Backflow preventer and drainage judgment method of backflow preventer

Abstract

The backflow preventer comprises a valve body, and a water inlet cavity, a middle cavity and a water outlet cavity are sequentially formed in the valve body; a water escape valve is further arranged at the bottom end of the valve body; the one-way valve bank is arranged between the water inlet cavity and the middle cavity and between the middle cavity and the water outlet cavity, the antifouling filter screen comprises a filter screen part with an opening in one end, a fixing ring is arranged at the opening end of the filter screen part, the filter screen part is arranged outside the first spring in a sleeving mode, and the first spring is arranged in the middle cavity. The fixing ring is detachably mounted on the rod sleeve; a dirt scraping piece is further arranged on the portion, between the middle cavity and the water outlet cavity, of the anti-fouling filter screen. By means of the antifouling filter screen arranged on the one-way valve bank close to the water outlet cavity, foreign matter flowing back into the middle cavity can be prevented from getting close to the first spring and clamping the first spring, and subsequent normal opening, closing and using of the one-way valve bank close to the water outlet cavity are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of backflow preventers, and in particular relates to a backflow preventer and a method for judging water leakage of a backflow preventer. Background Art

[0002] A low-resistance backflow preventer is usually provided with two one-way valve groups with an intermediate cavity between the two one-way valve groups. While ensuring the forward flow of pressurized water in the pipeline, the low-resistance backflow preventer can also intercept the water flowing back from the downstream and any foreign matter it may carry in the intermediate cavity, preventing it from passing through the water inlet cavity and affecting the upstream water end, causing backflow pollution.

[0003] However, when the existing low-resistance backflow preventer intercepts backflow sewage and foreign matter in the middle chamber, if the foreign matter that is flushed back is large, the foreign matter may be stuck in the spring of the one-way valve group near the water outlet chamber, so that the opening and closing of the one-way valve group is hindered or even cannot be opened normally, thereby affecting the normal use of the equipment. Summary of the invention

[0004] The present invention aims at solving the problems in the prior art and proposes the following technical solutions:

[0005] The present invention provides a backflow preventer, comprising:

[0006] A valve body, wherein a water inlet cavity, an intermediate cavity and a water outlet cavity are sequentially arranged inside the valve body; a drain valve is also arranged at the bottom end of the valve body;

[0007] A one-way valve assembly, the one-way valve assembly is arranged between the water inlet chamber and the middle chamber and between the middle chamber and the water outlet chamber, the one-way valve assembly comprises a valve seat arranged inside the valve body, a rod sleeve is arranged in the middle of the valve seat, a valve stem is movably inserted in the rod sleeve, a valve cover is arranged at one end of the valve stem, a protrusion is arranged at the other end of the valve stem, and a spring is arranged at a section outside the valve stem and between the protrusion and the rod sleeve;

[0008] An anti-fouling filter screen, the anti-fouling filter screen comprises a filter screen portion with an opening at one end, and a fixing ring is provided at the open end of the filter screen portion, the filter screen portion is sleeved on the outside of the spring 1, and the fixing ring is detachably mounted on the rod sleeve;

[0009] A dirt scraping member is also arranged on the anti-fouling filter screen between the middle cavity and the water outlet cavity.

[0010] As a preferred embodiment of the above technical solution, the scraper includes a mounting shaft rotatably arranged on the filter part, the mounting shaft is arranged at one end of the filter part away from the opening, an extension rod is fixedly arranged on the mounting shaft, the extension rod is arranged on the outside of the filter part, a cleaning brush is also arranged at one end of the extension rod close to the outer wall of the filter part, the cleaning brush is in contact with the outer wall of the filter part, a spiral blade is also fixedly arranged on the end of the mounting shaft, and the spiral blade is rotated only when backflow occurs and is pushed by the water flow.

