Rotary pump for conveying a fluid
By introducing check valves and automatic valves into the rotary pump, the problems of fluid loss flow and noise are solved, and the efficiency and characteristic curve are improved, making it suitable for sewage lifting devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WILO SE
- Filing Date
- 2022-12-09
- Publication Date
- 2026-06-02
AI Technical Summary
Existing rotary pumps suffer from fluid loss during the exhaust process, which affects their characteristic curve and efficiency, and also have a high noise level. They are particularly prone to clogging the exhaust passage when conveying liquids containing solids.
A check valve and an automatic valve are introduced into the rotary pump. The check valve closes when fluid enters the pump chamber to prevent fluid loss. The automatic valve automatically opens and closes the exhaust passage when the air pressure changes to prevent air from entering or escaping.
It improves pump efficiency and characteristic curves, reduces noise levels, and minimizes the risk of solid blockage, expanding its application range, especially suitable for sewage lifting devices.
Smart Images
Figure CN116335955B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a rotary pump for conveying fluid, the rotary pump having: a pump housing forming a pump chamber; an impeller disposed in the pump chamber for conveying fluid; a suction opening disposed in the pump housing for drawing fluid into the pump chamber through the impeller; and an exhaust opening disposed in the pump housing behind the impeller relative to the suction opening. Background Technology
[0002] Rotary pumps are known from the prior art and are used to transport fluids by means of the rotation of an impeller. The fluid to be transported enters the pump chamber of the rotary pump through the suction opening, is captured by the rotating impeller, and is thus transported to the guide section (also known as the pressure pipe).
[0003] Rotary pumps are used as sewage pumps, especially in sewage lifting systems, due to their strong stability in handling liquids containing solids, where wastewater is typically collected in collection containers for intermediate storage. To ensure that fluid flows back into the pump chamber after each pumping cycle and to allow the rotary pump to operate efficiently, venting is necessary. For this purpose, venting openings are usually installed in the pump chamber, through which air can escape. These venting openings are typically located at the highest point of the pump chamber, and in vertically mounted rotary pumps, above the impeller.
[0004] When a rotary pump is in operation, an acceptable loss flow occurs through the vent opening due to the pressure difference between the higher pressure inside the pump chamber and the lower pressure on the side of the vent opening away from the pump chamber. This loss flow is typically diverted away from the pump via the vent line or returned to the collection container in a wastewater lifting unit. However, this loss flow has an adverse effect on the pump's characteristic curve. Summary of the Invention
[0005] Based on this, the object of the present invention is to improve a rotary pump and lifting device of the type described at the outset in such a way that the rotary pump or lifting device has an improved characteristic curve.
[0006] The object of the present invention is achieved by the features of a rotary pump for conveying fluids. Advantageous design options are given in the specific embodiments.
[0007] Accordingly, this objective is achieved by a rotary pump for conveying fluid, the rotary pump having:
[0008] The pump casing that forms the pump chamber;
[0009] An impeller, installed in the pump chamber, is used to transport fluid;
[0010] A suction opening located in the pump casing is used to draw fluid into the pump chamber via an impeller; and
[0011] A check valve is located in the pump housing behind the impeller relative to the suction opening. This check valve closes due to fluid entering the pump chamber and / or due to the dominant air pressure in the pump chamber, and allows air to escape from the pump chamber when open.
[0012] The fundamental point of this invention is that the pump chamber can be vented using a check valve, which leads to improved efficiency and a better characteristic curve. On the other hand, when fluid flow is generated by the operation of the impeller in the pump chamber and / or air pressure is generated in the pump chamber, the check valve closes the pump chamber after the air in the pump chamber escapes through it. With the proposed solution, lossy flow of fluid is prevented by the vent opening closed by the check valve, thus increasing the pump's characteristic curve while keeping the motor power constant. Similarly, the risk of blockage by fluid, especially solids in wastewater, in the vent passage connected to the check valve downstream of the vent opening is minimized, as no fluid flows through the vent passage during operation. Finally, such lossy flow in a pump with a vent opening also reduces the increased noise level known from the prior art.
