A de-bridging anti-blocking system based on a laval tube

Abstract

The utility model relates to bulk material's anti -blocking and unblocking technology field especially, relates to a kind of arch breaking anti -blocking system based on Laval pipe. Including the shock wave injection unit of being installed on the sidewall of bunker, the air inlet end of shock wave injection unit is connected electromagnetic pneumatic valve, electromagnetic pneumatic valve is connected with gas tank by air pipe, the air outlet end of shock wave injection unit is communicated with the inside of bunker, the shock wave injection unit includes Laval nozzle, spring ejector rod assembly is installed in Laval nozzle, the pre-tightening tension of spring in spring ejector rod assembly is pulled tight on the end face of Laval nozzle terminal end, Laval nozzle is equipped with contraction section, throat, expansion section and outlet section, outlet section is used to spray supersonic airflow and impact arch breaking. The structure makes that jet in outlet forms shock wave area, have strong impact force, high directivity, flow field controllability, significantly superior to conventional straight pipe nozzle or single-hole nozzle, especially suitable for breaking material arch, mouse hole, wall adhesion and other complex jamming mode.

Description

Technical fields:

[0001] This utility model relates to the field of anti-blocking and anti-blocking technology for bulk materials, and in particular to an arch-breaking and anti-blocking system based on Laval pipes. Background technology:

[0002] In bulk material handling industries such as chemical, building materials, power, metallurgy, and grain processing, granular materials are often stored and transferred through containers such as silos, bins, and hoppers. However, during the falling and unloading process of materials, poor flow or even blockage often occurs due to factors such as humidity, static electricity, and physical structure, which seriously affects production efficiency and safe operation.

[0003] Currently, common material blockage problems mainly include the following:

[0004] 1. Arching phenomenon: refers to the spontaneous formation of a stable arch-shaped structure above the discharge port of granular material, i.e., a "material bridge", which prevents the material above from continuing to flow. It often occurs when the particle size is large, the internal friction coefficient is high, or the discharge port size is small.

[0005] 2. Bridging (channeling) phenomenon: This refers to the phenomenon where materials fall through a narrow channel only in the central area, while materials around the center remain stationary, forming a "dead zone," also known as the "mouse hole" effect. This phenomenon is often seen in materials with high humidity or strong interparticle forces.

[0006] 3. Rat hole phenomenon: This refers to the formation of a cavity structure inside the particles, where only a local material falls and the outer particles form a covering layer. In severe cases, it can lead to the collapse of the material surface or interruption of flow.

[0007] 4. Adhesion phenomenon: Particles adhere to the silo wall, especially for powder materials with high moisture content and certain viscosity, which are more likely to accumulate or clump on the silo wall, thus aggravating material blockage.

[0008] Traditional unblocking methods, such as manual tapping, vibrators, electric hammers, or air cannons, suffer from high energy consumption, unstable impact force, short structural lifespan, or poor safety, making them unsuitable for long-term application in complex working conditions. In recent years, non-contact unblocking methods based on high-pressure airflow pulses have gained increasing attention. However, current jet-blowing unblocking devices lack sufficient high-pressure airflow and impact force to effectively handle stubborn blockages, especially at the bottom of cones or in complex, arched structures. Currently, there is no good solution to these problems.

[0009] In summary, how to improve the impact force of high-pressure airflow to deal with stubborn material blockage has become a technical problem that urgently needs to be solved in the industry. Utility model content:

[0010] To overcome the shortcomings of existing technologies, this invention provides a Laval tube-based anti-blocking and anti-arching system, which solves the problems of insufficient high-pressure airflow, lack of sufficient impact force, and inability to effectively handle stubborn blockages in previous jet cleaning devices.

[0011] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0012] A Laval nozzle-based arch-breaking and anti-clogging system includes several shock wave jetting units installed on the side wall of a silo. The air inlet of each shock wave jetting unit is connected to an electromagnetic pneumatic valve, which is connected to an air tank via an air pipe. The air outlet of each shock wave jetting unit is connected to the inside of the silo. Each shock wave jetting unit includes a Laval nozzle, and a spring-loaded rod assembly is installed inside the Laval nozzle. The pre-tension force generated by the spring in the spring-loaded rod assembly pulls the rod tight to the end face of the Laval nozzle. The Laval nozzle has a contraction section, a throat, an expansion section, and an outlet section. The outlet section is used to eject supersonic airflow for impact arch breaking.

[0013] The contraction section, throat, expansion section, and outlet section are inclined curved surfaces generated by 360° rotation. The included angle of the curve of the contraction section is 50°-70°, and the included angle of the curve of the expansion section is 10°-30°.

