A magnetic swing backflow preventer

Abstract

The present invention discloses a magnetic swing backflow preventer, which is provided with a valve body, and the inner wall of the valve body is provided with a valve seat; it includes: a fixed baffle, which is fixedly provided at one end of the movable rocker, and a first valve flap is provided on the side of the fixed baffle, and a sealing gasket is pasted on the side of the first valve flap; a valve cover, which is provided on the top of the valve body, and a ball valve is provided on the top side of the valve body; a protective cover, which is provided on the side of the valve body by bolts, and a magnet base is provided on the inner side of the protective cover; a rocker shaft, which passes through the other end of the movable rocker, and a movable rocker is fixedly connected to the end of the rocker shaft. The magnetic swing backflow preventer adopts a series swing check structure, and the sealing force is provided by the magnet and the valve flap deadweight to ensure reliable sealing, and the tension spring is reset to provide a closing torque when positive pressure is provided, and the valve is closed before the reverse pressure, thereby improving safety. In addition, the magnet is external, and the magnetic force is not affected by impurities in the medium, and scaling is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of backflow preventers, in particular to a magnetic swing-type backflow preventer. Background Art

[0002] At present, backflow preventers are divided into three categories: double check valve backflow preventers, low resistance backflow preventers and pressure reducing backflow preventers. The backflow prevention facilities are selected according to the degree of pollution hazard of drinking water backflow. The double check valve backflow preventer is a device with two independent check valves connected in series to prevent the reverse flow of pressurized water in the pipeline; the low resistance backflow preventer is composed of an inlet check valve, an outlet check valve and a drain valve in the middle cavity, etc., and can still block the backflow in the event of failure of the seal of its check valve or seal to prevent the backflow of the inlet medium from being polluted by backflow; in the backflow condition, the middle cavity is always connected to the atmosphere, and the pressure (head) loss is less than 0.04MPa when the average flow rate in the pipe is 2m / s; the pressure reducing backflow preventer is composed of two independently acting check valves and a drain valve, and is a hydraulic control device for preventing backflow that controls the opening and closing of the drain valve through the pressure difference generated by the inlet check valve;

[0003] Backflow preventers are commonly used in water pipes. They can automatically open when water is supplied to allow water to flow through, and can automatically close when water supply is stopped, playing a role in preventing backflow. They must be installed compulsorily in the national standard GB50015-2019 "Design Standard for Building Water Supply and Drainage". They can not only prevent the pollution hazards of drinking water backflow, but also reduce the waste of electrical energy in water supply equipment. Therefore, backflow preventers are widely used in existing water systems. However, existing backflow preventers have the following disadvantages in actual use:

[0004] 1. The most traditional backflow preventer is mainly based on a spring structure. The most traditional spring structure must have an initial spring force to ensure positive pressure sealing. When the backflow preventer is opened, the resistance increases after the spring is compressed. When v=2m / s, the water loss is much greater than 30kPa, which wastes electricity and does not solve the actual needs of users. It is increasingly unacceptable to users.

[0005] 2. The low-resistance backflow preventer is also designed with a spring structure. The low-resistance spring structure mainly reduces the positive pressure sealing parameters, which sacrifices the safety performance of the backflow preventer. However, it solves the actual needs of users and is accepted by the market, but its scope of use is limited.

[0006] 3. The swing-type backflow preventer is designed with a connecting rod torsion spring structure. The compression stroke of the torsion spring is small, and the water-facing surface area of ​​the swing structure is small, which can reduce water loss and achieve low resistance. It is a low-resistance backflow preventer, but it sacrifices the safety performance of the backflow preventer, and the structure is quite complex, making it difficult to implement.

[0007] 4. The track-type backflow preventer is designed with a variable track structure, but because the spring force is provided by a torsion spring, it is difficult to make and install the torsion spring, and it is difficult to ensure the accuracy and life of the torsion spring force, and it is also difficult to detect. The valve seat is made of plastic material, which is easy to deform. If it is changed to stainless steel material, track processing is very difficult. It is only suitable for large-scale special machine production. The cost of small-scale production is too high, and the market is very small if it cannot be sold.

[0008] 5. The magnet backflow preventer is designed with a magnet lifting structure, but the magnet is built-in, there are impurities in the medium, the magnet is easy to absorb slag, and the valve is full of iron parts, it is difficult to isolate the magnetism, the magnet suction is unstable, the lifting structure has a large water-facing surface area, and the flow resistance coefficient is larger than that of the swing structure, that is, the water loss is large.

