Positive pressure air seal machine based on Venturi effect

Abstract

The embodiment of the utility model discloses a positive pressure air seal machine based on the Venturi effect. The positive pressure air seal machine comprises a feeding chamber and an accelerating chamber located at the bottom of the feeding chamber. Wherein the accelerating chamber is funnel-shaped and comprises a contraction section and an expansion section, the sectional area of the contraction section is gradually reduced along the material flow direction, and the sectional area of the expansion section is gradually increased along the material flow direction; the contraction section is communicated with a positive-pressure airflow pipe, an outlet of the positive-pressure airflow pipe faces the expansion section, and the expansion section is communicated with a material conveying pipeline; a local negative pressure area is formed at the contraction section of the acceleration chamber and used for actively sucking materials and forming material-gas two-phase flow through mixing of positive pressure airflow and the materials. According to the positive pressure air seal machine, the funnel type acceleration chamber is adopted, the contraction section and the expansion section are combined to form a Venturi structure, under the forward airflow intervention condition, negative pressure is generated in the acceleration chamber, the stability of material conveying is enhanced, meanwhile, the mixing uniformity of materials and airflow can be improved, flowing is facilitated, and faults are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air lock, in particular to a positive pressure air lock based on Venturi effect. BACKGROUND

[0002] The positive pressure air lock (or called air lock, rotary valve) is the core feeding equipment of the positive pressure pneumatic conveying system, and is widely used in the conveying scene of powder and particle materials such as flour, grain, feed and chemical particles. The traditional positive pressure air lock includes a shell, a rotor, an end cover and an acceleration chamber. The positive pressure airflow enters the air lock from the bottom or the side to drive the rotor to rotate and feed the material. The material is pushed to the acceleration chamber by the rotor blade and mixed with the high-speed airflow to form a two-phase flow and enter the conveying pipeline. The material is continuously or intermittently forced to feed into the material conveying pipeline in a positive pressure state to realize efficient conveying.

[0003] The existing positive pressure air lock design mainly has the following deficiencies: for example, the acceleration chamber of the traditional air lock usually adopts a straight cylinder or a simple flared structure, which cannot provide sustained and stable acceleration power for the material, resulting in insufficient kinetic energy of the material during conveying, and problems such as conveying delay and increased energy consumption; for another example, due to the inaccurate control of the airflow direction inside the acceleration chamber, the positive pressure airflow is easy to form counterflow (backflow) at the bottom of the air lock, which interferes with the normal feeding of the material. The backflow will cause the material to accumulate and stay in the acceleration chamber or the rotor, and in severe cases, it will cause equipment jamming and even mechanical failure, affecting production efficiency and system reliability; in addition, the existing acceleration chamber lacks optimization design of the mixing path of the airflow and the material, and the material mainly relies on gravity to fall into the airflow, resulting in low mixing efficiency and easy separation of the material and the airflow, which leads to large fluctuation of the conveying concentration and affects the conveying stability.

[0004] In view of the above problems, it is urgent to design a positive pressure air lock to realize stable acceleration, backflow suppression and efficient mixing of airflow through structural optimization, improve conveying efficiency, reduce failure rate and adapt to diversified working conditions. CONTENT OF THE INVENTION

[0005] The main purpose of the present application is to provide a positive pressure air lock based on Venturi effect, which aims to solve the technical problem of poor two-phase conveying efficiency of the existing air lock.

[0006] To achieve the above purpose, the present application provides a positive pressure air lock based on Venturi effect, which includes a feeding chamber and an acceleration chamber located at the bottom of the feeding chamber; wherein,

[0007] The acceleration chamber is funnel-shaped and includes a converging section and a diverging section. The cross-sectional area of the converging section gradually decreases along the material flow direction, and the cross-sectional area of the diverging section gradually increases along the material flow direction.

[0008] The contraction section is communicated with a positive pressure airflow pipe, an outlet of the positive pressure airflow pipe is directed to the expansion section, and the expansion section is communicated with a material conveying pipe.

[0009] The acceleration chamber forms a local negative pressure area at the contraction section, so as to actively suck in the material and mix the material with the airflow to form a material-air two-phase flow.

[0010] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the inlet of the positive pressure airflow pipe is located at the side of the acceleration chamber, and the outlet of the positive pressure airflow pipe forms a preset included angle with the material flow direction.

[0011] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the connection between the contraction section and the expansion section is a throat section, the cross-sectional area of the throat section is the minimum cross-sectional area of the acceleration chamber, so as to concentrate the airflow velocity and enhance the local negative pressure effect.

[0012] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the cross-sectional area and length of the throat section are adjustable.

