EP0337394A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for separating gas with a pump from a medium being pumped
Assignee: Ahlstrom Corp
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Filing: 1989-04-11
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Granted: —
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Expires: 2009-04-11
Abstract
Abstract The present invention relates to a method and apparatus for separating gas by a pump from the medium being pumped, which method and apparatus are especially suitable in pumping the gaseous fiber supensions in the wood processing industry. In known apparatus, it has been difficult to prevent solids from entering the gas discharge system fur guiding the gas out of the pump so that the system would clog and give rise to the necessity for expensive and time-consuming reparation. The method and apparatus in accordance with the present invention eliminates or minimizes the above disadvantages in that rear vanes (11) of the pump or the members operating together with them are arranged in such a way that they either direct the flow of the medium, generated by the combined effect of forces with different directions and different intensities directed at the medium in the space behind the impeller in the vane gaps of said rear vanes, past a gas discharge opening (12) in the rear wall of the pump, or they dampen the flow so that its extension to said gas discharge opening (12) is prevented.
Inventors
- 👤 Jorma Elonen
- 👤 Jukka Timperi
- 👤 Reijo Vesala
- 👤 Vesa Wikman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 14:11
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/426; F04D29/428; F04D29/18; F04D29/22; F04D29/2261; F04D29/2288; F04D29/24; F04D29/242; F04D29/245; F04D9/00; F04D9/001; F04D9/002; F04D9/003
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
161 words
A method of separating gas with a pump from a medium being pumped, in which method gas is separated from the medium being pumped to the center of a centrifugal pump on the front side of the impeller, from where gas is discharged through the impeller via the gas discharge openings in the impeller to the back side of the impeller, where the medium possibly flowed with the gas is discharged by means of rear vanes of the impeller from the gas, characterized in that by guiding the flow of the medium, generated by the combined effect of the radial forces, forces parallel with the rim and inertial forces directed at the medium in the space behind the impeller, past the gas discharged duct leading to the gas discharged system or by damping the flow of the medium generated by the combined effect of said forces, the discharge of the medium in said space to the gas discharge system is prevented.
Claim 2
Independent Claim
161 words
A method of separating gas with a pump from a medium being pumped, in which method gas is separated from the medium being pumped to the center of a centrifugal pump on the front side of the impeller, from where gas is discharged through the impeller via the gas discharge openings in the impeller to the back side of the impeller, where the medium possibly flowed with the gas is discharged by means of rear vanes of the impeller from the gas, characterized in that by guiding the flow of the medium, generated by the combined effect of the radial forces, forces parallel with the rim and inertial forces directed at the medium in the space behind the impeller, past the gas discharged duct leading to the gas discharged system or by damping the flow of the medium generated by the combined effect of said forces, the discharge of the medium in said space to the gas discharge system is prevented.
Claim 3
Dependent Claim
92 words
A method in accordance with claim 1, characterized in that the flow, generated by the combined effect the centrifugal forces, forces parallel to the rim, inertial forces and the pressure changes of the guiding apparatus of the pump directed to the medium in the space on the back side of the impeller, which combined effect comprises a radial force component and a force component parallel to the rim, is guided or damped in such a way that the discharge of the medium in said space to the gas discharge system is prevented.
Claim 4
Dependent Claim
63 words
A method in accordance with claim 1, characterized in that the flow directed, due to the combined effect of said forces, along the rear surface of the rear vane of the impeller towards the shaft is allowed to be discharged with the guidance of the force component parallel to the rim to the van gap preceding in the rotational direction of the impeller.
Claim 5
Dependent Claim
56 words
A method in accordance with claim 2, characterized in that the combined effect of said forces is directed in such a way that the flow of the medium generated by said effect is guided past the opening leading to the gas discharge system, whereby the entrance of the medium to the gas discharge system is prevented.
