US1262102A

US1262102A - Fluid-translating device.

Info

Publication number: US1262102A
Application number: US86163614A
Authority: US
Inventors: Henry F Schmidt
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1914-09-14
Filing date: 1914-09-14
Publication date: 1918-04-09
Anticipated expiration: 1935-04-09

Description

H. F. SCHMIDT.

FLUID TRANSLATING DEVICE.

APPLICATION FILED SEPT. 14. 1914.

Patented Apr; 9, 1918.

H/S ATTORNEY IN FACT rrrr sArs A HENRY r. SCHMIDT, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

FLUID-TRANSLATING DEVICE.

Specification of Letters Patent.

Patented Apr. 9, 1918.

To all whom it may concern:

Be it known that I, HENRY F. SCHMIDT, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Fluid-Translating Devices, of which the following is a specification.

This invention relates to fluid translating devices, such, for example, as ejectors, in which the kinetic or velocity energy of the motive fluid is employed in exhausting fluid from a receptacle to be evacuated, or in compressing a fluid from a region of lower to a region of higher pressure.

In ejectors employing diflusers for build ing up pressure by converting kinetic into potential or pressure energy, pulsations in the medium traversing the difluser occur for various reasons. If these pulsations are of sufficient magnitude that the loss occasioned by shock results in a sufficient diminution of the velocity of the medium, and consequently of the available kinetic energy, so that the energy is reduced below that necessary to overcome the external or discharge pressure, the velocity in the diffuser will instantly fall to zero. This will reduce the expelling force to zero and consequently occasion a flow in the reverse direction or from the outlet of the diffuser back into the region of lower pressure.

An object of this invention is, therefore, to produce an ejector in which means are employed for preventing pressure oscillations in the diffuser from becoming large enough to detrimentally affect the operation of the ejector.

A further object of the invention is to produce a fluid translating device, of the kinetic type, in which means are employed for maintaining the operation of the device substantially constant for practically all varying conditions.

A. still further object is to produce a fluid translating device employing the kinetic or velocity energy, of the motive fluid delivered to it, in transferring fluid from a region of lower to a region of higher pressure, which automatically adjusts itself to variations in the quantity of fluid conveyed, thus preventing fluctuations of pressure in either the region of higher or lower pressure.

These and other objects, which Wlll be made apparent to those skilled in the art throughout the further description of the invention, are attained by apparatus embodying the features herein described and illustrated in the drawing accompanying and forming a part of this application.

In the single sheet drawing I have shown, more or less diagrammatically, a sectional view of an ejector embodying my inveir tion.

The ejector illustrated comprises a combining or suction chamber 9, which is provided with an inlet port 2, nozzles 4 for discharging fluid from a source of fluid pressure through the combining or suction chamber 9 into a diffuser 3, through which the combined media discharged from the combining chamber 9 are discharged from the lower to the higher pressure through the outlet 7 of the diffuser u.

The difiuser 3 has fitted near its outlet one or more well rounded conical nozzles S pointing in the direction of normal flow of the media through the difl'user 3. This nozzle, or nozzles, is provided so to permit the passage of fluid only through the opening and not around the edges of the diffuser. The cross-sectional area of the diffuser is so designed that subtantia-lly all the kinetic energy in'the fluid entering the diffuser is transformedinto the work of translation before reaching the first of the nozzles 8.

The nozzles 8 are so contracted that there is a slight drop of pressure throughthem to the discharge of the diffuser 7. Thus the diffuser 3 will compress or move the medium discharged from the nozzles a and entrained in the chamber 9 against a pressure slightly higher than at the outlet of the difluser 7.

