An air outlet assembly, a range hood applying the air outlet assembly and a control method of the range hood

Abstract

The application relates to an air outlet assembly, a range hood applying the air outlet assembly and a control method of the range hood, the air outlet assembly comprising: an air outlet cover with an air outlet channel inside; a valve plate for opening or closing the air outlet channel; a smoke pipe arranged above the air outlet cover and communicated with the air outlet cover; characterized in that: the air outlet cover comprises an inner ring and an outer ring which are arranged at the outer circumferential wall of the air outlet end of the air outlet channel and enclose a chamber with an open top, the bottom of the chamber is provided with a connecting part connecting the inner ring and the outer ring and an auxiliary air inlet, and a baffle capable of closing or opening the auxiliary air inlet is arranged in the chamber; the smoke pipe comprises an inner smoke pipe and an outer smoke pipe which are arranged in layers, the inner smoke pipe is arranged above the inner ring and is butted against the upper end surface of the inner ring to form an inner layer channel communicated with the air outlet channel, and the outer smoke pipe is arranged above the outer ring and is butted against the upper end surface of the outer ring to form an outer layer channel communicated with the chamber between the inner wall of the outer smoke pipe and the outer wall of the inner smoke pipe.

Description

Technical Field

[0001] This invention relates to the field of range hood technology, and in particular to an air outlet component, a range hood using the air outlet component, and a control method thereof. Background Technology

[0002] A range hood is a kitchen appliance designed to purify the kitchen environment. It works on the principle of fluid dynamics, using a centrifugal fan installed inside to draw in and exhaust cooking fumes. The centrifugal fan consists of a casing, an impeller housed within the casing, and a motor that drives the impeller. As the impeller rotates, a negative pressure is generated at the center of the fan, drawing in the cooking fumes from below. After being accelerated by the fan, the fumes are collected by the casing and guided outwards.

[0003] Currently, most range hoods on the market use exhaust pipes to input the fumes from the fan system into a common flue. A check valve is also installed at the outlet of the exhaust pipe. Because the check valve relies on the range hood's airflow to open and its own weight or a spring to close, its weight or spring force cannot be too great to ensure the range hood's airflow can open it. Therefore, the check valve's closing force is relatively small, resulting in a less than tight seal. Furthermore, long-term use and the accumulation of grease can also cause the check valve to not close properly.

[0004] To address the aforementioned technical problems, Chinese invention patent application number CN201911207210.7 (publication number CN110779065A) discloses a range hood and its usage method for preventing backflow of cooking fumes. The device includes: a main exhaust pipe; a range hood main unit located above or to one side of the source of cooking fumes; a fan connected to the exhaust end of the range hood main unit; an exhaust pipe with both ends connected to the main exhaust pipe and the range hood main unit respectively; a check valve located at one end of the exhaust pipe connected to the main exhaust pipe; a flue shut-off valve located at one end of the exhaust pipe near the range hood main unit; a heating sleeve fitted around the outer periphery of the exhaust pipe located between the flue shut-off valve and the check valve; and a heating source connected to the heating sleeve for providing heat.

[0005] Although this range hood can use a heating source and heating sleeve to heat the exhaust pipe section located between the check valve and the pipe shut-off valve, preventing excessive oil fumes from adhering to and accumulating on the check valve to improve its ability to close properly, the check valve requires certain installation conditions. Therefore, some users do not have the conditions to install it, especially households without a shared exhaust duct, which often choose to directly exhaust oil fumes outdoors. These users place the exhaust pipe outside the window or wall. Due to frequent large airflow fluctuations, rain, snow, or wild animals in the external environment, it is very easy for outside wind / rain / snow to flow back into the indoor range hood, causing a reduction in the performance of the fan system and greatly affecting the user's cooking experience.

[0006] Therefore, further improvements to existing technologies are needed. Summary of the Invention

[0007] The first technical problem to be solved by the present invention is to provide an air outlet component that can prevent backflow and ensure the performance of the fan, in contrast to the above-mentioned prior art.

