A coaxial reverse double-cyclone oil fume separator

Abstract

The application discloses a kind of coaxial reverse double spin net oil fume separators, including smoke guide ring, coaxial motor and the first separating net and the second separating net being arranged along the axial direction interval of smoke guide ring.Coaxial motor includes the first motor and the second motor of coinciding rotation axis, the drive shaft of second motor is connected with being passed in the first motor, the first separating net is driven by the first motor, the second separating net is driven by the second motor by drive shaft, two separating nets rotate in opposite directions, so that oil fume sequentially passes through two dynamic separating areas of opposite rotation.The application can realize double-stage reverse dynamic oil fume separation and grading oil dirt isolation discharge, compact structure, can be set as independent oil fume pre-separation module in the smoke inlet end of oil fume treatment equipment.

Description

Technical Field

[0001] This invention relates to the technical field of oil fume separation and purification equipment, specifically to a coaxial reverse-rotating double-swirl screen oil fume separator. Background Technology

[0002] Cooking fumes typically consist of air, steam, liquid oil droplets, fine oil mist, and other suspended particles. When a range hood is operating, the rear fan creates negative pressure, drawing the fumes into the device through the inlet and expelling them through the fan impeller, volute, and exhaust pipes. If a large amount of oil droplets and oil mist enters the fan and volute without effective separation, they easily adhere to the fan impeller, the inner wall of the volute, and the exhaust channels, forming a thick layer of grease and increasing the frequency of cleaning and maintenance. Furthermore, long-term accumulation of grease on the impeller can affect its dynamic balance and aerodynamic performance. Therefore, existing range hoods usually have filters or other oil fume separation structures at the inlet to pre-separate oil droplets and oil mist before they enter the fan.

[0003] The most common existing oil fume separation structure is the static filter. When oil fumes pass through the static filter, oil droplets and oil mist are mainly trapped by the filter through inertial collision, contact adhesion, and agglomeration. Although this structure is simple, because the filter itself remains stationary, the relative motion between the filter filaments and the oil fumes mainly depends on the flow velocity of the oil fumes themselves. For oil mist particles with small particle sizes and strong airflow mobility, their trajectory may directly pass through the filter mesh without effectively colliding with the filaments. Therefore, the static filter's ability to capture fine oil mist is somewhat limited. To improve the relative motion velocity between the oil fumes and the filter, existing technologies have also developed rotary oil fume separation screens. These screens use a motor to drive the screen to rotate at high speed, causing the filaments to actively sweep across the oil fume channel. Oil droplets collide with the high-speed moving filaments, adhere, and agglomerate. Then, the centrifugal force generated by the rotation throws the oil to the outside. However, when using a single-layer rotary separation screen, the oil fumes usually only undergo one dynamic collision and centrifugal separation. Fine oil mist that is not captured during the first pass through the filaments may still continue to enter the subsequent fan with the airflow. If the separation performance is improved by simply increasing the wire density of the single-layer separation mesh or increasing its rotation speed, it is easy to lead to increased ventilation resistance, increased rotational load, and increased requirements for structural strength and noise control. Therefore, the space for further improving the separation capacity of the single-stage rotating separation structure is limited.

[0004] Simply adding a second filter layer to a single-layer rotating separator increases filtration opportunities, but if the second filter remains stationary, it remains primarily a passive interception structure. If both separators rotate in the same direction, the local airflow and remaining oil mist, after passing through the first-stage rotating separator, may experience tangential motion corresponding to the direction of rotation of that separator. When this continues into the second-stage rotating separator, the relative motion between the second separator and the remaining oil mist is limited. Therefore, simply superimposing or rotating two filters in the same direction does not fully utilize the synergistic effect between the two dynamic separation structures. Furthermore, using two independent, offset motors to drive the two rotating separators not only complicates the transmission structure but also occupies radial space in the smoke inlet channel, making it difficult to form a compact, centrally symmetrical modular unit. Furthermore, the oil captured by the high-speed rotating separation net is thrown in large quantities onto the inner wall of the smoke guide structure under centrifugal force. If there is a lack of oil isolation and drainage structures that match the front and rear rotating separation structures, the oil generated in the front stage separation may flow axially backward along the inner wall of the smoke guide structure and enter the subsequent separation area. The oil generated in the subsequent stage separation may then further flow along the inner wall of the smoke guide structure into the internal areas of the range hood, such as the fan and volute, thus weakening the oil isolation function of the front-stage oil fume separation device. Therefore, it is necessary to provide an oil fume separation device that can achieve independent counter-rotation of the two-stage separation nets within a compact structural space, and can also isolate, collect, and discharge the oil separated in the front and rear stages respectively. Summary of the Invention

[0005] The purpose of this invention is to address the problems of existing static filters having limited ability to capture fine oil mist, single-layer rotating filters only forming single-stage dynamic separation, insufficient synergistic separation effect when two-layer separation structures are simply superimposed, and the tendency of separated oil sludge to flow axially along the inner wall of the shell, by providing a coaxial reverse-rotating double-swirl oil fume separator.

