Carbon dioxide foaming device for subway shield muck improvement

Abstract

The utility model discloses a subway shield carbon dioxide foaming device for earth improvement relates to foaming technical field, including carbon dioxide supply mechanism, foaming agent solution supply mechanism, control host computer, foam generating mechanism and foam output mechanism, be provided with control panel, flow control valve and proportional pump in control host computer, foam generating mechanism includes venturi and air inlet pipe, the input of flow control valve is connected carbon dioxide supply mechanism, and the air inlet end of air inlet pipe is connected to the output, the input of proportional pump is connected foaming agent solution supply mechanism, and the inlet end of venturi is connected to the output, the outlet end of venturi is connected foam output mechanism, the utility model discloses under the integration of flow control valve and proportional pump in control host computer, and by control panel carries out the cooperative control, can effectively improve the adjustment convenience of device, is favorable to realize the quick response and linkage of gas liquid two roads, guarantees the dry and wet even of the foam generated, and quality is stable.

Description

Technical Field

[0001] This utility model relates to the field of foaming technology, specifically to a carbon dioxide foaming device for improving the slag and soil of subway tunnel boring machines. Background Technology

[0002] In subway tunnel construction, the shield tunneling method is widely used due to its advantages such as high efficiency and safety. During the tunneling process, the shield machine continuously generates a large amount of excavated soil. The physical properties of this excavated soil (such as viscosity, water content, and particle distribution) directly affect the tunneling efficiency of the shield machine, cutterhead wear, and the smoothness of the soil removal system. If the excavated soil properties are poor, "mud cake" phenomenon is likely to occur, leading to increased cutterhead torque, decreased tunneling speed, and even engineering risks such as surface subsidence.

[0003] To address the aforementioned issues, spoil remediation technology has become a crucial aspect of tunnel boring machine (TBM) construction. Currently, the most prevalent method involves injecting foam into the tunnel face and soil chamber to improve the spoil. Foam injection serves to lubricate, provide support, reduce permeability, and alter the fluidity of the spoil, thereby making it more uniform, stable, and easier to remove.

[0004] In indoor experiments on slag improvement, foam is an important raw material, and the core equipment for generating foam is a complete foaming device.

[0005] Currently, the foaming devices used in indoor experiments for soil improvement typically consist of independently connected compressed air supply units, foaming agent solution supply units, and gas-liquid mixing foamers via simple piping. However, when attempting to replace the foaming medium with carbon dioxide, this traditional device structure reveals systemic problems: the valves controlling gas flow and the pumps controlling liquid flow are two completely separate mechanisms, making adjustment inconvenient and unable to achieve rapid response and linkage between the gas and liquid paths. This results in uneven foam consistency and large quality fluctuations. Utility Model Content

[0006] The purpose of this utility model is to overcome the shortcomings of the prior art. This utility model provides a carbon dioxide foaming device for improving the slag in subway shield tunneling. By integrating the carbon dioxide flow control valve and the proportioning pump of the foaming agent solution under the control host and coordinating them with the control panel, the device can effectively improve the adjustment convenience, facilitate the rapid response and linkage of the gas and liquid paths, and ensure that the generated foam is uniform in dryness and wetness and has stable quality.

[0007] This utility model provides a carbon dioxide foaming device for improving the slag in subway tunnel boring machines, including a carbon dioxide supply mechanism based on pipeline connection, a foaming agent solution supply mechanism, a control host, a foam generating mechanism, and a foam output mechanism. The control host is equipped with a control panel, a flow control valve and a proportional pump, and the control panel is electrically connected to the flow control valve and the proportional pump respectively. The foam generating mechanism includes a venturi tube and an air inlet pipe fixedly mounted on the venturi tube. The air inlet end of the air inlet pipe protrudes outside the venturi tube, and the air outlet end of the air inlet pipe extends into the venturi tube. The input end of the flow control valve is connected to the carbon dioxide supply mechanism, and the output end of the flow control valve is connected to the inlet end of the air inlet pipe; the input end of the proportional pump is connected to the foaming agent solution supply mechanism, and the output end of the proportional pump is connected to the inlet end of the venturi tube; the outlet end of the venturi tube is connected to the foam output mechanism.

[0008] Specifically, the carbon dioxide supply mechanism includes a carbon dioxide cylinder, a main pressure reducing valve, and a gas flow meter. The input end of the main pressure reducing valve is connected to the carbon dioxide cylinder, the output end of the main pressure reducing valve is connected to the gas flow meter, and the output end of the gas flow meter is connected to the input end of the flow control valve.

