Double-fluid grouting reverse stopping structure of shield machine

Abstract

The shield tunneling machine dual-slurry injection anti-reverse structure provided by this invention includes a diversion block fixed inside the rear shield shell plate. The diversion block has a flow channel connecting liquid hole A and liquid pipe B. By making the flow channel pass through both ends of the diversion block along its length, the flow channel includes coaxially arranged inlet and outlet sections, as well as multiple annular flow channels connected in series between the inlet and outlet sections. Each annular flow channel includes an inclined section and a semi-annular section bypassing both ends of the inclined section. The inclined sections of adjacent annular flow channels have opposite inclination directions, and the semi-annular sections of adjacent annular flow channels are located on both sides of the axis of the inlet section, making the semi-annular sections teardrop-shaped. This allows the flow channel to form a Tesla flow channel with anti-reverse function, thus taking into account both diversion and anti-reverse functions. The structure is simple, has low manufacturing cost, high structural strength, can resist the impact of propulsion cylinder support shoes, is easy to disassemble and assemble, and has stronger buffering effect of anti-reverse effect, which can reduce the probability of blockage. After blockage, multiple methods can be used to clear it, and the handling flexibility is better.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine technology, specifically to a double-slurry injection anti-reverse structure for tunnel boring machines. Background Technology

[0002] In recent years, with the increasing number of tunnel boring machine (TBM) projects, the geological conditions encountered have become more and more complex and changeable, and the need for synchronous dual-liquid grouting has also increased.

[0003] Most commonly used two-component grouting methods are as follows: Figure 1 As shown, liquid A is delivered through liquid A hole 2 on the rear shield shell plate 1, while liquid B is delivered through liquid B pipe 3 fixed inside the rear shield shell plate 1 and communicating with liquid A hole 2. The two are mixed at the position in front of the shield tail brush on the rear shield shell. A guide block 4 is provided at the mixing point to guide liquid B into liquid A hole 2. A one-way valve 5 is provided at the connection between liquid B pipe 3 and guide block 4 to prevent liquid A from flowing back to liquid B pipe 3 through guide block 4. Although this structure can solve the problem of liquid A flowing back to liquid B pipe 3, it has problems in at least the following aspects:

[0004] 1. The height of the one-way valve cannot exceed the height of the rear guide bar (usually 30mm). Its external valve body and internal check plate are relatively small and need to be specially made, resulting in high manufacturing costs.

[0005] 2. Relying solely on the interface connection results in low structural strength, making it susceptible to damage from impacts with the propulsion cylinder support shoes during tunneling. Furthermore, due to the limited installation space, disassembly and reassembly after damage are difficult, and replacement is not easy.

[0006] 3. When the injection pressure of the dual-slurry is unstable, liquid A and liquid B are prone to mix and solidify at the connection between the guide block and the liquid A hole, forming a blockage. Alternatively, liquid A may flow backward and enter the guide block in the opposite direction, mixing and solidifying with the residual liquid B inside the guide block, forming a blockage. Such blockages are difficult to flush out by simply pumping water. It is necessary to stop the machine and disassemble the guide block for manual cleaning, which is complicated and has high maintenance costs.

[0007] In summary, all the problems are concentrated on the combined structure of the guide block and the check valve. This structure serves both to guide the mixing of liquids A and B and to prevent backflow. However, these two functions are achieved separately by the guide block and the check valve, and they cannot achieve commonality. Summary of the Invention

[0008] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a double-slurry injection anti-reverse structure for tunnel boring machines.

[0009] To achieve the above objectives, the technical solution provided by this invention is a double-slurry injection anti-reverse structure for a tunnel boring machine, comprising a diversion block fixed inside the rear shield shell plate. The diversion block has a flow channel connecting liquid hole A and liquid pipe B. The flow channel penetrates both ends of the diversion block along its length. The flow channel includes an inlet section and an outlet section arranged coaxially, as well as multiple annular flow channels connected in series between the inlet section and the outlet section. Each annular flow channel includes an inclined section and a semi-annular section bypassing both ends of the inclined section. The inclined sections of adjacent annular flow channels have opposite inclination directions. The semi-annular sections of adjacent annular flow channels are located on both sides of the axis of the inlet section. The semi-annular sections are teardrop-shaped, making the flow channel a Tesla flow channel with anti-reverse function.

