Fume hoods and range hoods

Abstract

The present invention provides a smoke hood and a range hood, and relates to the technical field of kitchen appliances. A guide block is arranged on the top wall of the smoke hood, and the guide block is arranged on the inner side of the top wall. The distance between the side surface of the guide block away from the top wall and the inner wall of the top wall is not less than the distance that the reinforcement part protrudes relative to the inner wall of the top wall. The present invention improves the flow field of the airflow through the guide block arranged therein, shortens the flow path of the airflow, and reduces the possibility of the airflow generating vortex at the reinforcement part position, thereby reducing the aerodynamic noise and improving the noise environment of the range hood when absorbing and exhausting oil smoke.

Description

Technical Field

[0001] The invention relates to the technical field of kitchen appliances, and in particular to a fume hood and a range hood. Background Art

[0002] Range hoods, also known as range hoods, smoke machines or extractor hoods, are common equipment for extracting and exhausting oil fumes in modern kitchens. The internal structure of existing range hoods causes changes in the oil fume path, requiring multiple changes in the flow path, resulting in a longer airflow path, worse flow conditions, and increased noise. Especially in the European-style range hood, the smoke collection chamber and the chassis connection area, such as Figure 1 As shown, the smoke collecting chamber 3' is provided with a circle of raised structures 1' near the entrance of the chassis 2', in order to increase the strength and connection reliability. However, the pressed raised structures 1' deteriorate the airflow state from the smoke collecting chamber 3' into the chassis 2'. Figure 2 As shown, due to the presence of the step formed by the raised structure 1', when the airflow formed by the oil smoke enters the smoke collecting chamber 3' of the smoke hood from the air inlet oil net 4' and then flows to the chassis 2' through the raised structure 1', the flow direction of the airflow will be changed, causing the airflow to tilt downward, the flow path of the airflow entering the chassis 2' will become longer, the flow state will deteriorate, and the noise will increase. Summary of the invention

[0003] The object of the present invention is to provide an air collecting hood and a range hood to solve the technical problem in the prior art that a smoke collecting chamber structure is provided with a circle of raised structures near the entrance of the chassis, which increases the movement path of the oil smoke and easily generates noise.

[0004] The smoke hood provided by the present invention is used to be connected to the chassis of a range hood, and the top wall of the smoke hood is provided with a reinforcement portion protruding toward the chassis, and the inner wall of the top wall is provided with a guide block, and the distance between the bottom surface of the guide block away from the top wall and the inner wall of the top wall is not less than the distance that the reinforcement portion protrudes relative to the inner wall of the top wall.

[0005] Furthermore, the guide block is arranged on a side of the reinforcement portion away from the chassis.

[0006] Furthermore, the guide block is provided in the form of a box body, and a plurality of silencer holes are provided on the bottom surface of the guide block away from the top wall.

[0007] Furthermore, the guide block is provided in the form of a box, and a sound absorbing structure is provided inside the guide block.

[0008] Furthermore, the circumferential side surface of the guide block is provided with an opening.

[0009] Further, the opening is arranged at one end of the guide block close to the chassis;

[0010] or;

[0011] The openings are arranged on two opposite side surfaces of the guide block.

[0012] The range hood provided by the present invention comprises a chassis and the fume collecting hood provided by the present invention, wherein the chassis is fixedly connected to the top wall of the fume collecting hood.

[0013] Furthermore, the range hood further comprises a fan mechanism, the fan mechanism is installed in the chassis, the fan mechanism comprises a volute, and a first air inlet and a second air inlet are respectively formed on the left and right sides of the volute;

[0014] An air guide mechanism is provided below the volute, and the air guide mechanism is formed with a first air guide surface and a second air guide surface. The first air guide surface is used to guide the oil fume airflow to the first air inlet, and the second air guide surface is used to guide the oil fume airflow to the second air inlet.

[0015] Furthermore, the air guide mechanism is arranged in a "V" shape, including a first air guide plate and a second air guide plate, the lower ends of the first air guide plate and the second air guide plate are fixedly connected, the upper end of the first air guide plate is fixedly connected to the bottom of the volute on the side corresponding to the first air inlet, the side of the first air guide plate away from the second air guide plate forms a first air guide surface, the upper end of the second air guide plate is fixedly connected to the bottom of the volute on the side corresponding to the second air inlet, and the side of the second air guide plate away from the first air guide plate forms the second air guide surface.

[0016] Furthermore, the air guide mechanism is fixed on the bottom of the volute, and the distance between one end of the air guide mechanism away from the volute and the bottom of the volute is not less than 50 mm and not greater than the length between the inlet of the chassis and the bottom of the volute.

[0017] Furthermore, a first rectifying net is arranged on the inlet of the chassis, and the air guide mechanism is arranged above the first rectifying net;

[0018] and / or

[0019] A second rectifier network is provided between the volute and the chassis, corresponding to the first air inlet and the second air inlet;

[0020] and / or

[0021] A third rectifying net is disposed on the first air inlet and the second air inlet.

[0022] Furthermore, a second rectifying net is provided between the volute and the chassis, corresponding to the first air inlet and the second air inlet;

[0023] An angle A between the first air guide surface and the second rectifying net on the corresponding side thereof is not greater than 180 degrees, so that the second rectifying net is spaced apart from the first air inlet of the volute, and the angle A is not less than the first reference angle; an angle A1 is formed between a line L1 connecting the bottom of the edge of the volute corresponding to the first air inlet and the lower edge of the side wall on the corresponding side of the chassis, and a plane L2 where the first air guide surface is located when the end of the air guide mechanism away from the volute is in the highest state that can be set; an angle A2 is formed between a line L3 connecting the lower edge of the first air inlet and the lower edge of the side wall on the corresponding side of the chassis, and a line L4 connecting the bottom of the edge of the volute corresponding to the first air inlet and the center of the inlet of the chassis; the first reference angle is the smaller of the angles A1 and A2;

[0024] An angle B between the second air-guiding surface and the second rectifying net on the corresponding side is not greater than 180 degrees, so that the second rectifying net is spaced from the second air inlet of the volute, and the angle B is not less than a second reference angle; an angle B1 is formed between a line L5 connecting the bottom of the edge of the volute corresponding to the second air inlet and the lower edge of the side wall on the corresponding side of the chassis, and a plane L6 on which the second air-guiding surface is located when the end of the air-guiding mechanism away from the volute is in the highest state that can be set; an angle B2 is formed between a line L7 connecting the lower edge of the second air inlet and the lower edge of the side wall on the corresponding side of the chassis, and a line L8 connecting the bottom of the edge of the volute corresponding to the second air inlet and the center of the inlet of the chassis; the second reference angle is the smaller of the angles B1 and B2.

