Powder spraying pile background for air source reuse airlock type pulse feeding and construction method

Abstract

The invention discloses an air source reuse airlock type pulse feeding powder spraying pile background and a construction method, and aims to solve the vicious circle of'pipe blockage-impact 'caused by intermittent regulation and control of air supply in economical single air source pulse conveying. According to the background, an air supply structure comprising a main air path and an auxiliary air path is constructed under a single air source, and the core innovation of the background is'air source reuse ': a material conveying tank is used as an auxiliary air source, and in the intermittent period of conveying of the main path, air flow is led out from the auxiliary path to maintain powder in a pipe to suspend in a critical state at the lowest energy consumption, so that the operation contradiction that pressure maintaining and material supplying maintaining are difficult to consider at the same time is solved. The invention further discloses a construction method of the background. By means of the method, on the premise that extra power cost is not increased, the pipe blocking problem of single-gas-source pulse conveying is thoroughly solved; and high reliability and stability comparable to those of a double-gas-source system are achieved at the economic cost of a single gas source, the automatic control level is remarkably improved, and the overall stability, reliability and intelligence level under the long-distance and large-depth working conditions can be reliably guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of powder injection pile construction equipment, and in particular to a powder injection pile backstage with air source reuse and air-lock pulse feeding and a construction method. Background Art

[0002] As an efficient in-situ reinforcement method for soft soil foundations, the quality of powder-injection mixing pile technology is closely related to whether the powder as a curing agent can be accurately and evenly sprayed into the soil. Therefore, a reliable and precise powder supply system in the construction background is the key prerequisite for the successful application of this technology. In the traditional construction background of powder-injection piles, there is a major technical bottleneck in the quantitative feeding link. The industry mostly uses mechanical devices such as rotary feeders, but the output of such devices is easily affected by various factors such as material level, back pressure, powder properties and mechanical wear, resulting in a large deviation between the actual powder spraying amount and the design value, making it difficult to meet the precise quantitative requirements of high-quality pile foundations.

[0003] To address the aforementioned material unloading accuracy challenges, the applicant proposed an innovative air-locked quantitative unloading solution in another patent application filed on the same date. This solution, utilizing a dual-valve structure consisting of a "charging valve-dosing chamber-injection valve" and applying the principle of volumetric batch metering, achieved a significant breakthrough in unloading accuracy, successfully overcoming the inherent shortcomings of traditional mechanical devices. This solution now meets the precision and reliability requirements of conventional construction teams.

[0004] However, arranging a power source for this high-precision blanking technology presents a critical trade-off. Technically, a dual-compressor configuration—one independent air supply unit provides constant pressure for the feed tank, while another independent air supply unit provides strong power for pneumatic conveying—could perfectly resolve the air volume distribution conflict. However, this solution would complicate the equipment configuration, significantly increasing acquisition costs, energy consumption, transportation, installation, and maintenance expenses.

[0005] Therefore, a more economical option is to use a single air compressor. However, to avoid excessively low total air pressure due to continuous air delivery, which would interfere with the stable pressurization of the feed tank, a pulsed air supply strategy based on "intermittent opening and closing" of the main air pipeline becomes an inevitable choice. However, in practice, this also brings a new operational contradiction that requires careful consideration:

[0006] Setting the air supply intermittent time is a dilemma. If the intermittent time is set too short, while the front-end powder spraying can be continuous, the main air source (air storage tank) will not have enough time to recover its pressure. This will cause the total air circuit pressure to continue to drop, and the pressure in the feed tank will also become low and unstable. Unstable tank pressure will directly undermine the premise of air-lock quantitative feeding, causing the amount of powder charged to the metering chamber to fluctuate each time, losing accuracy. At the same time, if the initial pressure in the metering chamber is too low, the subsequent outward spray will be weak.

[0007] Conversely, setting the pause time too long ensures the main air source's pressure is restored, but prolonged air supply interruptions can lead to prolonged intervals between powder spraying by the front-end drill, directly impacting the uniformity of the finished pile. Furthermore, and perhaps more critically, the powder-air two-phase flow in the conveying pipeline will rapidly settle due to the prolonged loss of kinetic energy. This is particularly true in vertical or inclined risers, where accumulation can easily lead to pipeline blockages. Furthermore, restarting the already settled material flow requires instantaneous high air pressure and volume, which in turn significantly impacts the already strained single-source air system, creating a vicious cycle.

[0008] Therefore, how to inherit the advantages of high-precision air-lock unloading while avoiding the high cost of the dual air compressor solution, and economically and effectively solve the vicious cycle of "pipe blocking-impact" and complex operational contradictions caused by powder sedimentation in single air compressor pulse conveying, is a technical problem that needs to be solved urgently in this field. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a single-gas source power solution that is both economical and highly reliable for the high-precision air-lock quantitative feeding technology proposed by the applicant. As described in the background technology, when the high-precision feeding technology is combined with the economical single-gas source configuration, its pulsed gas supply strategy will fall into a "dilemma" operational contradiction: if the intermittent time is shortened to ensure feeding, the pressure stability of the feeding tank will be sacrificed due to insufficient pressure of the main gas source, thereby affecting the feeding accuracy and injection capacity; on the contrary, if the gas supply intermittent time is extended to ensure the pressure recovery of the main gas source, that is, the gas storage tank, not only will there be a risk of damage to the uniformity of the pile body, but it will also cause the powder in the conveying pipeline to settle due to loss of kinetic energy, thereby triggering a vicious cycle of "blocking pipe-impact" - that is, the powder that tends to settle needs huge instantaneous air pressure to restart the suspended conveying state (especially in the rising stage of the conveying pipeline), which in turn causes a huge impact on the already tense single-gas source system. Therefore, the core technical problem that the present invention aims to solve is: how to break through the operational bottleneck of the above-mentioned single-source pulse gas supply on the basis of inheriting the advantages of air-locked high-precision blanking, and realize a truly stable and reliable single-source gas delivery solution that allows the main gas source, i.e., the gas tank, sufficient time to restore the pressure and ensures that the pipeline is unobstructed during the delivery interval.

[0010] In order to solve the above problems, the present invention provides a powder spray pile background and construction method with air source reuse and air-lock pulse feeding. The main purpose of the present invention is to propose an innovative system architecture and a staged coordinated air supply control strategy. The core of the present invention is to cleverly realize "air source reuse" by adding an auxiliary air circuit: that is, during the interval of pulsed strong conveying in the main air circuit, the existing pressurized space of the conveying tank itself is used as an auxiliary air source to lead out a small auxiliary air flow to maintain the minimum energy conditions required for the powder in the conveying pipeline to maintain a suspended flow state. The present invention aims to completely solve the pipe blocking risks and operational contradictions of single-source pulse conveying without increasing additional power costs through this innovative air source reuse strategy and the time-sharing collaboration design of the main and auxiliary air circuits, and provide a technical solution for powder spray pile construction with more precise material feeding, more reliable conveying, more intelligent control, and significant economic benefits.

[0011] The invention relates to a powder injection pile backstage with air source reuse and air lock pulse feeding, comprising an air supply unit, a feeding unit, a quantitative unloading unit, a pneumatic conveying unit, a material storage unit and a control unit for controlling the coordinated operation of each unit; the output air path of the air supply unit is configured to provide a conveying air source to the pneumatic conveying unit and a pressurized air source to the feeding unit; the feeding unit comprises a feeding tank body, a guide pipe connected to the discharge port of the feeding tank body; the quantitative unloading unit is connected to the outlet of the guide pipe; the pneumatic conveying unit comprises at least one air delivery pipe, an air-solid mixing chamber and a powder-air delivery pipe; the air inlet end of each air delivery pipe is connected to the air outlet end of the air supply unit The gas source is transported on the air outlet path, and the air outlet end of each air supply pipe is connected to the discharge end of the quantitative feeding unit and then connected to the gas-solid mixing chamber; the control unit is configured to coordinate the opening and closing actions of the quantitative feeding unit to achieve pulsed quantitative feeding; the inlet of the powder gas conveying pipe is connected to the outlet of the gas-solid mixing chamber; a tank air inlet pipe is connected between one of the air supply pipes and the tank body, and the tank air inlet pipe forms a two-way air path between the two to pressurize the tank body, or reversely transport the high-pressure gas in the tank body through the tank air inlet pipe, the air supply pipe, and the gas-solid mixing chamber to the powder gas conveying pipe in sequence. Through the "gas source reuse" design, the output gas path of the air supply unit provides power for pneumatic conveying and pressurizes the tank; at the same time, a two-way air path is formed through the tank air inlet pipe to realize reverse transport of the high-pressure gas from the tank to the powder gas conveying pipe. The high-pressure gas from the feed tank is used as an auxiliary gas source, which is then fed back to the delivery pipe during the main gas flow interval to maintain powder suspension. This fundamentally solves the problems of powder sedimentation and pipeline blockage caused by gas supply interruptions during single-source pulse delivery. The bidirectional gas flow design not only meets the feed tank's pressurization requirements, but also releases gas when pressure is too high, preventing tank pressure fluctuations from affecting subsequent quantitative feeding accuracy.