[0014] The spring push rod assembly includes a push rod movably disposed inside the Laval nozzle. A guide sleeve is fitted on the front side of the push rod, and a spring is fitted on the guide sleeve. The guide sleeve guides the movement through its end cooperating with the inner wall of the Laval nozzle. The end of the guide sleeve is provided with a vent hole. The inner wall of the Laval nozzle is provided with a stepped surface that limits the end of the guide sleeve. One end of the spring abuts against and limits the end of the guide sleeve, and the other end of the spring is limited by a spring limiting seat fitted on the push rod. An anti-loosening locking nut is tightened on the front end of the push rod to tighten the spring limiting seat.

[0015] The push rod and the end of the Laval nozzle are in contact at 90° or at an angle, with the angle of the angled contact being 30°-90°.

[0016] The Laval nozzle is equipped with a pressure sensor, which is connected to the PLC controller.

[0017] The end of the shockwave jet unit is screwed onto a round nut by threads. The outer wall of the round nut is circumferentially welded to the outer wall of the hopper. The hexagonal nut is tightened with the round nut to fix the shockwave jet unit onto the hopper.

[0018] The air inlet of the shock wave jet unit is connected to the electromagnetic pneumatic valve, the electromagnetic pneumatic valve to the air pipe, and the air pipe to the air tank through connectors with O-rings.

[0019] The gas tank is equipped with a gas tank filling port, a gas tank pressure gauge, and a gas tank pressure relief valve.

[0020] The exit section of the Laval nozzle has an air velocity of Mach 1.5 to 2.5, and the end of the exit section extends 5-20 mm inside the hopper wall.

[0021] The Laval nozzle is made of high-temperature resistant and wear-resistant alloy steel or ceramic structure.

[0022] The present invention adopts the above solution and has the following beneficial effects:

[0023] By employing a shockwave jet unit made with a Laval nozzle, the gas generates supersonic airflow and shockwave impact within the Laval nozzle. When the gas velocity reaches supersonic speed, a pressure gradient exists at the constriction of the Laval nozzle, allowing the air to continue accelerating in the expansion section. The supersonic gas forms a shock wave through the gap between the end face and the wall, utilizing the shock wave to achieve a powerful unblocking capability. The opening and closing of the electromagnetic pneumatic valve is controlled by a PLC controller, enabling unblocking in multiple areas as needed. This structure allows the jet to form a shockwave zone at the outlet, possessing strong impact force, high directivity, and controllable flow field, significantly superior to conventional straight pipe nozzles or single-hole nozzles. It is particularly suitable for breaking up complex blockages such as material arches, rat holes, and wall adhesion. Attached image description:

[0024] Figure 1 This is a schematic diagram of the structure of this utility model.

[0025] Figure 2 This is an explosion diagram of the shock wave jet unit of this utility model.

[0026] Figure 3 This is a cross-sectional view of the structure of the present invention, showing that the push rod and the end of the Laval nozzle are in contact at 90°.

[0027] Figure 4 This is a cross-sectional view of the structure of the present invention, showing that the push rod and the end of the Laval nozzle are in inclined contact.

[0028] Figure 5 This is a schematic diagram of the structure of the gas tank of this utility model.

[0029] Figure 6 This is the electrical schematic diagram of this utility model.

[0030] In the diagram, 1. hopper, 2. shock wave jet unit, 3. electromagnetic pneumatic valve, 4. air pipe, 5. air tank, 6. Laval nozzle, 7. contraction section, 8. throat, 9. expansion section, 10. outlet section, 11. push rod, 12. guide sleeve, 13. spring, 14. spring limit seat, 15. anti-loosening lock nut, 16. pressure sensor, 17. round nut, 18. hexagonal nut, 19. connector, 20. air tank filling port, 21. air tank pressure gauge, 22. air tank pressure relief valve. Detailed implementation method:

[0031] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0032] like Figure 1-6 As shown, a Laval nozzle-based anti-arching and anti-clogging system includes several shock wave jetting units 2 installed on the side wall of a silo 1. The shock wave jetting units 2 are fixed in key arching areas of the silo 1, such as the center of the cone bottom or the eccentric region. The air inlet of each shock wave jetting unit 2 is connected to an electromagnetic pneumatic valve 3, which is connected to a PLC controller. The electromagnetic pneumatic valve 3 is connected to an air tank 5 via an air pipe 4. The air outlet of each shock wave jetting unit 3 is connected to the interior of the silo 1. Each shock wave jetting unit 2 includes a Laval nozzle 6. A spring-loaded rod assembly is installed inside the Laval nozzle 6. The pre-tension force generated by the spring 13 in the spring-loaded rod assembly pulls the rod 11 tight to the end face of the Laval nozzle 6. The Laval nozzle 6 is provided with a contraction section 7, a throat 8, an expansion section 9, and an exit section 10. The exit section 10 is used to eject supersonic airflow to impact and break the arch. Under a high-pressure air source ≥0.5MPa, the gas forms a shock wave impact cone at the exit through the shock wave jet unit 2, which has concentrated energy penetration and is used to improve jet velocity and clear blockage penetration.