[0025] Furthermore, the second rectifying net is provided with a connecting portion, the second rectifying net is connected to the volute through the connecting portion, and the connecting portion is provided with mesh holes or both sides of the connecting portion are isolated;

[0026] And / or, the second rectifying network is connected to the inner walls of the front and rear sides of the chassis;

[0027] And / or, the angle A is between 70° and 180°, and the angle B is between 60° and 180°;

[0028] And / or, the second rectifying network is in a curved shape.

[0029] Furthermore, a first rectifying network is arranged on the inlet of the chassis, and the first rectifying network is arranged parallel to the inlet of the chassis;

[0030] A second rectifying net is provided between the volute and the chassis, corresponding to the first air inlet and the second air inlet, respectively. The first rectifying net and the second rectifying net are integrally formed, and / or the second rectifying net and the air guide mechanism are integrally formed.

[0031] Furthermore, meshes of the first rectifying net, the second rectifying net and / or the third rectifying net are hexagonal.

[0032] Furthermore, an air outlet hood is connected to the chassis, the air outlet hood is communicated with the air outlet of the volute, and the air outlet hood is inclined toward the volute tongue side of the volute relative to the top of the chassis.

[0033] Furthermore, the angle between the side wall of the air outlet cover away from the volute tongue and the extension line of the side of the air outlet of the volute away from the volute tongue is 0 degrees to 10 degrees;

[0034] The angle between the side wall of the air outlet cover close to the volute tongue and the inner side surface of the volute tongue is greater than the sum of the volute tongue inclination angle and 90 degrees, and is not greater than 180 degrees.

[0035] Furthermore, a connecting valve is provided on the air outlet of the air outlet hood, and the connecting valve is inclined gradually towards the chassis from a side away from the volute tongue to a side close to the volute tongue, and an inclination angle of the connecting valve relative to the plane where the top of the chassis is located is 5 to 15 degrees.

[0036] The smoke collecting hood provided by the present invention is used to be connected with the chassis of the range hood, and the top wall of the smoke collecting hood is provided with a reinforcement part protruding in the direction of the chassis, and the inner wall of the top wall is provided with a guide block, and the distance between the side of the guide block away from the top wall and the inner wall of the top wall is not less than the distance that the reinforcement part protrudes relative to the inner wall of the top wall. When the airflow formed by the smoke enters the smoke collecting hood from the smoke inlet of the smoke collecting hood, it flows to the entrance of the chassis along the surface of the guide block facing the smoke inlet. Since the distance between the bottom surface of the guide block away from the top wall, that is, the surface of the guide block facing the smoke inlet, and the inner wall of the top wall is not less than the distance that the reinforcement part protrudes relative to the inner wall of the top wall, the airflow will not be blocked and change its flow direction when passing through the reinforcement part, and the airflow smoothly enters the chassis along the guide block. The smoke collecting hood of the present invention improves the flow field of the airflow through the guide block provided therein, shortens the flow path of the airflow, and reduces the possibility of the airflow generating vortex at the position of the reinforcement part, thereby reducing the aerodynamic noise and improving the noise environment of the range hood when absorbing and exhausting oil smoke.

[0037] The range hood provided by the present invention comprises a chassis and a fume hood provided by the present invention, wherein the chassis is fixedly connected to the top wall of the fume hood. The range hood provided by the present invention has the same beneficial effects as the fume hood provided by the present invention, which will not be described in detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of the connection position between the smoke hood and the chassis in the prior art;

[0040] Figure 2 It is a schematic diagram of the airflow in the smoke collecting cavity of the smoke collecting hood in the prior art;

[0041] Figure 3 A schematic diagram of airflow in a smoke collecting chamber of a smoke collecting hood provided in an embodiment of the present invention;

[0042] Figure 4 A schematic cross-sectional view of a smoke collecting chamber of a smoke collecting hood provided by an embodiment of the present invention from left to right;

[0043] Figure 5 A schematic cross-sectional view of a smoke collecting chamber of a smoke collecting hood provided in an embodiment of the present invention along a front-to-back direction;

[0044] Figure 6 A schematic diagram of the internal structure of a chassis of a range hood provided in an embodiment of the present invention;

[0045] Figure 7 A partial cross-sectional isometric schematic diagram of a range hood provided in an embodiment of the present invention;

[0046] Figure 8 A schematic cross-sectional isometric view of a range hood provided in an embodiment of the present invention;

[0047] Fig. 9 for Figure 8 The main view of

[0048] Fig.10 for Fig. 9 A partial schematic diagram of

[0049] Fig.11 A schematic diagram of an air outlet cover of a range hood provided by an embodiment of the present invention at one angle;

[0050] Fig.12 A schematic diagram of an air outlet cover of a range hood provided by an embodiment of the present invention at another angle;

[0051] Fig.13 A schematic diagram of the installation of a second rectifying network of a range hood provided by an embodiment of the present invention;

[0052] Fig.14 A schematic diagram of the maximum installation angle of the second rectifying network of the range hood provided by an embodiment of the present invention;

[0053] Fig.15 A schematic diagram of the minimum installation angle of the second rectifying network of the range hood provided by an embodiment of the present invention;

[0054] Fig.16 A schematic diagram of a second rectifying network on the left side of a range hood provided by an embodiment of the present invention;

[0055] Fig.17 A schematic diagram of a second rectifying network on the right side of a range hood provided by an embodiment of the present invention;

[0056] Fig.18 A schematic diagram of a first rectifying network of a range hood provided by an embodiment of the present invention;

[0057] Fig.19 A comparison diagram of airflow directions of a range hood with and without a guide block installed provided by an embodiment of the present invention;

[0058] Fig. 20 A comparison diagram of airflow directions of a range hood provided by an embodiment of the present invention with an air guide mechanism installed and without an air guide mechanism installed;

[0059] Fig.21 A comparison diagram of airflow directions when the air outlet hood of the range hood provided by an embodiment of the present invention is in a tilted and non-tilted state.

