Powder spraying pile feeding background equipment capable of stably conveying powder and control method

Abstract

The invention provides powder spraying pile feeding background equipment capable of stably conveying powder and a control method. The powder spraying pile feeding background equipment comprises a tank body, a gas circuit unit, a conveying pipeline, a feeding device, a mixer and a control unit, and an outlet of the tank body is sequentially connected with the feeding device, the mixer and the conveying pipeline; the peripheral wall of the mixer is connected with at least one gas inlet pipe which is distributed along the circumferential direction; the gas circuit unit comprises a main gas supply pipe and at least one gas supply branch, an inlet of the main gas supply pipe is connected with the gas supply unit, an outlet of the main gas supply pipe is connected with the corresponding gas inlet pipes through the gas supply branches, and an outlet of the conveying pipeline is connected with the powder spraying pile drilling machine. According to the powder spraying pile feeding background equipment capable of stably conveying the powder and the control method, the conveying amount of the curing agent powder can be kept stable and uniform and can be adjusted in a large interval, the loss of conveying energy can be greatly reduced through the specially-designed mixer, and the spraying pressure of the curing agent powder at the position of a drill bit nozzle is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of construction machinery and equipment for underground engineering powder jet mixing pile method, in particular to a powder jet pile feeding background equipment for stabilizing powder delivery and a control method. BACKGROUND

[0002] Soft soil foundation is widely distributed in China, especially in the foundation soil of sea, lake and river areas, which has high water content, large void ratio and high compressibility. For such soft soil foundation, a large amount of soft soil foundation engineering treatment is needed for land development. In the past 70 years, the traditional slurry jet mixing pile technology has been frequently used in civil construction engineering to reinforce and treat such soft foundation. However, the use of slurry jet mixing pile construction technology and method to reinforce and treat such soft soil foundation often cannot meet the design purpose.

[0003] Therefore, the dry mixing pile technology has been developed in the Nordic countries, which uses lime or cement dry powder to reinforce saturated soft soil foundation. This technology and method are particularly suitable for foundation soil with high water content, large void ratio and high compressibility. The application of dry mixing pile technology in civil construction engineering can obtain good reinforcement and treatment effect of soft foundation. Although the powder jet pile has the advantages of high strength, convenient construction and low cost, there are some problems to be solved in the powder jet pile process at present: firstly, the delivery amount of the powder jet pile feeding background in construction is unstable, which leads to a large difference in the mixing amount of curing agent at different depths of the pile body, and even causes pile breakage; the curing agent powder is delivered to the drill bit position by pneumatic conveying, and the conveying energy gradually decreases when the conveying distance is too long, which leads to a decrease in the jet pressure at the jet port, uneven distribution of the curing agent powder, and unsatisfactory pile forming quality; the traditional background control adopts manual control, which is frequent and prone to errors. When the powder delivery deviation is more than ±5%, the manual adjustment response delay is 8-10 seconds, which seriously affects the pile quality. SUMMARY

[0004] In order to overcome at least one defect in the above prior art, the present application provides a powder jet pile feeding background equipment for stabilizing powder delivery and a control method. The use of the background equipment can keep the delivery amount of the curing agent powder stable and uniform, and can be adjusted within a large range. The specially designed mixer can greatly reduce the loss of conveying energy and ensure the jet pressure of the curing agent powder at the drill bit jet port position.

[0005] The technical scheme adopted by the present application is to provide a powder jet pile feeding background equipment capable of stably feeding powder, which comprises a tank body, a gas path unit, a conveying pipeline, a feeding device, a mixer and a control unit, the outlet of the tank body is connected with the upper inlet of the feeding device, the outlet of the feeding device is connected with the inlet of the mixer, the outlet of the mixer is connected with the inlet of the conveying pipeline, and at least one air inlet pipe is connected with the peripheral wall of the mixer; the gas path unit comprises a main gas supply pipe and at least one gas supply branch, the inlet of the main gas supply pipe is connected with a gas supply unit, the outlet of the main gas supply pipe is connected with each corresponding air inlet pipe through each gas supply branch, and the outlet of the conveying pipeline is connected with a powder jet pile drilling machine; the solidifying agent powder in the tank body enters the inside of the mixer along the feeding device under the action of internal pressure and enters the conveying pipeline under the action of high-pressure gas injection of the gas supply branches.

[0006] As an improvement, a rotating shaft is arranged along the central axis in the inside of the tank body, helical blades are arranged on the outer part of the middle and lower part of the rotating shaft, a support frame is arranged on the inner wall of the bottom of the tank body, the lower end of the rotating shaft is rotationally connected with the support frame, and a motor for driving the rotating shaft to rotate is connected with the top of the tank body.