[0010] Preferably, the inlet section has a first interface at the opening on the end face of the drainage block, the first interface being used to connect the B liquid pipe, the outlet section has a second interface at the opening on the end face of the drainage block, the second interface having a removable plug, and the flow channel further includes a mixing hole that is perpendicularly connected to the outlet section, the mixing hole penetrating the outer side of the drainage block and communicating with the A liquid hole.

[0011] More preferably, the mixing hole is located near the connection between the outlet section and the annular flow channel.

[0012] More preferably, the first interface and the second interface have the same specifications.

[0013] Preferably, the outer side of the diversion block is provided with a positioning boss. When the diversion block is fixed to the inner side of the rear shield shell plate, the positioning boss is embedded in the positioning groove on the rear shield shell plate, and the mixing hole passes through the positioning boss.

[0014] More preferably, the positioning boss is waist-shaped.

[0015] More preferably, the outer side of the drainage block is provided with an annular groove surrounding the positioning boss, and an O-ring is provided in the annular groove.

[0016] Preferably, the flow guide block is composed of two plates joined together, and the flow channels are symmetrically distributed along the joining surface of the two plates. After joining, the two plates are connected as one unit by watertight welding.

[0017] More preferably, the plate body is also provided with threaded holes, and there are multiple threaded holes symmetrically distributed on both sides of the flow channel.

[0018] Preferably, there are at least four annular flow channels, and the total length of the inlet section and the outlet section accounts for no more than 25% of the length of the guide block.

[0019] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0020] The shield tunneling machine dual-slurry injection anti-reverse structure provided by this invention includes a diversion block fixed inside the rear shield shell plate. The diversion block has a flow channel connecting liquid hole A and liquid pipe B. By making the flow channel pass through both ends of the diversion block along its length, the flow channel includes an inlet section and an outlet section arranged coaxially, as well as multiple annular flow channels connected in series between the inlet section and the outlet section. Each annular flow channel includes an inclined section and a semi-annular section bypassing both ends of the inclined section. The inclined sections of adjacent annular flow channels have opposite inclination directions, and the semi-annular sections of adjacent annular flow channels are located on both sides of the axis of the inlet section, making the semi-annular sections teardrop-shaped. This allows the flow channel to form a Tesla flow channel with anti-reverse function, thus taking into account both diversion and anti-reverse functions. The structure is simple, has low manufacturing cost, high structural strength, can resist the impact of propulsion cylinder support shoes, is easy to disassemble and assemble, and has stronger buffering effect of anti-reverse effect, which can reduce the probability of blockage. After blockage occurs, multiple methods can be used to clear it, and the handling flexibility is better. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the existing technology of a drainage block combined with a one-way valve, with a partial cross-section view.

[0022] Figure 2 This is a schematic diagram of a preferred embodiment of the present invention, with a partial cross-sectional view.

[0023] Figure 3 yes Figure 2 A diagram showing the view from the right.

[0024] Figure 4 yes Figure 3 A schematic diagram of the central drainage block.

[0025] Figure 5 yes Figure 3 Rear view of the central drainage block.

[0026] Figure 6 yes Figure 3 Side view of the drainage block.

[0027] The components are: 1. Rear shield shell plate; 2. A liquid hole; 3. B liquid pipe; 4. Guide block; 5. One-way valve; 6. Positioning groove; 10. Drain block; 11. Positioning boss; 12. Annular groove; 13. O-ring seal; 14. Plate body; 141. Threaded hole; 20. Flow channel; 21. Inlet section; 211. First interface; 22. Outlet section; 221. Second interface; 222. Plug; 23. Annular flow channel; 231. Inclined section; 232. Semi-annular section; 24. Mixing hole. Detailed Implementation

[0028] like Figures 2 to 6 As shown, the shield machine dual-slurry injection anti-reverse structure provided by the present invention includes a diversion block 10 fixed inside the rear shield shell plate 1. The diversion block 10 is provided with a flow channel 20 connecting liquid hole A 2 and liquid pipe B 3. The flow channel 20 penetrates both ends of the diversion block 10 in the length direction. The flow channel 20 includes an inlet section 21 and an outlet section 22 arranged coaxially, and a plurality of annular flow channels 23 connected in series between the inlet section 21 and the outlet section 22. Each annular flow channel 23 includes an inclined section 231 and a semi-annular section 232 bypassing both ends of the inclined section 231. The inclined sections 231 of adjacent annular flow channels 23 have opposite inclination directions. The semi-annular sections 232 of adjacent annular flow channels 23 are respectively located on both sides of the axis of the inlet section 21. The semi-annular sections 232 are teardrop-shaped, so that the flow channel 20 constitutes a Tesla flow channel with anti-backflow function, thus taking into account both the functions of diversion and anti-backflow. The structure is simple, the manufacturing cost is low, the structural strength is high, and it can resist the impact of the propulsion cylinder support shoe. It is easy to disassemble and assemble, and the anti-backflow effect has stronger buffering, which can reduce the probability of blockage. After blockage occurs, various methods can be used to clear it, and the handling is more flexible.