[0060] Icons: 1'-raised mechanism; 2'-chassis; 3'-smoke collecting chamber; 4'-oil inlet net; 2-chassis; 3-smoke collecting chamber; 4-oil inlet net; 100-smoke collecting hood; 110-guide block; 111-opening; 112-connecting section; 120-reinforcement part; 300-fan mechanism; 301-volute; 302-volute tongue; 3011-side; 3012-inner side; 400-air guiding mechanism; 401-first air guiding surface; 402-second air guiding surface; 410-first air guiding plate; 420-second air guiding plate; 510-first rectifying net; 520-second rectifying net; 521-connecting part; 530-third rectifying net; 600-air outlet hood; 601-one side wall; 602-one side wall; 610-connecting valve; 700-air outlet pipe. DETAILED DESCRIPTION

[0061] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] Example

[0063] like Figure 3 to Figure 21 As shown, this embodiment provides a fume hood 100 for connecting to the chassis 2 of the range hood. The top wall of the fume hood 100 is provided with a reinforcing portion 120 protruding toward the chassis 2, that is, the reinforcing portion 120 protrudes on the side of the top wall of the fume hood 100 close to the chassis 2 and facing the smoke inlet of the fume hood 100. A guide block 110 is also provided on the top wall, and the guide block 110 is arranged on the inner side of the top wall and on the side of the reinforcing portion 120 away from the chassis 2, and the distance h2 between the side of the guide block 110 away from the top wall and the inner wall of the top wall is not less than the distance h1 that the reinforcing portion 120 protrudes relative to the inner wall of the top wall.

[0064] The smoke inlet of the smoke hood 100 of this embodiment is usually provided with an oil inlet net 4. The smoke hood 100 of this embodiment is mainly aimed at improving the problem that the existing smoke hood 100 is provided with a reinforcement part 120 near the chassis 2, which affects the airflow and causes a large noise. The reinforcement part 120 can be understood as a convex structure of the existing smoke hood 100. The side of the guide block 110 away from the top wall is the bottom surface of the side of the guide block 110 facing the smoke inlet of the smoke hood 100, that is, Figure 3 The distance h2 between the side of the guide block 110 away from the top wall and the inner wall of the top wall is not less than the distance h1 of the reinforcement portion 120 protruding relative to the inner wall of the top wall, that is, Figure 3 As shown, the guide block 110 is flush with the lower surface of the reinforcement part 120, or the lower surface of the guide block 110 is more protruding downward relative to the lower surface of the reinforcement part 120. The guide block 110 is usually arranged between the side wall of the smoke hood 100 and the reinforcement part 120, and preferably, the lower surface of the guide block 110 is a plane, which can be arranged parallel to the top wall to make the airflow formed by the smoke flow smoothly.

[0065] contrast Fig.19 It can be seen from a and b that the airflow in the smoke hood 100 of this embodiment flows more gently. Specifically, Fig.19 b represents a flow diagram of the airflow without the guide block 110. It can be seen that in the D1 area close to the top wall, the airflow will change direction downward at the reinforcement portion 120, and then enter the chassis 2. The flow path of the airflow becomes longer and it is easy to generate vortices in the D2 area. Fig.19The flow diagram of the airflow in the present embodiment with the guide block 110 is represented by a. When the smoke hood 100 of the present embodiment is in use, the airflow formed by the smoke enters the smoke hood 100 from the smoke inlet of the smoke hood 100, and flows along the surface of the guide block 110 facing the smoke inlet to the entrance of the chassis 2. Since the distance between the side of the guide block 110 away from the top wall, that is, the surface of the guide block 110 facing the smoke inlet, and the inner wall of the top wall is not less than the distance of the reinforcement 120 protruding relative to the inner wall of the top wall, the airflow will not be blocked and change its flow direction when passing through the reinforcement 120, and the airflow smoothly enters the chassis 2 along the guide block 110 in the D1 area. The smoke hood 100 of the present embodiment improves the flow field of the airflow through the guide block 110 provided therein, shortens the flow path of the airflow, and reduces the possibility of the airflow generating vortex at the position of the reinforcement 120, thereby reducing the aerodynamic noise and improving the noise environment of the range hood when absorbing and exhausting oil smoke.

[0066] Furthermore, in order to improve the noise reduction effect, the guide block 110 of this embodiment is provided in a box body, and a plurality of silencer holes are provided on the side of the guide block 110 away from the top wall, that is, on the lower surface of the guide block 110. The silencer holes are generally a plurality of dense micro-holes. The aerodynamic noise generated by the airflow can be transmitted to the box body of the guide block 110 through the silencer holes, and reflected inside the box body, consuming sound energy and reducing noise.

[0067] It should be noted that, in this embodiment, the guide block 110 may only include a bottom wall and a side wall, and the side wall of the guide block 110 is connected to the inner side of the top wall of the smoke hood 100, that is, the guide block 110 and the inner wall of the smoke hood 100 together form a box body.

[0068] Furthermore, the circumferential side of the guide block 110 may be provided with an opening 111, and the opening 111 is connected to the smoke collecting chamber 3. Specifically, the opening may be provided at one end of the guide block 110 close to the chassis, or the opening may be provided on two opposite sides of the guide block 110. Figure 4 and Figure 5 As shown, the guide block 110 is roughly arranged in a rectangular shape, and the openings 111 are arranged on the left and right sides of the guide block 110; the front and rear sides of the guide block 110 are sealed and connected to the bottom surface, and the upper ends of the left and right sides of the side surfaces are provided with connecting sections 112, and the connecting sections 112 are fixedly connected to the inner wall of the smoke hood 100.

[0069] It should be noted that Figure 7 The direction indicated by the arrow D is from left to right. Figure 7 The direction indicated by the arrow E is from front to back.

[0070] Meanwhile, in this embodiment, a sound-absorbing structure can be provided in the guide block 110 to further achieve the noise reduction effect. Specifically, a sound-absorbing material is provided in the box body of the guide block 110, and the sound-absorbing material can be a sound-absorbing cotton, which can further absorb noise.

