Rectification type air duct structure and fan set

Abstract

The utility model discloses a rectification type air duct structure and a fan set. The rectification type air duct structure comprises a centrifugal fan volute and a transition connector. A volute opening of the centrifugal fan volute is rectangular, the transition connector comprises a rectangular transition section and a circular flaring section, the rectangular transition section and the volute opening coaxially extend, the section of the rectangular transition section is consistent with the volute opening, and the inner section of the tail end of the circular flaring section is a circumcircle of the volute opening. The circular flaring section is provided with a transition runner extending to the rectangular transition section, and the transition runner comprises a rectification surface located on the long side and a guide surface located on the wide side; the rectifying face inclines from the end face of the circumcircle to the center, and the intersecting line of the rectifying face and the longitudinal axis plane of any transition connector is in a parabola shape. The guide face inclines from the end face of the circumcircle to the center, and the intersecting line of the guide face and the longitudinal axis plane of any transition connector is in an oblique line shape. The utility model has the advantages that airflow can be guided to smoothly transit from a rectangular section to a circular section, and turbulent flow and vortex are reduced, so that wind resistance and noise are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of fans, and particularly relates to a rectifying air duct structure and a fan group. Background Art

[0002] With the continuous upgrading of modern kitchen facilities, as the core component of the kitchen exhaust system, the performance of the fume exhaust fan directly affects the air quality and working efficiency of the kitchen environment. Traditional fume exhaust fans mostly adopt the design of centrifugal fans, and their working principle is to generate centrifugal force through a high-speed rotating impeller to extract and discharge fumes from the kitchen interior. However, there are some problems to be solved urgently in the design and application of centrifugal fans.

[0003] The volute of a centrifugal fan usually has a flat structure, which helps to reduce the volume of the fan and makes it easier to install in a limited space. However, the flat volute results in a rectangular structure at its air outlet, while the outlet pipe connected to the fan is often circular. This shape difference causes a transition problem between the two.

[0004] [[ID=I4]]As disclosed in patent CN114483653A, the "main body of the volute" refers to the part of the volute corresponding to the impeller 20 after the impeller 20 is placed in the volute, and the part where the volute shroud 500 is bent to form a shape adapted to the impeller 20. Correspondingly, the shapes of the upper volute plate 300 and the bottom volute plate 400 in this part are also adapted to the volute shroud 500. When the air flow at the outlet of the blade passage of the impeller 20 sweeps near the volute tongue 100, the volute tongue 100 will shunt the air flow, and most of the air flow flows along the passage to the air outlet 200. It can be seen from the attached drawings of the patent that a transition interface is provided at the air outlet 200 to connect the volute body and the pipe.

[0005] With the continuous optimization of the utilization of equipment space, modern fan volutes are designed to be more flat, and the aspect ratio of the air outlet also increases accordingly, forming a rectangular air outlet. Although this design saves space to a certain extent, it also brings a series of problems. Due to the large distance between the long side and the circumscribed circle, this design is prone to an increase in turbulence and eddy current at the corners. The increase in turbulence and eddy current will not only increase the wind resistance, reduce the efficiency of the fan, but also generate relatively large noise, affecting the working environment of kitchen staff.

[0006] In addition, the existence of turbulence and eddy current will also affect the fume emission effect. Under the action of turbulence, fume particles may collide and condense inside the fan, resulting in incomplete fume emission, and even may flow back into the kitchen interior, causing secondary pollution. This is obviously unacceptable for modern kitchens that pursue high efficiency and environmental protection. Content of the Utility Model

[0007] The technical problem to be solved by the present utility model is to provide a rectifying air duct structure and a fan unit that are more conducive to the air flow in the flat volute to flow into the circular duct.

[0008] The core concept of the present utility model is to provide a transition interface at the outlet of the rectangular volute, and a rectifying air duct is arranged inside the transition interface, so as to reduce the vortex and turbulence phenomena caused by the change of the cross-sectional shape.

[0009] The technical solution adopted by the present utility model to solve the above technical problem is: a rectifying air duct structure, including a centrifugal fan volute and a transition interface;

[0010] The centrifugal fan volute includes a bottom plate, a surrounding plate and a top plate. The bottom plate, the surrounding plate and the top plate enclose to form a volute air duct and a volute opening; the volute opening is rectangular, and the ends of the bottom plate and the top plate are the long sides of the volute opening, and the two ends of the curved surrounding plate are the wide sides of the volute opening, and the long side is more than twice the wide side;

[0011] The transition interface includes a rectangular transition section extending coaxially with the volute opening and a circular flaring section. The cross-section of the rectangular transition section is the same as that of the volute opening, and the inner cross-section at the end of the circular flaring section is the circumcircle of the volute opening;

[0012] The circular flaring section is provided with a transition flow channel extending to the rectangular transition section. The transition flow channel includes a rectifying surface on the long side and a guiding surface on the wide side;

[0013] The rectifying surface is inclined from the end face of the circumcircle to the center, and the intersection line with any longitudinal axis plane of the transition interface is parabolic; the guiding surface is inclined from the end face of the circumcircle to the center, and the intersection line with any longitudinal axis plane of the transition interface is oblique.