[0011] As a preferred embodiment of the above technical solution, it also includes a limiting member, which includes a ratchet and a fixed frame, the ratchet fixed sleeve is arranged on a section of the installation shaft extending into the filter part, the fixed frame is arranged on one end of the filter part close to the installation shaft, the ratchet is located on the inner side of the fixed frame, and a fixing column 1 is also arranged on the inner side wall of the fixing frame, and a pawl is movablely sleeved on the fixing column 1, and the pawl cooperates with the ratchet so that the ratchet can only rotate in one direction.

[0012] As a preferred embodiment of the above technical solution, a second fixing column is further provided on the inner side wall of the fixing frame, a third spring is provided on the second fixing column, and the other end of the third spring is connected to a pawl.

[0013] As a preferred embodiment of the above technical solution, a second installation groove for a fixing ring to be inserted into is provided at one end of the rod sleeve close to the anti-fouling filter screen, elastic blocks are symmetrically provided on the side wall of the fixing ring, and a slot for the elastic block to be inserted into is provided at the position of the second installation groove corresponding to the elastic block.

[0014] As a preferred embodiment of the above technical solution, the fixing ring is provided with an inner groove, the elastic block is movably arranged in the inner groove, a second spring is arranged in the inner groove, and the other end of the second spring is connected to the elastic block.

[0015] As a preferred embodiment of the above technical solution, it also includes an alarm component, which includes a pressure sensor, a data processor and an alarm. The pressure sensor is arranged in the water inlet chamber, the middle chamber and the water outlet chamber. The pressure sensor is connected to the external data processor signal, and the data processor is connected to the alarm signal.

[0016] The present invention also provides a method for judging water leakage of a backflow preventer, using any of the backflow preventers described above, comprising the following steps:

[0017] S1. The alarm sounds to warn of backflow and determines that the one-way valve group near the water outlet chamber is abnormal;

[0018] S2, backflow water and foreign matter enter the middle cavity, and the drain valve drains water and sewage;

[0019] S3, the spiral blades are driven by the backflow of water to rotate;

[0020] S4. The extension rod rotates to prevent impurities from getting stuck on the one-way valve group near the water outlet chamber, so that sewage can be discharged smoothly;

[0021] S5. The backflow water pressure gradually decreases, and the one-way valve group located near the water inlet chamber opens to allow the water flow to continue to flow downstream.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention can prevent particulate matter, impurities or foreign matter in the liquid from directly contacting the spring one by providing an anti-fouling filter outside the spring one of the two one-way valve groups, thereby preventing these substances from getting stuck in the spring one. The anti-fouling filter provided on the one-way valve group near the water outlet chamber can prevent foreign matter that flows back into the middle chamber from approaching the spring one and getting stuck in the spring one, thereby ensuring the subsequent normal opening and closing and use of the one-way valve group near the water outlet chamber.

[0024] (2) The present invention provides a scraper. When backflow occurs, the spiral blades are pushed by the backflow water to rotate. The rotation of the spiral blades drives the installation shaft, the extension rod and the cleaning brush to rotate synchronously. At this time, the impurities entering the middle cavity are intercepted by the anti-fouling filter outside the spring. During the sewage discharge process, the rotating extension rod stirs in the middle cavity, which can prevent the impurities from being stuck on the one-way valve group near the water outlet chamber, and the sewage is discharged smoothly. The cleaning brush can clean the filter part, clean the impurities deposited on the filter part, ensure the smooth flow of the filter, and ensure the water pressure balance inside and outside the anti-fouling filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 What is shown is a schematic diagram of the structure of the backflow preventer in the embodiment;

[0026] Figure 2 What is shown is an overall schematic diagram of the anti-fouling filter screen in the embodiment;

[0027] Figure 3 It shows Figure 1 A schematic diagram of the structure enlargement in the middle;

[0028] Figure 4 The diagram shows the front view of the anti-fouling filter and the dirt scraping member in the embodiment;

