Patent ID: 12228138

Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present disclosure, the drawings are not necessarily to scale, and certain features may be exaggerated in order to better illustrate and explain the embodiments of the present disclosure.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention.

The invention generally relates to a pump with an impeller comprising a hub having an impelling body, typically surrounded by a sleeve or shroud, in particular for pumping liquids, such as wastewater or other slurries, comprising solids, including fibrous materials.

FIGS.1and2depict a centrifugal non-clog pump1with a pump housing2, an impeller3encased in a pump chamber4of the pump housing2, and a drive shaft5for driving the impeller3. The pump chamber4has an axially directed inlet6at its suction side and a circumferential volute7connecting to a radially directed outlet8at its pressure side. Each of the impeller embodiments disclosed herein can be integrated within a centrifugal non-clog pump, such as, for example, the pump1shown inFIGS.1and2. In some forms, the outlet8can be configured to be tangentially directed from the circumferential volute7. In some forms, the outlet8can be axially directed from the circumferential volute7toward the inlet6or toward the drive shaft5.

FIGS.3A and3Bshow a first embodiment of an impeller103for use with the pump1ofFIGS.1and2. The impeller103inFIGS.3A and3Bincludes an impeller body104comprising a single oblique cone. During operation of the pump, the impeller body104impels the liquid to make it flow from the suction side to the pressure side of the pump1, similar to blades or vanes of vane impellers.

In the Figures the oblique cone is shown as with triangle mesh hatching, but the impeller body104is typically provided as a solid structure with a smooth surface. The impeller103has a circular hub base106at a bottom of the impeller body104. The impeller103also comprises a flaring sleeve or shroud107that is concentric with and spaced apart from the hub base106along a rotational axis X. The impeller103rotates about the rotational axis X during operation.

The impeller body104is provided as an oblique cone along an oblique cone axis C and terminates at an eccentric apex108. The circular hub base106of the impeller body104is concentric with the rotational impeller axis X. The oblique cone axis C crosses the rotational impeller axis X at the center point of hub base106. The impeller body104is adjacent to and surrounded by an interior surface of the sleeve107. The apex108may connect to the interior surface near an upstream edge113of the flaring sleeve107. In this way, the impeller body104and the sleeve107form an integral part and rotate together within the housing2of the pump1during operation.

In an alternative embodiment, the sleeve107can be separate from the impeller body104with a minimized clearance gap between the apex108and the inner surface of the sleeve107. In the separated configuration, the sleeve107is fixed within the housing2of the pump1and the impeller103rotates within the sleeve107. The inner surface of the sleeve107can be smooth, curved, and radially symmetrical in a manner corresponding to the rotational path of the impeller body104about the rotational impeller axis X.

In the embodiment ofFIGS.3A and3B, the flaring sleeve107is trumpet-shaped, having an open upstream end110and an open downstream end111, the open downstream end111facing the hub base106. The open upstream end110provides a fluid pathway and forms an inflow opening in-line with the pump inlet6(shown inFIGS.1A,1B) and is coaxial with the rotational impeller axis X. The sleeve107has a downstream edge112, which defines the downstream open end111. The downstream edge112has a larger diameter than the upstream edge113, which defines the open upstream end110. The downstream edge112of the sleeve107and the circumference of the hub base106define an annular outflow opening114, allowing the impelled liquid to flow into the volute7toward the pump outlet8(shown inFIGS.1A and1B) at the pressure side.

FIGS.4A and4Bshow another embodiment of an impeller203. The impeller203has a rotational axis X about which an impeller body209, provided in the form of an oblique cone, rotates during operation. The impeller body209extends along an oblique cone axis C and has an eccentric apex208. A circular hub base206of the impeller body209is concentric with the rotational impeller axis X, and the oblique cone axis C crosses the rotational impeller axis X at the hub base206at the center point of the hub base206. The impeller body209is surrounded by an inner surface of a sleeve207. In some forms, the apex208connects to the inner surface near an upstream edge213of the flaring sleeve207. In some forms, the apex208is separated from the inner surface by a minimized clearance gap. The sleeve207is trumpet-shaped, having an open upstream end210with an upstream edge213and an open downstream end211with a downstream edge212, the open downstream end211facing the hub base106.

The impeller body209is provided with a vane214that extends from the eccentric apex208to the hub base206and spirals at least partly around the impeller body209. In some forms, the vane214spirals less than 180 degrees around the impeller body. In some forms, the vane214can spiral down from the apex208around the impeller body209at a spiraling angle between 180 and 270 degrees. In some forms, the vane214can spiral down from the apex208around the impeller body209at a spiraling angle greater than 270 degrees. The vane214forms a trailing edge215that can bridge the downstream edge212of the sleeve207and the hub base206. In the shown embodiment, the trailing edge215is parallel to the rotational impeller axis X. One longitudinal side of the vane214may be attached to the inner surface of the sleeve207over its full length, while the other longitudinal side of the vane214may be attached to the surface of the impeller body209over its full length.

