Sinking pump safe for fish

Abstract

 The invention relates to a sinking pump, comprising:
- a tubular housing with a feed opening and a discharge opening;
- at least one drivable pump rotor arranged in the tubular housing;

wherein the pump rotor comprises a cylindrical casing, which casing lies sealingly against the inner wall of the tubular housing.
The invention further relates to a pumping station for pumping surface water from a lower level to a higher level, comprising a sinking pump according to any of the foregoing claims.

Description

[0001] The invention relates to a sinking pump comprising:

• a tubular housing with a feed opening and a discharge opening; and
• at least one drivable pump rotor arranged in the tubular housing.

[0002] Such sinking pumps are frequently used in pumping stations to pump surface water from a lower level to a higher level. The pump rotor consists of a hub on which a number of blades are arranged. In order to obtain sufficient head with such a pump rotor, the rotation speed of the pump rotor is high.

[0003] The drawback of such known sinking pumps is that the fish present in the surface water cannot swim unharmed through a sinking pump. Owing to the difference in speed between the stationary tubular housing and the rotating pump rotor the fish comes between the ends of the blades of a pump rotor and the housing. The high rotation speed of the pump rotor moreover means that the fish are more likely to be struck by a blade of the pump rotor.

[0004] Legislation requiring pump devices in for instance pumping stations to be fish-friendly has resulted in a desire for an improved sinking pump which makes it possible for fish to swim through the sinking pump.

[0005] According to the invention the pump rotor comprises a number of blades. The blades are spiral-shaped and their effective surface area increases in pumping direction. Owing to the spiral shape and the increase of the effective surface area a considerable pump flow rate can still be obtained.

[0006] Preferably the pump rotor comprises a cylindrical casing, which casing lies sealingly against the inner wall of the tubular housing.

[0007] Due to a casing being arranged around the pump rotor it is no longer possible for the fish to be caught between the ends of the blades of a pump rotor and the stationary pump housing. The fish can now swim along without problem with the flow of water displaced in the tubular housing by the pump.

[0008] In an embodiment of the sinking pump according to the invention a drive shaft is arranged axially in the tubular housing for the purpose of driving the pump rotor.

[0009] In a preferred embodiment of the sinking pump according to the invention a number of pump rotors are arranged successively in the tubular housing as seen in axial direction. The advantage hereof is that the head of a single pump rotor can remain limited, since only the combination of the different pump rotors in the tubular housing together have to achieve a desired head. An additional advantage is that the rotation speed of the pump rotors can hereby be reduced. This has a positive effect on the fish passing through the sinking pump.

[0010] In yet another embodiment of the sinking pump according to the invention the spiral-shaped blades taper in the pumping direction from the hub toward the casing.

[0011] In yet another embodiment of the sinking pump according to the invention the spiral-shaped blades taper in the pumping direction from the casing toward the hub.

[0012] The sinking pump according to the invention can further comprise a generator coupled to the pump rotor. It hereby becomes possible to generate energy, for instance by having water flow from a higher level to a lower level.

[0013] The invention further comprises a pumping station for pumping surface water from a lower level to a higher level, comprising a sinking pump according to the invention.

[0014] These and other features of the invention are further elucidated with reference to the accompanying figures.

Figure 1 shows a pumping station according to the invention having therein a sinking pump according to the invention.

Figures 2-4 show a first embodiment of a pump rotor for a sinking pump according to the invention.

Figures 5-7 show a second embodiment of a pump rotor according to the invention.

Figure 1 shows a pumping station 1 according to the invention. This pumping station 1 has a sinking pump 2 according to the invention. Sinking pump 2 pumps surface water 3 from a lower level over a dike body 4 to surface water 5 at a higher level.

[0015] Sinking pump 2 has a tubular housing 6 in which three pump rotors 7 are arranged on an axial drive shaft 8. Drive shaft 8 is driven by a motor 9.

[0016] Figure 2 shows a perspective view of a pump rotor 7 for a sinking pump 2 according to the invention. Pump rotor 7 has a hub 10 on which a number of blades 11 are arranged. Arranged around these blades 11 is a cylindrical casing 12 which is attached to the blades. This cylindrical casing 12 has a diameter which is substantially equal to the internal diameter of tubular housing 6 of sinking pump 2. A seal can optionally be provided between cylindrical casing 12 and tubular housing 6. Figure 3 shows a front view of pump rotor 7, i.e in pumping direction P, where the water first comes into contact with pump rotor 7. As can be seen, blade 11 starts from hub 10 and then tapers spirally to the rear side of pump rotor 7. Figure 4 shows the view in pumping direction P on the rear side of pump rotor 7. It will be apparent that the effective surface area of blades 11 increases from hub 10 toward casing 12.

[0017] Figures 5-7 show a second embodiment of a pump rotor 13. Also present here is a hub 14 on which blades 15 are arranged. The blades are enclosed by a cylindrical casing 16. As shown clearly in figure 6 and figure 5, blades 15 are spiral-shaped and taper from casing 16 to hub 14. As shown in figure 7, the surface area of blades 15 increases here in the pumping direction P.

[0018] The sinking pump can also be used as generator, for instance in the embodiment according to figure 1. Motor 9 must here be replaced with a generator. Surface water 5 can then be guided from the higher level, through the sinking pump to lower level 3. Pump rotor 7 is herein driven, and thereby the generator.

[0019] A hybrid form with a motor 9 and a generator is also possible.

Claims

1. Sinking pump, comprising:

a tubular housing with a feed opening and a discharge opening;

at least one pump rotor arranged to be driven at a high rotation speed arranged in the tubular housing;

wherein the pump rotor comprises a hub on which a number of blades are arranged;

wherein the blades are spiral-shaped and increase in effective surface area in pumping direction.

2. Sinking pump as claimed in claim 1, wherein the blades start from the hub and then taper spirally to the rear side of the pump rotor.

3. Sinking pump as claimed in claim 1 or 2, wherein the pump rotor comprises a cylindrical casing, which casing lies sealingly against the inner wall of the tubular housing.

4. Sinking pump as claimed in claim 3, wherein the spiral-shaped blades taper in the pumping direction from the hub to the casing.

5. Sinking pump as claimed in claim 3, wherein the spiral-shaped blades taper in the pumping direction from the casing to the hub.

6. Sinking pump as claimed in any of the foregoing claims, wherein a drive shaft is arranged axially in the tubular housing for the purpose of driving the pump rotor.

7. Sinking pump as claimed in any of the foregoing claims, wherein a number of pump rotors are arranged successively in the tubular housing as seen in axial direction.

8. Sinking pump as claimed in any of the foregoing claims, comprising a generator coupled to the pump rotor.

9. Pumping station for pumping surface water from a lower level to a higher level, comprising a sinking pump as claimed in any of the foregoing claims.

Drawing