Anti-fume device, system and control method of anti-fume device

Abstract

This invention provides an anti-backflow fume device, an anti-backflow fume system, and a control method for the anti-backflow fume device, belonging to the field of fume treatment. An anti-backflow fume device includes: a U-shaped pipe, with its air inlet end connected to the exhaust pipe of a range hood and its exhaust end connected to the main exhaust pipe; a liquid inlet pipe located at the bottom of the U-shaped pipe and connected to the interior of the U-shaped pipe through its liquid inlet end, with a liquid inlet valve on the liquid inlet pipe; a liquid outlet pipe located at the bottom of the U-shaped pipe and connected to the interior of the U-shaped pipe through its liquid outlet end, with a liquid outlet valve on the liquid outlet pipe; and an automatic liquid replacement mechanism electrically connected to both the liquid inlet valve and the liquid outlet valve. The U-shaped pipe can automatically drain and automatically inlet liquid under the control of the automatic liquid replacement mechanism. The U-shaped pipe uses a liquid seal to effectively prevent backflow of fumes into the kitchen.

Description

Technical Field

[0001] This invention relates to the field of oil fume treatment technology, specifically to an anti-backflow oil fume device, an anti-backflow oil fume system, and a control method for the anti-backflow oil fume device. Background Technology

[0002] Kitchen fumes can be harmful to human health. These fumes originate from two sources: the fumes produced during cooking and the backflow of fumes from the main exhaust pipe in the building's stairwell. As residential buildings become taller and have more floors, the pressure in the main exhaust pipe increases, potentially causing fumes to backflow into the range hood, thus continuously impacting human health.

[0003] Existing backflow prevention devices mainly employ mechanical check valves and electric butterfly valves. Mechanical check valves are the most common type used by residents in China. However, after a period of use, the sealing surface of the check valve's closing element may become clogged with oil, preventing a complete seal. In some cases, excessive oil buildup can cause the closing element to jam, leading to a gradual decrease in the backflow prevention effect or even complete failure. Electric butterfly valves, driven by an electric motor, do not have the same problem of jamming as mechanical check valves. However, they still suffer from the issue of oil contamination on the valve disc's sealing surface, leading to incomplete sealing and air leakage.

[0004] This invention provides an anti-backflow fume device, an anti-backflow fume system, and a control method for the anti-backflow fume device, which can effectively prevent backflow of cooking fumes back into the kitchen. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-backflow fume device, an anti-backflow fume system, and a control method for the anti-backflow fume device. The anti-backflow fume device is designed with a U-shaped pipe connecting the range hood and the main exhaust pipe. The U-shaped pipe is sealed with liquid to effectively prevent backflow of fumes into the kitchen.

[0006] To achieve the above objectives, in a first aspect, embodiments of the present invention provide an anti-backflow fume device, comprising:

[0007] The U-shaped pipe has an air inlet end connected to the range hood exhaust pipe and an exhaust end connected to the main exhaust pipe.

[0008] An inlet pipe is located at the bottom of the U-shaped pipe and connects to the inside of the U-shaped pipe through the inlet end of the U-shaped pipe. An inlet valve is provided on the inlet pipe. Injecting sealing liquid into the U-shaped pipe through the inlet pipe can prevent backflow of oil fumes from the exhaust manifold into the exhaust pipe of the range hood.

[0009] A drain pipe is located at the bottom of the U-shaped pipe and communicates with the inside of the U-shaped pipe through the drain end of the U-shaped pipe. A drain valve is provided on the drain pipe.

[0010] An automatic liquid changing mechanism is electrically connected to the inlet valve and the outlet valve, respectively. The U-shaped pipe can automatically drain and automatically fill liquid under the control of the automatic liquid changing mechanism.

[0011] Preferably, the U-shaped pipe is further provided with a first liquid level sensor, a second liquid level sensor and a third liquid level sensor;

[0012] The first liquid level sensor is located on the outer wall of the exhaust end of the U-shaped pipe, and the first liquid level sensor is used to monitor the liquid level inside the U-shaped pipe;

[0013] The second liquid level sensor is located at the bottom of the U-shaped pipe and is used to monitor whether there is liquid inside the U-shaped pipe.

