Air knife mechanism and air throwing device

Abstract

The utility model relates to a threshing winnowing technology field, specifically disclose air knife mechanism and air throwing device. The mechanism includes air knife casing, air inlet unit and guide plate, air knife casing surrounds the airflow cavity, and the length direction of air knife casing has opposite air inlet end and air outlet end, and the air outlet end is equipped with the elastic plate and rigid plate that are parallel to each other, and the elastic plate and rigid plate form the air outlet channel, a plurality of elastic components are uniformly distributed in the width direction of air knife casing at intervals, and the elastic plate can produce the local deformation towards rigid plate under the impetus of elastic component, the air inlet unit includes air inlet pipe and air valve, and the air valve is used for adjusting the gas flow rate in air inlet pipe, the guide plate includes straight plate and arc plate, the straight plate is used for guiding the gas that discharges from the air outlet channel to flow above the straight plate, and the arc plate gradually bends upwards in the direction from the end of arc plate close to straight plate to the end of arc plate away from straight plate. The mechanism solves the problem of uneven wind through the optimization design of specific structure, and improves the wind separation precision.

Description

Technical Field

[0001] This utility model relates to the field of leaf-splitting and air-separation technology, and in particular to air knife mechanism and air-throwing device. Background Technology

[0002] In the leaf threshing and re-drying process, the pneumatic separation machine is a key piece of equipment used for the pneumatic separation of materials (including tobacco leaves, stems, and incompletely torn tobacco stems) after being threshed by the leaf threshing machine. Its working principle is as follows: a high-pressure pneumatic system throws the mixture into a wind field with a stable upward suction. Utilizing the density differences between tobacco leaves, stems, and incompletely torn tobacco stems, they drift and separate in a multiphase fluid. By adjusting the wind speed, the heavier stems and incompletely torn tobacco leaves settle, while the lighter tobacco leaves float with the wind. Finally, the tobacco leaves and stems are effectively separated by a material separation device such as a feeder. Materials that are not fully separated are then fed into the next stage of the pneumatic separation chamber for multiple separations to improve overall separation efficiency.

[0003] Traditional pneumatic blasting systems typically use a single high-pressure blower as the power source. An air distributor divides the airflow from the inlet into multiple paths, supplying each path to the air knife structure to achieve the blasting effect on the material. To adapt to fluctuations in material flow and changes in tobacco leaf type, high-pressure pneumatic blasting systems often employ variable frequency control to adjust the air speed. Simultaneously, the throwing angle of the air knives is designed to be adjustable, aiming to ensure the tobacco leaves are dispersed as evenly as possible within the air separation chamber, achieving optimal air separation. The air classifier fan also uses variable frequency speed control to meet the needs of different operating conditions.

[0004] However, this traditional structure has significant drawbacks in practical applications. Because the air knife uses a single-sided fan for air supply and distributes the airflow to multiple ducts along its width via a distributor, the airflow distribution along the length of the air knife is uneven. Due to the characteristics of pneumatic conveying, the wind speed is higher near the fan and significantly lower at the far end, even resulting in areas with no or weak wind. This uneven airflow directly affects the uniformity of material distribution in the air separation chamber, causing material accumulation and insufficient dispersion in some areas, thus impacting the final air separation accuracy and sheet yield. Although frequency conversion of the fan and adjustment of the throwing angle can alleviate this problem to some extent, they cannot fundamentally solve the technical bottleneck of uneven airflow along the width of the air knife. Utility Model Content

[0005] The purpose of this invention is to provide an air knife mechanism and an air-jetting device to solve the problem of uneven wind force and improve the accuracy of air separation.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] An air knife mechanism includes an air knife housing, an air inlet unit, and a guide plate. The air knife housing forms an airflow cavity and has opposing air inlet and outlet ends along its length. The outlet end is provided with a parallel elastic plate and a rigid plate, which form an air outlet channel that connects to the airflow cavity. A plurality of tensioning elements are evenly distributed along the width of the air knife housing. The elastic plate can undergo localized deformation towards the rigid plate under the pushing action of the tensioning elements. The air inlet unit is located at the air inlet end. The air intake unit includes an air intake pipe and an air valve movably connected to the air intake pipe. The air intake pipe is used to connect the airflow cavity and an external fan, and the air valve is used to regulate the gas flow rate in the air intake pipe. The guide plate includes a straight plate and an arc plate. The arc plate is fixed to the end of the straight plate away from the air knife housing. The straight plate is used to guide the gas discharged from the air outlet channel to flow above the straight plate. Along the direction from the end of the arc plate near the straight plate to the end of the arc plate away from the straight plate, the arc plate gradually bends upward.