[0007] Further, the gas path unit further comprises a tank body booster pipe, one end of the tank body booster pipe is communicated with the main gas supply pipe or the gas supply unit, the other end is communicated to the top of the tank body, and a booster valve is connected with the tank body booster pipe; a feeding valve for opening and closing a feeding port, a safety valve, a pressure gauge and an exhaust valve for opening and closing an exhaust pipe are further arranged on the upper side wall of the tank body, and a feeding switch valve is connected with the outlet end of the feeding device; a gas path valve for controlling the gas flow is connected with the main gas supply pipe. In the above improved structure, the pressure in the tank is increased by the booster, so that the pressure in the tank is always higher than the pressure in the conveying pipeline by a certain value, and the solidifying agent can be fed into the feeding device at a stable speed, thereby ensuring the uniform distribution of the pile body at each position.

[0008] Further improvement, the motor, the gas supply unit, the booster valve, the feeding valve, the exhaust valve, the safety valve, the pressure gauge, the feeding switch valve and the gas path valve are all uniformly and coordinately controlled by the control unit; during the construction process, the feeding switch valve and the gas path valve are regularly opened and closed according to the set frequency. In the above improved structure, the control unit can automatically control the opening and closing state of each switch valve at different time points through the program, thereby reducing manual operation and avoiding subjective reduction of construction quality; the regular opening and closing of the feeding switch valve and the gas path valve according to the set time makes the feeding more uniform, and a large amount of powder is avoided from gathering at the same position in the pipeline; meanwhile, the temporary pressure reduction in the mixer during the process of the feeding switch valve and the gas path valve alternately closing is beneficial to the discharge of the powder.

[0009] Further improved, the upper feeding port of the feeding device is connected with the discharge port of the tank body, the inner cavity of the feeding device is a boot-shaped cavity gradually widened from top to bottom in length direction, and the two side edges of the boot-shaped cavity are inclined and converged from top to bottom towards the side of the mixer, and the bottom of the boot-shaped cavity is connected with a communication pipe which is in communication with the inlet of the mixer. In the improved structure, the feeding device as a whole has a boot-shaped structure, the tank body discharge port is smoothly connected with the feeding device, the angle of the lower part is conducive to the smooth falling of the curing agent powder, and the connection of the bottom of the boot-shaped cavity with the communication pipe increases the transportation section of the curing agent, reduces the compaction of the curing agent at this position, and effectively prevents blockage.

[0010] Further improved, the mixer has a cylindrical structure, the connecting angle between each gas inlet pipe and the mixer is less than 90°, and each gas inlet pipe is inclined towards the side close to the feeding device. In the improved structure, the gas inlet pipe and the mixer are arranged at an acute angle, so that the high-pressure gas entering the mixer can smoothly enter the conveying pipeline, reducing the loss of conveying energy.

[0011] Further improved, each gas inlet pipe is distributed along the circumferential direction of the mixer, and each gas inlet pipe is arranged at the same distance from the front end of the mixer or is arranged at equal distances along the length direction of the mixer. In the improved structure, when multiple gas inlet pipes symmetrically intake at the same position, the gas flow distribution is more uniform, and the flow path of the curing agent powder is not disordered; when multiple gas inlet pipes are arranged at equal distances along the axial direction and uniformly distributed in the circumferential direction, multiple gas flows can more smoothly enter the conveying pipeline, and the energy of the gas-solid mixed flow is gradually enhanced by the arrangement of the distances between the gas inlet pipes, reducing the occurrence of blockage.

[0012] Further improved, the axis direction of each gas inlet pipe passes through the center line of the mixer. In the improved structure, multiple gas inlet pipes are symmetrically arranged, and the resultant force generated by each gas flow after entering the conveying pipeline is maximum, which can ensure the conveying energy.

[0013] Further improved, the axis direction of each gas inlet pipe has the same eccentricity from the center of the mixer. In the above improved structure, multiple gas inlet pipes are eccentrically and symmetrically arranged, the gas flow forms a rotating gas flow in the pipeline after entering the conveying pipeline, and the structure of multiple gas inlet pipes makes the rotating gas flow energy at the mixer larger and the material carrying capacity stronger.

