US 3640474 A
An impeller for heavy duty comminuting pumps may include a blade which is not only disposed in angular relation to its turning axis but may have an irregularly curved surface, or several such surfaces arranged to intersect each other along a line which is angularly disposed with respect to the turning axis.
Description (OCR text may contain errors)
1 1 1111mm mics Pmem 1151 3,640,474
Niedl Feb. 0, 1972  IMPIELLER FOR HEAVY DUTY COMMHNUTING PUMPS 1 Reference Cited  Inventor: Georg Niedl, 1m Bisch 664, Schoan, UNITED STATES PATENTS Ledtensten 2,956,503 10/1960 Neidl ..103/111 x  Filed: Feb. 18, 1969 3,113,734 12/1963 Neidl ..24l/74  APPLNO 822342 Primary ExaminerD0nald G. Kelly Related US. Application Data Anamey chnsten & sabol  Division of Ser. No. 452,502, May 3, 1965, Pat. No. ABSTRACT An impeller for heavy duty comminuting pumps may include a blade which is not only disposed in angular relation to its turn- 52] us. c1 ..241/46.02, 103/111,210/174, ing axis but may have an irregularly curved Surface or 241/4606 241/ 415/121 such surfaces arranged to intersect each other along a line 51 1111. C1 ..B02C 18/06, F04d 29/04, B0111 35/26 which is angulafly disposed with respect to me mming am  Field 01 Search ..24l/46, 46.02, 46.06, 46.11,
241/90, 74; 103/111.1, 11l;415/121, 210/174 7 ClaimgQDr-awingligures L I I Mum I54 5 I50 I 7 g j I5 A f M 140 PATENTEQFEB 8 I972 SHEEY 1 0F 2 FIG. 2
INVENTOR GEORGE NE IDL IMPELLER FOR IIIEAVY DUTY COMMINUTING PUMPS This application is a division of our copending application, Ser. No. 452,502, filed May 3,1965, for a PUMP.
This invention relates to rotary pumps of the type disclosed in my prior US. Pat. Nos. 2,956,503; 3,005,597; 3,060,862; 3,067,960; 3,113,734 and 3,120,353 and more particularly to the development of said type of machines for separating solids and liquids.
In all known filter construction whether they used centrifugal force, screens, vacuum, pressure, filter cloth, filter drums, or other means, the filtering machine was construed as a separate single purpose unit. Said constructions presented, in addition, always the difficulty that the filter openings readily clogged and had to be cleaned in relatively short time intervals by scrapers or other means.
It is a principal object of the invention to provide a machine which avoids said drawbacks.
A further object of the invention is to provide a machine which allows of combining processing operations such as mixing, tearing, comminuting, grinding, homogenizing, centrifuging, milling, kneading as well as separating, sorting, distilling with a filtering and pumping action.
Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein preferred embodiments of the invention are shown by way of example.
In the drawings:
FIG. I is a view of a disc-shaped rotor;
FIG. 2 is a view ofthe rotor of FIG. 11 in its folded form;
FIG. 3 is a sectional view of such rotor;
FIG. 4 is a perspective view of the rotor inside the pump housing;
FIG. 5 is a view of the same rotor provided with teeth;
FIG. 6 is a longitudinal section, partly in elevation, of a pump with the rotor of FIGS. 11 to 15, cooperating with grooves in the pump housing, and
FIGS. 7, 8, and 9 show various schematic forms of folded pump discs.
FIGS. I to 9 illustrate various fonns and shapes of the impeller discs. FIG. 2 shows the rotor disc 139 of FIG. I, mounted on shaft 140, folded about its center axis 141, as better seen from the section I-I, where the folding angle has been designated a. The inclined mounting of the folded impeller disc I39 is shown in FIG. 4, where it is rotated in a housing I44 having an inlet I45 and an outlet I46.
FIGS. 5 and 6 show an embodiment of the invention where the folded impeller disc I47 is, similar to the modification shown in FIG. 9 of the disclosure of US. Pat. No. 3,502,274, provided with teeth I54 and I55 running in radial grooves 148 of a housing I49 and in concentric grooves 150 and 151 of covers 152 and I53, respectively. The parts 149, I52, and I53 are perforated by passages 157 through which the filtrate is withdrawn.
