A centrifugal fan and a range hood using the same

Abstract

The application discloses a centrifugal fan and a range hood using the same. The centrifugal fan comprises a volute, which comprises an air inlet, an air inlet ring arranged at the air inlet, and a mesh cover installed to the air inlet ring and covering the radial inner side of the air inlet ring. The air inlet ring comprises a first mounting part, and the mesh cover comprises a second mounting part slidably mounted into the first mounting part along the axial direction of the centrifugal fan. The centrifugal fan further comprises a sealing strip arranged between the air inlet ring and the mesh cover. Compared with the prior art, the centrifugal fan has the advantages that the mesh cover and the air inlet ring are slidably disassembled, the operation is very convenient, and the air leakage path formed by the cooperation gap between the mesh cover and the air inlet ring is blocked by the sealing strip without affecting the sliding of the mesh cover, so that normal air intake is ensured.

Description

Technical Field

[0001] This invention relates to power devices, particularly a centrifugal fan, and a range hood using the centrifugal fan. Background Technology

[0002] As a kitchen appliance, the main function of a range hood is to extract and exhaust cooking fumes, reducing the harm to the operator caused by the fumes. The core power source of a range hood is a multi-blade centrifugal fan. Its components generally consist of an air inlet ring, a multi-blade centrifugal impeller, a motor, a volute, and an exhaust hood. Driven by the motor, the impeller rotates at high speed, and the cooking fumes pass through the air inlet ring, impeller, and volute in sequence before being discharged through the exhaust hood. To reduce excessive adhesion of cooking fumes to the impeller and for safety (to prevent accidental injury from hand contact), a filter screen is usually laminated onto the air inlet ring to achieve the above purpose and also to reduce noise.

[0003] For example, a range hood disclosed in Chinese utility model patent application number 202223355334.X includes an air inlet ring, which includes a radial guide portion and an axial guide portion extending axially from the inner axis of the radial guide portion. An oil mesh assembly is provided on the inner side of the air inlet ring. The oil mesh assembly includes an arched first oil mesh and a second oil mesh disposed at the edge of the first oil mesh. In the flow path of the oil fumes, the second oil mesh is located downstream of the first oil mesh. Because the assembly and processing with the air inlet ring need to be considered, the oil mesh assembly is pressed into the same size structure as the axial guide portion and then welded together.

[0004] The oil filter assembly in the aforementioned patent is welded together with the air inlet ring and cannot be disassembled separately. It needs to be cleaned together with the air inlet ring during cleaning, and there are likely to be blind spots for cleaning at the connection between the oil filter assembly and the air inlet ring. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a centrifugal fan that is quick to install and remove the screen cover and has high reliability, in order to address the shortcomings of the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a range hood that uses the above-mentioned centrifugal fan.

[0007] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a centrifugal fan, comprising:

[0008] The volute, which includes the air inlet;

[0009] An air inlet ring is installed at the air inlet; and

[0010] A mesh cover, which is installed on the inner side of the inner circumference of the air inlet ring and covers the radial inner side of the air inlet ring; characterized in that:

[0011] The air inlet ring includes a first mounting part, and the mesh cover includes a second mounting part that is slidably installed into the first mounting part along the axial direction of the centrifugal fan;

[0012] The centrifugal fan also includes a sealing strip disposed between the air inlet ring and the mesh cover.

[0013] The mesh cover and air inlet ring can be easily slidably installed and removed, and the sealing strip can block the airflow leakage path formed by the gap between the mesh cover and the air inlet ring without affecting the sliding of the mesh cover, thus ensuring normal air intake.

[0014] Furthermore, to facilitate the formation of the first mounting portion and the sliding entry of the second mounting portion into the first mounting portion, the air inlet ring includes a mounting portion installed on the outer periphery of the air inlet and located on the outer side of the volute, and a guide portion extending from the inner periphery of the mounting portion toward the impeller inside the volute. The first mounting portion is formed at the end of the guide portion located inside the volute, and the side of the first mounting portion facing the inside of the volute is open. A notch is formed on the guide portion, and the first mounting portion communicates with the inner periphery of the guide portion through the notch.

[0015] Furthermore, to facilitate the formation of the second mounting portion, the mesh cover includes a mesh cover body and a frame formed on the outer periphery of the mesh cover body, and the second mounting portion is formed on the frame.