[0029] Figure 5 The figure shows a schematic side view of the structure of the ratchet wheel and the pawl in the embodiment;

[0030] Figure 6 What is shown is a schematic diagram of the structure of the elastic block and the fixing ring in the embodiment;

[0031] : Illustration numerals: 10, valve body; 11, water inlet chamber; 12, water outlet chamber; 13, intermediate chamber; 14, drain valve; 15, pressure sensor; 21, valve seat; 210, rod sleeve; 2111, mounting groove one; 2112, mounting groove two; 22, valve cover; 23, valve stem; 24, spring one; 30, anti-fouling filter; 31, filter part; 32, fixing ring; 320, inner groove; 321, spring two; 33, elastic block; 41, spiral blade; 42, mounting shaft; 43, extension rod; 44, cleaning brush; 51, ratchet; 52, fixing frame; 53, fixing column one; 54, ratchet; 55, fixing column two; 56, spring three. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0033] Example 1

[0034] like Figure 1 As shown, Figure 1 What is shown is a schematic diagram of the structure of the backflow preventer in the embodiment;

[0035] The device includes:

[0036] The valve body 10 has a water inlet chamber 11, an intermediate chamber 13 and a water outlet chamber 12 arranged therein in sequence; a drain valve 14 is also arranged at the bottom of the valve body 10, and the drain valve 14 is connected to the water inlet chamber 11, the intermediate chamber 13 and the water outlet chamber 12 respectively;

[0037] A one-way valve group is arranged between the water inlet chamber 11 and the middle chamber 13 and between the middle chamber 13 and the water outlet chamber 12. The one-way valve group includes a valve seat 21 arranged inside the valve body 10, a rod sleeve 210 is arranged in the middle of the valve seat 21, a valve stem 23 is movably inserted in the rod sleeve 210, a valve cover 22 is arranged at one end of the valve stem 23, a protrusion is arranged at the other end of the valve stem 23, and a spring 24 is arranged on the outside of the valve stem 23 and a section between the protrusion and the rod sleeve 210.

[0038] The rod sleeve 210 is disposed in the middle portion of the valve seat 21 , and three structural ribs are disposed on the valve seat 21 and connected to the rod sleeve 210 .

[0039] like Figure 3 As shown, Figure 3 It is shown that Figure 1 A schematic diagram of the structure enlargement in the middle;

[0040] An installation groove 2111 is provided at one end of the rod sleeve 210 close to the anti-fouling filter screen 30 , and one end of the spring 24 is connected to the installation groove 2111 .

[0041] As is known, when the backflow preventer is in use, water flows from the water inlet chamber 11 to the water outlet chamber 12, and the two groups of one-way valve groups are opened in sequence to transfer water to the pipeline behind the water outlet chamber 12. If downstream water and foreign matter flow back, the one-way valve group arranged near the water outlet chamber 12 is closed first. When the one-way valve group leaks or is blocked by foreign matter and fails to be effectively closed, the backflow water and foreign matter will enter the middle chamber 13. At this time, the backflow water will be intercepted by the one-way valve group arranged near the water inlet chamber 11 to prevent backflow pollution, and the drain valve 14 will discharge the backflow sewage until the backflow water pressure becomes smaller, and the one-way valve group arranged near the water inlet chamber 11 opens to allow the water flow to continue to flow downstream.

[0042] like Figure 1 , Figure 2 As shown, Figure 1 What is shown is a schematic diagram of the structure of the backflow preventer in the embodiment; Figure 2 What is shown is an overall schematic diagram of the anti-fouling filter screen in the embodiment;

[0043] The device also includes:

[0044] The anti-fouling filter 30 includes a filter portion 31 with an opening at one end, and a fixing ring 32 is provided at the open end of the filter portion 31. The filter portion 31 is sleeved on the outside of the spring 24, and the fixing ring 32 is detachably mounted on the rod sleeve 210.