[0014] In addition, the present application also provides a control method of a powder jet pile feeding background equipment for stably conveying powder, characterized in that the method comprises the following specific processes: S1, before starting piling, first through the control unit one key start to fill the curing agent powder, the feeding switch valve at the rear end of the feeding device is closed, the feeding valve and the exhaust valve at the upper part of the tank are opened, the tank pressure valve is closed, and the curing agent is transported to the inside of the tank through the feeding port, and when the weight of the curing agent reaches the set value, the control unit stops feeding and closes the feeding valve and the exhaust valve, and opens the tank pressure valve; S2, after the above action is completed, the control unit automatically controls the gas supply unit to start providing high-pressure gas, the tank is pressurized to the set pressure through the tank pressure pipeline and is adjusted in real time, the main gas path valve is opened, and the gas is supplied to the conveying pipeline through each gas supply branch and reaches a stable conveying state; S3, operate the powder jet pile drill, the drill bit starts to drill downward, the main gas path valve is closed while the feeding switch valve is opened, and the feeding switch valve and the main gas path valve are opened and closed according to the set time during drilling, the feeding amount of the curing agent is controlled by the opening and closing frequency of the feeding switch valve, the curing agent powder is stably conveyed to the conveying pipeline through the tank, the mixer and the feeding device, and a stable solid-gas mixed flow is formed by using multiple air inlet pipes, and the pressure in the tank is adjusted with the drilling depth during drilling to ensure the uniformity of the curing agent injected into each pile body; S4, when the powder jet pile drill drills and sprays powder to the designed elevation, the pile bottom is stirred, the feeding switch valve is closed to stop feeding while the drill is lifted, the gas path valve is reduced in opening and closing amplitude to supply a small amount of gas, the drill is lifted to the ground to stop, and the construction of a single powder jet pile is completed; S5, the powder jet pile drill 3 moves to the next pile position, and the steps S1-S4 are repeated to construct the next pile body.

[0015] Compared with the prior art, the powder jet pile feeding background equipment and the control method for stably conveying powder of the present application have the following beneficial technical effects: 1, the feeding background of the present application can transport the curing agent to the conveying pipeline according to different conveying amounts by changing the pressure difference in the tank and the conveying pipeline; in addition, the feeding switch valve and the gas path valve are opened and closed according to the set frequency, when the feeding switch valve is opened and the gas path valve is closed, the high-pressure gas in the conveying pipeline stops entering the mixer, a period of time of reduced pressure is generated in the mixer, at this time, the curing agent powder can enter the mixer more smoothly, when the feeding switch valve is closed and the gas path valve is opened, the high-pressure gas can take away the powder in the mixer, in this way, only the pressure is stable, the feeding amount is the same each time, the feeding is more uniform, and in this way, the powder in the pipeline is prevented from gathering at the same position, the possibility of pipe blockage is reduced, and the uniformity of the sprayed powder is improved.

[0016] 2. When the tank pressure reaches the limit pressure, the spiral blade can be added to change the rotating speed to further adjust the conveying capacity. The two adjustment methods make the conveying capacity have a large adjustment interval to adapt to different construction parameters; 3. The feeding device connected with the tank discharge port adopts a boot cavity structure connected with a communication pipe joint with a long slot at the bottom, so that the flow area of the solidified agent powder outward conveying is increased, the output is ensured to be smooth, and the blockage at the outlet position of the feeding device is effectively prevented; 4. A plurality of air inlet pipes arranged on the mixer in front of the conveying pipeline adopt equidistant, unequal distance, axial symmetry, eccentric symmetry and other combined arrangement forms, and different inclination angles are adopted, so that the conveying energy provided by the high-pressure gas is effectively utilized, the conveying capacity of the solidified agent powder is improved, and stable gas-solid fluid is formed in the conveying pipeline; 5. The powder spraying pile feeding background equipment in the application is uniformly controlled by a control unit, and the functions such as feeding and feeding in construction are automatically controlled according to the construction sequence, and at the same time, when feeding the conveying pipeline, the automatic conveying capacity adjustment function reduces manual operation, reduces the occurrence of human subjective factor errors, saves labor cost, and improves construction efficiency.

[0017] The above-mentioned multiple improved advantages of the present application will be specifically described in the following specific embodiments, and part of them will become apparent from the description, or be understood by implementing the present application. The purposes and other advantages of the present application can be achieved and obtained by the structures specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a powder spraying pile feeding background equipment structure schematic diagram of the embodiment one of the present application; Figure 2 It is a powder spraying pile feeding background equipment structure schematic diagram of the embodiment two of the present application; Figure 3 It is a support frame structure schematic diagram of the embodiment two of the present application; Figure 4 It is a support frame overhead structure schematic diagram of the embodiment two of the present application; Figure 5 It is a feeding device structure front view of the present application; Figure 6 It is a feeding device structure side view of the present application; Figure 7 It is a mixer structure side view of the embodiment one of the present application; Figure 8 It is a mixer structure side view of the embodiment two of the present application; Figure 9 It is a mixer structure side view of the embodiment three of the present application; Figure 10 It is a mixer structure side view of the embodiment four of the present application; Figure 11 Figure 1 is a front view of a mixer structure according to an embodiment of the present application; Figure 12 Figure 4 is a front view of a mixer structure according to another embodiment of the present application; Figure 13 Figure 5 is a front view of a mixer structure according to yet another embodiment of the present application; Figure 14 Figure 6 is a schematic diagram of a powder injection pile feeding background equipment applied to a construction system according to the present application.