[0006] To achieve the above objectives, the present invention provides a coaxial reverse-rotating double-swirl screen oil fume separator, including a smoke guide ring and a coaxial motor disposed at the center of the smoke guide ring. The smoke guide ring forms an oil fume channel for oil fumes to pass through. The coaxial motor includes a first motor and a second motor arranged sequentially along the axial direction, and the rotation axes of the first motor and the second motor coincide. The rotor of the second motor is connected to one end of the drive shaft, the drive shaft passes through the first motor along the rotation axis of the first motor, and the other end of the drive shaft extends out of the first motor; The fume duct is provided with a first separation net and a second separation net, which are spaced apart along the axial direction of the fume duct and are both located on the flow path of the fumes. The first separating mesh is connected to the rotor of the first motor, and the second separating mesh is connected to the other end of the drive shaft; The first motor and the second motor have opposite output rotation directions to drive the first separating net and the second separating net to rotate in opposite directions around the rotation axis, respectively.

[0007] Furthermore: the smoke guide ring is circular, and a plurality of connecting ribs extending toward its center are provided at one axial end of the smoke guide ring. The inner ends of the plurality of connecting ribs are connected to a motor base located at the center of the smoke guide ring, and the coaxial motor is mounted on the motor base.

[0008] Furthermore, the outer cover of the coaxial motor is provided with a sealing seat, which is sealed to the motor base and together forms a sealed cavity for accommodating the coaxial motor.

[0009] Furthermore, the stators of both the first motor and the second motor are mounted on a motor frame, which is fixedly positioned relative to the smoke guide ring.

[0010] Furthermore, one axial end of the smoke guide ring is provided with an oil-blocking flange extending toward the center of the smoke guide ring.

[0011] Furthermore, an inner oil drain hole is provided on the peripheral wall of the smoke guide ring, and the inner oil drain hole is located on the radial outer side of the oil-blocking flange.

[0012] Furthermore, an oil-blocking ring is provided on the inner peripheral wall of the smoke guide ring extending toward its center, and the oil-blocking ring is located between the first separation net and the second separation net along the axial direction of the smoke guide ring.

[0013] Furthermore, an external oil drain hole is provided on the peripheral wall of the smoke guide ring, and the external oil drain hole is located on the radial outer side of the oil baffle ring.

[0014] Furthermore, a honeycomb filter is detachably installed at the air inlet end of the smoke guide ring.

[0015] Furthermore, the outer periphery of the honeycomb filter is connected to the air guide ring, and the air guide ring is detachably connected to the air inlet end of the smoke guide ring.

[0016] Compared with the prior art, the present invention has the following technical effects.

[0017] 1. This invention does not merely increase the number of filter screens to improve oil fume separation capacity, but rather forms two continuous dynamic separation stages along the direction of oil fume flow: the second separation screen at the front end and the first separation screen at the rear end, with the two screens rotating in opposite directions. When the oil fume first passes through the second separation screen, oil droplets and oil mist dynamically collide, adhere, and coalesce with the high-speed moving mesh fibers, and the resulting oil liquid is thrown outwards under centrifugal force.

[0018] 2. The remaining oil mist that was not captured in the previous stage continues to move toward the first separation net, and the rotation of the second separation net will also cause circumferential disturbance to the local airflow passing through it, thus changing the motion state of the remaining oil mist.

[0019] 3. Since the first separation net rotates in the opposite direction to the second separation net, its mesh wires can form a dynamic sweep in a different direction for the remaining oil mist after the previous stage disturbance. This helps to increase the relative movement and collision opportunities between the subsequent separation net and the remaining oil mist, and reduces the possibility that the oil mist will continuously pass through the two separation stages along an approximate motion trajectory.