[0009] Specifically, the carbon dioxide supply mechanism includes a first carbon dioxide cylinder, a second carbon dioxide cylinder, a first main pressure reducing valve, a second main pressure reducing valve, a first gas flow meter, a second gas flow meter, and a three-way valve. The output end of the first carbon dioxide cylinder is sequentially connected to the first main pressure reducing valve and the first gas flow meter, and the output end of the second carbon dioxide cylinder is sequentially connected to the second main pressure reducing valve and the second gas flow meter. The three-way valve has a first inlet, a second inlet, and a total outlet. The output end of the first gas flow meter is connected to the first inlet, the output end of the second gas flow meter is connected to the second inlet, and the total outlet is connected to the input end of the flow control valve.

[0010] Specifically, the foaming agent solution supply mechanism includes a foaming agent storage tank, a stirring paddle rotatably disposed inside the foaming agent storage tank, a drain pipe fixedly disposed at the bottom of the foaming agent storage tank, and a cover plate fixedly disposed at the top of the foaming agent storage tank. A stirring motor is fixedly disposed on the cover plate, and the output end of the stirring motor is connected to the stirring paddle. The cover plate is provided with a solid feeding port and a water injection port, and the drain pipe is provided with a first switching valve.

[0011] Specifically, a first hopper is connected to the solid feeding port, and a filter screen is provided in the first hopper.

[0012] Specifically, a second hopper is fixedly installed on the water inlet.

[0013] Specifically, the Venturi tube includes an inlet section, a constriction section, a throat, a diffuser section, and an outlet section connected in sequence. The air inlet pipe is fixedly installed on the constriction section, the outlet end of the air inlet pipe points to the throat, and the center of the outlet end of the air inlet pipe is located on the axis of the Venturi tube. The inlet section is connected to the output end of the proportional pump, and the outlet section is connected to the foam output mechanism.

[0014] Specifically, the constriction section has a support frame formed inside, and the support frame and the air intake pipe are connected as one unit.

[0015] Specifically, the foam output mechanism includes a gripping part and a spray pipe mounted on the gripping part. The gripping part and the spray pipe are connected. One end of the gripping part away from the spray pipe is connected to the outlet end of the venturi tube. A second switching valve is installed on the gripping part.

[0016] Specifically, the end of the injection tube furthest from the grip is a conical nozzle; or The end of the spray tube away from the grip is a closed hemispherical structure, and the spray tube is provided with multiple spray holes in a circumferential array.

[0017] Compared with the prior art, the beneficial effects of this utility model are: In this utility model of a carbon dioxide foaming device for improving the slag in subway tunnel boring machines, the control of the gas (carbon dioxide) pathway (flow control valve) and the control of the liquid (foaming agent solution) pathway (proportional pump) are integrated into a unified control host and coordinated by the control panel. This changes the loose structure of the independent gas and liquid pathways in traditional devices, effectively improving the ease of adjustment of the device, facilitating rapid response and linkage of the gas and liquid pathways, and achieving centralized and precise control of the gas and liquid flow rates. This ensures that the carbon dioxide and foaming agent solution maintain a preset and stable mixing ratio, guaranteeing that the generated foam is uniform in dryness and wetness and has stable quality. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the carbon dioxide foaming device for improving the slag in subway tunnel boring machines, as described in this utility model embodiment. Figure 2This is a schematic diagram of the frame of the carbon dioxide foaming device for improving the slag in subway tunnel boring machines, as described in this utility model embodiment. Figure 3 This is a front view of the control host in an embodiment of the present invention. Figure 4 This is a first structural schematic diagram of the carbon dioxide supply mechanism in an embodiment of this utility model; Figure 5 This is a schematic diagram of the second structure of the carbon dioxide supply mechanism in an embodiment of this utility model; Figure 6 This is an exploded structural diagram of the foaming agent solution supply mechanism in an embodiment of this utility model; Figure 7 This is a three-dimensional structural schematic diagram of the foaming agent solution supply mechanism in an embodiment of this utility model; Figure 8 This is a schematic diagram of the bottom structure of the first hopper in an embodiment of this utility model; Figure 9 This is a cross-sectional structural schematic diagram of the foam generating mechanism in an embodiment of this utility model; Figure 10 This is a schematic diagram of the first structure of the foam output mechanism in an embodiment of this utility model; Figure 11 This is a schematic diagram of the second structure of the foam output mechanism in an embodiment of this utility model.

