Blade for impeller and methods of making and using the same

Abstract

The present disclosure relates to improved impellers including a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where at least one of 1) the upwardly oriented major surface has concave cross-sectional shape, where the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length; or, 2) where at least one blade includes an arcuate body including a proximal radial edge attached to the hub and a distal radial edge, where the arcuate body defines a camber angle, AC, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, where the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

Description

[0001] BLADE FOR IMPELLER AND METHODS OF MAKING AND USING THE SAME

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to impeller blades for impellers adapted to mix a fluid.

[0004] BACKGROUND ART

[0005] Traditionally, fluid impellers have been utilized in mixing apparatuses to mix liquids, liquid suspensions of solids, and gases contained in vessels. Such impellers have blades that often do not provide a desired mixing efficiency, particularly when used with fluids having complex fluid flow characteristics and in large scale operations. Often, high torque can create instabilities in mixing apparatuses, resulting in high turbulence and mixing time.

[0006] Accordingly, a need exists to develop an impeller blade design which overcomes the drawbacks recited above, namely an impeller blade design with an improved mixing efficiency over traditional impeller blade designs that can be used in a wide array of vessel designs.

[0007] BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments are illustrated by way of example and are not limited in the accompanying figures.

[0009] FIG. 1 includes an exemplary assembly used for mixing using an impeller assembly according to a number of embodiments.

[0010] FIG. 2A illustrates a side view of an embodiment of an impeller according to a number of embodiments.

[0011] FIG. 2B illustrates a top view of an embodiment of an impeller according to a number of embodiments.

[0012] FIG. 2C illustrates a side cross-sectional view of an embodiment of an impeller according to a number of embodiments.

[0013] FIG. 2D illustrates a side cross-sectional view of an embodiment of an impeller according to a number of embodiments.

[0014] FIG. 2E illustrates a side view of another embodiment of an impeller according to a number of embodiments.

[0015] Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0016] The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other embodiments can be used based on the teachings as disclosed in this application.

[0017] The terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0018] Also, the use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one, at least one, or the singular as also including the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in textbooks and other sources within the fluid mixing art.

[0020] Unless otherwise specified, the use of any numbers or ranges when describing a component is approximate and merely illustrative and should not be limited to include only that specific value. Reference to values stated in ranges is intended to include each and every value within that range.

[0021] The following description is directed to embodiments of an impeller blade for an impeller adapted to mix a fluid. One aspect of embodiments of the invention described herein may include an impeller including: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the upwardly oriented major surface has concave cross-sectional shape, where the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0022] One aspect of embodiments of the invention described herein may include an impeller including: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including a proximal radial edge attached to the hub and a distal radial edge, where the arcuate body further includes an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, where the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0023] One aspect of embodiments of the invention described herein may include an assembly including: a vessel containing a fluid; and an impeller configured to mix the fluid, where the impeller includes: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the upwardly oriented major surface has concave cross-sectional shape, where the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0024] One aspect of embodiments of the invention described herein may include an assembly including: a vessel containing a fluid; and an impeller configured to mix the fluid, where the impeller includes: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including a proximal radial edge attached to the hub and a distal radial end, where the arcuate body further includes an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, where the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0025] One aspect of embodiments of the invention described herein may include a method including: providing a vessel containing a fluid; disposing an impeller within the fluid; and mixing the fluid, where the impeller includes: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the upwardly oriented major surface has concave cross-sectional shape, where the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0026] One aspect of embodiments of the invention described herein may include a method including: providing a vessel containing a fluid; disposing an impeller within the fluid; and mixing the fluid, where the impeller includes: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body including a hub and a plurality of blades extending radially outward from the hub, where at least one blade includes an arcuate body including a proximal radial edge attached to the hub and a distal radial end, where the arcuate body further includes an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, where the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, where the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0027] Referring now to the figures, FIG. 1 includes an exemplary assembly used for mixing using an impeller assembly according to a number of embodiments. The mixing assembly 10 may include a vessel 18 having a side 20 that extends from an upper end 22 to an opposing lower end 24. Upper end 22 terminates at an upper end wall 23 while lower end 24 terminates at a lower end wall 34. The vessel 18 also may have an interior surface 26 that bounds a compartment 28. Compartment 28 may be configured to hold a fluid. In the embodiment depicted, vessel 18 may include a flexible, impermeable material such as a low- density polyethylene or other polymeric compositions. Alternatively, the vessel 18 may be a rigid material. The vessel 18 may be made out of any desirable material. For example, the rigid or flexible vessel 18 can contain a polymer, a metal or metallic material, ceramic, glass, or a fibrous material. In particular embodiments, the rigid vessel 18 can include a rigid polymeric material. Further, it is appreciated that vessel 18 can be manufactured to have virtually any desired size, shape, and configuration. For example, vessel 18 can be formed having a compartment sized to 10 liters, 30 liters, 100 liters, 250 liters, 500 liters, 750 liters, 1,000 liters, 1,500 liters, 3,000 liters, 5,000 liters, 10,000 liters or other desired volumes. The size of the vessel 18 can also be in the range between any two of the above volumes.

