EP3405677B1 - Venting device for pump in a container - Google Patents

Description

The invention relates to a system with a container and an arrangement, which has a centrifugal pump, which is arranged in the container, and a motor for driving the centrifugal pump, which is arranged above the centrifugal pump, the centrifugal pump having an impeller and a first housing part ,

Such systems can be designed in particular as wastewater lifting plants. These discharge water that accumulates below the backflow level backflow-proof. They are used to pump sewage that is free of faeces and contains faeces, which accumulates in the basements of residential buildings. The waste water is collected in a container. The fill level is usually recorded using a level sensor. If a certain limit is reached, a centrifugal pump switches on, which pumps the waste water out of the tank.

The container has a receptacle for an arrangement. The arrangement, which comprises a centrifugal pump driven by a motor, is immersed in the waste water. The engine protrudes from the container. The impeller of the centrifugal pump is surrounded by a housing part.

The DE 10 2007 008 692 A1 shows a sewage lifting plant with a container in which sewage collects. At the top of the container, an opening is provided, into which an arrangement projects, which has a centrifugal pump with a motor. The centrifugal pump comprises a housing part in which an impeller is arranged. The housing part with the impeller protrudes into the waste water. The wastewater is sucked in via a suction nozzle and transported out of the tank by the centrifugal pump. The motor of the arrangement is connected to the impeller via a shaft.

The arrangement, consisting of the pump housing with the impeller and the motor connected via a shaft, forms a unit. The motor part protrudes from the container. The arrangement is supported by flange rings or plates. Sealing devices are arranged between the flange rings or plates and the container, so that neither wastewater nor unpleasant smells escape from the container.

In the DE 199 13 530 A1 describes a wastewater lifting plant with a container that holds liquid that flows to the container at irregular intervals and in different amounts. The system comprises an arrangement with a pump and a drive part. The pump transports liquid from the container into a sewer network. The pump housing with the suction nozzle protrudes into the container. The drive part of the pump protrudes from the container.

In systems with self-priming pumps that are integrated in a container, air often collects in the pump. Therefore, ventilation is required, which serves to discharge gas or air accumulations and thus enables the necessary filling with a pumped medium before starting the centrifugal pump.

In conventional sewage pumps, ventilation is ensured, for example, by open lines with a correspondingly large diameter. The resulting leakage water flow is accepted or returned to the inlet chamber. If centrifugal pumps are installed above the water level on the suction side and their suction line has a foot valve, they are filled by hand using a filling funnel on the pump suction nozzle or via a ventilation system, provided that they are not self-priming.

The pump room can be partially or completely filled with air, especially when starting up for the first time and when the tank is low. The accumulated air must be removed before or during the start of the system.

In conventional systems according to the prior art, this is solved, for example, by means of bores which are arranged in such a way that they either lie inside the container or are connected to the container by means of a hose or the like.

In the DE 29 13 967 A1 describes a wastewater lifting plant in which a bore is arranged in a main chamber cover plate, to which a connection piece is connected, which is connected to a pump ventilation hose. The pump ventilation hose opens into a bend screwed onto the pressure flange of the centrifugal pump.

In the DE 29 13 970 A1 describes a wastewater lifting plant with a container for storing irregular wastewater. The wastewater lifting plant comprises a pump that is driven by a vertical shaft. The pump housing comprises a venting device which has a protective device against clogging by solids in the waste water.

In conventional wastewater lifting plants, bores are often drilled in the pressure line. This can clog the ventilation holes, in particular in the case of fibrous solids.

If the ventilation is arranged in the room behind the impeller, a vacuum can be created, particularly in the case of impellers with ribs on the back, which draws air.

Examples of such pumps are from the documents DE 295 22 235 U1 . DE 2 228 305 A1 . US 2,850,984 A and DE 10 2008 016 476 A1 known.

The object of the invention is to provide a system which has a reliable mode of operation and the highest possible efficiency, even when conveying media containing solids, in particular fibers. The system should have the lowest possible noise level during operation.

This object is achieved according to the invention by a system with the features of claim 1. Preferred variants can be found in the subclaims, the descriptions and the drawings.

