the connection more robust. Simultaneously, the adjusting spring is compressed between the sliding sleeve and the left cylinder head, effectively utilizing space and improving the system's compactness. Furthermore, the design of the adjusting screw facilitates adjustment of the sliding sleeve's position, thereby achieving precise control over the foam release opening pressure.

[0031] 4. The design of the outer diameter of the pressure regulating screw being smaller than the diameter of the through hole one creates a flow gap that allows for ventilation and throttling. This not only ensures smooth ventilation in the pressure relief chamber but also avoids abnormal pressure in the pressure relief chamber caused by the pressure regulating screw completely blocking the through hole one.

[0032] 5. The hydraulic sealing device installed at the front end of the foam release pipe injects high-pressure water into the high-pressure water chamber between the rubber sleeve and the foam release pipe, causing the rubber sleeve to expand circumferentially and seal the rock hole. The use of the hydraulic sealing device simplifies the operation process and reduces the labor intensity of workers.

[0033] 6. The design of the left and right connectors allows the rubber sleeve to be securely and tightly sealed to the outside of the foam release tube, improving the system's sealing performance and preventing foam leakage due to loose rubber sleeves. Simultaneously, the separate arrangement of the left and right connectors facilitates the formation of the high-pressure water chamber.

[0034] 7. The guide hole on the left connector allows high-pressure water to smoothly enter the high-pressure water chamber, thereby driving the rubber sleeve to expand and deform. This not only improves the response speed of the hydraulic sealer, but also ensures that the high-pressure water can be evenly distributed on the entire rubber sleeve, thus improving the sealing effect.

[0035] 8. The foaming system, through the cooperation of a water tank, foaming agent tank, and air pump, achieves precise control over foam pressure, gas-liquid ratio, and flow rate. This not only improves foam quality but also ensures that foam is stably filled into the foam storage chamber. Simultaneously, the system's internal one-way valve design prevents backflow issues, enhancing system stability and reliability.

[0036] 9. The flow meter and pressure gauge installed sequentially on the pipeline connecting the foamer and the foam storage chamber can monitor the flow rate and pressure status of the foam in real time. This not only provides accurate data support for the system, but also facilitates the staff to adjust the system parameters in a timely manner to ensure the optimal working condition of the system.

[0037] 10. This method of use provides detailed step-by-step instructions to ensure the correct operation and use of the high-pressure foam expansion rock breaking system. Each step, from drilling, sealing, foam filling to foam release and recovery, is explained in detail, improving work efficiency and reducing operational difficulty and risk. At the same time, this method also emphasizes the system's safety and stability, ensuring the smooth progress of rock breaking operations. Attached Figure Description

[0038] Figure 1 This is an overall layout diagram of a high-pressure foam expansion and cracking rock breaking system provided in an embodiment of this application.

[0039] Figure 2 This is a three-dimensional overall view of the high-pressure foam expansion and rock-breaking device in the embodiments of this application.

[0040] Figure 3 This is a structural diagram of the high-pressure foam storage system in an embodiment of this application.

[0041] Figure 4 This is a structural diagram of the foam release pressure regulating system in an embodiment of this application.

[0042] Figure 5 This is a structural diagram of the hydraulic sealing device in an embodiment of this application.

[0043] Figure 6 This is a layout diagram of the foaming system in an embodiment of this application.

[0044] Figure 7 for Figure 1 Schematic diagram of medium- and high-pressure foam energy storage.

[0045] Figure 8 for Figure 1 Schematic diagram of medium- and high-pressure foam release status.

[0046] In the diagram: 1. Cylinder block; 1-1. Left cylinder head; 1-2. Right cylinder head; 1-3. Bolt; 1-4. Foam storage chamber; 1-5. Threaded blind hole one; 1-6. Foam outlet; 1-7. Foam inlet; 1-8. Through hole one; 2. Energy storage spring; 3. Piston; 3-1. Through hole two; 4. Foam release pipe; 4-1. Screw; 5. Hydraulic sealer; 5-1. Left connector; 5-2. Rubber sleeve; 5-3. Right connector; 5-4. High 5-5. High-pressure water interface; 6. Two-position three-way solenoid valve; 7. Foaming system; 7-1. Check valve; 7-2. Flow meter; 7-3. Foamer; 7-4. Water pump; 7-5. Water tank; 7-6. Foaming agent tank; 7-7. Foaming agent pump; 7-8. Air pump; 7-9. Pressure gauge; 8. Piston rod; 8-1. Pressure adjusting screw; 8-2. Pressure adjusting spring; 8-3. Sliding sleeve; 8-4. Threaded blind hole two; 8-5. Threaded through hole. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] like Figure 1 and Figure 2 As shown, a high-pressure foam expansion and rock-breaking system includes a high-pressure foam storage system, a foam release and pressure regulation system, a hydraulic sealing device 5, and a foaming system 7.