[0045] The anti-fouling filter 30 disposed outside the spring 1 24 of the two one-way valve groups can prevent particulate matter, impurities or foreign matter in the liquid from directly contacting the spring 1 24 , thereby preventing these substances from getting stuck in the spring 1 24 .

[0046] The anti-fouling filter 30 arranged on the one-way valve group near the water outlet chamber 12 can prevent foreign matter that flows back into the middle chamber 13 from approaching the spring 24 and jamming the spring 24, thereby ensuring the subsequent normal opening and closing and use of the one-way valve group near the water outlet chamber 12.

[0047] like Figure 1 , Figure 3 As shown, Figure 1 What is shown is a schematic diagram of the structure of the backflow preventer in the embodiment; Figure 3 It shows Figure 1 A schematic diagram of the structure enlargement in the middle;

[0048] The rod sleeve 210 is provided with a second installation groove 2112 for the fixing ring 32 to be inserted into at one end close to the anti-fouling filter 30. The side wall of the fixing ring 32 is symmetrically provided with elastic blocks 33. The second installation groove 2112 is provided with a slot for the elastic block 33 to extend into at a position corresponding to the elastic block 33.

[0049] The anti-fouling filter 30 can be detachably installed by setting the second installation groove 2112, the elastic block 33 and the card slot. Specifically, the elastic block 33 is retractable, and the fixing ring 32 can smoothly enter the second installation groove 2112 when the elastic block 33 is in the contracted state. After the fixing ring 32 enters the second installation groove 2112, the elastic block 33 is reset and extends into the card slot to achieve engagement.

[0050] like Figure 6 As shown, Figure 6 What is shown is a schematic diagram of the structure of the elastic block and the fixing ring in the embodiment;

[0051] The fixing ring 32 is provided with an inner groove 320 , and the elastic block 33 is movably provided in the inner groove 320 . A second spring 321 is provided in the inner groove 320 , and the other end of the second spring 321 is connected to the elastic block 33 .

[0052] In the initial state, the elastic block 33 is pushed out of the inner groove 320 by the second spring 321. Applying external force on the elastic block 33 can make the elastic block 33 compress the second spring 321 and enter the inner groove 320, thereby realizing the elastic expansion and contraction setting of the elastic block 33.

[0053] like Figure 1 , Figure 4 , Figure 5 As shown, Figure 1 What is shown is a schematic diagram of the structure of the backflow preventer in the embodiment; Figure 4 The diagram shows the front view of the anti-fouling filter and the dirt scraping member in the embodiment; Figure 5 The figure shows a schematic side view of the structure of the ratchet wheel and the pawl in the embodiment;

[0054] A scraper is also provided on the anti-fouling filter 30 located between the middle cavity 13 and the water outlet cavity 12, and the scraper includes a mounting shaft 42 rotatably arranged on the filter portion 31, the mounting shaft 42 is arranged on the end of the filter portion 31 away from the opening, an extension rod 43 is fixedly arranged on the mounting shaft 42, the extension rod 43 is arranged on the outside of the filter portion 31, and a cleaning brush 44 is also provided on the end of the extension rod 43 close to the outer wall of the filter portion 31, and the cleaning brush 44 is in contact with the outer wall of the filter portion 31, and a spiral blade 41 is also fixedly arranged on the end of the mounting shaft 42, and the spiral blade 41 is only rotated by the water flow when backflow occurs.

[0055] Through the scraper, when backflow occurs, the spiral blade 41 will be pushed by the backflow water to rotate, and the rotation of the spiral blade 41 drives the installation shaft 42, the extension rod 43 and the cleaning brush 44 to rotate synchronously. At this time, the impurities entering the middle cavity 13 are intercepted by the anti-fouling filter 30 on the outside of the spring 24. During the sewage discharge process, the rotating extension rod 43 stirs in the middle cavity 13, which can prevent impurities from being stuck on the one-way valve group 12 near the water outlet cavity, and the sewage is discharged smoothly. The cleaning brush 44 can clean the filter part 31, clean the impurities deposited on the filter part 31, ensure the smooth flow of the filter, and ensure the water pressure balance inside and outside the anti-fouling filter 30.

