A powder spraying pile background of air lock type pulse feeding

Abstract

The utility model discloses a kind of powder spray pile background of airlock type pulse feeding, to solve the precision difference of existing mechanical discharging mode, and the cost and stability contradiction existing in pressure regulation discharging technology. The utility model core lies in using the airlock type quantitative discharging unit of " filling valve-quantitative cavity-jet valve " composition, its filling valve and jet valve time-sharing opening and closing, with high-pressure conveying pipeline physical isolation to material tank, with " batch, volumetric " brand-new principle fundamentally guarantees quantitative accuracy. Meanwhile, control unit is intermittently opened and closed to the switch valve on single gas source main pipeline, and intelligently manages gas source distribution with pulse gas supply strategy, solves the power contradiction of material tank pressure stabilization and main pipeline conveying. Through the utility model, realize the stable work of high-precision quantitative discharging unit driven by the economic configuration of single gas source, and greatly enhance the conveying capacity and construction reliability under complex working conditions such as long distance, great depth.

Description

Technical Field

[0001] This utility model relates to the field of underground engineering construction machinery and equipment technology, specifically to a powder jet grouting pile backing system with air-lock pulse feeding. Background Technology

[0002] As an efficient in-situ reinforcement method for soft soil foundations, the quality of powder jet grouting piles is closely related to the precise and uniform distribution of the curing agent, which places stringent quantitative control requirements on the powder supply system in the construction process.

[0003] However, existing powder jet grouting construction systems generally fall short in achieving precise quantitative material feeding. Traditional equipment often uses mechanical devices such as rotary feeders to control material feeding. The actual output of these devices is highly susceptible to dynamic influences from various factors, including the physical properties of the powder, the material level in the silo, fluctuations in back pressure at the outlet, and the wear and tear of mechanical components, making it difficult to achieve highly repeatable quantitative feeding. More seriously, when the pressure in the conveying pipeline is high, the high-pressure airflow can backflow into the upper conveying tank through the gaps between the rotating blades, creating an "air resistance" phenomenon that severely hinders the smooth descent of powder. This problem is particularly prominent during long pile construction, often leading to difficulties or even interruptions in deep material feeding, resulting in serious quality defects such as insufficient pile length or uneven pile strength.

[0004] To fundamentally address the shortcomings of traditional mechanical feeding methods, the applicant, in a series of patent applications filed on the same filing date, proposed a new generation of quantitative feeding technology based on real-time sensor feedback for dynamic control. This technical approach manifests in two main methods: one relies solely on dynamically adjusting the tank pressure to control the feeding rate; the other, more sophisticated approach, simultaneously adjusting the tank pressure and coordinating with the rotational speed of the built-in screw feeding mechanism to precisely regulate the feeding quantity. Both methods monitor the real-time feeding quantity and adjust control parameters accordingly (such as tank pressure and screw speed) to stabilize the feeding rate at the target value. This represents a significant advancement compared to traditional mechanical devices and meets the precision and reliability requirements of conventional construction.

[0005] However, after in-depth research, the applicant discovered that these pressure-controlled technologies still face new challenges in application: if an economical single air supply unit configuration is adopted, the strong air consumption during conveying will inevitably impact and lower the overall air pressure, thus severely interfering with the stable control conditions necessary for accurate material feeding, resulting in huge fluctuations in the material flow rate. To fundamentally solve the air source interference problem, these solutions can employ two independent air supply units. Specifically, one air supply unit is dedicated to providing a constant, interference-free pressurized air source for the conveying tank to ensure stable pressure control; the other independent air supply unit provides strong power to the pneumatic conveying pipeline. Although this dual-air source configuration can ensure relatively stable control conditions, due to the extremely complex flow characteristics of powder under pneumatic action, relying solely on dynamically adjusting parameters to "catch up" and "correct" the flow rate in real time still has an upper limit to control accuracy, and the real-time fluctuation of the conveying volume remains large. Furthermore, the dual-air source scheme also significantly increases the overall equipment cost.

[0006] Therefore, the industry urgently needs a new quantitative feeding technology solution that is superior in working principle. It must be able to fundamentally get rid of the extreme dependence on the pressure stability of the conveying tank, so as to achieve high-precision and stable feeding with an economical single air source configuration. Utility Model Content

[0007] The technical problem this invention aims to solve is to overcome the fundamental defects in the quantitative feeding stage of existing powder-jet mixing pile construction back-end systems. Specifically, these defects include: firstly, the poor accuracy and "air resistance" backflow problems caused by the structure of traditional mechanical feeding methods (such as rotary feeders); secondly, the pressure-controlled feeding technology, as an improvement, suffers from huge flow fluctuations under an economical single-air-source configuration due to its "catch-up" control principle, while even under a high-cost dual-air-source configuration, its control accuracy and stability still have upper limits, failing to perfectly solve the problem.

[0008] To address the aforementioned problems, this utility model provides a pneumatically locked pulse feeding system for powder jet grouting and its construction method. The main objective of this utility model is to propose an innovative system design and control strategy with superior working principles. Its core lies in: First, employing a pneumatically locked quantitative feeding unit based on a "filling valve - precisely sized quantitative chamber - rapidly opening and closing injection valve." Because the filling valve and injection valve open and close separately and are never interconnected, the upstream conveying tank and downstream high-pressure conveying pipeline are physically isolated. This enables high-precision quantitative feeding based on a novel "batch-based, volumetric" principle, fundamentally eliminating extreme dependence on the pressure stability of the conveying tank. Second, addressing the contradiction in the distribution of a single air supply source, an air supply pipe switch valve is installed on the main pipeline, and its intermittent opening and closing is controlled by a control unit. This effectively manages the total air consumption while ensuring stable pressurization of the main conveying tank and providing sufficient and effective airflow power to the main conveying pipeline. The present invention aims to provide a back-end technical solution for large-diameter, deep powder jet grouting pile foundation projects, which features precise material feeding, reliable conveying, intelligent control, and high cost-effectiveness, through the above-mentioned scheme.

[0009] To achieve the objectives of this utility model, the following technical solution is adopted:

[0010] A powder jet grouting backing system with airlock pulse feeding includes an air supply unit, a material supply unit, a quantitative feeding unit, a pneumatic conveying unit, and a control unit for coordinating the operation of each unit. The material supply unit includes a material tank body and a guide pipe connected to the outlet of the material tank body. The material tank body is connected to the air supply unit through a material tank inlet pipe to achieve pressurized air supply. The pneumatic conveying unit includes at least one air supply pipe and a gas-solid mixing chamber. The inlet end of each air supply pipe is connected to the air supply unit to achieve air supply, and the outlet end of the air supply pipe is connected to the outlet end of the quantitative feeding unit to the gas-solid mixing chamber. The quantitative feeding unit includes a filling valve, a metering chamber, and an injection valve connected in sequence. The filling valve is connected to the outlet of the guide pipe, and the injection valve is connected to the inlet of the gas-solid mixing chamber. The control unit is configured to coordinate the opening and closing actions of the filling valve and the injection valve to achieve pulsed quantitative feeding. The air supply unit simultaneously supplies air to both the pneumatic conveying unit and the feeding unit. The control unit enables pulsed air supply, which ensures stable pressurization of the conveying tank and enhances the conveying power through pulsed airflow. This avoids the problem of "mutual restraint between conveying power and tank pressure guarantee" under traditional single air source conditions. The control unit coordinates the opening and closing actions to achieve pulsed quantitative feeding. Compared with traditional rotary feeders, this avoids interference from factors such as powder physical properties and back pressure fluctuations on feeding accuracy.

