US3044408A - Rotary pump - Google Patents

Description

July 17, 1962 F. M. MELLOTT ROTARY PUMP Filed Jan. 6, 1961 INVENTbR. FRANK M MELLOT T By @M ,2 W

ATTORNEYS 3,044,408 RQTARY PUM? F rank M. Mellott, Penryn, Calif assignor of one-half to 1 James A. Dingus, Sacramento, Calif.

Filed Jan. 6, 1961, Ser. No. 81,055 1 Claim. (Cl. 103-103) The invention relates to improvements in centrifugal pumps and, more particularly, to rotary pumps capable of handling fluids associated with entrained solid matter.

In the field of rotary pumps adapted to handle slurries or mixtures of fluids and solids, one of the major problems encountered is that of wear. The solids act as highly eifective abrading agents both against the rotating elements and the stationary ones.

It is therefore an object of the invention. to provide a rotary pump which is capable of pumping fluids and fluidsolid mixtures with a minimum of wear.

It is another object of the invention to provide a rotary pump which, with a simple conversion, is capable of han-v dling not only light slurries, such as of wood pulp, but heavy ones, such as sand and gravel mixtures, as well.

It is yet another object of the invention to provide a rotary pump which is relatively inexpensive to manufacture and in which maintenance costs are low.

It is a further object of the invention to provide a ro-' tary pump which is extremely reliable in operation.

It is another object of the invention to provide a generally improved rotary pump.

Other objects, together with the foregoing, are attained in the embodiment described in the following description and shown in the accompanying drawing in which:

FIGURE 1 is a view looking along the axis of the intake pipe, a portion of the housing being removed to show the impeller construction; 4

FIGURE 2 is a section, the plane of the section being indicated by the line 22 in FIGURE 1; and

FIGURE 3 is a view comparable to that of FIGURE 2 but with a modified form of impeller.

While the rotary pump of the invention is susceptible of numerous physical embodiments, depending on the environment and requirements of use, substantial numbers of the herein shown and described embodiments have been made and used, and have performed in an eminently successful manner.

In the form shown in FIGURES 1 and 2, the pump, generally designated by the numeral 12, comprises a hemispherical or bell-shaped body 13, or housing, having at its apex an inlet port 14. The inlet port 14 is symmetrically disposed on a vertical axis 16, it being understood, however, that the pumps use is not restricted to the particular orientation shown in the figures, and that the pump also functions in a highly eflicient manner with the axis 16 in any desired attitude or degree of inclination. The inlet port 14 is defined by an inlet connector 17 threaded or otherwise formed to receive any desired type of inlet pipe 18.

The diametral or base end portion of the hemispherical body 13 terminates in an annular flange 21 provided with a plurality of threaded openings 22 adapted to receive fastenings 23 serving to clamp to the body a circular cover plate 26.

Adjacent the flanged portion of the body 13, the body is provided with an outlet or discharge port 31 and a corresponding outlet pipe 32, the axis 33 of the pipe 32 being at right angles to the inlet pipe axis 16 and parallel to the plane of the cover plate 26.

Adding stiffness to the cover plate 26 and serving, as well, to support the impeller, generally designated by the numeral 41, is a supporting member 42. The supporting member 42 includes a flange 43 mounted concentrically on the cover plate 26, as by fastenings 44, and an up- 2 standing hollow cylindrical boss 46 provided with a suitable journal bearing 47. Disposed within a chamber 48 defined by a shoulder 4 at the lower end of the boss 46 and the cover plate 26 is a fiuid seal 50, of any conventional make.

Rotatably mounted. within the journal 47 and projecting, through an opening 51 in the cover plate, interiorly into the hemispherical chamber 52, formed by the body and the cover plate, is a shaft 56 provided with thread-s 57. Mounted on the threads 57 and keyed thereto as by a member 58 is the impeller 41, or rotor. The shaft 56 is rotated by any conventional power source.

In the form of the device shown in FIGURES l and 2, the impeller comprises a substantially circluar base plate 61 and a plurality of blades 62 mounted thereon. The blades are generally spiralled in transverse cross section, as appears most clearly in FIGURE 1, and the outer periphery of each blade is arcuate in profile with its center of curvature substantially coincident with the center of curvature of the bell-shaped body 13. At their inner ends, the blades are secured to a centrally threaded boss 66 mounted on the base plate 61 and in threaded engagement with the shaft 56.