[0008] The second technical problem to be solved by the present invention is to provide a range hood that uses the air outlet component.

[0009] The third technical problem to be solved by the present invention is to provide a control method for a range hood as described above.

[0010] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: an air outlet assembly, comprising:

[0011] An air vent hood has an internal air outlet channel, with a main air inlet and an air outlet at each end of the air outlet channel.

[0012] The flue is located above the exhaust hood and is connected to the exhaust hood.

[0013] A valve plate is rotatably disposed in the air outlet channel to open or close the air outlet channel;

[0014] The feature is that: the air outlet hood includes an inner ring and an outer ring spaced apart on the outer peripheral wall of the air outlet end of the air outlet channel, and the two together form a cavity with an open top. The bottom of the cavity has a connecting part connecting the inner ring and the outer ring and an auxiliary air inlet. The cavity is also provided with a baffle that can close or open the auxiliary air inlet.

[0015] The flue includes an inner flue and an outer flue, which are arranged in an inner and outer manner. The inner flue is located above the inner ring and faces the upper end of the inner ring, so that the inner wall of the inner flue and the inner wall of the inner ring together form an inner channel that communicates with the air outlet channel. The outer flue is located above the outer ring and faces the upper end of the outer ring, so that the inner wall of the outer flue and the outer wall of the inner flue form an outer channel that communicates with the chamber.

[0016] To further prevent backflow in the flue, the air outlet assembly also includes an elastic membrane made of elastic material, which is configured to be selectively installed inside the inner flue or between the inner flue and the outer flue.

[0017] With the elastic membrane installed inside the inner smoke pipe, the elastic membrane can seal the inner smoke pipe and can deform under the action of airflow to at least partially seal the area between the inner smoke pipe and the outer smoke pipe.

[0018] With the elastic membrane installed between the inner and outer smoke pipes, the elastic membrane can seal the area between the inner and outer smoke pipes and can deform under the action of airflow to at least partially seal the inner smoke pipe.

[0019] To facilitate the installation of the flue, the height of the inner ring is higher than the height of the outer ring.

[0020] To facilitate the installation of the elastic membrane, when the flue is installed on the air outlet hood, the top of the inner flue is lower than the top of the outer flue.

[0021] In order to achieve the deformation of the elastic membrane to correspondingly close other areas of the smoke pipe outlet, the elastic membrane is provided at the top of the inner smoke pipe, or the elastic membrane is connected to the top of the inner smoke pipe and the top of the outer smoke pipe respectively.

[0022] To connect the inner and outer smoke pipes, the outer channel is also provided with fixing rods that are respectively connected to the outer wall of the inner smoke pipe and the inner wall of the outer smoke pipe.

[0023] To enable the valve to rotate automatically, a first motor that can drive the valve plate to rotate is also installed on the air outlet cover. The first motor is connected to the valve plate drive.

[0024] To enable the automatic movement of the baffle, a second motor is also provided in the chamber to drive the movement of the baffle. The second motor is connected to the baffle drive to close or open the auxiliary air inlet.

[0025] To improve ventilation, at least one auxiliary air inlet is provided, and they are spaced circumferentially at the bottom of the chamber.

[0026] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a range hood, characterized in that: it includes the above-mentioned air outlet component.

[0027] In this solution, the range hood includes a housing and a fan system disposed within the housing. The fan system includes a volute, an impeller disposed within the volute, and a drive motor for driving the impeller to rotate. The air outlet of the volute is connected to the main air inlet of the air outlet channel.

[0028] The technical solution adopted by the present invention to solve the third technical problem mentioned above is: a control method for a range hood as described above, characterized by comprising the following steps:

[0029] Step 1: After the range hood has finished working, turn it off.

