A low-slump deck waterproofing concrete hopper

Abstract

The embodiment of the utility model provides a kind of low slump bridge deck waterproof protective layer concrete hopper suitable for, it is related to concrete hopper technical field.The low slump bridge deck waterproof protective layer concrete hopper suitable for includes: hopper body, the hopper body is connected with discharge pipe;The sidewall of the hopper body is provided with vibration device, and the discharge pipe is inclined to the hopper body state.By the periodic micro-displacement of vibration device in the inner wall of hopper body, the concrete particles attached to the surface of inner wall are loosened and peeled, and the fluidity of concrete whole can be significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of concrete hopper technology, specifically to a concrete hopper suitable for low slump bridge deck waterproofing protective layer. Background Technology

[0002] To ensure the durability of the railway bridge structure, a highly ductile, flexible waterproof base layer adapted to temperature differences and structural deformation was designed, with a high-strength, rigid waterproof material used as the protective layer. As the structure directly exposed to various service environments and train travel spaces, the performance of the railway bridge deck waterproof protective layer material not only affects the durability of the bridge structure but also directly impacts the safe operation of trains. The railway bridge deck waterproof protective layer is a cast-in-place concrete structure characterized by its small thickness (minimum only 4cm), large surface area (over 100m² per span), and high design strength grade (C40). Its design purpose is to prevent water seepage from the bridge surface and damage to the beam structure, requiring excellent crack resistance, impermeability, and freeze-thaw resistance. Reducing the concrete slump upon placement improves concrete homogeneity, significantly enhancing the crack resistance and freeze-thaw resistance of the concrete structure. Preliminary research has determined that the optimal durability is achieved when the concrete slump of the railway bridge deck waterproof protective layer is controlled within the range of 80mm to 120mm.

[0003] However, for the traditional bucket elevator method of concrete pouring, the fluidity of fresh concrete is poor when the slump is too low. The existing concrete hopper has a gentle slope of discharge pipe, which makes it difficult to discharge the concrete. This can easily lead to blockage of the hopper outlet or uneven discharge, which reduces construction efficiency and affects the overall continuity and density of the bridge deck paving. This is not conducive to the promotion and application of low slump concrete in the waterproof protective layer of railway bridge decks. Utility Model Content

[0004] According to an embodiment of this utility model, a concrete hopper suitable for waterproof protective layers on low-slump bridge decks is provided. This addresses the problems mentioned in the background section.

[0005] In a first aspect, this utility model provides a concrete hopper suitable for waterproof protective layers on low-slump bridge decks.

[0006] The concrete hopper for low slump bridge deck waterproofing protective layer includes: a hopper body, on which a discharge pipe is connected; a vibration device is provided on the side wall of the hopper body, and the discharge pipe is inclined relative to the hopper body.

[0007] Preferably, the angle between the axis of the discharge pipe and the vertical center line of the hopper body is 120°~180°, but not 180°.

[0008] Preferably, it further includes a gate assembly connected to the discharge pipe, the gate assembly being used to control the opening or closing of the discharge port of the discharge pipe.

[0009] Preferably, the gate assembly includes a control rod, a first gear, a second gear, and two baffle plates. The first gear and the second gear are rotatably connected to the side wall of the discharge pipe and are meshed together. The two baffle plates have arc-shaped cross-sections and are fixedly connected to the first gear and the second gear, respectively. The control rod is fixedly connected to the first gear. When the two baffle plates are close to each other and in contact, the discharge port of the discharge pipe is in a closed state. When the two baffle plates are far apart, the discharge port of the discharge pipe is in an open state.

[0010] Preferably, the vibration device includes a motor and a cam; the motor is mounted on the side wall of the hopper body, and the cam is connected to the output end of the motor.

[0011] Preferably, it further includes an inflation component and an air cannon component; the inflation component is connected to the cam, and the inflation component is also connected to the air cannon component, the inflation component being used to inflate the air cannon component.