[0012] A single air pipe control method for the background of powder injection piles based on the above-mentioned air source reuse air-lock pulse feeding, wherein a main air circuit switch valve is provided on the output air circuit of the air supply unit; an air pipe switch valve is provided on each of the air pipes. When the pneumatic conveying unit is a single air pipe, the control unit is further configured to execute a staged coordinated air supply strategy, which includes a main air circuit conveying stage and an auxiliary air circuit conveying stage. The two stages share a common air pipe and switch between the two stages periodically or according to the system pressure state: S1: In the main air circuit conveying stage: the control unit controls the open state and intermittently opens and closes the air pipe switch valve according to the preset main conveying frequency to provide a pulsed air supply. The main conveying gas source is used to convey the powder curing agent ejected from the quantitative feeding unit at high speed; S2: in the auxiliary gas line conveying stage: when the gas pipe switch valve is in the closed period of intermittent gas supply in the main gas line conveying stage and when it is detected that the pressure in the feed tank body is higher than a preset safety threshold, the control unit performs a set of linkage operations, including: first closing the main gas line switch valve to isolate the gas supply unit to restore the pressure; then opening the feed tank pressurizing valve to introduce the high-pressure gas from the feed tank body into the shared gas pipe through the feed tank air inlet pipe; and again pulse-opening and closing the same gas pipe switch valve according to the preset auxiliary gas supply frequency to send out the auxiliary gas source to maintain the critical suspension conveying state of the powder. In the single gas pipe scenario, by time-sharing multiplexing the gas pipe, it is ensured that the main gas source (gas supply unit) has sufficient time to restore the pressure (solving the problem of "main gas source pressure continues to drop" in the background technology), and the powder is kept suspended by the feed tank gas to avoid sedimentation and pipe blockage. The pulse conveying in the main stage ensures the continuity of powder spraying at the front stage, and the residual pressure of the feeding tank is used in the auxiliary stage to maintain the lowest suspension energy consumption, solving the dilemma of "interval time is too short / too long" (short means insufficient pressure, long means sedimentation and pipe blocking).

[0013] A method for controlling multiple air pipes in the background of a powder injection pile based on the above-mentioned air source reuse and air-lock pulse feeding, wherein a main air circuit switch valve is provided on the output air circuit of the air supply unit; an air circuit switch valve is provided on each of the air pipes, and when the pneumatic conveying unit is composed of two air pipes, namely the first air pipe and the second air pipe, the air pipe switch valves are the first air pipe switch valve provided on the first air pipe and the second air pipe switch valve provided on the second air pipe; the control unit is further configured to execute a staged coordinated air supply strategy, which includes a main air circuit conveying stage and an auxiliary air circuit conveying stage, and switches between the two stages periodically or according to the system pressure state: S1, in the main air circuit conveying stage: the control unit controls the main air circuit switch valve to be in an open state , and intermittently open and close the first gas pipeline switch valve to provide a pulsed main conveying gas source for high-speed conveying of the powder curing agent ejected from the quantitative unloading unit; S2, in the auxiliary gas line conveying stage: when the first gas pipeline switch valve is in the closed state and the pressure in the feed tank body is detected to be higher than a preset safety threshold, the control unit performs a set of linkage operations, including: closing the main gas line switch valve to isolate the gas supply unit from the conveying pipeline, so that it can efficiently restore the pressure in the gas supply unit; and simultaneously controlling the second gas pipeline switch valve to open and close in pulses, drawing high-pressure gas from the feed tank body through the feed tank inlet pipe as an auxiliary gas source, and using the lowest energy consumption to maintain the suspension state of the powder curing agent in the powder gas conveying pipe to prevent it from settling or clogging. The main gas pipeline focuses on strong conveying, and the auxiliary gas pipeline focuses on suspension maintenance, avoiding possible pressure interference caused by time-sharing reuse of a single gas pipeline, so that the main gas source pressure is restored more fully and the auxiliary gas line suspension control is more precise. The auxiliary gas pipe only needs to provide the minimum gas volume to maintain suspension, which is more energy-efficient than the single gas pipe mode; at the same time, the independent auxiliary gas line can respond to the risk of settlement more promptly, further reducing the probability of pipeline blockage.

[0014] Preferably, the quantitative unloading unit includes a charging valve, a quantitative chamber and an injection valve connected in sequence, the inlet of the charging valve is connected to the guide pipe, and the outlet of the injection valve is connected to the gas-solid mixing chamber; the control unit is configured to coordinate the opening and closing actions of the charging valve and the injection valve to achieve pulsed quantitative unloading; the control unit is configured to periodically execute a quantitative unloading operation cycle including the following steps; during charging: the injection valve of the quantitative unloading unit is controlled to be in a closed state, and the charging valve is opened at the same time, so that under the preset working pressure of the feeding tank body, the powder curing agent is filled from the feeding tank body through the guide pipe into the quantitative chamber with a predetermined volume until the predetermined injection condition is reached; during injection: after the filling of the quantitative chamber is completed, the charging valve is controlled to be closed, and the injection valve is intermittently opened and closed once or multiple times according to the preset opening frequency and / or single opening time parameters, so that the powder curing agent of the predetermined volume stored in the quantitative chamber is pulsed and injected into the gas-solid mixing chamber of the pneumatic conveying unit under the internal pressure of the quantitative chamber. Through the intermittent opening and closing of the injection valve, the powder in the quantitative cavity is pulsed into the gas-solid mixing chamber, matching the pulse gas source of the subsequent pneumatic conveying to ensure that the powder and gas are evenly mixed and the conveying efficiency is improved.

[0015] Preferably, the longitudinal profile of the flow guide tube in a vertical plane containing the central axis of the metering chamber includes, but is not limited to, a right-angled profile, a bullhorn profile, or any other smoothly transitioned curved shape; the internal flow channel of the metering chamber is a variable diameter structure, and the variable diameter structure includes, from inlet to outlet, an inlet diameter expansion section connected to the outlet of the charging valve, an intermediate constant diameter metering section, and an outlet diameter reduction section connected to the inlet of the injection valve. The smooth profile of the flow guide tube reduces the flow resistance of the powder and avoids accumulation; the inlet diameter expansion section of the metering chamber facilitates rapid filling, the intermediate constant diameter section ensures accurate metering volume, and the outlet diameter reduction section enhances injection kinetic energy, reduces residue, and further improves quantitative accuracy and material discharge smoothness.

[0016] Preferably, the feeding unit further comprises a supporting frame, a connecting flange and a feeding tank exhaust pipe; the feeding tank body is arranged on the supporting frame, the bottom of the feeding tank body is connected to the guide pipe through a connecting flange, and a vibrator is provided at the bottom of the feeding tank body; the feeding tank exhaust pipe is connected to the top of the feeding tank body; the control unit comprises a sensor group, a valve group and a central control cabinet; the sensor group comprises a weighing sensor for monitoring the weight of the powder curing agent in the feeding tank body and a feeding tank pressure gauge for monitoring the pressure in the tank, the weight of the feeding tank body is borne by at least three weighing sensors, each of the weighing sensors The feed tank is fixed to the support frame, with the feed tank body vertically pressed against the load cell. The feed tank pressure gauge is mounted on the feed tank body. The valve assembly includes a feed valve, a feed tank pressurization valve, a feed tank exhaust valve, and a main air circuit switch valve. The feed valve is mounted on the feed tank body and is used to replenish the powder curing agent. The feed tank pressurization valve is mounted on the feed tank inlet pipe, the feed tank exhaust valve is mounted on the feed tank exhaust pipe, and the main air circuit switch valve is mounted on the output air circuit. The central control cabinet is mounted on the support frame and is electrically connected to the vibrator, valve assembly, sensor assembly, and quantitative feeding unit. The vibrator can eliminate "arching" or poor flow of powder (especially for powders prone to agglomeration) to ensure sufficient filling of the quantitative chamber. The load cell monitors the powder remaining in real time, the pressure gauge controls the feed tank pressure, and the central control cabinet coordinates the actions of various components, improving the system's automation level, reducing manual intervention, and ensuring operational stability.

[0017] Preferably, the storage unit is connected to the feed tank body and is used to refill the feed tank body; the storage unit includes a storage tank and a feeding mechanism for transferring powdered curing agent from the storage tank to the feed tank body; the feeding mechanism includes a feeding cage corresponding to the storage tank and a cage motor driving the feeding cage; a tank discharge valve is provided at the bottom of the storage tank; the control unit automatically controls the start and stop of the feeding mechanism and the opening and closing of the tank discharge valve based on signals from a weighing sensor on the feed tank body, thereby achieving on-demand automatic refilling of the feed tank body. When the powder remaining in the feed tank is insufficient, the refill process is automatically triggered to avoid construction stagnation due to material shortage and improve construction efficiency.

