Smoke pipe backflow prevention device

Abstract

The utility model provides a kind of flue pipe backflow prevention device.The flue pipe backflow prevention device includes: pipe body, fairing and multiple blades;Fairing is located in pipe body;Multiple blades are arranged along the circumferential direction of fairing, and the two ends of each blade along the radial direction are fixed to the outside of fairing and the inner wall of pipe body respectively, and along the axial direction, each blade includes opposite head end and tail end, and each blade extends obliquely along the circumferential direction from head end to tail end;Air inlet is formed at the head end of multiple blades, and air outlet is formed at the tail end of multiple blades;The cross-sectional area of air inlet is greater than the cross-sectional area of air outlet.By setting the cross-sectional area of air inlet greater than the cross-sectional area of air outlet, the air pressure on the air inlet side is less than the air pressure on the air outlet side, preventing the airflow from flowing backward into the air outlet through the common flue connected to the air outlet.

Description

Technical Field

[0001] This utility model relates to a backflow prevention device for flue pipes. Background Technology

[0002] In existing flue pipes, insufficient pipe pressure usually occurs when the flue pipe is too long or the AC motor is not powerful enough. When the pipe is too long and the pressure is insufficient, the industry solution is to add an auxiliary exhaust fan to help the main fan exhaust smoke. When the insufficient pipe pressure is caused by the motor's insufficient performance, the only solution is to replace it with a DC motor to increase the pressure.

[0003] During peak cooking hours, excessive pressure in the public exhaust duct can cause backflow of cooking fumes if the static pressure provided by the user's range hood is insufficient, or if other users are using their range hoods while their own is not. In addition to increasing the static pressure when the range hood is running, the industry's solutions for backflow prevention include installing a check valve when the range hood is not running.

[0004] However, the above settings have the following problems:

[0005] 1. Adding an auxiliary exhaust fan can effectively increase the duct pressure, but the addition of a new fan brings the following disadvantages: 1) The control difficulty of the entire system increases because a new fan system is connected in series; 2) A new fan system includes a fan, motor, and controller, which will significantly increase the user's operating costs; 3) The auxiliary exhaust fan is usually installed between the public flue and the range hood, which is usually in the ceiling, thus increasing the maintenance costs for the business; 4) The series operation of the fans will increase aerodynamic noise.

[0006] 2. Replacing the motor with a DC motor can effectively improve the performance of the range hood. However, DC motors require a control system, which increases costs significantly more than AC motors. Furthermore, converting an AC motor to a DC motor can cause compatibility issues, as older models may not be compatible with newer models. Utility Model Content

[0007] The technical problem this invention aims to solve is how to prevent airflow from the public flue from entering the range hood in a user's home while effectively controlling costs, by providing a flue backflow prevention device.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] A backflow prevention device for flue pipes, characterized in that it comprises:

[0010] tube body;

[0011] A fairing, wherein the fairing is located within the tube body and the axial direction of the fairing is the same as the axial direction of the tube body;

[0012] Multiple blades are arranged at intervals along the circumference of the fairing. Each blade is fixed at both ends of the fairing radially to the outer side of the fairing and the inner wall of the tube, respectively. Each blade also includes a head end and a tail end along the axial direction of the fairing. Each blade extends obliquely along the circumference from the head end to the tail end.

[0013] An air inlet is formed between the outer side of the fairing and the inner wall of the tube at the leading end of the plurality of blades, and an air outlet is formed between the outer side of the fairing and the inner wall of the tube at the trailing end of the plurality of blades.

[0014] The cross-sectional area of ​​the air inlet is larger than the cross-sectional area of ​​the air outlet.

[0015] In this technical solution, by setting the cross-sectional area of ​​the air inlet to be larger than that of the air outlet, when the airflow passes through the blades from the air inlet, the flow resistance between adjacent blades increases due to the smaller air outlet. This results in the air pressure on the air inlet side being lower than that on the air outlet side, preventing airflow from flowing back into the air outlet through the common flue connected to it. Furthermore, because the flue anti-backflow device has a simple mechanical structure, manufacturing costs can be effectively controlled, and it has an excellent service life. Additionally, by setting the blades to extend obliquely circumferentially from the first to the last end, noise generated by the airflow can be reduced.