[0030] Step 2: Obtain the current status of the air outlet component. This status includes four states:

[0031] First condition: Chip blockage;

[0032] Second state: An elastic membrane is installed between the inner smoke pipe and the outer smoke pipe;

[0033] Third state: An elastic membrane is installed inside the inner smoke pipe;

[0034] Fourth state: Inelastic membrane;

[0035] The first and fourth states mentioned above are abnormal states at the flue outlet, while the second and third states mentioned above are normal states at the flue outlet.

[0036] Step 3: Determine if the flue outlet is in normal condition. If yes, proceed to Step 4; otherwise, remind the user to perform maintenance and end the process.

[0037] Step 4: Input a preset current A1 into the drive motor;

[0038] Step 5: Control the blocking end motor to turn on; if the current air outlet component is in the second state, then the blocking end motor is the second motor; if the current air outlet component is in the third state, then the blocking end motor is the first motor.

[0039] Step 6: Determine whether the speed of the blocked end motor in Step 5 is greater than the corresponding speed threshold and the speed fluctuation is less than the preset fluctuation threshold p. If yes, proceed to Step 7; otherwise, proceed to Step 4.

[0040] Step 7: Turn off the motor on the blocked end and turn off the drive motor to finish.

[0041] In this solution, the specific steps for obtaining the current air outlet component status in step 2 are as follows:

[0042] Step 2-1: Apply a preset current to the fan system;

[0043] Step 2-2: Start the first motor to open the air outlet duct, and record the speed n1 of the drive motor at this time;

[0044] Steps 2-3: Turn off the first motor to close the air outlet and start the second motor to open the auxiliary air inlet. Record the speed n2 of the drive motor at this time.

[0045] Steps 2-4: Compare n1 with na and n2 with nb respectively, and obtain the current air outlet component status based on the two comparison results; where na is the drive motor speed threshold when only the air outlet channel is open, and nb is the drive motor speed threshold when only the auxiliary air inlet is open.

[0046] Furthermore, the specific control logic in steps 2-4 is as follows:

[0047] When n1 > na and n2 > nb, the system is classified as the first state, and the user is reminded to perform maintenance.

[0048] When n1 < na and n2 > nb, it is determined to be the second state;

[0049] When n1 > na and n2 < nb, it is determined to be the third state;

[0050] When n1 < na and n2 < nb, it is determined to be the fourth state, reminding the user to install the elastic membrane.

[0051] To enable the range hood to turn on, if step 1 involves turning on the range hood when it is not in operation, the control method described above includes the following steps:

[0052] Step a: Obtain the current status of the air outlet component in the same way as in step 2;

[0053] Step b: Simultaneously turn on the first motor and the second motor;

[0054] Step c: After the first and second motors have been running for a certain period of time, turn off the motor at the blocked end;

[0055] Step d: Start the drive motor.

[0056] Compared with existing technologies, the advantages of this invention are as follows: First, the inner wall of the inner flue and the inner wall of the inner ring together form an inner channel that communicates with the air outlet channel. Furthermore, a valve plate is rotatably provided within the air outlet channel to open or close the air outlet channel, thus allowing the inner channel to be closed or opened. Second, an outer channel is formed between the inner wall of the outer flue and the outer wall of the inner flue, communicating with the chamber. A baffle plate is also provided within the chamber to close or open the auxiliary air inlet, thus allowing the outer channel to be closed or opened. Therefore, this air outlet assembly can prevent backflow through the valve plate and baffle plate. Of course, the inner and outer channels ensure the normal operation of the entire unit, improving the user experience. Moreover, it can be installed according to the actual conditions of the user's home, greatly expanding the application scenarios of the fan. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the structure of the range hood in an embodiment of the present invention;

[0058] Figure 2 for Figure 1 Exploded view of the center air outlet assembly;

[0059] Figure 3 This is a cross-sectional view of the air outlet assembly in an embodiment of the present invention (the air outlet channel is closed, the auxiliary air inlet is open, and the elastic membrane is installed between the inner smoke pipe and the outer smoke pipe).