[0013] As a result, the proposed rotary pump can be used, for example, as a wastewater pump for use downhole, to pump very low water levels without sacrificing head and / or reducing the characteristic curve. In this respect, the application range of the rotary pump is expanded because the proposed solution allows for pumping the remaining volume (including sediment) in the well to be reached further and deeper. In other words, the proposed solution is particularly useful in that the venting passage, which is otherwise regularly present, is equipped with a check valve that allows air to be vented from the pump chamber to pass through, but closes once the liquid to be pumped reaches the check valve.
[0014] In this regard, compared to pumps without check valves, the proposed rotary pump maintains a consistently high hydraulic efficiency even with a small head and a large volumetric flow rate of the fluid to be pumped. Furthermore, the generation of unwanted noise is avoided, thus enabling low-noise operation of the pump. Preferably, the rotary pump can be used in the hydraulic systems of buildings, such as in sewage lifting systems. Correspondingly, the fluid can contain solids, which can include any type of contaminant, such as dust, paper, feces, etc.
[0015] In a rotary pump, fluid is transported by the rotational motion of an impeller. Preferably, the impeller is connected to a drive motor via a motor shaft extending in the axial direction. During operation, fluid flows from the outside of the pump through a suction opening in the pump housing into the pump chamber where the rotating impeller is located. In addition to the tangential acceleration of the fluid, centrifugal force occurring in the radial direction is used to transport the fluid, thus the rotary pump is also called a centrifugal pump. Fluid is preferably transported from the pump chamber to a guide section (also called a pressure pipe). For venting purposes, the rotary pump has a check valve as a venting opening behind the impeller relative to the suction opening. Preferably, the check valve is located at the highest point of the pump chamber. The air escaping through the check valve may contain fluid components. The check valve is preferably located in the wall of the pump chamber. A vent passage may be connected to the check valve or the vent opening, which may lead to the rotary pump, the outside of the pump chamber, and / or into a collection container.
[0016] In many cases, the suction inlet of a rotary pump is located at the lowest point of the pump casing, allowing the pump to draw in as much fluid as possible without leaving a large amount of residual fluid below the suction inlet. In such a vertically arranged rotary pump, the axial direction of the motor shaft corresponds to the vertical direction. In a vertically arranged rotary pump, the check valve, as an venting port, preferably extends beyond the height at which the impeller is secured to the motor shaft. However, other designs and arrangements of the rotary pump are also possible, where the motor shaft extends horizontally. In the case of a horizontal arrangement, the suction inlet is generally not located at the lowest point of the pump casing. In the case of a horizontal arrangement, the check valve, as an venting port, is preferably located relative to the horizontal direction near the impeller's securing position on the motor shaft, and on the side of the impeller opposite to the suction inlet.
[0017] The check valve is preferably designed to self-open, for example, by being de-energized in this open position. This means that the check valve preferably opens itself when the fluid in the pump chamber decreases and / or the air pressure in the pump chamber drops, for example, below a threshold. Similarly, the check valve can then close when the air pressure in the pump chamber increases above a threshold. In this respect, the check valve can be designed to be a self-opening check valve. Fluid entering the pump chamber specifically means that the check valve closes when the pump chamber is almost completely, preferably completely, filled with fluid and / or when the side of the pump chamber opposite to the suction opening of the impeller is filled with fluid. Fluid entering the pump chamber can also mean that the check valve closes when a certain filling height is reached. A similar approach can be applied to the dominant air pressure in the pump chamber, i.e., the check valve closes when the air pressure exceeds a predetermined value. In other words, it is proposed that the fluid and / or air pressure in the pump chamber acts on the check valve and can cause the check valve to close when the filling height and / or such air pressure exceed the value. Preferably, the check valve is open due to gravity. In other words, the check valve preferably opens due to gravity.
