US2910223A

US2910223A - Friction pumps

Info

Publication number: US2910223A
Application number: US505341A
Authority: US
Inventors: Schlumbohm Peter
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-05-02
Filing date: 1955-05-02
Publication date: 1959-10-27
Anticipated expiration: 1976-10-27

Description

CCL 27, 1959 P. scHLUMBoHM FRrrc'rIoN PUMPS Filed May 2, 1955 Kw4-L Fig. 4

United States Patent O FRICTION PUMPS Peter Schlumbohm, New York, N.Y.

Application May 2, 1955, Serial No. 505,341

1 Claim. (Cl. 230-127) The invention relates to a friction pump of the type as described in my U.S. Patent 2,706,016. The invention specifically aims at a multi-stage friction pump. The invention is illustrated in Fig. 1 to Fig. 4 of the accompanying drawings by way of examples. In the friction pump described in the cited patent a plurality of concentrically superposed porous discs is attached to a shaft and the space between them forms the centrifugal space. lf the porous discs are of equal porosity a symmetrical configuration of a doublecone characterizes this impeller when rotating, due to the fact that within the impeller a given vacuum exists and that on the exterior side of both porous discs the same atmospheric pressure prevails. I made where it leaves through valve controlmeans 13. As

the discovery that by applying discs of different porosity additional effects can be obtained.

The invention is illustrated in Fig. 1 to Fig. 4 of the accompanying drawings.

Fig. 1 shows as a side view, partly in vertical section, partly in view, an impeller comprising two discs arranged on a shaft.

Fig. 2 shows as a side view, partly in vertical section, partly in view, an impeller with three discs arranged on a shaft.

Fig. 3 shows diagrammatically, partly in vertical section, partly in View, and partly broken away, a multi-stage arrangement in which two friction pumps are combined in line so that the exhaust of the iirst pump is fed to the intake of the second pump.

Fig. 4 shows diagrammatcally, partly in vertical section, partly in view, and partly broken away, a multi-stage arrangement in which six friction pumps are combined in line.

The impeller as shown in Fig. l comprises two

discs

1, 2, arranged on a shaft 4 with a space 5 between them. If the disc 1 has a smaller porosity than the disc 2, more air will enter through disc 2 than through disc 1. Y

-If disc 1 is impermeable and disc 2 is porous, no air will enter lthrough disc 1 and air will enter only through disc 2.

In the same manner a set of more than two discs will work out. If in Fig. 2 disc 1 is less porous than the

discs

2 and 3, more air will enter through discs 3 and V2 than will enter through disc 1. If such a set as shown in Fig. 1 and Fig. l2 runs in front of a co-pumping wall, the impeller will be deected into the shape of a cone as shown in Fig. 3 and Fig. 4. As shown in Fig. 3 and Fig. 4, the center of the co-pumping wall admits the gas or vapor to be pumped. The flow of the gas to be pumped is controlled by Valve means 8 (in Fig. 3) or l2 (in Fig. 4) so that the deflection of the impeller is maintained by the difference of pressure between the gas contacting disc 1 and the gas contacting the disc or discs adjacent to the copurnping wall. This means that the 360 nozzle 6 which is formed between the edge of the impeller and the copumping wall will adjust itself to the pressure conditions and will constitute a path which allows only a one-way ow of the gas or vapor pumped from vapor-zone P1 to vapor zone of higher pressure P2.

2,910,223 Patented Oct. 27, 1959 ICC This effect makes a multi-stage arrangement possible. As shown in Fig. 3, gas is fed from pressure zone P2, controlled by pipe means 9 and valve means 10, into the intake of the next impeller which pumps this fluid into the zone of still higher pressure P3, from which it is discharged through pipe 11. The valve means are of the type of back-pressure control apparatus so that the valve means open only if the pressure in the outgoing pipe is below a certain maximum. This means that the edge of the impeller will always be close enough to the co-pumping wall to insure a one-way ilow through this 360 nozzle so that gas or vapor cannot backre from the zone of the higher pressure P3 into the zone of pressure P2 nor from the zone of P2 to the zone P1. g

In the arrangement of Fig. 4 six impellers are arranged on the same shaft 4, the shaft being mounted in

bearings

14, 15. The impellers are arranged within a casing 16 and the casing has partition walls 17 to 22. Each partition wall is the co-pumping wall o-f an impeller in the arrangement as shown and each partition wall has a center opening to feed the centrifuging space between the outer disc 1 and the co-pumping wall. Starting with the lowest pressure P1 on the intake side of the first impeller, this pressure is built up by the first impeller to pressure P2, is further built up by the second impeller to pressure P3, etc., up to pressure P7 in the last chamber of casingA 16,

shown in Fig. 4, the openings in the various partition walls 17 to 22 decrease in diameter. The largest opening is in partition wall 22 in the zone of the lowest pressure P1. This variation in the diameter of the openings is a means of controlling the ow of the fluid which enters the centrifuging space of the impeller.

F or use as impermeable impeller element such as disc 1 in Fig. 1, I use a material of a very smooth surface to re duce to a minimum the friction with the boundary layer of the -uid contacting it on the outside. I found it advantageous to use discs made from metal foil, waxpaper, or organic foil.

Having now described the nature of my invention, and shown by way of examples the manner in which it may be performed,

I claim as my invention:

A centrifugal compressor comprising a casing having'- at smooth forward and rear walls joined by a cylindrical wall to delne a pumping chamber, a centrifugal impeller mounted concentrically with the cylindrical wall for rotation in said pumping chamber, said forward wall having a central opening in said forward Wall, and said opening forming an intake to said impeller, said impeller comprising a plurality of flexible axially spaced discs, at least one of said discs being of porous construction and having a forward and rear pumping surface, and one of said discs being of impermeable construction and having a forward pumping surface, the disc of porous construction being mounted closely adjacent to the forward flat wall of the casing to cooperate therewith to form a rst flow passage of uid beingl impelled by the forward surface of the porous disc, and a second flow passage for fluid being pumped which passes through the porous disc, said passage being formed by the forward surface of the impermeable disc and the rearV surface of the porous disc.

References Cited in the file of this patent UNITED STATES PATENTS 2,632,598 Wales Mar. 24, 1953 2,655,310 Schlumbohm Oct. 14, 1953 `2,706,016 Schlumbohm Apr. 12. 1955 2,739,757 Schlumbohm Mar. 27, 1956 kFOREIGN PATENTS 9,314 Great Britain -..---......--.V-..--- of 1909