WO1980000472A1

WO1980000472A1 - Method and apparatus for pumping fragile articles

Info

Publication number: WO1980000472A1
Application number: PCT/US1979/000672
Authority: WO
Inventors: M Gurth
Original assignee: M Gurth
Priority date: 1978-08-30
Filing date: 1979-08-30
Publication date: 1980-03-20
Also published as: EP0016223A4; EP0016223A1; CA1157315A

Abstract

A pump for pumping fragile articles including fish and glasses without damage includes a rotary pump having a plain disc impeller (32) disposed in a substantially cylindrical chamber (26) of a housing (24) with an inlet (28) into, or coaxial of the impeller into the housing and an outlet (30) from the periphery of the chamber, with the rotor arranged to provide a substantially unobstructed passage between the inlet past the rotor to the outlet of the pump. The method includes pumping fragile articles in a fluid medium by means of a disc impeller pump having an unobstructed passageway between the inlet and outlet of the pump.

Description

METHOD AND APPARATUS FOR PUMPING FRAGILE ARTICLES

BACKGROUND OF THE INVENTION The present invention relates to fluid pumps and pertains particularly to method and apparatus for pumping fragile articles. Rotary disc pumps have been known for a considerable length of time. These pumps, however, have not gained widespread use because they have been unable in the past to compete effectively with positive displacement pumps and bladed impeller pumps for the pumping of fluids.

The prior art of which applicant is aware indicates that such pumps have been proposed as early as 1913 , with minor improve ments being made through the years until the present time . The prior art is exemplified, for example, by the following prior art patents:

U. S. Patent No. 1, 061, 142, issued May 16, 1913 to N. Tesia,

U. S. Patent No. 2, 087, 834 issued July 20, 1937 to Brown et al,

U. S. Patent No. 3, 487, 784, issued January 6, 1970 to Rafferty et al,

U. S. Patent No. 3, 644, 051 , issued February 22, 1972 to Schapiro, U. S. Patent No. 4, 025, 225, issued May 24, 1977 to

Durant.

Other patents of interest include British Specification No. 179, 043 , dated May 4, 1922 to N. Tesla, and

French Patent Specification No. 866, 706, issued May 31, 1941 to Girodin. These pumps are all based on the theory that the friction of the fluid on the surfaces of the plates of the rotor during rotation of the rotor develops a centrifugal force propelling the fluid out toward the periphery of the plates. These all, however, maintain and recognize the necessity for maintaining a fairly close tolerance of the spacing between the discs. There has long existed a need for systems for conveying fragile articles rapidly and conveniently without damage thereto. Fruits and vegetables, for example, are currently conveyed by means of screw-type conveyors when it is essential to convey them without a fluid medium. Prior to the present invention, there has been no known technique for conveying such articles by means of a pump in a fluid medium without damage thereto. Currently, some pumps are used to unload some fish from fishing vessels into processing tanks or the like at canneries. Such pumps, however, are of the vane type and result in a considerable amount of damage to the fish.

Vane type pumps are also used in the pumping of coal, slurry and the like. Such pumps, while effective in moving the slurry, are subject to highwear and rapid deterioration. They are also subject to clogging.

It is therefore desirable that a pump be available which is capable of rapidly and effectively conveying fragile articles by means of a fluid medium over a reasonable distance. SUMMARY AND OBJECTS OF THE INVENTION It is accordingly the primary object of the present invention to overcome the problems of the prior art by providing a pump capable of pumping fragile articles in a fluid medium.

Another object of the present invention is to provide an effective pump for safely and conveniently moving fragile articles in a fluid medium without damage thereto. In accordance with the primary aspect of the present invention, a pump is provided for moving of fragile articles, with the pump comprising a plain disc impeller with a substantially unobstructed passage between the inlet and outlet of the pump. The fluid is pumped through the pump by means of friction and shear forces applied thereto by means of a plain disc impeller, with the fragile articles being carried along in the fluid stream without impact with portions of the pump assembly. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the present invention will become apparent from the following description when read in conjunction with the drawings, wherein:

Figure 1 is a diagram of a typical use of the pump for moving fish or the like. Figure 2 is a front elevation view of the pump, with portions cut away.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2 . Figure 4 is a front elevation view of an alternative form of the pump, with a portion cut away. Figure 5 is a sectional view taken on line 5-5 of Figure 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the drawings, particularly to Figure 1 , there is illustrated a pump, designated generally by the numeral 10, pumping live fish 12 from a tank 14 in a fluid 16 such as water into a second tank 18. The second tank also contains fluid 16 such as water. The pump is provided with an inlet conduit 20 of sufficient size to convey the fish and fluid without damage to the fish into the pump 10, and therethrough and by way of an outlet conduit 22 into the second tank 18. As best seen in Figures 2 and 3, the pump 10 includes a housing 24 having a generally cylindrical chamber 26 in which is mounted a disc rotor. The housing includes an inlet 28 into the chamber 26 and an outlet 30 from the periphery of the chamber 26. As best seen in Figure 3, the pump rotor includes a first plain disc 32 having a plane impelling surface and a substantially conical-shaped streamlining portion 33 projecting toward and concentric with the inlet 28 and the axis of the chamber 26. A second plain disc 34 also of plane configuration includes a central opening 36 concentric with and substantially the same diameter of the inlet 28. The second disc 34 is connected to the inner or drive disc 32 by means of a plurality of pins 38 spaced around the axis and closely adjacent thereto. These pins are preferably as close to the central axis of the rotor as possible. This spacing is critical in the handling of fragile articles in that the movement of fluid and articles through the chamber is such that the velocity of the articles at this point is fairly low and will tend to be moving at about the same velocity and direction as the pins such that impact therewith is substantially avoided This configuration as shown, for example, in Figures 2 and 3, provides an essentially unobstructed passage through the pump housing from the inlet 28 to the outlet 30. The spacing between the discs 32 and 34 should exceed the maximum dimension of the articles to be pumped in order to insure adequate spacing for unobstructed passage of an article of a predetermined size. Prior plain disc pumps have emphasized the necessity of close spacing between the discs in the pump. Heretofore, the spacing of such pumps, typically referred to as shear force pumps, has been considered to be fairly critical. It has always been considered necessary in the past to have a fairly close spacing between the discs in order to get the necessary shear force to propel the fluid through the pump. It has been recognized, however, in Rafferty et al, Patent No. 3, 487, 784, Column 5, that the psacing can be as great as 1 /4 of an inch and still obtain flow of fluid therethrough. The Rafferty pump, however, is a very low pressure pump primari ly for the purpose of pumping blood and does not recognize the possibility of pumping articles in a fluid, or pumping with large spacing between the discs.

Applicant has discovered that Large spacing between the discs is possible and of from 1 /2 an inch up to at least as much as a foot or more . Applicant has essentially discovered a pump construction and method capable of pumping highly fragile articles such as live fish and the like, from one place to another such as from one tank to another, from a fishing vessel to the processing tanks and the like. The rotor of the pump in Figure 3 is mounted on a suitable drive shaft 40 such as by means of a nut 42. The drive shaft is mounted in a suitable bearing support bracket 44 by means of a bearing 46 and includes suitable seal means 48 for sealing the shaft within the housing. The housing is supported on a suitable base member 50 for mounting in the usual manner.

The applicant has tested and demonstrated the safety and feasibility of the present invention by means of a prototype in which goldfish were recirculated from a tank through the pump and back to the tank for a period of approximately two hours . Several hundred goldfish were involved and no noticeable damage or side effects were noted. The day following the test, a single one of the more than 200 goldfish was found to be dead. This fish was inspected and no bruises or contusions were found on the fish. An alternate embodiment of the invention is shown in Figure 4, wherein a pump designated generally by the numeral 52 includes a housing 54 having a substantially cylindrical inner chamber 56 , in which is mounted a rotor 58 which is also a plain disc impeller having a forwardly directed, somewhat conicalshaped vortex reducing portion 59, which projects substantially the width of the impeller chamber to an inlet 60 of the housing. The housing, which is of a substantially cylindrical configuration, includes an outlet 62 which joins tangentially of the rotor housing. The impeller or rotor 58 is mounted on a drive shaft 64 such as by means of a nut or the like 66 . The shaft 64 is mounted in a suitable bearing 68 mounted in a bearing support bracket 70. Suitable seal means 72 seals the shaft against leakage from the impeller chamber.