[0049] like Figure 3 As shown, the high-pressure foam storage system includes a cylinder 1, an energy storage spring 2, a piston 3, a left cylinder head 1-1, and a right cylinder head 1-2. The cylinder 1 is a hollow cylinder, with the left cylinder head 1-1 and the right cylinder head 1-2 connected to its left and right sides respectively. The left cylinder head 1-1 and the right cylinder head 1-2 are connected and fixed by four sets of bolts 1-3. A through hole 1-8 for installing a pressure regulating screw 8-1 is provided at the central axis of the left cylinder head 1-1. The inner diameter of the through hole 1-8 is slightly larger than the outer diameter of the pressure regulating screw 8-1, creating a flow gap between the pressure regulating screw 8-1 and the through hole 1-8 to facilitate gas entry and exit from the cylinder 1. A trumpet-shaped foam outlet 1-6 is provided at the central axis of the right cylinder head 1-2. A foam inlet 1-7 and four threaded blind holes 1-5 for connecting to the foam release pipe 4 are also provided on the right side of the right cylinder head 1-2. Piston 3 is located inside cylinder 1, and an energy storage spring 2 is compressed between piston 3 and left cylinder head 1-1. The space between piston 3 and right cylinder head 1-2 forms a foam storage cavity 1-4, and a through hole 3-1 for coaxial dynamic sealing of piston rod 8 is provided at the central axis of piston 3.

[0050] like Figure 4 As shown, the foam release pressure regulating system includes a piston rod 8, a pressure regulating screw 8-1, a pressure regulating spring 8-2, and a sliding sleeve 8-3. The right end of the piston rod 8 is machined into a tapered shape to fit against the foam outlet 1-6 to seal it. A threaded blind hole 8-4 for connecting the pressure regulating screw 8-1 is provided at the central axis of the left side of the piston rod 8. A sliding sleeve 8-3 is also connected to the left side of the piston rod 8, and the sliding sleeve 8-3 is coaxially arranged with the piston rod 8. A threaded through hole 8-5 is provided at the central axis of the sliding sleeve 8-3. The thread direction in the threaded through hole 8-5 is opposite to the thread direction in the threaded blind hole 8-4. The pressure regulating spring 8-2 is compressed and installed at the left end of the sliding sleeve 8-3, and the left end of the pressure regulating spring 8-2 is mounted on the right end face of the left cylinder head 1-1. The pressure regulating screw 8-1 passes through the through hole 1-8 on the left cylinder head 1-1 and is threadedly connected to the threaded through hole 8-5 on the sliding sleeve 8-3 and the threaded blind hole 8-4 on the piston rod 8. The sliding sleeve 8-3 can slide along the axial direction of the piston rod 8 within a certain distance range under the action of the pressure regulating screw 8-1.

[0051] like Figure 5 and Figure 6 As shown, the hydraulic sealing device 5 includes a left connector 5-1, a rubber sleeve 5-2, a right connector 5-3, and a high-pressure water interface 5-5. The left connector 5-1 is fixed to the outside of the foam release pipe 4 by welding, and the right connector 5-3 is located on the outside of the foam release pipe 4. The right connector 5-3 can slide dynamically along the axial direction of the foam release pipe 4. The left and right ends of the rubber sleeve 5-2 are tightly pressed onto the left connector 5-1 and the right connector 5-3, respectively, forming a sealed high-pressure water chamber 5-4 between the rubber sleeve 5-2 and the foam release pipe 4. A high-pressure water interface 5-5 is located on the left side of the left connector 5-1, which communicates with the high-pressure water chamber 5-4. The high-pressure water interface 5-5 is connected to a two-position three-way solenoid valve 6, which is connected to a water pump 7-4 through a one-way valve 7-1.