[0016] Furthermore, to ensure airtightness at all points, the sealing strip includes a first sealing part, a second sealing part, and a third sealing part. The first sealing part is engaged with the end of the guide part located inside the volute, thereby partially pressing it between the guide part and the frame of the mesh cover. The second sealing part is pressed between the first mounting part and the second mounting part. The third sealing part is connected between the first sealing part and the adjacent second sealing part. The third sealing part is closely attached to the notch of the air inlet ring at an adjacent position in the circumferential direction.

[0017] Furthermore, to facilitate quick assembly and disassembly of the mesh cover while reducing the impact of oil contamination, the first and second mounting parts are magnetically attached.

[0018] Furthermore, to prevent the mesh cover from detaching from the air inlet ring, a locking mechanism is movably provided on the first mounting part, and a bayonet is provided on the second mounting part, with the locking mechanism maintaining a tendency to be engaged in the bayonet.

[0019] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a range hood, characterized in that: it uses a centrifugal fan as described above.

[0020] Furthermore, to ensure good sealing performance, the sealing strip is a rubber strip, and the compressive strain of the sealing strip... satisfy:

[0021] in, The elastic modulus of the sealing strip. The pressure coefficient of the airflow passing through the centrifugal fan. Where is the air density, Q is the nominal maximum airflow of the range hood, and S is the flow area at the mesh cover. : is the maximum thrust that feels comfortable when operating the mesh cover with one hand, L is the total effective contact length of the sealing strip, and w is the average contact width between the sealing strip and the mesh cover.

[0022] Furthermore, to avoid excessive sliding resistance affecting the assembly and disassembly experience, the original thickness of the sealing strip must satisfy h:

[0023]

[0024] in, K represents the combined tolerance zone width of the air inlet ring and the sealing strip, where K is the safety factor of the sealing strip. for The maximum value, for The minimum value.

[0025] Furthermore, the air inlet of the volute faces the wall where the range hood is installed. Even with limited visual and operational space, the mesh cover can still be easily installed and removed by sliding it.

[0026] Compared with the prior art, the advantages of the present invention are: the mesh cover and the air inlet ring can be slidably disassembled and assembled, making the operation very convenient; and the sealing strip can block the airflow leakage path formed by the fit gap between the mesh cover and the air inlet ring without affecting the sliding of the mesh cover, thus ensuring normal air intake; and the sealing strip with a reasonable structure can block the airflow leakage path without affecting the sliding. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a centrifugal fan according to an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional view of a centrifugal fan according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the mesh cover installation structure of the centrifugal fan according to an embodiment of the present invention (viewed from the inside of the centrifugal fan outwards);

[0030] Figure 4 for Figure 3 A magnified view of part I (locked state);

[0031] Figure 5This is a partial schematic diagram of the unlocked state of the mesh cover installation structure of the centrifugal fan according to an embodiment of the present invention (and...). Figure 4 (Same perspective and scope);

[0032] Figure 6 This is an exploded view of the mesh cover installation structure of a centrifugal fan according to an embodiment of the present invention;

[0033] Figure 7 for Figure 6 A magnified schematic diagram of part II;

[0034] Figure 8 for Figure 6 A diagram illustrating further decomposition;

[0035] Figure 9 for Figure 8 A magnified schematic diagram of part III;

[0036] Figure 10 This is a schematic diagram of the sealing strip of the mesh cover mounting structure of the centrifugal fan according to an embodiment of the present invention;

[0037] Figure 11 for Figure 10 A magnified schematic diagram of part IV. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0040] See Figure 1 and Figure 2A centrifugal fan is disclosed, preferably used in range hoods, but also applicable to other situations requiring such a power device. When used in a range hood, this centrifugal fan can be controlled via a voice module. A controller, a voice receiving module, and a voice parsing module can be installed in the range hood. The voice receiving module receives user commands, and the voice parsing module parses these commands. Based on the parsed commands, the controller controls the fan to perform corresponding operations, thereby achieving intelligent control of the range hood and improving the user experience.