[0020] In the attached diagram, 100 is a carbon dioxide supply mechanism; 101 is a carbon dioxide cylinder; 102 is a main pressure reducing valve; 103 is a gas flow meter; 111 is a first carbon dioxide cylinder; 112 is a first main pressure reducing valve; 113 is a first gas flow meter; 121 is a second carbon dioxide cylinder; 122 is a second main pressure reducing valve; 123 is a second gas flow meter; 130 is a three-way valve; 200 is a foaming agent solution supply mechanism; 210 is a foaming agent storage tank; 220 is a stirring paddle; 230 is a drain pipe; 231 is a first switching valve; 240 is a cover plate; 241 is a solid feed port; 242 is a water inlet; and 250 is a stirring motor. 260. First hopper; 261. Filter screen; 270. Second hopper; 300. Control unit; 310. Flow control valve; 320. Proportional pump; 331. Main power switch; 332. Airflow knob; 333. Liquid flow knob; 334. Indicator light; 335. Display screen; 400. Foam generating mechanism; 410. Venturi tube; 411. Inlet section; 412. Contraction section; 413. Throat; 414. Diffusion section; 415. Outlet section; 420. Air inlet pipe; 430. Support frame; 500. Foam output mechanism; 510. Grip part; 511. Second switching valve; 520. Injection pipe. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0022] This invention provides a carbon dioxide foaming device for improving the slag and soil from subway tunnel boring machines. Figure 1 This diagram illustrates the structure of a carbon dioxide foaming device for improving the slag from subway tunnel boring machines, as shown in an embodiment of this invention. Figure 2 This illustration shows a schematic diagram of the frame of a carbon dioxide foaming device for improving the slag in subway tunnel boring machines according to an embodiment of the present invention. The carbon dioxide foaming device includes a carbon dioxide supply mechanism 100, a foaming agent solution supply mechanism 200, a control host 300, a foam generating mechanism 400, and a foam output mechanism 500, all connected by pipelines. The control host 300 includes a control panel, a flow control valve 310, and a proportional pump 320, with the control panel electrically connected to both the flow control valve 310 and the proportional pump 320. The foam generating mechanism 400 includes a Venturi tube 410 and a foam output mechanism 500 fixedly mounted on the Venturi tube. An air inlet pipe 420 is provided on the Venturi tube 410, with the air inlet end of the air inlet pipe 420 protruding outside the Venturi tube 410 and the air outlet end of the air inlet pipe 420 extending into the Venturi tube 410; the input end of the flow control valve 310 is connected to the carbon dioxide supply mechanism 100, and the output end of the flow control valve 310 is connected to the air inlet end of the air inlet pipe 420; the input end of the proportional pump 320 is connected to the foaming agent solution supply mechanism 200, and the output end of the proportional pump 320 is connected to the inlet end of the Venturi tube 410; the outlet end of the Venturi tube 410 is connected to the foam output mechanism 500.

[0023] In this utility model of a carbon dioxide foaming device for improving the slag in subway tunnel boring machines, the control of the gas (carbon dioxide) pathway (flow control valve 310) and the control of the liquid (foaming agent solution) pathway (proportional pump 320) are integrated into a unified control host 300, and coordinated by the control panel. This changes the loose structure of the independent gas and liquid pathways in traditional devices, effectively improving the ease of adjustment of the device, facilitating rapid response and linkage of the gas and liquid pathways, and achieving centralized and precise control of the gas and liquid flow rates. This ensures that the carbon dioxide and foaming agent solution maintain a preset and stable mixing ratio, guaranteeing that the generated foam is uniform in dryness and wetness and has stable quality.

[0024] Figure 3The diagram shows the front view of the control host in an embodiment of the present invention. The control panel is equipped with a main power switch 331, an airflow knob 332, a liquid flow knob 333, an indicator light 334, and a display screen 335, which can precisely control the operation of the flow control valve 310 and the proportional pump 320.