[0052] like Figure 6 As shown, the foaming system 7 includes a water tank 7-5, a foaming agent tank 7-6, a water pump 7-4, a foaming agent pump 7-7, an air pump 7-8, and a foamer 7-3. One end of the water pump 7-4 is connected to the water tank 7-5, and the other end of the water pump 7-4 is connected to the foamer 7-3 through a one-way valve 7-1. The foaming agent tank 7-6 contains surfactants and is connected to the foaming agent pump 7-7. The foaming agent pump 7-7 and the air pump 7-8 are respectively connected to the foamer 7-3 through one-way valves 7-1. Water, foaming agent, and air are fully mixed in the foamer 7-3 to form high-pressure foam. The foamer 7-3 is then connected in sequence to a flow meter 7-2, a one-way valve 7-1, and a pressure gauge 7-9, and finally connected to the foam inlet 1-7.

[0053] like Figure 1 and Figure 4 As shown, the pressure regulating principle of the foam release pressure regulating system is as follows: Since the threaded through hole 8-5 on the sliding sleeve 8-3 and the threaded blind hole 8-4 on the piston rod 8 have opposite thread directions, and a limit pin is provided on the sliding sleeve 8-3, the distance between the sliding sleeve 8-3 and the piston rod 8 can be changed by rotating the pressure regulating screw 8-1, thereby adjusting the relative position of the piston 3 when it moves to the left and just contacts the sliding sleeve 8-3. Since the foam pressure is different at different positions of the piston 3, the maximum bursting pressure during foam release can be changed by adjusting the position of the piston 3 when the foam outlet 1-6 is opened, thus allowing the foam bursting pressure to be adjusted for different working conditions.

[0054] like Figure 7 As shown, the diameter of the rock hole is no more than 5 mm larger than the outer diameter of the hydraulic sealing device 5. Figure 6 As shown, the foam air volume fraction produced by the foamer 7-3 ranges from 50% to 95%.

[0055] like Figure 2 As shown, the left end of the foam release tube 4 is fixed to the threaded blind hole 8-4 on the right cylinder head 1-2 by four screws 4-1.

[0056] Assuming the increase in volume of the pressure relief chamber on the left side of piston 3 is an instantaneous adiabatic process, ignoring the gas flowing in through the through-hole 1-8, and ignoring the volume occupied by the irregular cavity structure and pressure regulating structure, the foam pressure and the negative pressure of the pressure relief chamber exert a leftward thrust F on the piston rod. The formula for calculating F is shown in formula (1):

[0057]

[0058] In the formula, P represents the pressure acting perpendicularly on the tapered surface at the front end of the piston rod 8 during foam release; P x θ represents the component of pressure P along the axial direction of piston rod 8 pointing towards the tail end of piston rod 8; θ represents the cone angle of the tapered surface at the front end of piston rod 8; P0 represents atmospheric pressure; V0 represents the volume of foam storage chamber 1-4 before foam outlet 1-6 is opened; V1 represents the volume of foam storage chamber 1-4 after foam outlet 1-6 is opened; S represents the cross-sectional area of ​​piston rod 8.

[0059] Assuming that at the instant foam outlets 1-6 open, the foam release pressure P is 15 MPa, piston 3 moves 20 mm to the right, the air pressure in the pressure relief chamber is 80 kPa, and the diameter of piston rod 8 is 40 mm, then the thrust F at this moment is approximately 1.3 × 10⁻⁶. 4 N.

[0060] When foam outlet 1-6 is closed, pressure regulating spring 8-2 is slightly compressed, exerting a force to the right on piston rod 8 to seal foam outlet 1-6. The initial length of pressure regulating spring 8-2 is 60mm. The formula for calculating the elastic force of pressure regulating spring 8-2 is shown in formula (2):

[0061] F k =k·x (2)

[0062] In the formula, k is the elastic coefficient of the pressure regulating spring 8-2, and x is the displacement of the pressure regulating spring 8-2.

[0063] The spring constant of the pressure regulating spring 8-2 is 50 N / m, and its length is 50 mm when the foam outlet 1-6 is closed. At the instant the foam outlet 1-6 opens, assuming the pressure regulating spring 8-2 continues to compress by 10 mm, its spring force will be 10 N. Since the thrust F at this moment is much greater than the spring force F of the pressure regulating spring 8-2... k Therefore, foam outlets 1-6 can be kept open continuously.

