EP1876359B1 - Pond pump - Google Patents

Abstract

The pump has a rotor (2) rotatable around a rotation axis in a pump housing, where the housing has a suction inlet arranged axial to the rotor, a pressure outlet for the water and a housing section provided between the inlet and the outlet. The rotor has a radially arranged circular plate (22) with wings (21), where a side of the rotor is attached to the section. Flow channels (23) are formed between the wings, a circular plate and a reverse plate, where the flow channels have a cross section that is decreased from the radial inner side to an outer side in a flow direction.

Description

The invention relates to a pond pump with impeller rotating in a pump housing about an axis of rotation, wherein the pump housing has a suction inlet arranged axially to the impeller, a pressure outlet arranged radially to tangentially to the impeller for the water to be conveyed and a housing section between suction inlet and pressure outlet, wherein the impeller a radially arranged circular disc with wings arranged on one side and wherein the housing portion of the associated with the wings open side of the impeller assigned and formed as a flat mating plate and wherein between the wings, the circular disk and the mating disk flow channels are formed.

Such a pump is out of the US 5,713,719 , which is considered to be the closest prior art, known as a centrifugal or centrifugal pump with an open impeller. The impeller has impeller vanes. Between the pump impeller blades, a circular disk carrying the impeller blades and a housing portion, flow channels are formed. These flow channels increase in their cross section from the radial inside to the outside.

Furthermore, from the WO 94/03731 a centrifugal pump with a free-flow impeller, in which flow channels between complete pump blades, which extend from the axis of rotation of the impeller to the radial periphery, and short pump blades, which are arranged in the outer ring portion of the impeller, are formed. These flow channels also increase from the inside to the outside in their cross-section.

From the US 2004/0126228 A1 is a centrifugal pump with a special geometry of the spiral housing is known in which a closed impeller with first and second cover plate is provided with flow channels arranged therebetween.

Furthermore, centrifugal pumps are generally known in the art, which have a rotating impeller for the promotion of water. The pumps are usually immersed in the water to be pumped (submersible) used. Of course, a pipe for sucking the water to be pumped can be arranged on the suction side. For dry installation, the pump must be placed next to the pond below the water level. On the pressure side, the pumped water is conveyed via a pipeline, for example, to a pond filter, a fountain, an applied watercourse or the like.

Centrifugal pumps operate on a hydrodynamic delivery principle, wherein the water to be conveyed fed near the axis of rotation of the impeller, entrained by the rotating impeller with its wings arranged thereon and forced to a circular path. Due to the centrifugal force of the rotating water on the circular path, the water is forced radially outward. Accordingly arises near the axis of rotation of the water supply Negative pressure (suction side) and at the periphery of the impeller an overpressure (pressure side).

Centrifugal pumps are very reliable and can be used in electrically fully encapsulated design as submersible pumps, for example, for swimming ponds. Furthermore, with appropriate design of the impeller and associated pump housing water can be promoted with solids, without the blockages are to be feared. In this case, the impeller is designed as a so-called free-flow impeller, so that the permissible solids size can be, for example, 6 mm (ball passage). Thus restrict only on the suction side coarse filter elements with a corresponding mesh size, the flow rate.

However, free-flow impellers have a somewhat lower efficiency than pumps with a closed impeller due to flow short circuits and concomitant internal pressure compensation. Pumps with a closed impeller, however, are more susceptible to clogging, so that a correspondingly finer filter on the suction side is provided, which complicates according to the free inflow.

Since pond pumps have very long operating times, sometimes also work continuously during the day and at night, an improvement in efficiency while allowing a large grain size, for example up to 6 mm, is desirable for economical operation. The object of the invention is therefore to optimize a generic centrifugal pump accordingly.

This object is achieved with a centrifugal pump according to claim 1. Surprisingly, it has been found in experiments that a centrifugal pump with an open impeller has an improved efficiency when formed between the wings flow channels a cross section which decreases in the flow direction from the radial inside to the outside. Obviously, the cross-sectional constriction in the flow channels in the radial direction from the axis of rotation to the outside causes an increase in the centrifugal forces and thus in the hydrodynamic delivery pressure. The reduction in the flow channel cross section is preferably 15% to 40%, preferably 20% to 35%.