[0012] Preferably, the inflation assembly includes an air chamber, a piston, a push rod, a connecting rod, a drive arm, a first check valve, and a second check valve; The air chamber is fixedly installed on the side wall of the hopper body, the piston is slidably installed in the air chamber, the push rod is fixedly connected to the piston, the end of the push rod away from the piston is rotatably connected to the connecting rod, the end of the connecting rod away from the push rod is rotatably connected to the drive arm, and the end of the drive arm away from the connecting rod is fixedly connected to the cam. The first check valve and the second check valve are connected to the air chamber and are located on the side of the piston away from the push rod.

[0013] Preferably, the air cannon assembly includes an air tank, a pressure valve, and an air outlet pipe; the air tank is connected to the first one-way valve via a pipeline, the pressure valve is connected to the air tank, the air outlet pipe is connected to the pressure valve, the air outlet pipe extends into the interior of the hopper body, and the air outlet of the air outlet pipe faces the discharge pipe.

[0014] One or more technical solutions provided in this application have at least the following technical effects or advantages: This invention provides a concrete hopper suitable for low-slump bridge deck waterproofing protective layers. A vibration device generates periodic micro-displacements on the inner wall of the hopper, loosening and peeling away concrete particles adhering to the inner surface. This significantly improves the overall fluidity of the concrete, ensuring a continuous and uniform descent of the concrete within the hopper, thereby enhancing the discharge rate and stability. Especially for low-slump concrete, this vibration device helps prevent stratification and segregation caused by localized static conditions, while ensuring the homogeneity and air content control of the concrete, thus guaranteeing consistency of the concrete composition during the discharge process.

[0015] It should be understood that the description in this utility model description section is not intended to limit the key or essential features of the embodiments of this utility model, nor is it intended to restrict the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the various embodiments of the present invention will become more apparent from the accompanying drawings and the following detailed description. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein: Figure 1 A first-view perspective three-dimensional structural schematic diagram of a concrete hopper suitable for a low-slump bridge deck waterproof protective layer according to an embodiment of the present invention is shown. Figure 2 A second-view perspective three-dimensional structural schematic diagram of a concrete hopper suitable for a low-slump bridge deck waterproof protective layer according to an embodiment of the present invention is shown. Figure 3 A cross-sectional structural schematic diagram of a concrete hopper suitable for a low-slump bridge deck waterproofing protective layer is shown according to an embodiment of the present invention. Figure 4 A three-dimensional structural schematic diagram of a gate assembly for a low-slump bridge deck waterproof protective layer concrete hopper is shown according to an embodiment of the present invention. Figure 5 The diagram shows a first-view perspective three-dimensional structural schematic of an air-filling assembly, an air cannon assembly, and a vibration device for a concrete hopper suitable for a low-slump bridge deck waterproof protective layer according to an embodiment of the present invention. Figure 6 The diagram shows a second-view perspective three-dimensional structural schematic of an air-filling assembly, an air cannon assembly, and a vibration device for a concrete hopper suitable for a low-slump bridge deck waterproof protective layer according to an embodiment of the present invention. Figure 7The diagram shows a partial cross-sectional view from a third perspective of an air-filling assembly, an air cannon assembly, and a vibration device for a concrete hopper suitable for a low-slump bridge deck waterproofing protective layer, according to an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures 1-Hopper body, 11-Support, 2-Discharge pipe, 3-Gate assembly, 31-Control lever, 32-First gear, 33-Second gear, 34-Baffle plate, 4-Inflation assembly, 41-Air chamber, 42-Piston, 43-Top rod, 44-Connecting rod, 45-Drive arm, 46-First check valve, 47-Second check valve, 5-Air cannon assembly, 51-Air tank, 52-Pressure valve, 53-Air pipe, 6-Pipeline, 7-Vibration device, 71-Motor, 72-Cam. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0020] like Figures 1 to 7As shown, the concrete hopper for low-slump bridge deck waterproofing protective layer includes a hopper body 1, with a discharge pipe 2 connected to the hopper body 1; a support 11 is also connected to the hopper body 1. A vibration device 7 is installed on the side wall of the hopper body 1, and the discharge pipe 2 is inclined relative to the hopper body 1. Through the above structural design, the hopper can achieve a stable and smooth feeding process while maintaining the low slump characteristics of concrete. The hopper body 1, as a temporary storage container for concrete, has an optimized internal space shape that allows the concrete to flow from top to bottom under gravity and be discharged through the discharge pipe 2. Because low-slump concrete has poor fluidity and high friction and cohesion between internal aggregates, it is easy to cause accumulation and blockage if it relies solely on gravity flow. Therefore, a vibration device 7 is installed on the side wall of the hopper body 1. The high-frequency vibration generated by the vibration device 7 can effectively break the static friction between aggregates inside the concrete, causing the concrete particles to rearrange at the micro level, reducing their internal bonding resistance, and thus promoting the concrete to form a continuous flow state inside the hopper.