[0056] It also includes a limiting member, which includes a ratchet 51 and a fixed frame 52. The ratchet 51 is fixedly sleeved on a section of the installation shaft 42 extending into the filter part 31. The fixed frame 52 is arranged on one end of the filter part 31 close to the installation shaft 42. The ratchet 51 is located on the inner side of the fixed frame 52. A fixed column 53 is also arranged on the inner side wall of the fixed frame 52. A pawl 54 is movably sleeved on the fixed column 53. The pawl 54 cooperates with the ratchet 51 so that the ratchet 51 can only rotate in one direction.

[0057] By providing the ratchet 51, the fixing frame 52 and the pawl 54, the spiral blade 41 can be pushed by the backflow water flow to rotate only when backflow occurs, so that the scraping member is activated only when sewage is discharged.

[0058] A second fixing column 55 is also provided on the inner side wall of the fixing frame 52 . A third spring 56 is provided on the second fixing column 55 . The other end of the third spring 56 is connected to the pawl 54 .

[0059] The spring three 56 is provided to limit the position of the pawl 54 so that the pawl 54 is always close to the ratchet 51 and cooperates with the ratchet 51 .

[0060] Example 2

[0061] The difference from Example 1 is that the device further includes:

[0062] The alarm component includes a pressure sensor 15, a data processor and an alarm. The pressure sensor 15 is arranged in the water inlet chamber 11, the middle chamber 13 and the water outlet chamber 12. The pressure sensor 15 is connected to the external data processor signal, and the data processor is connected to the alarm signal.

[0063] The pressure sensor 15 detects the pressure in the water inlet chamber 11, the middle chamber 13 and the water outlet chamber 12. The data processor obtains the pressure difference value based on the pressure value and feeds it back to the alarm. The alarm determines whether to sound an alarm based on the set pressure difference threshold.

[0064] The alarm component can issue a warning when backflow or water leakage occurs in the device, so as to remind the operators at the first time and ensure that they can take prompt measures to understand the water leakage and prevent the spread of pollution.

[0065] Example 3

[0066] The backflow preventer leakage judgment method adopts the backflow preventer in the above embodiment, comprising the following steps:

[0067] S1, the alarm sounds an alarm, reminding that backflow occurs, and it is determined that the one-way valve group near the water outlet chamber 12 is abnormal;

[0068] S2, backflow water and foreign matter enter the middle chamber 13, and the drain valve 14 drains water and sewage;

[0069] S3, the spiral blade 41 is driven by the backflow water flow to rotate;

[0070] S4, the extension rod 43 rotates to prevent impurities from getting stuck on the one-way valve group 12 near the water outlet chamber, so that sewage can be discharged smoothly;

[0071] S5. The backflow water pressure gradually decreases, and the one-way valve group arranged near the water inlet chamber 11 opens to allow the water flow to continue to flow downstream.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them.

Claims

1. A backflow preventer, characterized in that: include: A valve body (10), wherein a water inlet chamber (11), an intermediate chamber (13) and a water outlet chamber (12) are sequentially arranged inside the valve body (10); a drain valve (14) is also arranged at the bottom end of the valve body (10); A one-way valve assembly, the one-way valve assembly being arranged between a water inlet chamber (11) and an intermediate chamber (13) and between the intermediate chamber (13) and a water outlet chamber (12), the one-way valve assembly comprising a valve seat (21) arranged inside a valve body (10), a rod sleeve (210) being arranged in the middle of the valve seat (21), a valve stem (23) being movably inserted in the rod sleeve (210), a valve cover (22) being arranged at one end of the valve stem (23), a protrusion being arranged at the other end of the valve stem (23), and a spring (24) being arranged at a section outside the valve stem (23) and between the protrusion and the rod sleeve (210); An anti-fouling filter (30), the anti-fouling filter (30) comprising a filter portion (31) with an opening at one end, and a fixing ring (32) is provided at the open end of the filter portion (31), the filter portion (31) is sleeved on the outside of the spring (24), and the fixing ring (32) is detachably mounted on the rod sleeve (210); A dirt scraping member is also provided on the anti-fouling filter screen (30) located between the middle cavity (13) and the water outlet cavity (12).