[0009] In view of the above problems, in order to solve the contradiction between the need for greater sealing force when fully closed (higher safety) and less water loss when fully open (actual needs of users), domestic and foreign countries have conducted difficult research for a long time. The track-type backflow preventer is based on foreign technology, but it has not been widely used due to its high price and small batch size. It also involves international patent protection issues. The principle of the magnet-type backflow preventer is good, but the lifting structure has a large water-facing surface area, and the compression spring is also facing the flow channel. The water loss is sometimes large and sometimes small, sometimes exceeding 30KPa, the magnet suction is unstable, and there are hidden safety risks. Therefore, it is urgent to carry out innovative design based on the original backflow preventer. Summary of the invention

[0010] The object of the present invention is to provide a magnetic swing backflow preventer to solve the problems raised in the above background technology that the torsion spring force accuracy and life are difficult to ensure, detection is also difficult, and the plastic material used for the valve seat is easy to deform.

[0011] To achieve the above object, the present invention provides the following technical solution: a magnetic swing backflow preventer, provided with a valve body, the inner wall of the valve body is provided with a valve seat, and a movable rocker is movably provided inside the valve body;

[0012] include:

[0013] A fixed baffle, fixedly arranged at one end of the movable rocker, a first valve flap is arranged on the side of the fixed baffle, a sealing gasket is pasted on the side of the first valve flap, and a second valve flap is movably installed in the valve body on the side of the first valve flap;

[0014] A valve cover is arranged on the top of the valve body, and a ball valve is arranged on the top side of the valve body;

[0015] A protective cover is arranged on the side of the valve body by bolts, a magnet base is arranged on the inner side of the protective cover, a water outlet magnet is installed above the magnet base, and the end of the magnet base is fixedly connected to one end of the return spring;

[0016] A rocker shaft passes through the other end of the movable rocker, a movable rocker is fixedly connected to the end of the rocker shaft, a fixing groove is provided at one end of the movable rocker close to the magnet base, and an adjusting screw passes through the inner side of the fixing groove.

[0017] Preferably, the first valve flap and the second valve flap both form a rotating structure with the interior of the valve body through a movable rocker and a rocker arm shaft, and the first valve flap and the second valve flap have the same specifications. Therefore, when the water flow impacts the first valve flap and the second valve flap, it can respectively drive the two valve flaps to rotate and open, thereby facilitating the passage of water. After the water supply is stopped, the first valve flap and the second valve flap can rotate in opposite directions to achieve the closure of the water supply channel. At this time, the valve flap can be pressed against the sealing surface of the valve seat to achieve the highest standard requirement of 20kpa positive pressure sealing, thereby meeting the safety requirements.

[0018] Preferably, the water outlet magnet and the adjusting screw are arranged in one-to-one correspondence, and the thickness of the water outlet magnet is smaller than the depth of the fixing groove. When the movable rocker arm contacts the magnet base, it can drive the adjusting screw to adsorb to the water outlet magnet, thereby improving the sealing after the valve disc is closed.

[0019] Preferably, the distance between the water outlet magnet and the adjusting screw is adjustable, and the adjusting screw and the movable rocker arm are threadedly connected. By rotating the adjusting screw, the position on the movable rocker arm can be changed, thereby adjusting the distance from the water outlet magnet, and adapting to different working conditions by adjusting the suction force.

[0020] Preferably, the movable rocker arm and the movable rocker arm are coaxially arranged, and two movable rocker arms, magnet bases and movable rocker arms are each provided. Therefore, when the valve disc is impacted and rotated, the movable rocker arm can be driven to rotate synchronously through the rocker arm shaft, thereby driving the reset spring to stretch, and the backflow preventer is opened and separated from the rocker arm plane. There is no suction after it is fully opened. After the backflow preventer is opened, there is no resistance in the flow direction of the medium and no water loss, achieving the highest standard requirement of less than 30kpa water loss at a flow rate of 2m / s, meeting the user's actual application and reducing electricity requirements.

[0021] Compared with the prior art, the invention has the following beneficial effects: the magnetic swing backflow preventer adopts a series swing check structure, the sealing force is provided by the magnet and the valve disc deadweight, the sealing is reliable, the tension spring is reset, the closing torque is provided when the positive pressure is provided, the valve is closed before the reverse pressure, the safety is improved, and the magnet is external, the magnetic force is not affected by impurities in the medium, and scaling is prevented. The specific contents are as follows:

[0022] 1. When the water flow hits the first valve disc and the second valve disc, it can drive the two valve discs to rotate and open respectively. During the rotation of the valve disc, the movable rocker arm can be driven to rotate synchronously through the rocker arm shaft. Since the reset spring and the water outlet magnet are both arranged outside the valve body, the positive opening pressure is much greater than 20kPa. Therefore, it will not be affected by impurities in the medium during use, preventing scaling and affecting the effect of the parts themselves.

