EP2245312A1

EP2245312A1 - Degassing device for liquid-filled chambers with rotating components

Info

Publication number: EP2245312A1
Application number: EP09744087A
Authority: EP
Inventors: Lutz Urban; Steffen Prager
Original assignee: KSB AG
Current assignee: KSB AG
Priority date: 2008-11-12
Filing date: 2009-10-30
Publication date: 2010-11-03
Anticipated expiration: 2029-10-30
Also published as: CN102216624A; SI2245312T1; DE102008056855A1; ES2375911T3; ATE535716T1; WO2010054753A1; CN102216624B; HRP20120035T1; DK2245312T3; PT2245312E; CY1112258T1; PL2245312T3; EP2245312B1

Abstract

The present invention relates to a degassing device which is composed of a housing with a chamber with a rotating component arranged therein, in particular a shaft, a bearing arrangement and/or a shaft seal. At least one rib, which extends with a free rib end up to the rotating component so as to form an axially parallel gap, is attached in the chamber. Positioned downstream of the gap is a degassing chamber for a liquid. A jet splitter wall surface (18) for splitting up a gap jet (17) is arranged in the chamber (2) at a distance from an acceleration gap (14) and opposite the acceleration gap (14). At a lateral distance from a gap projection (B) onto the jet splitter wall surface (18), said jet splitter wall surface (18) is provided with one or more connecting openings (15) to the degassing chamber.

Description

KSB Aktiengesellschaft 67227 Frankenthal

Degassing device for liquid-filled rooms with rotating components

description

The invention relates to a degassing device, comprising a housing having a space with a rotating component arranged therein, in particular a shaft, a bearing and / or a shaft seal, wherein in space at least one with a free rib end forming an axis-parallel gap to the rotating component approaching rib is attached, and that the gap is followed by a degassing space for a liquid.

From EP 0 327 549 B1 a degassing device for a pump shaft with mechanical seal is known for a centrifugal pump for conveying hot liquids with at least one shaft passage through a pump housing. For this purpose, the mechanical seal is surrounded by a concentric annular wall arranged at a distance therefrom, with radial ribs projecting outwards and inwards. The separated from the annular wall spaces are interconnected by holes. With this degassing a calming of the liquid circulation in distance from the mechanical seal should be done. This separated gases collects a large-volume, flow-calm and ventilated receiving space, which is provided with means for removing accumulated gas. Such a solution requires a lot of space and is expensive to produce. Another degassing device for a pump shaft is known from DE 198 34 012 C2. In this centrifugal pump with conveyed in a sealing space liquid for a therein provided mechanical seal of a pump shaft, the seal chamber provides two longitudinally approximately parallel to the pump shaft extending, blade-like and different length patches before. The blade-like surface pieces are arranged on the peripheral wall of the sealing space on both sides of a vent opening and attached to an end wall and preferably inclined at an angle of about 80 ° to each other. They form between them and the peripheral wall in an approximately triangular cross-section antechamber. At the location of the successive free ends of the patches, these form between them an intake gap approximately parallel to the pump shaft for the vestibule. Through this gap, liquid flows radially into the vestibule, where it remains calm. The separated gas is removed via the vent.

The previously known, provided with sedatives degassing devices rely on a horizontal shaft arrangement to provide a vent for a gas in each upper part of the seal chambers.

The problem addressed by the invention is to develop a venting device which is reliably endangered by gas-containing or outgassing liquids and has a reliably acting in various installation positions as well as being easy to produce.

The solution to this problem provides for a degassing, that in the space in the direction of rotation of the rotating part and at a distance from the gap and the gap opposite a beam splitter wall surface is arranged and that in a lateral distance to a slit projection on the beam splitter wall surface this is provided with one or more connecting openings to the degassing space. Due to the or parts rotating in space, a liquid contained therein is rotated and flows through the gap cross section. As a result, a gap beam is formed corresponding to the gap length and shape, which emerges approximately tangentially to the rotating part of the gap. The slit beam hits the gap lying on the opposite beam splitter wall surface, in particular in the direction of a normal, and it is split on impact primarily in two flowing in opposite directions streams. In the flow direction behind the rib forming the gap there is a vacuum chamber, in which a vacuum zone is formed. Therein, at least one vortex roll forms, which is excited by the partial flow of the split jet. This vacuum zone accelerates in a previously unknown manner a degassing in a liquid.