In some forms, the vane214is not attached to the inner surface of the sleeve207but is directly adjacent to and slightly offset from the inner surface. In this separated configuration, the sleeve207is fixed within the housing2of the pump1(FIGS.1A,1B) and the impeller203rotates within the sleeve207. In some forms, the vane214is sized and shaped to maintain substantially the same offset distance from the inner surface, along the full length of vane214, over an entire 360 degree rotation of the impeller203. The inner surface of the sleeve207can be smooth, curved, and radially symmetrical in a manner corresponding to the rotational path of the impeller body209about the rotational impeller axis X. The impeller body209and the vane214are shown without the sleeve207inFIG.4B.

FIGS.5A through5Cshow a further exemplary embodiment of an impeller303. The impeller303has an impeller body309and a sleeve307, which is similar to the sleeves107,207of the embodiments disclosed above. A side view and a top plan view of the impeller body309is shown without the sleeve307inFIGS.5B and5C, respectively. The impeller body309is provided in the form of two oblique cones320, which are each shaped similar to the oblique cone shape of impeller bodies104,209in the embodiments ofFIGS.3A and4A. The two cones320share a concentric base and are substantially the same in size and shape. The cones320have oppositely inclined conical axes C, C′. As a result, the impeller body309has two symmetrically arranged eccentric apexes308. The impeller303has a rotational axis X about which the impeller body309rotates during operation. The oblique cone axes C and C′ both cross the rotational impeller axis X at the center point of a hub base306. The circular hub base306of the impeller body309is concentric with the rotational impeller axis X. The oblique cones320are surrounded by an inner surface of the sleeve307. The apexes308can connect to the inner surface near an upstream edge313of the flaring sleeve307.

From each of the eccentric apexes308, a vane314spirals down to the base to form a trailing edge315. In some forms, the trailing edges are arranged on the same plane as the center point of the hub base306. The two vanes314are symmetrically arranged and shaped relative to the rotational impeller axis X. Both vanes314are similar to the vane214of the embodiment shown inFIG.4A. For example, the trailing edges315can bridge a downstream edge312of the sleeve307and the hub base306, and the trailing edges315can spiral at least partly around the corresponding oblique cone320. In some forms, the trailing edges315spiral less than 180 degrees around the impeller body. In some forms, the trailing edges315can spiral down from the apexes308around the impeller body309at a spiraling angle between 180 and 270 degrees. In some forms, the trailing edges315can spiral down from the apexes308around the impeller body309at a spiraling angle greater than 270 degrees. In the shown embodiment, the trailing edge315is parallel to the rotational impeller axis X. One longitudinal side of the vane314can be attached to the inner surface of the sleeve307over its full length, while the other longitudinal side of the vane314is attached to the surface of the impeller body309over its full length.

In some forms, the vane314is not attached to the inner surface of the sleeve307but is directly adjacent to and slightly offset from the inner surface. In this separated configuration, the sleeve307is fixed within the housing2of the pump1(FIGS.1A,1B) and the impeller303rotates within the sleeve307. In some forms, the vanes314are sized and shaped to maintain substantially the same offset distance from the inner surface, along the full length of each vane314, over an entire 360 degree rotation of the impeller303. The inner surface of the sleeve307can be smooth, curved, and radially symmetrical in a manner corresponding to the rotational path of the impeller body309about the rotational impeller axis X.

FIGS.6A and6Bshows a further embodiment of an impeller403, having an impeller body409provided as a single oblique cone420. A ridge415of the impeller body409extends between the surface of the impeller body409and the inner surface of a sleeve407. In this embodiment, the ridge415forms part of the conical surface of the impeller body409and swirls from the apex408down to a downstream edge412of the sleeve407and a hub base411at a point430to form the trailing edge417.

The impeller403has a rotational axis X about which the impeller body409rotates during operation. The circular hub base411of the oblique cone420is concentric with the rotational impeller axis X. The oblique cone420is surrounded by an inner surface of the sleeve407. The apex408can connect to the inner surface near an upstream edge413of the flaring sleeve407. The inner surface of the sleeve407can be shaped to correspond to the ridge415to facilitate connection between the entire length of the ridge415and the inner surface of the sleeve407.

