US2202790A - Waste paper stock pump - Google Patents

Description

May 28, 1940.

F. R. FORREST WASTE PAPER STOCK PUMP Filed Feb. 23, 1938 2 Sheets-Sheet 1 y 1940. F. R. FORREST 2,202,790

WASTE PAPER STOCK PUMP Filed Feb. 23, 1958 2 Sheets-Sheet 2 l atented May 28, 1946 UNITED STATES PATENT OFFICE WASTE PAPER STOCK PUMP Application February 23, 1938, Serial No. 191,879 12 Claims. (01. 103-115) This invention relates in general to improvements in hydraulic machines and more particularly to rotary machines adapted to conduct, without clogging, a flow of fluid containing filamentary material. The invention is more specifically applicable to hydraulic pumps of the type disclosed and claimed. in U. S. Patent No. 1,763,595, F. H. Paatsch, June 10, 1930.

Hydraulic machines of the centrifugal or axial type are frequently utilized to propel a flow of fluid containing filamentary material or to be actuated thereby, but in either case it is necessary to insure that filamentary material may not enter the clearance space between the runner and the casing of the machine to avoid clogging the space between the runner and the casing. The prevention of clogging is generally obtained by utilizing a runner or impeller of the so-called closed type having machined surfaces cooperating with wearing rings in the casing to substantially seal the clearance between the runner and the suction side plate of the casing, and by flushing the clearance with a flow of fluid free from clogging material. It is, however, not possible to use arunner of the closed type when the addition of clearance flushing fluid to the fluid passing through the machine is objectionable. For example, when the fluid is waste paper stock, the addition thereto of flushing water through the pump clearance would thin the stock to an excessive extent. It is then necessary to use an impeller of the so-called open type and to provide means for preventing filamentary material such as string and rubber bands from penetrating into the clearance space between the runner and the casing. In particular, the stationary and movable vanes of the machine must be so shaped that filamentary material impinging thereon is returned into the fluid stream rather than being allowed to drift into the pump clearance. The invention is equally applicable to hydraulic turbines and to hydraulic pumps.

It is therefore one of the objects of the present invention to provide a rotary hydraulic machine, either motor or pump, adapted to conduct, without clogging, a fluid stream containing filamentary material. I Another object of the present invention is to provide a rotary hydraulic machine adapted to conduct a fluid stream containing filamentary material and which does not require any means for removing material from the clearance space between the machine casing and runner.

Another object of the present invention is to provide a rotary hydraulic machine adapted to conduct a fluid stream containing filamentary material in which filamentary material imping-' ing on a movable or stationary vane is returned into the fluid stream.

Another object of the present invention is to 5 provide a rotary hydraulic machine adapted to conduct a fluid stream containing filamentary material in which filamentary material impinging on the vanes of a runner is prevented from penetrating into the clearance space between the runner and the casing.

Objects and advantages other than those above described will be apparent from the following description. when read in connection with the accompanying drawings, in which:

Fig. l is a View partially in axial cross section through and partially in elevation of a centrifugal pump forming an embodiment of the present invention;

Fig. 2 is an end view of the runner of the pump illustrated in Fig. 1.

Fig. 3 is an enlarged fragmentary view in perspective of the inlet edge of the runner illustrated in Figs. 1 and 2;

Fig. 4 is a fragmentary end View of a modified embodiment of the pump runner;

Fig. 5 is a View in cross section taken on plane V-V in Fig. 4;

Fig. 6 is an axial cross section through a pump of the axial flow type forming another embodiment of the present invention; and

Fig. 7 is a view in perspective of the runner of the pump illustrated in Fig. 6.

Referring more particularly to the drawings by characters of reference, reference numeral ll designates a split casing forming a housing for an open type runner or impeller 12 mounted for rotation therein. The runner is fastened on a shaft l3 supported in any suitable bearing (not shown) and connected with a suitable driving means (not shown). The shaft extends into the pump casing through a stuffing box containing a packing l4. Leakage of fluid from the pump casing through the stufling box is prevented by introducing clear water or other sealing fluid 45 under pressure at an intermediate point of the stuffing box where some of the packing material is replaced by a so-called lantern or water seal ring 16. Casing I I is provided at one end thereof with a tubular extension which forms a suction passage l1 and which is adapted to be bolted or otherwise fastened to the suction piping (not shown) conducting the fluid stream to the pump. Access may be obtained to the suction passage through a hand hole provided with a cover I8 carrying a bafiie or guide vane i 9. The peripheral portion of casing forms a spiral discharge passage 2| adapted to lead the fluid passing through the pump to discharge piping (not shown). The intermediate portion of casing preferably comprises a pair of removable side plates 22, 23 held therein by tongue and groove annular joints and shaped to conform to the structure of the impeller with the least possible clearance. The suction side plate 22 is provided with an inwardly projecting flange or bafile 24 forming an inlet eye coaxial with runner l2.