[0029] In this embodiment, the inlet section 21 has a first interface 211 at the opening on the end face of the diversion block 10. The first interface 211 is used to connect the B liquid pipe 3. The outlet section 22 has a second interface 221 at the opening on the end face of the diversion block 10. The second interface 221 is provided with a removable plug 222. The flow channel 20 also includes a mixing hole 24 that is perpendicularly connected to the outlet section 22. The mixing hole 24 penetrates the outer side of the diversion block 10 and is connected to the A liquid hole 2.

[0030] The advantage of this setup is that it can increase the difficulty of backflow of liquid A by utilizing the vertical connection between the mixing hole and the outlet section. In the event of a blockage in the flow channel, the plug can be removed, and high-pressure water can be connected through the liquid B pipe to flush the blockage from the second interface. After flushing, the plug can be reinstalled, and high-pressure water can be used to flush the blockage in the mixing hole to achieve unblocking.

[0031] In this embodiment, the mixing hole 24 is located near the connection between the outlet section 22 and the annular flow channel 23, and is spaced apart from the plug 222. At the same time, the first interface 211 and the second interface 221 have the same specifications. The advantage of this arrangement is that when a long blockage occurs in the flow channel, which is difficult to clear with high-pressure water through the B liquid pipe in a short time, and the dual-liquid grouting cannot be stopped, the plug can be removed, and the B liquid pipe connected to the high-pressure water pipe can be reversed to the second interface. The blockage in the mixing hole can be cleared with high-pressure water. Then, the B liquid pipe can be replaced with B liquid, and B liquid can be injected into the A liquid hole in the manner of B liquid pipe → second interface → mixing hole to maintain the dual-grouting effect. When the conditions are met, the B liquid pipe can be replaced with the first interface, and high-pressure water can be used to clear the blockage in the flow channel.

[0032] In this embodiment, the outer side of the drainage block 10 (the side facing the A liquid hole) is provided with a positioning boss 11. The positioning boss 11 is waist-shaped. When the drainage block 10 is fixed to the inner side of the rear shield shell plate 1, the positioning boss 11 is embedded in the positioning groove 6 on the rear shield shell plate 1. The mixing hole 24 passes through the positioning boss 11. To improve the sealing effect, the outer side of the drainage block 10 is further provided with an annular groove 12 surrounding the positioning boss 11. An O-ring 13 is provided in the annular groove 12. Furthermore, the positioning groove 6 is a countersunk groove. When the drainage block 10 is fixed to the inner side of the rear shield shell plate 1, a part of the drainage block 10 is embedded in the countersunk groove.

[0033] To facilitate processing and connection, in this embodiment, the flow block 10 is composed of two plates 14 joined together. The flow channel 20 is symmetrically distributed along the joint surface of the two plates 14. After joining, the two plates 14 are connected as one unit by watertight welding. The plates 14 are also provided with threaded holes 141. There are multiple threaded holes 141 and they are symmetrically distributed on both sides of the flow channel 20.

[0034] To ensure the backflow prevention effect and facilitate the clearing of blockages, there are at least four annular flow channels 23. The total length of the inlet section 21 and the outlet section 22 accounts for no more than 25% of the length of the diversion block 10. In this embodiment, there are four annular flow channels 23, and the total length of the inlet section 21 and the outlet section 22 accounts for 20% of the length of the diversion block 10.

[0035] The following describes the usage status of the dual-slurry injection anti-reverse structure of the tunnel boring machine.