[0020] 4. The coaxial motor utilizes two motors with coincident rotating axes and a through-shaft power transmission structure to centrally arrange two independent and oppositely rotating outputs in the central area of ​​the smoke guide ring. This allows the two separation nets to work around the same rotating axis, improving the compactness and central symmetry of the structure while reducing the area occupied by the drive structure in the effective smoke inlet area. Furthermore, the oil baffle ring blocks the oil spilled by the second separation net at the front end within its corresponding pre-stage oil collection area and discharges it through the external oil drain hole, preventing the oil from continuing to flow axially into the area of ​​the first separation net at the rear.

[0021] 5. The oil-blocking flange blocks the oil that adheres to the inner wall of the smoke guide ring after the subsequent separation and continues to flow axially backward, allowing it to be discharged through the inner oil drain hole and preventing it from easily entering the interior of the range hood. Therefore, this invention not only forms a continuous two-stage reverse dynamic oil fume separation process, but also forms a relatively complete oil control path through an oil sludge classification isolation and discharge structure adapted to the two-stage separation. It is suitable as an independent pre-oil fume separation module installed at the smoke inlet of existing range hoods to reduce the oil load on the rear fan and volute and extend the cleaning and maintenance cycle. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention as viewed from the air inlet end.

[0023] Figure 2 This is a schematic diagram of the overall structure of the present invention when viewed from the other side.

[0024] Figure 3 This is a cross-sectional view of the structure of the present invention.

[0025] Figure 4 In this invention Figure 3 Enlarged view of the structure of part A.

[0026] Figure 5 This is an exploded view of the structure of the present invention.

[0027] Figure 6 This is a schematic diagram of the structure of the present invention after concealing the first separation mesh, the second separation mesh, and the honeycomb filter.

[0028] Figure 7 This is an assembly diagram of the coaxial motor and sealing seat of the present invention.

[0029] Figure 8 This is a schematic diagram of the coaxial motor structure of the present invention.

[0030] Figure label: 1. Smoke guide ring; 11. Connecting rib; 12. Motor base; 13. Oil baffle flange; 14. Inner oil drain hole; 15. Oil baffle ring; 16. Outer oil drain hole; 2. Coaxial motor; 21. First motor; 22. Second motor; 23. Drive shaft; 24. Motor frame; 25. Sealing seat; 26. Sealing cavity; 3. First separation network; 4. Second separation network; 5. Honeycomb filter; 6. Air guide ring. Detailed Implementation

[0031] The structure and working principle of the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments described below are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention. In order to facilitate the description of the relative positions of the components, the side where the honeycomb filter 5 is located is defined as the air inlet side, and the side where the oil fumes enter the rear range hood fan and volute after passing through this oil fume separator is defined as the air outlet side or rear end. The second separation net 4 is located at the front end position near the air inlet side, and the first separation net 3 is located behind the second separation net 4 along the direction of oil fume flow. The above-mentioned air inlet side, air outlet side, front end and rear end are only used to describe the relative positional relationship between the components and the direction of oil fume flow, and are not used to limit the spatial orientation of the present invention during actual installation.

[0032] like Figures 1 to 6 As shown, the coaxial reverse-rotating double-swirl screen oil fume separator in this embodiment mainly includes a smoke guide ring 1, a coaxial motor 2, a first separation screen 3, a second separation screen 4, a honeycomb filter 5, and a wind guide ring 6. The smoke guide ring 1 is generally circular, and an axially continuous oil fume channel is formed inside it. The second separation screen 4 and the first separation screen 3 are arranged alternately along the direction of oil fume flow and basically cover the main flow section of the oil fume channel, so that the oil fume entering the smoke guide ring 1 first passes through the second separation screen 4 located at the front end, and then passes through the first separation screen 3 located behind it.

[0033] The smoke guide ring 1 has several connecting ribs 11 extending from its periphery towards the center at one axial end. These connecting ribs 11 are spaced apart circumferentially along the smoke guide ring 1. The inner ends of the connecting ribs 11 are connected to the motor base 12 located at the center of the smoke guide ring 1. A flow area for oil fumes is formed between adjacent connecting ribs 11. Thus, the connecting ribs 11 can provide stable support for the motor base 12 and the coaxial motor 2 located in the central area, and can also reduce the obstruction of the oil fume channel by the central mounting structure, so that the coaxial motor 2 is located in the central area of ​​the smoke guide ring 1 and its rotation axis corresponds to the central axis of the smoke guide ring 1.