[0013] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the blade surface of the rotor adopts an arc-shaped structure or a streamline structure.

[0014] For example, in the positive pressure deduster provided in at least one embodiment of the present application, a guide plate is arranged at the outlet of the expansion section or the position communicated with the material conveying pipe.

[0015] For example, in the positive pressure deduster provided in at least one embodiment of the present application, a wear-resistant coating is arranged on the inner wall of the shell.

[0016] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the length ratio of the contraction section to the expansion section ranges from 1:1.5 to 1:3.

[0017] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the outlet direction of the acceleration chamber is vertically downward or horizontally.

[0018] For example, in the positive pressure deduster provided in at least one embodiment of the present application, the feeding chamber includes a shell, an end cover arranged on the shell, and a rotor arranged in the shell, the rotor being used to convey the material to the acceleration chamber.

[0019] The positive pressure air lock device has the following beneficial effects: the Venturi structure formed by the converging section and the diverging section of the funnel-shaped acceleration chamber avoids the sudden decrease of airflow velocity caused by the sudden change of the cross-sectional area of the acceleration chamber, maintains the stability of high-speed airflow, provides continuous conveying power for the material, shortens the conveying time and reduces the energy consumption; at the same time, based on the Bernoulli effect, a local negative pressure area is formed in the acceleration chamber to actively adsorb the material, promote the rapid and uniform mixing of the material and high-speed airflow, and avoid the stratified retention of the material; the improvement of the acceleration chamber structure and the airflow path can also reduce the accumulation of the material at the air lock device, inhibit the interference of the back airflow on the discharging, and reduce the equipment failure risk. The positive pressure air lock device solves the problems of airflow deceleration, back airflow interference and poor layout adaptability of the traditional positive pressure air lock device through the funnel-shaped acceleration chamber structure, the local negative pressure generation mechanism and the adjustable design of the outlet direction, realizes efficient, stable and flexible material conveying effect, and has remarkable industrial application value. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 It is an overall structure schematic diagram of an embodiment of the positive pressure air lock device of the present application.

[0022] Figure 2 It is an overall structure schematic diagram of an embodiment of the positive pressure air lock device of the present application. Figure 1 It is a structure sectional view of the positive pressure air lock device.

[0023] Figure 3 It is an acceleration chamber structure schematic diagram of an embodiment of the positive pressure air lock device of the present application.

[0024] Reference signs: 10, acceleration chamber; 110, converging section; 120, diverging section; 121, guide plate; 130, throat; 140, positive pressure airflow inlet; 150, positive pressure airflow outlet; 20, shell; 30, rotor; 40, end cover; 50, material conveying pipeline.

[0025] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0027] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0028] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixing", etc. should be understood in a broad sense, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] In addition, if the present application embodiments involve "first", "second", etc. description, the "first", "second", etc. description is only for description purpose, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0030] The application is to solve the problem of unstable airflow, reverse airflow and uneven mixing of material and gas in the existing positive pressure air lock due to insufficient structural design, which affects the conveying efficiency. An embodiment of a positive pressure air lock based on Venturi effect is proposed, which includes a feeding chamber and an acceleration chamber 10 located at the bottom of the feeding chamber. The feeding chamber includes a shell 20, a rotor 30, an end cover 40, the acceleration chamber 10 is funnel-shaped, including a convergent section 110 and a divergent section 120, the cross-sectional area of the convergent section 110 gradually decreases along the material flow direction, and the cross-sectional area of the divergent section 120 gradually increases along the material flow direction. The convergent section 110 is communicated with a positive pressure airflow pipe, the outlet of the positive pressure airflow pipe faces the divergent section 120, and the divergent section 120 is communicated with a material conveying pipe 50. The acceleration chamber 10 forms a local negative pressure area at the convergent section 110, which is used to actively suck in the material and mix with the material through the positive pressure airflow to form a two-phase flow of material and gas.

[0031] Referring to Figure 1 , the positive pressure air lock is an upper and lower structure, the upper half is a discharging mechanism, including a rotor 30, an end cover 40 and a shell 20, a motor and a sealing element, etc., which is also a material inlet; the lower half is mainly an acceleration chamber 10, which is also a material outlet. It should be noted that the structure of the upper half can refer to the related structure of the conventional positive pressure air lock in the prior art.