[0041] The centrifugal fan includes a volute 1, an impeller 2 disposed within the volute 1, and a motor 3 for driving the impeller 2 to rotate. An air inlet 11 is formed on the volute 1, and an air inlet ring 4 (i.e., air inlet ring 4) is disposed at the air inlet 11. The air inlet ring 4 guides airflow from outside the centrifugal fan into the centrifugal fan. The air inlet ring 4 includes a mounting portion 41 installed on the outer periphery of the volute 1, located on the outer side of the air inlet 11, and a guide portion 42 extending from the inner periphery of the mounting portion 41 towards the impeller 2 within the volute 1. The mounting portion 41 is annular, and the cross-section of the guide portion 42 may be arc-shaped, bulging outwards from the volute 1, or at least the portion located within the volute 1 may extend axially, where "axial" refers to the centrifugal fan's axis X ( ). Figure 2 (As shown in the image) the direction of extension; the term "axial" in the following text has the same meaning.

[0042] The centrifugal fan also includes a mesh cover 5, which is installed on the air inlet ring 4 and covers the radial inner side of the air inlet ring 4, thereby covering the air inlet 11 of the volute 1 together with the air inlet ring 4. This allows the centrifugal fan to meet safety requirements and further reduce the entry of oil fume particles into the centrifugal fan. In addition, it can also rectify the airflow and reduce the noise of the whole machine.

[0043] See Figures 3-11 The mesh cover 5 includes a mesh cover body 51 and a frame 52 formed on the outer periphery of the mesh cover body 51. The mesh cover body 51 is generally spherical and protrudes outward from the volute 1. Preferably, for better filtration, rectification and noise reduction effects, the mesh cover body 51 can be a honeycomb mesh cover. The frame 52 is used for installation with the air inlet ring 4, and the frame 52 is located radially inside the guide portion 42 of the air inlet ring 4.

[0044] The air inlet ring 4 is located inside the volute 1 and near the end of the impeller 2, i.e., the end of the guide section 42, and forms a first mounting portion 43. This first mounting portion 43 can be a hollow shape protruding outward from the guide section 42, thus forming a structure similar to a guide groove. The side of the first mounting portion 43 facing the impeller 2 is open. The guide section 42 forms a notch 421 at a position corresponding to the first mounting portion 43, so that the space between the first mounting portion 43 and the inner circumference of the guide section 42 is connected. The first mounting portion 43 is magnetic, such as being made of a permanent magnet (e.g., neodymium iron boron). The first mounting portion 43 has a certain axial depth. In this embodiment, the cross-section of the first mounting portion 43 is approximately triangular, and the vertex of the triangle is away from the guide section 42. Here, "cross-section" refers to a plane perpendicular to the axis X. Optionally, the cross-sectional shape of the first mounting portion 43 can also be selected as needed, such as rectangular, circular, etc. At least two first mounting portions 43 can be arranged at circumferential intervals along the air inlet ring 4.

[0045] A second mounting portion 53 is provided on the frame 52, which may be a hollow shape protruding outward from the frame 52. The number of second mounting portions 53 is the same as that of the first mounting portions 43, and the positions of the second mounting portions 53 correspond to those of the first mounting portions 43. The cross-sectional shape of the second mounting portion 53 is adapted to the first mounting portion 43, but the size of the second mounting portion 53 is smaller than that of the first mounting portion 43, so that it can be inserted into the first mounting portion 43 from the open side. The second mounting portion 53 may be equipped with a magnetic sheet that can be magnetically attracted to the first mounting portion 43, or it may be made of a magnetic material itself. The material of the magnetic sheet or the magnetic material of the second mounting portion 53 may be selected, such as low carbon steel. The materials of the mesh body 51 and the frame 52 of the mesh cover 5 need to be non-magnetically attracted to avoid malfunction of the pre-positioning function of the first mounting portion 43 and the second mounting portion 53.

[0046] The first mounting portion 43 is provided with a locking mechanism 6, which is movably connected to the first mounting portion 43. In this embodiment, it is a rotatable connection, allowing the locking mechanism 6 to rotate to the side of the first mounting portion 43 facing the impeller 2. The second mounting portion 53 is provided with a bayonet 531, which, in this embodiment, is formed on one side of a triangle. The locking mechanism 6 can be inserted into and held within the bayonet 531, or it can be disengaged from the bayonet 531 by external force (such as flicking with a finger) and rotated out of the sliding path of the second mounting portion 53. This structure, which keeps the locking mechanism 6 moving in one direction, such as by using an elastic element to apply tension or thrust, is a common structure in the art and will not be described in detail here.