[0028] Continuing with FIG. 1, in a number of embodiments, the vessel 18 may include a plurality of ports 30 at upper end 22 and a plurality of ports 31 at lower end 24. Each of ports 30, 31 communicate with compartment 28. Although only a few ports 30, 31 are shown, it is appreciated that container 18 can be formed with any desired number of ports 30, 31 and that ports 30, 31 can be formed at any desired location on vessel 18 including along side 20 and on upper end wall 23 and lower end wall 25. Ports 30, 31 can be the same configuration or different configurations and can be used for a variety of different purposes. For example, ports 30, 31 can be coupled with fluid lines for delivering media, cell cultures, gases and / or other components into vessel 18 and also withdrawing gases and fluids from vessel 18.

[0029] Continuing with FIG. 1, in an embodiment, the mixing assembly 10 may include means for delivering a gas into the lower end of vessel 18. By way of example and not by limitation, mixing assembly 10 can include a sparger 34 positioned either on or mounted to lower end 24 of vessel 18 for delivering a gas to the fluid within vessel 18. A gas line 36 may be coupled with sparger 34 for delivering the desired gas to sparger 34. Gas line 36 need not pass through lower end 24 of container 18 but can extend down from upper end 22 or from other locations.

[0030] Continuing with FIG. 1, in an embodiment, mixing assembly 10 may further include an impeller or impeller assembly 40. The impeller or impeller assembly 40 may be detachable or discrete from the vessel 18 and may be a single use impeller 40. In an embodiment, the impeller assembly 40 may include an elongated tubular connector or shaft 44 having a rotational assembly 48 mounted at one end and an impeller 64 mounted on the opposing end down a central axis 1000. The rotational assembly 48 can include a means for rotation of the impeller assembly 40. In a number of embodiments, the rotational assembly 48 can include a drive motor assembly 49 or other means for rotation of an impeller assembly 40 conventionally known in the art. In a number of embodiments, the impeller 64 may rotate clockwise. In a number of embodiments, the impeller 64 may rotate counter-clockwise. More specifically, tubular connector 44 may have a first end 46 and an opposing second end 48 with a passage 51 that extends therebetween. In one embodiment, tubular connector 44 may include a flexible tube such as a polymeric tube. In other embodiments, the tubular connector 44 can include a rigid tube or other tubular structure.

[0031] Continuing with FIG. 1, in a number of embodiments, the impeller 64 can include a body 65 that can be monolithic or in multiple pieces. In a number of embodiments, the body 65 can include central hub 66 oriented down a central axis 1000 and having a plurality of blades 68 radially outwardly projecting therefrom. It is appreciated that a variety of different numbers and configurations of blades 68 can be mounted on hub 66. In a number of embodiments, the hub 66 may have a first end 70 with a socket 72 formed thereat. Socket 72 may have a noncircular transverse cross section, such as polygonal, so that it can engage the tubular connector 44. Impeller 64 can be attached to connector 44 by inserting first end 70 of hub 66 within connector 44 at second end 48. A pull tie, clamp, crimp, or other type of fastener may be cinched around second end 48 of connector 44 so as to form a liquid tight sealed engagement between impeller 64 and connector 44. Accordingly, when the tubular connector 44 is received within socket 72, the rotational assembly 48 engages with the impeller 64 for rotation of the impeller 64.

[0032] In a particular embodiment, the blades 68 can define a mass, FB, with the resultant force oriented substantially parallel with the axis of rotation, AR. The blades 68 can also be adapted to generate a lifting force, FL. In a particular aspect, the blades 68 can be adapted to translate away from the rotatable element 202 when the magnitude of FL reaches a magnitude that is greater than the magnitude of FB.

[0033] In a particular aspect, the blades 68 can be adapted to rotate during operation at a speed of less than 900 revolutions per minute (RPM), such as at a speed of less than 800 RPM, less than 700 RPM, less than 600 RPM, less than 500 RPM, less than 400 RPM, less than 300 RPM, less than 200 RPM, less than 100 RPM, less than 75 RPM, or even less than 65 RPM. The blades 68 can further be adapted to rotate during operation at a speed of at least 10 RPM, such as at least 20 RPM, at least 30 RPM, at least 40 RPM, or even at least 50 RPM.