[0011] Preferably, the air supply unit includes an air supply module consisting of an air compressor, an air storage tank, and a refrigerated dryer. The output air path of the air supply module is configured to simultaneously provide a conveying air source to the pneumatic conveying unit and a pressurized air source to the conveying tank body of the feeding unit. The air inlet end of the conveying tank's air inlet pipe and the air inlet end of the conveying pipe converge and connect to the output air path of the air supply module. An air inlet valve is provided on the conveying pipe, and the control unit controls the intermittent opening and closing of the air inlet valve to provide a pulsed conveying air source to the pneumatic conveying unit. By intermittently opening and closing the air inlet valve through the control unit, the total air consumption of a single air supply unit is effectively managed. This approach can maintain a stable discharge pressure in the conveying tank body while providing sufficient and effective airflow power for long-distance, deep-pile conveying, resolving the power distribution contradictions under traditional single-air-source configurations.

[0012] Preferably, the air supply unit includes two sets of air supply modules consisting of an air compressor, an air tank, and a refrigerated dryer in sequence. One set of air supply modules is used to provide a conveying air source to the pneumatic conveying unit; the air inlet end of the air conveying pipe is connected to the output air path of the air supply module; the other set is used to provide a pressurized air source to the feeding unit to maintain the feeding unit at a preset working pressure; the air inlet end of the air inlet pipe of the feeding tank is connected to the output air path of the air supply module. By establishing a separate second air supply path dedicated to providing strong pneumatic conveying power, and a separate first air supply path dedicated to maintaining the high-pressure stability of the conveying tank, combined with an airlock-type quantitative feeding unit based on a filling valve, a precisely sized metering chamber, and a fast-opening and closing injection valve, along with corresponding automated control strategies, the contradiction between the conveying tank pressure and the pneumatic conveying power in the traditional single-air-source mode is completely resolved. One air source is dedicated to maintaining the preset working pressure of the conveying tank to ensure stable powder fluidization; the other air source provides strong power for pneumatic conveying, meeting the needs of deep piles and long-distance conveying. The two do not interfere with each other, improving system stability. Through the combination of the filling valve, metering chamber, and injection valve, precise quantitative feeding is achieved using a "filling-injection" cycle. The predetermined volume of the metering chamber can accurately control the amount of powder sprayed in a single operation, avoiding fluctuations caused by material characteristics in traditional rotary feeders, ensuring a high degree of matching between the actual feeding amount and the design value, and guaranteeing the uniformity of the pile-forming curing agent dosage.

[0013] Preferably, the feeding unit further includes a support frame, a connecting flange, and a conveying tank exhaust pipe; the conveying tank body is mounted on the support frame, the bottom of the conveying tank body is connected to the guide pipe through the connecting flange, and a vibrator is provided at the bottom of the conveying tank body; the conveying tank exhaust pipe is connected to the top of the conveying tank body.

[0014] Preferably, the control unit includes a sensor group, a valve group, and a central control cabinet. The sensor group includes a weighing sensor for monitoring the weight of the powder curing agent inside the conveying tank and a conveying tank pressure gauge for monitoring the pressure inside the tank. The weight of the conveying tank body is supported by at least three weighing sensors, each of which is fixed to the support frame, and the conveying tank body is vertically pressed onto the weighing sensors. The conveying tank pressure gauge is mounted on the conveying tank body. The valve group includes a feed valve, a conveying tank pressurization valve, and a conveying tank exhaust valve. The feed valve is mounted on the conveying tank body and is used to replenish the powder curing agent. The conveying tank pressurization valve is mounted on the conveying tank air inlet pipe. The conveying tank exhaust valve is mounted on the conveying tank exhaust pipe. The central control cabinet is mounted on the support frame and is electrically connected to the vibrator, the valve group, the sensor group, and the quantitative feeding unit. By linking the feed valve, pressurizing valve, and exhaust valve through the central control cabinet, the pressure inside the tank is maintained within a preset range based on pressure gauge data, ensuring stable pressure during filling and thus guaranteeing consistent filling volume of the metering chamber.

[0015] Preferably, the central control cabinet of the control unit is configured to dynamically control the opening and closing of the pressurizing valve and the venting valve of the conveying tank based on the pressure data fed back from the pressure gauge of the conveying tank, so as to accurately maintain the pressure inside the conveying tank body within a preset working pressure range. This stable upstream pressure aims to ensure that when the filling valve opens according to a preset program to fill the metering chamber, the metering chamber can obtain a consistent amount of powder curing agent and the same initial internal pressure each time. This ensures that in each spraying cycle of the subsequent spraying valve opening according to a preset program, the amount of powder curing agent sprayed from the metering chamber is highly consistent, thereby achieving overall quantitative feeding. The central control cabinet of the control unit is further configured to, during or before filling the metering chamber through the filling valve, activate the vibrator on the outer wall of the conveying tank body in a timely manner according to preset conditions or real-time monitoring of the flow state of the powder curing agent, so as to help the powder curing agent overcome potential arching or poor flow, and ensure that it flows smoothly and quickly into the metering chamber. This stable pressure ensures that the metering chamber receives the same filling volume and initial pressure each time it is filled, thus guaranteeing a highly consistent powder dosage per cycle during injection and achieving "high-precision metering". The control unit activates the vibrator in a timely manner based on preset conditions or real-time monitoring of the powder flow state, avoiding energy waste or powder segregation caused by blind vibration, and further improving the smoothness and reliability of feeding.

[0016] Preferably, the central axis of the gas delivery pipe intersects the central axis of the gas-solid mixing chamber, and the included angle is preferably less than 60°. An angle of less than 60° between the central axis of the gas delivery pipe and the central axis of the gas-solid mixing chamber allows the conveying airflow to enter the mixing chamber at a more optimal angle, enhancing the entrainment of powder, improving gas-solid mixing efficiency, and avoiding powder accumulation or insufficient conveying power caused by unreasonable airflow angles in traditional structures.

[0017] Preferably, the gas-solid mixing chamber comprises a variable-diameter structure consisting of a contraction section at the inlet, a mixing section in the middle, and a divergence section at the outlet, connected sequentially. The contraction section has a gradually narrowing cross-section, the mixing section is a straight pipe section with a uniform cross-section, and the divergence section has a gradually expanding cross-section. The contraction section accelerates the airflow, the mixing section provides uniform mixing, and the divergence section reduces the flow velocity and stabilizes the gas-solid two-phase flow. This design effectively improves the dispersion and conveying stability of powder in the mixing chamber, making it particularly suitable for long-distance conveying requirements in large-diameter, deep pile construction.