[0019] In the drawings: 1, gas supply unit; 2, feeding background main body; 3, powder injection pile drilling machine; 4, safety valve; 5, pressure gauge; 6, booster valve; 7, tank booster pipe; 8, feeding inlet; 9, feeding valve; 10, exhaust valve; 11, exhaust pipe; 12, tank; 13, motor; 14, rotating shaft; 15, helical blade; 16, main gas supply pipe; 17, mixer; 18, gas supply branch; 181, gas supply branch one; 182, gas supply branch two; 183, gas supply branch three; 19, feeding device; 191, boot cavity; 192, communication pipe; 20, feeding on-off valve; 21, air inlet pipe; 211, air inlet pipe one; 212, air inlet pipe two; 213, air inlet pipe three; 22, conveying pipeline; 23, support frame; 24, shaft sleeve; 25, gas circuit valve. DETAILED DESCRIPTION

[0020] First of all, those skilled in the art should understand that these embodiments are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adjust them as needed in order to adapt to specific application occasions.

[0021] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "fitted", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0022] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0023] Embodiment 1: As shown in the drawings Figure 1As shown, the powder jet pile feeding background equipment of the present application includes a tank 12, a gas path unit, a conveying pipeline 22, a feeding device 19, a mixer 17 and a control unit, the tank 12 is installed on a support, and the support is provided with a corresponding weighing sensor, which can monitor the weight change of the tank 12 in real time to realize real-time monitoring of the powder usage in the tank 12. The discharge port at the bottom of the tank 12 is connected with the feeding device 19, the mixer 17 and the conveying pipeline 22 in sequence, and the solidifying agent in the tank 12 enters the mixer 19 along the channels; the gas path unit is provided with high-pressure gas by a gas supply unit 1, and before entering the mixer 17, a main gas supply pipe 16 is divided into a plurality of gas supply branches 18 and connected with the same number of gas inlet pipes 21 on the mixer 17, so that the high-pressure gas and the solidifying agent powder form a gas-solid mixture in the mixer 17, which is sent to the drill bit nozzle position of the powder jet pile drilling machine 3 through the conveying pipeline 22, and then stirred into a pile.

[0024] As shown in the accompanying drawings, Figure 1 The powder jet pile feeding background equipment of the present application has the function of real-time adjustment of the solidifying agent powder conveying amount, which is based on that the tank 12 in the present application is a high-pressure tank, the side wall of the tank 12 is provided with a safety valve 4, a pressure gauge 5, a pressure increasing valve 6, a tank pressure increasing pipe 7, an inlet 8, an inlet valve 9, an exhaust valve 10 and an exhaust pipe 11, the main gas supply pipe 16 is further connected with a gas path valve 25, the outlet end of the feeding device 19 is connected with a feeding switch valve 20, and each switch valve is monitored and coordinated controlled by the control unit. When feeding, the tank 12 is pressurized, and the pressure is always kept higher than a certain value in the conveying pipeline 22, and under this pressure difference, the output amount of the solidifying agent in the tank 12 is stabilized within a certain value, which ensures the uniformity of the solidifying agent mixed per meter of pile length under the stable drilling speed; after the drilling machine is positioned, only one key is needed to start the construction, and the background control unit can automatically open and close the switch valves in the feeding stage, and when the feeding is completed, the switch valves in the construction are automatically opened and closed, and at the same time in the construction process, the control unit also adjusts the pressure in the tank 12 to ensure the uniformity of the solidifying agent mixing by monitoring the conveying amount and the drilling speed.

[0025] As Figure 5As shown, the opening and closing of the feeding switch valve 20 and the gas path valve 25 are programmed by the control unit, and the opening and closing time of the feeding switch valve 20 and the gas path valve 25 is 1.5 seconds, and the opening and closing sequence is that the feeding switch valve 20 is opened while the gas path valve 25 is closed, the feeding switch valve 20 is closed while the gas path valve 25 is opened, and the opening and closing is continuously alternating during the drilling process. This opening and closing rule offsets the time of the gas and the powder entering the conveying pipeline 22, forms a period of reduced pressure in the mixer 17, and reduces the resistance of the solidifying agent in the tank into the mixer 17. This opening and closing mode has the following effects: when the feeding switch valve 20 is opened and the gas path valve 25 is closed, the high-pressure gas in the conveying pipeline 22 stops entering the inside of the mixer 17, and a period of reduced pressure is generated in the mixer 17, at which time the solidifying agent powder can more smoothly enter the inside of the mixer 17; when the feeding switch valve 20 is closed and the gas path valve 25 is opened, the high-pressure gas will take away the powder in the mixer 17. In this way, the same amount of discharge can be ensured only by stable pressure, the feeding is more uniform, and at the same time, this intermittent feeding form avoids the gathering of a large amount of powder in the pipeline at the same position in another way, and reduces the possibility of pipe blockage.

