US1031722A - Ejector. - Google Patents

Description

M. LEBLANO.

HECTOR.

APPLICATION FILED SEPT.1Ov 1907.

Patented July 9, 1912 R w in mmfi mw m W n a W? m; n

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- UNITED STATES PATENT orrro.

MAURICE LEBLANC, OF CROISSY, FRANCE, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO SOCIETE ANONYME POUR LEXPLOITATION DES PEOCEDES WESTINGHOUiE-LEBLANC, OF PARIS, FRANCE.

EJECTOB.

Specification of Letters Patent.

Patented July 9, 1912.

Application filed September 10, 1907. Serial No. 392,122.

dent of Croissy, Seine et Oise, F rance,

have invented a new and useful Improvement in Ejectors, is a specification. This invention relates to ejectors operated by steam or other elastic fluids.

The object of the present invention is to provide an ejector of that type which shall e both selfas tarting and also capable of maintaining a high vacuum. To this end the cross sectional area of the throat of the mixing cone is automatically varied in accordance with-the variation in the vacuum obtained. I In the accompanying drawings Figures 1 and 2am diagrammatic views indicating in longitudinal section two different forms of construction of an ordinary ejector. Fig. 3 is a similar view indicating by way of example one form of construction for carr ing into efiect an ejector according to t e present invention and Fig. 4 is a cross section on the line X-Y of Fig. 3.

Referring to Fig. 1 indicating an ordinary ejector the motive fluid supplied under pressure passes through a nozzle 1 into a chamber 2 opposite .a passage 3, called a mixing cone, in which the velocity energy is-transformed into work of compression. This motive fluid entrains by' friction the fluids which fill the chamber 2 and flow into it by the inlet 4. These fluids before coming into contact with the stream of motive fluid must pass annular directing nozzles 5 and 6. The mixing cone 3 exhausts into a spac' 7 in which there is a constantpressure P. Designating the working pressure which it is desiredto maintain in the chamher 2 by p the form of the mixing cone should vary as the ratio When the ratio which varies with the nature of the fluid is greater than a certain number or mixture of fluids passing through the mixing cone and which is 0.58 for steam and 0.51 for air, the mixing cone should be divergent, as shown in Fig. 1.

ratio mixing cone should be at first convergent and then divergent, as shown in F 1g. 2.

l/Vhen the issmaller than this number the of which the following The junction 8 of the convergent anddi- .vergent portions of the mixing cone is called the throat.

This throat should be made smaller with respect to the inlet end of the' convergent portion of the mixing cone as the ratio g diminishes. Assuming that in order to maintain a high vacuum in the chamber 2 the ejector is constructed as shown in Fig. 2, then on starting the apps-- ratus the 'pressure p would be equal to P and during the period preceding the establishment of the working condition the ratio 1 P prised between unity and the value corresponding to the desired working'conditions. At the moment of starting the ejector should have a form absolutely different from that which is normally most suitable. Further the ejectorwould refuse to work and the pressure p in the chamber 2 would become greater instead of becoming less than the-' pressure P. Experience shows that an ejector with a convergent'mixing cone followed or not by a divergent mixing cone cannot be started unless the convergence is would pass through all the values-comslightthat is to say-unless the ratio of the throat section to the inlet section of the mixing cone is nearly 1. It follows there fore that an ejector proportioned as it should be for maintaining a high vacuum as soon as working conditions have been established, cannot be started. Conversely an ejector in which all the parts are incapable of variation but which 'is 'ada ted to be self-starting will be unableto profiuoe a high vacuum. Therefore in order that an ejector shall be able to produce a high vacuum it is necessary that during the starting. period the section of the throat shall gradually diminish in accordance with the increase in the yacuum obtained. It is also necessary, inorder that the effect produced by the appalatus may be constant, and in order that the apparatus may be self-starting after an accidental derangement that the variations in the throat section shall be automatically determined by the variationsv in the vacuum obtained. The crosssectional area of the throat of a converging mix ng cone may for example be varied by dist rting the, walls.

In Figs. .3 and i this method of varying the cross;sectrional,area of the throat is illus- Ill erated together and axis trated as applied to a mixing cone of tangular section and constant length, the width being gradually varied from one end to the other of the mixing cone.

Within a casing or receiving chamber 9 having two parallel plane faces at distance 10 the one from the other are arranged two plates having a profile such as that shown from 11 to 12. These plates are equal in width to the distance 10 and are supported against the two plane faces of the casing 9 by means of broad flanges so. as to reduce wear. These plates are pivoted at points 13, 13, and it is obvio from the drawing that by causing these plates-to oscillate about the points 13, 13, the-section of the throat of the mixing cone can be variedet will. l The ends of the plates 'opbposite to the pivoted ends are connected.- y pivoted links 14 -14 ,m rod 15 whi'hreciprocetesimaguide bearin 16 and which is provided with a piston woidring in a dashpot 17. B this" means the plates 11, 162' are n y 011 oil mixing cone remains unaltered In order to renderithe'movemeht of the E two plates 11', militaristic it is suficient to by experience tolls per hold them apart 'bv means of springs'18, 18'

