Multistage flap valve for pneumatic conveying

Abstract

The utility model provides a kind of multistage flap valve for pneumatic conveying, it not only can realize phase difference closure, zero power consumption, passive self-locking, adaptive opening and closing, but also can realize low leakage sealing under import and export pressure difference working condition while continuously conveying material.It includes valve body, first stage flap, second stage flap, connecting rod, first stage flap and second stage flap are also connected with the reset mechanism for making first stage flap and second stage flap recover to closed state, limit slot is equipped in the bottom of first stage flap, one end of connecting rod is arranged in limit slot, the other end of connecting rod is rotatably connected with second stage flap, connecting rod moves in limit slot along with the downward rotation of first stage flap, and when connecting rod reaches the limit position in limit slot, connecting rod pushes down second stage flap and makes second stage flap open.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic conveying equipment technology, specifically a multi-stage flap valve for pneumatic conveying. Background Technology

[0002] Pneumatic conveying utilizes the energy of airflow to transport granular materials along the airflow direction within a closed pipeline. Traditional pneumatic conveying systems mostly use rotary feeders, which have the following drawbacks: during operation, there is a large amount of leakage airflow through the valve body and rotor gap of the rotary feeder, as well as backflow airflow carried by the rotor's own cavity during rotation; the shaft seals at both ends of the rotary feeder rotor are prone to wear and leakage; external drive energy is required, the structure is complex, maintenance costs are high, and additional explosion-proof measures are required in explosion-proof areas; there is a high risk of seal failure for powder materials, especially fine powders.

[0003] While existing multi-stage flap valves can solve some of the problems mentioned above, they still have certain shortcomings. For example, the double-layer flap unloading valve disclosed in patent CN208413267U includes upper and lower flaps. The upper and lower flaps are connected by a connecting rod and other parts to achieve the effect of closing the lower flap when the upper flap is open and closing the upper flap when the lower flap is open, thereby achieving the effect of airlock. However, the above structure can only realize the intermittent conveying of materials, which affects the working efficiency of the conveying system. Utility Model Content

[0004] To address the problem that existing multi-stage flap valves cannot achieve continuous material conveying, this utility model provides a multi-stage flap valve for pneumatic conveying, which can achieve low leakage sealing under inlet and outlet pressure difference conditions while continuously conveying materials.

[0005] The technical solution is as follows: A multi-stage flap valve for pneumatic conveying includes a valve body with inlets and outlets at its upper and lower ends, a first-stage flap located above the inside of the valve body, a second-stage flap located below the inside of the valve body, and a connecting rod. The first-stage flap and the second-stage flap are rotatably connected to one side of the valve body, and a connecting rod connects the first-stage flap and the second-stage flap. When the first-stage flap or the second-stage flap is closed, the first-stage flap or the second-stage flap cuts off the conveying channel inside the valve body by contacting the other side of the valve body. The first-stage flap and the second-stage flap are also connected to a reset mechanism for returning the first-stage flap and the second-stage flap to the closed state. The first-stage flap has a limiting groove at its bottom, one end of the connecting rod is disposed in the limiting groove, and the other end of the connecting rod is rotatably connected to the second-stage flap. The connecting rod moves in the limiting groove as the first-stage flap rotates downward, and when the connecting rod reaches the limit position in the limiting groove, the connecting rod pushes the second-stage flap downward and opens the second-stage flap.

[0006] Furthermore, a kinetic energy dissipation cavity is provided above the opening formed by the opening of the second-stage flap in the valve body. The kinetic energy dissipation cavity is located between the first-stage flap and the second-stage flap, and a baffle plate is provided in the kinetic energy dissipation cavity that is arranged obliquely downward.

[0007] Furthermore, the reset mechanism connected to the first-stage flap is a counterweight block, with one end of the first-stage flap extending out of the valve body and connected to the counterweight block; the reset mechanism connected to the second-stage flap is a reset spring, with one end connected to the inner wall of the valve body and the other end connected to the bottom of the second-stage flap. When the second-stage flap is in a closed or open state, the reset spring is in a compressed state.

[0008] Furthermore, the valve body is provided with a sealing block to prevent the flap from rotating upward.

[0009] Furthermore, the inner wall of the kinetic energy dissipation cavity is provided with hemispherical protrusions.