[0021] During the feeding process, the vibration device 7 generates periodic micro-displacements on the inner wall of the hopper body 1, loosening and peeling away the concrete particles adhering to the inner wall surface. This significantly improves the overall fluidity of the concrete, ensuring a continuous and uniform downward flow of the concrete within the hopper body 1, thereby enhancing the discharge rate and stability. Especially for low-slump concrete, the vibration device 7 helps prevent stratification and segregation caused by localized static conditions, while ensuring the homogeneity and air content control of the concrete, thus ensuring the consistency of concrete composition during the feeding process.

[0022] Furthermore, in this embodiment, the axis of the discharge pipe 2 forms an angle of 120° to 180° with the vertical center line of the hopper body 1, but not exactly 180°. For example... Figure 3 As shown, in this embodiment, when the included angle is 135°, the discharge pipe 2 is arranged at a relatively large inclination angle, making it easier for the concrete to flow out under the combined action of gravity and inertia. This angle setting ensures a shorter natural sliding path for the concrete while avoiding the discharge pipe 2 being too steep, which would cause the concrete impact to concentrate and form a "flow stream" phenomenon. Through a reasonable inclination angle design, the flow resistance of the concrete in the discharge pipe 2 is significantly reduced, enhancing the self-discharge capacity of low-slump concrete and allowing it to smoothly pass through the discharge pipe opening into the construction area.

[0023] like Figure 1 , Figure 2 and Figure 4As shown, in this embodiment, a gate assembly 3 connected to the discharge pipe 2 is also included. The gate assembly 3 is used to control the opening or closing of the discharge port of the discharge pipe 2. The gate assembly 3 includes a control rod 31, a first gear 32, a second gear 33, and two baffle plates 34. The first gear 32 and the second gear 33 are rotatably connected to the side wall of the discharge pipe 2 and are meshed together. The two baffle plates 34 have arc-shaped cross-sections and are fixedly connected to the first gear 32 and the second gear 33, respectively. The control rod 31 is fixedly connected to the first gear 32. When the two baffle plates 34 are close to each other and in contact, the discharge port of the discharge pipe 2 is in a closed state. When the two baffle plates 34 are far apart, the discharge port of the discharge pipe 2 is in an open state.

[0024] In the specific operation, when it is necessary to open the discharge pipe 2, the operator pulls the control lever 31 upwards, causing the control lever 31 to drive the first gear 32, which is fixedly connected to it, to rotate. The rotation of the first gear 32 drives the second gear 33 to rotate in the opposite direction through meshing transmission. The synchronous linkage of the two gears causes the two baffle plates 34, which are fixedly connected to them respectively, to rotate in opposite directions, thereby moving the two baffle plates 34 away from each other and gradually opening the discharge port of the discharge pipe 2. During this process, the outer arc surface of the arc-shaped baffle plate 34 matches the inner wall contour of the discharge port, making the opening action smooth and preventing the instantaneous pouring of concrete due to sudden opening. As the distance between the two baffle plates 34 increases, the effective flow area of ​​the discharge port increases accordingly, and the concrete flow rate can be linearly adjusted, thereby achieving continuous and controllable adjustment of the concrete discharge rate.