[0026] As shown in Figure 5 , Figure 6 , the upper feeding port of the feeding device 19 at the bottom of the tank body 12 is circular, is connected with the discharge port of the tank body 12 through a flange, and the feeding device 19 is divided into two parts, the upper part is a boot-shaped cavity 191, and the lower part is a communication pipe 192 with a long slot. The bottom of the boot-shaped cavity 191 is gradually narrowed from top to bottom in the side cross section, and the bottom is connected with the long slot on the communication pipe 192. This structure can make the solidifying agent have a larger passing area when entering the communication pipe 192, and avoid the accumulation of the solidifying agent at this position.

[0027] As shown in Figure 7 , Figure 11 , the gas inlet pipe 21 and the gas supply branch 18 are two, that is, the gas inlet pipe one 211 and the gas inlet pipe two 212 are arranged on the side wall of the mixer 17 and are connected with the gas supply branch one 181 and the gas supply branch two 182 respectively. The gas inlet pipe one 211 and the gas inlet pipe two 212 are both 15 cm away from the left end of the mixer 17, and the included angle between the two gas inlet pipes 21 and the main pipeline of the mixer 17 is 45 degrees. Figure 7 As can be seen from Figure 7 , the two gas inlet pipes 21 are uniformly and symmetrically arranged on both sides of the mixer 17, and the axis direction of the gas inlet pipe 21 passes through the center of the mixer 17. The high-pressure gas discharged from the two gas inlet pipes 21 converges to form a main gas flow to convey the solidifying agent. The uniform distribution of the gas flow can be realized by the multiple gas inlet pipes 21 symmetrically in the same position, and the flow path of the solidifying agent powder is not disorderly.

[0028] As shown in Figure 14 , the operation method of the powder jet pile feeding background equipment in the construction in the embodiment is as follows: S1. Before starting piling, the control unit is first started by one button to fill the curing agent powder. The feeding switch valve 20 at the rear end of the feeding device 19 is closed, the feeding valve 9 and the exhaust valve 10 on the upper part of the tank body 12 are opened, the tank body boosting valve 6 is closed, and the curing agent is fed into the tank body 12 through the feeding port 8. When the curing agent weight reaches the set value, the control unit automatically stops feeding, closes the feeding valve 9 and the exhaust valve 10, and opens the tank body boosting valve 6; S2. After the above actions are completed, the control unit automatically controls the gas supply unit 1 to start providing high-pressure gas, pressurizing the tank body 12 to the set pressure through the tank body booster pipe 7 and adjusting it in real time. The main gas circuit valve 25 is opened, and the gas supply branches 18 are used to ventilate the delivery pipe 22 to achieve a stable delivery state; S3, operate the powder injection pile drilling rig 3, when the drill bit starts to drill downward, the feeding switch valve 20 is opened in linkage, and the main air circuit valve 25 is closed at the same time. During the drilling process of the drill bit, the feeding switch valve 20 and the main air circuit valve 25 are opened and closed according to the set time respectively, and the opening and closing frequency of the feeding switch valve 20 is used to control the delivery amount of the curing agent. The curing agent powder is stably transported to the delivery pipeline 22 through the feeding device 19 and the mixer 17 by the pressure in the tank, and a stable solid-gas mixed flow is formed by using multiple air inlet pipes 21. At the same time, the pressure in the tank will be adjusted with the drilling depth during the drilling process to ensure the uniformity of the curing agent injected into each section of the pile body; S4, when the powder injection pile drilling rig 3 drills and sprays powder to the design elevation, the pile bottom is mixed again, and the feeding switch valve 20 is closed while the drill is operated to stop feeding, and the air valve 25 reduces the opening and closing amplitude and supplies a small amount of air, and the drill is stopped to the surface to complete the construction of a single powder injection pile; S5, the powder injection pile drilling rig 3 moves to the next pile position, and repeats steps S1 to S4 to carry out the next pile construction.