[0071] The present embodiment further provides a range hood, comprising a chassis 2 and a fume hood 100 provided in the present embodiment, wherein the chassis 2 is fixedly connected and communicated with a top wall of the fume hood 100 .

[0072] The range hood further includes a fan mechanism 300, which is installed in the chassis 2. The fan mechanism 300 includes a volute 301, and a first air inlet and a second air inlet are formed on the left and right sides of the volute 301, respectively. An air guide mechanism 400 is provided below the volute 301, and the air guide mechanism 400 includes a first air guide surface 401 and a second air guide surface 402. The first air guide surface 401 is used to guide the oil smoke airflow to the first air inlet, and the second air guide surface 402 is used to guide the oil smoke airflow to the second air inlet.

[0073] It should be noted that the fan mechanism 300 is an existing conventional fan mechanism 300, which also includes an impeller installed in the volute 301 and a motor that drives the impeller to rotate.

[0074] Specifically, Figure 8 to Figure 10 As shown, the air guide mechanism 400 of this embodiment is arranged in a V shape, including a first air guide plate 410 and a second air guide plate 420, the lower ends of the first air guide plate 410 and the second air guide plate 420 are fixedly connected, that is, the V-shaped vertex end of the air guide mechanism 400 is the lower end of the first air guide plate 410 and the second air guide plate 420, and the first air guide plate 410 and the second air guide plate 420 are connected in a V shape. The upper end of the first air guide plate 410 is fixedly connected to the bottom of the volute 301 corresponding to the first air inlet side, the upper end of the second air guide plate 420 is fixedly connected to the bottom of the volute 301 corresponding to the second air inlet side, the side of the first air guide plate 410 away from the second air guide plate 420 forms a first air guide surface 401, and the side of the second air guide plate 420 away from the first air guide plate 410 forms a second air guide surface 402.

[0075] It is understandable that the air guide mechanism 400 should have a certain height to have a better air guide effect. In this embodiment, the air guide mechanism 400 is fixed to the bottom of the volute 301, and the distance between the end of the air guide mechanism 400 away from the volute 301 and the bottom of the volute 301 is not less than 50 mm, that is, Fig.13As shown, the minimum length H1 of the V-shaped apex of the air guide mechanism 400 from the bottom of the volute 301 is 50 mm. At the same time, the maximum distance between the V-shaped apex of the air guide mechanism 400 and the bottom of the volute 301 is no greater than the length H2 between the air inlet of the chassis 2 and the bottom of the volute 301, that is, the V-shaped apex of the air guide mechanism 400 is located on the inner side of the air inlet of the chassis 2 to avoid protruding to the outer side of the air inlet of the chassis 2. Preferably, in this embodiment, the distance between the end of the air guide mechanism 400 away from the volute 301 and the bottom of the volute 301 is 65 mm. Figure 13 to Figure 15 W in the figure represents the center line of the volute 301 in the vertical direction, which is also the center line of the air guide mechanism 400.

[0076] contrast Fig. 20 It can be seen from a and b that the range hood of this embodiment is more conducive to the smooth flow of air by setting the air guide mechanism 400. Specifically, Fig. 20 A is a schematic diagram of air flow without the air guide mechanism 400 installed. It can be seen that after the airflow enters the chassis 2, the flow at the bottom of the volute 301 interferes with each other seriously, which is not conducive to the flow of airflow. The interfering flow of the airflow is also prone to generate aerodynamic noise. Fig. 20 FIG. 1 b shows a schematic diagram of the air flow after the range hood of this embodiment is provided with an air guide mechanism 400. It can be seen that after the air flow enters the chassis 2, it is distributed to both sides of the volute 301 under the action of the air guide mechanism 400 to flow toward the first air inlet and the second air inlet. The interference between the air flows is reduced, the air flow field is improved, the flow is smoother, and the aerodynamic noise generated by the air flow is reduced.

[0077] In order to further reduce the noise of the range hood when it is sucking and exhausting oil smoke, the range hood of this embodiment also improves the air outlet hood 600 connected to the chassis 2. Specifically, the upper end of the chassis 2 is fixedly connected with the air outlet hood 600, and the air outlet hood 600 is connected to the air outlet of the volute 301. The air outlet hood 600 is inclined relative to the top of the chassis 2 and faces the volute tongue 302 side of the volute 301. In one implementation, Fig.11As shown, the circumferential side walls of the air hood 600 are all inclined toward the side of the volute tongue 302, and the air outlet of the air hood is parallel to the top of the chassis 2. It can be understood that when the volute 301 of the range hood is installed, according to the line direction of the volute 301, the side 3011 of the air outlet of the volute 301 away from the volute tongue 302 is usually inclined, and the inclination angle is about 10 degrees; the volute tongue 302 is also inclined, and the inclination angle of the volute tongue 302 relative to the plane where the top of the chassis 2 is located is about 20 degrees to 30 degrees. Therefore, the air hood 600 is inclined toward the side of the volute tongue 302, which conforms to the air flow direction of the air outlet of the volute 301. Compared with the air hood 600 vertically arranged on the top of the chassis 2, it can avoid the airflow flowing out of the air outlet of the volute 301 to a certain extent. Interference and aerodynamic noise at the position of the air hood 600 or the position of the air outlet pipe 700.

[0078] The angle between the side wall 601 of the air outlet hood 600 away from the volute tongue 302 and the extension line of the side 3011 of the air outlet of the volute 301 away from the volute tongue 302 is 0 to 10 degrees. The side wall 601 of the air outlet hood 600 away from the volute tongue 302 can be set on the side of the extension line of the side 3011 away from the volute tongue 302, or on the side close to the volute tongue 302. The specific angle can be 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 8 degrees or 10 degrees; the side wall 601 of the air outlet hood 600 away from the volute tongue 302 can also coincide with the extension line of the side 3011, that is, the angle is 0 degrees. Preferably, it is 0 degrees, that is, as Fig.11 As shown, the angle α of the side wall 601 of the air outlet hood 600 away from the volute tongue 302 relative to the vertical direction is the same as the angle of inclination of the side surface 3011 relative to the vertical direction, that is, the angle α is 10°, so that the side wall 601 of the air outlet hood 600 away from the volute tongue 302 is approximately parallel to the side surface 3011 of the volute casing 301 where the air outlet is away from the volute tongue 302.