In the embodiment of the above-mentioned pond pump with an open impeller, a flow channel cross-section reduction can preferably be realized in that the counter-rotating plate in the form of a wide-open conical surface section is formed at an angle (α) between 5 ° and 20 ° to the radial plane aligned with the axis of rotation in the direction of the impeller ,

Alternatively or additionally, the flow channel cross-section reduction is achieved in that the circular disc of the impeller in the form of a wide-open cone sheath is formed at an angle (β) between 5 ° and 20 ° to the rotational axis aligned to the radial plane in the direction of the mating plate.

Further, the efficiency of the pond pump is increased when the measured axially to the rotational axis height of the blades of the impeller decreases from the radially inner side to the outer side, so that the open side of the impeller is arranged with a substantially uniform gap distance from the mating plate. If the gap dimension is less than or equal to 1 mm, preferably less than 0.5 mm, pressure losses due to short-circuit flows between the impeller and the counter-rotating plate are reliably avoided.

In order to avoid clogging by solids in the flow channels of the impeller, the height of the wings on the radial outer side is greater than or equal to the width of the flow channels.

If the flow channels formed between the wings have substantially the same width from the radial inside to the outside of the impeller, the efficiency of the pump is further improved. Presumably, this improvement in efficiency should result from a further reduction of turbulence and thus flow losses. In addition, blockages are avoided by this design. In particular, the width of the flow channels should be greater than or equal to the max. allowable grain size, for example, greater than or equal to 6 mm, be formed.

If the wings have a crescent-shaped cross-section in the radial direction to the axis of rotation, a hydrodynamically particularly effective flow channel geometry is formed between the crescent-shaped vanes. Due to the crescent-shaped cross section, the wings have a high intrinsic stability, so that the impeller has a long service life.

In terms of manufacturing technology, it is advantageous if the mating plate is an integral part of the pump housing. The pump housing and / or the impeller are preferably produced from acrylonitrile-butadiene-styrene (ABS), modified polyphenylene oxide (PPO, so-called "Noryl") and / or polyoxymethylene / polyacetal (POM). In particular, the pump housing with integrally molded mating plate made of dimensionally stable and inexpensive ABS plastic. The impeller can be made both from ABS plastic in sufficient dimensional stability and strength as a low-cost component or for particularly heavy loads of PPO or POM plastic.

For a good electrical efficiency with low energy consumption for the pond pump to drive the impeller an asynchronous motor with stainless steel can in a housing provided in which a sealed encased in stainless steel rotor is mounted, which forms a removable from the housing running unit with the impeller. For a high load capacity and long Service life of the pump, the running unit is rotatably mounted in a ceramic bearing in the housing.

Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings.

Fig. 1

eine erfindungsgemäße Pumpe in einer Schnittdarstellung durch eine Axialebene und

Fig. 2

das in Figur 1 dargestellte Laufrad in Draufsicht.

It shows:

Fig. 1

a pump according to the invention in a sectional view through an axial plane and

Fig. 2

this in FIG. 1 illustrated impeller in plan view.

In Fig. 1 is a sectional view through an axial plane of a pond pump with a pump housing 1 and a rotating about a rotation axis X impeller 2 shown. A drive unit consisting of an electric motor arranged in a housing, preferably an asynchronous motor, can be attached to the side represented by arrow Y. About this in FIG. 1 not shown electromotive rotary drive, the impeller 2 is driven to rotate about the rotation axis X.

The pump housing 1 has a suction inlet 11, which is disposed opposite to the drive side Y coaxial with the axis of rotation X. At the suction inlet 11 a nozzle is formed, on which a suction line for supplying water to be conveyed can be placed. When using the pump as a submersible pump, the water can also be fed directly into the suction inlet 11. The water flow on the suction side is indicated by arrow Ws.

The pump housing 1, together with the drive unit Y, not shown, a housing of the rotary-driven impeller 2 to at Rotation of the impeller 2 to cause a hydrodynamic promotion of the water. In this case, the enclosure of the pump housing 1 around the periphery of the impeller 2 on an annular plenum 13, of which a substantially tangential to the impeller 2 arranged pressure outlet 14 in the direction of accelerated by the rotating impeller 2 on a circular path water from the pump housing in the direction of water drainage W _D is led out.