[0036] [1] During normal operation, liquid A flows backward through liquid A hole, and liquid B enters the flow channel in the diversion block through liquid B hose. Since it is a positive flow (from the inlet section to the outlet section), the flow of liquid will not be obstructed according to the characteristics of the Tesla flow channel. Liquid B can smoothly enter liquid A hole through the mixing hole of the flow channel and mix with liquid A. The mixed liquid after mixing flows along the liquid A hole in the rear half of the tail shield to achieve dual-liquid grouting.

[0037] [2] When only single-liquid grouting is needed or the pressure of double-liquid grouting is unstable, causing the pressure of liquid A to be greater than that of liquid B, since the pipelines of liquids A and B are connected, liquid A will flow back into the pipe of liquid B. However, due to the characteristics of the Tesla flow channel, the pressure of the fluid flowing in the opposite direction (from the outlet section to the inlet section) is extremely high, and this harmful process will be blocked by the flow channel. The greater the pressure difference between liquid A and liquid B, the better the effect of the flow channel in preventing backflow. From this point of view, the Tesla valve can balance the pressure of liquids A and B and ensure that liquid B enters the hole of liquid A for mixing.

[0038] [3] When the A liquid and AB liquids become blocked due to excessive solidification in the A liquid hole, the B liquid hose can be replaced with high-pressure water. The high-pressure water flows through the flow channel in the forward direction to clear the blockage. Then, the B liquid can be replaced and the two-liquid grouting can continue.

[0039] [4] When the pressure difference between A and B is too large, causing some of the A liquid to flow back into the flow channel and solidify to form a blockage, the B liquid pipe can be replaced with high-pressure water. At the same time, the plug at the second interface can be opened, and the blockage can be discharged through the second interface using high-pressure water.

[0040] [5] When the blockage in the flow channel is long and cannot be cleared in a short time and the two-liquid grouting does not meet the conditions for stopping, the B-liquid pipe can be reversed at the second interface and high-pressure water can be introduced. The blockage in the mixing hole can be flushed out first by the high-pressure water, and then the B-liquid can be replaced. The B-liquid can be injected into the A-liquid hole by the B-liquid pipe → second interface → mixing hole to maintain the effect of the two-liquid grouting.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A double-slurry injection check valve structure for a tunnel boring machine, comprising a flow channel internally connected to a liquid hole A and a liquid pipe B, characterized in that: The flow guide block is fixed to the inner side of the rear shield shell plate, and the flow channel passes through both ends of the flow guide block in the length direction; The flow channel includes an inlet section, an outlet section, a mixing hole perpendicularly connected to the outlet section, and at least four annular flow channels connected in series between the inlet section and the outlet section; The total length of the inlet section and the outlet section accounts for no more than 25% of the length of the drainage block. The inlet section has a first interface for connecting the B liquid tube at the opening on the end face of the drainage block. The outlet section has a second interface with a removable plug inside at the opening on the end face of the drainage block. The first interface and the second interface have the same specifications. The mixing hole penetrates the outer side of the guide block and communicates with the A liquid hole. The mixing hole is located near the connection between the outlet section and the annular flow channel. Each of the annular flow channels includes an inclined section and a semi-annular section bypassing both ends of the inclined section. The inclined sections of adjacent annular flow channels have opposite inclination directions. The semi-annular sections of adjacent annular flow channels are located on both sides of the axis of the inlet section. The semi-annular sections are teardrop-shaped, so that the flow channels constitute a Tesla flow channel with a backflow prevention function.

2. The shield machine double-slurry injection anti-reverse structure according to claim 1, characterized in that: The outer side of the diversion block is provided with a positioning boss. When the diversion block is fixed to the inner side of the rear shield shell plate, the positioning boss is embedded in the positioning groove on the rear shield shell plate, and the mixing hole passes through the positioning boss.

3. The shield machine double-slurry injection anti-reverse structure according to claim 2, characterized in that: The positioning boss is waist-shaped.

4. The shield machine double-slurry injection anti-reverse structure according to claim 2, characterized in that: The outer side of the drainage block is provided with an annular groove surrounding the positioning boss, and an O-ring is provided in the annular groove.

5. The shield machine double-slurry injection anti-reverse structure according to claim 1, characterized in that: The flow channel is composed of two plates joined together, and the flow channel is symmetrically distributed along the joint surface of the two plates. After joining, the two plates are connected as one unit by watertight welding.

6. The shield machine double-slurry injection anti-reverse structure according to claim 5, characterized in that: The plate is also provided with threaded holes, and there are multiple threaded holes symmetrically distributed on both sides of the flow channel.

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