[0025] Figure 4 A first structural schematic diagram of the carbon dioxide supply mechanism in an embodiment of this utility model is shown. The carbon dioxide supply mechanism 100 includes a carbon dioxide cylinder 101, a main pressure reducing valve 102, and a gas flow meter 103. The input end of the main pressure reducing valve 102 is connected to the carbon dioxide cylinder 101, and the output end of the main pressure reducing valve 102 is connected to the gas flow meter 103. The output end of the gas flow meter 103 is connected to the input end of the flow control valve 310. The carbon dioxide cylinder 101 is a high-pressure gas storage source, with the internal gas at a very high pressure (typically 5~7 MPa). The main pressure reducing valve 102 can reduce the unstable high pressure at the cylinder outlet to a stable, lower, and manageable output pressure (e.g., 0.5~1 MPa) in one go. This helps protect downstream low-pressure equipment (such as the flow meter and flow control valve 310) from damage caused by high-pressure impact and provides a stable gas source pressure for the entire system. The gas flow meter 103 is a monitoring device used to display the instantaneous flow rate of carbon dioxide gas flowing through the pipeline in real time, providing visualized flow data for operators or control systems for observation and verification.

[0026] Figure 5 A second structural schematic diagram of the carbon dioxide supply mechanism in an embodiment of the present invention is shown. The carbon dioxide supply mechanism 100 includes a first carbon dioxide cylinder 111, a second carbon dioxide cylinder 121, a first main pressure reducing valve 112, a second main pressure reducing valve 122, a first gas flow meter 113, a second gas flow meter 123, and a three-way valve 130. The output end of the first carbon dioxide cylinder 111 is sequentially connected to the first main pressure reducing valve 112 and the first gas flow meter 113. The output end of the second carbon dioxide cylinder 121 is sequentially connected to the second main pressure reducing valve 122 and the second gas flow meter 123. The three-way valve 130 has a first inlet, a second inlet, and a total outlet. The output end of the first gas flow meter 113 is connected to the first inlet, the output end of the second gas flow meter 123 is connected to the second inlet, and the total outlet is connected to the input end of the flow control valve 310.

[0027] The carbon dioxide supply mechanism 100 employs a dual-cylinder redundancy design, with a three-way valve 130 for switching. Its core function is to ensure uninterrupted and highly reliable gas supply. When the first gas cylinder in use is depleted or its pipeline fails, the system can quickly switch to the second backup gas cylinder to continue supplying gas, thereby ensuring a continuous and stable flow of carbon dioxide to downstream equipment. This effectively avoids gas supply interruptions caused by single cylinder replacement or single-path failure, guaranteeing the continuous and stable operation of related processes or equipment.

[0028] Figure 6 An exploded view of the foaming agent solution supply mechanism in an embodiment of this utility model is shown. Figure 7 A three-dimensional structural schematic diagram of the foaming agent solution supply mechanism in an embodiment of the present invention is shown. The foaming agent solution supply mechanism 200 includes a foaming agent storage tank 210, a stirring paddle 220 rotatably disposed inside the foaming agent storage tank 210, a drain pipe 230 fixedly disposed at the bottom of the foaming agent storage tank 210, and a cover plate 240 fixedly disposed at the top of the foaming agent storage tank 210. A stirring motor 250 is fixedly disposed on the cover plate 240, and the output end of the stirring motor 250 is connected to the stirring paddle 220. A solid feeding port 241 and a water injection port 242 are provided on the cover plate 240, and a first switching valve 231 is provided on the drain pipe 230.

[0029] The foaming agent solution supply mechanism 200, through its integrated design, achieves the preparation, storage, and uniform supply of the foaming agent solution. Operators can conveniently prepare the solution via the top solid feed port 241 and water inlet 242. The stirring motor 250 drives the stirring paddle 220 to continuously operate, ensuring uniform solution concentration within the storage tank and preventing sedimentation. Finally, through the bottom drain pipe 230 and the first switching valve 231, a homogeneous foaming agent solution can be stably and controllably supplied to the next stage as needed.

[0030] For details, please refer to Figure 6 and Figure 7 The solid feeding port 241 is fitted with a first hopper 260; Figure 8 The diagram shows the bottom structure of the first hopper in this embodiment of the invention. A filter screen 261 is installed in the first hopper 260. The filter screen 261 can effectively intercept and separate any clumps or impurities that may exist in the solid foaming agent, preventing them from entering the storage tank, thereby avoiding blockage of subsequent pipes and valves, and ensuring the uniformity of solution purity. Simultaneously, the hopper structure enlarges the feeding interface, making the addition of powdered or granular foaming agent more convenient and centralized, reducing dust and material spillage.