[0033] The Laval nozzle 6 accelerates the input high-pressure gas to supersonic speeds through its axisymmetric geometry, forming a high-speed airflow with shock wave characteristics. The Laval nozzle 6 is defined by two Laval curves symmetrically distributed around its central axis. These curves include a contraction section 7, a throat 8, a dilatation section 9, and a terminal exit section 10, with the throat 8 being the smallest cross-section. When the airflow velocity at the nozzle exit reaches or exceeds Mach 1, a shock wave expansion structure forms after the throat 8. During gas ejection, a high-energy shock wave flow field in a parallel direction is generated at the nozzle, exerting strong instantaneous shear and impact forces on the clogging material. The nozzle cross-section adopts a slit-like structure, formed by rotating the aforementioned Laval curves 360° around the nozzle's central axis to create an inclined surface. This structure exhibits excellent axisymmetric shock wave distribution characteristics. The curve angle of the contraction section 7 is preferably 50°-70°, and the curve angle of the dilatation section 9 is preferably 10°-30°. The minimum diameter of the throat 8 is precisely designed based on the gas source pressure and the target Mach number to ensure stable shock wave formation.

[0034] The spring push rod assembly includes a push rod 11 movably disposed inside the Laval nozzle 6. A guide sleeve 12 is fitted on the front side of the push rod 11, and a spring 13 is fitted on the guide sleeve 12. The guide sleeve 12 guides the movement by engaging with the inner wall of the Laval nozzle 6 at its end. The end of the guide sleeve 12 is provided with a vent hole. The inner wall of the Laval nozzle 6 is provided with a stepped surface that limits the end of the guide sleeve 12. One end of the spring 13 abuts against and limits the end of the guide sleeve 12, and the other end of the spring 13 is limited by a spring limiting seat 14 fitted on the push rod 11. An anti-loosening locking nut 15 is screwed onto the front end of the push rod 11 to tighten the spring limiting seat 14.

[0035] The top rod 11 and the end of the Laval nozzle 6 are in contact at 90° or at an angle, with the angle of the angled contact being 30°-90°.

[0036] The Laval nozzle 6 is equipped with a pressure sensor 16. The wiring harness of the pressure sensor 16 is connected to the corresponding sequential ports X4-X33 of the PLC controller input terminal, and the pressure signal is fed back to the PLC controller to facilitate identification of whether the shock wave blowing unit is faulty or the air source pressure is insufficient. If the pressure signal is too low, it will remind you to check whether the air tank pressure is low, and whether the spring 13 and the push rod 11 are faulty, which facilitates the inspection and maintenance of the system. When the PLC controller starts the electromagnetic pneumatic valve 3, the high-pressure gas is released quickly through the shock wave blowing unit 2, forming a powerful pulse to impact the blocked material in the chamber. If the shock wave blowing unit 2 is unobstructed, the pressure will drop rapidly in a very short time. If the blockage is not cleared or the shock wave blowing unit 2 is blocked by powder, the pressure drops slowly or even remains high. By installing the pressure sensor 16 to detect the pressure change at the moment of blowing, the working status of the shock wave blowing unit 2 can be judged in real time.

[0037] The end of the shock wave jet unit 2 is screwed onto the round nut 17 by threads. The outer wall of the round nut 17 is circumferentially welded to the outer wall of the hopper 1. During the welding process, the end face of the Laval nozzle 6 in the shock wave jet unit 2, which is connected to the top rod 11, is tangent to and leveled with the inner wall of the hopper 1. The hexagonal nut 18 is tightened with the round nut 17 to fix the shock wave jet unit 2 onto the hopper 1.

[0038] The air inlet of the shock wave jet unit 2 is connected to the electromagnetic pneumatic valve 3, the electromagnetic pneumatic valve 3 is connected to the air pipe 4, and the air pipe 4 is connected to the air tank 5 through a connector 19 with an O-ring, which supports quick installation and disassembly and is suitable for bulk material storage and transportation equipment such as silos, hoppers, and chutes with different structures and sizes.

[0039] The gas tank 5 is equipped with a gas tank filling port 20, a gas tank pressure gauge 21, and a gas tank pressure relief valve 22, which are used to display the pressure and provide pressure relief protection when the gas tank pressure is too high.

[0040] The outlet section of the Laval nozzle 6 has an air velocity of Mach 1.5 to 2.5, and the end of the outlet section extends 5-20 mm inside the wall of the hopper 1 to prevent material blockage.

[0041] The Laval nozzle 6 is made of high-temperature resistant and wear-resistant alloy steel or ceramic structure.