[0034] In one embodiment, the hub 66 and blades 68 of impeller 64 can be molded using a polymer material. The hub 66 and blades 68 of impeller 64 can also be formed by any other suitable method of construction, including, for example, shaping, bending, extruding, twisting, machining, or a combination thereof. Further, the blades or the impeller can include any suitable material for use in fluidic mixing. For example, the blades may include a polymer material, a metallic material, an epoxy, ceramic, glass, a fibrous material such as wood, or any combination thereof. In a particular embodiment, the hub 66 and blades 68 of impeller 64 can include a polymer layer formed along an outer surface thereof. Exemplary polymers can include a polyketone, polyaramid, a polyimide, a polytherimide, a polyphenylene sulfide, a polyetherslfone, a polysulfone, a polypheylene sulfone, a polyamideimide, ultra high molecular weight polyethylene, a fluoropolymer, a polyamide, a polybenzimidazole, or any combination thereof. In an example, the polymer can include a polyketone, a polyaramid, a polyimide, a polyetherimide, a polyamideimide, a polyphenylene sulfide, a polyphenylene sulfone, a fluoropolymer, a polybenzimidazole, a derivation thereof, or a combination thereof. In a particular example, the thermoplastic material includes a polymer, such as a polyketone, a thermoplastic polyimide, a polyetherimide, a polyphenylene sulfide, a polyether sulfone, a polysulfone, a polyamideimide, a derivative thereof, or a combination thereof. In a further example, the polymer can include a polyketone, such as polyether ether ketone (PEEK), polyether ketone, polyether ketone ketone, polyether ketone ether ketone, a derivative thereof, or a combination thereof. In an additional example, the polymer may be ultra high molecular weight polyethylene. An example fluoropolymer can include a fluorinated ethylene propylene (FEP), a PTFE, a polyvinylidene fluoride (PVDF), a perfluoroalkoxy (PF A), a terpolymer of tetrafluoroethylene, hexafluor opropylene, and vinylidene fluoride (THV), a polychlorotrifluoroethylene (PCTFE), an ethylene tetrafluoroethylene copolymer (ETFE), an ethylene chlorotrifluoroethylene copolymer (ECTFE), or any combination thereof.

[0035] In a particular embodiment, the impeller 64 can include at least 2 blades, such as at least 3 blades, at least 4 blades, at least 5 blades, at least 6 blades, at least 7 blades, at least 8 blades, at least 9 blades, or even at least 10 blades 68. In a further embodiment, the impeller 200 can include no greater than 20 blades, such as no greater than 15 blades, no greater than 10 blades, no greater than 9 blades, no greater than 8 blades, no greater than 7 blades, no greater than 6 blades, no greater than 5 blades, or even no greater than 4 blades 68. In a more preferred embodiment, the impeller 200 can include 4, 5, or even 6 blades 68. At least one blade 68 of the plurality of blades 68 can be staggered around the hub 66 at even increments, e.g., so that the impeller 64 can be rotationally symmetrically.

[0036] In a particular embodiment, at least one of at least one blade 68 of the plurality of blades 68 can have a density that is less than a density of the fluid into which the impeller 64 is to be disposed. In such a manner, at least one blade 68 of the plurality of blades 68 can be more buoyant than the fluid. In an alternative embodiment, at least one blade 68 of the plurality of blades 68 can have a density that is greater than the density of the fluid being mixed. In yet another embodiment, at least one blade 68 of the plurality of blades 68 can have a substantially similar density as the density of the fluid being mixed.

[0037] Turning now to the impeller, FIG. 2A illustrates a side view of an embodiment of an impeller according to a number of embodiments. As stated above, the impeller 200 can generally include a body 265 can be an annular body including a central hub 266 oriented down a central axis 1000 and having a plurality of blades 268 extending radially outward therefrom along the axis of rotation (i.e. central axis 1000). At least one blade 268 of the plurality of blades 268 can extend perpendicular to the hub 266 or at a relative angle thereto, e.g., an angle other than 90 degrees with relation to an outer surface of the hub 266. At least one blade 268 of the plurality of blades 268 may have an arcuate cross-sectional body 270 in a plane perpendicular to the central axis 1000. At least one blade 268 of the plurality of blades 268 may have a substantially rectilinear cross-sectional body 270 in a plane perpendicular to the central axis 1000. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may have an upwardly oriented major surface 272, a downwardly oriented major surface 274, a leading edge 276, and a trailing edge 278. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may be entirely arcuate along at least one or both of its major surfaces 272, 274. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may be entirely rectilinear along at least one or both of its major surfaces 272, 274. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may be entirely arcuate along at least one or both of its leading and trailing edges 276, 278. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may be entirely rectilinear along at least one or both of its leading and trailing edges 276, 278.

[0038] FIG. 2B illustrates a top view of an embodiment of an impeller according to a number of embodiments. In a number of embodiments, the body 270 may further define a proximal radial edge 271 and a distal radial edge 273. As stated above, at least one blade 268 of the plurality of blades 268 may extend radially outward therefrom along the axis of rotation (i.e. central axis 1000) a length, LB, as measured by a longest length of the blade 268 between the proximal radial edge 271 and the distal radial edge 273. The length, LB, can vary between the blades 268, however, in a particular embodiment, the length, LB, is the same between all of the blades 268. The upwardly oriented major surface 272 of at least one blade 268 of the plurality of blades 268 can have a width, WB, as defined by the distance between a leading edge 276 of the blade 268 and a trailing edge 278 of the blade 268, when viewed from a top view. In a particular embodiment, a ratio of LB / WB can be at least 1, such as at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or even at least 10. A blade surface area, SAB, can be defined by the surface area of the major surface 116 of the blade 114 as measured by LB and WB.