[0025] When it is necessary to stop the discharge, the operator can release the lifting action of the control lever 31. Under its own weight and damping, the control lever 31 gradually returns to its vertical downward position. During this process, the control lever 31 drives the first gear 32 to rotate in the opposite direction. The first gear 32 meshes with the second gear 33, causing the second gear 33 to also move synchronously in the opposite direction, thereby driving the two baffle plates 34 to move closer together. When the two baffle plates 34 gradually approach and finally form a closed contact at the discharge port, the discharge channel is completely blocked, achieving precise stopping of concrete discharge. Due to the arc-shaped structure design of the baffle plate 34, it can closely fit the arc cross-section of the discharge port when closed, thereby forming a uniform sealing surface, preventing concrete residue from leaking or dripping, and ensuring the sealing reliability of the discharge port. In addition, the transmission structure of the gate assembly 3 is coordinated with the inclination direction of the discharge pipe 2 in the direction of force, so that the opening and closing actions can be carried out naturally with the assistance of gravity, thereby reducing the operating resistance and avoiding complex external power devices.

[0026] In this embodiment, the vibration device 7 includes a motor 71 and a cam 72. The motor 71 is mounted on the side wall of the hopper body 1, and the cam 72 is connected to the output end of the motor 71. When the motor 71 starts, its output shaft drives the cam 72 to rotate at high speed. Since the cam 72 is not a regular circle but has a certain eccentricity or elliptical profile, it continuously generates uneven centrifugal force during rotation. This centrifugal force periodically acts on the side wall of the hopper body 1, causing it to generate combined radial and tangential vibrations, thereby breaking the static equilibrium state of the low-slump concrete in the hopper and promoting the redistribution of concrete particles to form a loose flow state. During the vibration process, the rotation frequency and eccentricity of the cam 72 play a decisive role in the vibration intensity and effect.

[0027] Bridge deck waterproofing protective layers typically employ low-slump, high-viscosity protective materials, such as high-performance concrete or waterproof mortar. These materials have a low water-cement ratio, poor fluidity, rapid initial setting, and high internal friction, making them prone to accumulation, adhesion, or arch-like blockages within the hopper and discharge pipe. Especially at bridge construction sites, the complex environment and significant temperature variations can cause localized drying shrinkage and clumping of the material within a short period, leading to poor material flow and severely impacting the continuity and smoothness of the waterproofing layer construction. Therefore, in this embodiment, the concrete hopper suitable for low-slump bridge deck waterproofing protective layers further includes an inflation component 4 and an air cannon component 5; the inflation component 4 is connected to the cam 72 and also to the air cannon component 5, and is used to inflate the air cannon component 5. The air cannon assembly 5 is well-suited to this type of construction environment. It periodically stores pressure in the air tank 51 and, when the pressure valve 52 is opened, instantaneously sprays high-pressure air through the air outlet pipe 53, creating a strong airflow impact force to intermittently clear the concrete stuck in the discharge pipe 2. This "air cannon" action can effectively break up blockages caused by the high viscosity and rapid water loss of the material without changing the concrete mix ratio, maintaining smooth material flow. This ensures uniform pouring and continuous operation during the construction of the bridge deck waterproof protective layer, significantly improving the forming quality and construction stability of the waterproof layer.

[0028] The rotation of cam 72 activates the inflation component 4, which inflates the air cannon component 5. Once inflation is complete, the internal pressure of the air cannon component 5 gradually increases. As the pressure reaches the preset release pressure value, the internal valve structure of the air cannon component 5 automatically opens, instantly releasing high-pressure gas. The high-speed jet of air propagates along the inner wall of the discharge pipe 2, creating a directional pneumatic thrust. This thrust not only acts directly on the concrete substrate but also impacts and peels away residual concrete particles adhering to the inner wall of the discharge pipe 2, keeping the inner wall of the discharge pipe 2 clear and significantly reducing the risk of concrete stagnation or accumulation within the pipe. Simultaneously, the short-duration action of the airflow does not damage the homogeneity of the concrete because its action time is extremely short and the jetting direction is consistent with the concrete discharge direction, thus maintaining the overall consistency and stability of the concrete flow while achieving the unblocking effect.

