Centrifugal pump comprising an impeller

Abstract

The invention relates to a centrifugal pump comprising at least one impeller (1) for delivering a fluid, wherein the impeller (1) has a support plate (2) with blades (3) which project into a first space (5). Each blade (3) has a blade leading edge (7), a blade trailing edge (10), a blade suction side (11), and a blade pressure side (12), and at least one blade (3) has at least one channel (13) through which a fluid flow flows through at least one opening (14) in the blade (3).

Description

[0001] 10524F

[0002] KSB SE & Co. KGaA 67227 Frankenthal

[0003] Description

[0004] Centrifugal pump with one impeller

[0005] The invention relates to a centrifugal pump with at least one impeller for pumping a fluid, wherein the impeller has a support disk with blades projecting into a first space, wherein each blade has a blade leading edge, a blade exit edge, a blade suction side and a blade pressure side.

[0006] An impeller is a rotating component of a turbomachine, equipped with blades. Mechanical power is converted into hydraulic flow rate at the blades.

[0007] Multistage pumps are characterized by the arrangement of several impellers in series, through which the pumped fluid flows sequentially. The delivery head of a single-stage centrifugal pump is primarily determined by the impeller design and the peripheral speed. If the rotational speed cannot be increased further, and increasing the impeller diameter leads to very low specific speeds and thus uneconomical efficiencies, connecting several stages in series allows for an economical increase in the delivery head. With otherwise identical dimensions and rotational speeds, the flow rate of such a multistage pump remains unchanged, while the power consumption and delivery head are proportional to the number of stages.

[0008] Each stage comprises an impeller, a guide vane, and a return blade, all housed within a stage casing. Regardless of the number of stages, an inlet casing with a radial or axial inlet nozzle is positioned upstream of the first stage, and the final stage is located in the pressure casing, which contains the relief device and a shaft seal. Only the common pump shaft, connecting bolts, and base plate need to be adapted to the specific number of stages.

[0009] DE 10 2015 213 451 A1 describes a centrifugal pump with an impeller having at least one blade, and a method for designing the profile of a blade. The blade has a profile resulting from the superposition of a symmetrical profile with at least one additional profile and a skeleton line whose blade entry angle is less than 0°.

[0010] DE 10 2022 001 479 A1 relates to a centrifugal pump arrangement for conveying a medium with a shaft seal, which has a system comprising a venting arrangement and a cooler, wherein a medium circulates in the system.

[0011] DE 10 2020 133 327 B4 discloses a pump arrangement with a jacket housing, an insert arranged at least partially in the jacket housing, wherein the insert comprises a shaft rotatably arranged about a rotary axis by a drive, and at least two pressure stages, each with a pressure stage housing, an impeller arranged on the shaft surrounded by the pressure stage housing in each pressure stage, and a seal separating a first pressure chamber from a second pressure chamber.

[0012] A conventional centrifugal pump impeller is typically designed and optimized for a specific operating point or a relatively narrow operating range with a fixed geometry. Outside this range, flow separation can occur at the impeller, particularly at the blade leading edges. This results in efficiency losses, a drop in delivery head, and / or an increased tendency to cavitation. 3 10524F

[0013] The object of the invention is to provide a centrifugal pump that exhibits the lowest possible tendency to flow separation. The centrifugal pump should have a high efficiency. Furthermore, the centrifugal pump should not be highly susceptible to cavitation. The centrifugal pump should be simple and cost-effective to implement.

[0014] This problem is solved according to the invention by a centrifugal pump with at least one impeller for pumping a fluid according to the features of claim 1. Preferred embodiments can be found in the dependent claims, the subclaims, the description and the drawings.

[0015] According to the invention, at least one blade has at least one channel through which a fluid flow passes through at least one opening in the blade.

[0016] For example, to reduce flow separation, the fluid flow is directed through the opening. The fluid flow can be injected or extracted.

[0017] In a preferred embodiment of the invention, each blade has at least one channel through which a fluid flow passes through at least one opening in the blade.