Claim 6
Dependent Claim
53 words
A method in accordance with Claim 1, characterized in that the flow of the medium towards the shaft caused by the combined effect of said forces is guided towards the gas discharged opening in the impeller, from which opening the flow is allowed to be discharged to the front side of the impeller.
Claim 7
Dependent Claim
52 words
A method in accordance with claim 2, characterized in that the entrance of the pressure of the guiding apparatus is prevented to the space on the back side of the impeller, when the pressure of the guiding apparatus is adjacent to its maximum, by throttling said flow passage at the corresponding point.
Claim 8
Dependent Claim
52 words
A method in accordance with claim 2, characterized in tht the entrance of the flow of the medium towards the shaft, generated by the pressure peak of the volute, to the gas discharge system is prevented by throttling the flow passage leading to said system at the pressure peak of the volute.
Claim 9
Dependent Claim
71 words
A method in accordance with claim 2, characterized in that the pressure peak of the volute from accelerating the pulp in said vane gap towards the gas discharge opening leading to the gas discharge system by allowing the discharge of said pressure around the edge of the rear vane of the impeller or via the opening, slot or the like in the rear vane to the vane gap/gaps next to it.
Claim 10
Independent Claim
153 words
An apparatus for separating gas from the medium being pumped by a pump, which comprises a housing (1) with suction and discharge openings (2,3), an impeller (5) arranged inside the housing and provided with pumping vanes (6), rear vanes and gas discharge openings, a rear wall (8) of the pump and means for the discharge of the gas from the pump, characterized in that rear vanes (11; 12; 31, 32; 52, 53) or the members operating together with them have been arranged in such a way that they either direct the flow of the medium, generated by the combined effect of forces with different intensities directed at the medium in the space behind the impeller in the vane gaps of said rear vanes, pas gas discharge opening (12) in the rear wall of the pump or they slow down said flow so that its extension to said gas discharge opening (12) is prevented.
Claim 11
Independent Claim
153 words
An apparatus for separating gas from the medium being pumped by a pump, which comprises a housing (1) with suction and discharge openings (2,3), an impeller (5) arranged inside the housing and provided with pumping vanes (6), rear vanes and gas discharge openings, a rear wall (8) of the pump and means for the discharge of the gas from the pump, characterized in that rear vanes (11; 12; 31, 32; 52, 53) or the members operating together with them have been arranged in such a way that they either direct the flow of the medium, generated by the combined effect of forces with different intensities directed at the medium in the space behind the impeller in the vane gaps of said rear vanes, pas gas discharge opening (12) in the rear wall of the pump or they slow down said flow so that its extension to said gas discharge opening (12) is prevented.
Claim 12
Dependent Claim
117 words
An apparatus in accordance with claim 9, characterized in that rear vanes (11; 21; 31, 32; 52, 53) or the members operating with them have been arranged in such a way that they either direct the flow of the pulp in the vane gaps of said rear vanes being substantially towards the shaft of impeller (5) and mainly caused by the pressure differences of guiding apparatus (15) of the pump past the gas discharge opening (12) in the rear wall of the pump or they damp said flow, in other words the effect of the pressure of the volute of tfe pump in such a way that its extension to the gas discharge opening (12) is prevented.
Claim 13
Dependent Claim
65 words
An apparatus in accordance with claim 9, characterized in that the number z of rear vanes (11; 21; 31, 32; 52, 53) of impeller (5) follows the formula z > 370 * sinβ / n, in which β is the angle between the tangent of the impeller and the average direction of the rear vane, and n is the rotational speed of the impeller r/s.
Claim 14
Dependent Claim
34 words
An apparatus in accordance with claim 9, characterized in that the there are more rear vanes (11; 31, 32; 52, 53) than there are pumping vanes (6) on the front side of impeller (5).
Claim 15
Dependent Claim
73 words
An apparatus in accordance with claim 12, characterized in that there are more rear vanes (11; 31, 32; 52, 53) is at least double the number of actual pumping vanes (6), whereby gas discharge openings (20) of impeller (5) are located, when seen from the back side of the impeller, maximally in every other vane gap depending, of course, on the relation of the number of the rear vanes and pumping vanes (6).
