Flue fireproof check valve

Abstract

The utility model discloses a flue fireproof check valve, including the casing of metal material, valve rod and valve plate, the casing is provided with the smoke outlet, the smoke outlet is equipped with the smoke pipe interface, still include the linear drive mechanism of drive valve plate close the smoke outlet, and the pressure compact guiding structure of top pressure valve plate makes valve plate close valve working surface closely, the utility model discloses flue fireproof check valve through linear drive mechanism drive valve plate shift and close the smoke outlet, guarantee valve plate close valve working surface closely through the pressure compact guiding structure, make flue fireproof check valve not because of the oil dirt pollution leads to check valve close valve failure, not only can close the valve when the fire occurs, but also effectively prevented the flue gas of public flue from check valve backflow into the kitchen.

Description

Technical Field

[0001] This utility model relates to the field of kitchen equipment technology, and in particular to a flue fireproof backflow preventer valve. Background Technology

[0002] The flue fireproof backflow preventer is connected to the range hood. When the range hood is working, it opens the smoke guide duct to direct the fumes generated by the stove into the common flue; when the range hood stops working, it closes the smoke guide duct. In the event of a fire, closing the smoke guide duct prevents fumes from the common flue from entering the room.

[0003] Current flue fireproof backflow preventers all use fan-blade baffles. The baffle opens when airflow is applied and closes due to gravity when there is no airflow. Some also open or close the flue by rotating the baffle. This structure is initially flexible and provides a good seal. However, after a period of use, grease from the flue gas gradually accumulates inside the valve and adheres to the fan-blade baffle, causing obstruction. The stickiness of the grease not only makes it difficult to open the baffle, but the repeated contact and separation between the blades and the exhaust outlet causes the grease to become increasingly unevenly distributed at the outlet, making it difficult for the valve to close completely and affecting its backflow prevention effect. This allows flue gas from the common flue to enter the room through the exhaust outlet, polluting the indoor environment. In the event of a fire, it cannot effectively prevent open flames and toxic fumes from entering the room, leading to the spread of toxic gases and the fire. Utility Model Content

[0004] The purpose of this utility model is to provide a novel and unique flue gas fireproof backflow preventer valve that is easy to use and can effectively prevent flue gas backflow; the specific technical solution is as follows: A flue fireproof backflow preventer valve includes a housing, a valve stem, and a valve plate made of metal; the housing is provided with a smoke exhaust port, and a smoke pipe interface is provided outside the smoke exhaust port; it also includes a linear drive mechanism for driving the valve plate to close the smoke exhaust port; and a pressing guide structure for pressing the valve plate to make the valve plate tightly adhere to the valve closing working surface.

[0005] Furthermore, the valve plate driving mechanism includes a driving part and a valve stem; the valve stem is fixedly connected to the valve plate, or threadedly connected to it, or sleeved to it.

[0006] Furthermore, the driving component of the drive unit is a DC motor; the drive shaft of the DC motor is connected to the valve stem via a coupling; the valve stem is a lead screw, and a nut that mates with the lead screw is fixedly connected to the valve plate.

[0007] Furthermore, the drive unit is mounted outside the housing.

[0008] Furthermore, the housing is provided with a valve plate slot that fits the valve plate with a clearance.

[0009] Furthermore, the outer end of the valve stem is provided with a shaft groove for external manual rotation of the valve stem.

[0010] This utility model of a flue fireproof backflow preventer valve uses a linear drive mechanism to drive the valve plate to shift and close the smoke exhaust port; the pressing guide structure ensures that the valve plate is tightly attached to the valve closing working surface, so that the flue fireproof backflow preventer valve will not fail to close due to oil pollution; not only can it close the valve in the event of a fire, but it also effectively prevents the smoke from the public flue from flowing back into the kitchen through the backflow preventer valve. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the closed state structure of the flue fireproof backflow preventer valve of this utility model. Figure 1 ; Figure 2 This is a schematic diagram of the closed state structure of the flue fireproof backflow preventer valve of this utility model. Figure 2 ; Figure 3 This is a schematic diagram of the open state structure of the flue fireproof backflow preventer valve of this utility model; Figure 4 This is a schematic diagram of the circuit principle of the flue fireproof backflow preventer valve of this utility model.

[0012] In the diagram: 1. Housing; 101. Smoke pipe interface; 102. Smoke outlet; 2. Valve plate; 3. Lead screw; 4. Nut; 5. Lead screw seat; 6. DC motor; 7. Coupling; 8. Spring pressure plate assembly; 9. Temperature sensor. Detailed Implementation

[0013] The present invention will be described more fully below with reference to embodiments. The present invention can be embodied in many different forms and should not be construed as being limited to the exemplary embodiments described herein.

