EP2653727B1 - Multistage pump - Google Patents

Multistage pump Download PDF

Info

Publication number
EP2653727B1
EP2653727B1 EP11848993.9A EP11848993A EP2653727B1 EP 2653727 B1 EP2653727 B1 EP 2653727B1 EP 11848993 A EP11848993 A EP 11848993A EP 2653727 B1 EP2653727 B1 EP 2653727B1
Authority
EP
European Patent Office
Prior art keywords
flow path
discharge
discharge flow
casing
region
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Not-in-force
Application number
EP11848993.9A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP2653727A1 (en
EP2653727A4 (en
Inventor
Keisuke Nagaoka
Yasushi Hashimoto
Makoto Noguchi
Daisuke Nakano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kubota Corp
Original Assignee
Kubota Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kubota Corp filed Critical Kubota Corp
Publication of EP2653727A1 publication Critical patent/EP2653727A1/en
Publication of EP2653727A4 publication Critical patent/EP2653727A4/en
Application granted granted Critical
Publication of EP2653727B1 publication Critical patent/EP2653727B1/en
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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
    • F04D1/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F04D1/06—Multi-stage pumps
    • F04D1/063—Multi-stage pumps of the vertically split casing type
    • 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
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/426—Casings; Connections of working fluid for radial or helico-centrifugal pumps especially adapted for liquid 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
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
    • F04D29/44—Fluid-guiding means, e.g. diffusers
    • F04D29/445—Fluid-guiding means, e.g. diffusers especially adapted for liquid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/50—Inlet or outlet
    • F05D2250/52—Outlet