According to embodiments, the rib reaches close to the rotating component as a rotation axis-close housing rib to form an acceleration gap. Depending on its rotational speed and gap width, a liquid passing therethrough is accelerated therein and formed as a directed jet within the liquid in the space. Due to the fact that the beam splitter wall surface is arranged at an angle to the splitting beam emerging from the gap, the beam splitting and a whirl roller formation generated thereby are influenced as a function of an angle of inclination selected relative to the beam direction. The slit beam is mostly normal on the beam splitter wall surface. A selected tilt of the beam splitter wall surface is on the order of an acute angle to the normal of the slit beam. Its magnitude can be in the range up to 25 °.

The beam splitter wall surface is formed as part of a rotation axis-far housing wall or housing rib. In particular, the use of a housing rib facilitates the formation of the housing as a cast construction. Costly welding or assembly work is thus eliminated. The beam splitter wall surface is considered or considered to be a passant with respect to the rotating component and viewed in cross-section. Their arrangement is chosen so that it does not even cut the rotating components. If the beam splitter surface has an inclination or a curved shape, then an extension of this surface can intersect the rotating components. In a spatial view of this degassing the gap-limiting rotational axis-near housing rib and the beam splitter wall surface are arranged within a spatial housing quadrant of the room. According to other embodiments, the free ends of the housing ribs have an opposite extension direction. In the space between the housing rib and the beam splitter wall surface and on the rotation axis-distant side of the beam, a negative pressure space is formed. In this vacuum chamber, a partial jet emanating from the beam divider wall surface forms a turbulence roller, whereby a defined vacuum zone exists within the vacuum chamber. As a result, a very fast degassing of the liquid is achieved. In complete contrast to the solutions known hitherto, rotation in the space with the rotating internals is not prevented, but is used specifically to form an accelerated slit jet and thus generates an additional swirling roller for degassing purposes.

Furthermore, the vacuum chamber extends in the direction away from the rotating component. This spacing supports a degassing process. And the rotationsachsen- remote housing wall or housing rib with the beam splitter wall surface can form a wall of the degassing chamber, if it is formed as an integral part of the degassing. With respect to the axis of rotation, the vacuum space is located between the fin near the axis of rotation and the degassing space remote from the axis of rotation.

According to further embodiments, the degassing space is provided with a degassing opening. For use with shafts with double seals, two or more degassing devices are arranged one behind the other in the axial direction and each degassing space is provided with a degassing opening. If only one shaft seal is used in such a design, a separating wall is arranged between two degassing spaces and the degassing opening can be located in the T-shaped connecting region between the dividing wall and the outer wall. Due to their position in the crossing area between the housing wall and the dividing wall as well as over the dividing wall, a connection between two spaces is produced with only one machining operation. With only one vent can therefore be removed from two rooms simultaneously a gas accumulation. In order to achieve a safe degassing both in a horizontal, a vertical or a diagonal arrangement of the rotating parts, a degassing opening extending at an angle to the axis of rotation is arranged at an axial end region of a degassing space. Furthermore, the degassing space can be an integral or separate component of the housing.

The effect of the degassing support further embodiments, according to which the space surrounding the rotating parts, in particular its peripheral wall surface, wholly or partially has a helical formation. This is done within a spiral space thus formed, a conversion of the velocity energy of the rotating liquid in pressure energy, which then acts on the acceleration gap on the gap beam and amplifies it. In addition, the pressure difference between the space or the spiral space formed therein and the vacuum space increases, whereby the degassing operation is accelerated in the vacuum space. For this purpose, the rotation axis-near housing rib is arranged in a spiral-shaped space in the region of the spatial housing quadrant, which has the largest radial extent with respect to the axis of rotation.

Depending on the desired degassing time and inclination of the beam splitter wall surface in relation to the incident gap beam, partial streams flowing therefrom are to be assessed as a type of main and secondary flow. The main stream here is the gas-laden, rotating with the component and around it forming part of the flow called. As a side stream of the beam splitter wall surface in the vacuum space overflowing partial flow is referred to, which generates there used for degassing the whirl roll. This swirling roll has a direction of rotation which is opposite to the liquid ring rotating in space. This held at the site of the vacuum space vortex roll causes in a very short time a degassing of the entire liquid located in the degassing.

