Title of Invention

"CENTRIFUGAL PUMP WITH CONFIGURED VOLUTE"

Abstract A centrifugal pump of the volute type having a pump casing which has a circular portion extending between a cutwater region and a throat region and a discharge nozzle extending tangentially from the circular portion, and having an impeller positioned within the pump casing and a drive shaft axially connected to the impeller for rotating the impeller within the pump casing, characterized by a contoured volute region (60) formed along the outer periphery of the circular portion (28) of the pump casing extending from the cutwater region (80) to the throat region (82) of the pump casing, the contoured volute region (60) being asymmetrical in axial cross section along the circumference of the pump casing from the cutwater region (80) to the throat region (82), said asymmetry being about a plane which radially bisects the pump casing and volute region (60).
Full Text CENTRIFUGAL PUMP WITH CONFIGURED VOLUTE
BACKGROUND OF THE INVENTION
[0001] Field of the Invention This invention relates to centnfugal pumps used m mdustnal apphcations to process slumes, and specifically relates to centnfugal pumps havmg a volute especially configured to process highly abrasive slurries
[0002] Descnption of Related Art Centnfugal pumps of the volute type are well-knoAvn in the art and have a pump casmg that is generally circular or toroidal m shape The outer penpheral region of the circular pump casmg defines the volute region of the pump The volute region surrounds an impeller positioned withm the pump casmg and is positioned to receive fluids which are processed by the impeller The inner volute region of the pump casmg thus serves as a collector of fluid bemg forced outwardly by the impeller under centnfugal forces
[0003] Typically, the volute region of the pump casing changes m volume as it extends about the circumference of the pump casing That is, the axial cross section of the volute region of the pump casmg taken at any point around the circumference of the pump casmg reveals that the volute has a volume that changes The varymg volume of the volute about the circumference of the pump casmg effects the flow dynamics of the pump as the fluid moves firom the cutwater region of the pump casmg to the discharge nozzle [0004] Additionally, the type of fluids bemg processed by the pump fiirther dictate the selected volume or shape of the volute It is well known that regions of instabihty occur m centnfugal pumps of the volute type Such flow instabilities can cause fluctuations m fluid pressure and can adversely affect pump efficiencies Instabihties m the flow are also known to be caused by the type of fluids bemg pumped (i e, clear water versus slumes) [0005] U S Patent No 5,127,800 to Hyll, et al, descnbes how volute pump design differs between a pump used to process clearwater (i e, flmd that is low m, or essentially devoid of, solids content) and a pump used to process slumes Namely, the impeller of a clear water pump has shrouds the thickness of which is typically comparatively smaller because the fluid, bemg devoid of particulates, does not cause wear on the impeller However, the shrouds of the impeller m a slurry pump are descnbed as bemg thicker to compensate for
degradation of the impeller due the solids content of the fluid The increased thickness of the impeller shrouds results in the development of turbulent flow patterns as the fluid exits the impeller and enters the volute region of the pump The patent to Hyll, et al, therefore discloses a volute that is particularly shaped to compensate for the turbulent flow patterns that result m slurry pumps
[0006] The volute design that is disclosed m the '800 patent to Hyll et al, is selectively configured with arcuate contours the shape or radius of curvature of which vanes about the circumference of the pump casmg Specifically, the volute contour at the cutwater region of the pump, when viewed m axial cross section, compnses a single symmetncal curvature The contour of the volute gradually changes to comprise a tno of connected concave areas the radii of curvature of which change along the circumference of the pump casmg m the direction of the discharge nozzle The cross section configuration of the volute at any pomt along the circumference of the pump casing m the '800 patent is essentially symmetncal about a plane radially bisectmg the volute region [0007] The volute design disclosed m the '800 patent to Hyll, et al, is particularly suited for processing slumes of lower solids content at high flow rates It has been found, however, that while the design of that volute provides stable performance curves, the design is prone to wear by abrasive sohd particles m the pumped slurry This is particularly true m slurry apphcations that are considered "heavy duty" by virtue of the size and coarseness of the solids contamed m the slurry, such as crushed ore slumes [0008] When pumpmg heavy duty slumes, the impeller of the pump must be configured with aggressive expelhng vanes on the front shroud of the impeller (i e, the shroud adjacent the pump inlet) to protect the seal face from abrasive solids More aggressive expelhng vanes operate to create extensive outward onented vortices behmd the expellmg vanes which keep abrasive solid particles m suspension m the volute of the pump and prevent the particles from mfilfrating the seal area The vortices created by aggressive expelhng vanes fransfer additional velocity to the abrasive sohd particles, however, which wears out the convex portions of the contoured volute design disclosed m the '800 patent and degrades the wall surface of the volute