[0018] Preferably, the central control cabinet of the control unit is configured to dynamically control the opening and closing of the feed tank pressurizing valve and the feed tank exhaust valve based on the pressure data fed back by the feed tank pressure gauge, so as to accurately maintain the pressure in the feed tank body within a preset working pressure range; this stable upstream pressure is intended to ensure that when the charging valve is opened according to a preset program to charge the quantitative chamber, the quantitative chamber can obtain a consistent amount of powder curing agent filling and the same initial internal pressure each time, thereby ensuring that in each subsequent injection cycle in which the injection valve is opened according to a preset program, the amount of powder curing agent ejected from the quantitative chamber is highly consistent, thereby achieving overall quantitative unloading; the central control cabinet of the control unit is further configured to, during or before the process of filling the quantitative chamber through the charging valve, start the vibrator on the outer wall of the feed tank body in a timely manner according to preset conditions or real-time monitored powder curing agent flow status, so as to assist the powder curing agent in overcoming potential arching or poor flow, and ensure that it flows smoothly and quickly into the quantitative chamber. Stable tank pressure ensures consistent powder delivery to the metering chamber each time (a core requirement for volumetric metering), preventing deviations in discharge volume due to tank pressure fluctuations (addressing the prior art issue of unstable tank pressure disrupting airlock discharge accuracy). Stable initial pressure in the metering chamber ensures consistent powder delivery during the injection phase, preventing weak injection.

[0019] Preferably, the central axis of the gas pipe intersects with the central axis of the gas-solid mixing chamber, and the angle is preferably less than 60°; the gas-solid mixing chamber includes a variable diameter structure composed of a contraction section at the inlet end, a mixing section in the middle, and a divergent section at the outlet end, which are connected in sequence, wherein the cross section of the contraction section is gradually contracting, the mixing section is a straight pipe section with a constant cross section, and the cross section of the divergent section is gradually expanding; all gas pipes are symmetrically distributed along the circumference of the gas-solid mixing chamber, or are distributed at intervals along the axial direction of the gas-solid mixing chamber. The angle design of the gas pipe and the variable diameter structure of the mixing chamber (the contraction section accelerates the airflow, the mixing section fully mixes, and the divergent section transports stably) make the powder and gas mix more evenly and reduce the transportation resistance. The symmetrical / interval distribution of the gas pipes ensures that the airflow is evenly distributed around the mixing chamber, prevents local accumulation of powder due to airflow deviation, and further reduces the risk of pipe blockage.

[0020] A construction method for a powder injection pile backstage based on the above-mentioned air source reuse air-lock pulse feeding comprises the following steps:

[0021] S1. Operation parameter setting: Set the background operation parameters on the central control cabinet. The parameters include at least: the filling duration of the working cycle of the quantitative unloading unit, the opening and closing frequency and / or single opening duration of the injection valve, the preset working pressure of the feeding tank body, the pressure threshold and time period of the switching conditions between the main gas line conveying stage and the auxiliary gas line conveying stage, the weight of the feeding tank body to be loaded, the opening and closing cycle of the gas pipe switch valve, the minimum safety pressure threshold in the feeding tank body to be met, and the powder curing agent remaining threshold for starting automatic feeding to the feeding tank body;

[0022] S2. Initial loading of the feed tank: Close the feed tank pressurizing valve, open the feed tank exhaust valve, wait until the internal pressure on the feed tank pressure gauge shows zero, open the feed valve on the top of the feed tank body, and simultaneously start the cage motor connected to the corresponding storage tank in the storage unit and open the storage tank discharge valve at the bottom of the storage tank to transfer the powder curing agent from the storage tank to the feed tank body; when the weight monitored by the weighing sensor on the feed tank assembly reaches the set weight to be loaded, close the storage tank discharge valve, stop the cage motor, and close the feed valve and the feed tank exhaust valve in sequence;

[0023] S3. System startup, pre-pressurization and standby: Start the air supply unit, open the feed tank pressure valve, pressurize the feed tank body to the preset working pressure, and the central control cabinet dynamically maintains the pressure based on the feedback from the feed tank pressure gauge; after receiving the ready signal sent by the front-end pile driver, the central control cabinet enters the operation standby state, opens the main air circuit switch valve, and starts the air pipe switch valve to intermittently open and close according to the preset cycle, and the back-end enters the spraying standby state;

[0024] S4. Execute phased coordinated air supply: After receiving the command to start spraying operation from the front pile driver, the control unit uses the control logic set in the central control cabinet and real-time sensor feedback to autonomously switch between the main air path delivery phase and the auxiliary air path phase;

[0025] S5. Execute the quantitative feeding cycle: After receiving the spraying operation instruction from the front pile driver, the central control cabinet of the control unit drives the charging valve and the injection valve of the quantitative feeding unit to open and close periodically and in a coordinated manner, repeating the quantitative feeding operation cycle to achieve continuous and quantitative powder supply to the front pile driver. The feeding operation includes the following steps:

[0026] (a) Charging: First close the injection valve, then open the charging valve, and under the preset working pressure of the feed tank body,

[0027] The powder curing agent is fed from the feeding tank body through the guide pipe into the quantitative chamber according to the set filling time;

[0028] (b) Injection: The charging valve is then closed, and the injection valve is controlled to open and close intermittently or open once according to a preset opening and closing frequency and / or single opening duration. Under the action of the internal pressure of the quantitative chamber, the batch of powder curing agent in the quantitative chamber is injected into the gas-solid mixing chamber of the pneumatic conveying unit to be fully mixed with the compressed air from the air pipe before being conveyed;

[0029] S6. Refilling the feed tank on demand: During the quantitative unloading operation, the weight of the powder curing agent in the feed tank body is continuously monitored; when the weighing sensor detects that the powder curing agent remaining amount is lower than the powder curing agent remaining amount threshold set in step S1, the central control cabinet sends a request to the front-end pile driver to suspend drilling and maintain idling; after the front-end pile driver responds and enters the idling state, the central control cabinet suspends the quantitative unloading cycle and then executes the loading procedure to the feed tank body in step S2; after the loading is completed, the back-end returns to the standby state and notifies the front-end pile driver that it can resume operation;

[0030] S7, end of single pile operation: When receiving the operation completion instruction from the front-end pile driver, the central control cabinet stops the quantitative material discharge cycle, closes all valves, and completes the operation; when waiting for the front-end pile driver to move and issue a new pile operation instruction, the operation process of steps S1 to S6 is repeated until the construction of all predetermined pile positions is completed.

[0031] By adopting a single gas supply source configuration and innovatively designing a system architecture for gas source reuse, this invention combines a phased coordinated gas supply intelligent control strategy. Compared with the air-lock unloading system in another patent filed by the applicant on the same application date, this invention inherits its advantages and aims to achieve one or more of the following beneficial effects:

[0032] (1) Ensure stable delivery and achieve efficient management of a single gas source: The most significant advantage of this invention is that, by using the feed tank as an auxiliary gas source during the interval of the main delivery pulse, a precisely controlled auxiliary air flow is added to the pipeline, maintaining the suspended flow of the powder in the pipe with minimal energy consumption, fundamentally solving the sedimentation and pipe blockage problem of single-gas source pulse delivery. At the same time, through the intelligent switching of the main and auxiliary gas lines, the main gas source is completely isolated from the gas-consuming delivery pipeline, enabling it to quickly and efficiently restore pressure, reserve sufficient energy for the next main delivery pulse, and perfectly solve the power distribution contradiction of a single gas source.

[0033] (2) Simplify the system and reduce costs, achieving both high reliability and economy: Compared with the dual-gas source system that requires two sets of independent gas supply modules for risk-free operation, the present invention, with its innovative single-gas source gas source reuse design, achieves a delivery reliability comparable to or even exceeding that of the dual-gas source system at the lowest hardware cost, significantly simplifies the equipment structure, reduces initial investment and subsequent maintenance costs, and has significant economic benefits.

[0034] (3) Guaranteed High-Precision Quantitative Dispensing: This invention fully inherits the advantages of the air-lock quantitative dispensing unit described in another patent filed by the applicant on the same application date. By batch-based filling and draining of the quantitative chamber, highly consistent quantitative dispensing is achieved between batches. Furthermore, due to more complete recovery of the main air source and more stable pressure in the feed tank, the present invention further ensures dispensing accuracy.