Owing to the fact that the radial length of each of the blades is only approximately one-half the radial distance between the axis of rotation 16 and the adjacent portion of the flange 21, a substantial volume, in the form of a hollow hemispherical shell, exists between the outer pe riphery or envelope of the rotating impeller blades and the inner wall of the hemispherical body 13. The apparent effect of this geometrical arrangement is to set up a powerful vortex, the centrifugal force of which is suflicient to hurl outwardly the solid particles entrained in the fluid-solid mixture entering through the inlet port 14. In other words, rotation of the impeller creates a strong swirling type of current in the space bounded by the interior walls of the body and the envelope defined by the arcuate outer peripheries of the revolving blades. As a consequence, solids, upon entering through the inlet port, are immediately urged laterally and into the fluid vortex. Centrifugal force tends to keep the solids from impinging on the blades and wear on the blades is thereby minimized.

In the case of mixtures with fairly light entrained solids, the FIGURES land 2 form of the device has been found to be extremely effective in balancing the upward (see FIGURE 2) component of motion resulting from the upward movement of the fluid as it enters the pump and the lateral or horizontal component resulting from centrifugal force. The resultant effect is that the entrained solids are urged into a helical path of increasing diameter, ultimately to discharge through the outlet port, and While the solids are in the helical path they impinge only with minimum frequency against either the blades or the body walls. The precise proportions of the blades relative to the body are determined to some extent by trial and error but the relative dimensions shown in' FIGURE 2 have been found to achieve a very satisfactory flow, with a minimum of wear for many light slurry pumping applications. 1

FIGURE 3, on the other hand, illustrates a modified form which has been utilized with great success in connection with fluid-solid mixtures wherein the entrained solids are heavy and particularly where the solids are of a relatively efficient aerodynamic form, such as rounded particles of gravel, pea gravel, for example. In this situation, the swirl or vortex created by' the impeller takes a longer time to deflect the upwardly moving (FIG- URE 3) solid and in order to avoid impact between the solid particles and the impeller the blades 71 are low in profile and terminate in a plane substantially parallel to the plane of the cover plate 26 at a substantial distance from the apex of the b0dy,'i.e. at a substantial distance from the inlet port 14. 7

It is to be noted that comparable elements in all of the FIGURES are designated by the same reference nu- Ineral. This is done partly for convenience and help in analysis and partly'to illustratethe ease of interchanging the impeller to meet various requirements without having toalter the other components of the pump.

As can be seen most clearly in FIGURE 3, the irnpeller blades 71 are mounted on a base plate 73 and join at a central, hollow, threaded hub 74 mounted onthe threads of a shaft '76 journalled in the bearing 47.

It can therefore be seen that I have provided a highly versatile rotary pump which is especially suitable for use in handling fiuid-solid'mixtures of various kinds.

What is claimed is:

A rotary pump comprising:

(a) a hemispherical body symmetrical about an axis;

said body including an intake port on said axis adjacent the apex of said body and a discharge port transversely disposed with respect to said axis and located adjacent the base of said body;

, (b) a circular cover plate mounted onthe base of said body and disposed at right angles with respect to said axis to form with said body a hemispherical chamber;

(c) a shaft supporting member mounted concentrically on said cover plate; 7

(d) a shaft journalled in-said supporting member and extending through said cover plate into said hemispherical chamber; and

(e) an impeller mounted on said shaft, said impeller including a plurality of convex blades having a cen-- ter of curvature located approximately at the center of curvature of said hemispherical body, each of said blades extending radially a distance equal approximately to one-half the distance between said shaft and the periphery of said cover plate.

References Cited in the file of this patent UNITED STATES PATENTS 765,969 7 Hanson July 26, 1904 2,434,896 Ayers J an. 27, 1948 2,495,895 Hervert Jan. 31, 1950 2,635,548 Brawley Apr. 21, 1953 2,699,764 Kiekhaefer Jan. 18, 1955 2,918,876 Howe Dec. 29, 1959 2,958,293 Praz Nov. 1, 1960 FOREIGN PATENTS 20,216 Great Britain Nov. 9, 1900 613,892 Great Britain Dec. 3, 1948

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