[0010] Furthermore, a cleaning component is installed in the valve body corresponding to the opening formed by the opening of the second-stage flap. The cleaning component includes a base and a scraper. The base is installed in the valve body, and the scraper is hinged to the base. When the second-stage flap is fully opened, there is a certain gap between the scraper and the second-stage flap. The scraper contacts the second-stage flap during the closing process and flips as the second-stage flap is pushed. The scraper is used to scrape off the material at the end of the second-stage flap during the flipping process.

[0011] Furthermore, the scraper is also connected to a compression spring, which is used to push the scraper against the second-stage flap when the second-stage flap is closed and in contact with the scraper.

[0012] Furthermore, the first-stage flap is provided with a sealing strip one on its side, and the second-stage flap is provided with a sealing strip two on its side.

[0013] Beneficial effects: The above structure enables a phase-difference linkage effect between the first-stage and second-stage flaps. The second-stage flap opens only after the first-stage flap has been open for a period of time. Since a certain amount of material has already accumulated on the second-stage flap by this time, a material sealing effect can be formed between the openings of the two-stage flaps when the material is discharged. This not only reduces the impact of airflow backflow on the material, but also allows the first and second-stage flaps to open simultaneously, ensuring continuous material conveying. In addition, by setting a kinetic energy dissipation cavity at the opening of the second-stage flap, the backflowing gas can be disturbed, greatly reducing the gas velocity and kinetic energy, further minimizing the impact of airflow backflow on the material. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a diagram showing the flip panel in open / closed state.

[0016] Figure 3 This is a schematic diagram of the kinetic energy dissipation cavity structure;

[0017] Figure 4 This is a schematic diagram of the cleaning component structure. Detailed Implementation

[0018] like Figure 1 , Figure 2 The multi-stage flap valve for pneumatic conveying, as shown, includes a valve body 1 with an inlet 101 and an outlet 102 at its upper and lower ends, a first-stage flap 2 located inside the upper part of the valve body 1, a second-stage flap 3 located inside the lower part of the valve body 1, and a connecting rod 301. The upper surfaces of the first-stage flap 2 and the second-stage flap 3 are lined with a low-friction coefficient material to facilitate material falling. The first-stage flap 2 and the second-stage flap 3 are rotatably connected (e.g., hinged) to one side of the valve body 1, and the connecting rod 301 connects the first-stage flap 2 and the second-stage flap 3. When the first-stage flap 2 or the second-stage flap 3 is opened, the valve body 1 can open. When plate 3 is closed, the first-stage flap 2 or the second-stage flap 3 cuts off the conveying channel inside the valve body 1 by contacting the other side of the valve body 1. In order to prevent the flap from flipping upward, a sealing block 204 can be set inside the valve body 1 to block the flap. Alternatively, the inclined valve body 1 shown in the figure can be used in conjunction with the flap to prevent the flap from flipping upward. At the same time, in order to ensure sealing, the sides of the first-stage flap 2 and the second-stage flap 3 are provided with sealing strips. The sealing strips can be made of fluororubber and have a pre-compression of 1.2 to 1.8 mm to ensure the sealing between the side of the flap and the valve body 1.

[0019] The first-stage flap 2 and the second-stage flap 3 are also connected to a reset mechanism for returning the first-stage flap 2 and the second-stage flap 3 to the closed state. In this application, the reset mechanism connected to the first-stage flap 2 can be a counterweight 201. One end of the first-stage flap 2 connected to the valve body 1 extends out of the valve body 1 and is connected to the counterweight 201. The reset mechanism connected to the second-stage flap 2 can be a reset spring 302. One end of the reset spring 302 is connected to the inner wall of the valve body 1, and the other end is connected to the bottom of the second-stage flap 2. When the second-stage flap 2 is in the closed state or the open state, the reset spring 302 is in the compressed state. The reset spring 302 provides sufficient thrust to the second-stage flap 2 to make it return to the closed state after opening. It can also provide sufficient thrust to the second-stage flap 2 to prevent the second-stage flap 2 from opening prematurely.

[0020] The bottom of the first-stage flap 2 is provided with a limiting groove 203. One end of the connecting rod 301 is set in the limiting groove 203, and the other end of the connecting rod 301 is rotatably connected to the second-stage flap 3. The connecting rod 301 moves in the limiting groove 203 as the first-stage flap 2 rotates downward. When the connecting rod 301 reaches the limit position in the limiting groove 203, the connecting rod 301 pushes the second-stage flap 3 downward and opens the second-stage flap 3, thereby realizing the phase difference linkage effect between the first-stage flap 2 and the second-stage flap 3.