[0016] Preferably, the direction from the air inlet to the air outlet is the flow direction;

[0017] Along the flow direction, the fairing includes a head section, a middle section, and a tail section connected in sequence, with the middle section located between the head end and the tail end of the blade.

[0018] Preferably, the outer diameter of the head gradually increases from away from the middle to near the middle; the outer diameter of the tail gradually decreases from near the middle to away from the middle.

[0019] In this technical solution, by setting the outer diameter of the head to gradually increase from the direction away from the center to the direction closer to the center, the cross-sectional size of the air inlet can be adjusted, and the airflow can be effectively guided. By setting the outer diameter of the tail to gradually decrease from the direction closer to the center to the direction away from the center, the cross-sectional size of the air outlet can be adjusted, and the airflow can be effectively guided.

[0020] Preferably, the backflow prevention device for the flue also includes a reverse airflow buffer assembly, which is used to buffer the reverse airflow generated at the tail of the fairing.

[0021] In this technical solution, by setting a reverse airflow buffer component, the reverse airflow generated at the tail of the fairing can be buffered, thus ensuring airflow stability.

[0022] Preferably, the reverse airflow buffer assembly includes a plurality of guide vanes, which are arranged at circumferential intervals along the fairing. One end of each guide vane is fixed to the outside of the fairing, and the other end extends radially away from the fairing.

[0023] The multiple guide vanes each have a first end and a second end along the axial direction of the fairing, with the second end being closer to the tail end than the first end. Each blade extends obliquely along the circumferential direction from the first end to the second end, and the tilting direction of the guide vane is the same as the tilting direction of the blade.

[0024] In this technical solution, by setting guide vanes, the reverse airflow generated at the tail of the fairing can be buffered, thus ensuring airflow stability. Furthermore, by setting guide vanes to extend obliquely in the circumferential direction from the first end to the second end, and the tilting direction of the guide vanes is the same as the tilting direction of the blades, the noise generated by the airflow can be further reduced.

[0025] Preferably, the radial projection of the first end of the guide vane does not coincide with the radial projection of the blade, and the radial projection of the second end of the guide vane is located within the radial projection of the tail portion of the fairing; and / or,

[0026] A flow channel connecting the air inlet and the air outlet is formed between two adjacent blades, and the end of the guide vane away from the shroud along the radial direction does not exceed the center position of the corresponding flow channel along the radial direction; and / or,

[0027] The number of blades is n, and the number of guide vanes is m, where n and m are integers, where 6 ≤ n ≤ 15; when n is even, 3 ≤ m ≤ n * 1 / 2; when n is odd, 3 ≤ m ≤ (n + 1) * 1 / 2; and / or,

[0028] The tilt angle of the guide vane is equal to the tilt angle of the blade; and / or,

[0029] The size of the guide vane gradually decreases from the first end to the second end.

[0030] In this technical solution, the flow stabilization effect of the guide vane is further improved by the specific structural design of the guide vane described above.

[0031] Preferably, the reverse airflow buffer assembly further includes a buffer section, which is the end face of the tail portion away from the middle portion, and is recessed into the tail portion in a direction opposite to the flow direction.

[0032] In this technical solution, by setting up a buffer section, the reverse airflow generated at the tail of the fairing can be buffered, thus ensuring airflow stability.

[0033] Preferably, the surface of the buffer portion is provided with a plurality of spaced protrusions, and the plurality of protrusions extend in the same direction, and a guide groove is formed between two adjacent protrusions.

[0034] In this technical solution, by setting convex strips and the guide grooves formed between two adjacent convex strips, the reverse airflow generated at the tail of the fairing can be better buffered and stabilized, and the instantaneous pressure of the reverse airflow can be effectively prevented.