[0042] Working principle:

[0043] The electromagnetic pneumatic valve 3 is normally closed. The wiring harness of the electromagnetic pneumatic valve 3 is connected to any one of the output ports Y0-Y29 of the PLC controller. The PLC controller input is AC220 AC power, and the output voltage is converted to 24V by the AC-DC converter built into the PLC controller. The PLC controller realizes the sequential energization of Y0-Y29 and controls the energization time and energization interval of each output port. By adjusting the energization time and energization interval of Y0-Y29, the pulse time and pulse interval of different electromagnetic pneumatic valves 3 in the system can be adjusted. The pulse time and pulse interval can be set and adjusted through the touch screen display. At the same time, the blowing sequence of the shock wave blowing unit can be adjusted by changing the wiring sequence of different electromagnetic pneumatic valve harnesses to different ports of Y0-Y29. When ports Y0-Y29 are energized, the corresponding electromagnetic pneumatic valve 3 opens. High-pressure gas enters the shock wave jetting unit 2 from the gas tank 5 through the gas pipe 4 and the electromagnetic pneumatic valve 3. It is accelerated by the Laval nozzle 6, pushing open the push rod 11 and ejecting from the end. During gas injection, a high-energy shock wave flow field in a parallel direction is generated at the nozzle, which exerts strong instantaneous shear force and impact force on the blockage material. When the electromagnetic pneumatic valve 3 is de-energized, the airflow is closed, and the pre-tension of the spring 13 resets the push rod 11 to fit tightly against the end of the Laval nozzle 6, closing the shock wave jetting unit 2. When the pulse interval time is up, the next port is energized, controlling the jetting of the shock wave jetting unit 2 at the next position of the hopper 1.

[0044] The above specific embodiments should not be construed as limiting the scope of protection of this utility model. For those skilled in the art, any alternative improvements or modifications made to the embodiments of this utility model shall fall within the scope of protection of this utility model.

[0045] Any aspects of this utility model not described in detail are known to those skilled in the art.

Claims

1. A system for preventing arch breakage and blockage based on Laval tubes, characterized in that: The system includes several shockwave jet units installed on the side wall of the silo. The air inlet of each shockwave jet unit is connected to an electromagnetic pneumatic valve, which is connected to an air tank via an air pipe. The air outlet of each shockwave jet unit is connected to the inside of the silo. Each shockwave jet unit includes a Laval nozzle. A spring push rod assembly is installed inside the Laval nozzle. The preload force generated by the spring in the spring push rod assembly pulls the push rod tight on the end face of the Laval nozzle. The Laval nozzle has a contraction section, a throat, an expansion section, and an outlet section. The outlet section is used to eject supersonic airflow to impact and break the arch. The contraction section, throat, expansion section, and outlet section are inclined curved surfaces generated by 360° rotation. The included angle of the curve of the contraction section is 50°-70°, and the included angle of the curve of the expansion section is 10°-30°. The spring push rod assembly includes a push rod movably disposed inside the Laval nozzle. A guide sleeve is fitted on the front side of the push rod, and a spring is fitted on the guide sleeve. The guide sleeve guides the movement through its end cooperating with the inner wall of the Laval nozzle. The end of the guide sleeve is provided with a vent hole. The inner wall of the Laval nozzle is provided with a stepped surface that limits the end of the guide sleeve. One end of the spring abuts against and limits the end of the guide sleeve, and the other end of the spring is limited by a spring limiting seat fitted on the push rod. An anti-loosening locking nut is tightened on the front end of the push rod to tighten the spring limiting seat. The Laval nozzle is equipped with a pressure sensor, which is connected to the PLC controller.

2. The arch-breaking and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The push rod and the end of the Laval nozzle are in contact at 90° or at an angle, with the angle of the angled contact being 30°-90°.

3. The anti-arching and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The end of the shockwave jet unit is screwed onto a round nut by threads. The outer wall of the round nut is circumferentially welded to the outer wall of the hopper. The hexagonal nut is tightened with the round nut to fix the shockwave jet unit onto the hopper.

4. The arch-breaking and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The air inlet of the shock wave jet unit is connected to the electromagnetic pneumatic valve, the electromagnetic pneumatic valve to the air pipe, and the air pipe to the air tank through connectors with O-rings.

5. The anti-arching and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The gas tank is equipped with a gas tank filling port, a gas tank pressure gauge, and a gas tank pressure relief valve.

6. The anti-arching and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The exit section of the Laval nozzle has an air velocity of Mach 1.5 to 2.5, and the end of the exit section extends 5-20 mm inside the hopper wall.

7. The anti-arching and anti-clogging system based on Laval tubes according to claim 1, characterized in that: The Laval nozzle is made of high-temperature resistant and wear-resistant alloy steel or ceramic structure.

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