attached to opposite walls of the casing 9,- Thus as a vacuum is created in the chamber 2, the ressure within. themixing cone will fall, w gile'the pressure'outside the cone will remain constant and equal to P. The plates will thentend to close together, but since the tn'sion on the springs will thus be in creased a state of equilibrium will be established-'tmtil "the vacuum isyagain increased, when ,th'eplates will approach one another still further. The springs will naturally have tobeadiuated, so that as the lates apfluid the proach one another the tension w' increase would to the desired law in order that the thropt of the mixing cone may at everymoment correspond in section to the vacuum obtaine (l.'1; v The presence of the dashpot will oppose stile set-ting up of any oscillating movements ofthetwo plates 11, 12, h The etarting of this e'ector haabeen I ectly'automati ji' What-I claim 1s;- j '1. In an 'ejector' operated by an elastic 'fluid the 1 combination with an "admissl on nozale for' theunotive fluid, of a. receiver chamber, a mixing cone located within such chamber, means subjected tofitltte pressure within "the. mixing fcone and'the pressure within the receive? chamber for symmetricallyclosing two'i'walls of the mixing cone, and means fon'rprovidi'ng an'increasing resistance to the-pierce of said ressure. 3 2. In an ejectionoperated y an'elastic fluid, the combination with an admission; nozzle for the motive fluid, of a receiver chamber, a mixing cone located within said chamber and'comprising two opposite stationary walls and two opposite movable walls pivoted at the inlet end of the mixing cone and springs providing a predetermined increasing resistance to the movement of the pivoted walls due to the excess of pressure in the receiver chamber overt the pressure within the said mixing cone.

3. In an ejector operated by an elastic fluid, the combination with an admission nozzle for the motive fluid, of a receiver chamber, a mixing cone located within the said chamber and comprising two opposite stationary walls and two opposite movable spring-retracted walls pivoted at the inlet end of the mixing cone, means for equalizing the movements of the-said two pivoted walls anda dash-pot for regulating the oscillation of said pivoted walls.

4. In; combination in an ejector, an admis sion nozzle for the motive fluid, a mixing cone, means for directing the fluid to be exhausted into the mixing cone, and means dependent upon the pressure within said mixmg cone for varying'the cross sectional area of the outlet of the mixing cone in'accordancewit-hthe variation in the vacuum producedby the ejector.

5. In an ejector operated by an elastic fluid, the combination with an admission nozzle for motive fluid of a receiving chamber, a mixing cone located within said receiv' chamber, means for directing the fluid to be'exhausted into said cone, and means dependent u on the pressure within said receiving cham r and within said mixing cone for varying the cross sectional area of the outlet ofthe mixing cone in accordance with the variation in the vacuum produced byVethe-ejector. a I

'6. In an ejefioroperatedby an elastic v V a tipn w ith'an admission nozzle, for thel-findtiye fluid, of a mixing cone," ineans .for'xdirecting the fluid to rexha'usted' into 'the mixing-cone, and means dependent upoijf'the pressure within Salli cone gfor; v e thej'convergence of the mixin accordance with the varia tions' 'ur the name of fluid exhausted.

- "7. In an ejector operated by an elastic fluid,

the combination'with an admission nozzle for the motivefluid, a mixing cone, means for directing the fluid to "be exhausted into the cone, and means for varying the position of the walls of the mixing'cone so that relative roportions' of the mixing cone are varied in accordance with the variations in the vacuum obtained.

8; In an ejecton'the combination with an admission nozzle for the motive fluid, a mixing cone rovided with two stationary and two mova le Walls, and means for varying the position ofcthe movable walls inac; cordance with the variation in the vacuum produced by the ejector.

9. In an ejector operated by an elastic fluid, the combination with an admission nozzle of a mixing cone, means for directing the fluid to be exhausted into the mixing (one, a receiving chamber in which said mixing cone is located and means responsive to the differential of pressure within the mixing cone and the receiving chamber for varying the cross sectional area of the mixing cone in accordance with the variations in the vacuum roduced by the ejector.

10. In an ejector operated by an elastic fluid, the combination with an admission nozzle for the motive fluid of a mixing cone comprising two opposite stationary walls and two opposite movable walls and springs for controlling the movements of said movable walls.

11. In an ejector operated by an elastic fluid the combination with an admission nozzle for the motive fluid of a mixing cone provided with movable walls and yielding means for controlling the motion of said walls.

1". In an ejector operated by an elastic fluid, the combination with the admission nozzle for the motive fluid of a mixing cone provided with means for varying the cross sectional area of the outlet of the mixing cone and springs for controlling the opera; tion of said means.

13. In an elastic fluid operated ejector device, an admission nozzle for motive fluid, a mixing cone, and means for automatically varying the cross'sectional area of the out let of the mixing (one in accortlalue with the varying amounts of fluid exhausted by saiddevico 14. In an ast fluid operated ejector device, a motive tluid admission nozzle, a mixing cone, means for directing the fluid to be exhausted into the mixing cone and means for automatically varying the outlet area of the mixing cone in accordance with the variation in the vacuum produced by the device.

In testimony whereof I have hereunto subscribed my name this 22nd day of August 1907.

MAURI CE LEBLANC. Witnesses:

DEAN B. Mason, Alumni Dulles.

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