[0039] Referring back to FIG. 2A, at least one blade 268 of the plurality of blades 268 can have an average thickness, TB, when viewed in a direction perpendicular to a plane extending radially from the central axis, where TB is no less than about 0.05 cm, no less than about 0.10 cm, no less than about 0.15 cm, or no less than about 0.20 cm. In an embodiment, TB may be no greater than about 0.75 cm, no greater than about 0.50 cm, or no greater than about 0.25 cm. In a particular embodiment, a ratio of WB / TB is at least 2, such as at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or even at least 10.

[0040] Still referring to FIG. 2A, in an embodiment, at least one blade 268 of the plurality of blades 268 can have a non-rectilinear cross-section. For example, at least one of the upwardly oriented major surface 272 or downwardly oriented major surface 274 of the at least one blade 268 of the plurality of blades 268 may be an arcuate or “curved” surface extending between a leading edge 276 and a trailing edge 278. The arcuate surface can be concave or convex relative to the blade 268. In this regard, the arcuate surface can extend outward (i.e., away from) from a tangent line drawn between the leading edge 276 and the trailing edge 278 or can extend inward (i.e., toward) into a tangent line drawn between the leading edge 276 and the trailing edge 278. This arcuate surface can be adapted to generate lifting forces in a fluid and push fluid below by a ram effect, thereby improving circulation below the blades.

[0041] As shown in FIG. 2 A, the upwardly oriented major surface 272 may have a concave cross-sectional shape. This upwardly oriented major surface 272 may have a radius of curvature, Rus, along its circumferential length. In a number of embodiments, the radius of curvature Rus may be positive. In a number of embodiments, the radius of curvature Rus may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature Rus may be negative. In a number of embodiments, the radius of curvature RSF may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than - 100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature Rus may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature Rus may vary along its circumference and radial length.

[0042] As shown in FIG. 2 A, the upwardly oriented major surface 272 may define an angle of upward curvature, Auc. In a number of embodiments, the angle of upward curvature Auc may be positive. In particular embodiments, the angle of upward curvature Auc can be greater than 5 degrees, such as greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees. In further embodiments, the angle of upward curvature Auc can be less than 100 degrees, such as less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees. It will be further appreciated that the angle of upward curvature Auc may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the angle of upward curvature Auc may vary along its circumference and radial length.

[0043] As shown in FIG. 2 A, the downwardly oriented major surface 274 may have a concave cross-sectional shape. This downwardly oriented major surface 274 may have a radius of curvature, RDS, along its circumferential length. In a number of embodiments, the radius of curvature RDS may be positive. In a number of embodiments, the radius of curvature RDS may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature RDS may be negative. In a number of embodiments, the radius of curvature RDS may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than -100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature RDS may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature RDS may vary along its circumference and radial length.

[0044] As shown in FIG. 2A, the leading edge 276 may have an arcuate cross-sectional shape. This leading edge 276 may have a radius of curvature, RLEC, along its circumferential length. In a number of embodiments, the radius of curvature RLEC may be positive. In a number of embodiments, the radius of curvature RLEC may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature RLEC may be negative. In a number of embodiments, the radius of curvature RLEC may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than -100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature RLEC may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature RLEC may vary along its circumference and radial length.

[0045] As shown in FIG. 2A, the leading edge 276 may have an arcuate cross-sectional shape. This leading edge 276 may have a radius of curvature, RLEA, along its axial length. In a number of embodiments, the radius of curvature RLEA may be positive. In a number of embodiments, the radius of curvature RLEA may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature RLEA may be negative. In a number of embodiments, the radius of curvature RLEA may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than -100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature RLEA may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature RLEA may vary along its circumference and radial length.

[0046] As shown in FIG. 2A, the trailing edge 278 may have an arcuate cross-sectional shape. This trailing edge 278 may have a radius of curvature, RTEC, along its circumferential length. In a number of embodiments, the radius of curvature RTEC may be positive. In a number of embodiments, the radius of curvature RTEC may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature RTEC may be negative. In a number of embodiments, the radius of curvature RTEC may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than -100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature RTEC may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature RTEC may vary along its circumference and radial length.

