Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2261—Rotors specially for centrifugal pumps with special measures
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/24—Vanes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D1/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2205—Conventional flow pattern
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2261—Rotors specially for centrifugal pumps with special measures
  • F04D29/2272—Rotors specially for centrifugal pumps with special measures for influencing flow or boundary layer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/284—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for compressors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/26—Rotors specially for elastic fluids
  • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
  • F04D29/30—Vanes

Definitions

• the present invention relates to a centrifugal wheel.
• the technical field of the present invention is that of the compression of fluids, liquid or gaseous.
• the invention thus relates to both pumps that compressors that can respectively bring a liquid or a gas, a given pressure at a higher pressure.
• a centrifugal wheel is a wheel having an axis of rotation. It is intended to compress a fluid that flows in a direction parallel to its axis of rotation, the compressed fluid coming out of the wheel in a radially outward direction.
• the element used for this purpose is a fixed part called axial diffuser and which comprises at least one conduit for orienting the compressed fluid.
• the downstream end of the duct that is to say the end opposite the centrifugal wheel, is oriented axially in the orientation that is desired to give the orientation of the compressed fluid.
• the axial diffuser then aims to make a turn about 90 ° to the fluid coming out of the centrifugal wheel to orient it axially.
• Document FR-2 874 241 discloses a high efficiency centrifugal wheel using blades truncated with a radial diffuser.
• the wake of the blade closes in the diffuser and in cooperation with the other wakes of the adjacent blades creates a laminated flow that relaxes gradually in the diffuser.
• We find in this document a wheel incorporating a diffuser.
• the blades, very thick, are located in the lower part of the wheel.
• US-1,447,916 illustrates another embodiment of a wheel incorporating a diffuser.
• the latter may be in one piece with the portion of the wheel having vanes or be a separate piece secured to the portion of the wheel having vanes. It should be noted in all the figures that the vanes illustrated only extend over a part of the device (corresponding to the centrifugal wheel) and not up to the peripheral exit of the device and that the part corresponding to the centrifugal wheel has a perfectly radial outlet upstream of the diffuser.
• a technical problem that we encounter with such a structure is that it is a source of pressure drops for the compressed fluid. It is known that a fluid, when flowing, undergoes pressure losses that depend on the conduit in which it is located and in particular changes of direction that it undergoes.
• An object of the present invention is thus, for a given compression stage, comprising a centrifugal wheel and an axial diffuser, to increase the performance of this stage, that is to say for example for a given power to obtain a rate higher compression or for a given compression being able to limit the mechanical power necessary to exert on the wheel to rotate it.
• the present invention proposes a centrifugal wheel comprising:
• a hub having a longitudinal axis
• a second flange downstream, separated from the first flange by blades thus forming channels each delimited by the first flange, the second flange and two blades and extending from the fluid inlet to a peripheral outlet.
• the first flange has a concave zone oriented towards the channels while the second flange has meanwhile a convex zone oriented towards the channels.
• the passage of a radial flow within the centrifugal wheel to an axial flow in the diffuser downstream of the wheel is made less abruptly to limit the pressure losses when the fluid change of direction.
• the first flange and the second flange advantageously have a form of revolution about the longitudinal axis.
• the surface tangent to the concave zone of the first flange at the outlet of the channel forms an angle of between 1 ° and 45 °, preferably between 10 ° and 30 °, with a radial plane perpendicular to the longitudinal axis.
• the surface tangent to the convex area of the second flange in channel outlet forms an angle of between 1 0 and 45 °, preferably between 10 ° and 30 ° with a radial plane perpendicular to the axis longitudinal.
• the blades extend to the outer peripheral edge of the first flange and / or the second flange.
• the first flange advantageously has an outer peripheral edge adjacent to the channels of diameter greater than that of an outer peripheral edge adjacent to the channels of the second flange.