[0018] According to a preferred embodiment, the check valve is designed as a check flap, flap valve, and / or ball valve. According to another preferred design, the check valve is designed to close when the fluid and / or air pressure in the pump chamber increases. Preferably, the check valve closes when the fluid and / or air pressure in the pump chamber exceeds a threshold and / or opens when it falls below a threshold.
[0019] According to another preferred design, the check valve is made of a buoyancy material, particularly plastic, elastomer, fluorinated elastomer, or rubber, and is fastened to the pump housing at its impeller-facing end. Preferably, the check valve undergoes a shape change for closing and opening. For example, the upper portion can close the airflow through the check valve, while the lower portion is fastened to the pump housing, and the intermediate portion connecting the upper and lower portions is designed to be flexible for pivoting the upper portion relative to the lower portion. To support this pivoting, the diameter or material thickness of the intermediate portion can be smaller than that of the upper and / or lower portions. Further preferably, the check valve is designed as a tab or lip and is particularly preferably fastened to the pump housing at its lower end.
[0020] In this regard, it has proven advantageous that the check valve is made of an elastomer. Rubber, particularly fluororubber (FKM), has proven advantageous. Alternatively, other fluorinated elastomers such as perfluororubber (FFKM), tetrafluoroethylene / propylene rubber (FEPM), and / or fluorinated silicone rubber (FVMQ) can also be used. The aforementioned materials have the advantage of particularly high resistance to chemicals, which is especially advantageous for sewage lifting devices due to the presence of feces. Furthermore, the mechanical properties of the materials (especially deformability and processability) are particularly suitable for manufacturing check valves. Additionally, the elastomer can be made from other elastic materials.
[0021] According to another preferred design, an annular space defined by the impeller and pump housing is formed behind the impeller relative to the suction opening, and a check valve is disposed in the annular space. The annular space may extend around the motor shaft and / or be formed above the impeller during continuous operation.
[0022] According to another preferred design, the rotary pump has an exhaust passage connected to a check valve, located away from the pump chamber, and an automatic valve disposed at the exhaust passage. This automatic valve allows air to escape from the pump chamber and prevents air from entering the pump chamber. The automatic valve allows air to pass unimpeded through the exhaust passage. When the automatic valve is open, air can escape from the pump chamber through the exhaust opening and the exhaust passage, thus achieving exhaust of the pump chamber. When the automatic valve is closed, no air can pass through the automatic valve and enter the pump chamber through the exhaust opening.
[0023] In the context of this invention, an automatic valve is particularly understood as a valve that opens and closes automatically without the need for auxiliary energy. In other words, the opening and closing operations of an automatic valve are not achieved by electrical energy, but by energy provided mechanically. The mechanical energy used to open and close the automatic valve can be provided by the valve itself and / or by the medium flowing through the automatic valve. Preferably, the automatic valve is designed to open and / or close due to the pressure difference between the valve inlet and outlet sides. Here, the valve inlet side refers to the side of the automatic valve facing the pump chamber at the exhaust port.
[0024] An automatic valve allows air to escape from the pump chamber, prompting the rotary pump to properly vent the chamber, allowing fluid to flow back into the pump chamber through the suction port after each pumping operation. Therefore, the automatic valve allows air to flow from the valve inlet to the valve outlet. The automatic valve ensures the rotary pump can deliver fluid with high hydraulic efficiency. Furthermore, the automatic valve prevents air from flowing into the pump chamber in the opposite direction, i.e., from outside the pump through the vent port. In other words, the valve prevents air from flowing from the valve outlet to the valve inlet.
[0025] According to a preferred improvement, the automatic valve is designed as a self-closing flap valve, a duckbill valve, and / or a hose-like valve with two protrusions that come into contact with each other during backflow and / or during return to the pump chamber.