[0035] Preferably, the convex strip has an irregular arc-shaped structure.

[0036] In this technical solution, by setting the convex strip to an irregular arc-shaped structure, the resistance to airflow can be increased, thereby playing a better role in buffering airflow.

[0037] Preferably, the pipe body is provided with a first flow guide near the air inlet, the first flow guide being used to guide the airflow near the inner wall of the pipe body to the air inlet; and / or,

[0038] The pipe body is provided with a second flow guide near the air outlet, and the second flow guide is used to guide the airflow flowing out of the air outlet radially outward.

[0039] The positive and progressive effects of this utility model are as follows:

[0040] This invention, by setting the cross-sectional area of ​​the air inlet to be larger than that of the air outlet, ensures that when airflow passes through the blades from the air inlet, the flow resistance between adjacent blades increases due to the smaller air outlet. This results in the air pressure on the air inlet side being lower than that on the air outlet side, preventing airflow from flowing back into the air outlet through the common flue connected to it. Furthermore, because the flue anti-backflow device has a simple mechanical structure, manufacturing costs can be effectively controlled, and it has an excellent service life. Additionally, by setting the blades to extend obliquely circumferentially from the first to the last end, it can reduce the noise generated by the airflow. Attached Figure Description

[0041] Figure 1 This is a three-dimensional structural diagram of a flue anti-backflow device according to a preferred embodiment of the present invention.

[0042] Figure 2 This is a cross-sectional structural schematic diagram of a preferred embodiment of the flue anti-backflow device of the present utility model.

[0043] Figure 3This is a partial three-dimensional structural schematic diagram (I) of a preferred embodiment of the flue anti-backflow device of the present utility model.

[0044] Figure 4 This is a partial three-dimensional structural schematic diagram (II) of the flue anti-backflow device according to a preferred embodiment of the present invention.

[0045] Figure 5 This is a partial front view structural schematic diagram of a flue anti-backflow device according to a preferred embodiment of the present invention.

[0046] Figure 6 This is a partial left-side view of the flue anti-backflow device according to a preferred embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures

[0048] Backflow prevention device 1

[0049] Tube body 10

[0050] Fairing 20

[0051] First 21

[0052] Central 22

[0053] Tail 23

[0054] 30 leaves

[0055] Head 31

[0056] Tail end 32

[0057] Air inlet 40

[0058] 50 air outlet

[0059] Reverse airflow buffer assembly 60

[0060] Guide vane 61

[0061] First end 611

[0062] Second end 612

[0063] Buffer section 62

[0064] Raised strip 63

[0065] 64 guide channel

[0066] Flow channel 80

[0067] Axial P of the fairing

[0068] Axial Q of the tube body

[0069] Radial R of the fairing

[0070] Section S1 of the air inlet

[0071] The cross-section S2 of the air outlet

[0072] Flow direction F Detailed Implementation

[0073] The embodiments of this utility model are described in detail below. Examples of the 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 intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the protection scope of this utility model.

[0074] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and 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, and therefore should not be construed as a limitation of this utility model.

[0075] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0076] like Figures 1 to 6 As shown, this embodiment provides a backflow prevention device 1 for a flue. The backflow prevention device 1 includes: a pipe body 10, a shroud 20, and multiple blades 30.

[0077] The fairing 20 is located in the tube body 10, and the axial direction P of the fairing 20 is in the same direction as the axial direction Q of the tube body 10.

[0078] Multiple blades 30 are arranged at intervals along the circumference of the fairing 20. Each blade 30 is fixed at both ends along the radial R of the fairing 20 to the outer side of the fairing 20 and the inner wall of the tube 10, respectively. Each blade 30 includes a head end 31 and a tail end 32 along the axial P of the fairing 20. Each blade 30 extends obliquely along the circumference from the head end 31 to the tail end 32.