[0014] The preferred technical solution adopted by the present utility model to solve the above technical problem is: the rectifying surface and the long side plane of the corresponding rectangular transition section are transitioned through a curved surface, and the projection of the inner contour line of the curved surface on the longitudinal axis plane is parabolic.

[0015] The preferred technical solution adopted by the present utility model to solve the above technical problem is: the rectifying surface and the guiding surface are transitioned through an abutting surface.

[0016] The preferred technical solution adopted by the present utility model to solve the above technical problem is: the periphery of the volute opening includes a first annular docking wall, and the first annular docking wall is at a certain distance from the end of the volute opening to form an extension wall outside the first annular docking wall, and the first annular docking wall and the extension wall are at a right angle.

[0017] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: the second annular docking wall is provided on the periphery of the docking end of the rectangular transition section, the extension wall is inserted into the rectangular transition section, and the second annular docking wall and the first annular docking wall are abutted against each other and connected to each other by fasteners.

[0018] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: the inner wall of the docking end includes an annular depression matching the extension wall; the extension wall is fitted with the annular depression so that the inner wall is continuous after the centrifugal fan volute and the transition interface are docked.

[0019] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: the rectangular transition section is provided with a reinforcing section with an increasing wall thickness extending backward from the root of the second annular docking wall, and a plurality of triangular support walls are provided between the second annular docking wall and the reinforcing section.

[0020] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: the end of the circular flaring section is provided with an annular clamping portion, the annular clamping portion includes an inner annular wall and an outer annular wall, and an annular insertion groove for inserting a circular pipe is formed by an interval between the inner annular wall and the outer annular wall.

[0021] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: the inner annular wall includes a plurality of arc-shaped petal walls spaced apart from each other and surrounding an circumcircle.

[0022] The preferred technical solution adopted by the present utility model to solve the above technical problems is as follows: a fan group, which is used in an oil fume removal device, includes the rectifying air duct structure as described above, a wind wheel and a motor.

[0023] Compared with the prior art, the advantages of the present utility model are as follows: the parabolic-shaped rectifying surface can effectively and reasonably transition the long distance between the long side and the edge of the circumcircle, reduce the resistance and vortex generated during the air flow, thereby improving the air flow transmission efficiency. At the same time, the parabolic shape design can optimize the air flow velocity distribution and pressure distribution, reduce the air flow instability and turbulence phenomenon, lower the noise and reduce the wind loss. The distance between the short side and the edge of the circumcircle is short, and only an inclined guiding surface is needed between the two to effectively guide the air flow so that it flows in a smooth and continuous manner. Through the setting of the rectifying surface and the guiding surface, it helps to guide the air flow to smoothly transition from the rectangular cross-section to the circular cross-section, reduce the turbulence and vortex, thereby reducing the wind resistance and noise. Description of the Drawings

[0024] The present utility model will be further described in detail below in conjunction with the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are only drawn for the purpose of explaining the preferred embodiments and should not be construed as limiting the scope of the present utility model. In addition, unless otherwise specified, the drawings only schematically show the composition or structure of the described object and may include exaggerated displays, and the drawings are not necessarily drawn to scale.

[0025] Figure 1 Schematic diagram of a fan unit with a rectifying air duct structure;

[0026] Figure 2 For the disassembly of a fan unit with a rectifying air duct structure Figure 1 ;

[0027] Figure 3 For the disassembly of a fan unit with a rectifying air duct structure Figure 2 ;

[0028] Figure 4 Schematic diagram of a simplified cross-section of a rectifying air duct structure;

[0029] Figure 5 Schematic diagram of the principle of a rectifying air duct structure Figure 1 ;

[0030] Figure 6 Schematic diagram of the principle of a rectifying air duct structure Figure 2 . Detailed implementation manners

[0031] The preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are only descriptive and exemplary and should not be construed as limiting the protection scope of the present utility model.

[0032] It should be noted that: Similar reference numerals represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it will not be further defined and explained in subsequent drawings.