The system has an arrangement with a centrifugal pump, which comprises a housing part which has a vent at the level of the impeller and / or above the level of the impeller. The term "height" is understood as a perpendicular distance to a reference point. The individual components of the arrangement are arranged with increasing height in the following order: inlet for medium, impeller with the first housing part, further housing part, motor. The impeller is driven by a vertical shaft that is aligned vertically.

The integration of a ventilation device in the first housing part, at the level of the impeller or above, enables effective ventilation of the centrifugal pump and at the same time reduces the risk of clogging of the ventilation devices. Surprisingly, it was found that an arrangement of the venting device in this position contributes to flushing or tearing off blockages and in this way a reliable venting of the pump is permanently guaranteed. A high flow velocity in the radial direction prevents blockages in this area.

The venting device according to the invention is particularly suitable for lifting systems with a cutting unit, in particular for material containing fibers.

A gap for reducing the pressure is preferably formed between the impeller and a region of the first housing part. This also reduces the volume flow, which also has a favorable effect on avoiding blockages during ventilation.

The venting device preferably comprises at least one opening. The vent can also be formed by the opening itself through which the air that has accumulated in the pump can escape.

In a particularly advantageous embodiment of the invention, the ventilation acts in the radial direction. By introducing a vent in a housing part in the radial direction at the level of the impeller or above the impeller, there is a radially directed leakage flow.

According to the invention, the ventilation device is arranged in such a way that the resulting leakage flow is directed to a line element, it proving to be particularly favorable if the leakage flow is directed to a pressure port of the centrifugal pump.

In conventional systems, the problem often arises that a leakage flow hits a container wall. Since the container acts as a resonance body, undesirable noise is generated. The leakage flow is limited or spread by aligning the ventilation to a line element of the system.

The arrangement preferably comprises a further housing part which is arranged above the first housing part, it proving to be advantageous if the further housing part is designed as a cover component. The lid component forms a cover for an opening of the container, which forms a receptacle for the arrangement. The cover component can be designed, for example, as a pressure cover. The lid component supports the arrangement and has areas which rest on the upper side of the upper container wall, so that part of the arrangement projects into the container and part of the arrangement is arranged above the container opening and thus protrudes above the receptacle.

The cover component can also serve as a bearing bracket.

In a particularly advantageous variant of the invention, the first and the further housing part overlap with one another. For this purpose, the first housing part can have a region which forms a receptacle for a region of the further housing part or, conversely, a region of the first housing part engages in a receptacle of the further housing part.

The first housing part is preferably designed as a spiral housing which at least partially surrounds the impeller. The volute casing can have an impeller fitting as an area. The impeller fitting forms a receptacle in that an area of the further area designed as a pressure cover engages. This area of the pressure cover is also referred to as the pressure cover fit. In this variant, the impeller fit of the volute casing and the pressure cover fit overlap.

The ventilation device can be arranged in addition to the first housing part in at least one further housing part. If two housing parts overlap, it proves to be advantageous if ventilation openings are introduced in both housing parts, which are aligned with respect to one another in such a way that the leakage flow flows through the two openings from the interior of the centrifugal pump into the container and thus ensures that the centrifugal pump is vented becomes.

The arrangement is preferably designed as a centrifugal pump unit, which forms a unit that can be completely assembled or disassembled.

It proves to be advantageous if the motor is at least partially arranged outside the container. In one variant, the motor is positioned completely outside the container.

The impeller of the centrifugal pump is connected to the motor via a vertical shaft arrangement. A gap for pressure reduction and / or volume reduction is preferably formed between the impeller and a region of the first housing part. In addition to the ventilation device described above, a gap for ventilation can be arranged between a line element of the system and a component. The gap between this line element and the component is preferably annular. It proves to be particularly advantageous if this line element and the component have a circular cross section or are designed like a hollow cylinder. A leakage flow occurs through the annular gap for ventilation, which creates a liquid carpet. With this construction, a seal is no longer required between this line element and the component.

In a particularly favorable variant, this line element and the component are arranged at a distance from one another. The transition from this line element and the component is used for this, so that a defined annular gap is created. They are preferably at an axial and / or radial distance from one another. In a favorable embodiment, the distance is less than 2 mm, preferably less than 1 mm, in particular less than 0.5 mm. It proves to be particularly advantageous if the distance is more than 0.01 mm, preferably more than 0.05 mm, in particular more than 0.08 mm.