[0047] As shown in FIG. 2A, the trailing edge 278 may have an arcuate cross-sectional shape. This trailing edge 278 may have a radius of curvature, RTEA, along its axial length. In a number of embodiments, the radius of curvature RTEA may be positive. In a number of embodiments, the radius of curvature RTEA may be greater than 0.1 mm, such as greater than 0.5 mm, such as greater than 1 mm, such as greater than 2 mm, such as greater than 5 mm, such as greater than 10 mm, such as greater than 20 mm, such as greater than 25 mm, such as greater than 50 mm, such as greater than 100 mm, such as greater than 200 mm, or such as greater than 500 mm. In a number of embodiments, the radius of curvature RTEA may be negative. In a number of embodiments, the radius of curvature RTEA may be less than -0.1 mm, such as less than -0.5 mm, such as less than -1 mm, such as less than -2 mm, such as less than -5 mm, such as less than -10 mm, such as less than -20 mm, such as less than -25 mm, such as less than -50 mm, such as less than -100 mm, such as less than -200 mm, or such as less than -500 mm. It will be further appreciated that radius of curvature RTEA may be any value between any of the minimum and maximum values noted above. It can also be appreciated that the radius of curvature RTEA may vary along its circumference and radial length.

[0048] FIG. 2C illustrates a side cross-sectional view of an embodiment of an impeller according to a number of embodiments. Referring to FIG. 2C, the non-rectilinear body 270 of the at least one blade 268 of the plurality of blades 268 can have an angle of attack, AA, as defined by the direct angle between the leading edge 276 and the trailing edge 278. The non- rectilinear body 270 of the at least one blade 268 of the plurality of blades 268 can have an angle of attack, AA, as measured by the angle formed between the average major surface and the center axis of rotation of the at least one blade 268 of the plurality of blades 268. In particular embodiments, AA can be at least 20 degrees, such as at least 30 degrees, at least 40 degrees, at least 50 degrees, at least 60 degrees, at least 70 degrees, at least 80 degrees, or even at least 85 degrees. In further embodiments, AA can be no greater than 85 degrees, such as no greater than 80 degrees, no greater than 70 degrees, no greater than 60 degrees, no greater than 50 degrees, or even no greater than 40 degrees. In even more particular embodiments, AA can also be within a range between any of the values described above. It can also be appreciated that AA may vary along its circumference and radial length. In a particular embodiment, the at least one blade 268 of the plurality of blades 268 can have a non-constant angle of attack, AA in a direction radially of the central axis 100 of the blade 268.

[0049] As AA increases, the lift generated by the at least one blade 268 of the plurality of blades 268 can correspondingly increase, generating enhanced lifting characteristics of the at least one blade 268 of the plurality of blades 268 within a fluid. Specifically, as the angle of attack, AA increases from 90 degrees to 135 degrees, the lifting characteristics of the blade 268 can increase. It should be understood that, conversely, as the angle of attack, AA increases from 135 degrees to 180 degrees, the lifting characteristic of the blade 268 can decrease. However, while the lifting characteristic of the at least one blade 268 of the plurality of blades 268 may decrease within a range of between 135 degrees and 180 degrees, the mixing efficiency of the impeller may increase as the relative surface area of the at least one blade 268 of the plurality of blades 268 contacting the fluid increases, thereby increasing the relative force employed by the blade 268 onto the fluid. Thus, in a more particular embodiment, AA can be within a range between and including 105 degrees to 130 degrees. In yet a more particular embodiment, AA can be within a range between and including 115 degrees and 130 degrees.

[0050] FIG. 2D illustrates a side cross-sectional view of an embodiment of an impeller according to a number of embodiments. Referring now to FIG. 2D, the at least one blade 268 of the plurality of blades 268 can also define a camber angle, Ac, as defined by an external angle formed by the intersection of the tangents of the leading edge 276 and the trailing edge 278. In particular embodiments, Ac can be greater than 5 degrees, such as greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees. In further embodiments, Ac can be less than 100 degrees, such as less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees. In even more particular embodiments, Ac can also be within a range between any one of the values described above. It can also be appreciated that Ac may vary along its circumference and radial length. As Ac increases, the lifting forces generated by the at least one blade 268 of the plurality of blades 268 within the fluid can increase. This in turn can generate enhanced mixing efficiency of the fluid.

[0051] FIG. 2E illustrates a side view of another embodiment of an impeller according to a number of embodiments. As stated above, the impeller 200 can generally include a body 265 can be an annular body including a central hub 266 oriented down a central axis 1000 and having a plurality of blades 268 extending radially outward therefrom along the axis of rotation (i.e. central axis 1000). At least one blade 268 of the plurality of blades 268 can extend perpendicular to the hub 266 or at a relative angle thereto, e.g., an angle other than 90 degrees with relation to an outer surface of the hub 266. At least one blade 268 of the plurality of blades 268 may have an arcuate cross-sectional body 270 in a plane perpendicular to the central axis 1000. At least one blade 268 of the plurality of blades 268 may have a substantially rectilinear cross-sectional body 270 in a plane perpendicular to the central axis 1000. In a number of embodiments, the body 270 of the at least one blade 268 of the plurality of blades 268 may have an upwardly oriented major surface 272, a downwardly oriented major surface 274, a leading edge 276, and a trailing edge 278. In a number of embodiments, as described above the body 270 may define a proximal radial edge 271 and a distal radial edge 273.