[0029] Example 2: The following combination Figure 2 、 Figures 3 to 6 、 Figure 8 and Figure 14 The specific implementation of the first embodiment of the present invention is described in detail: The basic structure of the background equipment in this embodiment is similar to that in the first embodiment. The difference is that: Figure 2 As shown, in order to increase the adjustment range of the curing agent delivery amount, the present invention can also provide a rotating shaft 14 and a spiral blade 15 in the tank body 12. The rotating shaft 14 is arranged in the tank body 12 along its axis, and the upper end is rotatably connected to the top of the tank body 12 through a bearing assembly. A support frame 23 is provided on the inner wall of the bottom of the tank body 12, and the lower end of the rotating shaft 14 is rotatably connected to the middle of the support frame 23 through a bearing assembly. The support frame 23 here is an annular three-pronged support frame. During the rotation of the spiral blade 15, it does not affect the material discharge and can ensure the stability of the rotating shaft, thereby preventing the spiral blade from scraping the pipe wall during rotation.

[0030] When the pressure in the tank 12 reaches the limit and still cannot meet the required delivery amount, the motor 13 is driven to rotate, and the screw blade 15 is driven to rotate in the forward direction to increase the delivery amount by rotating with the material. This operation can also be performed by opening or closing the control unit according to the change in the real-time delivery amount. Since the screw blade cooperates with the pressure to carry the material in this embodiment, the interval feeding may cause the powder in the screw to be compacted, so the feeding switch valve 20 is always open, and the air path valve 25 adopts a cycle air supply mode of opening for 2 seconds and closing for 1 second.

[0031] As shown in Figure 8 In this embodiment, the air inlet pipe 21 and the air supply branch 18 are three, that is, the air inlet pipe one 211, the air inlet pipe two 212 and the air inlet pipe three 213 are arranged on the side wall of the mixer 17, which are connected with the air supply branch one 181, the air supply branch two 182 and the air supply branch three 183 respectively. The air inlet pipe one 211, the air inlet pipe two 212 and the air inlet pipe three 213 are all 10 cm away from the left end of the mixer 17, the angle between the air inlet pipe 21 and the main pipeline of the mixer 17 is 35 degrees, and the three air inlet pipes are uniformly and symmetrically arranged on the circumference side of the mixer 17, and the axis direction of the air inlet pipe 21 passes through the center of the mixer 17. The high-pressure gas discharged from the three groups of air inlet pipes converges to form a main gas flow to transport the curing agent; by symmetrically arranging the three air inlet pipes, the resultant force generated after each gas flow enters the delivery pipeline is maximum, which can ensure the delivery energy.

[0032] The operation method in this embodiment is the same as that in embodiment one, except that: S3, operate the powder jet pile drill 3, the drill bit starts to drill downward, at the same time, the feeding switch valve 20 is opened in linkage with the motor 13, the screw blade 15 cooperates with the pressure in the tank to adjust the rotation speed of the screw and the pressure, and the curing agent powder is stably delivered to the delivery pipeline 22 through the feeding device 19 and the mixer 17, and a stable solid-gas mixed flow is formed by using multiple air inlet pipes 21. In the drilling process, the screw blade 15 and the pressure in the tank will adjust the rotation speed of the screw and the pressure according to the drilling speed, to ensure the uniformity of the curing agent injected into each pile body; S4, when the powder jet pile drill 3 drills and sprays powder to the designed elevation, the pile bottom is stirred, and at the same time, the feeding switch valve 20 and the motor 13 are closed to stop feeding, the air path valve 25 reduces the opening and closing amplitude to supply a small amount of air, the drill is pulled to the ground to stop, and the construction of a single powder jet pile is completed.

[0033] Embodiment three: The basic structure of the background equipment in this embodiment is similar to that in embodiment one or embodiment two, except that: As shown in Figure 9As shown, in this embodiment, the mixer 17 is provided with air inlet pipe one 211 and air inlet pipe two 212, which are connected with air supply branch one 181 and air supply branch two 182 respectively, the air inlet pipe one 211 and air inlet pipe two 212 are both 20 cm away from the left end of the mixer 17, the angle between the air inlet pipe 21 and the main pipeline of the mixer 17 is 25 degrees, the two air inlet pipes are eccentrically symmetrical in the pipeline cross section, the axis direction of each air inlet pipe 21 has the same eccentricity from the center of the mixer 17, the high-pressure gas discharged from the two groups of air inlet pipes converges to form a main airflow to transport the curing agent; since the two air inlet pipes 21 are eccentrically symmetrical, the two airflows will form a rotating airflow after entering the interior of the mixer 17, this structure makes the rotating airflow energy at the mixer larger and the material carrying capacity stronger.

