Spiral Pump, Device for Treatment of Water and Associated Method

Abstract

The invention relates to a spiral pump and a device for treating water comprising this spiral pump, and associated method. The spiral pump comprises: a housing provided with an inlet for water; and a pump body which is accommodated in the housing and rotatable around an axis, wherein the pump body comprises at least one spiral channel, wherein a first outer end of the at least one spiral channel is located on an outer side of the pump body and forms an entrance opening for alternately taking in water and air through rotation of the pump body in the housing, and a second outer end of the at least one spiral channel debouches into an outlet close to the axis, wherein the housing is embodied as pressure chamber and wherein the at least one channel is provided with an increasing diameter from the entrance openings in the direction of the axis.

Claims

1. Spiral pump, comprising: a housing provided with an inlet for water; and a pump body which is accommodated in the housing and rotatable around an axis, wherein the pump body comprises at least one spiral channel, wherein a first outer end of the at least one spiral channel is located on an outer side of the pump body and forms an entrance opening for alternately taking in water and air through rotation of the pump body in the housing, and a second outer end of the at least one spiral channel debouches into an outlet close to the axis, wherein the housing is embodied as pressure chamber, wherein the at least one channel comprises an increasing diameter from the entrance opening in the direction of the axis.

2. Spiral pump as claimed in claim 1, further comprising means for controlling a gas pressure in the housing, the means comprising a gas feed.

3. Spiral pump as claimed in claim 2, wherein the gas feed preferably comprises a pump.

4. Spiral pump as claimed in claim 2, wherein the means for controlling the gas pressure in the housing are configured to set the water level in the housing to a level at the height of the axis of the pump body.

5. Spiral pump as claimed in claim 4, the housing comprising an entry chamber which comprises the inlet and an exit chamber which is separated from the entry chamber and into which the outlet of the pump body debouches, wherein the gas feed is connected to the exit chamber for the purpose of pumping gas into the exit chamber, the housing further comprising a first conduit, of which a first outer end is positioned in the exit chamber at the height of the axis of the pump body and a second outer end is positioned in the entry chamber, and a second conduit, of which a first outer end is positioned in the entry chamber at the height of the axis of the pump body and a second outer end is positioned outside the housing.

6. Spiral pump as claimed in claim 1, wherein means are provided for setting the gas composition in the pressure chamber.

7. Spiral pump as claimed in claim 5, wherein the means for setting the gas composition preferably comprise means for setting the oxygen level in the pressure chamber.

8. Spiral pump as claimed in claim 1, wherein the pump body comprises at least one sheet-like wall which is wound into a spiral, which defines the at least one spiral channel

9. Spiral pump as claimed in claim 8, wherein the pump body comprises a number of sheet-like walls which are wound into a spiral and provided at a distance from each other so that a plurality of spiral channels are formed between the walls, wherein a first outer end of each channel is located on an outer side of the pump body and forms an entrance opening, and a second outer end of each channel debouches into the outlet close to the axis.

10. Spiral pump as claimed in claim 9, wherein the entrance openings are preferably distributed uniformly over the outer side of the pump body.

11. Spiral pump as claimed in claim 10, wherein the walls more preferably have substantially the same form and are rotated in each case through the same predetermined angle relative to each other.

12. Spiral pump as claimed in claim 1, wherein the at least one channel follows a Fermat spiral.

13. Spiral pump as claimed in claim 1, further comprising means for controlling the inflow speed of water into the inlet which are configured to adjust the inflow speed to 0.1-10 m/s.

14. Device for biological treatment of water comprising the spiral pump as claimed in claim 1.

15. Method for providing a spiral pump, comprising the following steps of: providing a housing embodied as pressure chamber with an inlet for water; and accommodating in the housing a pump body which is rotatable around an axis, wherein the pump body comprises at least one spiral channel, of which a first outer end is positioned on an outer side of the pump body and forms an entrance opening for alternately taking in water and air through rotation of the pump body in the housing, and a second outer end debouches into an outlet close to the axis, wherein the at least one channel is provided with an increasing diameter from the entrance openings in the direction of the axis.