[0052] As shown in FIG. 2E, the body 270 of the at least one blade 268 may define a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge 276 and the trailing edge 278 as described above. Further, the body 270 of the at least one blade 268 may define a camber angle, ACP, measured at the proximal radial edge 271 and a camber angle, ACD, measured at the distal radial edge 273.

[0053] The camber angle at the proximal radial edge 271, ACP, as defined by an external angle formed by the intersection of the tangents of the leading edge 276 and the trailing edge 278 at the proximal radial edge 271. In particular embodiments, ACP can be greater than 5 degrees, such as greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees. In further embodiments, ACP can be less than 100 degrees, such as less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees.

[0054] The camber angle at the distal radial edge 273, ACD, as defined by an external angle formed by the intersection of the tangents of the leading edge 276 and the trailing edge 278 at the distal radial edge 273. In particular embodiments, ACD can be greater than 5 degrees, such as greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees. In further embodiments, ACD can be less than 100 degrees, such as less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees. In a number of embodiments, ACP may be greater than ACD. In a particular embodiment, a ratio of ACP / ACD is at least 1, such as at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or even at least 10. In a particular embodiment, a ratio of ACP / ACD is no greater than 10, no greater than 9, no greater than 8, no greater than 7, no greater than 6, no greater than 5, no greater than 4, no greater than 3, no greater than 2, no greater than 1. Resultantly, the “twist” in the blade measured by the distance from the trailing edge 278 from an imaginary straight line drawn at 45° is shown. As shown, the angle increases as one traverses the blade from the leading edge 276 to the trailing edge 278, which also increases the distance measured between the blade and the imaginary straight line drawn at 45° as shown.

[0055] In a number of embodiments, using mixing assemblies with impellers having blades according to embodiments herein may function such that turbulent fluid patterns generate within the vessel in improvements over existing impellers. It should be understood that turbulent fluid patterns may increase suspension characteristics of the fluid flow while simultaneously affecting a more homogenous and complete mixing action. Furthermore, when deployed, the larger surface area and changes to the angle of attack, AA, and the camber angle, Ac, can increase mixing efficiency, decrease torque and mixing time, and particularly increase the ability to provide particulate suspension at low RPMs and simultaneously impart a low shear force on the suspended particulate. This in turn can reduce the necessary RPMs (and resulting power number) required to mix a fluid or generate a desirable suspension therein. Correspondingly, by reducing RPMs, the impeller can facilitate equal or even improved mixing characteristics over higher RPM assemblies while imparting a lower shear force to the fluid, which results in lesser homogenization time and lesser torque. This can permit an effective mixing of delicate components, such as, for example, biological organisms or pharmaceuticals, without reducing the effectiveness thereof.

[0056] Further embodiments of the present disclosure are directed to impellers having improved mixing performance, which can be described, for example, as high particle suspension at low RPMs. Such improvement can be seen in both the circulation and, particularly, the ability to maintain particulates in suspension during a mixing operation and prevent the particulates from unwanted agglomeration / clump formation. For example, one type of particulate suspension is cell suspension, which is used in the pharmaceutical and biological industries.

[0057] EXAMPLES

[0058] A study was done aimed at developing the framework for understanding the mixing performance of a top-driven impeller through numerical simulations to estimate the steadystate and homogenization time of the fluids in a vessel. For preliminary simulations a 200 L tank having dimensions 42*38.5*36.25 in / 106.68*97.98*91.77 mm was used with a shaft speed of 90 RPM for comparison of the impellers each having an impeller diameter of approximately 202.64 mm. Since the fluid considered for the simulation is water, which is incompressible, a moving reference frame approach was used where a zone is defined around the moving parts and is rotated around the body’s axis while the body remains still during the simulation phase. In a reference frame that rotates or moves at the same speed as the rotating or moving geometry, governing equations are solved. On a physical level, it means that the flow field around the moving body while seated on it is seen. The flow field becomes stable concerning the geometry as a result. The simulation was done with a conventional straight blade, a curve blade according to embodiments herein (such as the embodiments shown in FIG. 2A), or a twist blade according to embodiments herein (such as the embodiments shown in FIG. 2E). The results of the simulation are shown below in Table 1 :

[0059] Table 1

[0060] As shown in Table 1, homogenization time was lessened with blades for impellers according to embodiments herein over conventional impellers. Further, Power Number, Flow Number, and P / V Ratio were all improved according to embodiments herein over conventional impellers. As a result, the impeller, assembly, or method according to any one of the preceding embodiments may provide a power number of 1 at a speed of 98 RPM and above. As a result, the impeller, assembly, or method according to any one of the preceding embodiments may provide a flow number of 1 at a speed of 98 RPM and above. As a result, the impeller, assembly, or method according to any one of the preceding embodiments may provide a Range of P / V ratio varying from 1 to 2 W / m3for the impeller speed variation of 90 to 120 RPM for the volume of 200 L. Accordingly, P / V ratio will vary for the change in volume of working fluid (e.g. water).