In some forms, the ridge415is not attached to the inner surface of the sleeve407but is directly adjacent to and slightly offset from the inner surface. In this separated configuration, the sleeve407is fixed within the housing2of the pump1(FIGS.1A,1B) and the impeller403rotates within the sleeve407. In some forms, the ridge415is sized and shaped to maintain substantially the same offset distance from the inner surface, along the full length of the ridge415, over an entire 360 degree rotation of the impeller403. The inner surface of the sleeve407can be smooth and radially symmetrical in a manner corresponding to the rotational path of the impeller body409about the rotational impeller axis X.

FIGS.7A-Eshow the impeller body409without the sleeve407. As particularly shown inFIGS.7B and7C, the oblique cone420has an outer slant height417, which can connect to the inner surface of the sleeve407, and an inner slant height418extending between the apex408and a point419on the circumference of the hub base411. The oblique cone420is more particularly dune shaped, the apex408being shaped as a dune crest. The outer slant height417is located on a back side422of the dune, and the inner slant height418is located on a front side424of the dune. On a back side422of the dune, starting near the apex408, the oblique cone420includes an inwardly curved carve-out426that wraps around the oblique cone420and extending all the way down the length of the ridge415. The carve-out426can correspond in size and shape to the inner surface of the trumpet-shaped sleeve407. On the front side424of the oblique cone420, a flute-like groove428spirals from the apex408down the length of the ridge415.

The inner slant height418, the outer slant height417, and the apex408are all coplanar and arranged on a radial plane A (seeFIG.7D). The apex408and the point430are arranged on a plane B, which extends in the direction of axis X. The angle α between plane A and plane B can be an acute, non-zero angle. In some forms, angle α is substantially equal to 50 degrees. Larger or smaller angles between plane A and plane B can also be used, if so desired. During operation of the pump, the impeller rotates in a direction R as indicated inFIG.7D.FIGS.7B and7Care side views from opposite sides parallel to plane A.

FIGS.8A through9Dshow an impeller503having an impeller body509comprising two oblique cones510, similar to the impeller3shown inFIGS.1and2. Also, the oblique cones510are shaped similar to the single oblique cone420of the embodiment shown inFIGS.6A and6B. The two oblique cones510are in diametrically opposite positions on the impeller503and are equally sized but are merged where they cross each other. Each oblique cone510has an outer slant height517, which can connect to the inner surface of a sleeve507, and an inner slant height518extending between an apex508the circumference of a hub base541.

The oblique cones510are dune shaped and each apex508is shaped as a dune crest. The outer slant heights517are located on a back side522of the dune and the inner slant height518is located on a front side524of the dune. Starting near the apexes508, the oblique cones510include inwardly curved carve-outs526that wrap around each of the oblique cones510all the way down the length of ridges515on the back side522of the dune. The carve-out526can correspond in size and shape to the inner surface of the trumpet-shaped sleeve507. On the front side524of each oblique cone510, a flute-like groove528spirals from the apex408down the length of the ridge515. The two oblique cones510share the same concentric hub base541and have eccentric apexes508, which are symmetrically arranged relative to the rotational impeller axis X. The two apexes508are arranged on the same plane as the center point of the hub base541.

Like the impeller403inFIGS.6A and6B, the flaring sleeve507is trumpet-shaped, having a downstream edge512having a larger diameter than an upstream edge544. The downstream edge512of the sleeve507and the circumference of the hub base541define an annular flow opening546. The ridges515can bridge a downstream edge512of the sleeve507and the hub base541. For example, each ridge515can be attached to the inner surface of the sleeve307over its full length.

In some forms, the ridges515are not attached to the inner surface of the sleeve507but are provided directly adjacent to and slightly offset from the inner surface. In this separated configuration, the sleeve507is fixed within the housing2of the pump1(FIGS.1A,1B) and the impeller503rotates within the sleeve507. In some forms, the ridge515is sized and shaped to maintain substantially the same offset distance from the inner surface, along the full length of the ridge515, over an entire 360 degree rotation of the impeller503. The inner surface of the sleeve507can be smooth and radially symmetrical in a manner corresponding to the rotational path of the impeller body409about the rotational impeller axis X.

Both impelling bodies509have a conical surface twisted to form ridges515in the outflow opening546at a distance from the radial plane through the apexes508. The two ridges515are at diametrically opposite positions of the impeller503. The impeller body509is bladeless and vaneless, with the ridges515being formed by a swirling extension of the surface of the respective oblique cone510. During operation of the pump, the impeller rotates in a direction R as shown inFIG.9D.