[0079] An air inlet 40 is formed between the outer side of the fairing 20 and the inner wall of the tube body 10 at the leading end 31 of the multiple blades 30, and an air outlet 50 is formed between the outer side of the fairing 20 and the inner wall of the tube body 10 at the trailing end 32 of the multiple blades 30.

[0080] Among them, the cross-sectional area of ​​the air inlet 40 is larger than that of the air outlet 50.

[0081] In this way, by setting the cross-sectional area of ​​the air inlet 40 to be larger than that of the air outlet 50, when the airflow passes through the blades 30 from the air inlet 40, the resistance of the flow channel 80 formed between two adjacent blades 30 increases due to the smaller size of the air outlet 50. This results in the air pressure on the air inlet 40 side being lower than that on the air outlet 50 side, thus preventing the airflow from flowing back into the air outlet 50 through the common flue connected to it. Moreover, since the structure of the flue anti-backflow device 1 is a simple mechanical structure, manufacturing costs can be effectively controlled, and it has an excellent service life. Furthermore, by setting the blades 30 to extend obliquely in the circumferential direction from the first end 31 to the last end 32, the noise generated by the airflow can be reduced. It should be noted that the cross-sectional area of ​​the air inlet 40 is the area of ​​the air inlet cross-section S1; the cross-sectional area of ​​the air outlet 50 is the area of ​​the air outlet cross-section S2.

[0082] In this embodiment, the direction from the air inlet 40 to the air outlet 50 is the flow direction F. Along the flow direction F, the fairing 20 includes a head portion 21, a middle portion 22 and a tail portion 23 connected in sequence, with the middle portion 22 located between the head end 31 and the tail end 32 of the blade 30.

[0083] Preferably, the outer diameter of the head portion 21 gradually increases from the direction away from the middle portion 22 to the direction closer to the middle portion 22, so as to adjust the cross-sectional size of the air inlet 40 and effectively guide the airflow.

[0084] The outer diameter of the tail section 23 gradually decreases from near the middle section 22 to far away from the middle section 22, so as to adjust the cross-sectional size of the air outlet 50 and effectively guide the airflow.

[0085] Preferably, the flue anti-backflow device 1 further includes a reverse airflow buffer assembly 60, which is used to buffer the reverse airflow generated at the tail 23 of the shroud 20. In this way, by providing the reverse airflow buffer assembly 60, the reverse airflow generated at the tail 23 of the shroud 20 can be buffered, ensuring airflow stability.

[0086] Specifically, the reverse airflow buffer assembly 60 includes multiple guide vanes 61, which are arranged at intervals along the circumference of the fairing 20. One end of each guide vane 61 is fixed to the outside of the fairing 20, and the other end extends radially away from the fairing 20 along the radial direction R. Each guide vane 61 includes a first end 611 and a second end 612 along the axial direction P of the fairing 20. The second end 612 is closer to the tail 23 than the first end 611. Each blade 30 extends obliquely circumferentially from the first end 611 to the second end 612, and the tilting direction of the guide vane 61 is the same as the tilting direction of the blade 30. In this way, by setting the guide vanes 61, the reverse airflow generated at the tail 23 of the fairing 20 can be buffered, ensuring airflow stability. Furthermore, by setting the guide vanes 61 to extend obliquely circumferentially from the first end 611 to the second end 612, and the tilting direction of the guide vanes 61 is the same as the tilting direction of the blade 30, the noise generated by the airflow can be further reduced.

[0087] Preferably, the projection of the first end 611 of the guide vane 61 along the radial direction R does not coincide with the projection of the blade 30 along the radial direction R, and the projection of the second end 612 of the guide vane 61 along the radial direction R is located within the projection of the tail 23 of the fairing 20 along the radial direction R, so as to further improve the flow stabilization effect of the guide vane 61.

[0088] A flow channel 80 is formed between two adjacent blades 30, connecting the air inlet 40 and the air outlet 50. The end of the guide vane 61 that is far away from the shroud 20 along the radial direction R does not exceed the center position of the corresponding flow channel 80 along the radial direction R, so as to further improve the flow stabilization effect of the guide vane 61.