Definitions

  • the present invention relates to a multistage pump such as a single-barreled sectional-type multistage pump.
  • a multistage pump 71 includes a pump casing 72 composed of a plurality of components including a suction opening 73 and a discharge opening 74.
  • the pump casing 72 contains a plurality of impellers 76a to 76c rotated with a rotating shaft 75. Diffusers 77 are provided outside of the outlets of the impellers 76a to 76c.
  • a fluid such as water flows from the suction opening 73 through a suction flow path 78 and is then guided to and raised in pressure by the first-stage impeller 76a.
  • the fluid such as water is guided from the diffuser 77 to the subsequent-stage impeller 76b through an intermediate flow path 79 and is further raised in pressure by the subsequent-stage impeller 76b.
  • the fluid is raised in pressure by the last-stage impeller 76c and is guided from the last-stage diffuser 77 to the discharge opening 74 through a discharge flow path 80.
  • the fluid swirls 35 through the discharge flow path 80 in a swirl direction 82 which is the same as the rotation direction of the impellers 76a to 76c, and is discharged from the discharge opening 74.
  • the discharge flow path 80 is torus-shaped so as to surround the shaft center of the rotating shaft 75 and is partly communicated with the discharge opening 74 via a communication flow path 81 formed in the outward radial direction of the discharge flow path 80.
  • the cross-sectional area of the discharge flow path 80 in a plane including a shaft center 75a of the rotating shaft 75 is constant almost over the periphery other than the communication flow path 81.
  • JP 2005 330878 A describes a multistage pump having a configuration in which a fluid fed to a diffuser from a last-stage impeller is guided to a discharge opening through a discharge flow path.
  • the fluid almost uniformly swirls from the last-stage diffuser 77 along the outer periphery in the swirl direction 82 and then flows in the shaft direction.
  • the fluid swirls through the discharge flow path 80 in the swirl direction 82 while increasing in flow rate and is discharged from the discharge opening 74 through the communication flow path 81.
  • the discharge flow path 80 is shaped like a concentric annulus such that the cross-sectional area of the discharge flow path 80 is constant in the plane including the shaft center 75a of the rotating shaft 75. A portion of the periphery of the discharge flow path 80 is outwardly communicated with the communication flow path 81.
  • a region communicated with the communication flow path 81 in the swirl direction 82 is set as a downstream region 84 while a region opposed to the downstream region 84 is set as an upstream region 83.
  • the cross-sectional area of the discharge flow path 80 is extremely large in the plane including the shaft center 75a, for a small flow rate of the fluid into the discharge flow path 80.
  • the fluid flows through the upstream region 83 of the discharge flow path 80 at a significantly reduced velocity, readily causing stagnation (a dead water region) in the upstream region 83.
  • stagnation a dead water region
  • the substantial uniform flow of the fluid from the last-stage diffuser 77 into the discharge flow path 80 is disturbed in the peripheral direction, disadvantageously resulting in a reduction in pump efficiency.
  • EP 0 618 369 A1 discloses a multistage pump including a pump casing which is provided with a suction opening and a discharge opening and contains a plurality of impellers rotated with a rotating shaft, the multistage pump guiding a fluid raised in pressure by the impeller at a last stage to the discharge opening through a pressure recovery part at the last stage, characterized in that a discharge flow path for guiding the fluid from the pressure recovery part at the last stage to the discharge opening is formed in the pump casing, the discharge flow path is formed in a direction in which the discharge flow path swirls about the shaft center of the rotating shaft, and the cross-sectional area of the discharge flow path in a plane including the shaft center of the rotating shaft increases in the shaft center direction and the inward radial direction of the rotating shaft from the upstream side toward the downstream side of a flow toward the discharge opening.
  • DE 10 2005 060895 A1 shows a multistage pump with a first normal suction pump stage acting as NPSH stage (Net Positive Suction Head) on the suction side and at least one connected self-suctioning channel pump, working with additional fluid.
  • This pump contains a guide wheel which forms an axial spiral, wherein the cross-section of this guide wheel increases continuously and uniformly from the initial cross-section in the flow direction of the fluid to the end cross-section, and the outlet opening of the guide wheel opens into the entry of a first side channel stage without a change of the cross-section.
  • An object of the present invention is to provide a multistage pump which is capable of reducing the size of a pump casing and preventing a reduction in pump efficiency.
  • a first invention is a multistage pump according to claim 1.
  • the fluid sucked into the pump casing through the suction opening is sequentially raised in pressure by the plurality of rotating impellers.