[0026] Preferably, the self-closing flap valve is at least partially opened when the pressure on the valve inlet side corresponds to the pressure on the valve outlet side. More preferably, the flap of the flap valve is further opened by air flowing from the valve inlet side to the valve outlet side during pump venting and / or by fluid flowing out as a loss flow during pump operation. For example, if the pressure on the valve inlet side is lower than the pressure on the valve outlet side due to pump operation within a suitable characteristic range—i.e., low head and high volumetric flow rate of the fluid to be transported—the volumetric flow rate is reversed in a short time, thereby closing the flap valve. Preferably, the flap valve's shape rigidity allows it to fully open when the pressures before and after the flap valve are equal. The self-closing flap valve has the advantages of being very stable due to its simple construction and can be manufactured without significant costs.
[0027] The duckbill valve is preferably a check valve made of an elastic material, and its shape resembles a duck's bill. Preferably, the end of the duckbill valve corresponding to the valve inlet has a shape corresponding to the exhaust port. The other end of the duckbill valve (i.e., the end corresponding to the valve outlet) preferably has a flat shape. The duckbill valve is preferably designed to allow unrestricted airflow in the pump chamber through the exhaust port. If backflow occurs, causing air to flow from outside the pump into the pump chamber through the exhaust port for a short time, the valve closes, thereby preventing the backflow of fluid and air that may carry solids into the pump chamber. The advantages of the duckbill valve are that it closes even with a very small pressure difference between the valve inlet and outlet and has a very short response time.
[0028] A valve with two tabs preferably has a hose-like shape at the end corresponding to the valve inlet side and two tabs at the end corresponding to the valve outlet side. The tabs are preferably two opposing tab-like end blocks of the hose housing. Closure of the hose-like valve is preferably achieved such that, during backflow, the tabs of the hose-like valve press against each other, thereby sealing the cross-section of the hose. The tabs remain pressed against each other and the cross-section remains closed during backflow, thus preventing air from flowing into the pump chamber when pressure conditions reverse. The advantage of the hose-like valve is that it responds quickly and closes the cross-section even with a very small pressure difference between the valve inlet and outlet sides.
[0029] Rotary pumps are, in principle, suitable for conveying any fluid. Due to their stability relative to solids and chemicals, rotary pumps are particularly suitable for use as submersible pumps for sewage and / or wastewater. Sewage and / or wastewater submersible pumps are especially used for pumping dirty water, such as from floods, submerged construction pits, laundry rooms, mud pits, community habitats and / or garden ponds, seepage wells, and cellars, and are particularly suitable for pumping water of varying degrees of contamination, such as stones, mud, debris, or feces. By applying these uses, low operating noise and reliable venting of the pump chamber for sewage and / or wastewater submersible pumps can be ensured. Furthermore, this rotary pump can also be used in heating systems with radiators, heater systems, underfloor heating systems, ceiling cooling systems, water circulation systems in drinking water facilities, or drinking water systems with charging systems and storage tanks, where the above list is not exhaustive and may include other types of systems not mentioned herein.
[0030] Furthermore, this objective is achieved by a lifting device comprising a collection container and a rotary pump as described above, wherein the suction opening of the rotary pump faces the interior of the collection container. In principle, it is possible for the collection container of the lifting device to have an opening designed corresponding to the pump housing. The opening of the collection container can be closed by applying the rotary pump to the opening, wherein the suction opening of the rotary pump advantageously faces the interior of the collection container.
[0031] Alternatively, at least a portion of the container wall of the collection container can be formed by a pump housing with a suction opening. In this case, it can be proposed that the container wall be formed such that it constitutes the bottom portion of at least two-piece pump housings. The opening in the container wall is the suction opening of the rotary pump. The exhaust passage preferably leads from the exhaust opening to the outside of the rotary pump, which is also preferably formed by the container wall.
[0032] According to a preferred embodiment of the invention, the drive motor of the rotary pump is at least partially arranged outside the collection container. This arrangement has proven particularly advantageous for the maintenance of the lifting device. Preferably, the drive motor is completely positioned outside the collection container.