[0032] Referring to Figure 2 , the acceleration chamber 10 is funnel-shaped and includes a convergent section 110 and a divergent section 120 in the direction from top to bottom. In the convergent section 110, a positive pressure airflow is accessed through a positive pressure airflow pipe penetrating into the acceleration chamber 10, one end of the positive pressure airflow pipe is a positive pressure airflow inlet 140, and the other end is a positive pressure airflow outlet 150. The direction of the positive pressure airflow outlet 150 faces the divergent section 120, and the divergent section 120 is communicated with a material conveying pipe 50 (i.e. the material outlet). It should be noted that in addition to the embodiment shown in the figure, the funnel-shaped acceleration chamber 10 can also be realized by Figure 2 , it should be understood that the acceleration chamber structure with Venturi effect composed of the convergent section 110 and the divergent section 120 can be realized in the positive pressure air lock, and the implementation form of the positive pressure air lock of the embodiment is not limited to the figures shown. Figure 3

[0033] ​In operation, the Venturi structure formed by the contraction section 110 and the expansion section 120 results in a gradual decrease in cross-sectional area in the contraction section 110, leading to an increased airflow velocity. This generates the Bernoulli effect, creating a localized negative pressure zone in the acceleration chamber 10 to actively adsorb materials. In the expansion section 120, the gradually increasing cross-sectional area prevents a sudden drop in airflow velocity caused by abrupt changes in cross-section, maintaining the stability of the high-speed airflow. Simultaneously, within the acceleration chamber 10, the material and high-speed airflow mix rapidly and uniformly, preventing material stratification and retention. Through improvements in the funnel-shaped structure and positive pressure airflow path of the acceleration chamber 10, the Venturi effect provides stable material delivery and velocity while reducing material accumulation at the airlock, suppressing backflow interference with material discharge, and lowering the risk of equipment failure.

[0034] In the above embodiments, the duct configuration for positive pressure airflow can be varied, such as a coaxial direct insertion type, or other types. Figure 2 In the lateral inlet type, the positive pressure airflow inlet 140 is located on the side circumferential surface of the acceleration chamber 10, allowing it to penetrate into the acceleration chamber 10 and then flow out, with the outflow direction of the positive pressure airflow facing the expansion section 120 (e.g., Figure 2 For example, it is better to make it form a certain angle with the material flow direction to improve the mixing degree of airflow and material, prevent material accumulation, and affect conveying efficiency.

[0035] Furthermore, in Figure 2 In the illustrated embodiment, the connection between the contraction section 110 and the expansion section 120 is the throat 130. The cross-sectional area of ​​the throat 130 is the minimum cross-sectional area of ​​the acceleration chamber 10, used to concentrate the airflow velocity and enhance the local negative pressure effect. As the connection structure between the contraction section 110 and the expansion section 120 of the funnel-shaped accelerator, the throat 130 plays an important role in controlling the fluid velocity and flow rate in the Venturi effect. The smaller its cross-sectional area, the greater the spatial pressure difference, the stronger the negative pressure effect, and the more effectively it concentrates the airflow and increases the flow velocity.

[0036] Specifically, the size of the throat 130 is adjustable to accommodate the flow requirements of different materials. For example, by changing the diameter or cross-sectional shape of the throat, or by setting a movable throat liner such as a sliding baffle or a replaceable throat ring, the minimum cross-sectional area through which the airflow passes can be adjusted to suit the particle size and density requirements of different materials; or, by adjusting the extension length of the throat along the airflow direction, adopting a segmented throat design, adding or removing connecting sections, or adjusting the axial position of the throat components, the total length of the throat 130 can be changed to optimize the stability of airflow acceleration and negative pressure generation.

[0037] In one embodiment, the blade surface of the rotor 30 adopts an arc-shaped or streamlined structure. For example, the arc-shaped rotor 30 blades can be spirally twisted along the axial direction of the rotor 30, while the blade cross-section is arc-shaped, so that the helix angle matches the airflow direction. The streamlined rotor 30 blades can make the blade as a whole a smooth continuous arc shape, with a consistent radius of curvature from the root to the tip of each blade, forming a streamlined structure similar to an "airfoil cross-section". With the design of arc-shaped or streamlined rotor 30 blades, the separation phenomenon between the airflow and the blade surface and the frictional resistance can be reduced, the contact area can be increased, swirling flow can be formed, the mixing of materials and airflow can be promoted, and the carrying efficiency of airflow on materials can be improved.

[0038] In one embodiment, a guide vane is provided at the outlet of the expansion section 120 or at a location communicating with the material conveying pipe 50. The guide vane ensures a smooth two-phase flow of material and gas, enhances the backdraft suppression effect, and maintains conveying stability. Specifically, the guide vane can be configured as a fixed arc-shaped guide vane or a multi-plate guide vane design, etc. Figure 3 As shown, the fixed arc-shaped guide plate can be fixed on the inner wall of the expansion section 120 outlet of the acceleration chamber 10, with the arc surface facing the airflow direction, guiding the two-phase flow of material and gas along the axial direction of the conveying pipeline, reducing turbulence and backflow; the multi-plate guide design has 3-5 small guide plates evenly distributed around the circumference of the expansion section 120 outlet, each guide plate is fan-shaped or airfoil-shaped, and they form a guide channel by staggered arrangement, dispersing the airflow pressure gradient and avoiding backflow caused by local high pressure areas.