[0018] The channel is preferably designed as a duct-like conduit. The channel can have a round, rectangular, square, trapezoidal, polygonal, cloverleaf-shaped, or complex cross-section. Such cross-sectional shapes can ideally be manufactured additively, e.g., using metallic 3D printing processes, since conventional tools, such as drills, can only produce round cross-sections. In one embodiment of the invention, the cross-sectional shapes can vary along the length of the channel.

[0019] In one embodiment of the invention, the channel is designed as a curved channel. The channel is shaped in such a way as to enable a low-loss and efficient flow of the fluid stream. 4 10524F

[0020] After exiting the impeller, the fluid flows into a second chamber, with the first chamber being connected to the second chamber, for example, via the channel.

[0021] The first room, for example, is the pump room, which has a lower pressure.

[0022] In one variant of the invention, the space extends from the suction side of the pump to the impeller channel, including the area of ​​the openings.

[0023] The first space extends from the suction side of the pump to just before the entrance to the impeller channel, for example to the leading edge of the impeller inside the wheel.

[0024] Thus, the first space is located within the impeller, between the support and cover discs, in particular from the suction mouth to the leading edge of the blade channel.

[0025] The second space includes, for example, the wheel side space and thus the space of the pump, which has a higher fluid pressure than the first space.

[0026] In an alternative version of the invention, the first space is connected to a fluid reservoir via the channel, whereby a fluid flow can flow out of or into the fluid reservoir through an opening in the respective blade.

[0027] For example, the second space could also contain a pressure vessel.

[0028] In particular, the design of the channel through which a fluid flow passes through at least one opening in the respective blade to reduce flow separation differs considerably from previously known axial thrust compensation bores. The axial thrust compensation bore does not extend to the blade channel and, due to the gap design between the housing and the impeller 5 10524F, exhibits a completely different pressure differential level, generally significantly lower compared to the channel according to the invention.

[0029] For example, at least one channel extends from the support disc to the blades of the impeller.

[0030] In one variant of the invention, the support disc comprises a system of channels, wherein at least one channel extends into each blade, opening into an opening on the blade.

[0031] For example, the support disc has a ring-shaped channel from which branches supply at least one channel for each blade with a fluid flow. In this way, a channel ring in the support disc feeds a channel arrangement in the blades with a fluid flow, which flows through an opening in each blade to modify the velocity profile in the boundary layer region in order to reduce flow separation.

[0032] In one variant, the support disc has a central system of channels, while in the blades a secondary or distribution system of channels is arranged by means of branches.

[0033] The system of channels leads into at least one opening per bucket.

[0034] For example, at least one opening per blade in the form of a slot can cover as wide an area of ​​the blade channel as possible.

[0035] In another variant, several openings can be arranged per blade, so that as large an area as possible of the blade channel height can be overflowed and influenced by a fluid flow.

[0036] In one embodiment of the invention, the at least one opening has an angle in the direction of flow, wherein the angle is greater than 0° and less than 90°. The 6 10524F

[0037] The opening thus protrudes in the direction of the flow, so that the fluid flow can be efficiently injected and flows along the blade surface.

[0038] In another variant, at least one opening is angled against the flow direction, so that the opening protrudes against the flow. This makes the orientation of the opening ideal for suction. For example, the angle between the blade and the opening is between 90° and 180°.

[0039] For example, the opening of at least one channel is arranged at an angle to the blade, where the angle is greater than 0° and less than 90°. This angle creates a fluid flow that flows directly along the blade, thus altering the velocity profile in the boundary layer region, thereby at least reducing and ideally completely preventing flow separation.

[0040] In one variant of the invention, the angle of the channel to the blade is more than 10° and less than 30°.

[0041] In a flowing fluid, the boundary layer is the region where, along solid walls and in close proximity to the wall, the flow velocity increases from the value of the wall velocity to the value of the surrounding flow, unaffected by wall friction. The boundary layer thickness is defined, for example, as the distance from the wall at which the flow velocity reaches approximately 99% of the value of the surrounding flow. Both laminar and turbulent flow can occur within the boundary layer. Even a turbulent boundary layer always has a laminar region, also called a viscous sublayer, in close proximity to the wall.