[0014] The third liquid level sensor is located on the outer wall of the air inlet end of the U-shaped pipe, and is used to monitor the maximum liquid level limit inside the U-shaped pipe.

[0015] Preferably, the automatic fluid replacement mechanism is a timer.

[0016] Secondly, embodiments of the present invention provide an anti-backflow fume system, including an automatic liquid replacement module, a control module, and the anti-backflow fume device described above.

[0017] The backflow prevention device is connected to the range hood and the exhaust manifold respectively, and is used to prevent backflow of oil fumes from the exhaust manifold into the range hood through the liquid discharge and liquid inlet of the U-shaped pipe;

[0018] The automatic fluid replacement module is used to set the automatic fluid replacement time point and control the U-shaped pipeline to perform automatic fluid discharge and automatic fluid inlet according to the automatic fluid replacement time point;

[0019] The control module is connected to the automatic liquid replacement module, the drain valve and the inlet valve of the anti-backflow fume device, respectively, and is used to control the operation of the anti-backflow fume device.

[0020] Preferably, the anti-backflow fume system further includes an antifreeze module and an alarm module;

[0021] The antifreeze module includes an antifreeze button, which is connected to the control module and is used to input an antifreeze command to the control module.

[0022] The control module is used to control the liquid inlet and outlet of the U-shaped pipe according to the antifreeze command;

[0023] The control module is also used to output alarm commands to the alarm module;

[0024] The alarm module is connected to the control module and is used to execute alarm actions according to the alarm instructions of the control module.

[0025] Thirdly, embodiments of the present invention provide a control method for an anti-backflow fume device, which applies the anti-backflow fume system described above, and includes the following steps:

[0026] While the range hood is operating, monitor in real time whether there is liquid inside the U-shaped pipe;

[0027] If liquid is detected, control the U-shaped pipe to perform a drainage operation until the liquid in the U-shaped pipe is completely drained;

[0028] When the range hood is not working,

[0029] The U-shaped pipe is used to perform the liquid replenishment operation until the liquid level in the U-shaped pipe reaches the first preset liquid level.

[0030] Preferred options also include:

[0031] When the set automatic liquid replacement time point is reached, the U-shaped pipe is first controlled to perform a liquid drainage operation, and then the U-shaped pipe is controlled to perform a liquid replenishment operation; wherein, the automatic liquid replacement time point is within the time period when the range hood is not in operation.

[0032] Preferably, when the range hood is not working, the liquid level in the U-shaped pipe is monitored in real time. If the liquid level in the U-shaped pipe is lower than the first preset liquid level, a liquid replenishment operation is performed in the U-shaped pipe until the liquid level in the U-shaped pipe reaches the first preset liquid level; wherein the first preset liquid level is set at the exhaust end of the U-shaped pipe.

[0033] Preferably, the liquid level in the U-shaped pipe is monitored in real time. When the liquid level in the U-shaped pipe is greater than or equal to the second preset liquid level, the U-shaped pipe is controlled to perform a liquid drainage operation until the liquid level in the U-shaped pipe is less than the second preset liquid level. The second preset liquid level is set at the air inlet end of the U-shaped pipe, and the horizontal height of the second preset liquid level is higher than the first preset liquid level.

[0034] Preferably, the antifreeze button status is determined when the range hood is not in operation;

[0035] When the antifreeze button is in the closed position, the control U-shaped pipe will first perform the drainage operation and then the replenishment operation.

[0036] This anti-backflow fume device features a U-shaped pipe connecting the range hood and the main exhaust pipe. The U-shaped pipe is sealed with liquid to effectively prevent backflow of fumes into the kitchen. Furthermore, the device is equipped with an automatic liquid replacement mechanism to prevent the liquid inside the U-shaped pipe from deteriorating and polluting the environment when the range hood is not used for a long time.

[0037] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 This is a schematic diagram of the structure of an anti-backflow oil fume device provided in Embodiment 1 of the present invention;

[0040] Figure 2 This is a topology diagram of an anti-backflow fume system provided in Embodiment 1 of the present invention.