[0060] Figure 4This is a cross-sectional view of the air outlet assembly in an embodiment of the present invention (the air outlet channel is open, the auxiliary air inlet is closed, and the elastic membrane is installed between the inner smoke pipe and the outer smoke pipe).

[0061] Figure 5 This is a cross-sectional view of the air outlet assembly in an embodiment of the present invention (the air outlet channel is open, the auxiliary air inlet is open, and the elastic membrane is installed between the inner smoke pipe and the outer smoke pipe).

[0062] Figure 6 This is a cross-sectional view of the air outlet assembly in an embodiment of the present invention (the air outlet channel is closed, the auxiliary air inlet is closed, and the elastic membrane is installed between the inner smoke pipe and the outer smoke pipe);

[0063] Figure 7 This is a cross-sectional view of the air outlet assembly in an embodiment of the present invention (the air outlet channel is closed, the auxiliary air inlet is closed, and the elastic membrane is installed inside the inner flue).

[0064] Figure 8 for Figure 1 Partial sectional view. Detailed Implementation

[0065] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0066] like Figures 1-8 As shown, in this embodiment, the range hood includes a housing 9, a fan system disposed within the housing 9, and an air outlet assembly disposed outside the housing 9. The fan system includes a volute 9a, an impeller 9b disposed within the volute 9a, and a drive motor 9c for driving the impeller 9b to rotate. The air outlet assembly includes an air outlet hood 1 and a flue 3. The air outlet hood 1 has an air outlet channel 10 inside, with a main air inlet 10a and an air outlet 10b at its two ends. A valve 2 is rotatably disposed within the air outlet channel 10 to open or close the air outlet channel 10. The air outlet of the volute 9a is connected to the main air inlet 10a of the air outlet channel 10. The flue 3 is disposed above the air outlet hood 1 and is connected to the air outlet hood 1.

[0067] In this embodiment, the air outlet cover 1 includes an inner ring 11 and an outer ring 12 spaced apart on the outer peripheral wall of the air outlet 10b end of the air outlet channel 10, and the two together form a top-opening chamber 100. The bottom of the chamber 100 has a connecting part connecting the inner ring 11 and the outer ring 12 and an auxiliary air inlet 101 is provided. The chamber 100 is also provided with a baffle 4 that can close or open the auxiliary air inlet 101.

[0068] A first motor 7, capable of driving the valve plate 2 to rotate, is also installed on the air outlet shroud 1. The first motor 7 is driven and connected to the valve plate 2. A second motor 8, for driving the baffle 4 to move, is also provided inside the chamber 100. The second motor 8 is driven and connected to the baffle 4 to close or open the auxiliary air inlet 101. There is at least one auxiliary air inlet 101, circumferentially spaced at the bottom of the chamber 100. In this embodiment, there are four auxiliary air inlets 101, such as... Figure 2 As shown, there are also 4 baffles 4. Each baffle 4 corresponds to closing or opening one of the auxiliary air inlets 101. The second motor 8 can be multiple or a single motor, which can drive all the baffles 4 to move simultaneously.

[0069] In this embodiment, the flue 3 includes an inner flue 31 and an outer flue 32, which are enclosed by an inner and outer casing. The inner flue 31 is located above the inner ring 11 and faces the upper end of the inner ring 11, so that the inner wall of the inner flue 31 and the inner wall of the inner ring 11 together form an inner channel 3a that communicates with the air outlet channel 10. The outer flue 32 is located above the outer ring 12 and faces the upper end of the outer ring 12, so that the inner wall of the outer flue 32 and the outer wall of the inner flue 31 form an outer channel 3b that communicates with the chamber 100. A fixing rod 6 is also provided in the outer channel 3b, which is connected to the outer wall of the inner flue 31 and the inner wall of the outer flue 32 respectively. The fixing rod 6 is a flexible hose, and its main purpose is to fix the inner flue 31 and the outer flue 32.