FIGS.10A and10Bshow an impeller603similar to the impeller503with one structural modification. The impeller603rotates about rotational impeller axis X, includes in impeller body609having two opposing oblique cones620, each oblique cone620having a ridge615that spirals down from an apex608. However, impeller603also includes a dome630formed in the center of the impeller body609where two oblique cones620merge together. The dome630can smooth the edges that are formed by merging the two oblique cones620to form the impeller body609. Also, in some embodiments, the dome630is a removable part that covers a fastener that connects the impeller body609to a drive shaft of a centrifugal non-clog pump, such as pump1(FIGS.1,2).

FIGS.11A through11Dillustrate an impeller703according to a different embodiment. The impeller703has an impeller body703formed as a single oblique cone720. A ridge715of the impeller body409extends between the surface of the impeller body409and the inner surface of a sleeve (not shown). In this embodiment, the ridge715forms part of the conical surface and swirls around the outer circumference of a hub base711. The ridge715maintains substantially the same height as the oblique cone720along its entire length. The impeller703has a rotational axis X about which the impeller body709rotates during operation. The circular hub base711of the oblique cone720is concentric with the rotational impeller axis X.

FIGS.12A through12Cillustrate an impeller803according to one embodiment of the invention. The impeller803has a rotational axis X about which an impeller body809, formed as an oblique cone, rotates during operation. The impeller body809extends along an oblique cone axis C and has an eccentric apex808. A circular hub base806of the impeller body809is concentric with the rotational impeller axis X, and the oblique cone axis C crosses the rotational impeller axis X at the hub base806at the center point of the hub base806. The impeller body809is surrounded by an inner surface of a sleeve807. The sleeve807is trumpet-shaped, having an open upstream end810with an upstream edge813and an open downstream end811with a downstream edge812, the open downstream end811facing the hub base806.

The impeller body809is provided with a vane814extending from the eccentric apex808to the hub base806. The vane814forms a trailing edge815that extends vertically away from the impeller body809. A vane tip830extends away from the apex808along the oblique cone axis C. The vane814can bridge the downstream edge812of the sleeve807and the hub base806. In the shown embodiment, the trailing edge815is parallel to the rotational impeller axis X. One longitudinal side of the vane814can be attached to the inner surface of the sleeve807over its full length, while the other longitudinal side of the vane814is attached to the surface of the impeller body809over its full length.

In some forms, the vane814is not attached to the inner surface of the sleeve807but is directly adjacent to and slightly offset from the inner surface. In this separated configuration, the sleeve807is fixed within the housing2of the pump1(FIGS.1A,1B) and the impeller803rotates within the sleeve807. In some forms, the vane814is sized and shaped to maintain substantially the same offset distance from the inner surface, along the full length of vane814, over an entire 360 degree rotation of the impeller803. The inner surface of the sleeve807can be smooth, curved, and radially symmetrical in a manner corresponding to the rotational path of the impeller body809about the rotational impeller axis X.

EXAMPLE

The following non-limiting example is provided for illustrative purposes only.FIG.13illustrates data collected pursuant to an ISO9906 gr. 2B hydraulic performance test. Impeller A is a prior art impeller, Nijhuis HMFr1-60.70S model L839115, which is a three bladed design, with a diameter of approximately 690 mm, a rotational speed of 745 rpm, and optimized for sewage applications (large free passages and optimized blade leading edges). The test impeller B is an impeller according to the embodiment described above with respect toFIGS.10A and10B.

Impeller A was utilized in a 4x Nijhuis brand VMFAr1-60.70 pump designed for sewage applications. The discharge and suction size of the pump was approximately 610 mm each and the impeller diameter was approximately 690 mm. The speed of the pump was controlled by VFD and had a maximum rpm of 745-750. The flow at the best efficiency point is about 15,000 GPM and the head at the best efficiency point is about 17 meters.

Impeller B was utilized in a 4x Nijhuis brand VMFAr1-60.70 pump designed for sewage applications. The discharge and suction size of the pump was approximately 610 mm each and the impeller diameter was approximately 690 mm. The speed of the pump was controlled by VFD and had a maximum rpm of 745-750. The flow at the best efficiency point is about 15,000 GPM and the head at the best efficiency point is about 17 meters.

The performance of impeller A and impeller B under substantially the same pump conditions was plotted and is depicted inFIG.13. As shown in the graph ofFIG.13, the difference in structure of Impeller B from prior art Impeller A results in improved pump performance. More specifically, it was shown that both the efficiency and the (anti-)clogging performance of impeller B are outstanding and superior to impellers of the prior art. Although not depicted inFIG.13, the impellers of other embodiments were also tested and obtained substantially similar results to that of Impeller B resulting in better efficiency and anti-clogging performance over previously known impellers.

It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. Various features and advantages of the invention are set forth in the following claims.