Between the axially arranged to the rotation axis X suction inlet 11 and the peripheral impeller 2 torus-shaped collecting chamber 13, a mating plate 12 is formed. The mating plate 12 forms an annular surface, which in the in FIG. 1 illustrated embodiment is designed as a wide open cone shell portion with an angle α of approximately 10 ° to the radial plane in the radial direction and the drive side Y directed inclined.

The impeller 2 has an aligned in a radial plane to the rotation axis X circular disc 22, are formed on the axially projecting in the direction of the suction side wings 21.

In FIG. 2 is the impeller 2 in a plan view from the direction of the suction side Ws (see Fig. 1 ). This in FIG. 2 illustrated impeller 2 has eight in its cross section in the radial axis X to the rotation axis sickle-shaped wings 21. Between the vanes 21, eight flow channels 23 are formed, which have a substantially constant width b of, for example, 6 mm between adjacent vanes 21, 21. For attachment of the impeller 2 on a rotor provided with a shaft of the drive unit Y, not shown, a central bore 24 is provided with integrally formed shaft 25 on the impeller 2.

As in FIG. 1 seen from the sectional view, the open side of the impeller 2 is located directly opposite to the mating plate 12 of the pump housing 1. Accordingly, the free projecting ends of the wings 21 of the angled α by the angle mating plate 12 adapted so that between the free upper edge of the wing 21 and the mating plate 12 results in a substantially uniform gap s of, for example, 0.5 mm.

During operation of the pond pump, the impeller 2 rotates about the axis of rotation X. The impeller 2 is driven by a drive unit Y, not shown. Due to the rotational movement of the impeller 2 with the wings 21 formed thereon, water present on the suction side Ws is sucked due to a negative pressure arising in the center of the impeller 2 and brought to a circular path via the flow channels 23. The centrifugal acceleration of the water in the flow channels 23 leads due to centrifugal force to a pressure increase and thus to the hydrodynamic delivery of the water to the pressure outlet 14 on the pressure side where the pump.

The small gap s of about 0.5 mm reliably prevents a flow short circuit, so that the pump works very effectively. Similarly, the formation of the flow channels 23 with a substantially constant width b equal to 6 mm allows a blockage-free promotion of laden with solid particles up to a particle size of 6 mm water through the pump. Since the height h of the wings 21 at the peripheral outlet of the flow channels 23 at least equal to the width b, so b is less than or equal to h, clogging of the flow channels is also avoided with respect to the height dimensioning.

Due to the wide open conical shape of the mating surface 12 and the adapted thereto training the height extension of the wings 21 of the Cross-section of the flow channels in the flow direction from the center of the impeller 2 radially outward to the peripheral output of the flow channels in the illustrated embodiment reduced by 24%. This cross-sectional reduction surprisingly leads to an increase in performance of the pump.

Compared with the current current generation of applicant's pond pumps with free-flow wheels, improvements shown below in Table 1 result in products according to the application. Under the column "Pump Types", the respective projected successor model is listed under the heading "Meßner M or MPF ..." pump types previously sold by the applicant and under "NEW ...". As can be seen from the table, can be achieved with the application according to the design of impeller and associated pump housing with mating plate considerable improvements in efficiency. Due to a considerably lower electrical power consumption with comparable pump performance, namely delivery head and delivery rate, there is a blatant economic advantage over the life of the pump. <b><u> Table 1 Comparison efficiency </ u></b> Pumptype input Delivery height H max. Delivery rate Q max. comment Messner MPF 3000 40W 2,5m 3000l / h With the same power consumption, the head H has increased by 0.4m and the output by 1680l / h. NEW 4500 40W 2,9m 4680l / h Messner MPF 6000 95W 3,5m 6000l / h Compared to the MPF 6000, with 15W lower power consumption, the head is increased by 0.5m and the output by 1560l / h. Compared with the MPF 8000, with a lower power consumption of 35W at the same delivery height, the delivery capacity is reduced by 540l / h, which in this regard is considered to be low. Messner MPF 8000 115W 4,0m 8100l / h NEW 7500 80W 4,0m 7560l / h Messner MPF 10000 135W 4,5m 9900l / h Compared to the MPF 10000, the power consumption is 31 W lower; In addition, the delivery height has increased by 0.7 m and the delivery capacity by 900 l / h. NEW 10000 104W 5,2m 10800l / h Messner MPF 13000 175W 5,0m 12600l / h Compared to the MPF 13000, the power consumption is 50W lower; In addition, the head has risen by 0.6m. The delivery rate has remained the same. NEW 13000 125W 5,6m 12600l / h Messner M 15000 285W 6,0m 16000l / h Compared with the M 15000, the power consumption is 100W lower; Funding and delivery has remained the same. NEW 16000 185W 6,0m 16000l / h Messner M 20000 400W 6,5m 20400l / h Compared with the M 200000, the power consumption is 200W lower; for that, the delivery height has dropped by 1.5m and the delivery rate has dropped by 1400l / h. NEW 20000 200W 5,0m 19000L / h

