US921118A - Pump. - Google Patents

Description

A.'T. KASLEY.

' PUMP.

APPLIOATION FILED MAY 26, 1906 Patented May 11, 1909;

2 SHEETS-SHEET 1.

INVENTOR (m /(1nd s BY O\ Y ATTORNEY A; T. KASLEY.

PUMP. APPLICATION FILED MAY 26, 1905:

UNITED s'rATEsPA'r NT OFFICE.

ALEXANDER T. KASLEY, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

' PUMP.

' Specification of Letters Patent.

Patented May 11, 1909.

Application filed May 26, 1905. Serial No. 262,494.

1 gheny and State ofPcnnsylvania, have inpressors are utili vented a new and useful Improvement in Pumps, of which the following is a specification. i

This invention relates to blowers and pumps, and more particularly to centrifugal or rotary blowers and pumps.

A d1st1nct1on I make between blowers and compressors and pumps is that pum s areutilized forliquids, while blowers an comzed for gaseous or elastic 'huds.

Since the invention hereinafter set forth is generic, I do not wish to limit it to any division of the broad term pump, but intend that this application shall be broad enough to cover all centrifu al or rotary pumps whatsoever they may be termed by the trade.

Since the advent of the steamturbine on w a: commercial footing, it has been the desire of many manufacturers to obtain a centrifugal pump capable of operating efliciently at desirable turbine speeds whereby the pump and turbine can be direct connected.

Up to the time of this invention I believe it has been next to impossible to build a centrifugal pump with any range of application to meet the demands of steam turbine work. The conditions in most cases and those presenting the greatest number of obstacles to the manufacturer of eflicient pumps have been high power, high speed and low head. For high speed and low head the necessary peripheral speed gives a diameter It of the runner or pump im elller that is often much less than the size 0 the pump intake pipe, if the velocities in the intake pipe are iept within reasonable limits. I [am aware that numerous schemes have been proposed to the end ofovercoming these diiiiculties, but with all of those with which I am familiar either the cost-[of the schemes or the low efficiencies of the same render them valueless.

In attempting to .devise a centrifugal pump which would meet the speed requirements of the steam turbine, I have discovered What I believe to be a new principle,

and in developing this principle I find that I am enabled to producecentrifugal pumps,

blowers and compressors which are not only capable of being driven at the ordinary steam turbine s ceds, with good efficiencies, but are more e cient than any of the centrifugal pumps, blowers and compressors which have been heretofore devised for any conditions.

In the drawin s accompanying this application I have il ustrated two pumps, each embodying the principle of this invention, and each adapted for different duties.

Figure 1 is a View in sectional elevation of what may be termed a high head pump, while Fig. 2 is a view in sectional elevatlon' of what may be termed a low head pump. Since the new principle involved 111 each is the same, it is deemed advisable to embody them in one a plication, but since the design of the. severe elements entering into the make-up of the two pumps is dilferent it' has been deemed advisable not to give the correspondingly named parts like reference characters.

Broadly, each of the forms illustrated embodies a rotatable impeller and rotatably mountcddiffuser vanes which are adapted to be rotated in the same direction as the impellcr, but at a slower speed, by the impelled fluid or by the fluid saving the outlet of the impeller. By means of these rotata'ble diffuser vanes the fluid impingin thereon strikes with much less shock, am therefore with less loss of energy than if the diffuser vanes were stationary as they are in ordinary centrifugal pumps.

Fig. 1 illustrates a-pump designed to be direct coupled to a steam turbine running at 3600 R. P. M. and is adapted to pump. agalnst a 600 foot head.

The pump consists of a casing 3, provided with suitable inlets 4 and a discharge outlet 5. The impeller 6, which is shown of a form now common and which takes the fluid, which hereafter for the sake of brevity will be termed water, at both sides near its axis, is rigidly mounted on a shaft 7 adapted to be direct connected to the turbine shaft.