[0014] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” may be used herein to describe the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, an element described as being “down” of another element or feature would be positioned “up” of that other element or feature. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0015] like Figure 1 , Figure 2As shown, the flue fireproof backflow preventer valve in this embodiment includes a housing 1 and a valve plate 2; the housing is provided with a smoke exhaust port 102 for the passage of flue gas, and a smoke pipe interface 101 for fixing and connecting the exhaust pipe of the range hood is provided outside the smoke exhaust port; the housing 1 is made of metal plate and is square columnar in shape; it can also be cylindrical.

[0016] The valve plate is made of thin metal plate with a thickness of 1-2 mm. Due to the large diameter of the exhaust port, using a thin plate for the valve plate can not only reduce costs but also help to reduce the weight of the valve, making the valve lightweight.

[0017] The flue fireproof backflow preventer also includes a linear drive mechanism that drives the valve plate to close the smoke exhaust port; the valve plate opens or closes the smoke exhaust port by linear movement; the resistance from oil stains is small, and some oil stains will be removed during the linear movement of the valve plate.

[0018] To reduce flue gas leakage when the valve is closed, a pressure-guiding structure is installed to ensure the valve plate is tightly pressed against the exhaust port when the valve is closed. The plane containing the inner wall of the exhaust port of the housing is referred to as the valve-closing working surface. Of course, to meet fire protection requirements, the housing, valve plate, screw nut, connecting parts, and fasteners are all made of metal.

[0019] like Figure 3 As shown in the figure, a clamping and guiding structure is provided; spring pressure plate assemblies 8 are provided on both the left and right sides of the valve plate; the spring pressure plate assembly is elongated, with its length parallel to the direction of movement along the valve plate. The spring pressure plate assembly consists of a pressure plate frame and a spring pressure plate; the short bottom side of the trapezoidal spring pressure plate presses against the valve plate, and the spring pressure plate is fixed by the pressure plate frame fixed to the side wall. The spring pressure plate can also take other forms, such as: a wavy bottom surface with several pressing points in contact with the valve plate; or an arc shape fixed under the pressure plate frame to form a clamping and guiding structure that can achieve both clamping and guiding functions.

[0020] like Figure 2As shown, the power element of the driving part is the DC motor 6; switching between valve opening and valve closing can be realized by changing the current direction, which features simple control; the control circuit of the motor adopts the prior art. The driving shaft of said DC motor is fixedly connected to one end of the screw rod 3 through a coupling 7; the other end of the screw rod is fixedly connected to a bearing in the screw rod seat 5; the screw rod seat 5 is fixedly arranged on the side wall of the housing; the motor drives the screw rod to rotate forward or reversely; the nut 4 matched with said screw rod moves forward or backward along with the rotation of the screw rod; the valve plate fixedly connected to the nut is driven by the nut to open or close the smoke exhaust port. The central axis of the screw rod shall be parallel to the working face for valve closing and parallel to the central plane in the left-right direction of the housing; it is preferably arranged in the central plane in the left-right direction of the housing, so that the valve structure is symmetrical left and right. The valve plate may be rectangular, or race track-shaped. The difference between the width of the valve plate and the diameter of the smoke exhaust port shall be greater than 10 mm. During installation, the valve plate is moved to the valve closing position, and after the valve plate completely fits the working face for valve closing, the fastening bolts connecting the mounting seat of the nut on the screw rod and the valve plate are tightened; then the valve plate is moved to the valve opening position, and after the valve plate completely fits the working face for valve closing, the fastening bolts connecting the screw rod seat and the side plate of the housing are tightened; so that the valve plate can always completely fit the working face for valve closing during the valve opening and closing process.

[0021] Said driving element is preferably installed outside said housing; so as to avoid contact with open fire or high-temperature flue gas in the public flue, which would cause damage to the driving element.

[0022] Said housing may further be provided with a valve plate slit that is in clearance fit with said valve plate; when the valve is opened, the valve plate can extend out of the housing through the valve plate slit without occupying the internal space of the housing, so the size of the housing can be reduced. The gap between the valve plate slit and the valve plate shall be less than 0.5 mm; so that the flue gas leakage of the valve is lower than the value specified in the standard. Preferably, one side of the valve plate slit is aligned with the working face for valve closing; a protective plate is arranged on the side away from the working face for valve closing; the protective plate is parallel to the working face for valve closing, and cooperates with the inner wall of the housing on the side of the valve plate away from the working face for valve closing to form sealing grooves for the two side edges of the valve plate; the flue gas in the valve must pass through the sealing grooves before flowing out from the valve plate slit, which is beneficial to further reducing the flue gas leakage of the valve.