[0064] As the foam is released, assuming the foam pressure drops to 3 MPa, the pressure in the pressure relief chamber drops to 20 kPa. At this point, the thrust F is approximately 2665 N, which is still greater than the spring force F of the pressure regulating spring 8-2. k Foam outlets 1-6 can still be opened, thus enabling continuous foam output.

[0065] The detailed steps and working principle of a high-pressure foam expansion rock-breaking system are as follows:

[0066] a. First, drill a hole in the rock surface using a drill bit, and insert the hydraulic sealer 5 of the high-pressure foam expansion rock breaking device into the rock hole, ensuring that the rubber sleeve 5-2 of the hydraulic sealer 5 is completely placed inside the rock hole.

[0067] b, such as Figure 7 As shown, turn on the water pump 7-4 and control the direction of the two-position three-way solenoid valve 6 to ensure that high-pressure water enters the high-pressure water chamber 5-4 of the hydraulic sealing device 5. The rubber sleeve 5-2 expands and deforms in the limited space between the foam release pipe 4 and the rock hole until the rubber sleeve 5-2 tightly fits the inner wall of the rock hole, thereby achieving a seal on the rock hole.

[0068] c. While step b is being performed, open the foaming agent pump 7-7 and the air pump 7-8, adjust the ratio of water, foaming agent, and air, and the foam pressure. As the foam pressure in the foam storage chamber 1-4 gradually increases, the piston 3 is slowly pushed to the left. Figure 7As shown, the elastic potential energy of the energy storage spring 2 continuously increases, while the volume of the left cavity of the piston 3 gradually decreases. Due to the flow gap between the through hole 1-8 on the left cylinder head 1-1 and the pressure regulating screw 8-1, the air in the left cavity of the piston 3 is slowly released to the external environment through this gap.

[0069] d. For example Figure 8 As shown, when piston 3 moves to the left and just contacts sliding sleeve 8-3, since sliding sleeve 8-3 and piston rod 8 are fixed by the thread on pressure adjusting screw 8-1, piston 3 drives sliding sleeve 8-3 and piston rod 8 to move to the left together, and foam outlet 1-6 is opened. At this time, water pump 7-4, foaming agent pump 7-7 and air pump 7-8 are turned off, and the foam pressure in foam storage chamber 1-4 drops rapidly, and piston 3 moves quickly to the right. On the one hand, when high-pressure foam passes through foam outlet 1-6, since the right end face of piston rod 8 is a conical surface, part of the foam pressure acts between the two conical surfaces of the spray gap, forming a leftward thrust on piston rod 8 and causing piston rod 8 to tend to move to the left. On the other hand, the rapid rightward movement of piston 3 causes the volume of the left cavity of piston 3 to increase and the air pressure to decrease. The flow gap between the through hole 1-8 on the left cylinder head 1-1 and the pressure regulating screw 8-1 is small, which plays a throttling role. The air pressure in the left cavity of piston 3 is difficult to recover to atmospheric pressure in a short time. Under the action of negative pressure on the left (lower than atmospheric pressure) and positive pressure on the right (foam pressure), piston rod 8 keeps foam outlet 1-6 continuously open. High-pressure foam is released instantly into the sealed rock hole, and the rock is cracked and broken.

[0070] e. As the sliding sleeve 8-3 and piston rod 8 move to the left in step d, the pressure regulating spring 8-2 is compressed. When the high-pressure foam is released and the piston 3 moves to the rightmost side, the foam pressure acting on the right cone surface of the piston rod 8 gradually decreases. At the same time, the air pressure in the left cavity of the piston 3 gradually increases. Under the action of the pressure regulating spring 8-2, the piston rod 8 slowly moves to the right to reset. The right cone surface of the piston rod 8 is tightly fitted with the foam outlet 1-6 on the right cylinder head 1-2, and the foam outlet 1-6 is closed.

[0071] f. Control the direction of the two-position three-way solenoid valve 6 to release the high-pressure water in the hydraulic sealing device 5 into the water tank 7-5, and restore the rubber sleeve 5-2 to its initial state;

[0072] g. Repeat step af to complete the rock crushing process.

[0073] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and inventive concept of this application, should be included within the scope of protection of this application.

