US977101A - Centrifugal pump. - Google Patents

Description

F. W. KROGH.

GBNTRIFUGAL PUMP. l

10N FILED JUNI: 29

Patented N0v.29, 1910.

2 SHBETS-SHEET 1.

and

P. W. KROGH. GBNTRIPUGAL PUM.

APPLIOATION FILED JUNE 29, 1909. 977, 1 01 l Patented Nov. 29, 1910.

FERDINAND W. KROGH, OF SAN FRANCISCO, CALIFORNIA.

CENTRIFUGAL PUMP.

Specication of Letters Patent. Patented NOV. 29', 1910.

Application filed .Tune 29, 1909. Serial No. 505,079.

To all whom 'it may concern:

Be it known that I, FERDINAND W. KRoGH,

citizen of the United States, residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in Centrifugal Pumps,- of which the following is a specification.

My invention relates to improvements in what are known as centrifugal impeller pumps.

It consists in a means for more perfectly balancing the running parts of the pump with relation to the suction and discharge pressure, and in automatically regulating these pressures.

It also comprises details of construction and combinations of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which- Figure 'l is a sectional view of the impeller. F ig. 2 is a section of the pump taken in the plane of its axis. "Fig 3 is a view showingr a plurality o`f pumps connected in series. Fig. 4 shows the application to a double suction.

In this class of pumps there is a wide vari'- ation between the pressure on the inlet or suction side of the impeller and the discharge side, which is at all times under a considerable pressure. c

It is the object of my invention to provide a means for automatically equalizing such pressures at all times, so that the moving parts will be perfectly balanced within their casing.

A is a casing which may be in one or more parts, each containing a revoluble impeller 2 mounted upon a shaft 3 through which power is applied in any suitable manner to revolve the impeller.

The impeller may be in the form -of a disk having the curved water-ways 4, and these water-ways connect through the hubvor central portion, as at 5, with the inlet or suc tion pipe or passage 6. By the rapid revolution of this impeller when charged with the liquid, a centrifugal action is set up which draws the water into the impeller, and throws it outwardly into the annular surrounding passage 7, which passage connects with thejdischarge pipe 8, this pipe being substantially tangent with the annular passage 7 so that the liquid Will'be delivered therefrom.

O u I n In case the pumps are arranged in series,

as shown in Fig. 3, the discharge from thev rst impeller will be returned through passages as at 9, into the hub of the second impeller, thence passing youtwardly through the curved waterways 4a, and so on through as many series as it may be found desirable to employ.

It will be manifest that the pressures involved by thel suction and discharge acting in the line of the shaft, will tend to force the impeller constantly to one side within the shell or casing A. In order to overcome this difiiculty, I have shown the' following construction The hub 10 of the impeller has flanges 11 projecting on each side, and adapted to contact with the opposite sides of the that as the impeller revolves, the ends of the hub revolve within these flanges, and thus form the chambers 12-12a as shown. A In order to form more perfect joints between the annular flanges 13 and the hub, I have shown rings 15 fitting around the ends of the hub, and these rings are constantly pressed againstthe inner ends of the flanges 13 by springs 16.