  • the fluid raised in pressure by the last-stage impeller flows through the discharge flow path after the last-stage pressure recovery part and is then discharged from the discharge opening.
  • the fluid flows from the last-stage recovery part into the discharge flow path while swirling and gradually increasing in flow rate from the upstream side toward the downstream side and is discharged from the discharge opening. Meanwhile, the cross-sectional area of the discharge flow path increases from the upstream side toward the downstream side of the flow toward the discharge opening.
  • the flow rate on the upstream side of the discharge flow path is smaller than that on the downstream side. Accordingly, the cross-sectional area of the discharge flow path on the upstream side is smaller than that on the downstream side.
  • This configuration prevents the flow velocity from being significantly reduced on the upstream side of the discharge flow path, thereby preventing the occurrence of stagnation (a water stop region) on the upstream side of the discharge flow path.
  • stagnation a water stop region
  • the cross-sectional area of the discharge flow path increases in the shaft center direction and the inward radial direction of the rotating shaft.
  • the discharge flow path does not expand outwardly in the radial direction, making it possible to reduce the size of the pump casing in the radial direction.
  • the region on the upstream side of the discharge flow path expands more gently in the inward radial direction than the region on the downstream side adjacent to the region on the upstream side. This prevents the flow of the fluid in the inward radial direction from being separated, disturbed, or stagnated in the region on the upstream side of the discharge flow path, further preventing a reduction in pump efficiency.
  • a second invention is the multistage pump, characterized in that the dimension of the cross section of the discharge flow path in the plane including the shaft center of the rotating shaft increases in the shaft center direction at a larger rate in a region on the upstream side of the discharge flow path than in a region on the downstream side adjacent to the region on the upstream side.
  • a third invention is the multistage pump, characterized in that in the upstream region of the discharge flow path, the dimension of the cross section of the discharge flow path increases at a larger rate in the shaft center direction than in the inward radial direction.
  • This configuration can further prevent the flow in the inward radial direction from being separated or disturbed in the region on the upstream side of the discharge flow path, further preventing a reduction in pump efficiency.
  • a fourth invention is the multistage pump, characterized in that the cross-sectional area of the discharge flow path in the plane including the shaft center of the rotating shaft linearly increases from the upstream side toward the downstream side at a predetermined rate.
  • the cross-sectional area of the discharge flow path does not rapidly increase or decrease in a discontinuous manner, thereby reducing an energy loss of the fluid caused by a change of the cross-sectional area and further preventing a reduction in pump efficiency.
  • a fifth invention is the multistage pump, characterized in that the pump casing is partitioned into a suction casing with the suction opening, a discharge casing with the discharge opening, and an intermediate casing interposed between the suction casing and the discharge casing, a fixing member is provided to fasten the casings in the shaft center direction of the rotating shaft, the discharge flow path is formed in the discharge casing, the suction casing includes a suction flow path for guiding the fluid from the suction opening to the inlet of the impeller at a first stage contained in the intermediate casing, the intermediate casing includes an intermediate flow path for guiding the fluid from the outlet of the impeller to the inlet of the impeller at a subsequent stage, the outside diameter of the discharge flow path and the outside diameter of the intermediate flow path are virtually equal, and the fixing member fixes the suction casing and the discharge casing outside of the outside diameters.
  • This configuration prevents the discharge casing from becoming extremely larger than the intermediate casing in the radial direction in the assembly of the pump casing, thereby reducing the size of the pump casing in the radial direction.
  • the present invention can prevent a reduction in the pump efficiency of a multistage pump and achieve a size reduction of the multistage pump.
  • reference numeral 1 denotes a single-barreled sectional-type multistage pump including a pump casing 2 provided with a suction opening 3 and a discharge opening 4.
  • the pump casing 2 contains a plurality of impellers 6a to 6c rotated with a rotating shaft 5.
  • the pump casing 2 is partitioned into a suction casing 7 having the suction opening 3, a discharge casing 8 having the discharge opening 4, and a plurality of sectional-type intermediate casings 9a and 9b placed between the suction casing 7 and the discharge casing 8.
  • the casings 7, 8, 9a, and 9b are fastened and fixed by a fixing member 11 along a shaft center direction A of the rotating shaft 5.