Claims

1. A high-pressure foam expansion and rock-breaking system, characterized in that, The cylinder includes a cylinder body (1), with a left cylinder cover (1-1) and a right cylinder cover (1-2) respectively sealing the left and right ends of the cylinder body (1). The left cylinder cover (1-1) has a through hole (1-8) for connecting to the atmospheric environment. The right cylinder cover (1-2) has a conical foam outlet (1-6) that passes through it. The diameter of the foam outlet (1-6) gradually decreases from the inside of the cylinder body (1) outwards, and the outside of the right cylinder cover (1-2) is equipped with a device that communicates with the foam outlet (1-6) and is used for... A foam release pipe (4) is used to deliver foam into a rock hole; a piston rod (8) is installed inside the cylinder (1), and a pressure regulating spring (8-2) is compressed between the tail end of the piston rod (8) and the left cylinder head (1-1). The conical front end of the piston rod (8) is coaxially inserted into the foam outlet (1-6) under the action of the spring force of the pressure regulating spring (8-2), and the foam outlet (1-6) is blocked; a piston (3) is dynamically and slidably installed on the piston rod (8), and the piston (3) is connected to the left cylinder head (1-1). A storage spring (2) is compressed between the piston (3) and the piston (3) divides the inner cavity of the cylinder (1) into two non-communicating cavities; the right cavity is a foam storage cavity (1-4), and the foam storage cavity (1-4) is connected to the foaming system (7); the left cavity is a pressure relief cavity connected to the through hole (1-8); a limit block is installed on the piston rod (8), and the limit block is located on the path of the piston (3) moving to the left, so that the piston (3) can collide with the limit block when moving to the left to make the piston (3) move to the left. The piston rod (8) and the foam outlet (1-6) are separated from each other. After separation, the piston rod (8) and the foam outlet (1-6) form a flow channel connecting the foam storage chamber (1-4) and the foam release pipe (4). When the flow channel is generated, the piston (3) moves quickly to the right and puts the pressure relief chamber under negative pressure. The sum of the leftward thrust on the tapered surface at the front end of the piston rod (8) and the negative pressure suction force of the pressure relief chamber on the piston rod (8) is greater than the rightward force of the pressure regulating spring (8-2) on the piston rod (8).

2. The high-pressure foam expansion and rock-breaking system according to claim 1, characterized in that, The sum of the leftward thrust on the tapered surface at the front end of the piston rod (8) and the negative pressure suction force exerted on the piston rod (8) by the pressure relief chamber is: , The calculation formula is as follows: ； In the formula, This indicates the pressure acting vertically on the tapered surface at the front end of the piston rod (8) during foam release; Indicates pressure The component of the force along the piston rod (8) axially points towards the tail end of the piston rod (8); This indicates the cone angle of the tapered surface at the front end of the piston rod (8); Indicates atmospheric pressure; This indicates the volume of the pressure relief chamber before the foam outlet (1-6) is opened; This indicates the volume of the pressure relief chamber after the foam outlet (1-6) is opened; This represents the cross-sectional area of ​​the piston rod (8).

3. The high-pressure foam expansion and rock-breaking system according to claim 2, characterized in that, A sliding sleeve (8-3) is coaxially sleeved on the outer side of the piston rod (8) tail, and the sliding sleeve (8-3) constitutes the limiting block; the tail of the sliding sleeve (8-3) is a sealed end, and a threaded through hole (8-5) is coaxially opened on the sealed end; a threaded blind hole (8-4) is coaxially opened on the tail of the piston rod (8), and the thread direction of the threaded blind hole (8-4) is opposite to that of the threaded through hole (8-5); the same pressure regulating screw (8-1) is threadedly connected to the threaded blind hole (8-4) and the threaded through hole (8-5), and the pressure regulating screw (8-1) is coaxially inserted in the through hole (1-8); the pressure regulating spring (8-2) is compressed between the sliding sleeve (8-3) and the left cylinder head (1-1); the outer diameter of the pressure regulating screw (8-1) is smaller than the diameter of the through hole (1-8) so that a ventilated and throttling flow gap is formed between the two.

4. The high-pressure foam expansion and rock-breaking system according to claim 3, characterized in that, A hydraulic sealer (5) is installed at the front end of the foam release pipe (4) that extends into the rock hole. The hydraulic sealer (5) includes a rubber sleeve (5-2) that is sealed on the outside of the foam release pipe (4). The rubber sleeve (5-2) and the foam release pipe (4) cooperate to form a high-pressure water chamber (5-4). The high-pressure water chamber (5-4) is connected to the water pump (7-4) through a two-position three-way solenoid valve (6). The water pump (7-4) can inject high-pressure water into the high-pressure water chamber (5-4) so ​​that the rubber sleeve (5-2) expands circumferentially to seal the rock hole.