The runner comprises a hub portion 26 of generally conical form rigidly fastened to the end of shaft |3 in any suitable manner, and a plurality of suitably shaped vanes. Each vane such as 2'. is preferably of spiral shape having an inlet edge 28 adjacent the eye of the pump, a discharge edge 29 adjacent discharge passage 2| and afree outer edge 3| movable adjacent side plate 22 with a clearance space therebetween. Inlet edge 28 joins hub 26 with outer edge 3| and thus intersects the entire incoming flow of fluid. Edge 28 comprises a convex portion 32 adjacent hub 26 and merging into a concave portion 33. The outer end of edge 28 is provided with a stop 34 which may be made integral with the vane or may be made as a separate piece. As illustrated in Figs. 1, 2 and 3, stop 34 may be shaped as an extension of the web of vane 2'! or, as illustrated in Figs. 4 and 5, the stop may be formed as a pair of flanges 35 extending from edge 28 along outer edge 3| and on opposite sides of vane 2! and having their trailing edges faired into the vane. It will be understood that other forms of stop may also be used, such as a stop forming a continuous flange extending along outer edge 3| on both sides of vane 21 and around the end of edge 28. Fig. 3 shows the contour of edge 28 of the runner illustrated in Figs. 1 and 2 and a plurality of contour lines assumed to be drawn on the surface of the edge. Edge portion 32 may be given any cross section facilitating the flow of fluid on both sides thereof and may be substantially semielliptical in cross section with a small radius at the tip, but edge portion 33 is transversely rounded with a relatively large radius at least immediately adjacent stop as. The cross sections of edge portions 32 and 33 vary from point to point to insure a smooth transition between the two edge portions.

During normal operation of the pump, runner I2 is rotated through shaft i3 in the counterclockwise direction as viewed in Fig. 2, and the rotating spiral vanes of the runner cause the fluid to enter the suction opening formed in the passage l7 and to travel along the surfaces of the impeller vanes and of the side plate 22 to be ultimately delivered to the spiral discharge conduit 2| and to the discharge piping connected therewith. The fluid stream in passage I! is guided by guide vane I9 which prevents the fluid from taking a whirling movement. Filamentary material, such as string and rubber bands, carried by the fluid flow is generally of such density as to remain suspended in the fluid during the passage thereof through the difierent parts of the pump. Some of the material may impinge on vane 52 which has a leading or inlet edge sloping in the direction of the fluid flow from the wall of casing H toward the axis of passage ll. The vane thus releases filamentary material impinging thereon toward the center of the fluid stream and therefore at a point removed from the clearance space between the outer edges 3| of the runner vanes and side plate 22.

Some of the filamentary material also impinges on the inlet edge 28 of each runner vane in such manner as to lie across the edge and to be held thereagainst by the flow of fluid. As a result of the convex form of edge 32 and under the action of centrifugal force, filamentary material caught on the edge is gradually deflected outwardly along the edge, and if edge 28 were of uniform configuration, the material would be guided to ultimately be released into the clearance between edge 3| and side plate 22. To prevent the material from penetrating within the clearance space, the inlet edge portion 33 is made concave to collect the material impinging on the edge portions 32 and 33. The material moving along the edge is thus stopped before reaching the clearance between the runner and the casing, by means of stop 34. and remains on the rounded portion of the inlet edge just adjacent but within the stop. The material resting on the rounded portion of the edge is in unstable equilibrium and is ultimately released into the fluid stream on one or on the other side of the vane at a point removed from edge 3|.

It will be observed that flange 24 is disposed ahead of and adjacent the path of stop 34. The flange thus cooperates with inlet edge 28 including stop 34 in preventing filamentary material from entering the clearance (space between edge 3| and the adjacent portions of the casing by deflecting the flow of fluid from the clearance and by preventing filamentary material from impinging on the portion of edge 28 adjacent edge 3| and on stop 34. As filamentary material otherwise passing through the pump has no tendency to enter the clearances between the runner and the side plates, the continued undisturbed operation of the pump is thus insured.