  • the fixing member 11 has a plurality of fixing bolts 12 and nuts 13. Each of the fixing bolts 12 is inserted into the suction casing 7 and the discharge casing 8 located at two ends of the fixing bolt 12 along the shaft center direction A.
  • the nuts 13 are screwed at the two ends of the fixing bolt 12 to fix the suction casing 7 and the discharge casing 8.
  • the rotating shaft 5 is inserted through the pump casing 2 and is sealed by sealing members 15 such as gaskets at shaft seal parts 14.
  • the impellers 6a to 6c are fitted onto the rotating shaft 5 so as to rotate with the rotating shaft 5 and are contained in the intermediate casings 9a and 9b and the discharge casing 8.
  • the impellers 6a to 6c each have an outlet 16 and an inlet 17.
  • the outlet 16 is located outside of the inlet 17 in the radial direction of the rotating shaft 5.
  • a suction flow path 19 is formed in the suction casing 7 to guide water 18 (an example of a fluid) from the suction opening 3 to the inlet 17 of the impeller 6a at the first stage.
  • the suction flow path 19 is torus-shaped so as to surround the rotating shaft 5. This configuration allows the water 18 to flow into the inlet 17 of the impeller 6a as uniformly as possible.
  • the intermediate casings 9a and 9b each have an intermediate flow path 20.
  • the intermediate flow paths 20 guide the water 18 from the outlets 16 of the impellers 6a and 6b to the inlets 17 of the impellers 6b and 6c at the subsequent stages.
  • the intermediate flow paths 20 have toric diffusers 21a and 21b formed outside of the outlets 16 of the impellers 6a and 6b.
  • a toric diffuser 21c (an example of a pressure recovery part) at the last stage and a discharge flow path 22 are provided in the discharge casing 8.
  • the diffuser 21c at the last stage is formed outside of the outlet 16 of the impeller 6c at the last stage.
  • the discharge flow path 22 guides the water 18 having passed through the last-stage diffuser 21c to the discharge opening 4 and is formed spirally in a direction in which the discharge flow path 22 swirls about the shaft center 5a of the rotating shaft 5.
  • a downstream side 22a of the discharge flow path 22 is close to the discharge opening 4 while an upstream side 22b of the discharge flow path 22 is opposite to a flow direction 23 toward the discharge opening 4.
  • the cross-sectional area of the discharge flow path 22 in a plane including a shaft center 5a of the rotating shaft 5 gradually increases from the upstream side 22b toward the downstream side 22a in the shaft center direction A and an inward radial direction B of the rotating shaft 5.
  • the cross-sectional area of the flow path increases toward the rear in the shaft center direction A (that is, from the intermediate casing 9b toward the discharge casing 8).
  • the downstream side 22a of the discharge flow path 22 is positioned behind the upstream side 22b without overlapping the upstream side 22b in the shaft center direction A.
  • the cross-sectional area of the discharge flow path 22 apparently increases in an outward radial direction. This is because a communication path leading to the discharge opening 4 is shown in the drawing.
  • the abscissa indicates positions V1 to V16 along a peripheral direction D of the discharge flow path 22 in FIG. 3 .
  • the positions V1 to V16 are set 22.5° apart from each other along the peripheral direction D.
  • the ordinate in the graph (a) indicates a linear dimension C in the shaft center direction A of the cross section of the discharge flow path in FIG. 9 .
  • the dimension C in the shaft center direction A of the discharge flow path 22 is set to increase at such a rate that a predetermined upstream region 25 including the start position V1 (start point) of the discharge flow path 22 is larger than a predetermined downstream region 26 adjacent to the region 25.
  • the increase rate corresponds to inclinations ⁇ 1 and ⁇ 2 in the graph (a).
  • the inclination ⁇ 1 in the predetermined upstream region 25 (at substantially 180° from the upstream side) is set larger than the inclination ⁇ 2 in the predetermined downstream region 26.
  • the abscissa indicates the positions V1 to V16 along the peripheral direction D of the discharge flow path 22 in FIG. 3
  • the ordinate indicates a linear dimension F from the outside to the inside in the radial direction of the cross section of the discharge flow path 22 in FIG. 9 .
  • the dimension F of the discharge flow path 22 is set to increase in the inward radial direction B at such a rate that a predetermined upstream region 27 including the start position V1 (start point) of the discharge flow path 22 is smaller than a first downstream region 28 adjacent to the region 27.
  • the increase rate corresponds to inclinations ⁇ 1 to ⁇ 3 in the graph (b).
  • the inclination ⁇ 1 in the predetermined upstream region 27 including the start position V1 is set smaller than the inclination ⁇ 2 in the first downstream region 28 adjacent to the region 27. Further, the inclination ⁇ 3 in a second downstream region 29 on the downmost stream side adjacent to the first downstream region 28 is set smaller than the inclination ⁇ 1 in the predetermined upstream region 27. This is because the inclination ⁇ 3 in the second downstream region 29 cannot be set large due to a component, e.g., a balancing disc provided in the inward radial direction B of the discharge flow path 22. In the absence of a component such as a balancing disc, the inclination ⁇ 3 can be set equal to or larger than the inclination ⁇ 2.