[0035] (4) Improved Automation and Intelligence: This invention elevates control logic from simple valve timing to multi-stage intelligent switching based on multi-dimensional feedback from system pressure, valve status, and other information. The entire coordinated gas supply process is autonomously completed by a central control cabinet, which not only improves operational reliability but also enables the system to adaptively adjust according to actual operating conditions, significantly enhancing the intelligent level of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a front view of the overall structure of the first embodiment of the present invention;

[0037] Figure 2 This is a rear view of the overall structure of embodiment 1 of the present invention;

[0038] Figure 3 This is a schematic structural diagram of an air supply unit according to a first embodiment of the present invention;

[0039] Figure 4 This is a schematic structural diagram of a material storage unit according to a first embodiment of the present invention;

[0040] Figure 5 This is a pneumatic conveying circuit diagram of Example 1 of the present invention;

[0041] Figure 6 This is a schematic diagram of the structure of the quantitative feeding unit, mixing chamber and gas pipe according to the first embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the overall structure of the feeding unit according to the first embodiment of the present invention;

[0043] Figure 8 This is another view of the overall structure of the feeding unit according to the first embodiment of the present invention;

[0044] Figure 9 This is a top view of the entire structure of the feeding unit according to the first embodiment of the present invention;

[0045] Figure 10 This is a schematic structural diagram of a quantitative blanking unit according to a first embodiment of the present invention;

[0046] Figure 11 Schematic diagram of the construction method of embodiment 1 and embodiment 2 of the present invention;

[0047] Figure 12This is a schematic diagram of the collaborative work between the first and second embodiments of the present invention and the front desk;

[0048] Figure 13 This is a schematic structural diagram of a quantitative blanking unit according to a third embodiment of the present invention;

[0049] Figure 14 This is a schematic structural diagram of a powder gas injection assembly according to a fourth embodiment of the present invention;

[0050] Figure 15 for Figure 14 Enlarged diagram of the circle in the middle

[0051] Figure 16 This is a schematic diagram of the construction method of embodiment 5 of the present invention. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] Example 1

[0054] like Figures 1 to 12 As shown, the present invention provides a powder injection pile backstage with air source reuse and air-lock pulse feeding, including an air supply unit 1, a feeding unit 2, a quantitative unloading unit 6, a pneumatic conveying unit 3, a storage unit 5 and a control unit 4 for controlling the coordinated operation of each unit; the air supply unit 1 includes a set of air supply modules consisting of an air compressor 11, an air storage tank 12 and a cold dryer 13. The air inlet end of the cold dryer 13 is provided with an air inlet filter 141, and the air outlet end is provided with two air outlet filters 142 for removing moisture and impurities in the compressed air. The output air path 304 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 feeding unit 2. The feeding unit 2 includes a feeding tank body 210 and a guide pipe 216 connected to the discharge port of the feeding tank body 210. Specifically, as shown in FIG. Figure 12As shown, the longitudinal profile of the flow guide tube 216 in this embodiment, within a vertical plane containing its own central axis, is a bullhorn profile. This reduces the flow resistance of the powder, avoids powder blockage or uneven flow rate caused by sudden changes in the flow path, and ensures smooth transportation of the powder from the feed tank to the metering chamber 62. The longitudinal profile can also be a right-angle profile or any other smoothly transitioned curved shape. The pneumatic conveying unit 3 includes at least one air delivery pipe 303 and a powder-gas delivery pipe 31; this embodiment uses two air delivery pipes 303, namely a first air delivery pipe 303.a and a second air delivery pipe 303.b. The inlet ends of the first and second gas pipes 303.a and 303.b converge and connect to the output gas path 304 of the gas supply unit 1. A master gas path on / off valve 418 is installed on this output gas path 304. The outlet ends of the first and second gas pipes 303.a and 303.b converge with the discharge end of the flow guide pipe 216 to form a gas-solid mixing chamber 305. A pressure relief hole is provided in the gas-solid mixing chamber 305 for pressure relief, further controlling the pressure within the pipes. A first gas pipe on / off valve 419.a, controlled by the control unit 4, is installed on the first gas pipe 303.a, and a second gas pipe on / off valve 419.b, controlled by the control unit 4, is installed on the second gas pipe 303.b. A tank air inlet pipe 214 is connected between one of the air pipes 303 (the second air pipe 303.b) and the tank body 210. The air inlet end of the tank air inlet pipe 214 is connected to the second air pipe 303.b, and the air outlet end of the tank air inlet pipe 214 is connected to the top of the tank body 210. A tank pressurizing valve 413 is provided on the tank air inlet pipe 214. The air inlet end of the powder gas conveying pipe 31 is connected to the gas-solid mixing chamber 305, and the air outlet end of the powder gas conveying pipe 31 is connected to the pile driver 7; the quantitative discharging unit 6 includes a charging valve 61, a quantitative chamber 62 and an injection valve 63 connected in sequence, the inlet of the charging valve 61 is connected to the guide pipe 216, and the outlet of the injection valve 63 is connected to the gas-solid mixing chamber 305; the control unit 4 is configured to coordinate the opening and closing actions of the charging valve 61 and the injection valve 63 to achieve pulsed quantitative discharging.

[0055] Control method for powder injection pile backstage with air source reuse and air-lock pulse feeding: The control unit 4 is further configured to execute a phased coordinated air supply strategy, which includes a main air path delivery phase and an auxiliary air path delivery phase, and switches between the two phases periodically or according to the system pressure state:

[0056] S1. During the main gas path delivery phase: the control unit 4 controls the main gas path switch valve 418 to be in the open state, and intermittently opens and closes the first gas pipeline switch valve 419.a to provide a pulsed main delivery gas source for high-speed delivery of the powdered curing agent ejected from the quantitative unloading unit 6;

[0057] S2. In the auxiliary gas line delivery stage: when all the following preset conditions are met: ① the first gas pipe switch valve 419.a is in the closed state; ② the charging valve 61 of the quantitative unloading unit 6 is in the closed state; ③ the pressure in the delivery tank body 210 is monitored to be higher than a preset safety threshold.

[0058] S2, the control unit 4 performs a set of linkage operations, including: controlling the main gas circuit switch valve 418 to close to isolate the gas supply unit 1 from the delivery pipeline, so that it can efficiently restore the pressure in the gas storage tank 12; and at the same time controlling the delivery tank pressurizing valve 413 to open and the second gas delivery pipe switch valve 419.b to open and close in a pulsed manner to draw pressurized gas from the delivery tank body 210 as an auxiliary gas source to maintain the suspended state of the powder curing agent in the powder gas delivery pipe 31 to prevent it from settling or clogging.

[0059] Specifically, pulsed air supply is a common strategy for balancing conveying energy consumption and air source pressure recovery. However, during the "off" intervals of the main conveying airflow, this strategy can cause powder in long pipelines to lose conveying kinetic energy, leading to sedimentation and accumulation. This is particularly true in vertical or inclined ascending sections, where a high-density "dense phase plug" can easily form. This directly results in the system having to overcome a starting pressure far higher than that required under normal conveying conditions to propel these stationary plugs when the next pulsed airflow is activated. This transient high-pressure demand not only places a significant load on the single air source but can also easily lead to complete pipeline blockage due to insufficient thrust, a core difficulty of this technical approach. To resolve this contradiction, the aforementioned phased, coordinated air supply strategy utilizes an auxiliary air path (second air pipeline 303.b) during the "auxiliary air path conveying phase" when the main airflow is off, using the feed tank body 210 itself as a pressure buffer to supplement a precisely controlled, low-flow "suspended" airflow into the powder gas conveying pipe 31. The purpose of this auxiliary airflow is not to transport the powder over long distances, but to maintain the fluidization or suspension of the powder within the pipeline with minimal air consumption, fundamentally eliminating the formation of dense phase plugs. Thus, each time the main conveying airflow is activated, it encounters a low-resistance flow pattern that is easy to accelerate, ensuring the continuity and high reliability of the entire conveying process.

[0060] Specifically, such as Figures 7-9As shown, the feeding unit 2 also includes a support frame 212, a connecting flange 211, a feed tank exhaust pipe 215, a ladder, and a guide pipe dredging hole 218. The feed tank body 210 is a pressure vessel structure with a tapered discharge structure at its lower end. The feed tank body 210 is mounted on the support frame 212. The bottom of the feed tank body 210 is connected to the guide pipe 216 via the connecting flange 211. The guide pipe 216 is used to transport the powder to the gas-solid mixing chamber 305. The guide pipe dredging hole 218 is connected to the guide pipe 216 to achieve a dredging effect. The outer wall of the feed tank body 210 is provided with multiple vibrators 213, which ensure uniform powder transportation. The weight of the tank body 210 is supported by three load cells 401. The lower portions of these load cells are fixed to the support frame 212, and their upper portions are connected to the outer wall of the tank body 210. This connection allows the tank body 210 to have a certain degree of lateral freedom of movement while transmitting vertical loads, ensuring accurate weighing measurements. A feed valve 411 for replenishing powdered curing agent is located at the top of the tank body 210. A tank exhaust pipe 215, equipped with a tank exhaust valve 414, is also located at the top of the tank body 210. A tank safety valve 415 is also located at the top of the tank body 210 to ensure safe air pressure inside the tank. A ladder is located on one side of the support frame 212 for easy access and maintenance. The vibrator 213 , the weighing sensor 401 , the feed valve 411 , the feed tank pressurizing valve 413 , the feed tank exhaust valve 414 and the feed tank safety valve 415 are all electrically connected to the central control cabinet 42 of the control unit 4 .

[0061] Specifically, such as Figure 3 and 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 feeding tank body 210, a feeding tank pressure gauge 403 for monitoring the pressure in the feeding tank body 210, a gas tank pressure gauge 404 for the gas tank 12, and a total gas pipe pressure gauge 402 for monitoring the delivery pipeline; each weighing sensor 401 is fixed to the support frame 212, and the feeding tank body 210 is vertically pressed on the weighing sensor 401, and the feeding tank pressure gauge 403 is set on the feeding tank body 210; the gas tank pressure gauge 404 is set on the top of the gas tank 12, and the total gas pipe pressure gauge 402 is set on the output gas path 304 of the gas supply unit 1 On the top, the valve group includes a feed tank pressurizing valve 413 and a feed tank exhaust valve 414 for regulating the pressure of the feed tank body 210, a feed valve 411, a storage tank discharge valve 416, a main gas circuit switch valve 418, and a gas pipe switch valve 419; the feed valve 411 is arranged at the top center of the feed tank body 210, the feed tank pressurizing valve 413 is arranged on the feed tank air inlet pipe 214, the feed tank exhaust valve 414 is arranged on the feed tank exhaust pipe 215, the storage tank discharge valve 416 is arranged at the bottom of the storage tank 50 of the storage unit 5, the main gas circuit switch valve 418 is arranged on the output gas circuit 304 of the gas supply unit 1, and a main gas pipe manual valve 417 is also arranged on the output gas circuit 304, and the gas pipe switch valve 419 is arranged on the gas pipe 303.