[0042] The boundary layer may detach from the wall. Behind the separation point, a separation zone forms, which is heavily permeated by vortices. The flow velocities in this zone are usually disordered in magnitude and direction, and a backflow sometimes develops. The reason for flow separation is generally an excessively slow flow velocity in the boundary layer, i.e., a boundary layer with insufficient kinetic energy. When the outer flow decelerates, this is usually accompanied by an increase in pressure in the main flow direction. Flow separation occurs when the slow-moving fluid of the boundary layer no longer has enough kinetic energy to flow against the increasing pressure. The deceleration of the outer flow occurs primarily at sharp deflections of the main flow on blades. Separation is associated with turbulence and resulting additional flow losses.Furthermore, the separation zone of the main flow reduces the effective flow cross-section through the blade channel.

[0043] The inventive design of a centrifugal pump with at least one impeller, in which each blade has at least one channel through which a fluid flow passes through at least one opening in the respective blade to reduce flow separation, leads to an advantageous energization of the boundary layer (increase in the kinetic energy of the fluid in the boundary layer). The boundary layer can be energized, for example, either by injecting an additional fast fluid flow or by drawing off existing slow flow regions. This energization prevents flow separation, efficiency losses, and head drops, and reduces the probability of cavitation.

[0044] Flow separations present obstacles that can be blown away or suctioned off, for example, by injecting a fluid stream.

[0045] The special design of the impeller with an integrated system of channels from the wheel side space via the support disc to the blade leading edge, in combination with a specially designed outlet angle of the channel opening with simultaneously optimized opening shape, creates a fluid flow that advantageously modifies the velocity profile in the boundary layer area of ​​the impeller blade, so that flow separation can be reduced or even completely prevented.

[0046] For example, the opening is circular or elliptical or square or rectangular or polygonal, so that the fluid flow flows as directly as possible along 8 10524F of the blade and can also influence as large a blade area as possible with an additional fluid flow.

[0047] In one variant of the invention, at least one opening of the channel is arranged on the blade pressure side.

[0048] The pressure side of an impeller blade is the side where the higher local pressure exists. During operation of the centrifugal pump, the impeller, which is equipped with several blades, rotates. The blades accelerate the fluid flowing through the pump circumferentially and outwards, thereby increasing the fluid's energy content. The pressure side of the blade is the side that displaces the fluid in the direction of rotation.

[0049] For example, at least one opening of the channel is located on the suction side of the blade.

[0050] The suction side of an impeller blade is located on the opposite side from the pressure side. The suction side is the side of an impeller blade where the pressure is lower.

[0051] The leading edge of the impeller blade is the edge that extends furthest towards the impeller suction inlet. The fluid first encounters the leading edge of the blade as it flows through the impeller.

[0052] The blade trailing edge is the end piece of the blade of an impeller and is located at the outer edge of the impeller. Starting from the blade leading edge, the blade extends across the suction side and the pressure side to the blade trailing edge.

[0053] In one embodiment of the invention, at least one opening is arranged in a region, wherein the region is less than 30% of the distance from the blade leading edge to the blade trailing edge. This allows the fluid flow to influence the boundary layer along the blade from the beginning of the blade, thereby reducing flow separation over a large area of ​​the blade.

[0054] In one variant of the invention, the support disc has at least one support disc opening in an entry area in front of the blade leading edge, through which a fluid flow passes to reduce flow separation.

[0055] The inlet area is the region within the impeller of a centrifugal pump that extends immediately in front of the leading edge of the impeller blade and thus in front of the impeller channel. The inlet area is bounded by the support disc and the cover disc.

[0056] Unlike an opening in a blade, a support disc opening is located within the support disc. The support disc opening points towards the blade channel, allowing the fluid flow within it to influence the flow on the blades and reduce flow separation. For example, the support disc opening can create a fluid flow that extends over blade areas that would be more difficult to access through an opening in the blade itself.

[0057] In one embodiment of the invention, the impeller has a cover plate and is thus designed as a closed impeller. The invention therefore encompasses both open and closed impellers.

[0058] The cover plate of a centrifugal pump impeller is a component located at the edge of the impeller that connects the blades. It forms the outer boundary of the impeller and can serve to direct and control the flow within the impeller.