It proves to be particularly advantageous if this line element and / or the component has a surface which delimits the gap and is not planar. For this purpose, for example, recesses can be made in the abutting end faces of this line element and / or component. Such a construction ensures reliable venting without the capillary action of the medium or the surface tension reducing the venting action of the gap. In a variant of the invention, the annular gap has one or more notches. The notches are created by making recesses in this line element and / or the component immediately adjacent to it.

Further features and advantages of the invention result from the description of an exemplary embodiment with reference to drawings and from the drawings themselves.

Figur 1

eine perspektivische Ansicht des Behälters der Anlage,

Figur 2

eine Seitenansicht der Anordnung,

Figur 3

eine perspektivische Ansicht der Anordnung von unten,

Figur 4

eine Schnittdarstellung der Anlage,

Figur 5

einen Axialschnitt der Kreiselpumpe,

Figur 6

einen Radialschnitt durch die Anordnung entlang der A-A Linie gemäß Figur 5,

Figur 7

eine perspektivische Darstellung eines weiteren Gehäuseteils von oben,

Figur 8

eine perspektivische Darstellung des weiteren Gehäuseteils von unten.

It shows:

Figure 1

a perspective view of the container of the system,

Figure 2

a side view of the arrangement,

Figure 3

a perspective view of the arrangement from below,

Figure 4

a sectional view of the system,

Figure 5

an axial section of the centrifugal pump,

Figure 6

a radial section through the arrangement along the AA line according Figure 5 .

Figure 7

a perspective view of another housing part from above,

Figure 8

a perspective view of the further housing part from below.

Figure 1 shows a container 1 of a sewage lifting plant. In the exemplary embodiment, it is a plastic container that is designed for unpressurized operation. Waste water is temporarily stored in the container 1 and then conveyed into a sewer.

The container 1 has an area of higher construction with two inlets 2 and an area of lower construction. Furthermore, the container 1 has an emptying connection 3 and a hand hole 4, which is closed by a lid, which in Figure 1 is not shown.

In Figure 1 the part of a sensor module 5 protruding from the container 1 can be seen, which in the exemplary embodiment is used as a level measuring device for detecting the Level is executed. For example, a float switch is used.

Furthermore, the container 1 has a vent connection 6. The waste water collected in container 1 is conveyed out via an outlet arranged on container 1.

The lower part of the container 1 in terms of its height has a receptacle 8 for an in Figure 2 arrangement 9 shown. In the exemplary embodiment, the receptacle 8 is designed as a circular opening on an upper side of the container 1.

In the Figure 2 The arrangement 9 shown comprises a centrifugal pump 10 with a first housing part 11 designed as a spiral housing, a further housing part 12 designed as a pressure cover and a motor 13.

A pipeline 15 connects to a line element 14 for discharging the medium collected in the container 1. The line element 14 is designed as a pressure port.

Figure 3 shows a perspective view of the arrangement from below. The arrangement 9 has a cutter 16 for comminuting solid components of the medium. The medium flows into the centrifugal pump 10 through openings 17 in a housing part 18. The housing part 18 is designed as an impeller body.

The further housing part 12 has areas 19 with which the arrangement rests on the upper container wall.

Figure 4 shows a longitudinal section through the sewage lifting plant. The arrangement 9 lies with an area 19, which are formed by the further housing part, on an upper container wall. The arrangement 9 is connected to the container 1 by means of fastening means 20. The fastening means 20 can be screws, for example.

The motor 13 is surrounded by a motor housing 21. The motor 13 is an electric motor that has a stator and a rotor. The motor 13 drives a shaft 22 which is supported by a bearing arrangement 23.

The shaft 22 is connected to an impeller 24.

The medium flows to the impeller 24 through openings 17. The impeller 24 is surrounded by a first housing part 11, which is designed as a spiral housing. The first housing part 11 has a region 25 which is designed as an impeller fitting in the exemplary embodiment. Furthermore, the first housing part 11 has a suction area 26. The suction region 26 is designed like a hollow cylinder and at least partially surrounds the cutting unit 16.

The impeller 24 is designed as a radial impeller and conveys the medium via the angled line element 14 into a pipeline 15.