In the embodiment illustrated in Figs. 6 and 7, the pump comprises a casing 36 of the branched tubular type defining an inlet passage for the flow of fluid and adapted to be connected with inlet piping (not shown). The runner 37 of the pump is of the axial or propeller type, arranged within a sleeve 38 forming part of casing 36 or made as a separate piece extending into the discharge pipe 39 of the pump. Runner 3'! is mounted on a suitable shaft 4| supported in a water lubricated bearing 42 and sealed by means of a stuffing box 43. Bearing 42 is mounted in a bearing housing 44 extending into casing 36 and including stufiing box 43 and a plurality of guide vanes or baffles 46. Sleeve 38 is likewise provided with a plurality of guide vanes 47. The guide vanes have their inlet or leading edges sloping in the direction of the fluid flow from the wall of the casing to release filamentary material impinging thereon, towards the center of the fluid stream. The runner is provided with a plurality of vanes 48 mounted on the hub 49 fastened on shaft 4|. Each vane has an inlet edge and a discharge edge 52 joined by a free outer edge 53 movable adjacent sleeve 38 with clearance therebetween. Inlet edge 5| comprises a portion 54 sloping in the direction of the fluid flow from the hub outward and on which material may impinge and thereafter progress in direction of the fluid flow under the action of centrifugal force. Each inlet edge is provided at the outer end with a stop 56 and the portion 57 thereof intermediate portion 54 and stop 56 is made concave and rounded immediately within stop 56 to collect filamentary material impinging on the inlet edge and to release the material into thefluid stream at'a point removed from the clearance between the outer edge and the adjacent portion of the casing. This action is assisted by a flange 58 extending inwardly from sleeve 38 and adjacent the path of stop 56 to prevent filamentary material from impinging on the stop and to guide the material away from the clearance between the runner and the casing. The action of the different parts of the pump in preventing clogging of the pump clearance is thus obtained in substantially the same manner as in the embodiments illustrated in Figs. 1 to 4, and a detailed explanation thereof is accordingly omitted.

Although but a few embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. A rotary hydraulic machine adapted to conduct a fluid stream containing filamentary material comprising a casing and an open type runner mounted for rotation within said casing, said runner comprising a vane having an inlet edge and a free radially outer edge adjacent a portion of said casing with a peripheral clearance therebetween, said inlet edge having a stop located adjacent its outer end and having a concave portion adjacent the stop and being transversely rounded immediately within said stop for collecting filamentary material impinging on said inlet edge and for releasing the collected material into the fluid stream at a point removed from the clearance between said outer edge and the adjacent portion of said casing.

2. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a hub and a vane having an outer edge and an inlet edge joining said hub with said outer edge, said inlet edge having a portion adjacent said hub of convex form for deflecting filamentary material impinging thereon and having a concave portion forming a stop located adjacent its radially outer end, and being transversely rounded on different radii from said hub toward said stop for collecting the filamentary material impinging on said vane and for releasing the collected material into the fluid stream at a point removed from said outer edge.

3. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge, the inlet edge being convex adjacent the inner end viewed axially and concave adjacent the outer end thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

4. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge, the inlet edge being convex adjacent the inner end viewed axially and concave adjacent the outer end thereof and being transversely rounded between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

5. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge, the inlet edge being convex adjacent and being concave remote from the axis of said runner and being transversely rounded on different radii between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

6. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge, the inlet edge being convex adjacent the inner end viewed axially and concave adjacent the outer end thereof and being transversely rounded on different radii fairing into each other between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

'7. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge and a stop extending from the inlet edge and having a concave portion adjacent the stop for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

8. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and an outer edge, the inlet edge being convex adjacent the inner end and concave adjacent the outer end thereof and forming a stop extending from the outer end thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

9. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and a free outer edge, the inlet edge being made convex adjacent the inner end and concave adjacent the outer end thereof to form a stop extending from the outer end thereof, the inlet edge of said vane being transversely rounded between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected fllamentary material into the fluid stream at a point removed from the outer edge.

10. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and a free outer edge, the inlet edge being made convex adjacent the inner end and concave adjacent the outer end thereof forming a stop extending from the outer end thereof, the inlet edge of said vane being transversely rounded on different radii between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

11. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and a free outer edge, the inlet edge being made convex adjacent the inner end and concave adjacent the outer end thereof and forming a stop extending from the outer end thereof, the inlet edge of said vane being transversely rounded on different radii fairing into each other between the ends thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point removed from the outer edge.

12. In a rotary hydraulic machine for conducting a fluid stream containing filamentary material, a runner comprising a vane having an inlet edge and a free outer edge, the inlet edge being made convex adjacent the inner end and. concave adjacent the outer end thereof and forming a stop extending from the outer end thereof, the inlet edge of said vane being transversely rounded on a relatively small radius at the inner end and a relatively large radius at the outer end thereof for collecting filamentary material impinging on the inlet edge and for releasing the collected filamentary material into the fluid stream at a point 10 remover from the outer edge.

FRANK R. FORREST.

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