For this purpose, according to a further embodiment, the beam splitter wall surface and / or its extension arranged in the direction of the connection opening adjoin a beam-dividing inner wall delimiting the vacuum space and along the beam splitting end Inside wall, a partial flow of a spinning roller rotating in the vacuum space flows into the degassing space. This partial stream originates from the gas-enriched multi-phase mixture flow rotating in the swirling roll. Their gas components flow from the vacuum space via one or more connecting openings in the degassing space and are there removably accumulated. Due to the formation of a vacuum chamber with a whirl roll held therein, this solution is reliable in any shaft arrangement.

Further embodiments of the invention are described in the subclaims.

Embodiments of the invention are illustrated in the figures and will be described in more detail below. It show the

1 is a longitudinal section through the degassing of a centrifugal pump,

Fig. 2 & 3 cross sections through the gap zone of the degassing, the

4 shows a degassing device for a horizontal, diagonal or vertical shaft arrangement and FIGS

Fig. 5 & 6 a degassing device for shaft seals in tandem or single arrangement.

In Fig. 1, a degassing is shown using the example of a drive shaft for a centrifugal pump. The degassing device is arranged in a housing 1 and has a space 2 with a rotating component 3 arranged therein. This is a shaft 3.1 and mounted thereon shaft seal 3.2, which is designed as part of a mechanical seal. In the sectional view, a degassing space 4 attached above the shaft 3.1 and delimited from the space 2 by a subsequently explained element 26 can be seen. The shaft 3.1 held in bearings 5 penetrates a pump cover 6 and carries an impeller 7 of a centrifugal pump 8. Seipumpe befindliches fluid flows along the shaft 3.1 in the space 2 of the degassing.

If there were no degassing device and if there was a gas in space 2 or inside the liquid, the gas would accumulate directly on the rotating component 3 due to the density differences and under the influence of the centrifugal forces. In contrast, the liquid rotates as a liquid ring on a larger diameter around the gas ring around. As a result, the liquid can no longer cool the shaft seal, causing it to be damaged by overheating or failing. For these reasons, a gas must be separated and the space 2 must be completely filled with liquid.

With the help of the degassing device separated gases are accumulated in the degassing 4 and removed therefrom by a closure element 9. This can be done automatically or manually.

Fig. 2 is a section along the line A - A of Fig. 1 and shows a cross section through the degassing. With regard to the axis of rotation 10, dividing wall surfaces are arranged within the space 2, with the aid of which a kind of meander-shaped flow course is achieved until a storage in the degassing space 4 for a gas to be separated out. From the room 2, in which the rotating components 3 are arranged, there is a transition into a vacuum chamber 11 and a degassing space 4 associated therewith. The vacuum chamber 11 and the degassing chamber 4 are indicated by dashed lines.

The axis of rotation 10 of the rotating component 3 lies at the intersection of two orthogonal x and y planes. These limit four spatial quadrants I ₁ II, IM and IV. In the area of the I. spatial quadrant, the vacuum space 11 and its boundaries are arranged. Likewise located therein is a rotation-axis-close rib 12 which, with a free rib end 13, delimits an acceleration gap 14 to the rotating component 3. The direction of rotation of the rotating component 3 is shown by a double arrow on the cut shaft 3.1, on a shaft seal part 3.2 is mounted and rotates with it. Here, above the rib 12 close to the axis of rotation and in the direction of flow behind it, there is the vacuum chamber 11. It is connected via one or more connecting openings 15 to a degassing chamber 4 arranged spatially further away from the axis of rotation 10. The connecting opening 15 can - as shown - be slit-shaped or formed as a perforated wall surface. This is dependent on the forces of the housing to be transmitted 1. The degassing 4 may also be formed as an independent component and connected directly or as a separate element with the space 2 and with the housing 1. A connection between the degasification space 4 and one or more connection openings 15 can take place with the aid of additional known connection means.