[0033] Further implementations and advantages of using rotary pumps and / or lifting devices will be apparent to those skilled in the art in a manner similar to that described above for rotary pumps. Attached Figure Description
[0034] The invention will now be explained in detail with reference to the accompanying drawings and preferred embodiments.
[0035] In the attached diagram:
[0036] Figure 1 A schematic diagram of a rotary pump in a lifting device according to a preferred embodiment of the present invention is shown, and
[0037] Figure 2 A further schematic diagram of a rotary pump in a lifting device according to a preferred embodiment of the present invention is shown. Detailed Implementation
[0038] Figure 1 and Figure 2 A schematic cross-sectional view of a rotary pump 10 in a lifting device 12 according to a preferred embodiment of the present invention is shown. This rotary pump can be used as a sewage and / or wastewater submersible pump.
[0039] The rotary pump 10 has a pump housing 16 forming a pump chamber 14. An impeller 18 is arranged inside the pump chamber 14. The impeller 18 is connected to a drive motor 24 of the rotary pump 10 via a motor shaft 22 extending in the axial direction. The pump housing 16 has a suction opening 26 concentric with the axis of the motor shaft 22, through which fluid flows into the pump chamber 14. By obtaining the rotational motion of the impeller 18, fluid is delivered to a pressure pipe 28 (shown schematically only). The suction opening 26 of the rotary pump 10 is located at the lowest point of the pump housing 16, and the axial direction of the motor shaft 22 corresponds to the vertical direction.
[0040] Furthermore, the pump housing 16 of the rotary pump 10 has an exhaust opening relative to the suction opening 26 located behind the impeller 18, and this exhaust opening is designed in the form of a check valve 52. Figure 1 In the rotary pump 10, the check valve 52 is located at the highest point of the pump chamber 14 and extends beyond the height of the impeller 18, which is fastened to the motor shaft 18. The check valve 52 is designed to close and open due to fluid flow to allow air to escape from the pump chamber 14, as described further below.
[0041] The lifting device 12 also includes a collection container 36, which can be connected to the rotary pump 10. To connect the rotary pump 10 to the collection container 36, the container wall 38 of the collection container 36 has an opening corresponding to the pump housing 16. In this preferred embodiment, the rotary pump 10 and the collection container 36 are connected such that the suction opening 26 of the rotary pump 10 faces the interior of the collection container 36. Specifically, a portion of the container wall 38 is formed from the pump housing 16 having the suction opening 26. The container wall 38 is shaped to form at least two parts of the bottom portion of the pump housing 16.
[0042] The previously mentioned check valve 52 is positioned behind the impeller 18 relative to the suction opening 26, within the annular space 20 defined by the impeller 18 and the pump housing 16, through which the motor shaft 22 is guided centrally. Specifically, the check valve 52, acting as a check flap, is made of a floatable rubbery material, particularly a fluorinated elastomer or rubber, and is fastened to the pump housing 16 on its underside relative to the impeller 18. Thus, in the event of an increase in fluid in the pump chamber 14, the check valve 52 is released from its position due to the fluid and / or the air pressure in the pump chamber 14. Figure 1 The opening position shown in the diagram pivots to Figure 2 The closed position is shown in the diagram. Alternatively, check valve 52 can be designed as a flap valve and / or a ball valve.
[0043] Connected to check valve 52 is exhaust passage 50, which is horizontally guided away from annular space 20 and defined by automatic valve 32 opposite check valve 52. Automatic valve 32 allows air to escape from pump chamber 14 while preventing air from being introduced into pump chamber 14. Automatic valve 32 is designed as a duckbill valve or a hose-like valve with two tabs that press against each other during backflow and / or press against each other when flowing back into pump chamber 14.