[0018] Preferably, the longitudinal profile shape of the guide tube in the vertical plane containing the central axis of the metering cavity includes, but is not limited to, a right-angled profile, a bull-horn profile, or any other smoothly transitioned curved shape.

[0019] Preferably, the internal flow channel of the metering chamber has a variable diameter structure, which, from inlet to outlet, includes an inlet expansion section connected to the outlet of the filling valve, an intermediate constant-diameter metering section, and an outlet contraction section connected to the inlet of the injection valve. The use of right-angled, angular, or smooth curved contours reduces powder flow resistance, preventing powder blockage or uneven flow velocity caused by abrupt changes in the flow channel, ensuring smooth powder delivery from the feed tank to the metering chamber. The inlet expansion section facilitates rapid powder inflow, the intermediate constant-diameter metering section precisely defines the filling volume, and the outlet contraction section increases the powder flow velocity at the outlet. Combined with the opening and closing of the injection valve, this achieves precise metering injection, further improving the consistency of the feeding accuracy.

[0020] This invention, by employing a single air supply source and innovatively matching it with an air-lock type dual-valve quantitative feeding unit and an intelligent control strategy for intermittent air supply to the main conveying pipeline, aims to achieve one or more of the following beneficial effects compared to existing technologies:

[0021] (I) Achieving High-Precision Quantitative Feeding: The core advantage of this utility model lies in its "airlock" quantitative feeding unit. Because its filling valve and injection valve open and close separately and are never interconnected, the upstream conveying tank is physically isolated from the downstream high-pressure, fluctuating conveying pipeline. This design, combined with the "batch-based, volumetric" metering principle, fundamentally eliminates the extreme dependence of feeding accuracy on tank pressure stability, overcomes the inherent defects of traditional mechanical feeding and pressure-controlled feeding methods, and achieves highly consistent and precise quantitative supply.

[0022] (II) Efficient Management of a Single Gas Source, Combining Economy and High Performance: By intermittently opening and closing the gas pipeline valve through the control unit, the total gas consumption of a single gas supply unit is effectively managed. This measure can maintain a stable discharge pressure in the conveying tank body while providing sufficient and effective airflow power for long-distance, deep-pile conveying, thus resolving the power distribution contradictions under the traditional single gas source configuration.

[0023] (III) Enhanced Automation and Reliability: The automated and intelligent coordinated control of the quantitative feeding cycle and the gas pipeline switching valve significantly reduces reliance on manual operation and experience-based judgment, helping to reduce the risk of misoperation and improving the system's operational stability and construction standardization. Meanwhile, compared to complex mechanical devices such as rotary feeders, the "airlock" structure has fewer moving parts, making it less prone to wear and jamming, thus significantly improving the system's long-term operational stability and construction standardization.

[0024] (iv) Ensuring the construction quality of deep and large pile foundations: Through the above-mentioned high-precision and high-reliability material feeding and conveying combination, this utility model can ensure that the powder curing agent can be delivered to the bottom of the pile in a stable and precise flow rate when carrying out high-standard projects such as large-diameter and deep pile foundations, ensuring the strength continuity and material distribution uniformity of the finished pile throughout the entire depth range, and providing key technical support for improving project quality. Attached Figure Description

[0025] Figure 1 This is a front view of the overall structure of Embodiment 1 of this utility model;

[0026] Figure 2 This is a rear view of the overall structure of Embodiment 1 of this utility model;

[0027] Figure 3 This is a schematic diagram of the gas supply unit structure according to Embodiment 1 of this utility model;

[0028] Figure 4 This is a schematic diagram of the material storage unit according to Embodiment 1 of this utility model;

[0029] Figure 5 This is a pneumatic conveying circuit diagram of Embodiment 1 of this utility model;

[0030] Figure 6 This is a schematic diagram of the quantitative feeding unit, mixing chamber, and gas delivery pipe structure of Embodiment 1 of this utility model;

[0031] Figure 7 This is a schematic diagram of the overall structure of the feeding unit according to Embodiment 1 of this utility model;

[0032] Figure 8 This is another view of the overall structure of the feeding unit according to Embodiment 1 of this utility model;

[0033] Figure 9 This is a schematic diagram of the quantitative feeding unit structure according to Embodiment 1 of this utility model;

[0034] Figure 10 This is a schematic diagram of the construction method of Embodiment 1 of this utility model;

[0035] Figure 11 This is a schematic diagram illustrating the collaborative operation between Embodiment 1 of this utility model and the front-end.

[0036] Figure 12 This is a schematic diagram of the quantitative feeding unit structure in Embodiment 2 of this utility model;

[0037] Figure 13 This is a schematic diagram of the powder-gas injection assembly structure according to Embodiment 3 of this utility model;

[0038] Figure 14 for Figure 13 Enlarged illustration at the circled area

[0039] Figure 15 This is a front view of the overall structure of Embodiment 4 of this utility model;

[0040] Figure 16 This is a rear view of the overall structure of Embodiment 4 of this utility model;

[0041] Figure 17 This is a top view of the pneumatic conveying line of Embodiment 4 of this utility model;

[0042] Figure 18 This is a top view of the pressurization circuit of the conveying tank in Embodiment 4 of this utility model;

[0043] Figure 19 This is a schematic diagram of the construction method of Embodiment 4 of this utility model;

[0044] Figure 20 This is a schematic diagram of the powder-gas injection assembly structure in Embodiment 5 of this utility model;

[0045] Figure 21 This is a schematic diagram of the powder-gas injection assembly structure in Embodiment Six of this utility model;

[0046] Figure 22 This is a schematic diagram of the powder-gas injection assembly structure in Embodiment 7 of this utility model. Detailed Implementation