[0034] like Figure 8 As shown, the coaxial motor 2 includes a first motor 21 and a second motor 22 arranged sequentially along the axial direction of the smoke guide ring 1, with the rotation axes of the first motor 21 and the second motor 22 coinciding with each other. The first motor 21 and the second motor 22 each have an independently rotatable rotor, and their stators are mounted on a motor frame 24, which is fixedly positioned relative to the smoke guide ring 1. The rotor of the second motor 22 is connected to one end of a drive shaft 23, which extends along the rotation axis of the first motor 21 and passes through the first motor 21, with the other end of the drive shaft 23 extending out of the first motor 21.

[0035] The drive shaft 23 and the rotation output part of the first motor 21 can rotate relatively independently, thus forming two independent but coaxial power output paths. The first motor 21 drives the first separation net 3 to rotate, while the second motor 22 drives the second separation net 4 to rotate through the drive shaft 23.

[0036] In actual manufacturing, bearings, bushings, positioning structures and sealing structures can be set at the corresponding rotational connection positions according to the specific structure of the coaxial motor 2, so as to ensure that the drive shaft 23 rotates stably and maintains the required coaxiality between the first motor 21 and the second motor 22.

[0037] The coaxial motor 2 has a sealing seat 25 on its outer cover. The sealing seat 25 is sealed to the motor base 12 and together with the motor base 12 forms a sealed cavity 26. The main electrical and rotating components of the first motor 21 and the second motor 22 are located in the sealed cavity 26, thereby reducing the possibility of oil fumes and oil directly entering the motor and improving the working reliability of the coaxial motor 2 in the oil fume environment.

[0038] Both the first separating mesh 3 and the second separating mesh 4 can be configured as generally disc-shaped rotating separating structures, rotating around the common rotation axis of the coaxial motor 2. The second separating mesh 4 is positioned at the front end near the fume inlet side, while the first separating mesh 3 is positioned behind it. Therefore, during operation, the fumes first pass through the second separating mesh 4 and then the first separating mesh 3. The first separating mesh 3 is connected to the rotor of the first motor 21, and the second separating mesh 4 is connected to the end of the drive shaft 23 extending from the first motor 21. When the first motor 21 and the second motor 22 operate, they output rotational motions in opposite directions, causing the first separating mesh 3 and the second separating mesh 4 to rotate in opposite directions around the same rotation axis.

[0039] For example, viewed from the same axial direction, when the second separating net 4 rotates clockwise, the first separating net 3 rotates counterclockwise; alternatively, the second separating net 4 can rotate counterclockwise while the first separating net 3 rotates clockwise. This invention requires the two separating nets to have opposite rotational directions, but does not require them to have exactly the same rotational speed. Therefore, the first motor 21 and the second motor 22 can drive the two separating nets to rotate in opposite directions at the same absolute speed, or they can rotate at different speeds depending on the amount of oil fume, the equipment's operating level, and the structural parameters of the two separating nets. The first separating net 3 and the second separating net 4 may each include a central connecting part, several separating net strips distributed radially outward from the central area, and an annular reinforcing part for connecting or strengthening the separating net strips. A gap is formed between adjacent net strips to allow airflow. The number of net strips, the size of the gaps, the radial distribution pattern, and the materials of the two separating nets can be selected according to the oil fume flow rate, the target separation effect, and the rotational intensity.

[0040] The smoke guide ring 1 is also equipped with an oil contamination isolation and drainage structure that cooperates with the two rotating separation stages. The inner peripheral wall of the smoke guide ring 1 extends towards its center to form an oil baffle ring 15. The oil baffle ring 15 is located between the front second separation net 4 and the rear first separation net 3 along the direction of oil fume flow, and forms an annular oil contamination isolation structure on the inner periphery of the smoke guide ring 1. During the high-speed rotation of the second separation net 4, the oil that it captures and aggregates moves radially outward under centrifugal force and is thrown to the inner wall of the smoke guide ring 1. Without the oil baffle ring 15, this part of the oil contamination may continue to flow axially backward along the direction of oil fume flow after adhering to the inner wall of the smoke guide ring 1, and enter the area of ​​the rear first separation net 3.