[0089] The number of blades 30 is n, and the number of guide vanes 61 is m, where n and m are integers, and 6 ≤ n ≤ 15. When n is even, 3 ≤ m ≤ n * 1 / 2; when n is odd, 3 ≤ m ≤ (n + 1) * 1 / 2. Due to the lack of moving blades and the limited space in the tube body 10, the number of blades should not exceed 15. Simultaneously, to reduce airflow noise, the number of blades should not be less than 6. The number of guide vanes 61 corresponds to the number of blades 30 to improve flow stabilization.

[0090] The tilt angle of guide vane 61 is equal to the tilt angle of blade 30, so as to further improve the flow stabilization effect of guide vane 61.

[0091] The size of the guide vane 61 gradually decreases from the first end 611 to the second end 612 in order to further improve the flow stabilization effect of the guide vane 61.

[0092] The guide vane 61 is triangular in shape, but is not limited to this. The shape of the guide vane 61 can be changed to other shapes, such as circular, elliptical or other irregular fan blades.

[0093] Furthermore, the reverse airflow buffer assembly 60 also includes a buffer section 62, which is the end face of the tail 23 away from the middle section 22, and is recessed into the tail 23 in the direction opposite to the flow direction F. In this way, by providing the buffer section 62, the reverse airflow generated at the tail 23 of the fairing 20 can be buffered, thus ensuring airflow stability.

[0094] It should be noted that in other embodiments, only the buffer section 62 or only the guide vane 61 may be provided.

[0095] The cross-section of the buffer part 62 is a concave cone shape, and the angle α formed at the apex of the cone is greater than or equal to 135 degrees and less than 180 degrees.

[0096] In this embodiment, the surface of the buffer section 62 is provided with a plurality of spaced protrusions 63, and the plurality of protrusions 63 extend in the same direction. A guide groove 64 is formed between two adjacent protrusions 63. In this way, by providing the protrusions 63 and the guide groove 64 formed between two adjacent protrusions 63, the reverse airflow generated at the tail 23 of the fairing 20 can be better buffered and stabilized, and the instantaneous pressure of the reverse airflow can be effectively prevented.

[0097] Furthermore, the convex strip 63 has an irregular arc-shaped structure to increase resistance to airflow, thereby providing a better buffering effect on airflow.

[0098] The height of the protrusion 63 is 4mm-8mm, that is, the depth of the guide groove 64 formed between two adjacent protrusions 63 is 4mm-8mm.

[0099] The width of the guide groove 64 is 6mm-15mm, that is, the distance between two adjacent protrusions 63 is 6mm-15mm. By setting the range of the width of the guide groove 64, on the one hand, it avoids the width being too small, thus avoiding excessive resistance to airflow; on the other hand, it avoids the width being too large, thus failing to play a good role in buffering and stabilizing.

[0100] The pipe body 10 is provided with a first guide section 11 near the air inlet 40. The first guide section 11 is used to guide the airflow near the inner wall of the pipe body 10 to the air inlet 40.

[0101] The pipe body 10 is provided with a second flow guide 12 near the air outlet 50. The second flow guide 12 is used to guide the airflow flowing out of the air outlet 50 radially R outward.

[0102] In this embodiment, by setting the cross-sectional area of ​​the air inlet 40 to be larger than that of the air outlet 50, when the airflow passes through the blades 30 from the air inlet 40, the resistance of the flow channel 80 formed between two adjacent blades 30 increases due to the smaller size of the air outlet 50. This results in the air pressure on the air inlet 40 side being lower than that on the air outlet 50 side, thus preventing the airflow from flowing back into the air outlet 50 through the common flue connected to it. Moreover, since the structure of the flue anti-backflow device 1 is a simple mechanical structure, manufacturing costs can be effectively controlled, and it has an excellent service life. Furthermore, by setting the blades 30 to extend obliquely in the circumferential direction from the first end 31 to the last end 32, the noise generated by the airflow can be reduced.