[0062] The central control cabinet 42 is electrically connected to the valve group, the sensor group, and the charging valve 61 and the injection valve 63 of the quantitative unloading unit 6; the central control cabinet 42 is configured to periodically execute a quantitative unloading operation cycle comprising the following steps:

[0063] S8: Filling: Control the injection valve 63 of the quantitative feeding unit 6 to be in a closed state, and open the filling valve 61 at the same time, so that under the preset working pressure of the feeding tank body 210, the powder curing agent is discharged from the feeding tank body 210 through the guide pipe.

[0064] The tube 216 is filled into the metering chamber 62 having a determined volume until the predetermined injection condition is reached;

[0065] S9: Injection: After the metering chamber 62 is filled, the charging valve 61 is controlled to close, and the injection valve 63 is intermittently opened and closed once or multiple times according to the preset opening frequency and / or single opening time parameters, so that the predetermined volume of powder curing agent stored in the metering chamber 62 is pulsed and injected into the gas-solid mixing chamber 305 of the pneumatic conveying unit 3 under the action of the internal pressure of the metering chamber 62.

[0066] Specifically, such as Figure 5 As shown, the central axes of the two gas delivery pipes 303 intersect with the central axis of the gas-solid mixing chamber 305, and the included angle is less than 60°, preferably 30°.

[0067] Specifically, such as Figure 10 As shown, the internal flow channel of the quantitative cavity 62 of the quantitative feeding unit 6 is constructed as a variable diameter structure connected in sequence, which includes an inlet expansion section connected to the outlet of the charging 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.

[0068] Specifically, the inlet expansion section helps reduce the flow rate of the powder curing agent entering from the flow guide tube 216, reducing impact and disturbance, allowing the powder to more smoothly and densely fill the entire metering chamber 62, improving the accuracy and repeatability of single-shot metering. The intermediate constant-diameter metering section provides a precise volumetric reference, ensuring the geometric consistency of the powder curing agent dosage for each batch. At the moment the injection valve 63 opens, the outlet reduction section accelerates and focuses the powder curing agent, which is under high pressure and about to be discharged from the metering chamber 62, thereby forming a high-speed material flow with more concentrated energy and better directionality. This Venturi effect, or a similar throat effect, helps increase the injection velocity and initial kinetic energy of the powder, enhance its penetration and initial dispersion performance in the downstream gas-solid mixing chamber 305, and may also improve the shutoff performance of the injection valve 63, reducing dripping or residue of the powder curing agent. Compared to a simple constant-diameter tube metering chamber, this "expansion-constant-reduction" structure optimizes the internal flow field and is more conducive to achieving fast, accurate, and efficient pulsed quantitative feeding.

[0069] Specifically, such as Figure 7 As shown, the central control cabinet 42 of the control unit 4 is configured to dynamically control the opening and closing of the feed tank pressurizing valve 413 and the feed tank exhaust valve 414 based on the pressure data fed back by the feed tank pressure gauge 403, so as to accurately maintain the pressure in the feed tank body 210 within the preset working pressure range; this stable upstream pressure is intended to ensure that when the charging valve 61 is opened according to the preset program to charge the metering chamber 62, the metering chamber 62 can obtain a consistent filling amount of powder curing agent and the same initial internal pressure each time, thereby ensuring that in each injection cycle in which the subsequent injection valve 63 is opened according to the preset program, the amount of powder curing agent ejected from the metering chamber 62 is highly consistent, thereby achieving overall quantitative discharging.

[0070] Specifically, the central control cabinet 42 of the control unit 4 is further configured to start the vibrator 213 on the outer wall of the feed tank body 210 in a timely manner according to preset conditions or real-time monitoring of the flow state of the powder curing agent during or before the charging process into the quantitative chamber 62 through the charging valve 61, so as to assist the powder curing agent in overcoming potential arching or poor flow, and ensure that it flows smoothly and quickly into the quantitative chamber 62.

[0071] Specifically, such as Figure 4As shown, the storage unit 5 includes a storage tank 50 and a feeding mechanism for transporting the powder curing agent from the storage tank 50 to the feed tank body 210. The feeding mechanism includes a feeding cage 51 corresponding to the storage tank 50 and a cage motor 52 for driving the feeding cage 51, as well as a wire rope 53 for fixing the cage motor 52. A storage tank discharge valve 416 is provided at the bottom of the storage tank 50; 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 feed tank body 210, so as to realize automatic replenishment of materials to the feed tank body 210 on demand.

[0072] In this embodiment, combined with Figure 11 , also discloses a construction method for the powder injection pile backstage with the above-mentioned air source reuse air-lock pulse feeding, which includes the following standard steps:

[0073] S1: Setting operating parameters: Setting background operating parameters on the central control cabinet 42, the parameters at least include: the working cycle of the quantitative unloading 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 feeding tank body 210, the switching conditions between the main gas line conveying stage and the auxiliary gas line conveying stage such as the pressure threshold and time period of the gas storage tank 12, the weight of the material to be loaded in the feeding tank body 210, the opening and closing cycle of the first gas line switch valve 419.a, the minimum safety pressure threshold in the feeding tank body 210 required to open the second gas line switch valve 419.b, and the powder curing agent remaining threshold for starting automatic feeding to the feeding tank body 210;

[0074] S2: Initial loading of the feed tank: Close the feed tank pressurizing valve 413, open the feed tank exhaust valve 414, wait until the feed tank pressure gauge 403 shows that its internal pressure is zero, open the feed valve 411 on the top of the feed tank body 210, and simultaneously start the cage 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 transfer the powdered curing agent from the storage tank 50 to the feed tank body 210; when the weight monitored by the weighing sensor 401 on the feed tank assembly 21 reaches the set weight to be loaded, close the storage tank discharge valve 416, stop the cage motor 52, and close the feed valve 411 and the feed tank exhaust valve 414 in sequence;

[0075] S3: System startup, pre-pressurization and standby: Start the air supply unit 1, open the feed tank pressurization valve 413, pressurize the feed tank body 210 to the preset working pressure, and the central control cabinet 42 dynamically maintains the pressure based on the feedback from the feed tank pressure gauge 403; after receiving the ready signal sent by the front-end pile driver 7, the central control cabinet 42 enters the operation standby state, opens the main air circuit switch valve 418, and starts the air pipe switch valve 419 by the central control cabinet 42 to intermittently open and close according to the preset cycle, and the back-end enters the spraying standby state;

[0076] S4: Execute phased coordinated air supply: After receiving the command to start spraying operation from the front pile driver, the central control cabinet 42 automatically switches between the "main air line delivery phase" and the "auxiliary air line delivery phase" according to the preset control logic and real-time sensor feedback to achieve continuous quantitative supply. The specific phase operations are as follows:

[0077] (a) During the main gas delivery phase: the control unit controls the main gas circuit switch valve 418 to be in the open state, and intermittently opens and closes the first gas pipeline switch valve 419.a to provide a pulsed main gas source.

[0078] Used for high-speed transportation of powder curing agent ejected from the quantitative feeding unit;

[0079] (b) During the auxiliary gas line delivery stage: when all the following preset conditions are met: ① the first gas pipe switch valve 419.a is in the closed state; ② the charging valve 61 of the quantitative unloading unit is in the closed state; ③ the pressure in the delivery tank body is monitored to be higher than a preset safety threshold.

[0080] The control unit performs a set of linked operations, including: controlling the main gas circuit switch valve 418 to close, so as to isolate the gas supply unit 1 from the delivery pipeline, thereby enabling it to efficiently restore the pressure in the gas storage tank;

[0081] At the same time, the feed tank pressurizing valve 413 is controlled to open and the second gas pipe switch valve 419.b is pulsed to open and close, so as to draw pressurized gas from the feed tank body 210 as an auxiliary gas source to maintain the suspended state of the powder curing agent in the powder gas delivery pipe 31 to prevent it from settling or clogging.