[0029] While the vibrating device 7 vibrates the hopper body 1 via the motor 71 and cam 72, the air cannon assembly 5 periodically sprays high-pressure gas after inflation. The combined effect of these two energy forms promotes the loosening and flow of concrete particles within different frequency ranges. The continuous micro-vibration generated by the vibrating device 7 reduces the static friction of the concrete, enhancing its overall fluidity, while the instantaneous impact of the air cannon assembly 5 breaks up any potential local "material bridges" or "blockages," thus ensuring the smooth flow of the entire discharge channel.

[0030] In this embodiment, the inflation assembly 4 includes an air chamber 41, a piston 42, a push rod 43, a connecting rod 44, a drive arm 45, a first one-way valve 46, and a second one-way valve 47. The air chamber 41 is fixedly installed on the side wall of the hopper body 1. The piston 42 is slidably installed in the air chamber 41. The push rod 43 is fixedly connected to the piston 42. The end of the push rod 43 away from the piston 42 is rotatably connected to the connecting rod 44. The end of the connecting rod 44 away from the push rod 43 is rotatably connected to the drive arm 45. The end of the drive arm 45 away from the connecting rod 44 is fixedly connected to the cam 72.

[0031] The first one-way valve 46 and the second one-way valve 47 are connected to the air chamber 41 and are located on the side of the piston 42 away from the push rod 43.

[0032] The rotation of cam 72 will drive drive arm 45 to rotate, drive arm 45 will drive connecting rod 44 to move, connecting rod 44 will drive push rod 43 to reciprocate in air chamber 41, push rod 43 will drive piston 42 to reciprocate in air chamber 41. When air chamber 41 moves away from second one-way valve 47, negative pressure is formed in air chamber 41, drawing outside air into air chamber 41. When piston 42 moves towards second one-way valve 47, second one-way valve 47 cannot discharge air, air is compressed and will enter first one-way valve 46, and first one-way valve 46 will fill air into air cannon assembly 5.

[0033] As the inflation assembly 4 continuously inflates the air tank 51 through the pipeline 6, the internal air pressure of the air tank 51 gradually increases. When the air pressure reaches the opening pressure set by the pressure valve 52, the pressure valve 52 is rapidly opened under the action of pressure difference. The high-pressure gas in the air tank 51 is released instantaneously through the pressure valve 52 and flows at high speed into the interior of the hopper body 1 along the air outlet pipe 53. Since the air outlet of the air outlet pipe 53 faces the discharge pipe 2, the ejected high-pressure airflow forms a strong directional "air cannon" effect. This airflow applies a pulse thrust to the concrete flow in the discharge pipe 2 in a very short time, causing the concrete to accelerate instantaneously along the discharge direction, thereby effectively relieving the blockage caused by low slump, aggregate clogging, or a gentle slope of the discharge pipe.

[0034] During the construction of the bridge deck waterproof protective layer, continuous and uniform pouring of the waterproof concrete layer is usually required. Long-term interruptions during construction are not permitted, as these can easily lead to cold joints, delamination, or a decline in waterproof performance. Based on this, the air cannon assembly 5 designed in this application is particularly well-suited to this construction requirement. The air cannon assembly 5 periodically stores pressure in the air tank 51 and automatically opens when the pressure valve 52 reaches the set pressure. High-pressure gas is intermittently sprayed into the discharge pipe 2 through the air outlet pipe 53, forming a periodic "air cannon" impact. This structure enables uninterrupted construction during continuous concrete pouring while simultaneously using intermittent airflow to clear the discharge pipe 2, effectively preventing blockages caused by high consistency or early setting of low-slump concrete. Unlike traditional hoppers that require shutdown for cleaning, this application uses a dynamic self-cleaning mechanism to ensure continuous construction, better meeting the actual requirements of "continuous pouring and uninterrupted operation" in bridge deck waterproof protective layer construction.