Surrounding the impeller and between it, and the stationary casing 3 is a casing 8 rige idly secured to a suitably journaled idler shaft9. The connection between the casing 8 and the shaft 9 consists of a web 10, the

several portions of which are formed in the inlet of the impeller opposite to the inlet'adjacent to the blades 10.

The stationary casing as shown is provided with a volute or snail-shell chamber 12 (which may or may, not'be rovided with diffuser vanes), and with whic 1 the dischar e opening 5 cornmunicatesj The rotatab e casin 8 between the outlet of the impeller.

and t e inlet to the volute is provided with diffuser vanes 13.

The impeller, by means of its vanes, raises the water to a hi h velocity, and by means of the rotatable diffuser vanes 13 a part of the velocity energy of the water expelled from the impeller is converted into pressure energy prior to its entry into the volute, and since the difiuser vanes 13 are allowed to retate the shock of the water impinging thereagainst is mitigated, and the loss of the energy is lower or less than it would be if the diffuser vanes were stationary.

' It will beseen. that the rotating casing 8 will act as a diffusing member even if unprovided with difiuser vanes; the centrifugal.

force of the freely rotating water causing the pressure to increase and the velocity to decrease. The gain in this case is in the reduction of the friction between the water and the walls of the casing 8 .on account of the smaller relative velocity.

By means of the blades 10 and 11, which are driven through the casing 8 by means of the diffuser vanes 13, the water is given a velocity rior to its entry into the impeller, and the nal velocit is thereby stepped u gradually, and it wil be seen that there will be no pressure increase between the several steps. By thus gradually bringing the water up to speed the loss of power due to shock is greatly reduced.

Since the pressure produced in a centrifugal pump consists of two parts, one due to the centrifugal force of the Water in the run-' strikes the volutewhich will'be '1.4) 7 7 Therefore thepart of the "'res'suredue to the velocity of the water stri ing the vanes is re duced from 1 to ap roximately or and'the centrifugal force part will be increased from 1 to approximately 1; thus causing the greater art of the work 'to be done by the more e 'cient method.

Fig. 2 illustrates a pump designed to be direct connected to a-steam turbine running at 3600 R. P. M., and is adapted to pump a ainst a 200 foot head. The pum consists o a stationary casing 14, rovide with an inlet 15 and a discharge outlet 16. A runner or impeller 17, provided with any desired form of blades, is mounted on a shaft 18 ada ted to be direct coupled to the turbine. Wit this pump no stationary casing or volute is employed in the ordinary meanin though a small volute may be found desirable for conveying the water to outlet 16. A retatable casing 19, through the agency of the diffuser vanes 20 and su ports 21, is mounted on an idler shaft 22. T e casing 19, like the casing 8 of the pump illustrated in Fig. 1,

.The relative velocity ,of the water passin through the casing 19 and the casing itself:

is reduced owing to the fact that the casing revolves in thesame direction as the impeller but at aslower speed. The efficiency of this pump asin the one illustrated in Fig. 1, is increased by-increasing the centrifugal force component of the-pressure pumped at the expense of the impact or the component due to the velocity with which the water strikes the diffuser vanes. By allowing the diffuser vanes to revolve at l/n the speed of the impeller, the centrifugal part is reduced by the centrifugal force of the water in the revolving casing by the factor 1(1/n) and the impact ressure is reduced by the factor (1-1/11), but if n is greater than 1 then 1-(1/n) is greater than (11]'n) .so that the reater part of the work is done by the more cient part of the pump. As an illustration, suppose the rotating casing to revolve at about i; the speed of the impe ler then the centrifugal force of the water in the casing acting against the flow will be approximately as great as the centrifugal force in the impeller, so that the resultant pressure will be ap roximately (1 2;) or 3-, while the pressure no to impact will be reduced to approximately (1}) or 1. Thus the centrifugal component becomes three times as great as the impact instead of only being equal to it. The head is hereby reduced to approximately i= 1 instead of 1 1 2, while the skin friction between the im eller and the water, between it and the casing, could only be ap roximately ({r) -as great since the re ative velocity is 5- of what it was before, so that there is an ap reciable saving obtained by reducing the srinfriction. Since the idler shaft 22 is caused'to rotate, the energy due thereto is made available and can be used for drivin a gpnerator, or for any other purpose desire w en the conditions are suitable. In this application I have shown it driving an ordinary low head centrifu al ump which will be connected in parallel wit the pump just described. As this ordinary type of pump is now common, no description of the'same is deemed necessary, but it will be understood that the discharge outlet of this ordinary pum will communicate with the discharge out et from the pump illustrated to the left of Fig.2, and as the shaft 22 will revolve at'a relatively slow speed this ordinary type of centrifugal pump" may be successfull utilized. i