  • the increase rate of the dimension C in the shaft center direction A of the discharge flow path 22 (that is, the inclination al in the graph (a) of FIG. 8 ) is larger than that of the dimension F in the inward radial direction B of the discharge flow path 22 (that is, the inclination ⁇ 1 in the graph (b) of FIG. 8 ).
  • an outside diameter G1 of the discharge flow path 22 is kept constant from the start point (the upstream start position V1 in FIG. 3 ) to the flow path communicating with the discharge opening 4 (the downstream position V16 in FIG. 3 ).
  • the outside diameter G1 of the discharge flow path 22 is substantially equal to an outside diameter G2 of the intermediate flow path 20, and an outside diameter G3 of the suction flow path 19 is smaller than the outside diameters G1 and G2.
  • the fixing bolts 12 are located outside of the outside diameters G1 and G2.
  • the impellers 6a to 6c are rotated by a rotation of the rotating shaft 5.
  • the water 18 suctioned from the suction opening 3 into the pump casing 2 flows into the inlet 17 of the first-stage impeller 6a through the suction flow path 19 and flows out of the outlet 16 of the first-stage impeller 6a.
  • the water 18 flows through the intermediate flow path 20 after the first-stage diffuser 21a.
  • the water 18 flows into the inlet 17 and out of the outlet 16 of the subsequent-stage impeller 6b.
  • the water 18 then flows through the intermediate flow path 20 after the subsequent-stage diffuser 21b.
  • the water 18 sequentially raised in pressure thus flows into the inlet 17 and out of the outlet 16 of the last-stage impeller 6c.
  • the water 18 then flows into the discharge flow path 22 through the last-stage diffuser 21c and is discharged from the discharge opening 4.
  • the water 18 is discharged from the discharge opening 4 after being sequentially raised in pressure by the impellers 6a to 6c. At this point, the water 18 uniformly flows into the discharge flow path 22 through the last-stage diffuser 21c in the peripheral direction. The water 18 swirls from the upstream side 22b toward the downstream side 22a of the discharge flow path 22 while gradually increasing in flow rate, and the water 18 is then discharged from the discharge opening 4. Meanwhile, as shown in FIG. 3 , the cross-sectional area of the discharge flow path 22 gradually increases from the upstream side 22b toward the downstream side 22a of the flow toward the discharge opening 4.
  • the flow rate on the upstream side 22b of the discharge flow path 22 is smaller than that on the downstream side 22a.
  • the cross-sectional area of the discharge flow path 22 on the upstream side 22b is smaller than that on the downstream side 22a, thereby suppressing a significant reduction in flow velocity on the upstream side 22b of the discharge flow path 22. This can prevent the stagnation of the water 18 (the flow of the water 18 is disrupted, namely, a dead water region) from occurring on the upstream side 22b of the discharge flow path 22.
  • the flow of the water 18 can be prevented from being greatly disturbed on the upstream side 22b of the discharge flow path 22. Further, the water 18 flows through the discharge flow path 22 from the upstream side 22b toward the downstream side 22a almost uniformly across the cross section of the flow path. This can reduce an energy loss caused by the disturbance of a flow, thereby preventing a reduction in pumping efficiency.
  • the cross-sectional area of the spiral-shaped discharge flow path 22 increases from the upstream side 22b toward the downstream side 22a not in the outward radial direction but in the shaft center direction A and the inward radial direction B of the rotating shaft 5.
  • the discharge flow path 22 does not expand in the outward radial direction, so that the pump casing 2 does not increase in size in the radial direction.
  • the pump casing 2 can be reduced in size in the radial direction.
  • the upstream region 27 of the discharge flow path 22 expands in the inward radial direction B more gradually than the first downstream region 28 adjacent to the region 27. This can particularly prevent the flow of the water 18 close to the inside in the radial direction of the discharge flow path 22 from being separated, disturbed, or stagnated in the upstream region 27 of the discharge flow path 22, further preventing a reduction in pump efficiency.
  • the flow of the water 18 close to the inside in the radial direction of the discharge flow path 22 can be further prevented from being separated or disturbed in the upstream region of the discharge flow path 22, further preventing a reduction in pump efficiency.
  • the pump casing 2 is assembled as follows: the intermediate casings 9a and 9b are interposed between the suction casing 7 and the discharge casing 8; the fixing bolts 12 are inserted into the suction casing 7 and the discharge casing 8; and the nuts 13 are screwed to fix the casings 7, 8, 9a, and 9b.
  • the discharge casing 8 does not become extremely larger than the intermediate casings 9a and 9b in the radial direction, so that the pump casing 2 can be reduced in size in the radial direction.