FIG. 3 corresponds to FIG. 2 and shows the course of the flows within the housing 1 with the aid of current files. The rotating components 3 cause a drag effect on the liquid in the space 2. The space 2 can be provided as an annular space with the same radius R or, as shown, with a spiral-shaped inner contour 16. Starting from the IV. Quadrant, approximately from the location of the radius R, the spiral contour 16 in the direction of rotation of the rotating component 3 outwardly to the arranged in the spatial I. quadrant rotational axis-near rib 12. This is formed here as part of the cast housing 1 , It can also be designed as a separate component.

The contour of the space 2 is formed in analogy to a spiral housing of a centrifugal pump. Due to the increasing in the circumferential direction cross-sectional area during operation, the static pressure in the space 2 increases slightly and reaches a pronounced maximum pressure in the region of the largest area cross-section at the stagnation point on the pressure side of the axis near-axis rib 12. By the subsequent acceleration of the fluid in the accelerating gap 14 the vacuum chamber 11 imprinted a slight static negative pressure. The static pressure difference between space 2 and vacuum chamber 11 causes a secondary vortex rotating in the vacuum chamber 11 to accumulate with gas. In the vacuum chamber 11, the flow rotates counter to the direction of movement in space 2. The distance between the free end 13 of the rib 12 and the opposite rotating member 3 defines the width of the acceleration gap 14, through which the liquid rotating in the space 2 must flow. As a result, a gap jet 17 forms in and after the acceleration gap 14, which flows away in a tangential direction from the rotating components 3. It is directed to a beam splitter wall surface 18 and is disassembled thereon upon impact. This beam splitting takes place in the region of a projection B of the acceleration slit 14 on the beam splitter wall surface 18 shown in FIG. 3, on the one hand in a secondary or secondary flow which forms a swirl roller 19 in the vacuum chamber 11. And on the other hand into a main flow, which flows in the direction of rotation of the rotating component 3 back into the room 2 and continues to rotate there.

Due to the acceleration of the liquid in the acceleration gap 14, the negative pressure zone 11 forms behind the gap in the vacuum chamber 11, in which an extremely intensive enrichment of the gaseous constituents takes place. A gas-enriched multiphase flow passes from the vacuum space 11 through the connection opening 15 into the degassing space 4. There is the complete outgassing, the removable accumulation of gases and, if necessary, the excretion of gases. The degassing space 4 can also be designed as a separate component and connected via lines with one or more connection openings 15.

For this purpose, the flow in the vacuum chamber 11 is guided in such a way that it follows the course of the beam splitter wall surface 18 and bounces in the region of the inner wall 18.1 of the housing 1 which adjoins the connection opening 15 and also divides the beam. As a result, a smaller partial flow 28 is diverted into the degassing space 4 through the connection opening 15 and along the inner wall 18. 1 of the gas-enriched multiphase mixture rotating in the vacuum space 11. This gas-enriched substream 28 degas there. A gas-free return flow flows along the rear side 29 from the beam splitter wall surface 18 and via the vacuum chamber 11 back into the space 2. This backflow environment flows also follows through the connection opening 15 and this return flow becomes part of the main flow again.

In FIG. 3, the beam splitter wall surface 18 extends at a slight angle of inclination α with respect to the splitting beam 17 impinging thereon. This angle of inclination differs from the normal to the slit beam 17 by about 10 degrees and can be up to 25 degrees. It opens, starting from a limiting edge of the connection opening 15, in the direction of the spatial IV. Quadrant. Thus, a balanced ratio of a flow distribution for the rotating in the main flow within the chamber 2 liquid ring 20 and the rotating in the secondary pressure in the vacuum zone 11 rotating roller 19 is provided.

The angle of inclination α is dependent on the application-finding liquid and its gas content and the rotational speed of the rotating parts 3. In a beam splitter wall surface 18, which is perpendicular to the slit beam 17, the ratio of liquid in the main and secondary flow is approximately equal , The beam splitter wall surface 18 may be formed flat and / or curved, so as to influence the formation of the vortex roll 19 within the vacuum space. This depends on the selected size and an application manufacturing process.

The degassing function also takes place in a concentric with the axis of rotation formed and arranged space 2 in the form of an annular space having a radius R, but accelerates a spiral formation of the peripheral contour of the space 2 the degassing process to a considerable extent.