[0041] Explanation of reference numerals in the attached figures

[0042] 1-U-shaped pipe, 2-inlet pipe, 3-outlet pipe, 4-inlet valve, 5-outlet valve, 6-first liquid level sensor, 7-second liquid level sensor, 8-third liquid level sensor. Detailed Implementation

[0043] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0044] In embodiments of the present invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. Terms such as "first," "second," and "third" are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0045] The terms "parallel" and "perpendicular" do not mean that the components must be absolutely parallel or perpendicular, but rather that they can be slightly tilted. For example, "parallel" simply means that its direction is more parallel than "perpendicular," not that the structure must be completely parallel, but that it can be slightly tilted.

[0046] The terms "level," "vertical," and "sag" do not imply that components must be absolutely level, vertical, or suspended, but rather that they can be slightly tilted. For example, "level" simply means that its direction is more level than "vertical," not that the structure must be completely level, but can be slightly tilted.

[0047] Furthermore, terms like "roughly" and "basically" are used to indicate that the content does not require absolute precision, but rather allows for a certain degree of deviation. For example, "roughly equal" does not simply mean absolute equality; in actual production and operation, achieving absolute "equality" is difficult, and a certain degree of deviation is generally present. Therefore, besides absolute equality, "roughly equal to" also includes the aforementioned situation where a certain degree of deviation exists. Using this as an example, in other cases, unless otherwise specified, terms like "roughly" and "basically" have similar meanings.

[0048] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] The term "connection" as used in this article refers to an electrical power connection or signal connection between two components; a "connection" can be a direct connection between two elements, a connection through an intermediate medium (such as a wire), or an indirect connection achieved through a third element.

[0050] The term "signal connection" as used in this document refers to a signal connection between two components, such as a control signal and a feedback signal; the term "electrical connection" refers to an electrical power connection between two components; and "connection" can be a direct connection between two parts or an indirect connection achieved through a third part.

[0051] Example 1

[0052] Please refer to Figure 1 In a first aspect, embodiments of the present invention provide an anti-backflow fume device, comprising:

[0053] U-shaped pipe 1, the air inlet end of the U-shaped pipe 1 is connected to the exhaust pipe of the range hood, and the exhaust end of the U-shaped pipe 1 is connected to the main exhaust pipe;

[0054] The liquid inlet pipe 2 is located at the bottom of the U-shaped pipe 1 and is connected to the inside of the U-shaped pipe 1 through the liquid inlet end of the U-shaped pipe 1. The liquid inlet pipe 2 is equipped with a liquid inlet valve 4. Injecting sealing liquid from the liquid inlet pipe 2 into the U-shaped pipe 1 can prevent the backflow of oil fumes in the exhaust main pipe from entering the exhaust pipe of the range hood.

[0055] Drain pipe 3 is located at the bottom of U-shaped pipe 1 and is connected to the inside of U-shaped pipe 1 through the drain end of U-shaped pipe 1. Drain valve 5 is provided on the drain pipe of drain pipe 3.

[0056] An automatic liquid changing mechanism is electrically connected to the inlet valve 4 and the outlet valve 5 respectively. The U-shaped pipe 1 can automatically drain and automatically fill liquid under the control of the automatic liquid changing mechanism.

[0057] Specifically, when the range hood is working, it exhausts kitchen fumes into the main exhaust pipe in the hallway through the U-shaped pipe 1; when the range hood is not working, liquid is injected into the U-shaped pipe 1 to prevent fumes in the main exhaust pipe from flowing back into the range hood through a liquid seal.

[0058] The inlet pipe 2 allows for liquid replenishment to the U-shaped pipe 1 to form a seal. When liquid is injected into the U-shaped pipe 1 to form a seal, the liquid level at the inlet end of the U-shaped pipe 1 will be higher than the liquid level at the exhaust end due to the pressure of the main exhaust pipe, thus creating a liquid level difference.

[0059] The drain pipe 3 is designed to allow the drain pipe 1 to drain, so that the range hood can function properly.