[0079] The angle β between the side wall 602 of the air outlet cover 600 close to the volute tongue 302 and the inner side surface 3012 of the volute tongue 302 is greater than the volute tongue inclination angle (the inclination angle of the volute tongue 302 relative to the plane where the top of the chassis 2 is located is the volute tongue inclination angle), that is, Fig.11 The sum of the angle C shown and 90 degrees is not greater than 180 degrees, that is, the side wall 602 of the air outlet cover 600 close to the volute tongue 302 has a certain inclination angle relative to the plane where the top of the chassis 2 is located, facing the side where the volute tongue 302 is located. Since the inclination angle of the volute tongue is usually about 20 to 30 degrees, the angle β is usually between 120 and 180 degrees, and can be 130, 140, 150, 160, 165, 175 or 180 degrees, preferably 180 degrees. Fig.11In the figure, the angle β between the side wall 602 of the air outlet cover 600 close to the volute tongue 302 and the inner side surface 3012 of the volute tongue 302 is represented as β1, and β1 is 165°. The air outlet of the air outlet cover is parallel to the top of the chassis 2, and the angle γ1 between the side wall 602 of the air outlet cover 600 close to the volute tongue 302 and the pipe wall of the air outlet pipe 700 is 150°.

[0080] But if Fig.11 The air outlet of the air hood is parallel to the top of the chassis 2, that is, the end of the air outlet of the air hood 600 connected to the air outlet pipe 700 is horizontal. At this time, the airflow leaving the air hood 600 will form a low-speed zone on the side of the air outlet pipe 700 away from the volute tongue 302, that is, within the range of the angle α1, and easily form a vortex; and the airflow impacts the air outlet pipe 700 (at the angle γ1 position) and the air hood 600 (at the angle β1 position) near the volute tongue 302, causing impact noise. In order to improve the impact noise problem at the position of the air hood 600, as shown in FIG. Fig.12 As shown, in a further improved solution of this embodiment, the air outlet of the air outlet cover is inclined relative to the top wall of the chassis 2 and faces the side of the volute tongue 302. Specifically, a connecting valve 610 is provided on the air outlet of the air outlet cover 600, and the connecting valve 610 extends from the side away from the volute tongue 302 to the side close to the volute tongue 302 ( Fig.12 As shown, from left to right) the connecting valve 610 is gradually tilted towards the chassis 2, and the inclination angle of the connecting valve 610 relative to the plane where the top of the chassis 2 is located is 5 to 15 degrees, that is, the connecting valve 610 of the air outlet hood is tilted relative to the top wall of the chassis 2, that is, the horizontal direction, and the inclination angle θ1 can be 5° to 15°, preferably 10°.

[0081] like Fig.12As shown, the connecting valve 610 of the air outlet of the air outlet hood of the range hood of this embodiment is inclined toward the side of the volute tongue 302, and the airflow leaving the air outlet hood 600 flows along the original path on the side of the air outlet pipe 700 away from the volute tongue 302. There is no low-speed area, no vortex is generated, and the flow condition is good. In addition, since the caliber of the air outlet hood 600 is generally gradually enlarged along the flow direction of the airflow, and the inclination of the side wall 601 of the air outlet hood away from the volute tongue does not change, in order to maintain the original caliber unchanged after the air outlet of the air outlet hood is tilted, the side wall 602 of the air outlet hood 600 close to the volute tongue 302 needs to be tilted closer to the top wall of the chassis 2, so that when the air outlet of the air outlet hood is tilted toward the volute tongue 302, the angle γ2 of the airflow impacting the air outlet duct 700 on the side close to the volute tongue 302 is not only larger than the angle γ1, but also the angle β2 of the airflow flowing out of the fan volute tongue 302 impacting the air outlet hood 600 is also larger than the angle β1, and the impact degree is reduced. It can be seen from this that the flow state of the airflow flowing through the air outlet hood 600 into the air outlet duct 700 is significantly improved, the impact noise is reduced, the low-speed flow area is eliminated, the vortex is eliminated, and the aerodynamic noise is reduced; at the same time, the fan mechanism 300 obtains a better pressure diffusion effect, which is helpful to improve the static pressure.

[0082] Fig.21 The figure shows the comparison of the air flow state of the range hood when the air hood 600 is tilted and when it is not tilted. It can be seen from the comparison that the air flow field of the range hood when the air hood 600 is tilted and the air outlet of the air hood is tilted is more stable. Fig.21 The state shown in a is that the air outlet cover 600 is not tilted and the connecting valve 610 of the air outlet cover is not tilted. In the D3 area, the airflow impacts the air outlet cover 600, which is likely to cause a large noise. Fig.21 FIG. b shows a state where the air outlet cover 600 and the connecting valve 610 are tilted, and the airflow flows smoothly in the D3 region, thereby avoiding the generation of impact noise.

[0083] It should be noted that the connecting valve 610 can be a structure fixed as one body with the air outlet cover 600, that is, the connecting valve 610 is a structure of the air outlet of the air outlet cover 600. The connecting valve 610 can also be a part of the air outlet pipe 700 used to connect with the air outlet cover, that is, the connecting valve is connected to the air outlet cover 600 as one body.

[0084] Furthermore, the range hood of this embodiment is also provided with a rectifying net, so as to achieve the purpose of noise reduction by rectifying the airflow through the rectifying net. Specifically, a first rectifying net 510 can be provided on the air inlet of the chassis 2. It should be noted that the air guide mechanism 400 is provided above the first rectifying net 510. A second rectifying net 520 can also be provided between the volute 301 and the chassis 2, corresponding to the sides where the first air inlet and the second air inlet are located. A third rectifying net 530 can also be provided on both the first air inlet and the second air inlet.

[0085] It should be noted that the first rectifying network 510, the second rectifying network 520 and the third rectifying network 530 can be set one by one or at the same time. When they are set at the same time, the rectification and noise reduction effect is the best. This embodiment is mainly described by taking the first rectifying network 510, the second rectifying network 520 and the third rectifying network 530 being set at the same time as an example.

[0086] The first rectifying net 510 is arranged parallel to the air inlet of the chassis 2. The second rectifying net 520 and the first rectifying net 510 can be an integral structure, that is, the first rectifying net 510 and the second rectifying net 520 are formed by bending the entire rectifying net, and the entire rectifying net is arranged between the inner wall of the chassis 2 and the volute 301. The shape of the third rectifying net 530 matches the shape of the first air inlet and the second air inlet.