Such folded toothed rotor may be disposed in a simple spiral housing rotating with its teeth in radial grooves, whereby the spiral housing is provided with a suitable outlet. Instead of being flat, one or both of the two wings of the folded impeller may be arched to form a scoop.
The folded rotor of FIG. 7 is no longer flat as in FIG. 3 but a folded semicircle 161. The one flank 162 of the quarter circle is left in its plane, the second flank 163 is turned over by 90 to position I64. The thus formed rotor is secured obliquely to the shaft 165 which extends perpendicularly to the plane of the drawings.
FIG. 8 shows the half circle I66, 167 with its flank 167 turned towards 168. In FIG. 9, the part 171 of the generatrix I70, I71 is tilted by 90 to position 172, producing the rotor I70, 172. Such rotors, which might better be designated operating members, may replace the rotor I of FIG. I of the disclosure of U.S. Pat. No. 3,502,274; instead of using the rotor 170, 172 of FIG. 9, a double-arched body 170, 171 may be employed. According to may investigations, it is of advantage in many cases that 170 and I71 be shaped to form a drag curve Schlep kurve see Rothe, Hohere Mathematic, page I40, erlag or Wrssenschaft und Fachbuch-GmbI-I.,
In the modifications of the rotor shown in FIGS. 1-9, it is not necessary to tilt the half generatrix, such as I63, I67, 171 by The angle may be larger or smaller, even negative. In the latter case, said half generatrices are turned not counterclockwise but clockwise with respect to the other half generatrices I62, I66, I70.
Neither is it necessary that in the rotors of FIGS. 8-9 the wings have equal length, i.e., end on the same diameter circle. They may have different lengths, or one wing may be completely omitted. On the other hand, a rotor may have more than two wings.
The wings may be perforated, and they may have other types of curvatures than those shown. I
The use of folded rotors as shown in FIGS. 4-9 is particularly suitable for the treatment of long or strong fibered or very tough material. Viewing, e.g., the machine of FIG. 5, it will be seen that a current of slurry entering through inlet will be divided in half on hitting against the folded edge of rotor 147. This has two advantages: Shifting of the material inside the engine is less likely, and separation through the passages 157 is faster and more intensive. The two rear edges of the rotor sweep on rotation the apertures 157 with a short interval; there is a rather wide angle before the next sweep of the two edges takes place, and apertures have, therefore, more time to recover from the passage'of the filtered material than in case of a rotor disc as shown in FIG. I of the disclosure of US. Pat. No. 3,502,274, where the angle is I80. Such periodical combing of the passages 157 can be further improved by making the same of different sizes, as indicated e.g., in FIG. 9 of the disclosure ofU.S. Pat. No. 3,502,274.
I. A pump and strainer assembly comprising a stationary pump housing having an inner wall defined by a surface of revolution forming a pump chamber in said housing, one end of said chamber being provided with an inlet, a rotary drive shaft mounted in said chamber concentric with the axis of said surface of revolution, an impeller secured to said drive shaft, a shell enclosing at least a part of said pump housing, said shell forming with the wall of said enclosed pump housing a separate outlet chamber, the portion of said housing enclosed by said shell being provided with a plurality of strainer passages, said impeller comprising a plurality of semielliptical wings, said wings being generally disposed in planes angularly related to each other and angularly related with respect to the axis of said surface of revolution.
2. An assembly as claimed in claim I wherein said impeller is folded to form two wings.
3. An assembly as claimed in claim 2 wherein said wings are formed by two planes meeting along a straight line.
4. An assembly as claimed in claim 2 wherein said wings are formed by two intersecting generally arcuately formed members.
5. An assembly as claimed in claim 2 wherein the folding edge of the impeller is opposite the inlet of the pump chamber.
6. An assembly as claimed in claim 2 wherein said wings have different lengths.
7. An assembly as claimed in claim I, wherein at least a portion of said inner wall defining the pump chamber is provided with a series of circumferential grooves, and the margins of said semielliptical wings are provided with teeth for operative engagement with said circumferential grooves.