[0009] Thus, it would be beneficial m the art to provide a configured volute for a centnfugal pump that is designed to address the volute degradation encoimtered in the
processing of slurries, particulafly those containing coarse and/or more abrasive solids particulates, while still providing stable performance curves
BRIEF SUMMARY OF THE INVENTION [0010] In accordance with the present invention, the volute region of a -centrifugal pump is configured with an mtenor surface contoured to process fluid -slurries, particularly those containmg coarse and abrasive solids, and to withstand the degradation caused by such slurries thereby providing stable performance curves for the pump. The volute configuration of the present invention can be incorporated into the intenor surface of a pump casmg or can be incorporated as the intenor configuration n of a pump Imer sized to fit within a pump casing
[0011] A centnfiigal pump incorporating the volute configuration of the present mvention generally comprises a circular pump casmg having an impeller positioned within the pump casing The impeller is connected to an axially-onented drive shaft which rotates the impeller within the pump casmg The impeller further comprises at least one impeller blade positioned between spaced apart shrouds, and has at least one discharge operung positioned at the periphery of the impeller for directing flmd toward the volute of the pump casmg The impeller is also structured with at least one e3q)ellmg vane extendmg axiaUy fiom the suction side shroud of the impeller - [0012] The pump casing is typically comprised of a pair of wall portions which when fitted together, enclose the impeller One side of the pump casmg, hereinafter referred to as the dnve side casmg, has an openmg through which the dnve shaft extends to connect to the impeller The opposmg side of the pump casmg, heremafter referred to as the suction side casmg, has an openmg which defines the inlet for fluid flow mto the impeller The mtenor surface of the outer penpheral wall of the conjomed dnve side and suction side pump casmgs defines the volute' In one embodiment of the invention, the pump casing may be configured m accordance with the mvention In an alternative embodiment, the volute configuration of the mvention may be mcorporated mto a liner which is positioned within the pump casmg
[0013] The volute configuration of the present mvention extends along a substantial length of the circumference of the pump casmg or pump Imer between a cutwater region and a throat region that leads mto a discharge .nozzle formed m the pump casing The volute is
configured with a contoured inner surface the shape of which is selected to optimize fliud flow from the impeller into and through the volute of the pump, thereliy providing stable performance curves
J0014J As is known in the art of pumping slurries, the impeller is selected to have a thicker shroud (as compared with the impeller shrouds of a clear water pump) hecausethe impeller is desirably made to -withstand the abrasive effects of the slurry Consequently, the axial width of the impeller opening may be smaller than the axial width of the volute The disparity between those respective widths can result in flow instabihties Thus, the volute of the present invention is contoured to reduce those flow instabihties [0015] Additionally, when pumping heavy duty slurries, the impeller must be configured with aggressive expellmg vanes, located on the suction side shroud of the impeller, to protect the seal face from abrasive sohds More aggressive expellmg vanes operate to create extensive outward oriented vortices behind the expellmg vanes which keep abrasive sohd particles in suspension m the volute region and prevent the particles from infiltratmg the seal area As used herein, aggressive expellmg vanes are those which produce a differential head which is generally not less than about forty percent of the total pump head produced by the impeller vanes The vortices created by aggressive expelhng vanes transfer additional velocity to the abrasive sohd particles which wears out the convex portions of known volute designs Thus, the volute configuration of the present mvention is selected to reduce the degradation caused by those vortices and to prevent degradation of the inner surface of the volute caused by more aggressive slurries
[0016] To achieve the foregomg stated objectives, the volute of the present invention compnses a configured mner surface which is asymmetncal about a radial plane that bisects the pump casmg The volute compnses a first wall that is curved from apomt near the impeller shroud bearmg the expellmg vanes to the outer periphery of the volute and a second wall that is configured with two concave regions havmg disparate radu of curvature The first wall contour defines a collector zone for receivmg fluid from the impeller The concave regions of the second wall respectively define a contiguous portion of the- collector zone and a crrculation zone for channehng the flow exitmg the unpeller openmg mto the collector zone to thereby reduce turbulence m the fluid flow entermg the volute