[0031] For further details, please refer to Figure 6 and Figure 7A second hopper 270 is fixedly installed on the water inlet 242. By adding the second hopper 270 to the water inlet 242, it plays a guiding and expanding role, making the operation of injecting water into the foaming agent storage tank 210 more convenient and efficient, and effectively preventing water splashing. It is especially practical when manual water or other liquid additives need to be added, ensuring the cleanliness and safety of the work area.

[0032] Figure 9 A cross-sectional structural schematic diagram of the foam generating mechanism in an embodiment of the present invention is shown. The venturi tube 410 includes an inlet section 411, a contraction section 412, a throat 413, a diffuser section 414, and an outlet section 415 connected in sequence. The air inlet pipe 420 is fixedly disposed on the contraction section 412, and the outlet end of the air inlet pipe 420 points to the throat 413. The center of the outlet end of the air inlet pipe 420 is located on the axis of the venturi tube 410. The inlet section 411 is connected to the output end of the proportional pump 320, and the outlet section 415 is connected to the foam output mechanism 500.

[0033] In this system, the core function of the Venturi tube 410 is to provide an efficient mixing and energy exchange site for the actively supplied carbon dioxide gas and the pumped foaming agent solution. When the proportional pump 320 pressurizes the foaming agent solution into the contraction section 412 of the Venturi tube 410 and accelerates it, the low-pressure environment formed at the throat 413 is not used to "inhale" gas, but rather to greatly reduce the back pressure of the injected gas. At this time, the carbon dioxide gas actively supplied from the inlet pipe 420 and directed towards the throat 413 can meet the high-speed liquid flow with minimal resistance, and be violently sheared and torn into fine bubbles. Subsequently, the gas-liquid mixture is decelerated and pressurized in the diffusion section 414, completing the final refinement and stabilization of the foam, thereby generating high-quality foam.

[0034] For details, please refer to Figure 9 The constriction section 412 has a support frame 430 internally formed, which is integrated with the air inlet pipe 420. The support frame 430 provides robust support and precise positioning for the actively intake air pipe 420. It not only effectively resists the vibration and stress caused by the gas backlash and prevents fatigue fracture of the air inlet pipe 420, but more importantly, it ensures that the center of the air outlet end of the air inlet pipe 420 is always firmly on the axis of the venturi tube 410, thereby ensuring that the gas is injected into the high-speed liquid flow uniformly and symmetrically, which is the key to generating stable and homogeneous foam.

[0035] Figure 10A first structural schematic diagram of the foam output mechanism in an embodiment of the present invention is shown. The foam output mechanism 500 includes a grip portion 510 and a spray pipe 520 mounted on the grip portion 510. The grip portion 510 and the spray pipe 520 are connected. One end of the grip portion 510 away from the spray pipe 520 is connected to the outlet end of the venturi tube 410. A second switching valve 511 is mounted on the grip portion 510. By integrating the grip portion 510, the second switching valve 511, and the spray pipe 520, the foam output mechanism 500 provides the operator with a terminal tool that integrates on / off control, direction guidance, and handheld operation. The operator can hold the grip portion 510 to directly control the spray direction of the foam. By operating the second switching valve 511, the foam delivery can be turned on or off instantly and conveniently, thereby achieving precise manual control of the foam application process.

[0036] Optional, please refer to Figure 10 The end of the spray pipe 520 away from the gripping part 510 is a conical nozzle. The conical nozzle, through its converging geometry, can concentrate and accelerate the flowing foam. It can reduce the flow cross section of the foam, significantly improve the outlet velocity and spray force of the foam, thereby forming a concentrated, dense foam jet with stronger penetrating power. This not only effectively reduces the dispersion and splashing of foam, but also allows the foam to cover the slag more accurately and efficiently.

[0037] Optional, Figure 11 The diagram shows a second structural schematic of the foam output mechanism in this embodiment of the invention. The end of the spray pipe 520 furthest from the gripping part 510 is a closed hemispherical structure, and multiple spray holes are arranged in a circumferential array on the spray pipe 520. By changing the end of the spray pipe 520 to a closed hemispherical structure and circumferentially arraying multiple spray holes, a point-to-multipoint, all-round, three-dimensional, gentle, and uniform foam spraying is achieved. It completely changes the foam outflow method, from a concentrated jet to a multi-directional diffusion flow, thereby instantly covering a wider area and achieving rapid and uniform foam coating or filling, while effectively avoiding splashing caused by a single high-speed jet. Moreover, the spray pipe 520 can be directly inserted into the slag, and with the help of the circumferential spray holes, all-round, three-dimensional, and efficient foam release and mixing can be achieved from within the slag body. This achieves rapid and uniform mixing of foam and slag in three-dimensional space, which can greatly improve the fluidity of the slag ("lubricating" the soil), thereby significantly improving the excavation efficiency.