[0041] The oil-blocking ring 15 extends from the inner peripheral wall of the smoke guide ring 1 towards the center, thereby blocking the oil flowing axially backward along the inner wall of the smoke guide ring 1. This confines the oil separated by the second separation net 4 to the preceding oil collection area corresponding to the second separation net 4 and the oil-blocking ring 15. The external oil discharge hole 16 on the peripheral wall of the smoke guide ring 1 corresponds to this preceding oil collection area. The oil blocked and collected by the oil-blocking ring 15 can be discharged from the smoke guide ring 1 through the external oil discharge hole 16, thereby reducing the possibility of preceding oil separation crossing the oil-blocking ring 15 axially and entering the working area of ​​the first separation net 3. Thus, the oil-blocking ring 15 not only serves to receive and assist in oil collection, but more importantly, it forms an oil separation boundary between the two rotating separation stages, allowing the oil separated from the airflow by the second separation net 4 to exit the subsequent oil fume separation channel as much as possible, preventing it from re-contaminating the following first separation net 3.

[0042] Behind the first separation mesh 3, an oil-blocking flange 13 extending towards the center of the smoke guide ring 1 is provided at one axial end, forming a second oil-stain isolation structure. The oil formed after further separation by the first separation mesh 3 is also thrown towards the inner wall of the smoke guide ring 1 under the centrifugal force generated by the high-speed rotation of the first separation mesh 3, and may flow axially along the inner wall of the smoke guide ring 1 towards the interior of the range hood. The oil-blocking flange 13 extends circumferentially along the smoke guide ring 1 and protrudes from its inner wall towards the center, forming an axial barrier against the oil flowing backward along the inner wall of the smoke guide ring 1, making it difficult for the oil to directly cross the rear end of the smoke guide ring 1 and enter the fan, volute, and other internal areas of the range hood. An inner oil drain hole 14 on the circumferential wall of the smoke guide ring 1 is located in the oil collection area corresponding to the oil-blocking flange 13. The oil blocked by the oil-blocking flange 13 can collect in this area and be discharged through the inner oil drain hole 14. In specific products, one or more internal oil drain holes 14 and external oil drain holes 16 can be provided, or they can be further connected to an oil tank, oil cup, or oil drain pipe. Thus, the oil baffle ring 15 is mainly used to prevent the oil generated by the front-end second separation net 4 from continuing to enter the area of ​​the first separation net 3, while the oil baffle flange 13 is mainly used to prevent the oil generated by the rear-end first separation net 3 and the oil residue on the inner wall of the smoke guide ring 1 from continuing to enter the range hood. The two form a continuous two-stage oil pollution isolation structure along the direction of oil smoke flow, which, together with the external oil drain hole 16 and the internal oil drain hole 14, forms an oil pollution treatment path of "front-stage separation - front-stage oil separation and discharge - rear-stage separation - rear-stage oil separation and discharge".

[0043] The smoke guide ring 1 is detachably equipped with a honeycomb filter 5 at its air inlet end. The honeycomb filter 5 covers the main air inlet area of ​​the smoke guide ring 1, and its surface forms multiple honeycomb-shaped flow units for the passage of oil fumes. The honeycomb filter 5 can initially intercept larger oil droplets, oil particles, or foreign objects before the oil fumes enter the high-speed rotating second separation net 4 and first separation net 3, and isolate the external area from the high-speed rotating separation nets, thus providing both primary filtration and safety protection. The outer periphery of the honeycomb filter 5 is connected to the air guide ring 6. The air guide ring 6 and the air inlet end of the smoke guide ring 1 are connected by a detachable structure, specifically using screw connections, snap-fit ​​connections, or other mechanical connection methods that allow for repeated disassembly and assembly. When a large amount of oil accumulates on the surface of the honeycomb filter 5, the air guide ring 6, together with the honeycomb filter 5, can be removed from the smoke guide ring 1 for cleaning or replacement, improving the convenience of use and maintenance.

[0044] Working principle: In use, this invention can be installed at the smoke inlet of a range hood, integrated stove, or other fume treatment equipment, placing the fume separator upstream of the exhaust fan and volute. When the range hood fan starts, a negative pressure is created in the fume duct, and the cooking fumes first enter the smoke guide ring 1 through the honeycomb filter 5. After the honeycomb filter 5 initially intercepts larger oil droplets and oil particles, the remaining fumes continue to move towards the dual-vortex mesh separation area. When the coaxial motor 2 is working, the second motor 22 drives the second separation mesh 4 located at the front end to rotate via the drive shaft 23, while the first motor 21 drives the first separation mesh 3 located at the rear to rotate in the opposite direction. When the fumes first pass through the second separation mesh 4, due to the high circumferential speed of the mesh strips of the second separation mesh 4, and the overall movement of the fumes along the axial direction of the smoke guide ring 1, a significant relative motion is formed between the mesh strips of the second separation mesh 4 and the oil droplets and oil mist. The high-speed mesh actively sweeps across the fume flow area, causing some oil droplets and oil mist to collide with the mesh and adhere to its surface. Small oil droplets further coalesce to form larger oil, which then moves radially outward under the centrifugal force generated by the rotation of the second separation mesh 4, and is eventually thrown onto the inner wall of the smoke guide ring 1, thus forming the dynamic collision capture, oil droplet coalescence and centrifugal oil throwing process in the front stage.