LIST OF REFERENCE NUMBERS

1

pump housing

11

suction inlet

12

Mating plate

13

plenum

14

pressure outlet

2

Wheel

21

wing

22

disc

23

flow channel

24

drilling

25

shaft

α

angle

b

width

H

Leaf height

s

clearance

W _D

Water drainage (pressure side)

Ws

Water inflow (suction side)

X

axis of rotation

Y

Drive side / drive unit

Claims (10)

1. A pond pump comprising an impeller (2) rotating around an axis of rotation (X) in a pump housing (1),
   wherein the pump housing (1) has a suction inlet (11) arranged axially with respect to the impeller (2), a pressure outlet (14) for the water to be delivered arranged radially to tangentially with respect to the impeller (2), and a housing portion between the suction inlet (11) and the pressure outlet (14),
   wherein the impeller (2) has a radially arranged circular disc (22) comprising vanes (21) arranged on one side thereon,
   and wherein the housing portion is coordinated with the open side of the impeller (2) which is equipped with the vanes (21) and is a flat counter-rotating plate (12), and wherein flow channels (23) are formed between the vanes (21), the circular disc (22) and the counter-rotating plate (12), characterised in that the flow channels (23) have a cross-section which reduces in the flow direction from the radial inner side to the outer side.
2. A pond pump according to Claim 1, characterised in that the reduction of the flow channel cross-section is 15% to 40%, preferably 20% to 35%.
3. A pond pump according to Claim 1 and 2, characterised in that the counter-rotating plate (12) is in the form of a wide open conical-surface portion with an angle (α) between 5° and 20° to the radial plane, oriented with respect to the axis of rotation (X), in the direction of the impeller.
4. A pond pump according to Claim 1, 2 or 3, characterised in that the circular disc (22) of the impeller (2) is in the form of a wide open conical surface with an angle (β) between 5° and 20° to the radial plane, oriented with respect to the axis of rotation (X), in the direction of the counter-rotating plate (21) [sic, recte (12)].
5. A pond pump according to Claim 3 or 4, characterised in that the height of the vanes (21) of the impeller (2), measured axially with respect to the axis of rotation (X), decreases from the radial inner side to the outer side, so that the open side of the impeller (2) is arranged so as to be spaced from the counter-rotating plate (12) with a substantially uniform clearance measurement (s).
6. A pond pump according to Claim 5, characterised in that the clearance measurement (s) is less than or equal to 1 mm, preferably less than 0.5 mm.
7. A pond pump according to Claim 5 or 6, characterised in that the height (h) of the vanes on the radial outer side is greater than or equal to the width (b) of the flow channels (23).
8. A pond pump according to one of the preceding claims, characterised in that the flow channels (23) formed between the vanes (21) have substantially the same width (b) from the radial inner side to the outer side of the impeller.
9. A pond pump according to one of the preceding claims, characterised in that the vanes (21) have a crescent-shaped cross-section in the radial plane with respect to the axis of rotation (X).
10. A pond pump according to one of the preceding claims, characterised in that the counter-rotating plate (12) is an integral component of the pump housing (1).

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