[0059] In one variant of the invention, the channel connecting the second chamber to the first chamber can also be integrated into the cover plate. 10 10524F

[0060] In one variant of the invention, the cover plate has at least one cover plate opening in an inlet area in front of the blade leading edge, through which a fluid flow passes to reduce flow separation.

[0061] Unlike the opening in a blade, the shroud opening is located in the shroud itself. The shroud opening points towards the blade channel, so that the fluid flowing through it can influence the blades to reduce flow separation.

[0062] For example, the canal has at least one bend.

[0063] The arc of a channel includes at least one curved section, which differs from the design of a bore in the form of a straight channel due to the curvature.

[0064] For example, the channel has a curve from the inlet opening in the second chamber to the outlet opening in the first chamber. The design of the curve ensures a low-loss flow of the fluid.

[0065] In one variant of the invention, the channel has at least one branch.

[0066] The branching indicates a section of the channel where the channel splits or branches to direct the fluid flow to different or multiple openings.

[0067] For example, the support disc has a system of channels from which at least one channel per blade branches off, and the at least one channel per blade can branch into several openings.

[0068] In one embodiment of the invention, the opening of the channel has a diameter which is more than 20% and less than 50% of the local blade thickness. The shape and size of the opening allow for a large 11 10524F

[0069] The area of ​​the blade is influenced by the fluid flow in addition to changes in the velocity profile in the boundary layer region.

[0070] In one variant of the invention, the opening is designed as a slot, wherein the width of the slot is more than 50% and less than 90% of the local blade width or blade channel height.

[0071] For example, the channel is generatively integrated into the blade and the support disc and / or the cover disc.

[0072] In one embodiment of the invention, the channel, in particular the system of channels in the support disc and / or in the cover disc and in the blades, is produced by a method in which the channel or channels in the impeller of the centrifugal pump are generated by selectively applying energetic radiation to layered powder layers.

[0073] Selective laser melting (SLM) is an additive manufacturing process used to produce the channel in the impeller from metal powder. It is a form of 3D printing that uses a high-power laser to selectively melt the powder and build the impeller with integrated channels layer by layer.

[0074] The impeller, with at least one integrated channel, is built up layer by layer by applying a thin layer of powder to a build platform. The laser beam is then directed at the selected areas, where it melts the metal powder and fuses it into a solid layer. A new layer is then applied, and the process is repeated until the impeller, consisting of a support disc and optionally a cover disc and blades, is complete.

[0075] Preferably, a high-power laser, typically a fiber laser or a CO2 laser, is used. The laser beam is precisely controlled to fuse the metal powder. The laser parameters, such as power, intensity, and feed rate, are set according to the requirements of the process and the selected material, particularly a metallic material. For example, the laser parameters can also be adjusted partially to achieve defined and desired microstructures.

[0076] After additive manufacturing, the impeller with at least one integrated channel may require further processing.

[0077] In an alternative version of the invention, the channel comprises at least one switch.

[0078] For example, the channel has a fluidic switch upstream of the opening.

[0079] A fluidic switch is an element integrated into a duct that controls or regulates the flow of a fluid based on specific conditions or signals. Unlike mechanical or electrical switches, which respond to mechanical or electrical signals, a fluidic switch uses the flow properties of a fluid, such as its momentum (inertial effect) or pressure, to control the flow.

[0080] Fluidic switches, analogous to electronic components, can perform Boolean logic operations between multiple fluid flows, as well as control fluid flows by other fluid flows (analogous to an electronic transistor) or create a single possible flow direction (analogous to an electronic diode).

[0081] A fluidic switch can, for example, control the flow of fluid in a pipe system depending on pressure, temperature, fluid level, or other parameters. It can be designed to either open or close the flow, or to switch between different flow rates, depending on the system requirements. A key feature is that a fluidic switch can function without any moving mechanical parts, operating solely through the clever combination of geometry and the inertial effects of the flow.

[0082] This specially designed fluidic switch can create a fluid flow through the channel when, for example, flow conditions prevail that promote flow separation at the impeller blades, such as in the partial-load or overload operating range of the centrifugal pump. This fluid flow, which flows through the channel to the opening and then modifies the velocity profile in the boundary layer region of the impeller blade, can thus reduce flow separation in unfavorable operating ranges of the centrifugal pump.