[0045] The fine oil mist that was not captured at the second separation net 4 continues to move with the airflow towards the first separation net 3. However, this remaining oil mist, after passing through the high-speed rotating second separation net 4, has its motion disturbed by the preceding rotating structure. In addition to directly colliding with the oil droplets, the rotating mesh of the second separation net 4 also exerts a circumferential effect on the surrounding airflow, causing the local airflow and the residual oil mist it carries to have a certain tangential motion tendency after passing through its mesh openings. If the subsequent separation net continues to rotate in the same direction as the second separation net 4, the direction of its mesh movement may partially coincide with the tangential motion tendency of the residual oil mist, thus limiting the degree of relative motion enhancement between the subsequent stage and the residual oil mist. In this invention, the first separating net 3 adopts a rotation direction opposite to that of the second separating net 4. When the remaining oil fumes that have been disturbed by the rotation of the second separating net 4 enter the area where the first separating net 3 is located, the net strips of the first separating net 3 sweep across the oil fume channel again in a direction different from the previous stage, thereby forming a second dynamic action on the residual oil fumes in the opposite direction. This is beneficial to increase the relative movement between the net strips of the first separating net 3 and the residual oil droplets and oil mist, and to increase the chance of the two movement trajectories intersecting.

[0046] In this process, the oil mist that originally failed to effectively intersect with the mesh strips at the second separation mesh 4 can now collide, adhere to, and coalesce with the high-speed mesh strips again, and then be thrown outwards under the centrifugal force generated by the first separation mesh 3. Therefore, the present invention does not form a simple repeated filtration produced by two separation meshes connected in series, but rather a continuous separation process of "front-stage dynamic collision and airflow disturbance - change in the motion state of remaining oil fumes - rear-stage reverse dynamic action". The two separation stages are related in terms of the motion state of the oil fumes, enabling the rear stage to form a re-capture effect in different directions on the remaining oil fumes that have been disturbed by the front stage, which helps to reduce the possibility of fine oil mist continuously passing through the two rotating separation meshes along an approximate trajectory.

[0047] In the aforementioned two-stage dynamic separation process, the oil contaminants captured by the two separation nets exit the main fume channel through the oil-blocking and draining structures corresponding to their respective separation areas. After the oil generated by the second separation net 4 is centrifugally thrown to the inner wall of the smoke guide ring 1, if it continues to move backward along the direction of fume flow, it will first be blocked by the oil-blocking ring 15 located between the second separation net 4 and the first separation net 3. The oil-blocking ring 15 extends from the inner circumference of the smoke guide ring 1 towards the center, forming an annular oil-blocking barrier on the inner wall of the smoke guide ring 1. This prevents the oil contaminants separated by the second separation net 4 from easily flowing axially along the inner wall of the smoke guide ring 1 into the working range of the first separation net 3. The blocked oil contaminants gather in the area in front of the oil-blocking ring 15 and are discharged through the external oil drain hole 16. This not only reduces the re-entry of the oil contaminants already separated in the previous stage into the subsequent airflow but also reduces the possibility of secondary contamination of the surface of the first separation net 3 by the oil from the previous stage, allowing the first separation net 3 to primarily perform subsequent dynamic separation of the remaining oil mist not separated in the previous stage.

[0048] After passing through the first separation net 3, the oil trapped by the first separation net 3 and the oil on the inner wall of the rear smoke guide ring 1 continue to be subjected to centrifugal force and wall surface collection. If this part of the oil continues to flow axially backward along the inner wall of the smoke guide ring 1, it may directly enter the fan, volute, and internal exhaust area of ​​the range hood. To address this, the present invention provides an oil-blocking flange 13 extending towards the center at the rear end of the smoke guide ring 1. The oil-blocking flange 13 blocks and isolates the oil located on the inner wall of the smoke guide ring 1 and moving axially towards the rear end, preventing this part of the oil from easily crossing the rear end of the smoke guide ring 1 into the range hood. Instead, it is confined to the oil collection area in front of the oil-blocking flange 13 and discharged through the internal oil drain hole 14. Thus, during the axial movement of the fumes from front to back, the oil-blocking ring 15 first forms a front-stage oil-blocking isolation between the second separation net 4 and the first separation net 3, and the oil-blocking flange 13 further forms a rear-stage oil-blocking isolation between the first separation net 3 and the interior of the range hood. The two oil separation structures work together with the external oil drain hole 16 and the internal oil drain hole 14 to ensure that the oil collected by the two separation nets is discharged to the outside of the smoke ring 1 in a timely manner according to their respective areas, instead of flowing backward step by step along the inner wall of the smoke ring 1.