[0060] The automatic fluid replacement mechanism is used for automatic fluid drainage and inlet. Specifically, in this embodiment, the automatic fluid replacement mechanism includes a controller and a timer. The controller is electrically connected to the inlet valve 4, the drain valve 5, and the timer. The controller controls the opening and closing of the inlet valve 4 or the drain valve 5, and the timer is used for timing. The automatic fluid replacement time point is set by the timer. When the automatic fluid replacement time point is reached, the controller controls the drain valve 5 to open, draining the liquid in the U-shaped pipe 1. Then, the controller controls the inlet valve 4 to open, allowing the liquid to enter the U-shaped pipe 1 through the inlet pipe 2 to replenish the U-shaped pipe 1, thereby achieving the function of automatic fluid replacement.

[0061] In this embodiment, one end of the inlet pipe 2 is connected to a household tap water pipe, and one end of the drain valve 5 is connected to a sewer.

[0062] In this embodiment, the U-shaped pipe 1 is also equipped with a first liquid level sensor 6, a second liquid level sensor 7, and a third liquid level sensor 8;

[0063] The first liquid level sensor 6 is disposed on the outer wall of the exhaust end of the U-shaped pipe 1, and the first liquid level sensor 6 is used to monitor the liquid level inside the U-shaped pipe 1;

[0064] The second liquid level sensor 7 is located at the bottom of the U-shaped pipe 1, and is used to monitor whether there is liquid in the U-shaped pipe 1;

[0065] The third liquid level sensor 8 is located on the outer wall of the air inlet end of the U-shaped pipe 1, and the third liquid level sensor 8 is used to monitor the maximum liquid level limit in the U-shaped pipe 1.

[0066] Specifically, the first liquid level sensor 6 is used to monitor the inlet water level in the U-shaped pipe 1. On the one hand, it limits the replenishment of liquid, and on the other hand, the first liquid level sensor 6 is set at a height in the U-shaped pipe 1 to achieve a sealing effect. When the liquid in the U-shaped pipe 1 reaches the height that the first liquid level sensor 6 can detect, the purpose of forming a water seal is met, and water addition can be stopped. On the other hand, the first liquid level sensor 6 can also resist the pressure of backflow of fumes. Specifically, when liquid is injected into the U-shaped pipe 1 to form a seal, the pressure on both sides of the U-shaped pipe 1 is balanced. However, once the number of households using range hoods in the residential building increases, the backflow pressure of fumes on the main exhaust pipe side increases, and the liquid level at the exhaust end of the U-shaped pipe 1 will decrease under the influence of pressure, affecting the sealing effect. Therefore, when the liquid level is lower than the monitoring value of the first liquid level sensor 6, liquid is added to the U-shaped pipe 1. At this time, due to the influence of the pressure of the main exhaust pipe, the newly added liquid will flow to the air inlet end of the U-shaped pipe 1, and the liquid level difference between the air inlet end and the exhaust end will gradually increase, that is, the water level pressure difference will gradually increase until a new balance is reached, resisting the pressure of backflow of fumes from the main exhaust pipe.

[0067] The second liquid level sensor 7 is located at the bottom of the U-shaped pipe 1 to monitor whether there is still liquid inside the U-shaped pipe 1. Only when the liquid in the U-shaped pipe 1 is completely drained can the range hood achieve 100% unobstructed operation and be used normally.

[0068] The third liquid level sensor 8 is installed on the outer wall of the air inlet end of the U-shaped pipe 1 to prevent excessive liquid levels from entering the range hood and damaging it. When the third liquid level sensor 8 detects a liquid level, it indicates that the liquid in the U-shaped pipe 1 has reached its maximum limit and needs to be drained to lower the liquid level. Furthermore, when the liquid in the U-shaped pipe 1 reaches its maximum limit, an alarm is triggered to remind the user to drain the liquid in the U-shaped pipe 1 and check the system.

[0069] In this embodiment, the automatic fluid replacement mechanism is a timer.