[0023] 2. Further, when the movable rocker arm contacts the magnet base, the sealing of the valve disc after closing can be further ensured by adjusting the adsorption between the screw and the water outlet magnet, and the position of the screw on the movable rocker arm can be changed by rotating the adjusting screw to adjust the distance between the screw and the water outlet magnet, so that the suction force can be adjusted to meet different water supply requirements;

[0024] 3. The initial magnetic force of the first valve disc in the closed state is 20KPa, and the magnetic force disappears in the open state, and the stretching spring force is 5KPa. The water loss is 8KPa, which is the resistance 3KPa + the stretching spring force 5KPa generated by the backflow preventer structure. The initial magnetic force of the second valve disc in the closed state is 7KPa, and the magnetic force disappears in the open state, and the stretching spring force is 5KPa. The water loss is 8KPa, which is the resistance 3KPa + the stretching spring force 5KPa generated by the backflow preventer structure. The water loss of the two valve discs is 16KPa;

[0025] 4. Magnetic swing structure, in which the water-facing surface area of ​​the swing structure is only 46% of that of the lifting structure, so the flow resistance coefficient is low. When v=2m / s, the water loss through the valve is only 3kPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the front cross-section structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the top view structure of the present invention;

[0028] Figure 3 It is a front view structural schematic diagram of the present invention;

[0029] Figure 4 It is a side view structural schematic diagram of the present invention;

[0030] Figure 5 It is a schematic diagram of the front cross-section structure of the movable rocker arm of the present invention.

[0031] In the figure: 1. valve body; 2. valve seat; 3. sealing gasket; 4. first valve disc; 5. fixed baffle; 6. movable rocker; 7. valve cover; 8. ball valve; 9. protective cover; 10. water outlet magnet; 11. magnet base; 12. return spring; 13. adjusting screw; 14. movable rocker arm; 15. rocker arm shaft; 16. second valve disc; 17. fixing groove. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] See also Figure 1-5 The present invention provides a technical solution: a magnetic swing backflow preventer, which is provided with a valve body 1, a valve seat 2 is provided on the inner wall of the valve body 1, and a movable rocker 6 is movably provided inside the valve body 1;

[0034] The invention comprises: a fixed baffle 5, which is fixedly arranged at one end of a movable rocker 6, a first valve flap 4 is arranged on the side of the fixed baffle 5, a sealing gasket 3 is pasted on the side of the first valve flap 4, and a second valve flap 16 is movably installed in the valve body 1 on the side of the first valve flap 4; a valve cover 7, which is arranged on the top of the valve body 1, and a ball valve 8 is arranged on the top side of the valve body 1; a protective cover 9, which is arranged on the side of the valve body 1 by bolts, a magnet base 11 is arranged on the inner side of the protective cover 9, and a water outlet magnet 10 is installed above the magnet base 11, and the magnet base The end of 11 is fixedly connected to one end of the return spring 12; the rocker shaft 15 passes through the other end of the movable rocker 6, and the end of the rocker shaft 15 is fixedly connected to the movable rocker 14, and the movable rocker 14 is provided with a fixing groove 17 at one end close to the magnet base 11, and the inner side of the fixing groove 17 passes through an adjusting screw 13. The valve seat 2 and the flow channel are designed with full diameter and wide inner cavity to ensure the valve flow capacity and reduce water loss. The structure is compact and easy to maintain. The front and rear check valves are installed separately, and the online maintenance is convenient and the space is wide.

[0035] like Figure 1-4 As shown, the first valve flap 4 and the second valve flap 16 both form a rotating structure with the interior of the valve body 1 through the movable rocker 6 and the rocker shaft 15, and the first valve flap 4 and the second valve flap 16 have the same specifications. When the first valve flap 4 and the second valve flap 16 are impacted by the water flow, they can be opened respectively to allow the water flow to pass through, and the first valve flap 4 and the second valve flap 16 can drive the movable rocker 6 to rotate on the valve body 1 through the rocker shaft 15, and a flat rubber valve flap is used, which has no obstruction, good sealing effect, no leakage, durability and long service life. After the water supply is stopped, the valve flap can be driven to rotate in the opposite direction to seal the inside of the valve body 1 through the gravity of the valve flap itself and the resilience of the return spring 12, so the hydraulic loss is small, the closing torque is provided when the positive pressure is provided, and the valve is closed before the reverse pressure, thereby improving safety;