[0049] Through the above structure, the present invention forms a complete oil fume treatment process matching the two-stage reverse dynamic oil fume separation. Firstly, the oil fume undergoes primary dynamic separation via the front-end second separation net 4. The oil generated by the second separation net 4 is isolated by the oil-blocking ring 15 and discharged through the external oil outlet 16. The remaining oil fume continues to undergo secondary dynamic separation via the rear-end first separation net 3, which rotates in the opposite direction. The oil generated by the first separation net 3 and the oil on the inner wall of the rear smoke guide ring 1 are then axially isolated by the oil-blocking flange 13 and discharged through the internal oil outlet 14. The airflow after the two-stage separation continues to enter the rear fan and volute. In other words, the oil-blocking ring 15 is not simply a reinforcing structure or a common oil-receiving flange, but rather, together with the second separation net 4 and the external oil outlet 16, constitutes the front-stage oil fume isolation and discharge unit. Similarly, the oil-blocking flange 13 is not simply a structural flange, but rather, together with the first separation net 3 and the internal oil outlet 14, forms the rear-stage oil fume isolation and discharge unit. Both work in conjunction with the coaxially rotating dual separation nets. This allows the oil fume airflow to be continuously transported backward along the axial direction, while the liquid oil separated from the oil fume is thrown out radially and blocked axially in their respective separation areas and discharged in a timely manner, thus achieving the separation of the airflow path and the oil flow path.

[0050] After undergoing the aforementioned two-stage reverse dynamic separation and two-stage oil contamination isolation treatment, the airflow continues to enter the rear fan, volute, and exhaust channel from the outlet of the smoke guide ring 1. Since a large amount of liquid oil droplets and oil mist have been continuously captured by the second separation net 4 and the first separation net 3 before entering the fan, and the separated oil contaminants are restricted to the corresponding area by the oil baffle ring 15 and the oil baffle flange 13 before being discharged outward through the external oil discharge hole 16 and the internal oil discharge hole 14, it can reduce the oil mist content entering the rear fan and reduce the direct flow of separated liquid oil contaminants into the range hood along the inner wall of the smoke guide ring 1, thereby reducing oil contamination on the fan impeller, volute, and exhaust channel. Meanwhile, the first motor 21 and the second motor 22 are arranged along the same axis of rotation. The second motor 22 transmits power to the second separation net 4 at the front end through the drive shaft 23 passing through the central area of ​​the first motor 21, so that the rotation outputs in two opposite directions are concentrated in the central area of ​​the smoke guide ring 1. There is no need to set two independent drive mechanisms on the radial periphery of the smoke guide ring 1. Therefore, it can not only meet the drive requirements of the two separation nets rotating independently in opposite directions, but also keep the entire oil fume separation device with a small radial dimension and good central symmetry, making it easy to manufacture as a whole module and install it at the smoke inlet of the existing range hood.

[0051] In practical use, the first separating mesh 3 and the second separating mesh 4 are not limited to fixed-speed operation. The coaxial motor 2 can control the speed of the first motor 21 and the second motor 22 separately according to different working levels of the range hood. For example, a lower speed is used when the amount of oil fume is small, and the speed of the two separating meshes is increased when there is a large amount of oil fume, such as stir-frying. The two separating meshes can be used in a constant-speed reverse rotation with basically the same absolute speed value, or in a differential-speed reverse rotation with different absolute speed values. By adjusting the speed of the first motor 21 and the second motor 22 respectively, the dynamic separation intensity of the front and rear stages can be adjusted according to different oil fume flow and concentration while keeping the two separating meshes rotating in opposite directions. The number of mesh strips, the shape of the mesh strips, the mesh spacing and the radial dimensions of the first separating mesh 3 and the second separating mesh 4 can also be designed according to the actual oil fume treatment capacity. The front and rear separating meshes can use the same structural parameters, or different structural parameters can be used for different working conditions such as higher oil fume concentration in the front stage and relatively smaller residual oil mist particle size in the rear stage.