[0087] The second rectifying net 520 of the range hood of this embodiment should be arranged at a distance from the first rectifying net 510 and the third rectifying net 530, so that the airflow can have a better rectifying effect after passing through the first rectifying net 510, the second rectifying net 520 and the third rectifying net 530. The arrangement positions of the first rectifying net 510 and the third rectifying net 530 are usually fixed, and this embodiment will not introduce them in detail. The installation range of the second rectifying net 520 is relatively wide. This embodiment provides an optimal installation position for the relative relationship between the second rectifying net 520 and the air guide mechanism 400.

[0088] like Fig.14 As shown, the angle A between the first air guide surface 401 and the second rectifying net 520 on its corresponding side is not greater than 180 degrees, so that the second rectifying net 520 is spaced apart from the first air inlet of the volute 301. Fig.15 As shown, the angle A is not less than the first reference angle. The line L1 connecting the bottom of the edge of the volute 301 corresponding to the first air inlet and the lower edge of the side wall of the corresponding side of the chassis 2 and the end of the air guide mechanism 400 away from the volute 301 is in the highest state that can be set (that is, Fig.15 The apex angle end of the V-shape of the air-guiding mechanism 400 shown is at a distance from the bottom of the volute 301, and forms an angle A1 with the plane L2 where the first air-guiding surface 401 is located when the first air-guiding surface 401 is in a state of minimum length H1; an angle A2 is formed between a line L3 connecting the lower edge of the first air inlet and the lower edge of the side wall on the corresponding side of the chassis 2, and a line L4 connecting the bottom of the edge of the volute 301 on the side corresponding to the first air inlet and the center of the air inlet of the chassis 2; the first reference angle is the smaller one of the angles A1 and A2.

[0089] like Fig.14 As shown, the angle B between the second air guide surface 402 and the second rectifying net 520 on its corresponding side is not greater than 180 degrees, so that the second rectifying net 520 is spaced apart from the second air inlet of the volute 301. Fig.15 As shown, the angle B is not less than the second reference angle. The line L5 connecting the bottom of the edge of the volute 301 corresponding to the second air inlet and the lower edge of the side wall of the corresponding side of the chassis 2 and the end of the air guide mechanism 400 away from the volute 301 is in the highest state that can be set (that is, Fig.15 The V-shaped top angle end of the air guide mechanism 400 shown is at the minimum length H1 from the bottom of the volute 301, and the plane L6 where the second air guide surface 402 is located forms an angle B1; the line L7 connecting the lower edge of the second air inlet and the lower edge of the side wall on the corresponding side of the chassis 2, and the line L8 connecting the bottom of the edge of the volute 301 on the side corresponding to the second air inlet and the center of the air inlet of the chassis 2 forms an angle B2. The second reference angle is the smaller of the angles B1 and B2.

[0090] Usually, due to factors such as the space occupied by the motor of the fan mechanism 300, the fan mechanism 300 is set to one side of the chassis 2. For example, in this embodiment, the fan mechanism 300 is set to the right side, so that the gap formed by the chassis 2 on the side of the first air inlet is larger than the gap formed by the chassis 2 on the side of the second air inlet. Therefore, the air intake of the first air inlet is often larger than the air intake of the second air inlet. The first air inlet is also the main air inlet, and the second air inlet is also the auxiliary air inlet. Similarly, due to the difference in the gaps on the left and right sides of the fan mechanism 300, the minimum values ​​of the angle A between the first air guide surface 401 and the second rectifier network 520 on its corresponding side and the angle B between the second air guide surface 402 and the second rectifier network 520 on its corresponding side are also different. Usually, the angle A1 and the angle A2 are both less than 70 degrees, and preferably, the angle A is between 70 degrees and 180 degrees; usually, the angle B1 and the angle B2 are both less than 60 degrees, and preferably, the angle B is between 60 degrees and 180 degrees. In this embodiment, if Fig.13 As shown, angle A is 110° and angle B is 100°.

[0091] It can be understood that the relative position relationship between the air guide mechanism 400 and the second rectifying net 520 of the range hood of this embodiment is such that the second rectifying net 520 always maintains an appropriate distance from the first rectifying net 510 and the third rectifying net 530, so that the first rectifying net 510, the second rectifying net 520 and the third rectifying net 530 can all play a role in rectifying the airflow, and there is no need to set up additional redundant rectifying nets, thereby saving resources and simplifying equipment.

[0092] Furthermore, since there is a gap between the air guide mechanism 400, the fan mechanism 300 and the front and rear of the chassis 2, during the operation of the range hood, airflow will be exchanged through the gap. The second rectifying net 520 is preferably connected to the inner wall of the front and rear sides of the chassis 2. At this time, due to the addition of the second rectifying net 520, a relatively closed area can be formed, which can reflect noise in its internal space and consume sound energy. Secondly, it can also play a role in straightening the airflow when the airflow passes through.

[0093] In a further solution, a connection portion 521 may be provided on the second rectifying net 520, and the second rectifying net 520 is connected to the volute 301 through the connection portion 521, and the connection portion 521 is connected between the inner walls of the front and rear sides of the chassis 2, and a mesh may be provided on the connection portion 521. At this time, the airflow entering the second rectifying net 520 and the first air inlet or the second air inlet of the volute 301 can also flow into the position where the air guide mechanism 400 is located through the mesh on the connection portion 521, which helps to balance the air pressure on both sides and helps to flow out through the other side when there is more airflow on one side. The connection portion 521 may not be provided with a mesh, that is, the two sides of the connection portion 521 are isolated, and the air intake on both sides of the fan mechanism 300 is completely independent after the air intake is separated by the air guide mechanism 400; when the size of the fan mechanism 300 is large and the air intake conditions are relatively poor, this state can also achieve a good noise reduction effect.

[0094] It should be noted that the connection portion 521 can be formed by bending a part of the second rectifying net 520. In the actual design process of the range hood, it can be selected whether to set the connection portion 521 with mesh holes according to the benefits of setting the connection portion 521 with mesh holes or not and the actual working environment of the range hood. It should also be noted that the second rectifying net 520 and the air guide mechanism 400 are also integrally formed, that is, the connection portion 521 of the second rectifying net 520 can be fixed as a whole with the part of the air guide mechanism 400 close to the volute 301.