[0047] During installation, the mesh cover 5 is brought close to the air inlet ring 4 from inside the volute 1 (at this time, the impeller 2 and motor 3 have not yet been installed). At this time, the protrusion of the mesh cover 5 faces outward from the air inlet 11. When the mesh cover 5 and the air inlet ring 4 are close to each other, the magnetic attraction will attract the mesh cover 5 to the approximately correct position, that is, the positions of the first mounting part 43 and the second mounting part 53 correspond, realizing the pre-positioning. Then, the locking mechanism 6 is opened, and the mesh cover 5 is slid outward from the volute 1 along the axial direction. During this process, the locking mechanism 6 is always in the state of being pushed open by the mesh cover 5 until the second mounting part 53 slides into place. Under the action of elastic restoring force, the locking mechanism 6 automatically rotates and locks into the slot 531, thus positioning and installing the mesh cover 5 as a whole.

[0048] When it is necessary to remove the mesh cover 5, first move the locking mechanism 6, and then slide the mesh cover 5 in the opposite direction.

[0049] This composite quick-release installation structure utilizes magnetic attraction to achieve initial adsorption and alignment of the mesh cover, followed by a simple linear sliding motion using the mechanical slide rail (guide groove inside the first mounting part 43) to complete the final locking. Installation can be completed with just "one-click and one-slide," making the operation quick and easy. The magnetic attraction is unaffected by oil stains, ensuring high reliability. The locking mechanism 6 provides good holding force and excellent vibration resistance. The first mounting part 43 ensures the accuracy and repeatability of the installation. Only the locking mechanism 6 needs to be moved, eliminating the need for external tools.

[0050] In addition, the above installation structure is particularly suitable for situations where the air inlet 11 faces the side of the wall where the range hood is installed and the installation environment is small. Since the locking mechanism 6 is located on the side facing the user, it can be operated very conveniently.

[0051] As mentioned above, since the mesh cover 5 and the inlet ring 4 need to slide relative to each other, a clearance must exist between them. This clearance can become a path for airflow leakage, especially in the negative pressure area at the inlet of the inlet ring 4. Leaking airflow will disrupt the main airflow field, potentially generating additional vortex noise and reducing the effective airflow of the fan.

[0052] Therefore, in this invention, the centrifugal fan also includes a sealing strip 7, which is disposed between the air inlet ring 4 and the mesh cover 5 to block the airflow leakage path without affecting sliding. The sealing strip 7 may be made of rubber.

[0053] The sealing strip 7 is a closed ring, comprising a first sealing portion 71 and a second sealing portion 72. The first sealing portion 71 is arc-shaped, and the second sealing portion 72 is located at the end of the first sealing portion 71, for clamping between the first mounting portion 43 and the second mounting portion 53 in the installed state. Therefore, the shape, number, and position of the second sealing portions 72 are adapted to the first mounting portion 43. The first sealing portion 71 is located between the two second sealing portions 72. When there is only one second sealing portion 72, the two ends of the first sealing portion 71 are located on opposite sides of the second sealing portion 72.

[0054] The sealing strip 7 also includes a third sealing portion 73, which is connected between the first sealing portion 71 and the adjacent second sealing portion 72. In the installed state, it is tightly fitted against the notch 421 of the air inlet ring 4 in the circumferential direction to further improve the sealing performance. The first sealing portion 71, the second sealing portion 72 and the third sealing portion 73 are preferably integrally formed.

[0055] The first sealing part 71 has a U-shaped cross-section. Here, "cross-section" refers to a plane passing through axis X, such as a vertical plane in the normal installation state (fan outlet facing upwards). The first sealing part 71 is engaged with the end of the inlet ring 4 located inside the volute 1 and near the impeller 2, i.e., the end of the guide part 42. The U-shaped opening faces outwards from the volute 1. In the installed state, it is pressed tightly against the outer circumferential surface of the frame 52 of the mesh cover 5. The second sealing part 72 is engaged with the first mounting part 43. When the mesh cover 5 slides to the locking position, the elastic deformation of the rubber fills and seals the sliding gap. This seal takes effect after installation and does not affect the sliding process.