[0070] Additionally, the air outlet assembly includes an elastic membrane 5 made of an elastic material, which is configured to be selectively installed inside the inner smoke pipe 31 or between the inner smoke pipe 31 and the outer smoke pipe 32; for example Figure 7 As shown, with the elastic membrane 5 installed inside the inner smoke pipe 31, the elastic membrane 5 can seal the inner smoke pipe 31 and can deform under the action of airflow to at least partially seal the area between the inner smoke pipe 31 and the outer smoke pipe 32; as Figures 3-6 As shown, when the elastic membrane 5 is installed between the inner smoke pipe 31 and the outer smoke pipe 32, the elastic membrane 5 can seal the area between the inner smoke pipe 31 and the outer smoke pipe 32, and can deform under the action of airflow to at least partially seal the inner smoke pipe 31.

[0071] To facilitate the installation of the flue pipe 3, the inner ring 11 is higher than the outer ring 12; additionally, to facilitate the installation of the elastic diaphragm 5, when the flue pipe 3 is installed on the exhaust hood 1, the top of the inner flue pipe 31 is lower than the top of the outer flue pipe 32. Figure 7 As shown, the elastic membrane 5 is disposed at the top of the inner smoke pipe 31, or as... Figures 3-6 As shown, the elastic membrane 5 is connected to the top of the inner smoke pipe 31 and the top of the outer smoke pipe 32, respectively.

[0072] The control method for the range hood in this embodiment includes the following steps:

[0073] Step 1: After the range hood has finished working, turn it off.

[0074] Step 2: Obtain the current status of the air outlet component. This status includes four states:

[0075] First condition: Chip blockage;

[0076] Second state: An elastic membrane is installed between the inner smoke pipe and the outer smoke pipe;

[0077] Third state: An elastic membrane is installed inside the inner smoke pipe;

[0078] Fourth state: Inelastic membrane;

[0079] The first and fourth states mentioned above are abnormal states at the flue outlet, while the second and third states mentioned above are normal states at the flue outlet.

[0080] In this embodiment, the specific steps for obtaining the current status of the air outlet component are as follows:

[0081] Step 2-1: Apply a preset current to the fan system;

[0082] Step 2-2: Start the first motor to open the air outlet duct, and record the speed n1 of the drive motor at this time;

[0083] Steps 2-3: Turn off the first motor to close the air outlet and start the second motor to open the auxiliary air inlet. Record the speed n2 of the drive motor at this time.

[0084] Steps 2-4: Compare n1 with na and n2 with nb respectively, and obtain the current status of the air outlet component based on the two comparison results; where na is the drive motor speed threshold when only the air outlet channel is open, and nb is the drive motor speed threshold when only the auxiliary air inlet is open.

[0085] The specific control logic for the above comparison is as follows:

[0086] When n1 > na and n2 > nb, the system is classified as the first state, and the user is reminded to perform maintenance.

[0087] When n1 < na and n2 > nb, it is determined to be the second state;

[0088] When n1 > na and n2 < nb, it is determined to be the third state;

[0089] When n1 < na and n2 < nb, it is determined to be the fourth state, reminding the user to install the elastic membrane;

[0090] This control method can issue alerts based on the status of the air outlet components, enabling users to promptly identify outlet problems and significantly improving ease of use.

[0091] Step 3: Determine if the flue outlet is in normal condition. If yes, proceed to Step 4; otherwise, remind the user to perform maintenance and end the process.

[0092] Step 4: Input a preset current A1 into the drive motor;

[0093] Step 5: Control the blocking end motor to turn on; if the current air outlet component is in the second state, then the blocking end motor is the second motor; if the current air outlet component is in the third state, then the blocking end motor is the first motor.

[0094] Step 6: Determine whether the speed of the blocked end motor in Step 5 is greater than the corresponding speed threshold and the speed fluctuation is less than the preset fluctuation threshold p. If yes, proceed to Step 7; otherwise, proceed to Step 4.