[0047] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0048] Example 1

[0049] like Figures 1-11As shown, this utility model provides a powder jetting pile backing system with air-lock pulse feeding, including an air supply unit 1, a material feeding unit 2, a quantitative feeding unit 6, a pneumatic conveying unit 3, a material storage unit 5, and a control unit 4 for coordinating the operation of each unit. The air supply unit 1 includes an air supply module consisting of an air compressor 11, an air storage tank 12, and a refrigerated dryer 13. The air dryer 13 has an inlet filter 141 at its inlet end and two outlet filters 142 at its outlet end to remove moisture and impurities from the compressed air. The output air path of the air supply unit 1 is configured to provide a conveying air source to the pneumatic conveying unit 3 and a pressurized air source to the material feeding unit 2. The material feeding unit 2 includes a material conveying tank body 210 and a guide pipe 216 connected to the outlet of the material conveying tank body 210. Specifically, as shown... Figure 12 As shown, in this embodiment, the longitudinal profile of the guide pipe 216 in the vertical plane including its own central axis is a bull's horn profile, which can reduce the flow resistance of powder, avoid powder blockage or uneven flow rate caused by abrupt changes in the flow channel, and ensure smooth conveying of powder from the feed tank to the metering chamber 62. The longitudinal profile shape can also be a right-angle profile or any other smoothly transitioned curved shape. The conveying tank body 210 is connected to the air supply unit 1 through the conveying tank air inlet pipe 214 to realize pressurized air supply, and the conveying tank air inlet pipe 214 is equipped with a conveying tank pressurization valve 413; the pneumatic conveying unit 3 includes an air supply pipe 303, a gas-solid mixing chamber 305 and a powder-gas conveying pipe 31; the air inlet end of the air supply pipe 303 is connected to the air outlet end of the air supply unit 1 to realize air supply, and the air outlet end of the air supply pipe 303 and the air outlet end of the quantitative feeding unit 6 converge to form the gas-solid mixing chamber 305. The gas-solid mixing chamber 305 is equipped with a pipe pressure relief hole for pressure relief, which facilitates further control of the pressure inside the pipe. The gas supply pipe 303 is equipped with a gas supply pipe switch valve 419. The control unit 4 controls the gas supply pipe switch valve 419 to open and close intermittently to provide a pulsed gas supply to the pneumatic conveying unit 3. This intermittent opening and closing control method is intended to effectively manage the total gas consumption from a single gas supply unit 1, so as to ensure that the gas supply unit 1 can simultaneously provide a continuous and stable pressurized gas supply to the conveying tank body 210, so that its internal pressure can be maintained at the preset working pressure. The inlet of the powder-gas conveying pipe 31 is connected to the gas-solid mixing chamber 305, and the outlet of the powder-gas conveying pipe 31 is connected to the piling machine 7; the quantitative feeding unit 6 includes a filling valve 61, a quantitative chamber 62 and an injection valve 63 connected in sequence, the inlet of the filling valve 61 is connected to the outlet of the guide pipe 216, and the outlet of the injection valve 63 is connected to the inlet of the gas-solid mixing chamber 305; the control unit 4 is configured to coordinate the opening and closing actions of the filling valve 61 and the injection valve 63 to achieve pulse quantitative feeding; the storage unit 5 is connected to the conveying tank body 210 and is used to replenish the conveying tank body 210.

[0050] Specifically, such as Figures 7-8As shown, the feeding unit 2 also includes a support frame 212, a connecting flange 211, a conveying tank exhaust pipe 215, a ladder, and a guide pipe unblocking hole 218. The conveying tank body 210 has a pressure vessel structure with a conical discharge structure at its lower end. The conveying tank body 210 is mounted on the support frame 212, and the bottom of the conveying tank body 210 is connected to the guide pipe 216 through the connecting flange 211. The guide pipe 216 is used to convey the powder to the gas-solid mixing chamber 305. The guide pipe unblocking hole 218 is connected to the guide pipe 216 to achieve an unblocking effect. The outer wall of the conveying tank body 210 is equipped with multiple vibrators 213, which ensure uniform powder conveying. The weight of the conveying tank body 210 is supported by three weighing sensors 401. The lower part of each weighing sensor 401 is fixed to the support frame 212, and the upper part is connected to the outer wall of the conveying tank body 210. This connection method allows the conveying tank body 210 to have a certain degree of lateral freedom of movement while transmitting vertical loads, thus ensuring the accuracy of weighing measurements. The top of the conveying tank body 210 is equipped with a feed valve 411 for replenishing powder curing agent. The conveying tank exhaust pipe 215 is located at the top of the conveying tank body 210 and is equipped with a conveying tank exhaust valve 414. The top of the conveying tank body 210 is also equipped with a conveying tank safety valve 415 to ensure the safety of air pressure inside the tank. A ladder is located on one side of the support frame 212 for easy climbing and maintenance. Vibrator 213, weighing sensor 401, feed valve 411, conveying tank pressurization valve 413, conveying tank exhaust valve 414 and conveying tank safety valve 415 are all electrically connected to the central control cabinet 42 of control unit 4.

[0051] Specifically, such as Figure 6As shown, the control unit 4 includes a sensor group, a valve group, and a central control cabinet 42; the sensor group 40 includes three weighing sensors 401 for monitoring the weight of the powder curing agent in the conveying tank body 210, a conveying tank pressure gauge 403 for monitoring the pressure in the conveying tank body 210, a gas tank pressure gauge 404 for the gas storage tank 12, and a main gas pipe pressure gauge 402 for monitoring the conveying pipeline; each weighing sensor 401 is fixed on the support frame 212, and the conveying tank body 210 is vertically pressed onto the weighing sensor 401, and the conveying tank pressure gauge 403 is installed on the conveying tank body 210; the gas tank pressure gauge 404 is installed on the top of the gas storage tank 12, and the main gas pipe pressure gauge 402 is installed at the output gas of the gas supply unit 1. Along the way, the valve group includes a conveying tank pressurization valve 413 and a conveying tank exhaust valve 414, a feed valve 411, a storage tank discharge valve 416, and a main air circuit switch valve 418 for regulating the pressure of the conveying tank body 210. The feed valve 411 is located at the top center of the conveying tank body 210, the conveying tank pressurization valve 413 is located on the conveying tank air inlet pipe 214, the conveying tank exhaust valve 414 is located on the conveying tank exhaust pipe 215, the storage tank discharge valve 416 is located at the bottom of the storage tank 50 of the storage unit 5, and the main air circuit switch valve 418 is located on the output air circuit of the air supply unit 1. A main air pipe manual valve is also provided on the output air circuit. The outlet end of the output air circuit forms a branch, which is connected to the air conveying pipe 303 and the conveying tank air inlet pipe 214 respectively.

[0052] The central control cabinet 42 is electrically connected to the valve assembly, sensor assembly, and the filling valve 61 and injection valve 63 of the quantitative feeding unit 6; the central control cabinet 42 is configured to periodically execute a quantitative feeding operation cycle including the following steps:

[0053] S1: Filling: The injection valve 63 of the quantitative feeding unit 6 is closed, while the filling valve 61 is opened, so that under the preset working pressure of the conveying tank body 210, the powder curing agent is drawn from the conveying tank body 210 through the guide...

[0054] The tube 216 is filled into the metering chamber 62 with a defined volume until the predetermined injection conditions are met;

[0055] S2: Injection: After the metering chamber 62 is filled, the filling valve 61 is closed, and the injection valve 63 is opened and closed once or multiple times according to the preset opening frequency and / or single opening duration parameters, so that the powder curing agent stored in the metering chamber 62 of the predetermined volume is pulsedly injected into the gas-solid mixing chamber 305 of the pneumatic conveying unit 3 under the pressure inside the metering chamber 62.

[0056] Specifically, such as Figure 5As shown, there is one gas delivery pipe 303. The central axis of the gas delivery pipe 303 intersects the central axis of the gas-solid mixing chamber 305, and the included angle is less than 60°, preferably 30°. This allows the conveying airflow to enter the mixing chamber at a better angle, enhancing the ability to entrain powder, improving the gas-solid mixing efficiency, and avoiding powder accumulation or insufficient conveying power caused by unreasonable airflow angle in traditional structures.