[0083] In one embodiment of the invention, the fluidic switch provides an inflow from a reservoir or an inflow into this reservoir, so that the fluid flow flows from or into this reservoir to reduce flow separation and is subject to an externally defined pressure.

[0084] For example, the fluidic switch can be arranged in the channel, with the channel conveying a control pressure from the wheel side chamber to the fluidic switch. This channel section is then designed as a control pressure channel. At a corresponding control pressure, the fluidic switch can now enable flow from another channel section, whereby this channel section then opens a connection to an external reservoir with at least one opening, for example in the blade or in the support or cover plate, thus generating a fluid flow to reduce flow separation.

[0085] For example, the fluidic switch can also implement a channel flow for extraction at the opening of the shovel when the appropriate control pressure is applied.

[0086] In general, the invention encompasses the use of all known switching technologies, in particular electronic and electromechanical ones. The switching technology can be designed to be active or passive and may optionally interact with an external control system. 14 10524F

[0087] In one design variant, at least one switch can also be arranged in the channel in front of the cover and / or support disc opening.

[0088] In a further embodiment of the invention, a channel system for connecting the first and second spaces extends both over the cover plate and over the support plate into the blades to the opening of the channel in order to realize a fluid flow in the boundary layer region which can prevent flow separation.

[0089] The invention encompasses both single-stage and multi-stage centrifugal pumps.

[0090] According to the invention, a centrifugal pump with an impeller in whose blades integrated channels are arranged starting from the support disc and / or cover disc is used to broaden the operating point range of the centrifugal pump.

[0091] The boundary layer control achieved through a channel integrated into the impeller with at least one opening on the blade pressure or suction side incorporates the concept of boundary layer injection. This involves the targeted introduction of additional kinetic energy and momentum into the boundary layers at the blade leading edges. This shifts, for example, the starting points of boundary layer separation on the blade suction or pressure side towards lower or higher flow rates, respectively. As a result, the pump hydraulics can advantageously be operated over a wider operating range with higher efficiency, higher delivery head, and reduced cavitation tendency.

[0092] This results in a thinner boundary layer in areas prone to flow separation, leading to higher kinetic energy and momentum in the flow direction in these areas, which reduces the tendency for flow separation. 15 10524F

[0093] Additionally, the tendency to cavitation can be reduced by avoiding and / or reducing the size of separation zones, where pressure is usually lower than in their immediate vicinity.

[0094] The design of the integrated channels can be conceived using hydraulic and structural mechanics principles and implemented additively. 3D printing offers maximum flexibility in shaping the channels. This allows for the application of fluidic logic principles to achieve adaptive or highly variable hydraulic properties. Consequently, boundary layer control can be managed without moving components.

[0095] The fluid for the injection system is tapped, for example, in the wheel lateral space behind the support disc. Here, the static pressure is higher than at the blade leading edges. Due to the driving pressure difference, the fluid flows through a custom-optimized, curved, and branching channel inside the support disc and impeller blades to the openings at the blade leading edges.

[0096] The inlet to the channel in the wheel lateral area can be designed as a single opening or, for example, as a circumferential collecting groove. The openings at the leading edges of the blades can be designed at an optimally angled position or approximately tangential to the blade surfaces.

[0097] Further features and advantages of the invention will become apparent from the description of exemplary embodiments with reference to the drawings and from the drawings themselves.

[0098] This shows:

[0099] Fig. 1 shows a sectional view through an impeller of a centrifugal pump,

[0100] Fig. 2 shows a sectional view of an impeller with a slotted opening, 16 10524F

[0101] Fig. 3 shows a sectional view of an impeller with a channel in the impeller shaft,

[0102] Fig. 4 shows a sectional view of an impeller with a fluidic switch,

[0103] Fig. 5 shows a sectional view of an impeller with openings on the support and cover plates.

[0104] Fig. 6 shows a sectional view in a plane perpendicular to the axis of rotation through the blades of an impeller.