[0017] The configuration of the axial cross secton of the volute changes from the cutwater of the pump to the throat region near the discharge nozzle of the pump to optimize the flow of slurry entering into and traveling through the volute region to the discharge nozzle The contoured surface of the volute extends to the beginning of the-discharge nozzle of the pump where the inner surface of the discharge nozzle gradually hecomesxircular in axial cross section
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0018] In the drawings, which illustrate what is currently considered to he the hest mode for carrying out the invention
[0019] FIG 1 is an exploded perspective view of apump casing Imer and impeller, [0020] FIG 2 is a view m axial cross section of the pump casmg Imer and impeller of the present mvention taken at hne 2-2 of FIG 4,
[0021] FIG 3 IS a view in axial cross section of a portion .of a pump casmg Imer and impeller of the prior art,
[0022] FIG 4 is a view in elevation of the inner side of the suction side pump casing hner shown m FIG 1,
[0023] FIGS 5 A-5K are views in partial axial cross section of a pump casmg Imer and impeller of the present mvention, as shown m FIG 1, the figures bemg taken at hnes A-A through K-K of FIG 4, and
[0024] FIG 6 IS a partial view m axial cross section of the pump casmg Imer and impeller of the present mvention taken at line K-K of FIG 4, with the contour of the section of the volute taken at Ime H-H supenmposed m phantom thereover
DETAILED DESCRIPTION OF THE INVENTION [0025] The volute configuration of the present mvention is part of a centnfugal pump of the volute type, a pump structure which is well-known m the art Accordmgly, reference is made to US Patent No 5,127,800, the contents of which are mcorporated herem by reference, as lUustratmg the essential elements of a centnfugal pump of the volute type In particular, the centnfugal pump compnses a pump casmg which is typically formed m two clamshell-like halves Each pump casmg half is generally circular and has a tangentially
extending portion definmg a discharge nozzle portion The outer penpheral portion of each casmg half provides a wall portion When the two halves of the pump casmg are joined together and are sealed about their circumference and along the discharge nozzle portion, the penpheral wall portions join to provide a volute region of the pump An impeller is positioned within the pump casmg and is dnven by an axially-onented dnve shaft connected to the impeller The impeller has at least one impeller openmg that is onented toward the volute region of the pump
[0026] FIG 1 illustrates that a centnfugal pump of the volute type may have a pump casmg Imer body 10 sized to be received m the pump casmg The pump casmg Imer body 10, like the pump casmg, may be compnsed of two clamshell-like halves 12, 14 that are sized to nest m the respective halves of a pump casmg It is preferred m most apphcations that a pump casmg Imer be used m the pump smce a punip casmg Imer, once degraded by wear, can be removed and replaced with a new pump casmg Imer The volute configuration of the present mvention is, therefore, descnbed and prmcipally illustrated m terms of bemg mcorporated mto a pump casmg hner of the type shown m FIG 1 However, it is understood that the volute configuration of the present invention may be mcorporated mto the inner surface of the pump casmg itself and is still withm the purview of the mvention
[0027] Refemng agam to FIG 1, one half of the pump casing Imer body 10 may be referred to as the dnve side Imer 12 smce the dnve side Imer 12 is formed wath an opemng 16 through which a portion of the unpeller 20 extends to connect with the dnve shaft (not shown) of a motor The dnve side hner 12 is generally compnsed of a circular portion 22 and a tangentially extending discharge nolzzle portion 24 The other half of the pump casmg liner body 10 may be refened to as the suction side hner 14 since the suction side Imer 12 is formed with an openmg 26 which defines a flmd mlet through which slurry enters into the impeller 20 Like^ase, the suction side hner 14 is generally compnsed of a circular portion 28 and a tangentially extending discharge nozzle portion 30 [0028] When the pump casmg Imer body 10 is positioned m the pump casmg and the halves of the pump casmg are ahgned together, the respective penpheral edges 32, 34 of the dnve side liner 12 and suction side hner 14 come mto registration with each other and seal the impeller 20 withm the pump casing The dnve side Imer 12 of the pump casing
liner body 10 has a wall portion 36 which extends substantially about the circumference of the circular portion 22, and the suction side Imer 14 ias a wall portion 38 which extends substantially about the circumference of ihe circular portion 28 The combination of the respective -wall portions 36,38, -when ihe pump leasing hner body 10 halves are brought together, defines the solute region of thepump as described more fuUy-below. [0029] The impeller 20 that may typically be employed in a centrifugal pump havmg the volute configuration of the present invention is one formed with at least one impeller blade 40 that extends between a first shroud 42 oriented "toward the drive side Imer 12 and a second shroud 44 oriented toward the suction side hner 14 The impeller 20 is formed with a central opemng 46 through which slurry enters into the impeller 20 The slurry contacts the impeller blades 40 and is directed out of the impeller 20 through at least one impeller openmg 48 that is formed adjacent an impeller blade 40 and between the first shroud 42 and second shroud 44 The impeller 20 is further configured with at least one expelhng vane 50 (a plurahty being shown) which extends axially from the surface of the second shroud 44 m the direction of the suction side hner 14