[0038] The operation process of the carbon dioxide foaming device for improving the slag in subway tunnel boring machines of this utility model is as follows: First, add solid foaming agent and water (or directly add foaming agent solution) to the foaming agent storage tank 210, and turn on the stirring motor 250 to drive the stirring paddle 220 to rotate, so as to ensure that the solution concentration in the storage tank is uniform and to avoid sedimentation. Next, the first switch valve 231 at the bottom of the foaming agent storage tank 210 is opened, and the foaming agent solution is delivered to the proportional pump 320 in the control host 300 by gravity. Next, open the carbon dioxide cylinder 101, adjust the main pressure reducing valve 102 and the gas flow meter 103, and supply carbon dioxide to the flow control valve 310 in the control host 300. Then, turn on the main power switch 331 of the control unit 300, and precisely control the operation of the flow control valve 310 and the proportional pump 320 by adjusting the airflow flow knob 332 and the liquid flow knob 333. When the proportional pump 320 pressurizes the foaming agent solution into the contraction section 412 of the venturi tube 410 and accelerates it, the low-pressure environment formed at the throat 413 is not used to "inhale" gas, but greatly reduces the back pressure of the gas injection; at this time, the carbon dioxide gas actively supplied from the air inlet pipe 420 and directed towards the throat 413 can meet the high-speed liquid flow with minimal resistance, and be violently sheared and torn into fine bubbles; subsequently, the gas-liquid mixture decelerates and pressurizes in the diffusion section 414, completing the final refinement and stabilization of the foam, thereby generating high-quality foam; Finally, grasp the grip part 510, open the second switch valve 511, and release the foam from the spray pipe 520.

[0039] This utility model discloses a carbon dioxide foaming device for improving the slag in subway tunnel boring machines. It integrates the control of the gas (carbon dioxide) flow path (flow control valve 310) and the liquid (foaming agent solution) flow path (proportional pump 320) into a unified control host 300, which is then coordinated and controlled by the control panel. This changes the traditional loose structure of separate gas and liquid paths, effectively improving the device's adjustment convenience. It facilitates rapid response and linkage between the gas and liquid paths, enabling centralized and precise control of gas and liquid flow rates. This ensures that the carbon dioxide and foaming agent solution maintain a preset, stable mixing ratio, guaranteeing uniform wetness and stable quality of the generated foam.

[0040] Furthermore, the carbon dioxide supply mechanism 100 can adopt a dual-cylinder redundancy design, which, in conjunction with the three-way valve 130, allows for switching, ensuring uninterrupted and highly reliable gas supply. When the first gas cylinder in use is depleted or its pipeline fails, the system can quickly switch to the second backup gas cylinder to continue supplying gas, thereby ensuring a continuous and stable flow of carbon dioxide to downstream equipment. This effectively avoids gas supply interruptions caused by single cylinder replacement or single-path failure, guaranteeing the continuous and stable operation of related processes or equipment.

[0041] Furthermore, the gripping part 510 of the foam output mechanism 500 can be equipped with different injection pipes 520. By using an injection pipe 520 with a conical nozzle, the flowing foam can be bundled and accelerated through its converging geometry, thereby reducing the flow cross-section of the foam and significantly increasing the outlet speed and injection force of the foam, thus forming a concentrated, dense foam jet with stronger penetrating power. This not only effectively reduces foam dispersion and splashing, but also allows the foam to cover the slag more accurately and efficiently.

[0042] The end of the spray pipe 520 can also be modified into a closed hemispherical structure with multiple nozzles arranged in a circumferential array. This achieves one-to-many, all-round, three-dimensional, gentle, and uniform foam spraying. It completely changes the foam outflow method, changing from a concentrated jet to a multi-directional diffusion flow, thereby instantly covering a wider area and achieving rapid and uniform foam coating or filling, while effectively avoiding splashing caused by a single high-speed jet. Moreover, the spray pipe 520 can be directly inserted into the slag, using the circumferential nozzles to release and mix foam from within the slag mass in an all-round, three-dimensional, and efficient manner. This achieves rapid and uniform mixing of foam and slag in three-dimensional space, which can greatly improve the fluidity of the slag ("lubricating" the soil), thereby significantly improving the excavation efficiency.

