An anti-backdraft device and a gas water heater

Abstract

The present invention relates to the technical field of gas appliances, and discloses an anti-backdraft device and a gas water heater, which includes a pipe body. The pipe body includes a section of horizontal straight pipe and a section of L-shaped elbow pipe. The horizontal straight pipe is communicated with the L-shaped elbow pipe, and the outer port of the horizontal straight pipe is the smoke outlet. A Venturi tube is arranged in the lower section of the L-shaped elbow pipe. There is a gap between the outer wall of the Venturi tube and the inner wall of the lower section of the L-shaped elbow pipe. A side through hole is arranged on the pipe wall of the L-shaped elbow pipe corresponding to the middle section of the Venturi tube. The edge of the bottom port of the Venturi tube is connected to the edge of the bottom port of the L-shaped elbow pipe. The bottom port of the Venturi tube serves as the smoke inlet, and an anti-backdraft plate is arranged at the upper port of the Venturi tube. When there is backdraft from the outside and the anti-backdraft device is sealed to a certain extent, the outside backdraft can be bypassed at the same time; the water heater is protected from shutting down, and the low-temperature cold air is prevented from backflowing and impacting the water, resulting in cracking of the water tank.

Description

Technical Field

[0001] The present invention relates to the technical field of gas appliances, and particularly relates to an anti-backdraft device and a gas water heater. Background Art

[0002] For existing gas water heaters, each brand adopts a mechanical anti-backflow device. When there is backdraft from the outside, the passage is closed to protect the water heater and stop it from working. In fact, for the existing device, the principle of the water heater is to stop working for protection, but the actual mechanical anti-backflow device fails to close the passage tightly. When cold air from the outside backflows for a long time, the pressure in the upper cavity of the anti-backdraft device increases, and cold air backflows through the unsealed gap, and extremely low-temperature cold air directly impacts the water tank of the water heater, resulting in the water tank cracking. Summary of the Invention

[0003] The purpose of the present invention is to provide an anti-backdraft device and a gas water heater to solve the problem that the water tank of the gas water heater cracks due to the impact of cold air backflow at low temperature.

[0004] To achieve the above purpose, the present invention is implemented by adopting the following technical solutions:

[0005] An anti-backdraft device includes a pipe body. The pipe body includes a section of horizontal straight pipe and a section of L-shaped bent pipe. The horizontal straight pipe is communicated with the L-shaped bent pipe, and the outer port of the horizontal straight pipe is the smoke outlet; a Venturi tube is arranged in the lower section of the L-shaped bent pipe. There is a gap between the outer wall of the Venturi tube and the inner wall of the lower section of the L-shaped bent pipe. A side through hole is arranged on the pipe wall of the L-shaped bent pipe corresponding to the middle section of the Venturi tube; the edge of the bottom port of the Venturi tube is connected to the edge of the bottom port of the L-shaped bent pipe. The bottom port of the Venturi tube is used as the smoke inlet, and an anti-backdraft plate is arranged at the upper port of the Venturi tube.

[0006] Preferably, a plurality of circular ventilation holes with equal size and arranged at equal distances are arranged at the end of the horizontal straight pipe.

[0007] Preferably, the anti-backdraft plate is hinged on the anti-backdraft device.

[0008] Preferably, the L-shaped bent pipe is connected to the horizontal straight pipe by a socket connection method.

[0009] A gas water heater is connected to the smoke outlet at the top of the gas water heater body by using the anti-backdraft device as described above.

[0010] Preferably, when there is no reverse draft, the gas water heater operates normally. The blower of the gas water heater rotates to form a wind pressure for exhausting smoke, pushing open the anti-reverse draft plate, and discharging through the L-shaped elbow and the horizontal straight pipe. Under the action of the Venturi tube, a negative pressure is formed on its outer side, and a small amount of air is inhaled from the side through holes to prevent the exhausted smoke generated by the gas water heater from leaking outside. When affected by reverse draft, the wind pressure generated by the rotation of the blower of the gas water heater is constant. If it is lower than the reverse draft wind pressure, the gas water heater will be protected and stop working. When affected by reverse draft, it pours in through the horizontal straight pipe and the L-shaped elbow, causing the anti-reverse draft plate to close. As the reverse draft lasts for a long time, the pressure in the cavity increases, and pressure is relieved through the side through holes provided on the L-shaped elbow to prevent the reverse draft from entering the interior of the gas water heater and impacting the water tank.