2. The backflow preventer according to claim 1, characterized in that: The scraper comprises a mounting shaft (42) rotatably mounted on the filter part (31), the mounting shaft (42) being mounted on an end of the filter part (31) away from the opening, an extension rod (43) being fixedly mounted on the mounting shaft (42), the extension rod (43) being mounted on the outside of the filter part (31), a cleaning brush (44) being also mounted on the end of the extension rod (43) close to the outer wall of the filter part (31), the cleaning brush (44) being in contact with the outer wall of the filter part (31), and a spiral blade (41) being fixedly mounted on the end of the mounting shaft (42), the spiral blade (41) being rotated only when backflow occurs due to the push of the water flow.

3. The backflow preventer according to claim 2, characterized in that: The invention also comprises a limiting member, wherein the limiting member comprises a ratchet (51) and a fixing frame (52); the ratchet (51) is fixedly sleeved on a section of the installation shaft (42) extending into the filter part (31); the fixing frame (52) is arranged on an end of the filter part (31) close to the installation shaft (42); the ratchet (51) is located on the inner side of the fixing frame (52); a fixing column (53) is also arranged on the inner side wall of the fixing frame (52); a ratchet (54) is movably sleeved on the fixing column (53); the ratchet (54) cooperates with the ratchet (51) so that the ratchet (51) can only rotate in one direction.

4. The backflow preventer according to claim 3, characterized in that: A second fixing column (55) is also provided on the inner side wall of the fixing frame (52), and a third spring (56) is provided on the second fixing column (55), and the other end of the third spring (56) is connected to the pawl (54).

5. The backflow preventer according to claim 1, characterized in that: A second mounting groove (2112) for the fixing ring (32) to be inserted into is arranged at one end of the rod sleeve (210) close to the anti-fouling filter screen (30), elastic blocks (33) are symmetrically arranged on the side wall of the fixing ring (32), and a slot for the elastic block (33) to be inserted into is arranged at a position on the second mounting groove (2112) corresponding to the elastic block (33).

6. The backflow preventer according to claim 5, characterized in that: The fixing ring (32) is provided with an inner groove (320), the elastic block (33) is movably arranged in the inner groove (320), a second spring (321) is arranged in the inner groove (320), and the other end of the second spring (321) is connected to the elastic block (33).

7. The backflow preventer according to claim 1, characterized in that: It also includes an alarm component, which includes a pressure sensor (15), a data processor and an alarm. The pressure sensor (15) is arranged in the water inlet chamber (11), the middle chamber (13) and the water outlet chamber (12). The pressure sensor (15) is connected to an external data processor signal, and the data processor is connected to the alarm signal.

8. A method for judging water leakage of a backflow preventer, using the backflow preventer according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, the alarm sounds an alarm, reminding that backflow occurs, and determining that the one-way valve group near the water outlet chamber (12) is abnormal; S2, backflow water and foreign matter enter the middle chamber (13), and the drain valve (14) drains water and sewage; S3, the spiral blade (41) is driven by the backflowing water flow to rotate; S4, the extension rod (43) rotates to prevent impurities from getting stuck on the one-way valve group (12) near the water outlet chamber, so that sewage can be discharged smoothly; S5. The backflow water pressure gradually decreases, and the one-way valve group located near the water inlet chamber (11) opens to allow the water flow to continue to flow downstream.

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