The limitation for the vacuum chamber 11 is also representable as a kind of separated wall surface of the degassing. In this case, the wall which adjoins the connection opening 15 and carries the beam splitter wall surface 18 is considered as a rib 26 remote from the axis of rotation. Thus, in the space 2 two housing ribs 12, 26 are arranged with opposite direction of extent, which form the vacuum space 11 between them. The ribs are at a distance from each other in opposite directions set direction. Geometric extensions of these ribs 12, 26 in the direction of their free rib ends have no point of intersection.

FIG. 4 shows a section through a vertically arranged degassing device in analogy to the illustration in FIG. 1. In order to ensure a safe function even with such installation positions, a degassing opening 21 is mounted in that end region or corner region of the degassing chamber 4, which is aligned at a later assembly of the degassing upwards. Such a degassing opening 21 can be used for horizontal, diagonal or vertical waves to be arranged 3.1.

In the embodiment, two possible arrangements are shown for this purpose. The degassing opening 21 arranged up here is arranged on a diagonal plane to the axis of rotation. This is done by attaching the vent in an angle to the axis of rotation inclined plane. Thus, both in horizontal and vertical arrangement of the shaft through the opening of the sealing plug degassing occur.

In a reverse arrangement with downwardly facing shaft 3.1, the bottom in the illustrated embodiment degassing would be used. Their radial arrangement in the end region of the degassing space 4 may have the advantage of easier production. For a different installation length of the shaft 3.1, the degassing space 4 would be equipped at each axial end with a degassing opening 21 and a closure element 9.

Fig. 5 shows for a shaft 3.1 with a double seal and a double-formed degassing. The design of their housing ribs and the arrangements of the vacuum zones were carried out analogously to the illustrations of Fig. 2 and 3. The difference is that two degassing devices are arranged in the axial direction one behind the other and consequently the degassing 4 are delimited by a partition wall 22 against each other. Each degassing 4 is provided with vent 21 and stopper 9. The space is in the region of the partition wall level 23 by an insert 24 in two rooms 2.1 and 2.2. divided. This can be done in a uniform Gehäuserohling by simple machining. For the - not visible here - rotation axis-near rib 12 of the room 2.2, this requires a radial shortening in order to mount the insert 24 from the room 2.1. With the help of a simple extension of the rib, the necessary gap width can be set.

In the shaft seals used here in the form of mechanical seals, the stationary housing ring is held in the insert 24. The shaft seal closest to the drive side has a housing-fixed sealing ring, which is held in an insert 25 with a leakage discharge opening.

Fig. 6 shows an embodiment of the degassing device, wherein the same housing of Fig. 5 is equipped with only a single-acting shaft seal. As a result, the machining of the dividing wall 22 in the area of the liquid-carrying space 2 is dispensed with. The two degassing 4 are connected by means of a mounted in the partition wall plane 23 bore 26 and thus converted into a large common degassing 4. About this controllable by a closure element 9 bore 26, the gas removal can take place.

A major advantage of this solution is that it can be easily manufactured as a casting and machining is only necessary in the area of the housing openings for bearing caps, connections or degassing. In addition, a uniform shaft design can be used for two different embodiments.

LIST OF REFERENCE NUMBERS

1 case 29 back side

2, 2.1, 2.2 room

3 rotating component α inclination angle

3.1 wave B projection of the achspa

3.2 shaft seal rallelen gap

4 degassing room

5 bearings

6 pump lids

7 impeller

8 centrifugal pump

9 closure element

10 rotation axis

11 vacuum chamber

12 rotation axis-near rib

13 free rib end

14 acceleration gap

15 connection opening

16 spiral-shaped inner contour

17 slit beam

18, 18.1 Beam splitter wall surface

19 whirl roller

20 liquid ring

21 degassing opening

22 partition wall

23 partition wall level

24 use

25 use with leakage removal

26 rotation axis-distant rib

27 bore

28 partial flow

Claims

Degassing device for liquid-filled rooms with rotating componentsPatent claims

1. Degassing device, consisting of a housing having a space with a rotating component arranged therein, in particular a shaft, a bearing and / or a shaft seal, wherein in space at least one with a free end of the rib to form an axially parallel gap to the ro- tierende component Approaching rib is attached, and that the gap

Degassing space is arranged downstream of a liquid,

characterized,

that in the space (2) at a distance from the gap and the gap opposite a beam splitter wall surface (18) for splitting a slit beam (17) is arranged and that in a lateral distance to a slit projection (B) on the beam splitter wall surface ( 18) is provided with one or more connecting openings (15) for degassing.