[0030] The elements of the pump casing hner body 10 and impeller 20 are further illustrated m FIG 2, which is an axial cross section view of a pump casmg hner body 10 and impeller 20 as it would appear withm a pump casmg The pump casmg is not shown FIG 2 further illustrates by directional arrows how fluid enters into the impeller 20 through the opemng 46 of the impeller 20 and is directed under centnfiigal forces of the rotating impeller 20 to the volute 60 of the pump The impeller 20 used m processmg heavy duty slurries is structured with a relatively thick first shroud 42 and thick second shroud 44 to withstand the wear and degradation caused by the abrasiveness of the slurry Consequently, the width Wl of the impeller opemng 48 is more narrow than the general width W2 of the volute 60 As is known m the art, the disparity between the width Wl of the impeller openmg 48 and width W2 of the volute 60 produces flow instabilities [0031] Additional effects on pump performance are brought about by the expelling vanes 50 that are mcorporated m the impeller 20 used for processmg heavy duty slumes Expellmg vanes 50 are beneficially used to direct abrasive slurry away from the seal face 62 between the second shroud 44 and the suction side Imer 14 Slurry which infiltrates between the second shroud 44 and suction side hner 14 wears away at the seal face and
degrades both the impeller 20 and liner 14, thereby adversely affectmg pump performance The aggressive expelling vanes 50 of the rtnpeller 20 produce an extensive vortex behind each-expellmg vane 50 which pumps the slurry out and away firom the seal face 62 and keeps the abrasive particles m suspension m the volute 60 However, the vortices produced by the expelhng vanes 50 transfer added velocity to the solids particles which causes degradation of the pump casmg or pump liner inprior art volute configurations [0032] FIG 3 illustrates more clearly how the use of an impeller 20 havmg aggressive expelling vanes 50 causes degradation m a pnor art pump casmg liner L The pump casing Imer L descnbed in the prior art has a volute V which comprises a collection zone C and a recirculation zone R The recirculation zone R further comprises two spaced apart buffer zones B, each of which is defined by a concave region The collection zone C further comprises a concave portion that is separated from the concave regions of the buffer zones B by a convex structure A that extends mwardly toward the impeller 20 It can be seen fi-om FIG 3 that the configuration of the pnor art volute V is substantially symmetncal about a plane P which radially bisects the pump Imer L and volute V The vortices that are produced by the aggressive expelhng vanes 50 produce an mcreased velocity m the particulates of the slurry which stnke the convex structure A of the pnor art pump liner L and degrade it Consequently, rapid matenal erosion results, pump performance suffers and premature failure in service may occur
[0033] Accordingly, the volufe 60 of the present mvention, illustrated m FIGS 2-6, is configured to withstand the mcreased velocities of the slurry particulates and to attam stable flow performance m the pump Referrmg agam to FIG 2, the volute 60 of the present mvention is formed fi'om a first wall portion 36 associated with the dnve side Imer 12 and a second wall portion 38 associated with the suction side Imer 14 The second wall portion 38 is configured with a curved surface 66 which defines at least a portion of a collection region 68 of the volute 60 The collection region 68 receives fluid bemg expelled from the impeller openmg 48 and firom the expelhng vanes 50 The curved surface 66 of the collection region 68 has a radius of curvature which is selected to stabilize fluid flow m the collection region 68
[0034] The volute 60 of the present invention is further foimed fi:om a first wall portion 36 associated with the dnve side Imer 12 of the pump casmg Imer body 10 The first wall
portion 36, along a sigmficant extent of the circumference of the pump casmg Imer body 10, is configured with a first concave region 70 which is contmuous with the curved surface 66 of the second wall portion 38 to complete the collection region 68 of the volute 60 The first wall portion 36, along a sigmficant extent of the circumference of the pump casmg liner body 10, is further configured with a second concave region 72 which defines a circulation zone .74. The iirst concave region 70 and second concave region 72 are separated by -a convex structure 76 therelietween which extends toward the impeller 20 The crrculation zone 74 operates to receive fluid flowing from the impeller opening 48 and redirect it at a modified flow velocity into the collection zone 68, thereby reducing flow turbulence