[0034] Meanwhile, the opening and closing of the feeding switch valve 20 and the air path valve 25 are programmed by the control unit, so that the opening and closing time of the feeding switch valve 20 and the air path valve 25 is 1 second, the opening and closing sequence is that the feeding switch valve 20 is opened while the air path valve 25 is closed, the feeding switch valve 20 is closed while the air path valve 25 is opened, and the process is continuously alternating during the drilling process.

[0035] The operation method in this embodiment is the same as that in embodiment one, and will not be repeated here.

[0036] Embodiment four: The basic structure of the background equipment in this embodiment is similar to that in embodiment one or embodiment two, and the difference is that: As shown in Figure 10 , Figure 12 In this embodiment, the mixer 17 is provided with three groups of air inlet pipes 21 and is connected with the air supply branch 18, the air inlet pipe one 211 is 5 cm away from the left end of the mixer 17, the air inlet pipe two 212 is 15 cm away from the left end of the mixer 17, the air inlet pipe three 213 is 25 cm away from the left end of the mixer 17, the angle between each air inlet pipe 21 and the main pipeline of the mixer 17 is 30 degrees, the three air inlet pipes 21 are eccentrically symmetrical in the pipeline cross section, the axis direction of each air inlet pipe 21 has the same eccentricity from the center of the mixer 17, the high-pressure gas discharged from the three groups of air inlet pipes 21 converges to form a main airflow to transport the curing agent; the mixer in this embodiment not only has more groups of air inlet pipes 21, but also is eccentrically symmetrical and has a certain spacing, so that the resistance of the high-pressure gas entering the mixer 17 is smaller and the effect of step-by-step acceleration is generated, which is more conducive to the transportation of the curing agent.

[0037] Meanwhile, the opening and closing of the feeding switch valve 20 and the air path valve 25 are programmed by the control unit, when the feeding program starts, the feeding switch valve 20 and the air path valve 25 are opened at the same time, among them, the feeding switch valve 20 is opened for 1 second and then closed for 1 second, the air path valve 25 is opened for 3 seconds and then closed for 1 second, the two valves cycle the process during the drilling process.

[0038] The operation method in this embodiment is the same as that in Embodiment 1, and will not be described again.

[0039] Embodiment Five The infrastructure of the background equipment in this embodiment is similar to that in Embodiments 1 or 2, and the difference is that: As shown in Figure 13 The mixer 17 in this embodiment is provided with a group of air inlet pipes 211 and the air supply branch 181. This structure is the simplest form. Since there is only one air supply branch 18, the air inlet pipe 211 is 5 cm away from the left end of the mixer 17, and the included angle between the air inlet pipe 211 and the main pipeline of the mixer 17 is 20-30 degrees, preferably 22 degrees. This structure can be applied in the powder jet pile engineering with small pile diameter and short pile length.

[0040] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A powder injection pile feeding backstage device for stably conveying powder, comprising a tank (12), an air circuit unit, a conveying pipeline (22), a feeding device (19), a mixer (17) and a control unit, characterized in that: The outlet of the tank (12) is connected to the upper inlet of the feeding device (19), the outlet of the feeding device (19) is connected to the inlet of the mixer (17), the outlet of the mixer (17) is connected to the inlet of the delivery pipe (22), and at least one air inlet pipe (21) distributed along the circumferential direction is connected to the outer peripheral wall of the mixer (17); the air circuit unit includes a main air supply pipe (16) and at least one air supply branch (18), the inlet of the main air supply pipe (16) The outlet of the main air supply pipe (16) is connected to the air supply unit (1), the outlet of the main air supply pipe (16) is connected to the corresponding air inlet pipe (21) through each air supply branch (18), and the outlet of the delivery pipe (22) is connected to the powder injection pile drilling rig (3); the curing agent powder in the tank body (12) enters the interior of the mixer (17) along the feeding device (19) under the action of internal pressure, and enters the delivery pipe (22) under the action of high-pressure gas injection from several air supply branches (18).

2. The powder injection pile feeding background equipment for stably conveying powder according to claim 1 is characterized by: A rotating shaft (14) is installed inside the tank body (12) along the central axis, a spiral blade (15) is provided on the outside of the middle and lower part of the rotating shaft (14), a support frame (23) is provided on the inner wall of the bottom of the tank body (12), the lower end of the rotating shaft (14) is rotatably connected to the support frame (23), and a motor (13) for driving the rotating shaft (14) to rotate is connected to the top of the tank body (12).