[0043] The above provides a detailed description of a carbon dioxide foaming device for improving the slag in subway tunnel boring machines, as provided in the embodiments of this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A carbon dioxide foaming device for improving the slag from subway tunnel boring machines, characterized in that, It includes a carbon dioxide supply mechanism based on pipeline connection, a foaming agent solution supply mechanism, a control host, a foam generating mechanism, and a foam output mechanism; The control host is equipped with a control panel, a flow control valve and a proportional pump, and the control panel is electrically connected to the flow control valve and the proportional pump respectively. The foam generating mechanism includes a venturi tube and an air inlet pipe fixedly mounted on the venturi tube. The air inlet end of the air inlet pipe protrudes outside the venturi tube, and the air outlet end of the air inlet pipe extends into the venturi tube. The input end of the flow control valve is connected to the carbon dioxide supply mechanism, and the output end of the flow control valve is connected to the inlet end of the air inlet pipe; the input end of the proportional pump is connected to the foaming agent solution supply mechanism, and the output end of the proportional pump is connected to the inlet end of the venturi tube; the outlet end of the venturi tube is connected to the foam output mechanism.

2. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 1, characterized in that, The carbon dioxide supply mechanism includes a carbon dioxide cylinder, a main pressure reducing valve, and a gas flow meter. The input end of the main pressure reducing valve is connected to the carbon dioxide cylinder, the output end of the main pressure reducing valve is connected to the gas flow meter, and the output end of the gas flow meter is connected to the input end of the flow control valve.

3. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 1, characterized in that, The carbon dioxide supply mechanism includes a first carbon dioxide cylinder, a second carbon dioxide cylinder, a first main pressure reducing valve, a second main pressure reducing valve, a first gas flow meter, a second gas flow meter, and a three-way valve. The output end of the first carbon dioxide cylinder is sequentially connected to the first main pressure reducing valve and the first gas flow meter, and the output end of the second carbon dioxide cylinder is sequentially connected to the second main pressure reducing valve and the second gas flow meter. The three-way valve has a first inlet, a second inlet, and a total outlet. The output end of the first gas flow meter is connected to the first inlet, the output end of the second gas flow meter is connected to the second inlet, and the total outlet is connected to the input end of the flow control valve.

4. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 1, characterized in that, The foaming agent solution supply mechanism includes a foaming agent storage tank, a stirring paddle rotatably disposed inside the foaming agent storage tank, a drain pipe fixedly disposed at the bottom of the foaming agent storage tank, and a cover plate fixedly disposed at the top of the foaming agent storage tank. A stirring motor is fixedly disposed on the cover plate, and the output end of the stirring motor is connected to the stirring paddle. The cover plate is provided with a solid feeding port and a water injection port, and the drain pipe is provided with a first switching valve.

5. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 4, characterized in that, A first hopper is connected to the solid feed port, and a filter screen is installed in the first hopper.

6. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 4, characterized in that, A second hopper is fixedly installed on the water inlet.

7. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 1, characterized in that, The Venturi tube includes an inlet section, a constriction section, a throat, a diffuser section, and an outlet section connected in sequence. The air inlet pipe is fixedly installed on the constriction section, and the outlet end of the air inlet pipe points to the throat. The center of the outlet end of the air inlet pipe is located on the axis of the Venturi tube. The inlet section is connected to the output end of the proportional pump, and the outlet section is connected to the foam output mechanism.

8. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 7, characterized in that, The constriction section has a support frame formed inside, and the support frame and the air intake pipe are connected as one piece.

9. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 1, characterized in that, The foam output mechanism includes a gripping part and a spray pipe mounted on the gripping part. The gripping part and the spray pipe are connected. The end of the gripping part away from the spray pipe is connected to the outlet end of the venturi tube. A second switching valve is installed on the gripping part.

10. The carbon dioxide foaming device for improving tunnel blast soil as described in claim 9, characterized in that, The end of the injection tube away from the grip is a conical nozzle; or The end of the spray tube away from the grip is a closed hemispherical structure, and the spray tube is provided with multiple spray holes in a circumferential array.

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