[0103] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A backflow prevention device for flue pipes, characterized in that, It includes: tube body; A fairing, wherein the fairing is located within the tube body and the axial direction of the fairing is the same as the axial direction of the tube body; Multiple blades are arranged at intervals along the circumference of the fairing. Each blade is fixed at both ends of the fairing radially to the outer side of the fairing and the inner wall of the tube, respectively. Each blade also includes a head end and a tail end along the axial direction of the fairing. Each blade extends obliquely along the circumference from the head end to the tail end. An air inlet is formed between the outer side of the fairing and the inner wall of the tube at the leading end of the plurality of blades, and an air outlet is formed between the outer side of the fairing and the inner wall of the tube at the trailing end of the plurality of blades. The cross-sectional area of ​​the air inlet is larger than the cross-sectional area of ​​the air outlet.

2. The backflow prevention device for flue pipes as described in claim 1, characterized in that, The direction from the air inlet to the air outlet is the flow direction; Along the flow direction, the fairing includes a head section, a middle section, and a tail section connected in sequence, with the middle section located between the head end and the tail end of the blade.

3. The backflow prevention device for flue pipes as described in claim 2, characterized in that, The outer diameter of the head gradually increases from away from the middle to near the middle; the outer diameter of the tail gradually decreases from near the middle to away from the middle.

4. The backflow prevention device for flue pipes as described in claim 2, characterized in that, The backflow prevention device for the flue also includes a reverse airflow buffer assembly, which is used to buffer the reverse airflow generated at the tail of the fairing.

5. The backflow prevention device for flue pipes as described in claim 4, characterized in that, The reverse airflow buffer assembly includes multiple guide vanes, which are arranged at circumferential intervals along the fairing. One end of each guide vane is fixed to the outside of the fairing, and the other end extends radially away from the fairing. The multiple guide vanes each have a first end and a second end along the axial direction of the fairing, with the second end being closer to the tail end than the first end. Each blade extends obliquely along the circumferential direction from the first end to the second end, and the tilting direction of the guide vane is the same as the tilting direction of the blade.

6. The backflow prevention device for flue pipes as described in claim 5, characterized in that, The radial projection of the first end of the guide vane does not coincide with the radial projection of the blade; the radial projection of the second end of the guide vane is located within the radial projection of the tail portion of the fairing; and / or, A flow channel connecting the air inlet and the air outlet is formed between two adjacent blades, and the end of the guide vane away from the shroud along the radial direction does not exceed the center position of the corresponding flow channel along the radial direction; and / or, The number of blades is n, and the number of guide vanes is m, where n and m are integers, where 6 ≤ n ≤ 15; when n is even, 3 ≤ m ≤ n * 1 / 2; when n is odd, 3 ≤ m ≤ (n + 1) * 1 / 2; and / or, The tilt angle of the guide vane is equal to the tilt angle of the blade; and / or, The size of the guide vane gradually decreases from the first end to the second end.

7. The backflow prevention device for flue pipes as described in claim 4, characterized in that, The reverse airflow buffer assembly further includes a buffer section, which is the end face of the tail portion away from the middle portion, and is recessed into the tail portion in a direction opposite to the flow direction.

8. The backflow prevention device for flue pipes as described in claim 7, characterized in that, The surface of the buffer section is provided with a plurality of spaced protrusions, and the plurality of protrusions extend in the same direction, and a guide groove is formed between two adjacent protrusions.

9. The backflow prevention device for flue pipes as described in claim 8, characterized in that, The protrusion has an irregular arc-shaped structure.

10. The backflow prevention device for flue pipes as described in any one of claims 1-9, characterized in that, The pipe body is provided with a first flow guide near the air inlet, the first flow guide being used to guide the airflow near the inner wall of the pipe body to the air inlet; and / or, The pipe body is provided with a second flow guide near the air outlet, and the second flow guide is used to guide the airflow flowing out of the air outlet radially outward.

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