• the speed is thus higher. This is preferable because the trajectory to be traveled outside a turn is greater than that inside a turn. In this way, a more homogeneous distribution of speed is favored when the fluid then moves according to an essentially longitudinal direction.
• the present invention furthermore relates to a centrifugal compressor and / or a centrifugal pump which comprises a centrifugal wheel as described above.
• FIG. 1 illustrates a centrifugal wheel of the prior art by a sectional view of a half wheel mounted in a compressor
• FIG. 2 is a view similar to that of FIG. 1 for a centrifugal wheel according to a first embodiment according to the present invention
• Fig. 3 is a view similar to the preceding for a second embodiment of the present invention.
• FIG. 4 is a perspective view in section along section line IV-IV of FIG. 2.
• FIG. 1 a centrifugal wheel 2 mounted inside a body 4, for example a compressor body, and on a shaft 6 which has a longitudinal axis 8.
• a body 4 for example a compressor body
• a shaft 6 which has a longitudinal axis 8.
• the following description will be made with reference to a compressor working with air (or more generally gaseous fluids) but the present invention can also be applied to pumps for liquids.
• the centrifugal wheel 2 is made in one piece and comprises a hub 10, a first flange or upstream flange 12, a second flange or downstream flange 14 and vanes 16.
• the hub 10 makes it possible to form a connection between the shaft 6 and the centrifugal wheel 2. It has a circular cylindrical overall cylindrical shape and is provided with means enabling it to be secured to the shaft 6. It is thus conventionally possible, for example, to provide a longitudinal groove in the hub 10 and in the shaft 6 to receive a longitudinal key or splines or any other type of connection.
• the downstream flange 14 is connected directly to the hub 10 and extends radially with respect to the longitudinal axis 8.
• the upstream / downstream orientation is defined relative to the direction of air flow in the centrifugal wheel 2. Indeed , in Figure 1 (as well as in the other figures) the air is sucked to the right of the wheel then moves longitudinally to the left before being driven in a radial direction to be finally oriented, after being out of the wheel centrifuge 2 in a longitudinal direction again to the left of the figure.
• the upstream elements are arranged to the right of the downstream elements in the figures.
• the upstream flange 12 faces the downstream flange 14 and is connected thereto by the blades 16 thus defining channels for air between the two flanges.
• the air is thus conducted between the inner faces of the flanges and the blades in a radial centrifugal manner.
• the upstream flange 12 does not extend to the hub 10 but remains at a distance from it. It has facing the hub 10 a sealing bearing 18 before. Towards the inside of the centrifugal wheel 2, the sealing bearing 18 before defines with the hub 10 an inlet chamber 20 with an annular opening 22 upstream of the inlet chamber 20. To the outside, the bearing sealing ring 18 is machined to make it possible to seal the centrifugal wheel 2 in rotation in the body 4. For example, a seal is used, such as for example a labyrinth ring 24, as interface between the centrifugal wheel 2 and the body 4. As can be seen in the figures, the centrifugal wheel 2 also has on the downstream side another sealing bearing 18, or rear sealing bearing, which extends from the downstream flange 14 and receives another labyrinth ring 24.
• the channels leading the air between the upstream flange 12 and the downstream flange 14 each have an outlet 26 ( Figure 1) oriented radially at the largest diameter of the flanges.
• the air then enters a diffuser 28 in which it is guided in such a way as to have an air flow that is no longer radial but longitudinal.
• Channels 30 in the diffuser 28 also make it possible to transform the helical movement of the air flow into a movement substantially straight.
• FIGS. 2 and 4 illustrate a first embodiment of a centrifugal wheel according to the present invention.
• the overall structure is substantially the same in FIG. 1 and in FIGS. 2 to 4. Therefore, in FIGS. 2 to 4, references in FIG. 1 are used to designate similar elements.
• a centrifugal wheel 2 mounted in rotation in a body 4 about a shaft 6 of longitudinal axis 8, the sealing of the centrifugal wheel 2 relative to the body 4 being ensured in particular by sealing bearings 18 cooperating with labyrinth rings 24 (or other type of seal).
• a hub 10 allows a connection between the wheel and the shaft 6, for example by means of a not shown key.
• the centrifugal wheel 2 further comprises an upstream flange 12 and a downstream flange 14 interconnected by blades 16.