[0008] As an optional technical solution for the air knife mechanism, the air valve includes a drive unit and a baffle. The baffle extends into the air inlet pipe, and the drive unit is used to drive the baffle to move radially along the air inlet pipe.

[0009] As an optional technical solution for the air knife mechanism, the length of the straight plate in the longitudinal direction of the air knife housing is 125 mm to 135 mm.

[0010] As an optional technical solution for the air knife mechanism, the inclination angle of the arc plate relative to the plane where the straight plate is located is 24° to 28°.

[0011] As an optional technical solution for the air knife mechanism, multiple air inlet units are provided, and all the air inlet units are evenly distributed at intervals along the width direction of the air knife housing at the air inlet end.

[0012] As an optional technical solution for the air knife mechanism, the tightening component includes a tightening bolt, which passes through the elastic plate and is screwed to the rigid plate, with the bolt head pressing against the elastic plate.

[0013] As an optional technical solution for the air knife mechanism, the elastic plate is made of spring steel.

[0014] As an optional technical solution for the air knife mechanism, the plane where the straight plate is located is parallel to the plane where the rigid plate is located.

[0015] The air-jetting device includes a blower, an air bag mechanism, and the aforementioned air knife mechanism. The output end of the blower is connected to the air inlet pipe. The air bag mechanism is located below the air knife mechanism and is used to provide airflow upwards.

[0016] As an optional technical solution for the air-jetting device, the air-jetting device also includes a device housing, in which the air bag mechanism and the air knife mechanism are both located. Both ends of the air knife housing in the width direction are fixed with air knife fixing plates, and the air knife fixing plates are detachably connected to the inner wall of the device housing.

[0017] The beneficial effects of this utility model are:

[0018] This air knife mechanism utilizes the airflow cavity enclosed by the air knife housing and the air outlet channel formed by the elastic and rigid plates at the outlet end. Combined with the adjustment of the elastic plate's local deformation by tensioning components, it achieves locally controllable adjustment of the air outlet channel gap along the width of the air knife housing. This adapts to different material flow rates and types, solving the problem of uneven airflow along the width of the air knife housing, resulting in a more uniform air velocity distribution, reduced turbulence, enhanced accuracy and adaptability of air separation, and improved air separation precision. The air valve in the air inlet unit can adjust the gas flow rate within the air inlet pipe. By changing the valve opening or controlling the fan frequency, fine adjustment of airflow and velocity is achieved, compensating for the shortcomings of relying solely on fan frequency conversion control. This allows the system to quickly adapt to changes in material flow rate and type, optimizing the air-jetting effect. The straight and curved design of the guide plate allows the air jetting air to flow upward along the curved plate after being discharged from the air outlet channel. The air jetting air can also blow the material falling on the guide plate to move together, reducing the interference of the air separation air from below on the air jetting air, optimizing the material's throwing trajectory and angle, making it easier to find the optimal initial air separation velocity, achieving full and uniform dispersion of the material, and thus accurately separating the useful blades, thereby improving the blade output rate.

[0019] This air-jetting device integrates a fan, air bag mechanism, and air knife mechanism. Through coordinated operation, it achieves smooth merging of air for jetting and air for separation. The device solves the problems of uneven airflow and interference with air separation, adapting to different material flow rates and types. It significantly improves the separation efficiency and yield of tobacco sheets and stems, enhancing overall air separation accuracy and stability. Furthermore, it adapts to variations in material flow rates and types, improving production efficiency and product quality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the air knife mechanism provided in this embodiment of the utility model;

[0021] Figure 2 This is a side view of the air knife mechanism provided in this embodiment of the utility model.

[0022] In the picture:

[0023] 1. Air valve; 2. Air inlet pipe; 3. Air knife housing; 31. Elastic plate; 32. Rigid plate; 4. Air outlet channel; 5. Material guide plate; 51. Straight plate; 52. Curved plate; 6. Air knife fixing plate. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. 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.