Figure 5 shows a longitudinal section showing part of the centrifugal pump 10 in an enlarged view. According to the invention, the first housing part 11 has a vent 27 above the impeller 24. In the exemplary embodiment, the vent 27 is designed as an arrangement of openings which are aligned with respect to one another and which are introduced in the region 25 of the first housing part and in a region 28 of the second housing part 12. The area 28 is designed as a pressure cover fitting.

Gases in the pump escape through the vent 27 and flow through the first opening in the first housing part 11 and then through the second opening in parallel in the outer further housing part 12 into the container 1.

Figure 6 5 shows a radial section through the arrangement along the AA line according to FIG. 5 of a section of the centrifugal pump 10 which has the vent 27. According to the invention, the vent 27 is directed onto the line element 14. The one from the vent 27 radially escaping leakage flow is spread and braked by the line element 14, so that noise is significantly reduced.

Figure 7 shows the further housing part 12 from above, which is designed in the embodiment as a pressure cover. The further housing part 12 is a one-piece component, which is preferably made of a metallic material, in particular a cast.

The further housing part has a first hollow-cylindrical section 29 with a larger diameter, which is open toward the motor 13, and a second cylindrical section 30, which serves as a bearing bracket for a bearing arrangement 23 of the shaft 22. A connector 31 is formed from the further housing part 12 for connection to the line element 14 and the pipeline 15.

Figure 8 shows the further housing part 12 from below. Figure 8 shows an opening of the vent 27, which is designed in the exemplary embodiment as an aligned arrangement of openings. The opening is made in a region 28 of the second housing part 12. The area 28 is designed as a pressure cover fitting.

LIST OF REFERENCE NUMBERS

1

container

2

inlets

3

drain connection

4

hand hole

5

sensor module

6

exhaust port

8th

admission

9

arrangement

10

rotary pump

11

first housing part

12

another housing part

13

engine

14

line element

15

pipeline

16

cutting

17

openings

18

housing part

19

areas

20

fastener

21

motor housing

22

wave

23

bearing arrangement

24

Wheel

25

Area

26

suction

27

vent

28

Area

29

first cylindrical section

30

second cylindrical section

31

connector

Claims (14)

1. System comprising a container (1), a line element (14) and an assembly (9), which has a centrifugal pump (10), wherein the centrifugal pump and the line element are arranged in the container (1), wherein the assembly has a motor (13) for driving the centrifugal pump (10), said motor (13) being arranged above the centrifugal pump (10), wherein the centrifugal pump (18) has an impeller (24) and a first housing part (11),
   and wherein
   the first housing part (11) has at least one evacuation feature (27) at the level of the impeller (24) and/or above, characterized in that the evacuation feature (27) is directed toward the line element (14).
2. System according to Claim 1, characterized in that the evacuation feature (27) has at least one opening.
3. System according to Claim 1 or 2, characterized in that the evacuation feature (27) acts in a radial direction.
4. System according to one of Claims 1 to 3, characterized in that the assembly (9) has a further housing part (12), which is arranged above the first housing part (11).
5. System according to Claim 4, characterized in that the further housing part (12) is designed as a cover component.
6. System according to Claim 4 or 5, characterized in that the evacuation feature (27) is arranged adjacent to the first housing part (11), at least in the further housing part (12).
7. System according to one of Claims 4 to 6, characterized in that the first housing part (11) has at least one region (25) which overlaps with the further housing part (12).
8. System according to one of Claims 1 to 7, characterized in that
   the motor (13) is arranged at least partially outside the container (1).
9. System according to one of Claims 1 to 8, characterized in that the motor (13) is arranged completely outside the container (1).
10. System according to one of Claims 1 to 9, characterized in that the motor (13) is connected by a vertical shaft (22) to the impeller (24) of the centrifugal pump (10).
11. System according to one of Claims 1 to 10, characterized in that the container (1) has a receptacle (8) for the assembly (9).
12. System according to one of Claims 1 to 11, characterized in that a gap for pressure reduction and/or volume reduction is formed between the impeller (24) and one region of the first housing part (11).
13. System according to one of Claims 1 to 12, characterized in that the first housing part (11) at least partially surrounds the impeller (24).
14. System according to one of Claims 1 to 13, characterized in that the first housing part (11) is designed as a volute housing.

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