  • the outside diameter G1 of the discharge flow path 22 and the outside diameter G2 of the intermediate flow path 20 are substantially the same in dimension, which includes the cases where the outside diameters G1 and G2 are totally the same and the outside diameters G1 and G2 are slightly different.
  • the outside diameters G1 and G2 may be considered to be the same in dimension.
  • an outside diameter G1 of a discharge flow path 22, an outside diameter G2 of an intermediate flow path 20, and an outside diameter G3 of a suction flow path 19 are substantially the same in size.
  • the abscissa indicates the positions V1 to V16 along the peripheral direction D of the discharge flow path 22 in FIG. 3
  • the ordinate indicates the cross-sectional area of the discharge flow path 22 in the plane including the shaft center 5a of the rotating shaft 5.
  • the graph shows that the cross-sectional area of the discharge flow path 22 linearly and gradually increases from the start position V1 on the upstream side toward the position V16 on the downstream side at a predetermined rate.
  • the positions V1 to V16 along the peripheral direction D of the discharge flow path 22 are directly proportional to the cross-sectional area of the discharge flow path 22, and the predetermined rate corresponds to an inclination ⁇ in the graph.
  • the cross-sectional area of the discharge flow path 22 linearly and gradually increases from the upstream side toward the downstream side, the cross-sectional area of the discharge flow path 22 does not rapidly increase or decrease in a discontinuous manner. Accordingly, the flow velocity does not vary with a change in the cross-sectional area of the discharge flow path 22, thereby reducing an energy loss of the fluid and further preventing a reduction in pump efficiency.
  • a multistage pump 1 exhibits both the relationship between the positions V1 to V16 and the cross-sectional area of the discharge flow path 22 in the graph of FIG. 11 and the relationships between the positions V1 to V16 and the linear dimensions C and F of the discharge flow path 22 in the graphs of FIGS. 8(a) and 8(b) of the first embodiment.
  • the multistage pump 1 may exhibit only the relationship in the graph of FIG. 11 but may not exhibit the relationships in the graphs of FIGS. 8(a) and 8(b) .
  • the multistage pump 1 includes the three (multiple) impellers 6a to 6c.
  • the number of the impellers is not limited to three. Two or four or more impellers may be provided. Further, the two intermediate casings 9a and 9b are provided but one or three or more intermediate casings may be provided in accordance with the number of the impellers.
  • the sectional-type multistage pump 1 includes the pump casing 2 partitioned into the suction casing 7, the discharge casing 8, and the multiple sectional-type intermediate casings 9a and 9b.
  • the multistage pump 1 may be, for example, a horizontally-partitioned multistage pump including the pump casing 2 partitioned into multiple casings along the cross sections of the pump casing 2 parallel to the shaft center 5a of the rotating shaft 5.
  • the downstream side 22a of the discharge flow path 22 is positioned behind the upstream side 22b without overlapping the upstream side 22b in the shaft center direction A.
  • the downstream side 22a may overlap the upstream side 22b.
  • the cross-sectional area of the discharge flow path 22 gradually increases toward the downstream side 22a.
  • the discharge flow path 22 may have a region in which the cross-sectional area is kept constant, between the upstream side 22b and the downstream side 22a.
  • discharge flow path 22 is formed over a range of substantially 360° but may be formed over a range smaller or larger than 360°.
  • the rate at which the dimensions C and F of the cross section of the discharge flow path 22 increase in FIG. 8 , positions where the increase rate changes, and the number of the changes are not limited to the relationships indicated by the rectilinear graphs.
  • the relationships may be indicated by curvilinear graphs.
  • the inclination ⁇ 1 is smaller than the inclination ⁇ 2.
  • the inclination ⁇ 2 may be smaller than the inclination ⁇ 1, or the inclination ⁇ 2 and the inclination ⁇ 3 may be zero.
  • the dimension F of the cross section of the discharge flow path 22 is kept at a constant value. According to the present invention, the most effective way to prevent a reduction in pump efficiency is to make the inclination ⁇ 1 smaller than the inclination ⁇ 2 as in the graph (b) of FIG. 8 .
  • the multistage pump 1 is illustrated. According to an example which does not form part of the present invention, the same effect as in the multistage pump 1 can be produced in a single-stage pump by increasing the cross-sectional area of the discharge flow path 22 in the shaft center direction A and the inward radial direction B.
  • the diffusers 21a to 21c are used as an example of a pressure recovery part.
  • the diffusers 21a to 21c may be vaned or vaneless.
  • at least one volute may be used.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
EP11848993.9A 2010-12-14 2011-12-13 Multistage pump Not-in-force EP2653727B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2010277557 2010-12-14
JP2011269503A JP5889622B2 (ja) 2010-12-14 2011-12-09 多段ポンプ
PCT/JP2011/078734 WO2012081562A1 (ja) 2010-12-14 2011-12-13 多段ポンプ