[0021] Combination Figure 1-3 As shown, a kinetic energy dissipation cavity 4 is provided above the opening formed by the opening of the second-stage flap 3 inside the valve body 1. The kinetic energy dissipation cavity 4 is located between the first-stage flap 2 and the second-stage flap 3. The inner wall of the kinetic energy dissipation cavity 4 is provided with hemispherical protrusions 401. A baffle plate 402 is provided inside the kinetic energy dissipation cavity 4 and is arranged obliquely downward. Preferably, the angle between the baffle plate 402 and the valve body 1 is 45-75°. The diameter of the hemispherical protrusions 401 is 10-14mm, and they are distributed in a diamond array with a spacing of 25-35mm.

[0022] Combination Figure 1 , Figure 2 , Figure 4 A cleaning component 5 is installed inside the valve body 1 at the opening formed by the opening of the second-stage flap 3. The cleaning component 5 includes a base 501 and a scraper 502. The scraper 502 can be a polytetrafluoroethylene scraper. The base 501 is installed inside the valve body 1. The scraper 502 and the base 501 are hinged together by a hinge 503. When the second-stage flap 3 is fully opened, there is a certain gap between the scraper 502 and the second-stage flap 3 to provide space for the material to fall. The scraper 502 contacts the second-stage flap 3 during the closing process and flips with the push of the second-stage flap 3. The scraper 502 is used to scrape off the material at the end of the second-stage flap 3 during the flipping process. The scraper 502 is also connected to a compression spring 504. The compression spring 504 is used to push the scraper 502 against the second-stage flap 3 when the second-stage flap 3 is closed and contacts the scraper 502.

[0023] The following example illustrates the working principle of this solution. During operation, the material first enters through inlet 101. When the weight of the material entering inlet 101 exceeds the counterweight 201 on the left side of the first-stage flap 2, it triggers the downward opening of the first-stage flap 2. As soon as the first-stage flap 2 opens downward, it drives the connecting rod 301 to move to the left along the limiting groove 203. Due to the guiding effect of the limiting groove 203, the connecting rod 301 will not push the second-stage flap 3 downward at this time. The second-stage flap 3 can remain closed under the action of the reset mechanism. When the opening angle of the first-stage flap 2 reaches 20-25°, the connecting rod 301 just reaches the leftmost side of the limiting groove 203. At the same time, it applies downward pressure to the second-stage flap 3, thereby driving the second-stage flap 3 to open. The second-stage flap 3 opens with a delay through the connecting rod 301, ensuring that at least one barrier exists, so that the second-stage flap 3 does not open immediately at the same time as the first-stage flap 2.

[0024] As more and more material enters the inlet 101, the opening angle of the first-stage flap 2 becomes larger and larger. Under the action of the limit switch, the maximum opening angle of the first-stage flap 2 within the valve body 1 is 75°. When the first-stage flap 2 opens to a certain angle, the second-stage flap 2 also opens accordingly under the action of the connecting rod 301, with a maximum opening angle of 25°. The above method can realize the phase difference linkage of the two-stage flaps, that is, the first-stage flap 2 is opened first, and then the second-stage flap 3 is opened. In this embodiment, the opening phase difference between the first-stage flap 2 and the second-stage flap 3 is 20-25°, and the closing time difference is 0.3 to 0.8 seconds.

[0025] After both stages of flaps are opened, the material falls continuously down along the two stages of flaps and is discharged from the valve body outlet 102. At the same time, the pressurized backflow gas at the valve body outlet 102 first backflows into the kinetic energy dissipation chamber 4. In the kinetic energy dissipation chamber 4, the backflow gas is subjected to multiple impacts by the turbulent disturbance of the hemispherical protrusion 401 and the deflection and change of direction by the baffle 402, which greatly reduces the airflow velocity and kinetic energy. The backflow gas passing through the kinetic energy dissipation chamber 4 is then discharged through the first stage flap 2 and the second stage flap 4. After the material flows through the gap between the first-stage flap 2 and the inner cavity of the valve body 1 in the cavity between the plates 3, the remaining kinetic energy and flow velocity are greatly reduced. In addition, the material sealing effect formed by the filling between the opening gaps of the two-stage flaps when the material is fed is very small. The proportion of residual gas that can eventually backflow from the valve body outlet 102 to the valve body inlet 101 is very small. The openings of the two-stage flaps, together with the baffle 401 in the kinetic energy dissipation cavity 4, actually form multiple turns of the airflow, resulting in a labyrinth seal effect.