16. Method as claimed in claim 15, further comprising of providing a pressure in the

17. Method as claimed in claim 16, further comprising of coupling the inlet of the housing to a basin with water to be treated and setting a desired water level in the housing by controlling the gas pressure in the pressure chamber, wherein the desired water level differs from the water level in the basin.

18. Method as claimed in claim 15, further comprising of controlling the gas composition in the pressure chamber.

19. Method as claimed in claim 18, wherein controlling the gas composition in the pressure chamber comprises controlling the oxygen content.

Description

[0070] Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings.

[0071] FIG. 1 shows a pump body of a spiral pump according to an embodiment of the invention;

[0072] FIG. 2 shows the interior of the pump body of FIG. 1;

[0073] FIG. 3 shows an exploded drawing of the pump body of FIGS. 1 and 2;

[0074] FIG. 4 shows a front view of the interior of the pump body of FIGS. 1-3;

[0075] FIG. 5 shows a side view of the pump body of FIGS. 1-4;

[0076] FIG. 6 shows a spiral pump according to an embodiment of the invention; and

[0077] FIG. 7 shows the spiral pump of FIG. 6 in a pond, wherein the water level in the spiral pump is lower than the water level in the pond.

[0078] In an embodiment pump body 2 (FIGS. 1 and 2) comprises three sheet-like walls 4a, 4b, 4c which extend in spiral form. Walls 4a, 4b and 4c are provided at a distance from each other, wherein the spiral forms are interleaved such that three spiral channels are formed between the walls. Covers 6a, 6b in the shape of discs are arranged on either side of the pump body. Discs 6a, 6b form the side walls of the spiral channels between walls 4a, 4b and 4c. Walls 4a, 4b, 4c are for instance welded along their whole length to discs 6a, 6b.

[0079] Each channel has an outer end which is located on the outer side of pump body 2 and there forms an entrance opening 8a, 8b, 8c. The three entrance openings 8a, 8b, 8c are distributed uniformly over the outer wall. The angle between two adjacent entrance openings is in each case 120 degrees.

[0080] Situated on a rear side of pump body 2a is an outlet 10. The channels defined between walls 4a, 4b, 4c debouch into this outlet 10. In the shown embodiment pump body 2 is provided on a shaft 12 to which pump body 2 is rigidly connected. Pump body 2 is rotated by rotation of shaft 12 with a drive. Shaft 12 is driven by a drive (not shown) which can for instance comprise an electric motor. In use pump body 2 will rotate as according to arrow A. In the shown embodiment shaft 12 is connected via spokes 14 to outlet 10.

[0081] As shown in FIG. 2, the outer ends of walls 4a, 4b, 4c optionally comprise strengthening ribs 16. Additionally or alternatively, it is possible to provide walls 4a, 4b, 4c with such strengthening ribs close to entrance openings 8a, 8b, 8c. Using the strengthening ribs walls 4a, 4b, 4c can be given a thin form while no sagging occurs.

[0082] The diameter of the channels preferably increases as seen from the periphery of pump body 2 in the direction of shaft 12. Diameter is understood in this context to mean the distance between the two walls 4a, 4b or 4c forming the associated channel Shown in FIG. 2 are successive distances d.sub.1, d.sub.2, d.sub.3, d.sub.4, d.sub.5 from the periphery of pump body 2 to central shaft 12 which are located on a line perpendicularly of shaft 12. As shown, it is the case that d1<d2<d3<d4<d5.

[0083] The diameter of the channels can alternatively take a substantially constant form, or the diameter can decrease in the direction of the shaft. A diameter of the channels increasing in the direction of the shaft does however have an advantage when the pump body 2 is applied in biological treatment, i.e. pump body 2 is less likely to become clogged.

[0084] Discs 6a, 6b are provided with spiral protrusions 18 (FIG. 3), also referred to as edge or ridge, for the purpose of supporting walls 4a, 4b, 4c.

[0085] In the shown embodiment the spiral walls 4a, 4b, 4c each follow a Fermat spiral (FIG. 4). The efficiency of spiral pump 20 is improved by an increasing diameter in accordance with a Fermat spiral.

[0086] Pump body 2 is mounted on shaft 12 which extends on either side beyond discs 6a, 6b (FIG. 5).