[0056] The sealing effect requires sufficient strain. To generate sufficient sealing surface pressure This ensures a tight seal. However, this significantly increases friction during the sliding process. This affects the smoothness of the quick-release experience. Excessive sliding resistance is not ergonomic. Therefore, in this invention, under the constraints of ensuring the minimum surface pressure required for sealing and meeting the maximum permissible sliding resistance for comfortable human operation, a physical model is established and theoretical calculations are performed to determine key parameters (such as the original thickness of the sealing strip). () within a reasonable range.

[0057] The compression of the sealing strip 7 is simplified as a linear elastic model. The sealing surface pressure is generated by the compressive elastic force, and the sliding resistance mainly comes from the sliding friction between the sealing strip 7 and the mesh cover 5.

[0058] First, determine the key parameters for implementing the following functions:

[0059] 1.E: Elastic modulus (Pa) of sealing strip 7, determined by the material.

[0060] 2. : Sealing strip 7 compressive strain (Key design parameters here) Figure 10 The thickness of the second sealing part 72 is marked in the figure. The thickness of the third sealing part 73 is the same. The thickness of the first sealing part 71 can be considered only on the side that contacts the mesh cover 5.

[0061] 3.μ: The coefficient of sliding friction between the sealing strip 7 and the material (such as sprayed galvanized sheet) of the frame 52 of the mesh cover 5, which is determined by the material.

[0062] 4.L: The total effective contact length (m) of the sealing strip 7 is mainly determined by the diameter of the mesh cover 5 and the air inlet ring 4, and can be easily obtained through calculation or measurement.

[0063] 5.w: The average contact width (m) between the sealing strip 7 and the mesh cover 5 is preferably 2~12mm.

[0064] 6. When operating with one hand, the maximum thrust that feels comfortable is generally between 10N and 40N.

[0065] 7. Q: What is the rated maximum airflow (m³ / h) of the range hood? 3 / s).

[0066] 8.S: Area of ​​the 5 flow channels in the mesh cover (m²) 2 ), which is approximately the area of ​​the circle enclosed by the inner circumference of the mounting portion 41 of the air inlet ring 4.

[0067] 9. The combined tolerance zone width (mm) of the air inlet ring 4 and the sealing strip 7, for example, the tolerance is... ,but .

[0068] Then, the derivation logic and formulas for the reasonable range of the above parameters are as follows:

[0069] Objective 1: Ensure sealing: Requires pressure on the sealing surface. The pressure difference between the inside and outside of the air inlet ring is greater than 4. (Part of the fan's kinetic pressure depends on the range hood's air performance and can be estimated from the range hood's nominal maximum airflow.)

[0070]

[0071] Wind pressure coefficient (drag coefficient), dimensionless, for mesh cover 5, Option 1 is acceptable.

[0072] Air density, often simplified to 1.2 kg / m³ in actual estimations.

[0073] The surface pressure generated by sealing strip 7:

[0074] Sealing conditions: ,Right now:

[0075]

[0076] Where K is the safety factor, and considering the aging of the sealing gasket, it is preferably 3 to 5.

[0077] Objective 2: Control sliding resistance: Total sliding resistance Should be smaller Considering that there is a sealing strip 7 throughout the entire circumference, therefore:

[0078] Total normal pressure:

[0079] Total sliding friction (ignoring minor friction between the slider and the guide rail):

[0080] Operating force conditions: ,Right now:

[0081]

[0082] Solving for the dependent variable using simultaneous methods Feasible domain:

[0083] From this, we can obtain the dependent variable. The following conditions must be met simultaneously:

[0084]

[0085] This is the key parameter. The formula for the reasonable range.

[0086] Satisfy the following formula:

[0087]

[0088] Obviously, in order to make the tolerance zone within All satisfy the above relationships. The difference between the upper and lower limits should be greater than :

[0089]

[0090]

[0091] The following is a derivation example for a given parameter:

[0092] Assume the following parameter is known: Q = 30 m 3 / min=0.5 m 3 / s, S=0.034m 2 L = 0.65 m, w = 0.004 m, E = 0.02 MPa = 20000 Pa, K = 4, μ = 0.8 (dry rubber to galvanized sheet), =20N, .