[0035] It can be appreciated firom the illustration of FIG 2 that the configuration of the volute 60, as viewed m axial cross secbon, changes as the volute 60 contmuously extends about the circumference of the pump casmg liner body 10 The configuration of the volute 60 gradually and continuously changes as the volute 60 extends about the circumference of the pump casmg hner body 10 to optimize the hydraulic mteraction between the impeller and the volute 60 and to provide stable flow performance and efficient pump performance FIG 4 illustrates more clearly that the pump casmg Imer body 10 comprises a circular - portion 28 and a discharge nozzle 30 portion which extends tangentially from the circular portion 28 The volute 60 of the pump casmg hner body 10 extends contmuously along the circumference of the pump casing hner body 10 from a region known as the cutwater 80 to a throat region 82 The throat region 82 contmues mto the discharge nozzle 30 portion of the pump casmg hner body 10 to a terminal end 84 of the discharge nozzle portion 30 Sections designated A-A through K-K of the pump casmg hner body 10 are shown m FIG
4 and correspond to the partial axial cross section views of the volute 60 shown m FIGS
5 A through 5K
[0036] FIG 5 A is a partial axial cross section of the pump casmg hner body 10, impeller and volute 60 at the cutwater 80 (FIG 4) of the pump It can be seen that the curved surface 66 of the suction side Imer 14 has a selected radius of curvature R which is comparatively small m this section of the pump It can also be seen that m this section of the pump, the first concave section 70 is contmuous with the second concave section 72, but the radius of curvature Rl of the first concave section 70 is distmct from the radius of
curvature R2 of the second concave section It is also notable that the configuration of the volute 60 at the cutwater is asyrometncal about a plane 88 which radially bisects the pump casing hner body 10 and volute 60 The plane 88 may be generally defined by the point of joinder of the suction side Imer 14 to the dnve side hner 12
[0037] As the volute 60 contmues smoothly about the circumference of the pump, as shown in FIGS 5B and 5C, the configuration of the volute 60 transitions to a curved surface 66 the radius of curvature R of which is mcreasmg, Also the radius of curvature Rl of the first concave region 70 contmues to mcrease, as does the radius of curvature R2 of the second concave region 72 to form a circulation zone 74 The convex structure 76 which separates the first concave region 70 from the second concave region 72 becomes more pronounced and extends toward the impeller 20
[0038] FIGS 5D through 5H illustrate that as the volute 60 extends further along the circumference of the pump, the collection zone 68 becomes more elongated m a radial direction from the impeller 20 to produce a collection zone 68 of greater volume as compared with the collection zone 68 near the cutwater (FIG 5 A) The radius of curvature R of the curved surface 66 contmues to change, as do the radn of curvature Rl and R2, respectively, of the first concave region 70 and the second concave region 72 As the volute 60 nears the throat region 82 (FIG 4) of the pump, as shown m FIG 5H, the circulation zone 74 begins to compress m radial length as the radial length at the collection zone 68 has increased
[0039] As the volute 60 transitions mto the throat region 82 of the pump, as shown m FIG 51, the configuration of the volute 60 remains asymmetncal about radial plane 88 The circulation zone 74 is reduced m size and the radius of curvature Rl of the first concave region 70 begins to approach the radius of curvature R of the curved surface 66 At a midpomt between the throat region 82 and termmal end 84 of the discharge nozzle portion 30, as illustrated m FIG 5J, the volute 60 smoothly transitions mto the inner surface 90 of the discharge nozzle portion 30 At this pomt, the configuration of the inner surface 90 of the pump casing hner body 10, in axial cross section, is becommg generally circular until, at the termmal end 84 of the discharge nozzle portion 30 shown m FIG 5K, the inner surface 90 is substantially circular [0040] FIG 6 illustrates more clearly the smooth change m the configuration of the volute
60 as the volute 60 approaches the throat region 82 of the pump Shown m axial cross section is the configuration of the volute 60 at Ime I-I of FIG 4 with an outlme of the configuration of the volute 60 configuration at Ime H-H superimposed m phantom thereover It can be seen that as the volute 60 extends circimiferentially toward the discharge nozzle portion 30, the convex structure 76 gradually recedes m prominence until the convex structure 76 disappears at the discharge nozzle portion 30 (FIG 5J) [0041] The configured volute of the present mvention is selected to provide efficient pump performance and stable flow performance m centnfiigal pumps of the volute type when used to process slumes contammg particularly coarse and/or abrasive particulates The configured volute of the present invention is descnbed herem pnncipally with respect to its mcorporation mto the pump casmg Imer of a pump However, the configured volute as descnbed herein may also be mcorporated directly mto a cast or machmed pump casmg which does not employ a liner Further, the exact dimensions of the elements of the volute configuration as descnbed herem may vary as dictated by a particular application or type of slurry being processed Therefore, reference herem to specific details of the volute configurations are by way of example only and not by way of limitation.