[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0028] like Figure 1 and Figure 2 As shown, this utility model provides an air-jetting device, including a blower, an air bag mechanism and an air knife mechanism. The output end of the blower is connected to the air inlet pipe 2. The air bag mechanism is located below the air knife mechanism and is used to provide airflow upward.

[0029] In this embodiment, the airflow provided by the airbag mechanism is defined as air distribution air, and the airflow discharged from the airflow chamber is defined as air throwing air. Taking tobacco as an example, tobacco includes tobacco leaves and tobacco stems.

[0030] This air-jetting device integrates a fan, air bag mechanism, and air knife mechanism. Through coordinated operation, it achieves smooth merging of air for jetting and air for separation. The device solves the problems of uneven airflow and interference with air separation, adapting to different material flow rates and types. It significantly improves the separation efficiency and yield of tobacco sheets and stems, enhancing overall air separation accuracy and stability. Furthermore, it adapts to variations in material flow rates and types, improving production efficiency and product quality.

[0031] For example, the air-blasting device is a leaf-beating and re-drying air-blasting device.

[0032] In this embodiment, the air-jet device also includes a device housing, and the air bag mechanism and the air knife mechanism are both located inside the device housing. Both ends of the air knife housing 3 in the width direction are fixed with air knife fixing plates 6, and the air knife fixing plates 6 are detachably connected to the inner wall of the device housing.

[0033] The outer casing protects the internal structure from external interference. The detachable air knife mounting plate 6 facilitates quick maintenance, replacement, or adjustment of the air knife mechanism, improving the modularity and maintainability of the air blasting device. This facilitates installation, maintenance, and adjustment, ensuring the air knife mechanism maintains optimal operating condition during air separation, reducing the impact of vibration and displacement on air separation efficiency, improving equipment reliability and ease of operation, and lowering maintenance costs. Simultaneously, this design reduces downtime, enhances the equipment's applicability and durability, and makes it suitable for continuous production environments.

[0034] In this embodiment, the air-jetting device also includes a conveyor belt for inputting and scattering materials. The concentrated area where the materials scattered by the conveyor belt fall is defined as the material drop area. By adjusting the relative position of the conveyor belt and the air knife mechanism, the transition position between the straight plate 51 and the arc plate 52 is moved to the material drop area.

[0035] This utility model also provides an air knife mechanism, which is applied to the aforementioned air-jetting device. The air knife mechanism includes an air knife housing 3, an air inlet unit, and a guide plate 5. The air knife housing 3 forms an airflow cavity, and has opposing air inlet and outlet ends along its length. The outlet end is provided with a parallel elastic plate 31 and a rigid plate 32, which form an air outlet channel 4 that connects to the airflow cavity. Several tensioning elements are evenly distributed along the width of the air knife housing 3, and the elastic plate 31 can be pushed by the tensioning elements to generate a local force towards the rigid plate 32. Deformation; The air inlet unit is located at the air inlet end. The air inlet unit includes an air inlet pipe 2 and an air valve 1 movably connected to the air inlet pipe 2. The air inlet pipe 2 is used to connect the airflow cavity and the external fan. The air valve 1 is used to adjust the gas flow rate in the air inlet pipe 2. The guide plate 5 includes a straight plate 51 and an arc plate 52. The arc plate 52 is fixed to the end of the straight plate 51 away from the air knife housing 3. The straight plate 51 is used to guide the gas discharged from the air outlet channel 4 to flow above the straight plate 51. Along the direction from the end of the arc plate 52 close to the straight plate 51 to the end of the arc plate 52 away from the straight plate 51, the arc plate 52 gradually bends upward.

[0036] This air knife mechanism utilizes the airflow cavity enclosed by the air knife housing 3 and the air outlet channel 4 formed by the elastic plate 31 and rigid plate 32 at the air outlet end. Combined with the local deformation adjustment of the elastic plate 31 by the tensioning components, it achieves locally controllable adjustment of the gap in the air outlet channel 4 along the width direction of the air knife housing 3. This adapts to different material flow rates and types, solving the problem of uneven airflow along the width direction of the air knife housing 3, resulting in a more uniform air velocity distribution, reduced turbulence, enhanced accuracy and adaptability of air separation, and improved air separation precision. The air valve 1 in the air inlet unit can adjust the gas flow rate within the air inlet pipe 2. By changing the opening of the air valve 1 or controlling the fan frequency, fine adjustment of the air volume and speed is achieved, compensating for the shortcomings of relying solely on fan frequency conversion control. This allows the system to quickly adapt to changes in material flow rate and type, optimizing the air-throwing effect. The design of the straight plate 51 and the arc plate 52 of the guide plate 5 allows the air jetting air to flow upward along the arc plate 52 after being discharged from the air outlet channel 4. The air jetting air can also blow the material falling on the guide plate 5 to move together, reducing the interference of the air separation air from below on the air jetting air, optimizing the trajectory and angle of the material, making it easier to find the optimal initial velocity of the air separation, achieving full and uniform dispersion of the material, and thus accurately separating the useful blades, thereby improving the blade output rate.