14 are independent passages made in the runner, and these passages extend from the periphery of the runner, and open through the end of the hub opposite to the suction, and radially opposite to the openings of the impeller passa es 4 which communicate ywith the -suction en The revolution of the impeller causes a constant centrifugal action which, drawing .Water through the suction pipe will discharge it through the passages 4 and into the annular chambers 7 whence it passes to the d'scharge, ory tothe following casingv as the case may be. The pressure 'Within this annular discharge passage `is very considerable, and this pressure is allowed to pass intolthe sides of the casing A by reason of the. space within the casing around the impeller, and as the lit between the part 1.0 and the anges the runner thatsaid runner 13 of the casing is a running fit, a certain amount of water will leak into the chambers 12-121. The action of the suction through the waterways 4, and the entrance thereto at 5, constantly acts to draw the water out of the chamber `12,'and thus the tendency of v the pressure of the water admitted into the chamber 12 would be to force t-he impeller toward the suction side of the casing; but the supplemental passages 14 opening into the interior'end of the hub, and opposite to the suction side, the leakage from the chamber 12'r1 through the space between the casing and the flange 11 at that end of the hub, will be drawn out by the centrifugal action of the water through the passages 14. Thus, if there is a greater suction of Water through the passages 14 than through the passages 4, the tendency of the hub andthe impeller will be to move'toward the side of the casing opposite to the suction, and if the increase is from the suction side, the impeller will be moved in that direction. In other words, the centrifugal Vaction of the pump produces the suction through the inner pipe, 6, and this suction tends' to produce a vacuum which causes such pressure upon will be forced toward the suction side. This action takes place up to a certain neutral point within the pump; beyond that the centrifugal force commences to raise the water through the discharge pipe and that will produce 'a direct pressure in the opposite direction, the pressure being reversed and becoming an actual back pressure. This neutral point is ditl'icult to locate even by the use of the gages, but it is at this point that the anges, 11 and 13, co-act to 'continually adjust the balancing of the runner. When the runner moves toward the suction side it opens a space between the flange, 11, and the inner side of the case and water may now pass from the discharge which is nthe pressure side of the pump into the channel, 12, and thus create a counter-pressure against the suction. When the runner moves\ toward the opposite side of the case it enables this water to pass from the channel, 12, into the suction passage, thus tending to create a vacuum within the channel, 12, and this acting against the end of the hub presented to the channel serves to again equalize the pressure in that direction. By reason of the 'foregoing construction an automat-ic bala\ce of the impeller within its casing is nstantly maintained. It will be seen by reference to Fig. 3 that the same operation is repeated in each of the subsequent impelletls, and `thus the apparatus will be made self-balancing, and any tendency of the impeller to run toward either side within the casing will be constantly neutralized. y

In Fig. 4 ysuction pipes or passages 6 are connected with opposite sides of the casing.

Under this condition it will be seen that the variation in pressures, upon opposite sides of the impeller will still be 1)alanced as heretofore described, by the action within the chambers 12, and 12a.

Having thus described my invention, what I claim and desire to secure by Letters Patent is` 1. The combination in a centrifugal pump, of a casing having central inlet and peripheral discharge passages, an impeller revoluble within the casing, the impeller having curved water ways connecting with the inlet passage and having a hub through the center of one side of which the inlet ends of the Water-ways open, said hub and the innerl faces of the casing having annular flanges forming with the adjacent sides of the casing and hub, intermediate chambers, and said impeller having other passage-ways which are independent of the first-named ones and whose inner ends open through the side of the hub opposite to that through which the inlet ends of the first passages open, both of said passages leading outwardly through the periphery of the impeller.

2. The combination in a centrifugal pump of a casing and co-acting impeller, said impeller having a hub and said hub having annular flanges on its opposite faces between its periphery and axial center, and said casing having inwardly extending flanges within which the periphery of the hub has a running fit, said impeller having two sets of water-ways, one of which opens through one .side of the hub and leads outwardly through the periphery of the impeller,'andl the other has its inlet end opening through the side of the hub opposite to that containing the inlet end of the rstnamed water-ways, and leading outwardly through the periphery of the impeller.

3. 'g1/he combination in a centrifugal pump of an incased impeller, a shaft upon which it is mounted, means forming inclosed chambers at opposite sides of the hub between said hub and casing, said impeller having one set of water-ways, of'which open through .one side of the hub and thence lead outwardly through the periphery of the impeller, and having a second series of water-ways, the inlet ends of which open through the other side of the impeller while their outer ends lead through the periphery of the impeller, the secondnamed water-ways being independent of the first one and serving to create a counterbalance to the suction on of the impeller.

4.. A centrifugal pump having in combination Ia casing having a central inlet and the opposite side a peripheral discharge, an impeller inclosed the inlet ends.

and revoluble within the casing, having af'/ hub adapted to .contact endwise with the opposite sides of the casing, said casin having` annular inwardly extending anges within which the ends of the hub of the impeller have a running t, said flangesl on the hub and casing and the'adjacent faces of the hub and casing inclosing side chambers, said impeller having curved waterways connecting at their inner ends with the inlet passage 'of the casing, and said impeller Having other and independent curved water-ways whose inner ends lead through the hub on the side thereof opposite to that which contains the inlet end of the firstnamed passages, said second water-ways lealding through the periphery of the ime ler. p 5. The combination in a centrifugal pump, of a casing having a centrally located inlet passage upon one side, and an annular peripheraLdischarge passage, 'a Ishaft-driven 20 impeller revoluble within the casing, said impeller-havin curved waterways connecting with the in et passage at one end of the impeller hub, other waterways connecting with the casing through the hub at the op- 25 posite side from the inlet passage, flanges FERDINAND w. KEQGH.

Witnesses:

GEO. H. STRONG, CHARLES EDELMAN.

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