[0095] In addition, it should be noted that the second rectifying net 520 of the present embodiment may also be set to a curved surface, such as a wave shape or a hump shape. When the second rectifying net 520 is a curved surface, the angle A between the first air guide surface 401 and the second rectifying net 520 on the corresponding side and the angle B between the second air guide surface 402 and the second rectifying net 520 on the corresponding side are the angles between the line formed by the overall direction of the second rectifying net 520 along the volute 301 to the inner wall of the chassis 2 and the air guide surface on the corresponding side.

[0096] In this embodiment, the meshes of the first rectifying net 510 , the second rectifying net 520 , and the third rectifying net 530 can all be polygonal holes, preferably hexagonal holes.

[0097] The internal airflow of the smoke collecting chamber 3 of the range hood of this embodiment is straightened by the first rectifying net 510 of the air inlet of the chassis 2 and then enters the inside of the chassis 2, and is guided to the two sides of the chassis 2 along the air guide mechanism 400. Before the airflow enters the fan mechanism 300, it passes through the second rectifying nets 520 on both sides for a second straightening effect. After the airflow passes through the second rectifying net 520, it flows in the space on both sides of the chassis 2, and then passes through the third rectifying nets 530 on the first and second air inlets of the fan mechanism 300 and enters the inside of the fan mechanism 300. At this time, the airflow before entering the inside of the fan mechanism 300 is in a better state after being rectified multiple times at a certain interval, and can enter the inside of the fan smoothly and steadily, reducing aerodynamic noise.

[0098] The noise reduction effect of the range hood of this embodiment is calculated by simulation experiments, and the relationship between the noise reduction amount and different combinations of noise reduction structures is shown in Table 1, where "+" in Table 1 indicates that the corresponding structure is set, and "-" indicates that the corresponding structure is not set.

[0099] Table 1

[0100]

[0101] It can be seen from Table 1 that when only the guide block 110 and the air guide mechanism 400 are set, the noise reduction can reach 1.2dB, when only the first rectifying network 510 and the second rectifying network 520 are set, the noise reduction is 0.8dB, and when the guide block 110, the air guide mechanism 400, the first rectifying network 510 and the second rectifying network 520 are set at the same time, the noise reduction reaches 2dB, which is equal to the sum of the noise reduction when only the guide block 110 and the air guide mechanism 400 are set and when only the first rectifying network 510 and the second rectifying network 520 are set. When only the first rectifying net 510 and the third rectifying net 530 are provided, the noise reduction is 1.2 dB, and when the guide block 110, the air guide mechanism 400, the first rectifying net 510 and the third rectifying net 530 are provided at the same time, the noise reduction reaches 2.4 dB, which is equal to the sum of the noise reduction when only the guide block 110 and the air guide mechanism 400 are provided and when only the first rectifying net 510 and the third rectifying net 530 are provided. Similarly, the noise reduction that can be achieved by other multiple combinations is equal to or substantially equal to the sum of the noise reduction when the multiple combinations are provided separately. It can be seen that this embodiment increases each noise reduction dimension through the reasonable arrangement of the guide block 110, the air guide mechanism 400, the first rectifying net 510, the second rectifying net 520, the third rectifying net 530, and the air outlet cover 600, which can further improve the noise reduction effect and achieve multi-dimensional noise reduction. There is no mutual interference between the overall noise reduction, and the noise reduction of each dimension can still be maintained at a better effect, which solves the problem of mutual interference of multi-dimensional noise reduction, and some dimensions may not have noise reduction effect, which leads to a large gap between the multi-dimensional noise reduction effect and the expected dimensional superposition effect.

[0102] In summary, the range hood of this embodiment adopts multi-dimensional noise reduction, and can perform multi-dimensional noise reduction in the area where the oil smoke airflow enters the smoke collecting chamber 3-enters the chassis 2-enters the fan mechanism 300-is discharged into the air outlet 700, so as to achieve a comprehensive reduction in the operating noise of the whole machine. The first dimension is to use the guide block 110 set in the smoke collecting hood 100, so that the airflow will no longer change direction, and smoothly transition to the chassis 2 along the guide block 110, and then be distributed to both sides of the chassis 2 through the air guide mechanism 400. The second dimension is to use the rectifying effect of the first rectifying net 510 and the second rectifying net 520 to rectify the airflow once before entering the chassis 2 and before entering the fan mechanism 300, so that the airflow flows dispersedly. The third dimension is to use the third rectifying net 530 to rectify and comb the airflow entering the fan mechanism 300, so that the airflow can enter the fan mechanism 300 smoothly and smoothly, reducing aerodynamic noise. The fourth dimension is that the outlet of the air outlet hood 600 is inclined toward the side of the volute tongue 302, so that the connection position between the volute tongue 302 and the air outlet hood 600 and the connection position between the air outlet hood 600 and the air outlet pipe 700 have a smoother transition and reduced flow impact; and the connection between the air outlet hood 600 and the air outlet pipe 700 away from the side of the volute tongue 302 has a straight transition without an impact angle, thereby eliminating the low-speed area and vortex generation at the connection.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fume hood, used to be connected to a housing (2) of a range hood, characterized in that: The top wall of the smoke hood (100) is provided with a reinforcement portion (120) protruding in the direction of the chassis (2), and the inner wall of the top wall is provided with a guide block (110), and the distance between the bottom surface of the guide block (110) away from the top wall and the inner wall of the top wall is not less than the distance that the reinforcement portion (120) protrudes relative to the inner wall of the top wall; The guide block (110) is arranged in a box body, and a plurality of silencer holes are arranged on the bottom surface of the guide block (110) away from the top wall; The circumferential side surface of the guide block (110) is provided with an opening (111); The opening (111) is arranged at one end of the guide block (110) close to the chassis (2); or the opening (111) is arranged on two opposite side surfaces of the guide block (110); The smoke collecting chamber of the smoke collecting hood is provided with a convex structure surrounding the outside of the entrance at a position close to the entrance of the chassis (2); the reinforcement part (120) is the convex structure; and the guide block (110) is provided between the side wall of the smoke collecting hood (100) and the outer edge of the reinforcement part (120); The airflow formed by the smoke flows along the surface of the guide block (110) facing the smoke inlet to the inlet of the chassis (2).