[0044] The check valve 52 has an upper circular portion whose diameter corresponds to the diameter of the exhaust passage 50. The upper circular portion is fastened to a thicker lower portion via a thinner intermediate portion, with these three portions implemented as a single piece. This lower portion is fastened to the pump housing, for example by screwing or bonding. Because the intermediate portion has a smaller thickness relative to the two other portions, it allows this tab-shaped check valve 52 to pivot between an open and closed position. Under no-load conditions, the check valve 52 is in the open position. However, if the air pressure and / or fluid in the pump chamber 14 exceeds a threshold (especially in the annular space 20), the air pressure and / or fluid causes the check valve 52 to close.
[0045] The described embodiments are merely examples, and these examples can be modified and / or supplemented in various ways within the scope of the claims. Each feature used to illustrate a particular embodiment can be used independently or in combination with other features in any other embodiment. Each feature used to illustrate an embodiment of a certain category can also be applied accordingly to embodiments of another category.
[0046] List of reference numerals
[0047] Rotary pump 10;
[0048] Lifting device 12;
[0049] Pump chamber 14;
[0050] Pump housing 16;
[0051] Impeller 18;
[0052] Annular space 20;
[0053] Motor shaft 22;
[0054] Drive motor 24;
[0055] Suction opening 26;
[0056] Pressure takeover 28;
[0057] Valve 32;
[0058] Collection container 36;
[0059] container wall 38;
[0060] Exhaust passage 50;
[0061] Check valve 52.
Claims
1. A rotary pump (10) for conveying fluid, said rotary pump having: Pump casing (16) forms the pump chamber (14); An impeller (18) is disposed in the pump chamber (14) for conveying the fluid; A suction opening (26) provided in the pump housing (16) is used to draw the fluid into the pump chamber (14) through the impeller (18); and A check valve (52) is disposed in the pump housing (16) behind the impeller (18) relative to the suction opening (26). The check valve closes due to the fluid entering the pump chamber and / or due to the dominant air pressure in the pump chamber (14), and when open, allows air to escape from the pump chamber (14). The check valve (52) is made of buoyancy material and is fastened to the pump housing (16) at its end facing the impeller.
2. The rotary pump (10) according to claim 1, wherein the check valve (52) is designed as a check flap, flap valve and / or ball valve.
3. The rotary pump (10) according to claim 1, wherein the check valve (52) is designed to close in the event of an increase in the fluid in the pump chamber (14).
4. The rotary pump (10) according to any one of claims 1 to 3, wherein the check valve (52) is made of plastic or elastomer.
5. The rotary pump (10) according to claim 4, wherein the elastomer is a fluorinated elastomer.
6. The rotary pump (10) according to claim 4, wherein the elastomer is rubber.
7. The rotary pump (10) according to any one of claims 1 to 3, wherein an annular space (20) defined by the impeller (18) and the pump housing (16) is formed behind the impeller (18) relative to the suction opening (26), and the check valve (52) is provided in the annular space.
8. The rotary pump (10) according to any one of claims 1 to 3, the rotary pump having: an exhaust passage (50) connected to the check valve (52) and located away from the pump chamber (14) and an automatic valve (32) disposed at the exhaust passage (50), the automatic valve allowing air to escape from the pump chamber (14) and preventing air from entering the pump chamber (14).
9. The rotary pump (10) according to claim 8, wherein the automatic valve (32) is designed as a self-closing flap valve, a duckbill valve and / or a hose-like valve with two protrusions that come into contact with each other during backflow and / or during backflow into the pump chamber (14).
10. The use of a rotary pump (10) according to any one of claims 1 to 9 as a sewage and / or wastewater submersible pump.
11. A lifting device (12) comprising a collection container (36) and a rotary pump (10) according to any one of claims 1 to 8, wherein the suction opening (26) of the rotary pump (10) faces the interior of the collection container (36).
12. The lifting device (12) according to claim 11, wherein at least a portion of the container wall (38) of the collection container (36) is formed by a pump housing (16) having the suction opening (26).
13. The lifting device (12) according to claim 11 or 12, wherein the drive motor (24) of the rotary pump (10) is arranged at least partially outside the collection container (36).