[0105] Fig. 7 shows a detailed view of a blade with an opening for fluid injection.

[0106] Fig. 8 shows another detailed view of a shovel with an opening for fluid extraction.

[0107] Fig. 1 shows a sectional view through an impeller 1 of a centrifugal pump. The impeller 1 has a support disk 2, a cover disk 4, and blades 3, which together define the first chamber 5. The first chamber 5 thus extends from the suction inlet 6 between the support disk 2 and the cover disk 4 to the leading edge 7 of the blades.

[0108] The fluid pumped by the centrifugal pump flows through the first chamber 5, through the impeller channel 8, into a second chamber 9 at a higher pressure, which is formed by the centrifugal pump housing (not shown) between the impeller 1 and the housing. In the illustrated embodiment, the second chamber 9 comprises the impeller side chamber.

[0109] Each blade 3 has a leading edge 7, a trailing edge 10, a suction side 11, and a pressure side 12. Each blade 3 has at least one channel 13 which, in this embodiment, connects the second chamber 9 with the first chamber 5. The channel 13 is additively integrated into the blade 3. A fluid flow passes from the second chamber 9 into the first chamber 5 through at least one opening 14 in the blade 3 to modify the velocity profile in the boundary layer region and reduce flow separation.

[0110] The channel 13 extends from the support disc 2 into the blade 3. In the illustrated embodiment, the channel 13 has at least one branch 15 and one bend 16.

[0111] The opening 14 has a diameter which, in the illustrated embodiment, is approximately 10-15% of the local blade channel height 17.

[0112] Fig. 2 shows a sectional view of an impeller 1 with a slot-shaped opening 14. The representation essentially corresponds to the representation in Fig. 1. The slot-shaped opening 14 has a width of approximately 80% of the local blade channel height 17.

[0113] In the case of boundary layer extraction through the slot-shaped opening 14, it may be advantageous to design the downstream edge of the slot-shaped opening 14 to be raised compared to the upstream edge in order to achieve efficient extraction of the boundary layer.

[0114] Figure 3 shows a sectional view of an impeller 1 with the channel 13, which passes through a shaft 20. The channel 13 connects the fluid reservoir 19 (not shown) through the shaft 20 to the opening 14. A fluid flow passes through the channel 13 to modify the velocity profile in the boundary layer region in order to reduce flow separation in the blade channel 8.

[0115] Figure 4 shows a sectional view of an impeller 1 with a fluidic switch 18. In the illustrated embodiment, the fluidic switch 18 is arranged such that the control pressure from the impeller side chamber 9 is applied to the fluidic switch 18 via a control channel 27. At the appropriate control pressure, the fluidic switch 18 initiates a flow through the channel 13 from a fluid reservoir 19 (not shown) to the opening 14. The channel 13 connects the fluid reservoir 19 (not shown) to the fluidic switch 18 via the shaft 20, thus allowing a fluid flow to modify the velocity profile in the boundary layer region in order to reduce flow separation.

[0116] Fig. 5 shows a sectional view of an impeller 1. The cover plate 4 has at least one cover plate opening 22 in an inlet area 21 in front of the blade leading edge 7, and the support plate 2 has at least one support plate opening 23 in an inlet area 21 in front of the blade leading edge 7, through which a fluid flow flows to reduce flow separation by influencing the flow towards the blades.

[0117] Furthermore, the impeller 1 also has an axial thrust relief bore 24. Due to the gap 25, the axial thrust relief bore 24 for connecting the first chamber 5 with the second chamber 9 has a much lower pressure differential than the pressure differential between chamber 5 and chamber 9 upstream of the gap 25 and is also not suitable for generating a fluid flow to reduce flow separation in the blade channel 8.

[0118] Figure 6 shows a sectional view through the blades 3 of the impeller 1. The opening 14 is located on the blade suction side 11.

[0119] The opening 14 is arranged in a region 26. In the illustrated embodiment, the region 26 is located approximately 10% of the distance between the blade leading edge 7 and the blade exit edge 10 from the blade leading edge 7.