[0093] Calculate the minimum dependent variable: = = 2.6%

[0094] Calculate the maximum dependent variable: = 20 ÷ ( (× 0.65 × 0.004) = 38.5%

[0095] Feasible region: 2.6% ≤ ≤ 38.5%.

[0096]

[0097] h needs to be greater than 2.8mm, but considering that h should not be too large at the four points of the air inlet ring, it is usually selected as... The thickness should be less than 5 mm to avoid an overly bulky structure. If the calculated thickness h is too high, it indicates that the current design... If E and w are unreasonable, adjustments are needed (such as choosing a softer sealing material to reduce E, or optimizing the sealing layout to reduce w).

Claims

1. A centrifugal fan, comprising: The volute (1) includes an air inlet (11); An air inlet ring (4) is provided at the air inlet (11); and A mesh cover (5) is installed on the air inlet ring (4) and covers the radially inner side of the air inlet ring (4); characterized in that: The air inlet ring (4) includes a first mounting part (43), and the mesh cover (5) includes a second mounting part (53) that is slidably installed into the first mounting part (43) along the axial direction of the centrifugal fan; The centrifugal fan also includes a sealing strip (7) disposed between the air inlet ring (4) and the mesh cover (5).

2. The centrifugal fan of claim 1, wherein: The air inlet ring (4) includes a mounting portion (41) installed on the outer periphery of the air inlet (11) and located on the outside of the volute (1) and a guide portion (42) extending from the inner periphery of the mounting portion (41) toward the impeller (2) inside the volute (1). The first mounting portion (43) is formed at the end of the guide portion (42) located inside the volute (1). The side of the first mounting portion (43) facing the inside of the volute (1) is open. A notch (421) is formed on the guide portion (42). The first mounting portion (43) communicates with the inner periphery of the guide portion (42) through the notch (421).

3. The centrifugal fan according to claim 2, characterized in that: The mesh cover (5) includes a mesh cover body (51) and a frame (52) formed on the outer periphery of the mesh cover body (51), and the second mounting part (53) is formed on the frame (52).

4. The centrifugal fan according to claim 3, characterized in that: The sealing strip (7) includes a first sealing part (71), a second sealing part (72) and a third sealing part (73). The first sealing part (71) is engaged with the end of the guide part (42) located inside the volute (1) and thus partially pressed between the guide part (42) and the frame (52) of the mesh cover (5). The second sealing part (72) is pressed between the first mounting part (43) and the second mounting part (53). The third sealing part (73) is connected between the first sealing part (71) and the adjacent second sealing part (72). The third sealing part (73) is close to the notch (421) of the air inlet ring (4) in the circumferential direction.

5. The centrifugal fan according to any one of claims 1 to 4, characterized in that: The first mounting part (43) and the second mounting part (53) are magnetically attached.

6. The centrifugal fan according to any one of claims 1 to 4, characterized in that: A locking mechanism (6) is movably provided on the first mounting part (43), and a slot (531) is provided on the second mounting part (53). The locking mechanism (6) tends to be engaged in the slot (531).

7. A range hood, characterized in that: The application uses a centrifugal fan as described in any one of claims 1 to 6.

8. The range hood according to claim 7, characterized in that: The sealing strip (7) is a rubber strip, and the compressive strain of the sealing strip (7) is... satisfy: Where K is the safety factor. The elastic modulus of the sealing strip (7) is... The pressure coefficient of the airflow passing through the centrifugal fan. Where is the air density, Q is the nominal maximum air volume of the range hood, and S is the flow area at the mesh cover (5). The maximum thrust is the one-handed operation of the mesh cover (5) to feel comfortable. L is the total effective contact length of the sealing strip (7) and w is the average contact width between the sealing strip (7) and the mesh cover (5).

9. The range hood according to claim 8, characterized in that: The original thickness of the sealing strip (7) satisfies h: in, K represents the combined tolerance zone width of the air inlet ring (4) and the sealing strip (7), where K is the safety factor of the sealing strip (7). for The maximum value, for The minimum value.

10. The range hood according to claim 7, characterized in that: The air inlet (11) of the volute (1) faces the wall where the range hood is installed.

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