[0070] In this embodiment, the bottom of the U-shaped pipe 1 is provided with a connecting pipe 9. The U-shaped pipe 1 is connected to the inlet pipe 2 and the outlet pipe 3 through the connecting pipe 9. The inlet valve 4 is disposed between the connecting pipe 9 and the inlet pipe 2, and the outlet valve 5 is disposed between the connecting pipe 9 and the outlet pipe 3. Both the inlet valve 4 and the outlet valve 5 are electric ball valves. Specifically, the connecting pipe 9 is used to connect the inlet pipe 2 and the outlet pipe 3. A connecting pipe 9 connects the U-shaped pipe 1, and then connects the inlet pipe 2 and the outlet pipe 3.

[0071] When a connecting pipe 9 is provided, the second liquid level sensor 7 is located at the end of the connecting pipe 9 near the U-shaped pipe 1. Since the U-shaped pipe 1 is connected to the connecting pipe 9, the second liquid level sensor 7 can be installed at the end of the connecting pipe 9 to more accurately detect whether there is still liquid in the U-shaped pipe 1.

[0072] In particular, the air inlet end of the U-shaped pipe 1 should be high enough to prevent liquid from entering the range hood and to resist the backflow pressure from the exhaust manifold.

[0073] Please refer to Figure 2 Secondly, embodiments of the present invention provide an anti-backflow fume system, including an automatic liquid replacement module, a control module, and the anti-backflow fume device described above.

[0074] The backflow prevention device is connected to the range hood and the exhaust main pipe respectively, and is used to prevent backflow of oil fumes from the exhaust main pipe into the range hood through the liquid discharge and liquid inlet of the U-shaped pipe 1.

[0075] The automatic fluid replacement module is used to set the automatic fluid replacement time point and control the U-shaped pipe 1 to perform automatic fluid discharge and automatic fluid inlet according to the automatic fluid replacement time point;

[0076] The control module is connected to the automatic liquid replacement module, the drain valve 5 of the anti-backflow fume device, and the inlet valve 4, respectively, and is used to control the operation of the anti-backflow fume device.

[0077] Specifically, the control module is electrically connected to the first liquid level sensor 6, the second liquid level sensor 7, the third liquid level sensor 8, the drain valve 5, and the inlet valve 4, respectively.

[0078] When the range hood is working, i.e., when liquid is not required to be injected into U-shaped pipe 1:

[0079] The control module receives the monitoring signal from the second liquid level sensor 7. If the second liquid level sensor 7 detects the presence of liquid level, it sends a drain command to the control module. The control module controls the drain valve 5 to open and drain the liquid in the U-shaped pipe 1. The control module also controls the inlet valve 4 to close to prevent liquid from flowing into the U-shaped pipe 1 from the inlet valve 4.

[0080] When the range hood is not working, liquid needs to be injected into U-shaped pipe 1 to form a water seal:

[0081] The control module controls the opening of the inlet valve 4 to inject sealing liquid into the U-shaped pipe 1. The first liquid level sensor 6 monitors the liquid level at all times. When the liquid level is detected, it sends a signal to the control module, and the control module closes the inlet valve 4, thus completing the liquid injection process.

[0082] The third liquid level sensor 8 monitors the liquid level at all times. When the third liquid level sensor 8 detects the liquid level, it sends a signal to the control module. The control module then opens the drain valve 5 to discharge the liquid from the U-shaped pipe 1, preventing the liquid in the U-shaped pipe 1 from entering the range hood and causing damage to it.

[0083] The control module is also connected to the automatic liquid changing mechanism to receive liquid changing instructions from the automatic liquid changing mechanism. When the automatic liquid changing time point set by the automatic liquid changing mechanism is reached, the automatic liquid changing mechanism sends a liquid changing instruction to the control module. The control module controls the drain valve 5 to open, and the liquid is discharged from the U-shaped pipe 1. After the second liquid level sensor 7 detects that the liquid in the U-shaped pipe 1 has been drained, the control module controls the drain valve 5 to close and the inlet valve 4 to open, and the liquid enters the U-shaped pipe 1 from the inlet pipe 2.