[0061] Many different aspects and embodiments are possible. Some of those aspects and embodiments are described below. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the items as listed below.

[0062] Embodiment 1 : An impeller comprising: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the upwardly oriented major surface has concave cross-sectional shape, wherein the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0063] Embodiment 2: An impeller comprising: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising a proximal radial edge attached to the hub and a distal radial edge, wherein the arcuate body further comprises an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, wherein the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0064] Embodiment 3: A mixing assembly comprising: a vessel containing a fluid; and an impeller configured to mix the fluid, wherein the impeller comprises: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the upwardly oriented major surface has concave cross-sectional shape, wherein the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0065] Embodiment 4: A mixing assembly comprising: a vessel containing a fluid; and an impeller configured to mix the fluid, wherein the impeller comprises: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising a proximal radial edge attached to the hub and a distal radial end, wherein the arcuate body further comprises an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, wherein the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0066] Embodiment 5: A method comprising: providing a vessel containing a fluid; disposing an impeller within the fluid; and mixing the fluid, wherein the impeller comprises: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the upwardly oriented major surface has concave cross-sectional shape, wherein the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0067] Embodiment 6: A method comprising: providing a vessel containing a fluid; disposing an impeller within the fluid; and mixing the fluid, wherein the impeller comprises: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising a proximal radial edge attached to the hub and a distal radial end, wherein the arcuate body further comprises an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, wherein the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

[0068] Embodiment 7: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade as a non-constant angle of attack in a direction radially of the central axis along the blade.

[0069] Embodiment 8: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, Ac, and wherein Ac is greater than 5 degrees, greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees.

[0070] Embodiment 9: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, Ac, and wherein Ac is less than 100 degrees, less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees.

[0071] Embodiment 10: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, ACP, measured at the proximal radial edge, and wherein ACP is greater than 5 degrees, greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees.

[0072] Embodiment 11 : The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, ACP, measured at the proximal radial edge, and wherein ACP is less than 100 degrees, less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees.

[0073] Embodiment 12: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, ACD, measured at the distal radial edge, and wherein ACD is greater than 5 degrees, greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees.

[0074] Embodiment 13: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a camber angle, ACD, measured at the distal radial edge, and wherein ACD is less than 100 degrees, less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees. Embodiment 14: The impeller, assembly, or method according to any one of the preceding embodiments, wherein a ratio of ACP / ACD is at least about 1.1, at least about 1.2, at least about 1.3, at least about 1.4, or even at least about 1.5.

[0075] Embodiment 15: The impeller, assembly, or method according to any one of the preceding embodiments, herein a ratio of ACP / ACD is no greater than about 3.0, no greater than 2.0, no greater than 1.5, or even no greater than 1.25.

[0076] Embodiment 16: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has an angle of attack, AA, measured at the distal radial edge, and wherein AA is greater than 5 degrees, greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees.

[0077] Embodiment 17: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has an angle of attack, AA, measured at the distal radial edge, and wherein AA is less than 100 degrees, less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees.

[0078] Embodiment 18: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has an angle of upward curvature, Auc, measured at the distal radial edge, and wherein Auc is greater than 5 degrees, greater than 10 degrees, greater than 20 degrees, greater than 30 degrees, greater than 40 degrees, greater than 50 degrees, or even greater than 60 degrees.

[0079] Embodiment 19: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has an angle of upward curvature, Auc, measured at the distal radial edge, and wherein Auc is less than 100 degrees, less than 90 degrees, less than 80 degrees, less than 70 degrees, less than 60 degrees, less than 50 degrees, less than 40 degrees, or even less than 30 degrees.

[0080] Embodiment 20: The impeller, assembly, or method according to any one of the preceding embodiments, wherein there are at least 2 blades, at least 3 blades, at least 4 blades, at least 5 blades, at least 6 blades, at least 7 blades, at least 8 blades, at least 9 blades, or even at least 10 blades.

[0081] Embodiment 21 : The impeller, assembly, or method according to any one of the preceding embodiments, wherein there are no greater than 20 blades, no greater than 15 blades, no greater than 10 blades, no greater than 9 blades, no greater than 8 blades, no greater than 7 blades, no greater than 6 blades, no greater than 5 blades, or even no greater than 4 blades.

[0082] Embodiment 22: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has a major surface defined by a width, WB, and a length, LB, and wherein a ratio of LB / WB is at least 2.0, at least 2.5, at least 3.0, at least 3.5, at least 4.0, at least 4.5, or even at least 5.0.

[0083] Embodiment 23 : The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade has an average thickness, TB, and wherein a ratio of WB / TB is at least 2.0, at least 2.5, at least 3.0, at least 4.0, at least 5.0, or even at least 10.0.