It wi lbe understood that since this invention is generic many modifications may be made from the constructions shown without departing. from the spirit of this invention. It will also be understood that a multi-stage pump employing this principle-is contemplated, and that an apparatus 0 erating in the reverse manner may be uti ized as an efficient form of turbine either for elastic or inelastic fluids.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is p v 1. In combination in a centrifugal pump, a fluid impeller, .rotatable means for imparting velocity to the fluid to be impelled prior to its contact with the impeller, and an agent receiving its energy from the impelled fluid for driving'said means.

2. In combination in acentrifugal pump, a fluid impeller, rotatable means for imparting velocity to the fluid to be impelled prior to its contact-with the impeller, and an a 'ent receiving its energy from the impelled uid for driving said means at a lower .speed than the impeller but in the same direction.

3. In combination in a centrifugal pump, a rotatable impeller, a rotatable agent with which the impelled fluid contacts in its passage between the outlet of'the im eller and the pump outlet whereby part of t e'kinetic energy of the fluid is transformed into pressure energy, and an instrumentality driven from said agent whereby the shock of the fluid prior to its-entry to said impeller is mitigated.

4. The combination in a centrifugal pump of a rotatable impeller, a stationary casing provided with an inlet port and an outlet port, a plurality of rotatable blades between,

said inlet port and said impeller and a plurality of rotatable blades between said outlet port and said impeller.

5. The combination in a centrifugal pump of a rotatable impeller, a stationary casing provided with an inlet port and an exhaust port, a rotatable casing inclosing said impeller and a plurality of blades mounted on said rotatable easing between said inlet port and said impeller.

6'. The combination in a centrifugal pump of a rotatable impeller, a stationary casing provided with an inlet port and an exhaust port, an independently rotatable casing inclcsing said impeller and a lurality of blades mounted on said rotatab e casing between said inlet port and said impeller.

7. The combination in a centrifugal pum of an impeller, a stationary casing provide with an inlet port and an outlet port, a rotatable casing between said stationary casing and said im eller and means operated by said casing for imparting velocity to said fluid prior to its contact with said impeller. 8.. The combination in a centrifugal pum of an impeller, a rotatable casing for sai impeller provided with an inlet ort and an outlet port and means operated y said casing for imparting velocity to the fluid to be im elledprior to its admission to the impe er.

9. In a centrifugal pump in combination with a fluid im eller, a rotatable means for imparting veloelty to the fluid to be impelled prior to its contact with the impeller and, an agent within said pump for driving said means.-

10. In a centrifugal pump in combination with a fluid impeller, a rotatable means for imparting velocity to the fluid to be impelled prior to its contact with the impeller and an agent within said pump for driving said means at a lower speed than the impeller but in the same direction.

11. The combination ina centrifugal pump provided with a fluid inlet and a fluid outlet, of a fluid impeller, a plurality of blades between said im eller and said fluid inlet for imparting velocity to the fluid to be im elled rior to its contact with sald 1mpe er an means for driving said blades in In testimony whereof, I have hereunto subscribed my name this 22nd day of May,

' ALEXANDER T. KASLEY. Witnesses:

DAVID WILLIAMS,

JNo. S. GREEN.

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