[0084] In this embodiment, the anti-backflow fume system also includes an antifreeze module and an alarm module;

[0085] The antifreeze module includes an antifreeze button, which is connected to the control module. The antifreeze button is used to input an antifreeze command to the control module, and the control module executes the antifreeze command to control the liquid inlet and outlet of the U-shaped pipe 1.

[0086] Specifically, the antifreeze function can be used as needed. When the user uses the antifreeze function, they press the antifreeze button, and the control module receives the command to turn on the antifreeze button and executes the antifreeze action repeatedly.

[0087] The specific antifreeze measures are as follows:

[0088] A. When the first liquid level sensor 6 detects the liquid level, the control module first opens the drain valve 5 to drain the liquid;

[0089] B. When the first liquid level sensor 6 fails to detect the liquid level, the control module controls the drain valve 5 to close and the inlet valve 4 to open, and the U-shaped pipe 1 to replenish the liquid until the first liquid level sensor 6 detects the liquid level again, thus realizing the cycle of draining and replenishing the liquid.

[0090] It is worth noting that the actions of both the drain valve 5 and the inlet valve 4 have a certain time delay. There is a certain time interval from disconnection to complete disconnection, and similarly, there is a certain time interval from closing to complete closing. During the process of the drain valve 5 from disconnection to complete disconnection to closing to complete closing, and during the process of the inlet valve 4 from disconnection to complete disconnection to closing to complete closing, a certain liquid level difference can be formed, so as to achieve the effect of liquid flow in the U-shaped pipe 1; thus, liquid flow is realized in the U-shaped pipe 1, achieving the effect of antifreeze.

[0091] In other embodiments of the present invention, other heat preservation measures may be taken for the U-shaped tube to achieve the antifreeze function. The heat preservation measures include, but are not limited to, applying a heat preservation coating and an external heat preservation cover.

[0092] The alarm module is connected to the control module and is used to receive alarm commands from the control module and execute alarm actions.

[0093] Thirdly, embodiments of the present invention provide a control method for an anti-backflow fume device, which applies the anti-backflow fume system described above, and includes the following steps:

[0094] When the range hood is working, specifically:

[0095] Monitor whether there is liquid in U-shaped pipe 1. If liquid is detected, drain the liquid from U-shaped pipe 1.

[0096] The second liquid level sensor 7 monitors the liquid level in the U-shaped pipe 1. When the second liquid level sensor 7 detects a liquid level, it indicates that there is liquid in the U-shaped pipe 1. The second liquid level sensor 7 then sends a second liquid level monitoring signal to the control module. Based on the monitoring signal, the control module controls the drain valve 5 to open, thereby draining the liquid.

[0097] When the second liquid level sensor 7 does not detect the liquid level, it means that there is no liquid in the U-shaped pipe 1. Therefore, the second liquid level sensor 7 does not send a monitoring signal to the control module, and the drain valve 5 does not operate.

[0098] When the range hood is not working, specifically:

[0099] The U-shaped pipe 1 is used for replenishment. Liquid enters the U-shaped pipe 1 until the liquid in the U-shaped pipe 1 reaches the first preset liquid level.

[0100] The control module controls the inlet valve 4 to open, and the U-shaped pipe 1 is replenished with liquid through the inlet valve 4.

[0101] The first liquid level sensor 6 monitors the liquid level in the U-shaped pipe 1. When the first liquid level sensor 6 does not detect the liquid level, the control module still controls the inlet valve 4 to remain open. When the first liquid level sensor 6 detects the liquid level, the first liquid level sensor 6 sends a first liquid level monitoring signal to the controller, and the control module controls the inlet valve 4 to close.

[0102] In this embodiment, when using the automatic liquid replacement function, an automatic liquid replacement time point is set. When the automatic liquid replacement time point is reached, the liquid in the U-shaped pipe 1 is first discharged, and then the U-shaped pipe 1 is replenished with liquid.

[0103] The automatic liquid replacement time point is set by a timer. When the automatic liquid replacement time point is reached, the controller controls the drain valve 5 to open and drain the liquid in the U-shaped pipe 1. When the second liquid level sensor 7 can no longer detect the liquid level, the control module controls the drain valve 5 to close and the inlet valve 4 to open. When the first liquid level sensor 6 detects the liquid level signal, the control module controls the inlet valve 4 to close.