[0033] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present utility model is habitually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. The terms "first" and "second" are only for descriptive convenience and have no other directional meaning, and should not be construed as a limitation to the present utility model.

[0034] In this embodiment, as Figure 1 shown, we provide a novel rectifying air duct structure for the centrifugal fan in the kitchen oil fume exhaust system, enabling the centrifugal fan to be connected to the oil fume duct in a more reasonable manner. This structure consists of two parts: the centrifugal fan volute 1 and the transition interface 2, aiming to improve the exhaust efficiency, reduce the wind resistance and noise.

[0035] As Figure 1 、 5 shown, the centrifugal fan volute 1 is formed by enclosing a bottom plate 11, a side plate 12 and a top plate, forming a rectangular volute opening K. Among them, the ends of the bottom plate 11 and the top plate form the long sides, and the two ends of the curved side plate 12 form the wide sides. The length of the long side is twice that of the wide side. Such a design makes the centrifugal fan more flat, can reduce its occupied space in the equipment, and makes the equipment structure more compact. However, such a volute opening K structure also increases the difficulty of connecting to the circular oil fume duct. Therefore, in this embodiment, a transition interface 2 is provided at the volute outlet end to solve the air duct transition problem.

[0036] As Figure 1-3 、5-6 shown, the transition interface 2 includes a rectangular transition section 21 extending coaxially with the volute opening K and a circular flaring section 22. The cross-section of the rectangular transition section 21 is the same as that of the volute opening K, and the inner cross-section at the end of the circular flaring section 22 is the circumscribed circle H of the volute opening K. The circular flaring section 22 is provided with a transition flow channel extending to the rectangular transition section 21. The transition flow channel includes a rectifying surface A1 on the long side and a guiding surface A2 on the wide side. The rectifying surface A1 inclines from the end face of the circumscribed circle towards the center, and the intersection line with any longitudinal axis plane of the transition interface 2 is parabolic. The guiding surface A2 inclines from the end face of the circumscribed circle towards the center, and the intersection line with any longitudinal axis plane of the transition interface 2 is oblique.

[0037] The parabolic-shaped fairing surface A1 can effectively and reasonably transition the long distance between the long side and the edge of the circumscribed circle, reducing the resistance and vortices generated during the airflow, thereby improving the efficiency of airflow transmission. At the same time, the parabolic shape design can optimize the velocity distribution and pressure distribution of the airflow, reduce the instability and turbulence of the airflow, lower the noise, and reduce the wind loss. The distance between the short side and the edge of the circumscribed circle is short, and only an inclined guiding surface A2 is needed between the two to effectively guide the airflow to flow in a smooth and continuous manner. Through the settings of the fairing surface A1 and the guiding surface A2, it helps to smoothly guide the airflow from the rectangular cross-section to the circular cross-section, reducing turbulence and eddy currents, thereby reducing wind resistance and noise.

[0038] As Figure 1-3 shown, the fairing surface A1 and the long side plane of the corresponding rectangular transition section 21 are transitioned through a curved surface, and the projection of the inner contour line of the curved surface on the longitudinal axis plane is parabolic. The fairing surface A1 and the guiding surface A2 are transitioned through an abutting surface. This design makes the transition between surfaces smoother, can reduce the friction of the pipe wall surface, helps to reduce the flow resistance of the fluid in the air duct, and further helps to improve the stability of the airflow.

[0039] As Figure 2-4 shown, since the volute is generally processed by sheet metal, and the special-shaped transition interface 2 is processed by aluminum die-casting, a detachable docking method is set for connection between the two. To further improve the stability and sealing performance of the structure, as shown in the figure, the periphery of the volute port K includes a first annular docking wall m. The first annular docking wall m is at a certain distance from the end of the volute port K, and an extension wall s is formed outside the first annular docking wall m. The first annular docking wall m and the extension wall s are at a right angle. The docking end of the rectangular transition section 21 is provided with a second annular docking wall n, which abuts against the first annular docking wall m and is connected by fasteners.

[0040] As Figure 4 shown, the inner wall of the docking end of the rectangular transition section 21 includes an annular depression t that matches the extension wall s; the extension wall s is fitted into the annular depression t so that the inner wall is continuous after the centrifugal fan volute 1 and the transition interface 2 are docked. This not only makes the flow channel smoother, avoids the phenomenon of corner air stagnation caused by unevenness, reduces turbulence and eddy currents, but also improves the airtightness of the air duct, avoids air leakage, and at the same time enhances the dynamic balance of the fan and the transition interface 2, reducing the additional vibration and noise caused by imbalance.