[0120] Figures 7 and 8 each show a detailed view of a blade 3 with an opening 14. In Figure 7, the opening 14 is arranged at an angle α to the blade 3, where the angle α in the illustrated embodiment is approximately 30° and is suitable for injecting a fluid flow to reduce flow separation.

[0121] The opening 14 in Fig. 8 is arranged at an angle α of approximately 110° to the blade 3 and is suitable for drawing off a fluid flow to reduce flow separation. 19 10524F

[0122] Reference symbol list

[0123] 1 impeller 18 fluidic switch

[0124] 2 Support disc 19 Fluid reservoir

[0125] 3 shovel 20 shaft

[0126] 4 Cover plate 21 Entrance area

[0127] 5 First room 22 Cover plate opening

[0128] 6 Suction nozzle 23 Support disc opening

[0129] 7 Blade leading edge 24 Axial shear relief hole

[0130] 8 paddle channel 25 gap

[0131] 9 Second Room 26 Area

[0132] 10 Blade exit edge 27 Control channel

[0133] 11. Suction side of the bucket at an angle

[0134] 12. Bucket pressure side

[0135] Channel 13

[0136] 14 Opening

[0137] 15 branching

[0138] 16 sheets

[0139] 17 Scoop channel height

Claims

20 10524F Patent claims Centrifugal pump with one impeller 1. Centrifugal pump with at least one impeller (1) for pumping a fluid, wherein the impeller (1 ) has a support disk (2) with blades (3) projecting into a first space (5), wherein each blade (3) has a blade leading edge (7), a blade exit edge (10), a blade suction side (11 ) and a blade pressure side (12), characterized in that at least one blade (3) has at least one channel (13) through which a fluid flow passes through at least one opening (14) in the blade (3).

2. Centrifugal pump according to claim 1, characterized in that the fluid flow flows through the opening (14) to reduce flow separation.

3. Centrifugal pump according to claim 1 or 2, characterized in that the fluid flows into a second chamber (9) after exiting the impeller (1 ), wherein the first chamber (5) is connected to the second chamber (9) via the channel (13).

4. Centrifugal pump according to one of claims 1 to 3, characterized in that the first chamber (5) is connected to a fluid reservoir (19) via the channel (13).

5. Centrifugal pump according to one of claims 1 to 4, characterized in that at least one switch (18), preferably a fluidic switch, is located in front of the opening (14). 21 10524F Switches are arranged.

6. Centrifugal pump according to one of claims 1 to 5, characterized in that the support disk (2) has at least one support disk opening (23) in an inlet area (21) in front of the blade leading edge (7), through which a fluid flow flows to reduce flow separation.

7. Centrifugal pump according to one of claims 1 to 6, characterized in that the impeller (1 ) has a cover plate (4).

8. Centrifugal pump according to claim 7, characterized in that the cover plate (4) has at least one cover plate opening (22) in an inlet area (21) in front of the blade leading edge (7), through which a fluid flow flows to reduce flow separation.

9. Centrifugal pump according to one of claims 1 to 8, characterized in that at least one opening (14) projects at an angle (a) in the direction of flow.

10. Centrifugal pump according to one of claims 1 to 8, characterized in that at least one opening (14) projects at an angle (a) against the direction of flow.

11. Centrifugal pump according to one of claims 1 to 10, characterized in that the opening (14) is circular or elliptical or square or rectangular or polygonal.

12. Centrifugal pump according to one of claims 1 to 11, characterized in that at least one opening (14) is arranged on the impeller pressure side (12).

13. Centrifugal pump according to one of claims 1 to 12, characterized in that at least one opening is arranged on the impeller suction side (11 ). 22 10524F 14. Centrifugal pump according to one of claims 1 to 13, characterized in that at least one opening (14) is arranged in a region (26), wherein the region (26) is less than 30% of the distance from the blade leading edge (7) to the blade exit edge (10) from the blade leading edge (7).

15. Centrifugal pump according to one of claims 1 to 14, characterized in that the channel (13) is additively integrated into the blade (3).

16. Centrifugal pump according to one of claims 1 to 15, characterized in that the channel (13) has at least one bend (16).

17. Centrifugal pump according to one of claims 1 to 16, characterized in that the channel (13) has at least one branch (15).

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