[0052] Furthermore, this invention can be directly installed as part of the smoke intake system in newly manufactured range hoods, or a corresponding installation interface can be designed according to the size of the smoke inlet of different range hoods. The smoke guide ring 1, coaxial motor 2, first separation mesh 3, second separation mesh 4, honeycomb filter 5, and related oil and grease isolation and discharge structures are combined into a relatively independent pre-mounted oil fume separation module, which is then installed at the smoke inlet of an existing range hood. When using a modular installation method, the original range hood's fan is still mainly responsible for generating the negative pressure required to extract oil fumes. This invention, however, mainly undertakes the active separation and oil and grease blocking functions before the oil fumes enter the fan. It does not require significant modifications to the original fan and volute main structure, and can add a two-stage reverse rotation oil fume separation and graded oil and grease isolation and discharge function upstream, thereby reducing the oil and grease load inside the range hood and extending the equipment cleaning and maintenance cycle.

[0053] It should be noted that the above specific embodiments are merely preferred embodiments of the present invention. Any equivalent substitutions or adaptive changes made by those skilled in the art to the shape, size, quantity, specific connection form, or installation position of the components based on the above disclosure, without departing from the basic concept of the present invention, should fall within the protection scope of the present invention. The specific protection scope is defined by the claims.

Claims

1. A coaxial reverse-rotating double-swirl screen oil fume separator, comprising a smoke guide ring (1) and a coaxial motor (2) disposed at the center of the smoke guide ring (1), wherein the smoke guide ring (1) forms an oil fume channel for oil fumes to pass through, characterized in that: The coaxial motor (2) includes a first motor (21) and a second motor (22) arranged sequentially along the axial direction, and the rotation axes of the first motor (21) and the second motor (22) coincide. The rotor of the second motor (22) is connected to one end of the drive shaft (23), the drive shaft (23) passes through the first motor (21) along the rotation axis of the first motor (21), and the other end of the drive shaft (23) extends out of the first motor (21). The fume duct is provided with a first separation net (3) and a second separation net (4). The first separation net (3) and the second separation net (4) are arranged at intervals along the axial direction of the fume duct and are both arranged on the flow path of the fume. The first separating mesh (3) is connected to the rotor of the first motor (21), and the second separating mesh (4) is connected to the other end of the drive shaft (23); The first motor (21) and the second motor (22) have opposite output rotation directions to drive the first separating net (3) and the second separating net (4) to rotate in opposite directions around the rotation axis, respectively.

2. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 1, characterized in that: The smoke guide ring (1) is circular. A plurality of connecting ribs (11) extending toward its center are provided on one axial end of the smoke guide ring (1). The inner ends of the plurality of connecting ribs (11) are connected to the motor base (12) located at the center of the smoke guide ring (1). The coaxial motor (2) is mounted on the motor base (12).

3. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 2, characterized in that: The coaxial motor (2) has a sealing seat (25) on its outer cover. The sealing seat (25) is sealed to the motor base (12) and together they enclose a sealing cavity (26) for accommodating the coaxial motor (2).

4. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 1, characterized in that: The stators of the first motor (21) and the second motor (22) are both mounted on the motor frame (24), which is fixed relative to the smoke guide ring (1).

5. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 1, characterized in that: One axial end of the smoke guide ring (1) is provided with an oil-blocking flange (13) extending toward the center of the smoke guide ring (1).

6. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 5, characterized in that: An inner oil drain hole (14) is provided on the peripheral wall of the smoke guide ring (1), and the inner oil drain hole (14) is located on the radial outer side of the oil-blocking flange (13).

7. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 1, characterized in that: An oil baffle (15) is provided on the inner peripheral wall of the smoke guide ring (1) extending toward its center. The oil baffle (15) is located between the first separation net (3) and the second separation net (4) along the axial direction of the smoke guide ring (1).

8. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 7, characterized in that: An external oil drain hole (16) is provided on the peripheral wall of the smoke guide ring (1), and the external oil drain hole (16) is located on the radial outer side of the oil baffle ring (15).

9. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 1, characterized in that: The air inlet end of the smoke guide ring (1) is detachably fitted with a honeycomb filter (5).

10. The coaxial reverse-rotating double-swirl screen oil fume separator according to claim 9, characterized in that: The outer periphery of the honeycomb filter (5) is connected to the air guide ring (6), and the air guide ring (6) is detachably connected to the air inlet end of the smoke guide ring (1).

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