[0035] While high-pressure gas is being injected, air flows through the inner wall of the discharge pipe 2, forming a thin air film. This air film temporarily reduces the friction coefficient between the concrete and the pipe wall, allowing the concrete particles to achieve higher fluidity in a short time. This instantaneous aerodynamic drag reduction effect helps the concrete pass smoothly through the narrow section of the discharge pipe 2 and prevents flow fluctuations caused by concrete adhesion to the pipe wall, thus ensuring a stable and continuous overall discharge process. Because the pressure valve 52 has an automatic reset function, when the air pressure in the air tank 51 drops below the set closing pressure, the pressure valve 52 will close again, and the system will re-enter the inflation phase to accumulate energy for the next injection. This cycle repeats continuously, achieving an automated, periodic aerodynamic flow-aiding process that continuously improves concrete discharge performance without manual operation.

[0036] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A concrete hopper suitable for low-slump bridge deck waterproofing protective layer, comprising a hopper body (1), wherein a discharge pipe (2) is connected to the hopper body (1); characterized in that, The side wall of the hopper body (1) is provided with a vibration device (7), and the discharge pipe (2) is inclined relative to the hopper body (1).

2. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 1, characterized in that, The angle between the axis of the discharge pipe (2) and the vertical center line of the hopper body (1) is 120°~180°, but not 180°.

3. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 1, characterized in that, It also includes a gate assembly (3) connected to the discharge pipe (2), the gate assembly (3) being used to control the opening or closing of the discharge port of the discharge pipe (2).

4. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 3, characterized in that, The gate assembly (3) includes a control rod (31), a first gear (32), a second gear (33), and two baffle plates (34). The first gear (32) and the second gear (33) are rotatably connected to the side wall of the discharge pipe (2), and the first gear (32) and the second gear (33) are meshed. The cross-section of the two baffle plates (34) is arc-shaped. The two baffle plates (34) are fixedly connected to the first gear (32) and the second gear (33) respectively. The control rod (31) is fixedly connected to the first gear (32). When the two baffle plates (34) are close to each other and in contact, the discharge port of the discharge pipe (2) is in a closed state. When the two baffle plates (34) are far apart from each other, the discharge port of the discharge pipe (2) is in an open state.

5. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 1, characterized in that, The vibration device (7) includes a motor (71) and a cam (72); the motor (71) is installed on the side wall of the hopper body (1), and the cam (72) is connected to the output end of the motor (71).

6. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 5, characterized in that, It also includes an inflation assembly (4) and an air cannon assembly (5); the inflation assembly (4) is connected to the cam (72), and the inflation assembly (4) is also connected to the air cannon assembly (5), the inflation assembly (4) being used to inflate the air cannon assembly (5).

7. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 6, characterized in that, The inflation assembly (4) includes an air chamber (41), a piston (42), a push rod (43), a connecting rod (44), a drive arm (45), a first check valve (46), and a second check valve (47). The air chamber (41) is fixedly installed on the side wall of the hopper body (1), the piston (42) is slidably installed in the air chamber (41), the push rod (43) is fixedly connected to the piston (42), the end of the push rod (43) away from the piston (42) is rotatably connected to the connecting rod (44), the end of the connecting rod (44) away from the push rod (43) is rotatably connected to the drive arm (45), and the end of the drive arm (45) away from the connecting rod (44) is fixedly connected to the cam (72). The first check valve (46) and the second check valve (47) are connected to the air chamber (41) and are located on the side of the piston (42) away from the push rod (43).

8. The concrete hopper for low-slump bridge deck waterproofing protective layer according to claim 7, characterized in that, The air cannon assembly (5) includes an air tank (51), a pressure valve (52), and an air outlet pipe (53); the air tank (51) is connected to the first one-way valve (46) through a pipeline (6), the pressure valve (52) is connected to the air tank (51), the air outlet pipe (53) is connected to the pressure valve (52), the air outlet pipe (53) extends into the interior of the hopper body (1), and the air outlet of the air outlet pipe (53) faces the discharge pipe (2).

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