[0057] Specifically, such as Figure 9 As shown, the internal flow channel of the metering chamber 62 of the metering unit 6 is a variable diameter structure connected in sequence. The variable diameter structure includes an inlet expansion section connected to the outlet of the filling valve 61, an intermediate equal diameter metering section connected downstream of the inlet expansion section, and an outlet reduction section connected downstream of the intermediate equal diameter metering section and connected to the inlet of the injection valve 63.

[0058] Specifically, the inlet expansion section helps reduce the flow velocity of the powder curing agent entering from the guide pipe 216, reducing impact and disturbance, allowing the powder to fill the entire metering cavity 62 more smoothly and densely, improving the accuracy and repeatability of single metering. The intermediate constant-diameter metering section provides a precise volume reference, ensuring the geometric consistency of the powder curing dosage for each batch. The outlet reduction section, at the moment the injection valve 63 opens, creates an acceleration and focusing effect on the powder curing agent prepared to be discharged under high pressure within the metering cavity 62, resulting in a high-speed material flow with more concentrated energy and better directionality. This Venturi effect or similar throat effect helps increase the injection velocity and initial kinetic energy of the powder, enhancing its penetration and initial dispersion performance in the downstream gas-solid mixing chamber 305, and may improve the cut-off performance of the injection valve 63, reducing powder curing agent dripping or residue. Compared to a simple constant-diameter metering cavity, this "expansion-constant-reduction" structure, by optimizing the internal flow field, is more conducive to achieving rapid, accurate, and efficient pulsed metering.

[0059] Specifically, such as Figure 7As shown, the central control cabinet 42 of the control unit 4 is configured to dynamically control the opening and closing of the pressurizing valve 413 and the exhaust valve 414 of the conveying tank based on the pressure data fed back from the pressure gauge 403, so as to accurately maintain the pressure inside the conveying tank body 210 within the preset working pressure range. This stable upstream pressure aims to ensure that when the filling valve 61 opens according to the preset program to fill the metering chamber 62, the metering chamber 62 receives a consistent amount of powder curing agent and the same initial internal pressure each time. This ensures that in each spraying cycle when the subsequent spraying valve 63 opens according to the preset program, the amount of powder curing agent sprayed from the metering chamber 62 is highly consistent, thereby achieving overall quantitative feeding. The central control cabinet 42 adjusts the valve opening and closing in real time based on the pressure gauge feedback data to form a pressure closed-loop control, so that the pressure of the conveying tank is stabilized within the preset range. This stable pressure ensures that the metering chamber receives the same filling amount and initial pressure each time it is filled, thereby ensuring a highly consistent amount of powder sprayed in each cycle during spraying, achieving "high-precision metering".

[0060] Specifically, the central control cabinet 42 of the control unit 4 is further configured to, during or before filling the metering chamber 62 through the filling valve 61, activate the vibrator 213 on the outer wall of the conveying tank body 210 according to preset conditions or real-time monitoring of the powder curing agent flow status, to assist the powder curing agent in overcoming potential arching or poor flow, ensuring its smooth and rapid flow into the metering chamber 62. The control unit 4 activates the vibrator 213 according to preset conditions or real-time monitoring of the powder flow status (e.g., judging whether the flow is smooth by changes in the data from the weighing sensor 401), avoiding energy waste or powder segregation caused by blind vibration, further improving the smoothness and reliability of the feeding (optimizing the shortcomings of traditional equipment requiring manual intervention to solve flow problems in the background technology).

[0061] Specifically, such as Figure 4 As shown, the storage unit 5 includes a storage tank 50 and a feeding mechanism for conveying the powder curing agent from the storage tank 50 to the conveying tank body 210. The feeding mechanism includes a feeding auger 51 corresponding to the storage tank 50, an auger motor 52 for driving the feeding auger 51, and a wire rope 53 for fixing the auger motor 52. The storage tank 50 is provided with a storage tank discharge valve 416 at the bottom. The control unit 4 automatically controls the start and stop of the feeding mechanism and the opening and closing of the storage tank discharge valve 416 according to the signal of the weighing sensor 401 on the conveying tank body 210, so as to realize the automatic replenishment of material to the conveying tank body 210 on demand.

[0062] In this embodiment, combined with Figure 10 and Figure 11 The paper also discloses a construction method (single air source) for the powder jet grouting pile back-end of the above-mentioned air-lock pulse feeding system, which includes the following standard steps:

[0063] S1. Operation Parameter Setting: Set the background operation parameters on the central control cabinet 42. The parameters include: quantitative feeding unit 6

[0064] The working cycle includes the filling time of the metering chamber 62, the opening and closing frequency and / or single opening time of the injection valve 63, the preset working pressure of the conveying tank body 210, the weight of the conveying tank body 210 to be loaded, the opening and closing cycle of the air conveying pipe switch valve 419, and the residual threshold of the powder curing agent used to start the automatic replenishment of the conveying tank body 210.

[0065] S2. Initial feeding of the conveying tank: Close the pressurization valve 413 of the conveying tank, open the exhaust valve 414 of the conveying tank, and wait for the conveying tank pressure to reach the desired level.

[0066] Table 403 shows that its internal pressure is zero. Open the feed valve 411 at the top of the conveying tank body 210, and at the same time start the auger motor 52 connected to the corresponding storage tank 50 in the storage unit 5 and open the storage tank discharge valve 416 at the bottom of the storage tank 50 to transport the powder curing agent from the storage tank 50 to the conveying tank body 210. When the weight monitored by the weighing sensor 401 on the conveying tank body 210 reaches the set weight to be loaded, close the storage tank discharge valve 416, stop the auger motor 52, close the feed valve 411 and the conveying tank exhaust valve 414 in sequence.

[0067] S3. System Start-up, Pre-pressurization and Standby: Start the air supply unit 1, open the pressurization valve 413 of the conveying tank, pressurize the conveying tank body 210 to the preset working pressure, and the central control cabinet 42 dynamically maintains the pressure according to the feedback of the conveying tank pressure gauge 403; after receiving the ready signal sent by the front-end piling machine 7, open the main air circuit switch valve 418, and the central control cabinet 42 starts the air supply pipe switch valve 419 to intermittently open and close according to the preset cycle, and the background enters the spraying standby state;

[0068] S4. Execute quantitative feeding cycle: After receiving the start spraying operation command from the front-end piling machine 7, the central control cabinet 42 of the control unit 4 drives the filling valve 61 and spraying valve 63 of the quantitative feeding unit 6 to open and close periodically and in a coordinated manner (it can also coordinate the opening time of the spraying valve to be as close as possible to the closing period of the air supply pipe switch valve 419, which is more conducive to feeding), repeating this quantitative feeding operation cycle to achieve continuous and quantitative powder feeding to the front-end piling machine 7.