[0011] The beneficial effects of the present invention are:

[0012] The present invention discloses an anti-reverse draft device and a gas water heater. The anti-reverse draft device is designed based on the Venturi tube ejection principle, which can realize normal exhaust of smoke and form a negative pressure at the side through holes to prevent the normal exhaust of smoke from leaking outside the side through holes. When there is an external reverse draft, under the action of the wind, the anti-reverse draft device closes, and at the same time, pressure is relieved through the side through holes. The anti-reverse draft device can be used for the exhaust of gas water heaters, gas heating furnaces, etc. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram when the gas water heater of the present invention operates normally without reverse draft;

[0014] Figure 2 It is a schematic structural diagram when the gas water heater of the present invention operates normally under reverse draft;

[0015] In the figure, 1 - gas water heater; 2 - L-shaped elbow; 3 - horizontal straight pipe; 4 - circular ventilation hole; 5 - Venturi tube; 6 - anti-reverse draft plate; 7 - side through hole. Detailed Embodiments

[0016] The following is further described with reference to the drawings. As Figure 1 shown, an anti-reverse draft device includes a pipe body. The pipe body includes a section of horizontal straight pipe 3 and a section of L-shaped elbow 2. The L-shaped elbow 2 is connected to the horizontal straight pipe 3 by means of socket connection. The horizontal straight pipe 3 is communicated with the L-shaped elbow 2. The outer port of the horizontal straight pipe 3 is the smoke outlet; a Venturi tube 5 is arranged inside the lower section of the L-shaped elbow 2. There is a gap between the outer wall of the Venturi tube 5 and the inner wall of the lower section of the L-shaped elbow 2. Four side through holes 7 are provided on the pipe wall of the L-shaped elbow 2 corresponding to the middle section of the Venturi tube 5; the edge of the bottom port of the Venturi tube 5 is connected to the edge of the bottom port of the L-shaped elbow 2. The bottom port of the Venturi tube 5 serves as the smoke inlet, and an anti-reverse draft plate 6 is arranged at the upper port of the Venturi tube 5. A plurality of circular ventilation holes 4 with equal size and equally spaced arrangement are provided at the end of the horizontal straight pipe 3.

[0017] A gas water heater 1 is connected to the smoke exhaust port at the top of the gas water heater 1 body by using the anti-backdraft device as described above. Combined Figure 1 , when there is no backdraft, the gas water heater 1 works normally. The fan of the gas water heater 1 rotates to form a wind pressure for smoke exhaust, pushing open the anti-backdraft plate 6, and discharging through the L-shaped elbow 2 and the horizontal straight pipe 3. Under the action of the Venturi tube 5, a negative pressure is formed on its outer side, and a small amount of air is inhaled from the side through hole 7 to prevent the smoke exhaust generated by the gas water heater 1 from leaking out. Combined Figure 2 , when affected by backdraft, the wind pressure generated by the rotation of the fan of the gas water heater 1 is certain. If it is lower than the backdraft wind pressure, the gas water heater 1 will be protected and stop working; when affected by backdraft, it pours in through the horizontal straight pipe 3 and the L-shaped elbow 2, closing the anti-backdraft plate 6. With the long-term backdraft, the pressure in the cavity increases accordingly, and the side through hole 7 provided on the L-shaped elbow 2 is used for pressure relief to prevent the backdraft from entering the inside of the gas water heater 1 and impacting the water tank.

[0018] Certainly, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. An anti-backdraft device, comprising a pipe body, characterized in that, The pipe body includes a section of horizontal straight pipe and a section of L-shaped bent pipe. The horizontal straight pipe is connected and communicated with the L-shaped bent pipe. The outer port of the horizontal straight pipe is the smoke outlet. A Venturi tube is arranged in the lower section of the L-shaped bent pipe. There is a gap between the outer wall of the Venturi tube and the inner wall of the lower section of the L-shaped bent pipe. A side through hole is arranged on the pipe wall of the L-shaped bent pipe corresponding to the middle section of the Venturi tube. The edge of the bottom port of the Venturi tube is connected to the edge of the bottom port of the L-shaped bent pipe. The bottom port of the Venturi tube serves as the smoke inlet, and an anti-backdraft plate is arranged at the upper port of the Venturi tube. The anti-backdraft device is connected to the smoke exhaust port at the top of the gas water heater body. When there is no backdraft, the gas water heater works normally. The fan of the gas water heater rotates to form a wind pressure for smoke exhaust, pushing open the anti-backdraft plate, and discharging through the L-shaped bent pipe and the horizontal straight pipe. Under the action of the Venturi tube, a negative pressure is formed outside it, and a small amount of air is inhaled from the side through hole to prevent the smoke exhaust generated by the gas water heater from leaking. When there is backdraft, the wind pressure generated by the rotation of the fan of the gas water heater is certain. If it is lower than the backdraft wind pressure, the gas water heater will be protected and stop working. When there is backdraft, it pours in through the horizontal straight pipe and the L-shaped bent pipe, causing the anti-backdraft plate to close. As the backdraft lasts for a long time, the pressure in the cavity increases, and the side through hole arranged on the L-shaped bent pipe is used for pressure relief to prevent the backdraft from entering the gas water heater and impacting the water tank.

2. The anti-backdraft device according to claim 1, characterized in that, A number of circular ventilation holes with equal size and arranged at equal distances are arranged on the end pipe wall of the horizontal straight pipe.

3. The anti-backdraft device according to claim 1, characterized in that, The anti-backdraft plate is hinged on the Venturi tube.

4. The anti-backdraft device according to claim 1, characterized in that, The L-shaped bent pipe is connected to the horizontal straight pipe by means of socket connection.

Images