[0041] As Figure 2-4 shown, in the rectangular transition section 21, there is also a reinforced section p with an increased wall thickness extending backward from the root of the second annular docking wall n, and several triangular support walls y are provided between the second annular docking wall n and the reinforced section p to enhance the stability and pressure resistance of the structure, suitable for high wind pressure environments.

[0042] As Figure 2-3 shown, an annular clamping portion G is provided at the end of the circular flared section 22, including an inner annular wall G1 and an outer annular wall G2. An annular insertion groove F for inserting a circular pipe is formed by an interval between the inner annular wall G1 and the outer annular wall G2, which is convenient for installation and maintenance.

[0043] As Figure 1-3 shown, the inner annular wall G1 includes a plurality of arc-shaped flap walls g that are spaced apart from each other and surround an circumcircle. The groove diameter of the annular insertion groove F can be adjusted by the deformation of the arc-shaped flap walls g, so as to clamp the circular pipe, enhancing the firmness and airtightness of the connection between the two.

[0044] As Figure 1 shown, this rectifying air duct structure is integrated with the wind wheel 3 and the motor 4 to form a complete fan unit, which is used in the fume removal equipment. This design not only improves the smoke exhaust efficiency, reduces the wind resistance and noise, but also enhances the structural stability and the convenience of installation and maintenance, and is applicable to various specifications of fume removal equipment, having good versatility and adaptability.

[0045] An introduction is made to a rectifying air duct structure and a fan unit provided by the present utility model. Specific examples are used in this article to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the present utility model and its core idea. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can still be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. A rectifying air duct structure, characterized in that It includes a centrifugal fan volute and a transition interface; The centrifugal fan volute includes a bottom plate, a surrounding plate and a top plate. The bottom plate, the surrounding plate and the top plate enclose to form a volute air duct and a volute opening. The volute opening is rectangular, and the ends of the bottom plate and the top plate are the long sides of the volute opening, and the two ends of the curved surrounding plate are the wide sides of the volute opening. The long side is more than twice the width of the wide side; The transition interface includes a rectangular transition section extending coaxially with the volute opening and a circular flaring section. The cross-section of the rectangular transition section is the same as that of the volute opening, and the inner cross-section at the end of the circular flaring section is the circumcircle of the volute opening. The circular flaring section is provided with a transition flow channel extending to the rectangular transition section. The transition flow channel includes a rectifying surface on the long side and a guiding surface on the wide side; The rectifying surface is inclined from the end face of the circumcircle to the center, and the intersection line with any longitudinal axis plane of the transition interface is parabolic; the guiding surface is inclined from the end face of the circumcircle to the center, and the intersection line with any longitudinal axis plane of the transition interface is oblique.

2. The rectifying air duct structure according to claim 1, characterized in that The rectifying surface and the long side plane of the corresponding rectangular transition section are transitioned through a curved surface. The projection of the inner contour line of the curved surface on the longitudinal axis plane is parabolic.

3. The rectifying air duct structure according to claim 1, characterized in that The rectifying surface and the guiding surface are transitioned through an abutting surface.

4. The rectifier air duct structure according to claim 1, wherein The periphery of the volute opening includes a first annular docking wall. The first annular docking wall is at a certain distance from the end of the volute opening, and an extending wall is formed outside the first annular docking wall. The first annular docking wall and the extending wall are at a right angle.

5. The rectifying air duct structure according to claim 4, characterized in that The periphery of the docking end of the rectangular transition section is provided with a second annular docking wall. The extending wall is inserted into the rectangular transition section. The second annular docking wall and the first annular docking wall abut against each other and are connected to each other by fasteners.

6. The rectifying air duct structure according to claim 5, characterized in that The inner wall of the docking end includes an annular depression matching the extending wall. The extending wall and the annular depression are fitted to make the inner wall continuous after the centrifugal fan volute and the transition interface are docked.

7. The rectifying air duct structure according to claim 6, characterized in that The rectangular transition section is provided with a reinforced section with an increased wall thickness extending backward from the root of the second annular docking wall. Several triangular support walls are provided between the second annular docking wall and the reinforced section.

8. The rectifying air duct structure according to claim 4, characterized in that The end of the circular flaring section is provided with an annular clamping portion. The annular clamping portion includes an inner annular wall and an outer annular wall. An annular insertion slot for inserting a circular pipe is formed between the inner annular wall and the outer annular wall at intervals.

9. The rectifying air duct structure according to claim 8, characterized in that The inner annular wall includes several arc-shaped flap walls spaced apart from each other to form a circumcircle.

10. A wind turbine unit, used in an oil fume removal device, characterized in that It includes a rectifying air duct structure as described in any one of claims 1-9, a wind wheel and a motor.

Images