We Claims :-
1. A centrifugal pump of the volute type having a pump casing which has a circular portion extending between a cutwater region and a throat region and a discharge nozzle extending tangentially from the circular portion, and having an impeller positioned within the pump casing and a drive shaft axially connected to the impeller for rotating the impeller within the pump casing, characterized by a contoured volute region (60) formed along the outer periphery of the circular portion (28) of the pump casing extending from the cutwater region (80) to the throat region (82) of the pump casing, the contoured volute region (60) being asymmetrical in axial cross section along the circumference of the pump casing from the cutwater region (80) to the throat region (82), said asymmetry being about a plane which radially bisects the pump casing and volute region (60).
2. The centrifugal pump as claimed in claim 1, wherein said contoured volute region comprises a first wall portion having a first concave region having a radius of curvature R1 and a second concave region a radius of curvature Ra, and wherein said contoured volute region comprises a second wall portion having a curved surface which, in combination with said first concave region, defines a collection zone for receiving fluid.
3. The centrifugal pump as claimed in claim 2, wherein said second concave region defines a circulation zone for directing fluid from said impeller to said collection zone.
4. The centrifugal pump as claimed in claim 3, wherein said impeller is configured with at least one aggressive expelling vane positioned proximate said curved surface of said second wall portion.
5. The centrifugal pump as claimed in claim 4, wherein said contoured volute region is formed in the interior peripheral surface of a pump casing liner which is sized to be received in said pump casing.
6. The centrifugal pump as claimed in claim 4, wherein said radius of curvature of said collection zone increases as said contoured volute region extends continuously from said cutwater region of said pump to said throat region of said pump.
7. The centrifugal pump as claimed in claim 1, wherein said contoured volute region is formed in the interior peripheral surface of a pump easing liner sized to be received in said pump casing.
8. The centrifugal pump as claimed in claim 1, wherein said contoured volute region formed along the outer periphery of the circular portion of the pump casing extending from the cutwater region to the throat region of the pump casing is incorporated in a pump casing liner body received in the pump casing of a centrifugal slurry pump having a circular portion and a discharge nozzle extending tangentially from the circular portion, said pump casing liner body having a cutwater region, a throat region and a discharge nozzle portion, and having an inner peripheral surface extending from said cutwater region to said discharge nozzle portion;
a contoured volute located along said inner peripheral surface of said pump casing liner body extending continuously from said cutwater region to said throat region of said pump casing liner body, said contoured volute being asymmetrically configured in axial cross section about a radial plane which bisects said pump casing liner body.
9. The centrifugal pump as claimed in claim 8, wherein said asymmetrically configured volute further comprises a collection zone and a circulation zone positioned to direct fluid into said collection zone, said circulation zone comprising a concave region having a smaller radius of curvature than the radius of curvature of said collection zone.
10. The centrifugal pump as claimed in claim 9, wherein said radius of curvature of said collection zone increases from said cutwater region to said throat region of said asymmetrically configured volute as said contoured volute extends continuously there between.
11. The centrifugal pump as claimed in claim 8, wherein said pump casing liner body further comprises a drive side liner having a peripheral edge and a suction side liner having a peripheral edge which is positioned in registration with said peripheral edge of said drive side liner to provide an enclosure for an impeller, said drive side liner and said suction side liner each having a wall portion the combination of which defines said contoured volute.
12. The centrifugal pump as claimed in claim 11, wherein said wall portion of said suction side liner has a curved surface which defines a portion of a collection zone and, wherein said wall portion of said drive side liner comprises a first concave region which is continuous with said curved surface to define said collection zone and a second concave region which defines a circulation zone.
13. The centrifugal pump as claimed in claim 12, wherein said curved surface has a radius of curvature which increases as said contoured volute extends continuously from said cutwater region to said throat region.
14. The centrifugal pump as claimed in claim 12, wherein said curved surface in said wall portion of said suction side liner is devoid of convexities.
15. The centrifugal pump as claimed in claim 12, wherein said first concave region has a radius of curvature and said second concave region has a radius of curvature, said radius of curvature of said first concave region increasing relative to said radius of curvature of said second concave region as said contoured volute extends continuously from said cutwater region to said throat region.
16. The centrifugal pump as claimed in claim 12, wherein said curved surface of said suction side liner is located for proximate positioning to an expelling vane of an impeller to receive slurry from the expelling vane.
17. The centrifugal pump as claimed in claim 12, wherein said first concave region is separated from said second concave region by a convex structure which extends outward from said wall portion of said drive side liner.
18. The centrifugal pump as claimed in claim 17, wherein said convex structure gradually recedes in prominence as said contoured volute extends continuously toward said throat region.