[0095] Step 7: Turn off the motor on the blocked end and turn off the drive motor to finish.

[0096] If step 1 involves turning on the range hood when it is not in operation, then the above control method includes the following steps:

[0097] Step a: Obtain the current status of the air outlet component in the same way as in step 2;

[0098] Step b: Simultaneously turn on the first motor and the second motor;

[0099] Step c: After the first and second motors have been running for a certain period of time, turn off the motor at the blocked end;

[0100] Step d: Start the drive motor.

[0101] During the operation of the range hood, smoke is exhausted through the inner and outer channels, greatly improving the smoke extraction effect. After the first and second motors have been running for a certain period of time, the blocking end motor is turned off, causing the elastic membrane to block the corresponding channel, thus preventing backflow.

[0102] The exhaust duct is opened or closed by rotating the valve plate, and the auxiliary air inlet at the bottom of the chamber is closed or opened by moving the baffle. Therefore, in this embodiment, closing the exhaust duct prevents backflow into the inner duct, and closing the auxiliary air inlet prevents backflow into the outer duct, thus achieving backflow prevention even without a check valve, ensuring normal operation of the range hood. Furthermore, with both the exhaust duct and the auxiliary air inlet open, smoke can be exhausted through both the inner and outer ducts, greatly expanding the fan's application range. This structure is simple and its function is stable.

Claims

1. A control method for a range hood, the range hood comprising an air outlet assembly, a housing (9), and a fan system disposed within the housing (9), the air outlet assembly comprising: An air hood (1) has an air outlet channel (10) inside, and the two ends of the air outlet channel (10) are a main air inlet (10a) and an air outlet (10b), respectively. The flue (3) is located above the air outlet hood (1) and is connected to the air outlet hood (1); A valve plate (2) is rotatably disposed in the air outlet channel (10) to open or close the air outlet channel (10); The feature is that the air outlet hood (1) includes an inner ring (11) and an outer ring (12) spaced apart on the outer peripheral wall of the air outlet (10b) end of the air outlet channel (10), and the two together form a top-open chamber (100). The bottom of the chamber (100) has a connecting part connecting the inner ring (11) and the outer ring (12) and an auxiliary air inlet (101) is provided. The chamber (100) is also provided with a baffle (4) that can close or open the auxiliary air inlet (101). The flue (3) includes an inner flue (31) and an outer flue (32) with inner and outer casings. The inner flue (31) is located above the inner ring (11) and faces the upper end of the inner ring (11), so that the inner wall of the inner flue (31) and the inner wall of the inner ring (11) together form an inner channel (3a) that communicates with the air outlet channel (10). The outer flue (32) is located above the outer ring (12) and faces the upper end of the outer ring (12), so that the inner wall of the outer flue (32) and the outer wall of the inner flue (31) form an outer channel (3b) that communicates with the chamber (100). The air outlet assembly also includes an elastic membrane (5) made of elastic material, which is configured to be selectively installed inside the inner smoke pipe (31) or between the inner smoke pipe (31) and the outer smoke pipe (32); With the elastic membrane (5) installed inside the inner smoke pipe (31), the elastic membrane (5) can seal the inner smoke pipe (31) and can deform under the action of airflow to at least partially seal the area between the inner smoke pipe (31) and the outer smoke pipe (32); With the elastic membrane (5) installed between the inner smoke pipe (31) and the outer smoke pipe (32), the elastic membrane (5) can close the area between the inner smoke pipe (31) and the outer smoke pipe (32), and can deform under the action of airflow to at least partially close the inner smoke pipe (31); The air outlet cover (1) is also equipped with a first motor (7) that can drive the valve plate (2) to rotate. The first motor (7) is connected to the valve plate (2) in a driving connection. The chamber (100) is also provided with a second motor (8) for driving the baffle (4) to move. The second motor (8) is connected to the baffle (4) to close or open the auxiliary air inlet (101). The control method for a range hood includes the following steps: Step 1: After the range hood has finished working, turn it off. Step 2: Obtain the current status of the air outlet component. This status includes four states: First condition: Chip blockage; Second state: An elastic membrane is installed between the inner smoke pipe and the outer smoke pipe; Third state: An elastic membrane is installed inside the inner smoke pipe; Fourth state: Inelastic membrane; The first and fourth states mentioned above are abnormal states at the flue outlet, while the second and third states mentioned above are normal states at the flue outlet. The specific steps for obtaining the current status of the air outlet component in step 2 are as follows: Step 2-1: Apply a preset current to the fan system; Step 2-2: Start the first motor to open the air outlet duct, and record the speed n1 of the drive motor at this time; Steps 2-3: Turn off the first motor to close the air outlet and start the second motor to open the auxiliary air inlet. Record the speed n2 of the drive motor at this time. Steps 2-4: Compare n1 with na and n2 with nb respectively, and obtain the current status of the air outlet component based on the two comparison results; where na is the drive motor speed threshold when only the air outlet channel is open, and nb is the drive motor speed threshold when only the auxiliary air inlet is open. The specific control logic in steps 2-4 is as follows: When n1 > na and n2 > nb, the system is classified as the first state, and the user is reminded to perform maintenance. When n1 < na and n2 > nb, it is determined to be the second state; When n1 > na and n2 < nb, it is determined to be the third state; When n1 < na and n2 < nb, it is determined to be the fourth state, reminding the user to install the elastic membrane; Step 3: Determine if the flue outlet is in normal condition. If yes, proceed to Step 4; otherwise, remind the user to perform maintenance and end the process. Step 4: Input a preset current A1 into the drive motor; Step 5: Control the blocking end motor to turn on; if the current air outlet component is in the second state, then the blocking end motor is the second motor; if the current air outlet component is in the third state, then the blocking end motor is the first motor. Step 6: Determine whether the speed of the blocked end motor in Step 5 is greater than the corresponding speed threshold and the speed fluctuation is less than the preset fluctuation threshold p. If yes, proceed to Step 7; otherwise, proceed to Step 4. Step 7: Turn off the motor on the blocked end and turn off the drive motor to finish.