[0104] In this embodiment, when the range hood is not working, the liquid level is constantly monitored. If the liquid level is lower than a first preset liquid level, liquid is added to the U-shaped pipe 1. The first preset liquid level is set at the exhaust end of the U-shaped pipe 1. This method can achieve the synchronous gain of back pressure resistance and back pressure of the U-shaped pipe 1, that is, it can resist the pressure of backflow of oil fumes. Specifically, when liquid is injected into the U-shaped pipe 1 to form a seal, the pressure on both sides of the U-shaped pipe 1 is balanced. However, once the number of households using range hoods in the residential building increases, the backflow pressure of oil fumes on the main exhaust pipe side increases, and the liquid level at the exhaust end of the U-shaped pipe 1 will decrease under the influence of pressure, affecting the sealing effect. Therefore, when the liquid level is lower than the monitoring value of the first liquid level sensor 6, liquid is added to the U-shaped pipe 1. At this time, due to the influence of the pressure of the main exhaust pipe, the newly added liquid will flow to the air inlet end of the U-shaped pipe 1, and the liquid level difference between the air inlet end and the exhaust end will gradually increase, that is, the water level pressure difference will gradually increase until a new balance is reached, resisting the pressure of backflow of oil fumes from the main exhaust pipe.

[0105] In this embodiment, the liquid level is monitored at all times. When the liquid level is greater than or equal to the second preset liquid level, the control module issues an alarm command and simultaneously controls the U-shaped pipe 1 to drain the liquid until the liquid level is less than the second preset liquid level. The second preset liquid level is higher than the first preset liquid level, and the second preset liquid level is set at the air inlet end of the U-shaped pipe 1.

[0106] In this embodiment, when the range hood is not working, the status of the antifreeze button is determined. When the antifreeze button is in the closed state, the U-shaped pipe 1 performs liquid replenishment and drainage operations.

[0107] In this embodiment, when the range hood is not working for a long time, the automatic liquid replacement mechanism can be set to automatically replace the liquid in the U-shaped pipe 1 according to the automatic liquid replacement time point, so as to prevent the liquid in the U-shaped pipe 1 from deteriorating and affecting the environment.

[0108] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0109] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0110] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0111] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. A device for preventing backflow of cooking fumes, characterized in that, include: U-shaped pipe (1), the air inlet end of the U-shaped pipe (1) is connected to the exhaust pipe of the range hood, and the exhaust end of the U-shaped pipe (1) is connected to the exhaust manifold; An inlet pipe (2) is located at the bottom of the U-shaped pipe (1) and communicates with the inside of the U-shaped pipe (1) through the inlet end of the U-shaped pipe (1). An inlet valve (4) is provided on the inlet pipe (2). The injection of sealing liquid from the inlet pipe (2) into the U-shaped pipe (1) can prevent the backflow of oil fumes in the exhaust main pipe from entering the exhaust pipe of the range hood. A drain pipe (3) is located at the bottom of the U-shaped pipe (1) and communicates with the inside of the U-shaped pipe (1) through the drain end of the U-shaped pipe (1). A drain valve (5) is provided on the drain pipe (3). An automatic liquid changing mechanism is electrically connected to the inlet valve (4) and the outlet valve (5) respectively. The U-shaped pipe (1) can perform automatic liquid discharge and automatic liquid inlet under the control of the automatic liquid changing mechanism. The U-shaped pipe (1) is also equipped with a first liquid level sensor (6), a second liquid level sensor (7) and a third liquid level sensor (8); The first liquid level sensor (6) is located on the outer wall of the exhaust end of the U-shaped pipe (1). The first liquid level sensor (6) is used to monitor the liquid level inside the U-shaped pipe (1). When the liquid level at the exhaust end of the U-shaped pipe (1) is lower than the monitoring value of the first liquid level sensor (6), liquid is added to the U-shaped pipe (1), so that the newly added liquid flows to the air inlet of the U-shaped pipe (1). The liquid level difference between the air inlet and exhaust end of the U-shaped pipe (1) gradually increases until a new equilibrium is reached to resist the pressure of backflow of oil fumes from the main exhaust pipe. The second liquid level sensor (7) is located at the bottom of the U-shaped pipe (1) and is used to monitor whether there is liquid in the U-shaped pipe (1); The third liquid level sensor (8) is located on the outer wall of the air inlet end of the U-shaped pipe (1), and the third liquid level sensor (8) is used to monitor the maximum liquid level limit in the U-shaped pipe (1).