[0082] S5: Execute the quantitative feeding cycle: After receiving the start spraying operation instruction from the front-end pile driver 7, the central control cabinet 42 of the control unit 4 drives the charging valve 61 and the injection valve 63 of the quantitative feeding unit 6 to open and close periodically and in a coordinated manner, repeating the quantitative feeding operation cycle to achieve continuous and quantitative powder supply to the front-end pile driver 7. The feeding operation includes the following steps:

[0083] (a) Charging: First, close the injection valve 63, then open the charging valve 61. Under the preset working pressure of the feeding tank body 210, the powdered curing agent is charged from the feeding tank body 210 through the guide tube 216 into the metering chamber 62 according to the set charging time;

[0084] (b) Injection: The charging valve 61 is then closed, and the injection valve 63 is controlled to be intermittently opened and closed or opened only once according to a preset opening and closing frequency and / or a single opening duration. Under the action of the internal pressure of the quantitative chamber 62, the batch of powdered curing agent in the quantitative chamber 62 is injected into the gas-solid mixing chamber 305 of the pneumatic conveying unit 3 to be fully mixed with the compressed air from the air delivery pipe 403 before being conveyed;

[0085] S6: Refilling the feed tank on demand: During the quantitative unloading operation, the weight of the powder curing agent in the feed tank body 210 is continuously monitored; when the weighing sensor 401 detects that the remaining powder curing agent is lower than the powder curing agent remaining threshold value set in step S1, the central control cabinet 42 sends a request to the front-end pile driver 7 to suspend drilling and maintain idling; after the front-end pile driver 7 responds and enters the idling state, the central control cabinet 42 suspends the quantitative unloading cycle and then executes the loading procedure to the feed tank body 210 in step S2; after the loading is completed, the back-end returns to the standby state and notifies the front-end pile driver 7 that it can resume operation;

[0086] S7: Single pile operation ends: When receiving the operation completion instruction from the front-end pile driver 7, the central control cabinet 42 stops the quantitative material discharge cycle, closes all valves, and completes the operation; when waiting for the front-end pile driver 7 to shift and issue a new pile operation instruction, the operation process of steps S1 to S6 is repeated until the construction of all predetermined pile positions is completed.

[0087] The advantages of this embodiment include: first, improved precision: air-locked quantitative unloading + pressure closed-loop control solves the unloading deviation problem of traditional mechanical devices; second, reliable anti-blocking: time-sharing gas supply between the main and auxiliary air circuits eliminates the risk of pipe blockage during intermittent periods, and is suitable for long-distance / deep transportation; third, cost-effective: single air source architecture + reuse of auxiliary air source in the feed tank avoids the cost of adding an independent air supply unit; fourth, high automation: sensor monitoring + intelligent control realizes automation of the entire process of unloading and replenishing, thereby improving construction efficiency.

[0088] Example 2

[0089] like Figure 11 As shown, this embodiment aims to provide a background configuration with better gas-solid mixing effect. Its physical structure is shown in the figure. The pneumatic conveying unit 3 includes a first gas pipe 303.a and a second gas pipe 303.b. Unlike the solution in Example 1, in this embodiment, the first gas pipe 303.a and the second gas pipe 303.b are both used as main gas pipes to provide symmetrical and powerful conveying airflow during the main conveying stage. At the same time, the auxiliary gas circuit shares the physical pipeline with the second gas pipe 303.b and is time-shared and multiplexed by the control unit 4.

[0090] The control unit 4 is configured to execute a phased coordinated gas supply strategy including “symmetrical main delivery” and “single-path auxiliary suspension”:

[0091] (a) Main gas flow phase: Main gas flow on / off valve 418 is kept open. Simultaneously, first gas flow on / off valve 419.a and second gas flow on / off valve 419.b are synchronously and intermittently opened and closed at a preset main flow frequency. The two symmetrical airflows converge within gas-solid mixing chamber 305, forming a stable, uniform flow field.

[0092] (b) Auxiliary air delivery phase: When both on-off valves 419.a and 419.b in the main delivery phase are closed and other pre-set conditions are met (such as the charging valve of the quantitative unloading unit is closed and the feed tank has sufficient pressure), the control unit performs a coordinated operation: First, it closes the main air circuit on-off valve 418, isolating the main air supply unit 1 from the delivery pipeline to quickly restore pressure. Then, it opens the feed tank pressurization valve 413, directing the auxiliary air source from the feed tank into the passage where the second air delivery pipe 303.b is located. At the same time, only the second air delivery pipe on-off valve 419.b is pulsed open and closed at the preset auxiliary air supply frequency, drawing out a small airflow to maintain the critical suspension state of the pipeline powder.

[0093] The advantage of this embodiment is that the gas-solid mixing is more uniform: the use of a dual-path symmetrical main airflow can form a more balanced flow field in the gas-solid mixing chamber 305, which not only provides more abundant power for long-distance and deep-depth transportation, but also allows the powder and gas to be mixed more fully and evenly, reducing the risk of material accumulation on the pipe wall and improving transportation efficiency. By allowing the auxiliary gas line to share pipes and valves with one of the main gas lines, the addition of a third independent auxiliary line is avoided. This "two-in-one" design, while realizing the three logical functions of "dual main lines + auxiliary lines", maintains the simple physical structure of the dual lines, effectively controlling manufacturing costs and system complexity.

[0094] Example 3

[0095] This embodiment (such as Figure 13 The structure of the embodiment shown in FIG1 is similar to that of the embodiment 1, with the key difference being that the dosing chamber 62 of the dosing unit 6 of this embodiment is a straight tube structure with a constant diameter. This is a simpler and more economical air-lock dosing solution that also achieves reliable powder filling and discharge, meeting the basic requirements of dosing.

[0096] The detailed construction method of the construction background of this embodiment is the same or substantially the same as the implementation method described in Example 1, and will not be repeated here.

[0097] Example 4

[0098] Embodiment 4 is another implementation of the present invention. Figure 14 、 15As shown, the general structure of this embodiment is the same as that of the first embodiment. The only difference is that, to achieve a better mixing effect, the gas-solid mixing chamber 305 adopts a variable diameter structure composed of a contracting section 305.a at the inlet end, a constant diameter mixing section 305.b in the middle, and a diverging section 305.c at the outlet end. The contracting section 305.a has a gradually converging 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.

[0099] Specifically, in this variable-diameter structure, the converging section 305.a at the inlet 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 within the airflow. The following equal-diameter mixing section 305.b provides the necessary length and time to allow the powder particles initially dispersed in the converging section 305.a to be further thoroughly mixed under the action of continued turbulence, achieving a high degree of macroscopic and microscopic uniformity. Finally, the diverging section 305.c at the outlet 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 the particle distribution across the cross section, while also facilitating subsequent stable transport within the powder-gas conveying pipe 31. This gas-solid mixing chamber 305, with its unique variable-diameter structure of "converging for accelerated premixing, equal-diameter for thorough mixing, and diverging for stable homogenization," achieves more thorough and uniform mixing of the gas-solid two-phases than a traditional equal-diameter straight pipe through the optimized combination and synergistic effect of each section's functions. This ensures that the powder curing agent delivered to the front-end drilling rig has a high degree of dispersion and concentration consistency in the airflow, which is of great significance to improving the uniformity of spraying, ensuring the quality of the pile body and the stability of the entire construction process.

[0100] The detailed construction method of the construction background of this embodiment is the same or substantially the same as the implementation method described in Example 1, and will not be repeated here.

[0101] Example 5

[0102] like Figure 16 As shown, this embodiment aims to provide a backend configuration with the simplest structure and the highest economic benefits. Its physical structure is shown in the figure. The pneumatic conveying unit 3 consists of only a common gas pipe 303 and a gas pipe switching valve 419 installed thereon. This common gas pipe 303 is innovatively designed to perform two different functions, "primary gas transport" and "auxiliary gas transport," respectively, during different time periods.

[0103] The control unit 4 is configured to implement a phased coordinated gas supply strategy, which includes a primary gas delivery phase and an auxiliary gas delivery phase, both phases sharing a gas delivery pipe 303, and switching between the two phases periodically or according to the system pressure state:

[0104] S1: In the main gas path conveying stage: the control unit 4 controls the gas supply unit 1 to be in the open state, and intermittently opens and closes the gas pipe switch valve 419 according to the preset main conveying frequency to provide a pulsed main conveying gas source for high-speed conveying of the powdered curing agent ejected from the quantitative discharge unit 6;

[0105] S2: In the auxiliary gas line conveying stage: when the gas pipe switch valve 419 is in the closed period of intermittent gas supply in the main gas line conveying stage and it is detected that the pressure in the feed tank body 210 is higher than a preset safety threshold, the control unit 4 performs a set of linkage operations, including: first closing the gas supply unit 1 to isolate the main gas supply unit 1 and restore its pressure; introducing the auxiliary gas source from the feed tank body 210 into the common gas pipe 303 through the feed tank air inlet pipe 214; and again pulse-opening and closing the same gas pipe switch valve 419 according to the preset auxiliary gas supply frequency to deliver the auxiliary gas source to maintain the critical suspension state of the powder.

[0106] The advantage of this embodiment is that compared to any multi-pipeline solution, this embodiment has the most streamlined hardware structure, requiring only one gas pipe and a corresponding switch valve, which greatly reduces manufacturing costs, installation complexity, and potential failure points, making it the most cost-effective solution for achieving the "gas source reuse and anti-blocking" function. It gives the single gas pipe switch valve 419 a dual role: in the main gas line delivery stage, it is a powerful pulse valve; in the auxiliary gas line delivery stage, it is transformed into a sophisticated suspension control valve. This "one valve for multiple uses" design maximizes the utilization rate of individual components and achieves ultimate structural simplicity and economy.