[0026] After material discharge is complete, the first-stage flap 2 automatically closes due to the weight of the configuration block. Simultaneously, the closing of the first-stage flap 2 triggers the interlocking closure of the second-stage flap 3. At the same time, the reset mechanism at the bottom of the second-stage flap 3 also pushes it to close. During the closing process of the second-stage flap 3, the scraper 502 at the bottom of the cleaning component 5 begins to scrape the end of the second-stage flap 3, removing residual material. The compression spring 504 ensures that the scraper 502 remains firmly against the second-stage flap 3, guaranteeing a cleanliness effect. This solution, through phase difference closure, zero power consumption, self-locking without external intervention, and adaptive opening and closing of the multi-stage flaps, along with the kinetic energy dissipation cavity and cleaning system, achieves low-leakage sealing and continuous material conveying under inlet and outlet pressure difference conditions, ensuring efficient material conveying.

[0027] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A multi-stage flap valve for pneumatic conveying, comprising a valve body with inlets and outlets at its upper and lower ends respectively, a first-stage flap located above the interior of the valve body, a second-stage flap located below the interior of the valve body, and a connecting rod, wherein the first-stage flap and the second-stage flap are rotatably connected to one side of the valve body, and a connecting rod connects the first-stage flap and the second-stage flap; when the first-stage flap or the second-stage flap is closed, the first-stage flap or the second-stage flap cuts off the conveying channel inside the valve body by contacting the other side of the valve body; the first-stage flap and the second-stage flap are also connected to a reset mechanism for returning the first-stage flap and the second-stage flap to the closed state, characterized in that: The bottom of the first-stage flap is provided with a limiting groove. One end of the connecting rod is disposed in the limiting groove, and the other end of the connecting rod is rotatably connected to the second-stage flap. The connecting rod moves in the limiting groove as the first-stage flap rotates downward. When the connecting rod reaches the limit position in the limiting groove, the connecting rod pushes the second-stage flap downward and opens the second-stage flap.

2. A multi-stage flap valve for pneumatic conveying according to claim 1, characterized in that: The valve body is provided with a kinetic energy dissipation cavity above the opening formed by the opening of the second stage flap. The kinetic energy dissipation cavity is located between the first stage flap and the second stage flap, and a baffle plate is provided in the kinetic energy dissipation cavity.

3. A multi-stage flap valve for pneumatic conveying according to claim 1 or 2, characterized in that: The reset mechanism connected to the first-stage flap is a counterweight. One end of the first-stage flap, which is connected to the valve body, extends out of the valve body and is connected to the counterweight. The reset mechanism connected to the second-stage flap is a reset spring. One end of the reset spring is connected to the inner wall of the valve body, and the other end is connected to the bottom of the second-stage flap. When the second-stage flap is in a closed or open state, the reset spring is in a compressed state.

4. A multi-stage flap valve for pneumatic conveying according to claim 1 or 2, characterized in that: The valve body is equipped with a sealing block to prevent the flap from rotating upwards.

5. A multi-turn flap valve for pneumatic conveying according to claim 2, characterized in that: The inner wall of the kinetic energy dissipation cavity is provided with hemispherical protrusions.

6. A multi-level flap valve for pneumatic conveying according to claim 1 or 2, characterized in that: A cleaning component is installed in the valve body at the opening formed by the opening of the second-stage flap. The cleaning component includes a base and a scraper. The base is installed in the valve body, and the scraper is hinged to the base. When the second-stage flap is fully opened, there is a certain gap between the scraper and the second-stage flap. The scraper contacts the second-stage flap during the closing process and flips as the second-stage flap is pushed. The scraper is used to scrape off the material at the end of the second-stage flap during the flipping process.

7. A multi-turn flap valve for pneumatic conveying according to claim 6, characterized in that: The scraper is also connected to a compression spring, which is used to push the scraper against the second-stage flap when the second-stage flap is closed and in contact with the scraper.

8. A multi-turn flap valve for pneumatic conveying according to claim 1, characterized in that: The first-stage flap is provided with a sealing strip one on its side, and the second-stage flap is provided with a sealing strip two on its side.

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