2. The smoke hood according to claim 1, characterized in that: The guide block (110) is arranged on a side of the reinforcement portion (120) away from the chassis.

3. The smoke collecting hood according to claim 1, characterized in that: A sound absorbing structure is arranged inside the guide block (110).

4. A range hood, characterized in that: It comprises a machine case (2) and a smoke collecting hood (100) according to any one of claims 1 to 3, wherein the machine case (2) is fixedly connected to the smoke collecting hood (100).

5. The range hood according to claim 4, characterized in that: The range hood further comprises a fan mechanism (300), wherein the fan mechanism (300) is installed in the housing (2), and the fan mechanism (300) comprises a volute (301), wherein a first air inlet and a second air inlet are respectively formed on the left and right sides of the volute (301); An air guide mechanism (400) is provided below the volute (301), and the air guide mechanism (400) is formed with a first air guide surface (401) and a second air guide surface (402), wherein the first air guide surface (401) is used to guide the oil fume airflow to the first air inlet, and the second air guide surface (402) is used to guide the oil fume airflow to the second air inlet.

6. The range hood according to claim 5, characterized in that: The air guide mechanism (400) is fixed on the bottom of the volute (301), and the distance between an end of the air guide mechanism (400) away from the volute (301) and the bottom of the volute (301) is not less than 50 millimeters, and not greater than the length between the air inlet of the chassis (2) and the bottom of the volute (301).

7. The range hood according to claim 5, characterized in that: A first rectifying net (510) is arranged on the air inlet of the chassis (2), and the air guide mechanism (400) is arranged above the first rectifying net (510); and / or between the volute (301) and the chassis (2), second rectifying nets (520) are respectively arranged on the sides corresponding to the first air inlet and the second air inlet; And / or a third rectifying net (530) is provided on both the first air inlet and the second air inlet.

8. The range hood according to claim 5, characterized in that: A second rectifying net (520) is provided between the volute (301) and the chassis (2), corresponding to the first air inlet and the second air inlet. The angle A between the first air guide surface (401) and the second rectifying net (520) on the corresponding side thereof is not greater than 180 degrees, so that the second rectifying net (520) and the first air inlet of the volute (301) are arranged at a distance, and the angle A is not less than a first reference angle; a line L1 connecting the bottom of the edge of the volute (301) on the side corresponding to the first air inlet and the lower edge of the side wall of the case (2) on the corresponding side and the air guide mechanism (400) away from the volute (301) An angle A1 is formed between a plane L2 where a first air guide surface (401) is located when one end of the volute (301) is in the highest state that can be set; an angle A2 is formed between a line L3 connecting the lower edge of the first air inlet and the lower edge of the side wall on the corresponding side of the case (2) and a line L4 connecting the bottom of the edge of the volute (301) on the side corresponding to the first air inlet and the center of the air inlet of the case (2); the first reference angle is the smaller of the angle A1 and the angle A2; The angle B between the second air guide surface (402) and the second rectifying net (520) on the corresponding side thereof is not greater than 180 degrees, so that the second rectifying net (520) and the second air inlet of the volute (301) are arranged at a distance, and the angle B is not less than a second reference angle; a line L5 connecting the bottom of the edge of the volute (301) on the side corresponding to the second air inlet and the lower edge of the side wall of the case (2) on the corresponding side and the air guide mechanism (400) is spaced away from the volute (301). An angle B1 is formed between a plane L6 where the second air guide surface (402) is located when one end of the volute (301) is in the highest state that can be set; an angle B2 is formed between a line L7 connecting the lower edge of the second air inlet and the lower edge of the side wall on the corresponding side of the chassis (2) and a line L8 connecting the bottom of the edge of the volute (301) on the side corresponding to the second air inlet and the center of the air inlet of the chassis (2); and the second reference angle is the smaller of the angle B1 and the angle B2.

9. The range hood according to claim 8, characterized in that: The second rectifying net (520) is provided with a connecting portion (521), the second rectifying net (520) is connected to the volute (301) via the connecting portion (521), and mesh holes are provided on the connecting portion (521) or both sides of the connecting portion (521) are isolated from each other; and / or the second rectifying network (520) is connected to the inner walls of both the front side and the rear side of the chassis (2); and / or the angle A is between 70° and 180°, and the angle B is between 60° and 180°; And / or the second rectifying network (520) is in a curved shape.

10. The range hood according to claim 5, characterized in that: A first rectifying net (510) is arranged on the air inlet of the chassis (2), and the first rectifying net (510) is arranged parallel to the air inlet of the chassis (2); A second rectifying net (520) is provided between the volute (301) and the chassis (2), corresponding to the first air inlet and the second air inlet, respectively; the first rectifying net (510) and the second rectifying net (520) are integrally formed, and / or the second rectifying net (520) and the air guide mechanism (400) are integrally formed.

11. The range hood according to claim 7, characterized in that: The meshes of the first rectifying net (510), the second rectifying net (520) and / or the third rectifying net (530) are hexagonal.

12. The range hood according to claim 5, characterized in that: An air outlet hood (600) is connected to the chassis (2), the air outlet hood (600) is in communication with the air outlet of the volute (301), and the air outlet hood (600) is inclined relative to the top of the chassis (2) and faces the volute tongue (302) of the volute (301).

13. The range hood according to claim 12, characterized in that: The angle between the side wall (601) of the air outlet cover (600) away from the volute tongue (302) and the extension line of the side surface (3011) of the air outlet of the volute (301) away from the volute tongue (302) is 0 degrees to 10 degrees; The angle between the side wall (602) of the air outlet cover (600) close to the volute tongue (302) and the inner side surface (3012) of the volute tongue (302) is greater than the sum of the volute tongue inclination angle and 90 degrees, and is not greater than 180 degrees.

14. The range hood according to claim 13, characterized in that: A connecting valve (610) is provided on the air outlet of the air outlet cover (600), and the connecting valve (610) is arranged to be inclined from a side away from the volute tongue (302) to a side close to the volute tongue (302) and gradually approach the chassis (2), and the inclination angle of the connecting valve (610) relative to the plane where the top of the chassis (2) is located is 5 degrees to 15 degrees.

Images