[0107] In summary, the advantages of the present invention include the following:

[0108] First, high-precision quantitative unloading is achieved: an air-locked quantitative unloading unit 6 is used to periodically coordinate the actions of the filling valve 61 and the injection 63 to perform batch filling and discharge of a predetermined volume of quantitative material 62, thereby achieving highly consistent quantitative unloading between batches and overcoming the defects of the traditional unloading method of imprecision and unevenness.

[0109] Second, it ensures stable conveying and completely eliminates pipe blockage risks: The most significant advantage of this invention is that, during the pauses in the main conveying pulse, the conveying tank body 210 serves as an auxiliary air source, providing a continuous, low-flow, pressure-maintaining airflow to the conveying pipeline, effectively maintaining the powder's suspension within the pipeline. This fundamentally solves the problems of powder sedimentation and pipe blockage caused by airflow interruptions in single-source pulsed conveying, significantly improving the system's conveying reliability and continuity under demanding conditions such as long distances and large elevation differences.

[0110] Third, achieving efficient power recovery and distribution: The present invention achieves ultimate management of a single gas source through intelligent switching between the two stages of "main gas line delivery" and "auxiliary gas line delivery." During the auxiliary gas line delivery stage, the main gas source is completely isolated from the gas-consuming delivery pipeline through the main gas line switch valve 418, enabling it to quickly and efficiently restore pressure and reserve sufficient energy for the next main delivery pulse. This strategy of combining "raising troops" and "using troops" perfectly solves the power distribution contradiction under a single gas source configuration.

[0111] Fourth, simplify the system and reduce costs: Compared with the dual-gas source system that must be equipped with two sets of independent gas supply modules to solve the pipe blockage problem, the present invention, with its innovative single-gas source dual-gas path design, achieves a delivery reliability comparable to or even exceeding that of the dual-gas source system at the lowest hardware cost, significantly simplifies the equipment structure, reduces initial investment and subsequent maintenance costs, and has significant economic benefits.

[0112] Fifth, improve the level of automation and intelligence: the present invention changes the control logic from simple valve timing opening and closing to

[0113] This has been elevated to a level of multi-stage intelligent switching based on multi-dimensional information feedback such as system pressure and valve status. The entire coordinated gas supply process is autonomously completed by a central control cabinet, which not only improves operational reliability but also enables the system to adaptively adjust according to actual working conditions, significantly enhancing the level of intelligent construction.

[0114] Although the present invention is disclosed as above, the scope of protection disclosed by the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the scope of protection of the invention.

Claims

1. A powder injection pile backstage with air source reuse and air lock pulse feeding, characterized in that: The invention comprises an air supply unit (1), a feeding unit (2), a quantitative unloading unit (6), a pneumatic conveying unit (3), a material storage unit (5), and a control unit (4) for controlling the coordinated operation of each unit; 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 feeding unit (2); the feeding unit (2) comprises a feeding tank body (210), a guide pipe (216) connected to the discharge port of the feeding tank body (210); the quantitative unloading unit (6) is connected to the outlet of the guide pipe (216); the pneumatic conveying unit (3) comprises at least one air delivery pipe (303), a gas-solid mixing chamber (305), and a powder-gas delivery pipe (31); the air inlet end of each air delivery pipe (303) is connected to the output air path (304) of the air supply unit (1) to realize air source delivery, and the air outlet end of each air delivery pipe (303) is connected to the output air path (304) of the air supply unit (1) to realize air source delivery, and the air outlet end of each air delivery pipe (303) is connected to the output air path (304) of the air supply unit (1) to realize air source delivery. The gas is collected and connected to the discharge end of the quantitative feeding unit (6) to the gas-solid mixing chamber (305); the control unit (4) is configured to coordinate the opening and closing actions of the quantitative feeding unit (6) to achieve pulsed quantitative feeding; the inlet of the powder gas conveying pipe (31) is connected to the outlet of the gas-solid mixing chamber (305); a feeding tank air inlet pipe (214) is connected between one of the air pipes (303) and the feeding tank body (210), and the feeding tank air inlet pipe (214) forms a two-way air path between the two to achieve pressurization of the feeding tank body (210), or reversely convey the high-pressure gas in the feeding tank body (210) to the powder gas conveying pipe (31) via the feeding tank air inlet pipe (214), the air pipe (303) and the gas-solid mixing chamber (305) in sequence; the storage unit (5) is connected to the feeding tank body (210) and is used to replenish the feeding tank body (210).

2. A single gas pipe control method for the powder injection pile backstage based on the gas source reuse air-lock pulse feeding according to claim 1, characterized in that: The output gas path (304) of the gas supply unit (1) is provided with a main gas path switch valve (418); each gas transmission pipe (303) is provided with a gas transmission pipe switch valve (419); when the pneumatic transmission unit (3) is a gas transmission pipe (303), the control unit (4) is further configured to execute a staged coordinated gas supply strategy, which includes a main gas path transmission stage and an auxiliary gas path transmission stage, the two stages share a gas transmission pipe (303), and switch between the two stages periodically or according to the system pressure state: S1: In the main gas path conveying stage: the control unit (4) is controlled to be in an open state, and the gas pipe switch valve (419) is intermittently opened and closed according to a preset main conveying frequency to provide a pulsed main conveying gas source for high-speed conveying of the powdered curing agent ejected from the quantitative feeding unit (6); S2: During the auxiliary gas line conveying stage: when the gas line switch valve (419) is in the closed period of the intermittent gas supply during the main gas line conveying stage and when it is detected that the pressure in the feed tank body (210) is higher than a preset safety threshold, the control unit (4) performs a set of linkage operations, including: first closing the main gas line switch valve (418) to isolate the gas supply unit (1) to restore its pressure; then opening the feed tank pressurizing valve (413) to introduce the high-pressure gas from the feed tank body (210) into the shared gas line (303) through the feed tank air inlet pipe (214); and again pulse-opening and closing the same gas line switch valve (419) at a preset auxiliary gas supply frequency to deliver the auxiliary gas source for maintaining the critical suspension conveying state of the powder.

3. A method for controlling multiple gas pipes in the backstage of a powder injection pile based on the gas source reuse and air-lock pulse feeding method of claim 1, characterized in that: A main gas circuit switch valve (418) is provided on the output gas circuit (304) of the gas supply unit (1); a gas circuit switch valve (419) is provided on each gas transmission pipe (303); when the pneumatic transmission unit (3) comprises two gas transmission pipes (303), they are respectively a first gas transmission pipe (303.a) and a second gas transmission pipe (303.b); the gas transmission pipe switch valves (419) are a first gas transmission pipe switch valve (419.a) provided on the first gas transmission pipe (303.a) and a second gas transmission pipe switch valve (419.b) provided on the second gas transmission pipe (303.b); the control unit (4) is further configured to execute a phased coordinated gas supply strategy, which includes a main gas circuit transmission phase and an auxiliary gas circuit transmission phase, and switches between the two phases periodically or according to the system pressure state: S1: In the main gas path delivery stage: the control unit (4) controls the main gas path switch valve (418) to be in an open state, The first air delivery pipe switch valve (419.a) is intermittently opened and closed to provide a pulsed main delivery air source for high-speed delivery of the powdered curing agent ejected from the quantitative unloading unit (6); S2: During the auxiliary gas line delivery phase: when the first gas line switch valve (419.a) is in a closed state and the pressure in the delivery tank body (210) is detected to be higher than a preset safety threshold, the control unit (4) performs a set of linkage operations, including: closing the main gas line switch valve (418) to isolate the gas supply unit (1) from the delivery pipeline, This enables the pressure in the air supply unit (1) to be efficiently restored; and simultaneously controls the pulsed opening and closing of the second air delivery pipe switch valve (419.b), drawing high-pressure gas from the delivery tank body (210) through the delivery tank air inlet pipe (214) as an auxiliary gas source, and using the minimum energy consumption to maintain the suspended state of the powder curing agent in the powder gas delivery pipe (31) to prevent it from settling or clogging.

4. The powder injection pile backstage with air source reuse and air lock pulse feeding according to claim 1 is characterized in that: The quantitative discharging unit (6) comprises a charging valve (61), a quantitative chamber (62) and an injection valve (63) which are connected in sequence, wherein the inlet of the charging valve (61) is connected to the flow guide pipe (216), and the outlet of the injection valve (63) is connected to the gas-solid mixing chamber (305); the control unit (4) is configured to coordinate the opening and closing actions of the charging valve (61) and the injection valve (63) to achieve pulsed quantitative discharging; the control unit (4) is configured to periodically execute a quantitative discharging operation cycle comprising the following steps: During charging: the injection valve (63) of the quantitative feeding unit (6) is controlled to be in a closed state, and the charging valve (61) is opened at the same time, so that under the action of the preset working pressure of the feeding tank body (210), the powder curing agent is charged from the feeding tank body (210) through the guide pipe (216) into the quantitative cavity (62) with a predetermined volume until a predetermined injection condition is reached; During injection: after the metering chamber (62) is filled with material, the filling valve (61) is controlled to be closed, and the injection valve (63) is intermittently opened and closed once or multiple times according to a preset opening frequency and / or single opening duration parameter, so that the predetermined volume of powder curing agent stored in the metering chamber (62) is pulse-injected into the gas-solid mixing chamber (305) of the pneumatic conveying unit (3) under the action of the internal pressure of the metering chamber (62).