3. The powder injection pile feeding background equipment for stably conveying powder according to claim 1 is characterized in that: The gas circuit unit further comprises a tank body boosting pipe (7), one end of which is connected to the main gas supply pipe (16) or the gas supply unit (1), and the other end of which is connected to the top of the tank body (12), and a boosting valve (6) is connected to the tank body boosting pipe (7); a feed valve (9) for opening and closing the feed port (8), a safety valve (4), a pressure gauge (5) and an exhaust valve (10) for opening and closing the exhaust pipe (11) are also provided on the upper side wall of the tank body (12); a feed switch valve (20) is connected to the outlet end of the feeding device (19); and a gas circuit valve (25) for controlling the intake air flow is connected to the main gas supply pipe (16).

4. The powder injection pile feeding background equipment for stably conveying powder according to claim 3 is characterized by: The motor (13), air supply unit (1), boost valve (6), feed valve (9), exhaust valve (10), safety valve (4), pressure gauge (5), feed switch valve (20) and gas circuit valve (25) are all controlled by the control unit in a unified and coordinated manner; and during the construction process, the feed switch valve (20) and the gas circuit valve (25) are opened and closed regularly in sequence according to the set frequency.

5. The powder injection pile feeding background equipment for stably conveying powder according to claim 1 is characterized in that: The upper feed port of the feeding device (19) is connected to the discharge port of the tank body (12); the inner cavity of the feeding device (19) is a boot-shaped cavity (191) that gradually widens from top to bottom in the length direction, and the two sides of the boot-shaped cavity (191) in the width direction are inclined and converged from top to bottom toward one side of the mixer (17); the bottom of the boot-shaped cavity (191) is connected to a connecting pipe (192), and the connecting pipe (192) is connected to the inlet of the mixer (17).

6. The powder injection pile feeding background equipment for stably conveying powder according to any one of claims 1 to 5, characterized in that: The mixer (17) is a cylindrical structure, the connection angle between each of the air inlet pipes (21) and the mixer (17) is less than 90°, and each of the air inlet pipes (21) is inclined toward a side close to the feeding device (19).

7. The powder injection pile feeding background equipment for stably conveying powder according to claim 6 is characterized by: The air inlet pipes (21) are evenly distributed along the circumferential direction of the mixer (17), and the air inlet pipes (21) are arranged at the same distance from the front end of the mixer (17) or are arranged at equal distances along the length direction of the mixer (17).

8. The powder injection pile feeding background equipment for stably conveying powder according to claim 7 is characterized in that: The axial direction of each air inlet pipe (21) passes through the center line of the mixer (17).

9. The powder injection pile feeding background equipment for stably conveying powder according to claim 7 is characterized in that: The axial direction of each of the air inlet pipes (21) has the same eccentricity with the center of the mixer (17).

10. A control method for powder injection pile feeding background equipment for stable powder delivery according to claim 4, characterized in that: The specific process includes the following: S1. Before starting piling, the control unit starts to load the curing agent powder with one button, the feeding switch valve (20) at the rear end of the feeding device (19) is closed, the feeding valve (9) and the exhaust valve (10) on the upper part of the tank body (12) are opened, the tank body pressure boosting valve (6) is closed, and the curing agent is fed into the tank body (12) through the feeding port (8). When the weight of the curing agent reaches the set value, the control unit automatically stops feeding, closes the feeding valve (9) and the exhaust valve (10), and opens the tank body pressure boosting valve (6); S2. After the above actions are completed, the control unit automatically controls the gas supply unit (1) to start providing high-pressure gas, pressurizes the tank body (12) to the set pressure through the tank body booster pipe (7) and adjusts it in real time, the main gas circuit valve (25) opens, and uses each gas supply branch (18) to ventilate the delivery pipe (22) and achieve a stable delivery state; S3, operate the powder injection pile drilling rig (3), when the drill bit starts to drill downward, the feed switch valve (20) is linked to open, and the main gas circuit valve (25) is closed synchronously. During the drilling process, the feed switch valve (20) and the main gas circuit valve (25) are opened and closed according to the set time respectively, and the feeding amount of the curing agent is controlled by the opening and closing frequency of the feed switch valve (20). The curing agent powder is stably transported to the delivery pipe (22) through the feeding device (19) and the mixer (17) by the pressure in the tank, and a stable solid-gas mixed flow is formed by using multiple air inlet pipes (21). At the same time, during the drilling process, the pressure in the tank will be adjusted according to the drilling depth to ensure the uniformity of the curing agent injected into each section of the pile body; S4, when the powder injection pile drilling rig (3) drills down and sprays powder to the designed elevation, the pile bottom is re-mixed, and the feed switch valve (20) is closed to stop feeding while the drill is lifted. The air valve (25) reduces the opening and closing range to supply a small amount of air, and the drill is lifted to the surface and stopped, completing the construction of a single powder injection pile; S5, the powder injection pile drilling machine (3) moves to the next pile position, and repeats steps S1 to S4 to carry out the construction of the next pile body.

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