It is a well known law of hydraulics and thermodynamics that the coefiicient of flow through a well rounded orifice is essentially unity, and also that the coefficient of flow through an open ended tube projecting into the medium discharging into it is approximately 27/100 of the flow through a well rounded orifice. The result is that with an arrangement of the nozzle or nozzles 8 such as disclosed, the flow in the normal direction will occur with approximately only one-half the drop of pressure through the nozzle or nozzles 8 as is required to cause a flow in the opposite direction. i

It is well known that harmonic oscilla- 'tions, such as the shock vibrations set up in fluids under certain conditions, can only be propagated-or incre'a sed in magnitude through resonance 'so' long as the resistance Which is overcome by the wave formation is equal in both directions longitudinally of the Wave motion. It will be evident, there fore, thatin the arrangement shown, resonance is prevented,and shock vibrations tending to be set up, due to the passing of a-quantityfotmedium, other than for'wvhich the diffuser was designed, will be prevented from attaining a magnitude sufiicient to cause a great enougl'i' loss of kinetic energy that. breaking down will occur. By breaking down I mean an equalization of the pressures at the outlet 7 and in the chamber 9, or momentary fluctuations of pressure in the diffuser occasioned by conditions other than variations in the delivery of fluid by the nozzles st or variations in the amount of me dium entering the chamber 9.

While I have illustratedbut one embodiment of my invention,'it will be apparent to those skilled in the art, that the drawing is merel' illustratix e, and that various changes, modifications, substitutions, additions and omissions may be made in the apparatus illustrated Without departing from the spirit and scope of my invention as set forth by the appended claims.

What I claimis:

1. In an ejector, a suction chamber, a dif fuser'communicating therewith, a nozzle for delivering expelling medium through the diffuser, and a plurality of con-verging nozzles' of pro gressively increasing area located at the-dischargeend of the effective portion of the-diffuser, pointing in the direction offlow through the diffuser and passing all of fthe fluid 'issuing from the diffuser.

2' In an ejecting device, a chamber to which medium to be expelled is delivered, a diffuser communicating therewith, and through which the medium is expelled, a nozzle for delivering expelling medium through the diffuser, and a converging nozzle extending across the outlet of the effective portion of the diffuser, converging in the direction of the normalflow of medium, and passing-all the fluid issuing from the diffuser;

3. In an ejecting device, a chamber to which fluid to "be exp'elled' is delivered, a diffuser communicating therewith, and through which the fluid is expelled, means for delivering a stream of expelling fluid through said diffuser, and a Well rounded nozzle, located at the end of the effective portion of the diffuser, pointing in'the direction "of flow through the diffuser, and

passing allot the fluid issuing from the diffuses.

i In'an ejecting device, a chamber to which medium to be expelled is delivered,

. a diffuser? communicating therewith-, and;

the effective portion of the diffuser and offering a greater resistance to flow ina direction oppositeto the normal flow than'in the direction of the normal flow through the ejector. V I

6. In combination with an ejector, means located atthe outlet of the effective portion of the diffuser for preventing upsetting, comprising Well rounded nozzles of successively increasing area and "with their outlets pointing in the direction of flow through the diffuser.

7. In an apparatus of the characterde- V scribed, a chamber from Which medium is to be exhausted, a diffuser communicating therewith, and through Which medium is expelled, means for delivering expelling fluid through the'diffuser, and means located Within the diffuserfor dampening harmonic Wavespropagated'in-the diifuser.

8. In an apparatus'of the character described, a chamber from avhich medium is to be exhausted, a di'liuser'communicating therewith, and through which medium is" expelled, means for discharging an ex pelling mediumthrough said difiuser, and means comprising a plurality of converging nozzles located at the discharge end ofthe effective portion of the diffuser and of successively increasing area.

9. In an apparatus of the character described, a chamber from which medium is to be exhausted, having a medium inlet and a medium outlet port, means for discharging expelling fluid throughthe outlet port of said chamber, a difluser communicating with the outlet port and a plurality of valveless orifices intercepting the diffuser and offering a greaterresistance to'flow in one direction than in the other.

In testimony whereof, I have hereunto subscribed .my name this 21st day of August,

G; W. l\IoGHEE,- E. W. MCCALLISTER.

Coislfofthii iietht inay beobtaine'd"ior 'five'cents each, by addressing the Commissioner of Patents,

Washington, D. C.