Publications (3)

Publication Number Publication Date
EP2653727A1 EP2653727A1 (en) 2013-10-23
EP2653727A4 EP2653727A4 (en) 2017-06-14
EP2653727B1 true EP2653727B1 (en) 2019-09-11

Family

ID=46244661

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11848993.9A Not-in-force EP2653727B1 (en) 2010-12-14 2011-12-13 Multistage pump

Country Status (4)

Country Link
EP (1) EP2653727B1 (zh)
JP (1) JP5889622B2 (zh)
CN (1) CN103261697B (zh)
WO (1) WO2012081562A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019001882A1 (de) * 2019-03-19 2020-09-24 KSB SE & Co. KGaA Mantelgehäusepumpe und Herstellungsverfahren für eine Mantelgehäusepumpe
KR102615546B1 (ko) * 2023-06-28 2023-12-19 윤성업 2축 2속 횡형식 원심 펌프

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2204917B (en) * 1987-05-19 1992-01-08 Apv Uk Centrifugal pump
JPH0788837B2 (ja) * 1988-01-22 1995-09-27 富士電機株式会社 ポンプ
DE4310467A1 (de) * 1993-03-31 1994-10-06 Klein Schanzlin & Becker Ag Topfgehäusepumpe
JP4707969B2 (ja) * 2004-05-19 2011-06-22 株式会社酉島製作所 多段流体機械
JP2006152849A (ja) * 2004-11-26 2006-06-15 Teral Kyokuto Inc 遠心ポンプの吐出ケーシング
DE102005060895B4 (de) * 2005-12-20 2012-07-19 Sero Pumpsystems Gmbh Kreiselpumpe zur Förderung heißer und/oder leicht ausgasender und/oder gasbeladener Medien
CN200940573Y (zh) * 2006-07-31 2007-08-29 上海凯泉泵业（集团）有限公司 一种新型多级泵
CN200975360Y (zh) * 2006-12-04 2007-11-14 上海连成（集团）有限公司 一种带中间轴承的立式多级泵

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
JP2012140931A (ja) 2012-07-26
JP5889622B2 (ja) 2016-03-22
CN103261697B (zh) 2016-01-20
CN103261697A (zh) 2013-08-21
EP2653727A1 (en) 2013-10-23
EP2653727A4 (en) 2017-06-14
WO2012081562A1 (ja) 2012-06-21

Similar Documents

Publication Publication Date Title
US10066638B2 (en) Centrifugal compressor and turbocharger
US8313290B2 (en) Centrifugal compressor having vaneless diffuser and vaneless diffuser thereof
US10119546B2 (en) Rotary machine
US8939720B2 (en) Volute shaped pump casing for a centrifugal pump
US20190285072A1 (en) Centrifugal compressor
US9863427B2 (en) Barrel-type multistage pump
US10138898B2 (en) Centrifugal compressor and turbocharger
EP2653727B1 (en) Multistage pump
KR20070095186A (ko) 원심형 터보기계
US20150354588A1 (en) Centrifugal compressor
JP5727881B2 (ja) 輪切形多段ポンプ
US11187242B2 (en) Multi-stage centrifugal compressor
EP3828417B1 (en) Bridged stage piece
KR102582061B1 (ko) 다단 원심 유체 기계
CN111989495B (zh) 离心压缩机
US9938979B2 (en) Centrifugal pump
US11739766B2 (en) Centrifugal compressor including diffuser pressure equalization feature
JP2003293992A (ja) 多段遠心圧縮機

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20130715

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
RA4 Supplementary search report drawn up and despatched (corrected)

Effective date: 20170515

RIC1 Information provided on ipc code assigned before grant

Ipc: F04D 1/08 20060101AFI20170509BHEP

Ipc: F04D 29/44 20060101ALI20170509BHEP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R079

Ref document number: 602011062060

Country of ref document: DE

Free format text: PREVIOUS MAIN CLASS: F04D0001080000

Ipc: F04D0029420000

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: F04D 29/42 20060101AFI20190523BHEP

Ipc: F04D 29/44 20060101ALI20190523BHEP

Ipc: F04D 1/06 20060101ALI20190523BHEP

INTG Intention to grant announced

Effective date: 20190607

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1178809

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190915

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602011062060

Country of ref document: DE

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20190911

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191211

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191211

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20191212

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1178809

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190911

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200113

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200224

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602011062060

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG2D Information on lapse in contracting state deleted

Ref country code: IS

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20200112

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

26N No opposition filed

Effective date: 20200615

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20191231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191213

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191213

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191231

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191231

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191231

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602011062060

Country of ref document: DE

Representative=s name: PATENTANWAELTE CANZLER & BERGMEIER PARTNERSCHA, DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20111213

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20211102

Year of fee payment: 11

Ref country code: GB

Payment date: 20211028

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190911

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602011062060

Country of ref document: DE

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20221213

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221213

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230701