[0036] like Figure 3 and Figure 5As shown, the water outlet magnet 10 and the adjusting screw 13 are arranged in one-to-one correspondence, and the thickness of the water outlet magnet 10 is less than the depth of the fixing groove 17. When the valve flap is in a closed state, the sealing inside the valve body 1 can be further ensured by the adsorption of the adjusting screw 13 and the water outlet magnet 10; the distance between the water outlet magnet 10 and the adjusting screw 13 is adjustable, and the adjusting screw 13 and the movable rocker arm 14 are threadedly connected, and the distance between the adjusting screw 13 and the water outlet magnet 10 can be changed by rotating the adjusting screw 13, and the suction force can be adjusted to adapt to different working conditions; the movable rocker arm 14 and the movable rocker arm 6 are coaxially arranged, and the movable rocker arm 14, the magnet base 11 and the movable rocker arm 6 are each provided with two, and when the movable rocker arm 6 rotates, the movable rocker arm 14 can be driven to rotate synchronously through the rocker arm shaft 15, thereby driving the reset spring 12 to stretch, and driving the movable rocker arm 14 to separate from the magnet base 11.

[0037] Working principle: Figure 1-5 As shown, the backflow preventer is two independent series-connected swing check structures, which are used in the main pipeline of the system. When one of the two check valves leaks, the other check valve seals to prevent the medium from flowing into the pipeline. It has high safety and reliability and plays a role in preventing backflow pollution.

[0038] The pipeline pressure acts on the valve disc to push open the valve. The pipeline water inlet chamber pressure is P1, the middle chamber pressure is P2, and the water outlet chamber pressure is P3. When P1-P2≥7.0kPa, the water inlet check valve opens, and P2-P3≥7.0kPa, the water outlet check valve opens, and the valve opens. The valve is designed with a reset spring 12. When P1-P2<7.0kPa, the water inlet check valve is closed under the action of the spring force, and P2-P3<7.0kPa, the water outlet check valve is closed to achieve positive pressure sealing;

[0039] After the first valve flap 4 and the second valve flap 16 are rotated and opened, the movable rocker arm 14 can be driven to rotate synchronously through the rocker arm shaft 15 to achieve the separation between the movable rocker arm 14 and the magnet base 11, and then drive the reset spring 12 to stretch. In this way, after the water supply is stopped, the inside of the valve body 1 can be sealed by the gravity of the valve flap itself and the resilience of the reset spring 12, and the movable rocker arm 14 can contact the magnet base 11 again, and the sealing can be further ensured by the adsorption between the adjusting screw 13 and the water outlet magnet 10. At the same time, the magnet base 11 is designed with a waist-shaped groove, which can adjust the position of the valve flap when closed to ensure that the valve is sealed reliably.

[0040] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A magnetic swing backflow preventer, comprising a valve body (1), an inner wall of the valve body (1) being provided with a valve seat (2), and a movable rocker (6) being movably provided inside the valve body (1); It is characterized in that include: A fixed baffle (5) is fixedly arranged at one end of the movable rocker (6), a first valve flap (4) is arranged on the side of the fixed baffle (5), a sealing gasket (3) is adhered to the side of the first valve flap (4), and a second valve flap (16) is movably installed in the valve body (1) on the side of the first valve flap (4); A valve cover (7) is arranged on the top of the valve body (1), and a ball valve (8) is arranged on the top side of the valve body (1); A protective cover (9) is arranged on the side of the valve body (1) by means of bolts, a magnet base (11) is arranged on the inner side of the protective cover (9), a water outlet magnet (10) is installed above the magnet base (11), and the end of the magnet base (11) is fixedly connected to one end of a return spring (12); A rocker shaft (15) passes through the other end of the movable rocker (6); a movable rocker (14) is fixedly connected to the end of the rocker shaft (15); a fixing groove (17) is formed at one end of the movable rocker (14) close to the magnet base (11); and an adjusting screw (13) passes through the inner side of the fixing groove (17); The first valve flap (4) and the second valve flap (16) both form a rotating structure with the interior of the valve body (1) via a movable rocker (6) and a rocker arm shaft (15), and the first valve flap (4) and the second valve flap (16) have the same specifications; The water outlet magnet (10) and the adjusting screw (13) are arranged in one-to-one correspondence, and the thickness of the water outlet magnet (10) is smaller than the depth of the fixing groove (17).

2. A magnetic swing backflow preventer according to claim 1, characterized in that: The distance between the water outlet magnet (10) and the adjusting screw (13) is adjustable, and the adjusting screw (13) and the movable rocker arm (14) are threadedly connected.

3. The magnetic swing backflow preventer according to claim 1, characterized in that: The movable rocker arm (14) and the movable rocker lever (6) are coaxially arranged, and two of each of the movable rocker arm (14), the magnet base (11) and the movable rocker lever (6) are arranged.

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