[0084] Embodiment 24: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises an average thickness, TB, when viewed in a direction perpendicular to a plane extending radially from the central axis, and wherein TB is no less than about 0.05 cm, no less than about 0.10 cm, no less than about 0.15 cm, or no less than about 0.20 cm.

[0085] Embodiment 25: The impeller, assembly, or method according to embodiment 24, wherein TB is no greater than about 0.75 cm, no greater than about 0.50 cm, or no greater than about 0.25 cm.

[0086] Embodiment 26: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises a monolithic piece.

[0087] Embodiment 27: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises a plurality of pieces.

[0088] Embodiment 28: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises a thermoplastic polymer.

[0089] Embodiment 29: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises a metal.

[0090] Embodiment 30: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade comprises a ceramic.

[0091] Embodiment 31 : The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade is entirely arcuate along both its major surfaces.

[0092] Embodiment 32: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the at least one blade is entirely rectilinear along at least one of its leading edge or its trailing edge. Embodiment 33: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the impeller provides a power number of 1 at a speed of 98 RPM and above.

[0093] Embodiment 34: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the impeller provides a flow number of 1 at a speed of 98 RPM and above.

[0094] Embodiment 35: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the impeller provides a Range of P / V ratio varying from 1 to 2 W / m3for the impeller speed variation of 90 to 120 RPM for the volume of 200 L.

[0095] Embodiment 36: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the downwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

[0096] Embodiment 37: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the leading edge has a radius of curvature of at least 20 mm along its axial length.

[0097] Embodiment 38: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the trailing edge has a radius of curvature of at least 6 mm along its axial length.

[0098] Embodiment 39: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the leading edge has a radius of curvature of at least 400 mm along its radial length.

[0099] Embodiment 40: The impeller, assembly, or method according to any one of the preceding embodiments, wherein the trailing edge has a radius of curvature of at least 600 mm along its radial length.

[0100] Note that not all of the features described above are required, that a portion of a specific feature may not be required, and that one or more features may be provided in addition to those described. Still further, the order in which features are described is not necessarily the order in which the features are installed.

[0101] Certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombinations.

[0102] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the items.

[0103] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination.

[0104] Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or any change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.

Claims

WHAT IS CLAIMED IS:

1. An impeller comprising: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the upwardly oriented major surface has concave cross-sectional shape, wherein the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

2. An impeller comprising: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising a proximal radial edge attached to the hub and a distal radial edge, wherein the arcuate body further comprises an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the arcuate body defines a camber angle, Ac, defined as an external angle formed by the intersection of the tangents of the leading edge and the trailing edge, wherein the camber angle, ACP, measured at the proximal radial edge is greater than the camber angle, ACD, measured at the distal radial edge.

3. A mixing assembly comprising: a vessel containing a fluid; and an impeller configured to mix the fluid, wherein the impeller comprises: a shaft oriented down a central axis and a monolithic annular body attached to the shaft, the annular body comprising a hub and a plurality of blades extending radially outward from the hub, wherein at least one blade comprises an arcuate body comprising an upwardly oriented major surface, a downwardly oriented major surface, a leading edge, and a trailing edge, wherein the upwardly oriented major surface has concave cross-sectional shape, wherein the upwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

4. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has a non-constant angle of attack in a direction radially of the central axis along the blade.

5. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has a camber angle, Ac, and wherein Ac is greater than 5 degrees and less than 100 degrees.

6. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has a camber angle, ACP, measured at the proximal radial edge, and wherein ACP is greater than 5 degrees and less than 100 degrees.

7. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has a camber angle, ACD, measured at the distal radial edge, and wherein ACD is greater than 5 degrees and less than 100 degrees.

8. The impeller, assembly, or method according to any one of the preceding claims, wherein a ratio of ACP / ACD is at least about 1.1 and no greater than about 3.0.

9. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has an angle of attack, AA, measured at the distal radial edge, and wherein AA is greater than 5 degrees and less than 100 degrees.

10. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has an angle of upward curvature, Auc, measured at the distal radial edge, and wherein Auc is greater than 5 degrees and less than 100 degrees.

11. The impeller, assembly, or method according to any one of the preceding claims, wherein there are at least 2 blades and no greater than 20 blades.

12. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has a major surface defined by a width, WB, and a length, LB, and wherein a ratio of LB / WB is at least 2.0.

13. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade has an average thickness, TB, and wherein a ratio of WB / TB is at least 2.0.

14. The impeller, assembly, or method according to any one of the preceding claims, wherein the at least one blade comprises an average thickness, TB, when viewed in a direction perpendicular to a plane extending radially from the central axis, and wherein TB is no less than about 0.05 cm and no greater than about 0.75 cm.

15. The impeller, assembly, or method according to any one of the preceding claims, wherein the downwardly oriented major surface has a radius of curvature of at least 200 mm along its circumferential length.

Images