Claim 16
Dependent Claim
22 words
An apparatus in accordance with claim 9, characterized in that rear vanes (21; 31, 32; 52, 53) are inclined forwards or backwards.
Claim 17
Dependent Claim
63 words
An apparatus in accordance with claim 14, characterized in that said rear vanes (21; 31, 32; 52, 53) are inclined from the outer edge substantially backwards relative to the rotational direction of impeller (5) in such a way that the imaginary extension of said rear vanes being the tangent to the central gas discharge opening (12) in the rear wall of the pump.
Claim 18
Dependent Claim
37 words
An apparatus in accordance with claim 12, characterized in that vane (32; 52) preceding gas discharge opening (20) of impeller (5) in the rotational direction of the impeller is shorter than vane (31; 53) following said opening.
Claim 19
Dependent Claim
29 words
An apparatus in accordance with claim 9, characterized in that a flow passage has been arranged in the rear vane of impeller (5) from one vane gap to another.
Claim 20
Dependent Claim
60 words
An apparatus in accordance with claim 17, characterized in that said flow passage is a perforation (56), a gap, a bevel, or a slot (57) in said vane or a flow passage arranged at the rear vanes substantially between the center of the pump and the discharge opening; a cut-out or a duct leading to the area of lower pressure.
Claim 21
Dependent Claim
51 words
An apparatus in accordance with claim 9, characterized in that the inner end of vane (52) preceding gas discharge openings (20) of impeller (5) in the rotational direction of the impeller is arranged to follow in form the front and inner edge of gas discharge opening (20), in other words hook-like.
Claim 22
Dependent Claim
112 words
An apparatus in accordance with claim 9, characterized in that the flow surface area parallel to the rim of the vane gap in gas discharge opening (20) of impeller (5) has been deviated at some point from the conventional form substantially reminding a sector or a bent sector in such a way that it is either uniform through the whole radial length, radially outwards narrowing, throttled by arranging an extension parallel to the rim of the impeller at the end of at least one of the rear vanes, by arranging the rear vanes to be inclined to different directions or by arranging at least one local throttling point in said vane gap.
Claim 23
Dependent Claim
58 words
An apparatus in accordance with claim 9, characterized in that a closing element (50; 51) has been arranged at least between the pressure opening (3) of guiding apparatus (15) of the pump and gas discharge opening (12) in the rear wall of the pump, by which element fiber suspension is prevented from flowing to the gas discharge system.
Claim 24
Dependent Claim
34 words
An apparatus in accordance with claim 21, characterized in that a closing element (50) is mounted in the housing of the pump outside rear vanes (11; 21; 31, 32; 52, 53) of impeller (5).
Claim 25
Dependent Claim
45 words
An apparatus in accordance with claim 21, characterized in that a closing element (50) surrounds completely the rear vanes of impeller (5), whereby openings are arranged in said closing element (50) for the discharge of fiber suspension to the guiding apparatus (15) of the pump.
Claim 26
Dependent Claim
76 words
An apparatus in accordance with claim 21, characterized in that closing element (51) comprises a protrusion parallel to discharge opening (3) of the volute (15) of the pump at the edge of the central gas discharge opening (12) in the rear wall of the pump, which protrusion closes at that point gas discharge opening (12) otherwise surrounding the shaft of impeller (5), in other words it throttles the clearance between the rear wal and the shaft.
Claim 27
Dependent Claim
26 words
An apparatus in accordance with claim 9, characterized in that a vacuum pump has been arranged in communication with the pump in the gas discharge system.
Claim 28
Dependent Claim
38 words
An apparatus in accordance with claim 25, characterized in that a vacuum pump has been arranged on the same shaft with the impeller of the centrifugal pump or it is arranged to be run by a separate motor.
References Cited (Backward Citations)
No citation records indexed.
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