5. The powder injection pile backstage with air source reuse and air lock pulse feeding according to claim 4 is characterized in that: The longitudinal profile of the flow guide tube (216) in the vertical plane containing the central axis of the metering chamber (62) includes but is not limited to a right-angle profile, a bullhorn profile, or any other smoothly transitioned curved shape; the internal flow channel of the metering chamber (62) is a variable diameter structure, and the variable diameter structure includes, from inlet to out, an inlet diameter expansion section connected to the outlet of the charging valve (61), an intermediate constant diameter metering section, and an outlet diameter reduction section connected to the inlet of the injection valve (63).

6. The powder injection pile backstage with air source reuse and air lock pulse feeding according to claim 4 is characterized in that: The feeding unit (2) further comprises a supporting frame (212), a connecting flange (211) and a feeding tank exhaust pipe (215); the feeding tank body (210) is arranged on the supporting frame (212), the bottom of the feeding tank body (210) is connected to the guide pipe (216) via the connecting flange (211), and a vibrator (213) is provided at the bottom of the feeding tank body (210); the feeding tank exhaust pipe (215) is connected to the top of the feeding tank body (210); the control unit (4) comprises a sensor group, a valve group and a central control cabinet (42); the sensor group comprises a weighing sensor (401) for monitoring the weight of the powder curing agent in the feeding tank body (210) and a feeding tank pressure gauge (403) for monitoring the pressure in the tank, the weight of the feeding tank body (210) is borne by at least three weighing sensors (401), each of the weighing sensors (401) is fixed to the supporting frame (212). The feeding tank body (210) is vertically pressed on the weighing sensor (401), and the feeding tank pressure gauge (403) is arranged on the feeding tank body (210); the valve group includes a feeding valve (411), a feeding tank pressurizing valve (413), a feeding tank exhaust valve (414) and a main gas circuit switch valve (418); the feeding valve (411) is arranged on the feeding tank body (210) and is used to replenish the powder curing agent. The feed tank pressurizing valve (413) is arranged on the feed tank air inlet pipe (214), the feed tank exhaust valve (414) is arranged on the feed tank exhaust pipe (215), and the main gas circuit switch valve (418) is arranged on the output gas circuit (304); the central control cabinet (42) is arranged on the support frame (212), and the central control cabinet (42) is electrically connected to the vibrator (213), the valve group, the sensor group and the quantitative feeding unit (6).

7. The powder injection pile backstage with air source reuse and air lock pulse feeding according to claim 6 is characterized in that: The material storage unit (5) is connected to the feeding tank body (210) and is used to feed the feeding tank body (210); the material storage unit (5) includes a storage tank (50) and a feeding mechanism for feeding the powder curing agent from the storage tank (50) to the feeding tank body (210); the feeding mechanism includes a feeding cage (51) corresponding to the storage tank (50) and a cage motor (52) for driving the feeding cage (51); a storage tank discharge valve (416) is provided at the bottom of the storage tank (50); 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 feeding tank body (210), so as to realize automatic feeding of the feeding tank body (210) on demand.

8. The powder injection pile backstage with air source reuse and air lock pulse feeding according to claim 6 is characterized in that: The central control cabinet (42) of the control unit (4) is configured to dynamically control the opening and closing of the feed tank pressurizing valve (413) and the feed tank exhaust valve (414) based on the pressure data fed back by the feed tank pressure gauge (403), so as to accurately maintain the pressure in the feed tank body (210) within a preset working pressure range; this stable upstream pressure is intended to ensure that when the charging valve (61) is opened according to a preset program to charge the quantitative chamber (62), the quantitative chamber (62) can obtain a consistent amount of powder curing agent filling and the same initial internal pressure each time, thereby ensuring that the subsequent injection valve ( 63) In each injection cycle started according to a preset program, the amount of powder curing agent ejected from the quantitative 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 the process of charging the quantitative chamber (62) through the charging valve (61), start the vibrator (213) on the outer wall of the feeding tank body (210) in a timely manner according to the preset conditions or the real-time monitoring of the flow state of the powder curing agent, so as to assist the powder curing agent in overcoming potential arching or poor flow, and ensure that it flows smoothly and quickly into the quantitative chamber (62).

9. The powder injection pile backstage with air source reuse and air-lock pulse feeding according to claim 1 is characterized in that: The central axis of the gas transmission pipe (303) intersects with the central axis of the gas-solid mixing chamber (305), and the angle is preferably less than 60°; the gas-solid mixing chamber (305) includes a variable diameter structure composed of a contraction section (305.a) at the inlet end, a mixing section (305.b) in the middle, and a divergent section (305.c) at the outlet end, which are connected in sequence, wherein the cross section of the contraction section (305.a) is a gradually contracting shape, the mixing section (305.b) is a straight pipe section with a uniform cross section, and the cross section of the divergent section (305.c) is a gradually expanding shape; all gas transmission pipes (303) are symmetrically distributed along the circumference of the gas-solid mixing chamber (305), or are distributed at intervals along the axial direction of the gas-solid mixing chamber (305).

10. A construction method for powder injection pile backstage based on the air source reuse air-lock pulse feeding described in claim 7, characterized in that: The following steps are involved: S1: Setting of operation parameters: Setting of background operation parameters on the central control cabinet (42), the parameters at least including: the working cycle of the quantitative unloading unit (6) (including the charging time of the quantitative chamber (62), the opening and closing frequency and / or the single opening time of the injection valve (63), the preset working pressure of the feeding tank body (210), the switching conditions between the main gas path conveying stage and the auxiliary gas path conveying stage (such as the pressure threshold of the gas storage tank (12), the time period, etc.), the weight of the material to be loaded in the feeding tank body (210), the opening and closing cycle of the gas pipe switch valve (419), the minimum safety pressure threshold in the feeding tank body (210) to be met, and the residual threshold of the powder curing agent for starting the automatic feeding of the feeding tank body (210); S2: Initial loading of the feeding tank: Close the feeding tank pressurizing valve (413), open the feeding tank exhaust valve (414), wait until the feeding tank pressure gauge (403) shows that the internal pressure is zero, open the feeding valve (411) on the top of the feeding tank body (210), At the same time, the cage motor (52) connected to the corresponding storage tank (50) in the storage unit (5) is started and the storage tank discharge valve (416) at the bottom of the storage tank (50) is opened to transport the powder curing agent from the storage tank (50) to the feed tank body (210); when the weight monitored by the weighing sensor (401) on the feed tank assembly (21) reaches the set weight to be loaded, the storage tank discharge valve (416) is closed, the cage motor (52) is stopped, and the feed valve (411) and the feed tank exhaust valve (414) are closed in sequence; S3: System startup, pre-pressurization and standby: Start the air supply unit (1), open the feed tank pressure valve (413), pressurize the feed tank body (210) to a preset working pressure, and the central control cabinet (42) dynamically maintains the pressure according to the feedback of the feed tank pressure gauge (403); after receiving the ready signal sent by the front pile driver (7), the central control cabinet (42) enters the operation standby state, opens the main air circuit switch valve (418), and starts the air pipe switch valve (419) by the central control cabinet (42) to intermittently open and close according to the preset cycle, and the backstage enters the spraying standby state; S4: Execute phased coordinated air supply: After receiving the spraying operation start instruction from the front pile driver (7), the control unit (4) uses the control logic set by the central control cabinet (42) and the real-time sensor feedback to autonomously switch between the main air path delivery phase and the auxiliary air path phase; S5: Execute the quantitative feeding cycle: After receiving the instruction to start the spraying operation from the front pile driver (7), the central control cabinet (42) of the control unit (4) drives the charging valve (61) and the injection valve (63) of the quantitative feeding unit (6) The system is opened and closed periodically and coordinated to repeat the quantitative feeding operation cycle to realize the continuous and quantitative powder supply to the front pile driver (7). The feeding operation includes the following steps: (a) Charging: First, the injection valve (63) is closed, and then the charging valve (61) is opened. Under the preset working pressure of the feeding tank body (210), the powder curing agent is charged from the feeding tank body (210) through the guide pipe (216) into the quantitative chamber (62) according to the set charging time; (b) Injection: The charging valve (61) is then closed, and the injection valve (63) is controlled to be intermittently opened and closed or opened once according to a preset opening and closing frequency and / or a single opening duration, so that the batch of powder curing agent in the quantitative chamber (62) is injected into the gas-solid mixing chamber (305) of the pneumatic conveying unit (3) under the action of the internal pressure of the quantitative chamber (62) to be fully mixed with the compressed air from the air delivery pipe (403) before being conveyed; S6: Refilling the feeding tank as needed: During the operation, when the weighing sensor (401) detects that the remaining material is lower than the threshold, Pause the unloading operation and work in conjunction with the pile driver (7) to automatically execute the loading procedure as described in S2; S7: Single pile operation ends: When receiving the operation completion instruction from the front pile driver (7), the central control cabinet (42) Stop the quantitative material feeding cycle, close all valves, and complete the operation; wait for the front pile driver (7) to shift and issue a new pile operation instruction, and repeat the operation process of steps S1 to S6 until all the predetermined pile positions are completed.

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