2. Degassing device according to claim 1, characterized in that the rib (12) as a rotation axis-near housing rib, forming an acceleration gap (14) close to the rotating component (3).

3. degassing device according to claim 1 or 2, characterized in that the beam splitter wall surface (18) at an angle (α), in particular in the direction of a Normal, to one of the acceleration gap (14) exiting slit beam (17) is arranged.

4. Degassing device according to claim 3, characterized in that a selected inclination of the beam splitter wall surface in the order of an acute angle (α) relative to the normal of the slit beam (17).

5. Degassing device according to claim 1, 2, 3 or 4, characterized in that the beam splitter wall surface (18) is formed as part of a rotation axis-distant housing wall or housing rib (26).

6. Degassing device according to one of claims 1-5, characterized in that the beam splitter wall surface (18) with respect to the rotating component (3) and viewed in cross-section as a passante is formed.

7. Degassing device according to one of claims 1-6, characterized in that the acceleration gap (14) defining the rotation axis-near housing rib (12) and the beam splitter wall surface (18) within a spatial housing quadrant (I.) of the space (2 ) are arranged.

8. Degassing device according to one of claims 1-7, characterized in that free ends of the housing ribs (12, 26) have an opposite direction of extension.

9. Degassing device according to one of claims 1-8, characterized in that in the space (2) between the housing rib (12) and the beam splitter wall surface (18) and on the rotation axis-distant side of the slit jet (17) a vacuum space (11 ) is formed.

10. degassing device according to claim 9, characterized in that the

Vacuum space (11) away from the rotating component (3).

11. Degassing device according to one of claims 1 - 10, characterized in that the rotation axis-distant beam splitter wall surface (18) or provided therewith housing wall or housing rib (26) forms a wall of the degassing space (4).

12. degassing device according to one or more of claims 1-11, characterized in that with respect to the axis of rotation (10) of the vacuum chamber (11) between the axis close to the axis of rotation-axis (12) and the rotation axis-distant degassing space (4) is arranged.

13. Degassing device according to one or more of claims 1 - 12, characterized in that the beam splitter wall surface (18) and / or its in the direction of the connection opening (15) arranged extension on a negative pressure space (11) delimiting beam-dividing inner wall (18.1) stands and that along the beam dividing inner wall (18.1) a partial flow (28) of a

Vacuum space (11) rotating vortex roll (19) flows into the degassing space (4).

14. Degassing device according to one or more of claims 1-13, character- ized in that the degassing space (4) is provided with a degassing opening (21).

15. degassing device according to one or more of claims 1-14, characterized in that two or more degassing in the axial direction are arranged one behind the other and each degassing space (4) with a

Degassing opening (21) is provided.

16. degassing device according to claim 15, characterized in that between two degassing spaces (4.1, 4.2) a partition wall (22) is arranged and in the T-shaped connection region between the partition wall (22) and outer wall a degassing opening (21) is arranged.

17. degassing device according to one or more of claims 1-16, characterized in that at an axial end portion of a degassing space (4, 4.1, 4.2) at an angle to the axis of rotation (10) extending degassing opening (21) is arranged.

18. Degassing device according to one or more of claims 1-17, characterized in that the degassing space (4, 4.1, 4.2) integral or separate part of the housing (1).

19. Degassing device according to one or more of claims 1-18, characterized in that the space surrounding the rotating components (3) space (2), in particular its peripheral wall surface, wholly or partially a helical contour (16).

20. degassing device according to claim 19, characterized in that the rotation tationsachsen-near rib (12) in the spirally developed space of the inner contour (16) in the region of the spatial housing quadrant (I.) is arranged, with respect to the axis of rotation ( 10) has the largest radial extent.