[0039] In one embodiment, the inner wall of the housing 20 is provided with a wear-resistant coating to reduce wear on the housing 20 caused by high-speed materials. Based on the working scenario, environment, and coating process, the wear-resistant coating in this embodiment can be a ceramic coating (such as silicon carbide, chromium carbide), a metal-based composite material coating (such as tungsten carbide-cobalt, nickel-based alloy), or a polymer coating (such as polyurethane). Possibly, for specific material conveying process characteristics, such as the presence of temperature-affected conditions, a composite coating, such as a ceramic-metal composite coating, can also be selected to extend the lifespan of the housing 20 and reduce maintenance costs.

[0040] In one embodiment, the length ratio of the contraction section 110 to the expansion section 120 ranges from 1:1.5 to 1:3 to achieve a smooth transition in airflow velocity and stable generation of the negative pressure zone. The gradually decreasing cross-sectional area (shorter length) rapidly increases the airflow velocity, forming a high-speed airflow core region, providing initial momentum for negative pressure generation; while the longer expansion section 120 gradually reduces the airflow velocity, allowing the pressure to recover smoothly, avoiding abrupt changes in cross-sectional area that could lead to airflow separation or turbulence, and reducing energy loss. In this embodiment, the length ratio range of the contraction section 110 to the expansion section 120 ensures a controllable airflow velocity gradient, maintaining a stable negative pressure zone (near the throat 130), and preventing blockages or backflow caused by pressure fluctuations during material transport.

[0041] In an embodiment, the outlet direction of the acceleration chamber 10 is arranged vertically downward or horizontally, to adapt to different working conditions. In this embodiment, the outlet direction of the acceleration chamber 10 can be adjusted and designed according to the actual working environment. For example, in addition to the vertical downward direction in the foregoing embodiments, the outlet direction can also be arranged horizontally. Possibly, the outlet direction can be adjusted in cooperation with the material conveying pipeline 50 to form a required outlet direction.

[0042] The above is only an optional embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields, or direct / indirect application in other related technical fields within the concept of the present application, using the contents of the present application specification and drawings, are included in the patent protection scope of the present application.

Claims

1. A positive pressure air lock based on the Venturi effect, characterized in that, The device comprises a feeding chamber and an accelerating chamber located at the bottom of the feeding chamber; wherein, The accelerating chamber is funnel-shaped, comprising a converging section and a diverging section, the cross-sectional area of the converging section gradually decreases along the material flow direction, and the cross-sectional area of the diverging section gradually increases along the material flow direction; The converging section is communicated with a positive pressure airflow pipe, the outlet of the positive pressure airflow pipe is directed to the diverging section, and the diverging section is communicated with a material conveying pipe; The accelerating chamber forms a local negative pressure area at the converging section, which is used to actively suck in the material and mix the material with the airflow to form a material-air two-phase flow.

2. The positive pressure air lock according to claim 1, wherein, The inlet of the positive pressure airflow pipe is located at the side of the accelerating chamber, and the outlet of the positive pressure airflow pipe forms a preset included angle with the material flow direction.

3. The positive pressure air lock according to claim 1, wherein, The connection between the converging section and the diverging section is a throat section, the cross-sectional area of the throat section is the minimum cross-sectional area of the accelerating chamber, which is used to concentrate the airflow velocity and enhance the local negative pressure effect.

4. The positive pressure air lock according to claim 3, wherein, The cross-sectional area and length of the throat section can be adjusted.

5. The positive pressure air lock according to claim 1, wherein, The outlet of the diverging section or the position communicated with the material conveying pipe is provided with a flow guide plate.

6. The positive pressure gate keeper of claim 1, wherein, The length ratio of the converging section to the diverging section ranges from 1:1.5 to 1:

3.

7. The positive pressure air lock according to claim 1, wherein, The outlet direction of the accelerating chamber is vertically downward or horizontally.

8. The positive pressure air lock according to claim 1, wherein, The feeding chamber comprises a shell, an end cover located on the shell, and a rotor located in the shell, the rotor is used to convey the material to the accelerating chamber.

9. The positive pressure air lock according to claim 8, wherein, The blade surface of the rotor adopts an arc structure or a streamline structure.

10. The positive pressure air lock according to claim 8, wherein, The inner wall of the shell is provided with a wear-resistant coating.

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