[0069] Supply. This operation includes the following steps:

[0070] (a) Filling: Close the injection valve 63 and then open the filling valve 61. Under the preset working pressure of the conveying tank body 210, the powder curing agent is filled from the conveying tank body 210 through the guide pipe 216 into the metering chamber 62 for the set filling time.

[0071] (b) Injection: Close the filling valve 61, and control the injection valve 63 to open and close intermittently or open once according to the preset opening and closing frequency and / or single opening duration, so that the batch of powder curing agent in the metering chamber 62 is injected into the gas-solid mixing chamber 305 of the pneumatic conveying unit 3 under the pressure inside the metering chamber 62 and is fully mixed with the compressed air from the air conveying pipe 303 before being conveyed.

[0072] S5. On-demand replenishment of the conveying tank: During the quantitative feeding operation, the powder solidifying agent inside the conveying tank body 210 is continuously monitored.

[0073] Weight; when the weighing sensor 401 detects that the remaining amount of powder curing agent is lower than the powder curing agent remaining amount threshold set in step S1, the central control cabinet 42 sends a command to the front-end piling machine 7 to request to stop drilling and keep idling; after the front-end piling machine 7 responds and enters the idling state, the central control cabinet 42 pauses the quantitative feeding cycle, and then executes the feeding procedure to the material tank body 210 in step S2; after the feeding is completed, the background returns to the standby state and notifies the front-end piling machine 7 that it can resume operation;

[0074] S6. Single Pile Operation Completed: When the operation completion command is received from the front-end pile driver 7, the central control cabinet 42 stops.

[0075] The material is fed in a quantitative cycle, all valves are closed, and the current operation is completed. When the front-end pile driver 7 moves to issue a new pile operation instruction, the operation process of steps S1 to S6 is repeated until all the predetermined pile positions are completed.

[0076] Example 2

[0077] This embodiment (e.g.) Figure 12 The structure of the unit shown is largely similar to that of the embodiment, with the key difference being that the metering chamber 62 of the metering unit 6 in this embodiment is a straight tube with a constant diameter. This provides a simpler and more economical airlock-type metering solution that can also reliably fill and discharge powder, meeting the basic requirements for metering.

[0078] The detailed construction method of the construction backend in this embodiment is the same as or substantially the same as the implementation method described in Embodiment 1, and will not be repeated here.

[0079] Example 3

[0080] Embodiment 3 is another implementation of this utility model, such as... Figure 13 , 14As shown, the general structure of this embodiment is the same as that of Embodiment 1. The only difference is that, in order to achieve a better mixing effect, the gas-solid mixing chamber 305 adopts a variable diameter structure consisting of a contraction section 305.a at the inlet end, a uniform diameter mixing section 305.b in the middle, and a divergence section 305.c at the outlet end connected in sequence. The cross-section of the contraction section 305.a is gradually narrowing, the mixing section 305.b is a straight pipe section with a uniform cross-section, and the cross-section of the divergence section 305.c is gradually expanding.

[0081] Specifically, in this variable-diameter structure, the converging section 305.a at the inlet end increases the velocity of the gas-solid two-phase flow by reducing the flow area, enhancing the turbulence intensity and shear effect of the airflow, thereby effectively breaking up powder particle agglomerations and promoting their initial radial dispersion in the airflow. The subsequent equal-diameter mixing section 305.b provides the necessary length and time, allowing the powder particles initially dispersed in the converging section 305.a to be further fully mixed under continuous turbulence, achieving a high degree of macroscopic and microscopic uniformity. Finally, the diverging section 305.c at the outlet end gradually expands the flow area to reduce the velocity of the gas-solid two-phase flow, stabilize the flow pattern, and further refine the uniformity of particle distribution across the cross-section, while also contributing to stable transport in the subsequent powder-gas conveying pipe 31. This specific variable-diameter structure of the gas-solid mixing chamber 305, characterized by "contraction-accelerated premixing, equal-diameter full mixing, and divergence-stabilized homogenization," achieves more thorough and uniform mixing of the gas and solid phases than traditional equal-diameter straight pipes through the optimized combination and synergistic effect of each section's function. This ensures that the powder curing agent delivered to the front-end drilling rig has high dispersion and concentration consistency in the airflow, which is of great significance for improving the uniformity of spraying, ensuring the quality of the pile body and the stability of the entire construction process.

[0082] The detailed construction method of the construction backend in this embodiment is the same as or substantially the same as the implementation method described in Embodiment 1, and will not be repeated here.

[0083] Example 4

[0084] A key feature of this embodiment is that its gas supply unit 1 employs a design of two sets of parallel gas supply subsystems with essentially identical structures and functions. For clarity and conciseness, the following notation rules will be used in the following description and figures: For similar components present in all parallel subsystems (such as gas pipe 303), a basic number (e.g., 303) can be used when describing their general structure or function; however, when it is necessary to distinguish components from different subsystems or describe their alternating operation logic (especially in the construction method section), a specific number with a suffix (e.g., 303.a, 303.b) will be used. The illustrations of individual subsystems in the figures are generally representative and applicable to other parallel subsystems, unless otherwise stated.

[0085] Embodiment 4 is another implementation of this utility model, such as... Figures 15 to 19 As shown, the general structure of this embodiment is the same as that of Embodiment 1. The only difference is that the air supply unit 1 in this embodiment includes two sets of air supply sub-units arranged in parallel, namely the first air supply sub-unit 1.a and the second air supply sub-unit 1.b. Each set of air supply sub-units includes an air compressor 11, an air storage tank 12 and a refrigerated dryer 13 connected in sequence from the air inlet to the air outlet. The output air path of the first air supply sub-unit 1.a provides the air source for the pneumatic conveying unit 3. In this embodiment, there are two air supply pipes 403 (the first air supply pipe 303.a and the second air supply pipe 303.b). The air inlet ends of the two air supply pipes 403 converge and are connected to the output air path of the first air supply sub-unit 1.a. The air outlet ends of the two air supply pipes 403 are connected to the gas-solid mixing chamber 405. The central axis of each air supply pipe 403 intersects the central axis of the gas-solid mixing chamber 405 at an angle of 30°. Two gas supply pipes 403 are symmetrically distributed circumferentially along the gas-solid mixing chamber 405; and in this embodiment, the gas-solid mixing chamber 405 adopts a pipe section structure of equal diameter. The second gas supply subunit 1.b provides a pressurized gas source to the conveying tank body 210 in the feeding unit 2 to maintain pressure, and the air inlet end of the conveying tank air inlet pipe 214 is connected to the output air path of the second gas supply subunit 1.b. By setting up an independent second air supply path specifically for providing strong pneumatic conveying power, and an independent first air supply path specifically for maintaining the high pressure stability of the conveying tank body, and combining it with an airlock-type quantitative feeding unit 6 consisting of a filling valve, a precisely sized quantitative chamber 62, and a fast-opening and closing injection valve 63, along with corresponding automated control strategies, the amount of powder discharged from the quantitative chamber 62 in each working cycle is precisely controlled while ensuring that the main conveying tank has a constant and sufficient discharge pressure. The quantitative powder is then efficiently and stably conveyed to the piling machine through an independent strong airflow, thus providing a precise, reliable, intelligent, and efficient back-end technical solution for large-diameter, deep DJM pile foundation projects.