[0087] In an embodiment spiral pump 20 comprises a housing 22 which is divided into two chambers: an exit chamber 24 and an entry chamber 26. Chambers 24, 26 of housing 22 are separated by partition wall 28. Provided during use in housing 20 is water 30 which is introduced via an inlet (not shown) into entry chamber 26 of housing 22. Pump body 2 is situated in entry chamber 26 so that entrance openings 8a, 8b, 8c can alternately take air and water into entry chamber 26. Outlet 10 of pump body 2 protrudes however through wall 28 and thereby debouches into exit chamber 24. The water leaves exit chamber 24 via an exit (not shown) of this chamber 24. A seal is further provided on outlet 10 in exit chamber 24 between outlet 10 and partition wall 28.

[0088] Housing 22 is embodied as a pressure chamber. Provided in exit chamber 24 is a conduit 32, a first outer end of which is located at the height of the rotation axis of pump body 2. The other outer end of conduit 32 is located some distance above the first outer end and protrudes through wall 28 into entry chamber 26. Entry chamber 26 comprises a conduit 34, a first outer end of which is located at the height of the rotation axis of pump body 2, while the other outer end of conduit 34 debouches outside housing 22. A pump 36 is moreover provided which is configured to pump air or another gas into exit chamber 24 of housing 22.

[0089] In use pump body 2 is rotated by means of a drive which engages on shaft 12. Entrance openings 8a, 8b, 8c alternately take in air and water. Pump 36 pumps air continuously into exit chamber 24, whereby an overpressure is created in exit chamber 24. The air can leave exit chamber 24 via the first outer end of conduit 32 positioned at the height of the rotation axis of pump body 2. The water level in exit chamber 24 will hereby remain at the height of the rotation axis. The air introduced via conduit 32 into entry chamber 26 will there likewise create an overpressure, wherein it is generally the case that P.sub.exit chamber>P.sub.entry chamber. The air can escape from entry chamber 26 via a lower outer end of conduit 34 which is likewise positioned at the height of the rotation axis of pump body 2. The water level 30 in entry chamber 26 is thus also held at the height of the rotation axis of pump body 2. It is generally the case that P.sub.exit chamber>P.sub.entry chamber>P.sub.atmospheric. In short, the water level is set at the height of the rotation axis of pump body 2 by the supply of air by means of pump 36 and conduits 24 and 26. Pump body 2 is thus always roughly half under water.

[0090] Spiral pump 2 is for instance used for biological treatment of pond water (FIG. 7). The water level in housing 22 is lower than the water level in the pond. The difference h in water level is possible because of the pressure built up in the housing 22 embodied as pressure chamber. The pond water to be treated is carried via an feed conduit 38 into housing 22. Feed conduit 38 debouches into a lower part of entry chamber 26, i.e. at a height below water level 30. Treated water can be fed back to the pond via discharge conduit 40. Discharge conduit 40 is provided on an underside of exit chamber 24, i.e. at a height below water level 30. It is noted that due to the pumping action of spiral pump 20 no additional pumps are necessary to feed the water into and out of the pond.

[0091] In the shown embodiment pond water is guided directly to spiral pump 20. In practice a mechanical filter will usually be present so that solids are filtered out of the water before the water is treated by means of spiral pump 20. Further devices can optionally be provided for the treatment of the water prior to or following biological treatment by spiral pump 20.

[0092] The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged. It is for instance possible in an alternative embodiment to use the outlet of the pump body as inlet, wherein the entrance openings of the pump body and the inlet of the spiral pump are used as outlets. The rotation direction of the pump body is reversed in this alternative embodiment relative to the rotation direction of the pump body as shown in the figures. The conduits and gas feed which control the pressure in the chambers of the housing are preferably modified in such an alternative embodiment. The gas feed is connected to chamber 26, which in this alternative embodiment forms an exit chamber, conduit 32 is likewise positioned in chamber 26 and conduit 34 is positioned in chamber 24, which in this alternative embodiment forms an entry chamber. The pressure in the exit chamber is in this way also higher in the alternative embodiment than the pressure in the entry chamber, which in turn is again greater than the atmospheric pressure.