[0037] In this embodiment, the air valve 1 includes a drive unit and a baffle. The baffle extends into the air inlet pipe 2, and the drive unit is used to drive the baffle to move radially along the air inlet pipe 2.

[0038] The drive unit and baffle design of the air valve 1 allow the drive unit to precisely control the radial movement of the baffle in the air inlet duct 2, simplifying the operation process, quickly adjusting air resistance, and more precisely balancing the air velocity in the width direction of the air knife housing 3, thus improving air separation consistency. This enhances the system's ability to respond to changes in material flow rate, making air volume control more flexible and capable of efficiently matching different levels of control requirements. It compensates for the shortcomings of relying solely on fan frequency control, making air volume adjustment more efficient and faster, adapting to different material grades and flow rate changes, and further improving air separation accuracy and ease of operation.

[0039] For example, the length of the straight plate 51 in the longitudinal direction of the air knife housing 3 is 125 mm to 135 mm. Specifically, the length of the straight plate 51 in the longitudinal direction of the air knife housing 3 is 130 mm.

[0040] By limiting the length of the straight plate 51, the material is effectively guided in the dropping area, reducing the obstruction of the air distribution air by the guide plate 5. This allows the air jetting air to be more concentrated and thrown upwards, and the air jetting air to merge more smoothly with the air distribution air. This optimizes the airflow path, reduces turbulence, improves the separation accuracy and efficiency of tobacco sheets and stems, facilitates finding the optimal initial air separation velocity, and ensures that the material is thrown up at an ideal angle in the dropping area.

[0041] In this embodiment, the inclination angle of the arc plate 52 relative to the plane containing the straight plate 51 is 24° to 28°. Specifically, the inclination angle of the arc plate 52 relative to the plane containing the straight plate 51 is 26°.

[0042] By limiting the tilt angle of the arc plate 52 relative to the straight plate 51, the material is ensured to be thrown upwards at an ideal angle, forming the optimal confluence angle with the air separation air. This helps control the initial velocity of the air separation, reduces mutual interference, allows the material to fully diffuse within the air separation chamber, reduces the mutual influence between the air throwing air and the air separation air, improves air classification efficiency, and increases the separation accuracy of tobacco sheets and stems, thereby increasing the sheet yield.

[0043] For example, multiple air inlet units are provided, and all air inlet units are evenly distributed at the air inlet end along the width direction of the air knife housing 3.

[0044] Multiple air inlet units are evenly distributed along the width of the air knife housing, allowing airflow to enter the airflow chamber uniformly from multiple points. The airflow in different areas can be adjusted separately, effectively regulating the uniformity of airflow and velocity distribution in the air-jetting process. This solves the problem of uneven airflow, further ensuring the uniformity and stability of airflow in the width direction, eliminating windless or weak airflow areas, and making the entire air separation process more stable. This design enhances the stability and consistency of the air separation process, making it suitable for variable control in large-scale production and improving overall air separation accuracy.

[0045] In this embodiment, the tightening component includes a tightening bolt, which passes through the elastic plate 31 and is screwed to the rigid plate 32. The head of the tightening bolt presses against the elastic plate 31.

[0046] The tensioning element uses adjustable bolts, allowing for localized adjustment of the deformation of the elastic plate 31 by tightening or loosening, thereby precisely controlling the gap of the air outlet channel 4 and controlling the air volume and velocity. This achieves localized and precise control of the air velocity in the width direction of the air knife housing 3, adapting to the air separation needs of different materials, simplifying operation, and enabling rapid optimization of air velocity distribution. It helps improve the flexibility and adjustability of the air blasting device and reduces downtime for adjustment.

[0047] Furthermore, the elastic plate 31 is made of spring steel.