[0023] In order to manually close the valve when the motor fails, the outer end of said valve rod is provided with a shaft slot for assisting manual rotation of the valve rod. The shaft slot may be a straight slot, a cross slot or an inner hexagonal slot; when the electric system fails, a screwdriver can be inserted into the shaft slot, and rotating the screwdriver can push the valve plate to the closed state of the smoke exhaust port, avoiding the problem that the valve cannot be closed due to the failure of the electric system; of course, rotating the screwdriver can also push the valve plate from the closed state of the smoke exhaust port to the open state, so as not to affect normal smoke exhaust.

[0024] In order to realize linked operation with the range hood, an electric control part can be additionally arranged; the power supply of the electric control part is commercial power, and the power switch can be shared with the range hood, which simplifies circuit wiring.

[0025] like Figure 4 As shown, the electronic control section consists of a microcontroller, a switching power supply, a motor control circuit, a temperature sensing circuit, a mains power detection circuit, and an alarm circuit; the circuits in each part are all common circuits and adopt the circuits described in the prior art.

[0026] The alarm circuit can be a buzzer alarm circuit or a warning light alarm circuit. The temperature sensing circuit converts the temperature into an analog temperature signal that is compatible with the microcontroller voltage via temperature sensor 9. The analog input of the microcontroller is connected to the analog temperature signal to obtain the temperature value inside the valve body.

[0027] The mains voltage detection circuit converts the mains voltage into a voltage signal that is compatible with the analog input of the microcontroller.

[0028] A switching power supply converts AC power or rechargeable battery voltage into a motor drive voltage and power supply that is compatible with the motor, such as a 12V DC power supply; or an intelligent control power supply that is compatible with the microcontroller voltage, such as a 5V DC power supply. It also includes a charging circuit for the rechargeable battery.

[0029] The motor control circuit includes a motor forward / reverse control circuit and a motor load current detection circuit. The motor control circuit can obtain the motor's operating status through the motor load current detection circuit. When the valve is fully open or fully closed, the lead screw cannot rotate, and the load current surges. After the microcontroller detects that the motor circuit is experiencing stall current through the motor load current detection circuit, it stops outputting the drive signal, and the motor stops rotating.

[0030] When the range hood power switch is turned on, the range hood is powered on. The induction coil connected to the power cord acts as a current sensor, converting the power current into a low-voltage AC signal. The microcontroller obtains the range hood's current signal through the range hood current detection circuit. When the detected power current is greater than 350 mA (the range hood lighting circuit current is less than 100 mA), it is determined that the range hood motor is working. The motor control circuit then controls the DC motor to drive the valve plate to move and open the exhaust port, allowing the range hood to discharge fumes into the common flue. When the detected power current is less than 350 mA, it is determined that the range hood motor has stopped. The motor control circuit then controls the DC motor to drive the valve plate to move and close the exhaust port.

[0031] In the event of a sudden power outage during the operation of the range hood, the power supply to the electronic control unit switches to rechargeable battery power, ensuring that the valve promptly switches from the open to the closed state after the power outage.

[0032] When the valve is open, if high-temperature flue gas appears in the flue, the microcontroller obtains an abnormal temperature signal through the temperature sensor. For example, if the temperature sensor detects that the temperature inside the valve exceeds 150 degrees Celsius, the microcontroller controls the motor to drive the valve plate to close the flue gas outlet through the motor control circuit.

[0033] The above examples are only used to illustrate this utility model. In addition, there are many other different implementation methods, which can be conceived by those skilled in the art after understanding the concept of this utility model. Therefore, they will not be listed one by one here.

Claims

1. A flue fireproof backflow preventer valve, comprising a housing, a valve stem, and a valve plate made of metal; the housing is provided with a smoke exhaust port, and a smoke pipe interface is provided outside the smoke exhaust port; characterized in that, It also includes a valve plate, a valve plate drive mechanism for driving the valve plate to close the exhaust port; and a pressing guide structure for pressing the valve plate so that the valve plate is tightly attached to the working surface of the closed valve; the thickness of the valve plate is between 1 and 2 millimeters.

2. The fire damper check valve for flues as claimed in claim 1, characterized in that, The valve plate drive mechanism includes a drive unit and a valve stem; the valve stem is fixedly connected to the valve plate, or threadedly connected or sleeved.

3. The fire damper check valve for flues as claimed in claim 2, characterized in that, The driving component of the drive unit is a DC motor; the drive shaft of the DC motor is connected to the valve stem via a coupling; the valve stem is a lead screw, and a nut that mates with the lead screw is fixedly connected to the valve plate.

4. The fire damper check valve of claim 3, wherein The DC motor is mounted outside the housing.

5. The flue fireproof check valve as described in claim 1, characterized in that, The housing is provided with a valve plate slot that fits the valve plate with a clearance.

6. The fire damper check valve for flues as claimed in claim 4, characterized in that, The outer end of the valve stem is provided with a shaft groove for external manual rotation of the valve stem.

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