2. The control method according to claim 1, characterized in that: The height of the inner ring (11) is higher than the height of the outer ring (12).

3. The control method according to claim 2, characterized in that: With the smoke pipe (3) installed on the air outlet hood (1), the top of the inner smoke pipe (31) is lower than the top of the outer smoke pipe (32).

4. The control method according to claim 3, characterized in that: The elastic membrane (5) is disposed at the top of the inner smoke pipe (31), or the elastic membrane (5) is connected to the top of the inner smoke pipe (31) and the top of the outer smoke pipe (32) respectively.

5. The control method according to claim 4, characterized in that: The outer channel (3b) is also provided with fixing rods (6) that are respectively connected to the outer wall of the inner smoke pipe (31) and the inner wall of the outer smoke pipe (32).

6. The control method according to any one of claims 1 to 5, characterized in that: There is at least one auxiliary air inlet (101), which is circumferentially spaced at the bottom of the chamber (100).

7. The control method according to claim 1, characterized in that: The fan system includes a volute (9a), an impeller (9b) disposed in the volute (9a), and a drive motor (9c) for driving the impeller (9b) to rotate. The air outlet of the volute (9a) is connected to the main air inlet (10a) of the air outlet channel (10).

8. The control method according to claim 1, characterized in that: If step 1 involves turning on the range hood when it is not in operation, then the above control method includes the following steps: Step a: Obtain the current status of the air outlet component in the same way as in step 2; Step b: Simultaneously turn on the first motor and the second motor; Step c: After the first and second motors have been running for a certain period of time, turn off the motor at the blocked end; Step d: Start the drive motor.

Images