[0048] The elastic plate 31 is made of spring steel, which has good elasticity and durability. It can withstand repeated adjustments without easily fatigued or deformed, ensuring that the elastic plate 31 can maintain its shape and performance after repeated adjustments. This ensures the long-term stability and reliability of the air outlet duct 4 gap adjustment, extends the service life of the air knife mechanism, reduces maintenance needs, lowers long-term operating costs, and maintains air selection accuracy.

[0049] In this embodiment, the plane containing the straight plate 51 is parallel to the plane containing the rigid plate 32.

[0050] The plane of the straight plate 51 is parallel to the plane of the rigid plate 32, allowing the air jetting air to flow smoothly along the straight plate 51 after being discharged from the air outlet channel 4 and guided to the arc plate 52. This reduces airflow disturbance and energy loss, promotes the smooth merging of the air jetting air and the air separation air, and makes the air jetting air more stable, further optimizing the jetting effect and improving the air separation accuracy and efficiency. This optimizes the interaction between the airflow and the material, improves the air separation efficiency, and ensures the consistency of the throwing angle, further improving the separation accuracy, improving the air classification accuracy and efficiency, while simplifying the design of the air knife mechanism and facilitating manufacturing and installation.

[0051] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An air knife mechanism, characterized in that, include: The air knife housing (3) forms an airflow cavity. The air knife housing (3) has an air inlet end and an air outlet end in the length direction. The air outlet end is provided with a parallel elastic plate (31) and a rigid plate (32). The elastic plate (31) and the rigid plate (32) form an air outlet channel (4). The air outlet channel (4) connects to the airflow cavity. Several tensioning members are evenly distributed in the width direction of the air knife housing (3). The elastic plate (31) can generate local deformation toward the rigid plate (32) under the push of the tensioning members. An air intake unit is provided at the air intake end. The air intake unit includes an air intake pipe (2) and an air valve (1) movably connected to the air intake pipe (2). The air intake pipe (2) is used to connect the airflow cavity and an external fan. The air valve (1) is used to adjust the gas flow rate in the air intake pipe (2). The guide plate (5) includes a straight plate (51) and an arc plate (52). The arc plate (52) is fixed to the end of the straight plate (51) away from the air knife housing (3). The straight plate (51) is used to guide the gas discharged from the air outlet channel (4) to flow above the straight plate (51). Along the direction from the end of the arc plate (52) close to the straight plate (51) to the end of the arc plate (52) away from the straight plate (51), the arc plate (52) gradually bends upward.

2. The air knife mechanism according to claim 1, characterized in that, The air valve (1) includes a drive unit and a baffle. The baffle extends into the air inlet pipe (2). The drive unit is used to drive the baffle to move radially along the air inlet pipe (2).

3. The air knife mechanism according to claim 1, characterized in that, The length of the straight plate (51) in the longitudinal direction of the air knife housing (3) is 125 mm to 135 mm.

4. The air knife mechanism according to claim 1, characterized in that, The angle of inclination of the arc plate (52) relative to the plane on which the straight plate (51) is located is 24° to 28°.

5. The air knife mechanism according to claim 1, characterized in that, The air inlet unit is provided in multiple ways, and all the air inlet units are evenly distributed at the air inlet end along the width direction of the air knife housing (3).

6. The air knife mechanism according to claim 1, characterized in that, The fastening element includes a fastening bolt, which passes through the elastic plate (31) and is screwed to the rigid plate (32), with the bolt head pressing against the elastic plate (31).

7. The air knife mechanism according to claim 6, characterized in that, The elastic plate (31) is made of spring steel.

8. The air knife mechanism according to any one of claims 1-7, characterized in that, The plane containing the straight plate (51) is parallel to the plane containing the rigid plate (32).

9. A pneumatic projectile device, characterized in that, It includes a fan, an air bag mechanism, and an air knife mechanism as described in any one of claims 1-8, wherein the output end of the fan is connected to the air inlet pipe (2), the air bag mechanism is located below the air knife mechanism, and the air bag mechanism is used to provide airflow upward.

10. The pneumatic throwing device according to claim 9, characterized in that, The air-jetting device also includes a device housing. The air bag mechanism and the air knife mechanism are both located inside the device housing. Both ends of the air knife housing (3) in the width direction are fixed with air knife fixing plates (6). The air knife fixing plates (6) are detachably connected to the inner wall of the device housing.

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