2. The anti-backflow fume device according to claim 1, characterized in that, The automatic fluid replacement mechanism is a timer.

3. A backflow prevention system for cooking fumes, characterized in that, Includes an automatic liquid replacement module, a control module, and an anti-backflow fume device as described in any one of claims 1-2; The anti-backflow fume device is connected to the range hood and the exhaust main pipe respectively, and is used to prevent backflow fume from the exhaust main pipe into the range hood through the liquid discharge and liquid inlet of the U-shaped pipe (1); The automatic liquid replacement module is used to set the automatic liquid replacement time point and control the U-shaped pipe (1) to perform automatic liquid discharge and automatic liquid inlet according to the automatic liquid replacement time point; The control module is connected to the automatic liquid replacement module, the drain valve (5) of the anti-backflow fume device, and the inlet valve (4) respectively, and is used to control the operation of the anti-backflow fume device.

4. The anti-backflow fume system according to claim 3, characterized in that, The anti-backflow fume system also includes an antifreeze module and an alarm module; The antifreeze module includes an antifreeze button, which is connected to the control module and is used to input an antifreeze command to the control module. The control module is used to control the liquid inlet and outlet of the U-shaped pipe (1) according to the antifreeze command; The control module is also used to output alarm commands to the alarm module; The alarm module is connected to the control module and is used to execute alarm actions according to the alarm instructions of the control module.

5. A control method for an anti-backflow fume device, implemented using the anti-backflow fume system according to any one of claims 3-4, characterized in that, Includes the following steps: While the range hood is in operation, monitor in real time whether there is liquid inside the U-shaped pipe (1); If liquid is detected, control the U-shaped pipe (1) to perform a drainage operation until the liquid in the U-shaped pipe (1) is completely drained; When the range hood is not working, perform a liquid replenishment operation on the U-shaped pipe (1) until the liquid level in the U-shaped pipe (1) reaches the first preset liquid level.

6. The control method for the anti-backflow fume device according to claim 5, characterized in that, Also includes: When the set automatic liquid replacement time point is reached, the U-shaped pipe (1) is first controlled to perform a liquid drainage operation, and then the U-shaped pipe (1) is controlled to perform a liquid replenishment operation; wherein, the automatic liquid replacement time point is within the time period when the range hood is not working.

7. The control method for the anti-backflow fume device according to claim 5, characterized in that, When the range hood is not working, the liquid level in the U-shaped pipe (1) is monitored in real time. When the liquid level in the U-shaped pipe (1) is lower than the first preset liquid level, the U-shaped pipe (1) is controlled to perform a liquid replenishment operation until the liquid level in the U-shaped pipe (1) reaches the first preset liquid level. The first preset liquid level is set at the exhaust end of the U-shaped pipe (1).

8. The control method for the anti-backflow fume device according to claim 7, characterized in that, The liquid level in the U-shaped pipe (1) is monitored in real time. When the liquid level in the U-shaped pipe (1) is greater than or equal to the second preset liquid level, the U-shaped pipe (1) is controlled to perform a liquid discharge operation until the liquid level in the U-shaped pipe (1) is less than the second preset liquid level. The second preset liquid level is higher than the first preset liquid level and the second preset liquid level is set at the air inlet end of the U-shaped pipe (1).

9. The control method for the anti-backflow fume device according to claim 5, characterized in that, Determine the status of the antifreeze button when the range hood is not in use; When the antifreeze button is in the closed state, control the U-shaped pipe (1) to perform the drainage operation first and then the replenishment operation.

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