This configuration, as shown in Figure 4, is capable of pumping fragile articles such as glass tumblers, such as illustrated in Figure 4, at 74. The pump is this configuration provides a substantially unobstructed passage from the inlet past the impeller 58 into the outlet. With this arrangement, the fragile articles, such as tumblers, are maintained a sufficient distance apart so as not to impact one another and thus flow with the fluid through the impeller pump chamber from the inlet to the outlet. The articles are suspended by the fluid and cushioned against impact with the pump housing. Again, it has been found that fairly large articles may be pumped in a fluid medium, such as water, in pumps of this character. It has been found that a sing le blade impeller of the disc type as shown in Figures 4 and 5 is capable of applying sufficient force to the fluid within the housing to propel it through the outlet thereof. Thus, any number of fragile articles and items may be pumped in the pump in accordance with the invention.

For example, any number of fruits, such as apples, oranges, lemons, grapefruits, melons, tomatoes and the like, may be pumped in a pump in accordance with the invention. The necessary steps of the invention include the selection of a rotary disc impeller pump having a substantially unobstructed passageway between the inlet and the outlet with a sufficient spacing between the plane facing of the discs of the impeller and the opposing wail or impeller disc to permit passage of articles of a predetermined size. The articles are then disposed in a suitable fluid medium such as water and communicated with the inlet of the pump, with the outlet communicating by suitable conduits with the place where it is desired to pump the articles.

Thus, it can be seen that any number of fragile articles can be pumped by the method and apparatus of the invention.

While I have described my invention by means of specific embodiments, it is to be understood that numerous changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. Having described my invention, I now claim:

Claims

1. A fragile article pump for pumping fragile articles in a fluid medium, comprising in combination: a housing having a substantially cylindrical rotor chamber, an inlet coaxial of said chamber; an outlet communicating with and extending outwardly from the outer diameter of said chamber; and a rotary impeller mounted in said chamber for rotation and comprising a disc having a plain face positioned for contact with fluid in said chamber and spaced from the inlet sufficient to permit the passage of fragile articles from said inlet past the face of said disc to the outlet.

2. The pump of Claim 1, wherein said impeller is spaced from the inlet wall a distance of at least one inch.

3. The pump of Claim 1, wherein said impeller disc is spaced from the inlet wall a distance of from 1/2 inch to twenty four inches .

4. The pump of Claim 1, including a second disc having a central opening theretgrough and spaced from said first disc a sufficient distance and connected to said first disc for rotation therewith by means providing a substantially unobstructed passageway between s aid discs from said inlet to said outlet for the passage of fragile articles of a predetermined size.

5. The pump of Claim 4, wherein said second disc is connected to said first disc by means of a plurality of connecting rods spaced annularly around the axis of the discs at the innermost diameter of the outer disc.

6. The pump of Claim 1, including vortex reducing means on said inner disc.

7. The pump of Claim 6, wherein said vortex reducing means comprises a substantially conical projection extending axiaily of said disc toward said inlet.

8. The pump of Claim 6, wherein said conical projection extends substantially to said inlet.

9. A method of pumping fragile articles of a predetermined size comprising the steps of: providing a fluid pump having a smooth disc impeller mounted within a housing with an unobstructed passage defined between an inlet and an outlet, said inlet, outlet and passage having a cross-sectional area exceeding said predetermined size, and introducing a mixture of said articles and a fluid into the inlet of said pump, while simultaneously therewith rotating the impeller of said pump in said chamber about the axis thereof, said impeller comprising a rotating disc mounted closely adjacent the wall opposite the inlet and spaced from the wall having the inlet a sufficient distance to provide an unobstructed passage between the rotating disc and the opposite wall for the passage of delicate fluid borne articles, at a rate to establish and maintain a flow of said mixture of particles and fluid through said pump.

10. The method of Claim 9, wherein said articles are live fish.

11. The method of Claim 9, wherein said articles are glass tumblers.