Documents:

2770-delnp-2005-abstract.pdf

2770-delnp-2005-assignment.pdf

2770-delnp-2005-claims.pdf

2770-delnp-2005-complete specification (as filed).pdf

2770-delnp-2005-complete specification (granted).pdf

2770-DELNP-2005-Correspondence-Others-(12-10-2009).pdf

2770-DELNP-2005-Correspondence-Others-(14-06-2010).pdf

2770-DELNP-2005-Correspondence-Others-(14-09-2010).pdf

2770-delnp-2005-correspondence-others.pdf

2770-delnp-2005-correspondence-po.pdf

2770-delnp-2005-description (complete).pdf

2770-delnp-2005-drawings.pdf

2770-delnp-2005-form-1.pdf

2770-delnp-2005-form-18.pdf

2770-delnp-2005-form-2.pdf

2770-DELNP-2005-Form-3-(12-10-2009).pdf

2770-DELNP-2005-Form-3-(14-06-2010).pdf

2770-DELNP-2005-Form-3-(14-09-2010).pdf

2770-delnp-2005-form-3.pdf

2770-delnp-2005-form-5.pdf

2770-delnp-2005-gpa.pdf

2770-delnp-2005-pct-210.pdf

2770-delnp-2005-pct-304.pdf

2770-delnp-2005-pct-408.pdf

2770-delnp-2005-pct-409.pdf


Patent Number 244273
Indian Patent Application Number 2770/DELNP/2005
PG Journal Number 49/2010
Publication Date 03-Dec-2010
Grant Date 26-Nov-2010
Date of Filing 22-Jun-2005
Name of Patentee WEIR SLURRY GROUP, INC
Applicant Address 2701 SOUTH STOUGHTON ROAD, MADISON, WISCONSIN 53716, U.S.A.
Inventors:
# Inventor's Name Inventor's Address
1 RICARDO AUGUSTO ABARCA MELO HAMBURGO, SANTIAGO, 1655 CHILE.
2 ALEKSANDER S. ROUDNEV 808 BROOK STREET, DE FOREST, WISCONSIN 53532, USA.
3 RONALD J. BOURGEOIS 1296 DOLAN DRIVE, SUN PRAIRIE, WISCONSIN 53590, USA.
PCT International Classification Number F04D 29/44
PCT International Application Number PCT/AU2003/001682
PCT International Filing date 2003-12-17
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/335,584 2002-12-31 U.S.A.