• the upstream flange 12 has a sealing bearing 18 which defines with the hub 10 an inlet chamber 20 for opening 22 annular.
• air or any other fluid
• a diffuser 28 optionally provided with channels.
• outlets 26 are essentially at the outlets 26, that is to say at the region of larger diameter of the upstream flange 12, the downstream flange 14 and blades 16.
• the present invention proposes to provide at the outlet of the centrifugal wheel a flow of air (or other fluid) having an improved velocity vector for enter the longitudinal diffuser.
• a flow of air or other fluid
• it is planned to slightly bend the air channels (defined by the flanges and the blades) in the centrifugal wheel 2 near the outlets 26. This produces a curvature at the outlet of the centrifugal wheel which allows increase the air velocity outward of the curvature.
• the inside face of the upstream flange 12 and the face of the downstream flange 14 are substantially flat (and slightly convergent), the inner face of the upstream flange 12 has near the outlet 26 a concave zone 32 and the inner face of the downstream flange 14 has near the outlet 26, vis-à-vis the concave zone 32, a convex zone 34.
• this surface will be substantially conical (axis cone the longitudinal axis 8) and form with a radial plane illustrated by a line in dotted line an angle a.
• this angle is about 15 ° and is about 30 ° in the embodiment of Figure 3.
• this angle will be between 10 ° and 45 °. In the centrifugal wheels of the prior art, as illustrated in FIG. 1, this angle is substantially zero.
• the surface tangent to the inner face of the upstream flange 12 has not been illustrated.
• FIG. 4 illustrates that the blades 16 extend into the convex zone 34 of the downstream flange 14. Of course, they extend in a similar manner into the concave zone 32 of the upstream flange 12. Preferably, as illustrated in FIG. 4, the blades 16 extend to the peripheral edge of the upstream flange 12 and the downstream flange 14, that is to say to the outlets 26 of the wheel.
• the air is thus accelerated on the upstream side (outside of the "turn" at the exit of the wheel) thus allowing to have a more homogeneous speed at the entrance of a substantially longitudinal section of the diffuser.
• the pressure drops, even if only within the diffuser, are reduced and thus make it possible to increase the efficiency of the device.
• the shape of the centrifugal wheel according to the present invention thus allows a more gradual passage of a radial air flow to a longitudinal flow.
• the distribution of fluid velocities through a passage section of the diffuser is more homogeneous and more regular.
• the pressure losses are thus limited and a gain in terms of efficiency is thus obtained both when the fluid passes from a substantially radial flow to an axial flow and during its flow in the axial diffuser.
• the channels in the centrifugal wheel 2 have a passage in which the flow is substantially radial.
• the inner faces of the upstream flange and the downstream flange each have a curvature inversion.
• the inner face of the upstream flange 12 has a convex zone near the inlet chamber 20 and then away from the hub 10 after an inflection zone, said inner face has a concave zone as described above.
• the inner face of the downstream flange 14 has a concave zone near the inlet chamber 20 and then moving away from the hub 10 after an inflection zone, said inner face has a convex zone as previously described.
• the path of the fluid in the channels defined by the flanges and blades in the centrifugal wheel 2 thus has an inflection.
• the blades 16 extend into the curved zone (that is to say up to the concave zone of the inner face of the upstream flange and up to the convex zone of the inside face of the downstream flange) and guide the fluid preferably to the outlet 26.
• the vanes 16 are thus also curved. They preferably extend from the inlet chamber 20 to the line H and the line S, or for example close to these lines (within 10 mm of these lines).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (9)

Families Citing this family (5)

Citations (3)

Family Cites Families (20)

• 2013
  • 2013-06-18 FR FR1355696A patent/FR3007086B1/fr not_active Expired - Fee Related
• 2014
  • 2014-06-18 EP EP14737288.2A patent/EP3011185B1/de active Active
  • 2014-06-18 JP JP2016520722A patent/JP2016522357A/ja active Pending
  • 2014-06-18 CN CN201480042093.2A patent/CN105518307A/zh active Pending
  • 2014-06-18 KR KR1020167000966A patent/KR20160021229A/ko not_active IP Right Cessation
  • 2014-06-18 RU RU2015154050A patent/RU2015154050A/ru unknown
  • 2014-06-18 US US14/898,239 patent/US20160146215A1/en not_active Abandoned
  • 2014-06-18 WO PCT/FR2014/051512 patent/WO2014202903A1/fr active Application Filing
  • 2014-06-18 CA CA2915720A patent/CA2915720C/en active Active

Patent Citations (3)

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