5. The high-pressure foam expansion and rock-breaking system according to claim 4, characterized in that, The front end of the foam release tube (4) is coaxially sealed with a left connector (5-1) and a right connector (5-3), and the left connector (5-1) and the right connector (5-3) are arranged separately from each other. The left connector (5-1) is welded and fixed to the foam release tube (4). The two ends of the rubber sleeve (5-2) are respectively sealed on the outside of the left connector (5-1) and the right connector (5-3).

6. The high-pressure foam expansion and rock-breaking system according to claim 5, characterized in that, A guide hole is provided on the left connector (5-1), and the axis of the guide hole is parallel to the axis of the left connector (5-1). The guide hole is connected to the water pump (7-4) through the high-pressure water interface (5-5) at its front end.

7. A high-pressure foam expansion and rock-breaking system according to claim 6, characterized in that, The foaming system (7) includes a water tank (7-5), a foaming agent tank (7-6), and an air pump (7-8); the water tank (7-5) is connected to the water pump (7-4), and the output end of the water pump (7-4) is connected to the input end of the foamer (7-3); the foaming agent tank (7-6) is connected to the foaming agent pump (7-7), and the output end of the foaming agent pump (7-7) is connected to the input end of the foamer (7-3); the output end of the air pump (7-8) is connected to the input end of the foamer (7-3); and the output end of the foamer (7-3) is connected to the foam storage chamber (1-4).

8. A high-pressure foam expansion and rock-breaking system according to claim 7, characterized in that, A one-way valve (7-1) to prevent backflow is installed on the pipeline connecting the water pump (7-4) and the foamer (7-3), the pipeline connecting the foaming agent pump (7-7) and the foamer (7-3), and the pipeline connecting the air pump (7-8) and the foamer (7-3).

9. A high-pressure foam expansion and rock-breaking system according to claim 8, characterized in that, A flow meter (7-2) and a pressure gauge (7-9) are installed sequentially on the pipeline connecting the foamer (7-3) and the foam storage chamber (1-4).

10. A method of using a high-pressure foam expansion rock-breaking system, wherein the method applies the high-pressure foam expansion rock-breaking system as described in claim 7, characterized in that... The following usage steps are included: a. Drill a hole in the rock surface using a drill bit, insert the hydraulic sealer (5) on the foam release pipe (4) into the rock hole, and place the rubber sleeve (5-2) completely inside the rock hole; b. Turn on the water pump (7-4) to allow high-pressure water to enter the high-pressure water chamber (5-4). The rubber sleeve (5-2) expands and deforms between the foam release pipe (4) and the rock hole to seal the rock hole. c. While step b is being performed, the foaming agent pump (7-7) and air pump (7-8) are turned on to adjust the ratio of water, foaming agent and air, as well as the foam pressure. Foam is then injected into the foam storage chamber (1-4) through the foaming device (7-3). As the foam pressure in the foam storage chamber (1-4) gradually increases, the piston (3) is pushed to the left, and the energy storage spring (2) is compressed. The gas in the pressure relief chamber flows out through the flow gap, and the volume of the pressure relief chamber gradually decreases. d. When the piston (3) moves to the left and just collides with the sliding sleeve (8-3), the piston (3) drives the sliding sleeve (8-3) and the piston rod (8) to move to the left together, the foam outlet (1-6) is opened, and the foam flows through the gap through the foam release pipe (4) and is released into the rock hole, and the rock is cracked and broken; at the same time, the water pump (7-4), the foaming agent pump (7-7) and the air pump (7-8) are turned off, the foam pressure in the foam storage chamber (1-4) decreases, and the piston (3) moves to the right; e. When the piston (3) moves to the far right, the piston rod (8) moves to the right and resets under the action of the pressure regulating spring (8-2), and blocks the foam outlet (1-6) again, and the foam outlet (1-6) is closed. f. Adjust the two-position three-way solenoid valve (6). The water in the high-pressure water chamber (5-4) flows back to the water tank (7-5) under the action of pressure difference. The rubber sleeve (5-2) returns to its initial state, and the rock crushing work is completed.

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