[0086] In this embodiment, combined with Figures 15 to 19 The paper also discloses the construction method (dual air source) for the powder jet grouting pile back-end using air-lock pulse feeding, including the following standard steps:

[0087] S1. Setting operating parameters: Set background operating parameters on the central control cabinet 42. The parameters include: the working cycle of the quantitative feeding unit 6, including the filling time of the quantitative chamber 62, the opening and closing frequency and / or single opening time of the injection valve 63, the preset working pressure of the conveying tank body 210, the weight of the conveying tank body 210 to be fed, and the residual threshold of the powder curing agent used to start the automatic replenishment of the conveying tank body 210.

[0088] S2. Initial feeding of the conveying tank: Close the pressurization valve 413 of the conveying tank, open the exhaust valve 414 of the conveying tank, and wait for the pressure gauge 403 of the conveying tank to show that its internal pressure is zero. Open the feed valve 411 at the top of the conveying tank body 210, and at the same time start the auger motor 52 connected to the corresponding storage tank 50 in the storage unit 5 and open the discharge valve 416 at the bottom of the storage tank 50 to transport the powder curing agent from the storage tank 50 to the conveying tank body 210. When the weight monitored by the weighing sensor 401 on the conveying tank body 210 reaches the set weight to be fed, close the discharge valve 416 of the storage tank, stop the auger motor 52, close the feed valve 411 and the exhaust valve 414 of the conveying tank in sequence.

[0089] S3. System Start-up, Pre-pressurization and Standby: Start the second air supply subunit 1.b of air supply unit 1, open the pressurization valve 413 of the material tank, pressurize the material tank body 210 to the preset working pressure, and the central control cabinet 42 dynamically maintains the pressure according to the feedback of the material tank pressure gauge 403; after receiving the ready signal sent by the front-end piling machine 7, start the first air supply subunit 1.a of air supply unit 1, and open the main air circuit switch valve 418, and the background enters the spraying standby state;

[0090] S4. Execute quantitative feeding cycle: After receiving the start spraying operation command issued by the front pile driver 7, the central control cabinet 42 of the control unit 4, i.e. the above-mentioned filling and spraying configuration, drives the filling valve 61 and spraying valve 63 of the quantitative feeding unit 6 to periodically and coordinately open and close, and carry out quantitative feeding operation. This operation includes: (1) Filling, controlling the spraying valve 63 of the quantitative feeding unit 6 to be in the closed state, and at the same time opening the filling valve 61, so that under the high pressure of 0.6MPa of the conveying tank body 210, the powder curing agent is discharged from the conveying tank body 210 through the guide pipe 2 16 is filled into the metering chamber 62 for 2 seconds; (2) Spraying: after the metering chamber 32 is filled, the filling valve 61 is closed and the spray valve 63 is opened and closed 6 times intermittently for a total duration of 3 seconds. The powder curing agent stored in the metering chamber 62 is then pulsedly sprayed into the gas-solid mixing chamber 305 of the pneumatic conveying unit 3 under the pressure inside the metering chamber 62 and fully mixed with the compressed air from the air pipe 303 before being conveyed. This metering cycle is repeated to achieve continuous and metered powder supply to the front pile driver 7. S5. Material replenishment to the conveying tank as needed: During the quantitative feeding operation, the weight of the powder curing agent in the conveying tank body 210 is continuously monitored; when the weighing sensor 401 detects that the remaining amount of powder curing agent is lower than the powder curing agent remaining amount threshold set in step S1, the central control cabinet 42 sends a command to the front-end piling machine 7 to request to stop drilling and keep it idling; after the front-end piling machine 7 responds and enters the idling state, the central control cabinet 42 pauses the quantitative feeding cycle and then executes the feeding procedure to the conveying tank body 210 in step S2; after the feeding is completed, the background returns to the standby state and notifies the front-end piling machine 7 that the operation can be resumed;

[0091] S6. Single pile operation completed: When the operation completion instruction is received from the front-end pile driver 7, the central control cabinet 52 stops the quantitative feeding cycle, closes all valves, and completes the operation; when the front-end pile driver 7 moves to issue a new pile operation instruction, the operation process of steps S1 to S6 is repeated until all predetermined pile positions are constructed.

[0092] Example 5

[0093] This embodiment (e.g.) Figure 20 The structure of the pneumatic conveying unit 3 is similar to that of the embodiment 4, with the key difference being that only one gas delivery pipe 303 is provided in the pneumatic conveying unit 3 for introducing high-pressure gas into the gas-solid mixing chamber 305 and mixing it with the powder from the metering chamber 62. This design simplifies the structure, reduces costs, and is suitable for working conditions with moderate requirements for mixing uniformity, making it an economical implementation of this utility model.

[0094] The detailed construction method of the construction backend described in this embodiment is the same as or substantially the same as the implementation method described in Embodiment 1, and will not be repeated here.

[0095] Example 6

[0096] This embodiment (e.g.) Figure 21 The structure of the two gas pipes 303 is similar to that of the embodiment 4, but the key difference is that the two gas pipes 303 are not arranged in the same cross section along the circumference of the gas-solid mixing chamber 305, but are arranged on both sides at a certain distance from each other along its axis.

[0097] This design, where the gas delivery pipes 303 are spaced axially along the gas-solid mixing chamber 305, allows high-pressure delivery gas to be injected into the powder flow in stages at different axial positions within the gas-solid mixing chamber 305. For example, the first gas delivery pipe 303.a, located near the injection valve 63, can primarily be responsible for the initial impact dispersion and fluidization of the powder, while the second gas delivery pipe 303.b, located downstream, can be used to supplement the gas volume, further increasing the velocity of the gas-solid two-phase flow and enhancing the degree of turbulent mixing. This embodiment provides another effective way to control the dynamic characteristics of the gas-solid mixing process by changing the arrangement strategy of the gas delivery pipes 303 (axial spacing rather than circumferential symmetry).

[0098] The detailed construction method of the construction backend described in this embodiment is the same as or substantially the same as the implementation method described in Embodiment 1, and will not be repeated here.

[0099] Example 7

[0100] This embodiment (e.g.) Figure 22 As shown, the gas-solid mixing chamber 305 has a similar overall structure to that of Example 4, but the key difference is that, to achieve a better mixing effect, the gas-solid mixing chamber 305 adopts a variable diameter structure consisting of a converging section 305.a at the inlet end, a uniform diameter mixing section 305.b in the middle, and a diverging section 305.c at the outlet end connected in sequence. The effect of the variable diameter is the same as that of Example 3.

[0101] The detailed construction method of the construction backend described in this embodiment is the same as or substantially the same as the implementation method described in Embodiment 1, and will not be repeated here.

Claims

1. A powder jet grouting support system with air-lock pulse feeding, characterized in that, The system includes an air supply unit (1), a material supply unit (2), a quantitative feeding unit (6), a pneumatic conveying unit (3), and a control unit (4) for coordinating the operation of each unit. The material supply unit (2) includes a conveying tank body (210) and a guide pipe (216) connected to the outlet of the conveying tank body (210). The conveying tank body (210) is connected to the air supply unit (1) through the conveying tank air inlet pipe (214) to achieve pressurized air supply. The pneumatic conveying unit (3) includes at least one air supply pipe (303) and a gas-solid mixing chamber (305). Each air supply pipe (303) has... The air inlet is connected to the air supply unit (1) and realizes the air source delivery. The air outlet of the air supply pipe (303) and the air outlet of the quantitative feeding unit (6) are connected to the gas-solid mixing chamber (305). The quantitative feeding unit (6) includes a filling valve (61), a quantitative chamber (62) and an injection valve (63) connected in sequence. The filling valve (61) is connected to the outlet of the guide pipe (216), and the injection valve (63) is connected to the inlet of the gas-solid mixing chamber (305). The control unit (4) is configured to coordinate the opening and closing actions of the filling valve (61) and the injection valve (63) to realize pulse quantitative feeding.

2. The air-lock pulse feeding powder jetting pile backing system according to claim 1, characterized in that, The air supply unit (1) includes an air supply module consisting of an air compressor (11), an air storage tank (12), and a refrigerated dryer (13) in sequence. The output air path of the air supply module is configured to simultaneously provide a conveying air source to the pneumatic conveying unit (3) and a pressurized air source to the conveying tank body (210) of the feeding unit (2). The air inlet end of the conveying tank inlet pipe (214) and the air inlet end of the conveying pipe (303) are connected to the output air path of the air supply module. The conveying pipe (303) is provided with a conveying pipe switch valve (419). The control unit (4) controls the conveying pipe switch valve (419) to open and close intermittently to provide a pulsed conveying air source to the pneumatic conveying unit (3).

3. The air-lock pulse feeding powder jetting pile backing system according to claim 1, characterized in that, The air supply unit (1) includes two sets of air supply modules consisting of an air compressor (11), an air tank (12), and a refrigerated dryer (13) in sequence. One set of air supply modules is used to provide a conveying air source to the pneumatic conveying unit (3). The air inlet end of the air conveying pipe (303) is connected to the output air path of the air supply module. The other set is used to provide a pressurized air source to the feeding unit (2) to maintain the feeding unit (2) at a preset working pressure. The air inlet end of the air inlet pipe (214) of the feeding tank is connected to the output air path of the air supply module.

4. The air-lock pulse feeding powder jet grouting backing system according to claim 1, characterized in that, The feeding unit (2) also includes a support frame (212), a connecting flange (211), and a conveying tank exhaust pipe (215); the conveying tank body (210) is mounted on the support frame (212), the bottom of the conveying tank body (210) is connected to the guide pipe (216) through the connecting flange (211), and a vibrator (213) is provided at the bottom of the conveying tank body (210); the conveying tank exhaust pipe (215) is connected to the top of the conveying tank body (210).

5. The air-lock pulse feeding powder jetting pile backing system according to claim 4, characterized in that, The control unit (4) includes a sensor group, a valve group, and a central control cabinet (42); the sensor group includes a weighing sensor (401) for monitoring the weight of the powder curing agent in the conveying tank body (210) and a conveying tank pressure gauge (403) for monitoring the pressure inside the tank. The weight of the conveying tank body (210) is supported by at least three weighing sensors (401), each weighing sensor (401) is fixed on the support frame (212), and the conveying tank body (210) is vertically pressed on the weighing sensor (401). The conveying tank pressure gauge (403) is installed on the conveying tank body (210); the valve group includes a feed valve (411), a conveying tank pressurization valve (413), and a conveying tank exhaust valve. (414), main air circuit switch valve (418) and air supply pipe switch valve (419); the feed valve (411) is installed on the body of the feed tank (210) and is used for replenishing the powder curing agent; the feed tank pressurization valve (413) is installed on the feed tank air inlet pipe (214); the feed tank exhaust valve (414) is installed on the feed tank exhaust pipe (215); the main air circuit switch valve (418) is installed on the output air circuit of the air supply unit (1); the air supply pipe switch valve (419) is installed on the air supply pipe (303); the central control cabinet (42) is installed on the support frame (212); the central control cabinet (42) is electrically connected to the vibrator (213), valve group, sensor group and the quantitative feeding unit (6).

6. The air-lock pulse feeding powder jetting pile backing system according to claim 5, characterized in that, The central control cabinet (42) of the control unit (4) is configured to dynamically control the opening and closing of the pressurizing valve (413) and the exhaust valve (414) of the conveying tank based on the pressure data fed back by the pressure gauge (403) of the conveying tank, so as to accurately maintain the pressure in the conveying tank body (210) within the preset working pressure range; this stable upstream pressure is intended to ensure that when the filling valve (61) opens according to the preset program to fill the metering chamber (62), the metering chamber (62) can obtain a consistent amount of powder curing agent and the same initial internal pressure each time, thereby ensuring that the subsequent injection valve ( 63) During each spraying cycle started according to the preset program, the amount of powder solidified agent sprayed from the metering chamber (62) is highly consistent, thereby achieving overall quantitative feeding; the central control cabinet (42) of the control unit (4) is further configured to, during or before filling the metering chamber (62) through the filling valve (61), start the vibrator (213) on the outer wall of the conveying tank body (210) in a timely manner according to the preset conditions or the real-time monitored flow state of the powder solidifying agent, so as to assist the powder solidifying agent in overcoming potential arching or poor flow, and ensure that it flows smoothly and quickly into the metering chamber (62).

7. The air-lock pulse feeding powder jetting pile backing system according to claim 1, characterized in that, The central axis of the gas delivery pipe (303) intersects the central axis of the gas-solid mixing chamber (305), and the included angle is less than 60°.

8. The air-lock pulse feeding powder jetting pile backing system according to claim 1, characterized in that, The gas-solid mixing chamber (305) includes a variable diameter structure consisting of a converging section (305.a) at the inlet end, a mixing section (305.b) in the middle, and a diverging section (305.c) at the outlet end connected in sequence. The converging section (305.a) has a gradually narrowing cross-section, the mixing section (305.b) is a straight pipe section with a constant cross-section, and the diverging section (305.c) has a gradually expanding cross-section.

9. The air-lock pulse feeding powder jetting pile backing system according to claim 1, characterized in that, The longitudinal profile shape of the guide tube (216) in the vertical plane containing the central axis of the metering cavity (62) includes, but is not limited to, a right-angled profile, a bull-horn profile, or a curved shape with any smooth transition.

10. The air-lock pulse feeding powder jet grouting backing system according to claim 1, characterized in that, The internal flow channel of the metering chamber (62) is a variable diameter structure, and the variable diameter structure includes, from inlet to outlet, an inlet expansion section connected to the outlet of the filling valve (61), an intermediate equal diameter metering section, and an outlet reduction section connected to the inlet of the injection valve (63).

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