US1529774A - Steam ejector with cooled diffuser - Google Patents

Description

2 Sheets-Sheet 1 March 17, 1925. v

A. DELAS STEAM EJECTOR WITH COOLED`DIFFUSER- Original Filed Oct. 19, 1920 f/Z 1 l EE March '17, 1925. 1,529,774

A. DELAS STEAM EJEGTOR WITH COOLED DIFFUSER original Filed oct. 19, 1920 2 Sheets-sheet 2 i l l Patented Mar. 17, 1925.

UNITED STATES PATENT OFFICE.

ALBERT DELAS, OF PARIS, FRANCE, ASSIGNOR T DELAS CONDENSER CORPORATION,

OF NEW YORK, N. Y., A CORPORATION 0F DELAVARE.

STEAM EJECTOR WITH COOLED DIFFUSER.

Application led October 19, 1920, Serial No. 417,989. Renewed August 4, 1924.

To aZZ whom t may concern:

Be it known that I, ALBERT DELAS, a citizen of the Republic of France, residing at Paris, France, have invented certain new and useful Improvements in Steam Ejectors with Cooled Diffusers, of which the following is a full, clear, and exact description.

The invention which constitutes the subject matter of this application relates to ejectors, and has for its object to effect certain improvements in the construction and method of operation of ejectors of the type disclosed in my Patents No. 1,374,990, April 19, 1921, and Nos. 1,499,349 and 1,499,350, July 1, 1924, and my copending application Ser. No. 260,6011/2, iiled Oct. 31, 1918.

In my above mentioned prior applications I have pointed out certain novel important results obtained by circulating cooling fluid around the walls of the converging portion of the diffuser and further advantages and important results obtained by also cooling the neck and outlet portions of the diffuser. Stated somewhat generally, such cooling increases both the efficiency and stability of operation of ejectors. A preferred form of such ejector comprises a diffuser provided with a converging inlet portion, a substantially cylindrical neck portion, a substantially cylindrical outlet portion and with means for circulating a cooling fluid around the exterior of the walls of the said inlet, neck and outlet portions of the diffuser.

In order to enhance the cooling effect, the walls of the diffuser should be made thin and out of good heat conductivity. During the operation, the diffuser is subjected to wide fluctuations of temperature, especially when steam is passing through the diffuser, and, through accident or mistake, the circulation of the cooling fluid is stopped. Under such circumstances the diuser may reach a temperature higher than that of its enclosing casing, and in the absence of special provisions would be subjected to strains and consequent buckling or other deformation. In my prior applications I have disclosed arrangements in which the diffuser is provided with an expansion joint at, at least, one end thereof to permit expansion and contraction of .the diffuser with respect to the remaining structures. If sea water is to be employed as the cooling Huid it is important that the expansion-permitting-means be so tight that entrance thereof into the diffuser or path of the motive and entrained iiuid is prevented, especially when the lat ter mixture is to be condensed and the fluid of condensation eventually returned to the boilers.

One of the objects of the present invention is to provide expansion-permitting-means meeting the above stated requirements without sacrificing the solidarity and simplicity of the general structure.

In my said prior applications I have disclosed arrangements in which the diusers are surrounded by sleeves in comparatively close proximity to the same and between which dilfusers and sleeves the cooling Huid is caused to flow. By virtue of this arrangement a maximum cooling effect is obtained for a given quantity of cooling iiuid. Ihave discovered that it is especially important that the wall of the neck of the two diffusers should be maintained at a low temperature.

Another object of the invention is to provide an arrangement and method for intensively cooling the di'user neck portion. 80

A further object of the invention is to provide a reservoir or storage chamber for the cooling fluid adjacent and surrounding the diffuser so that in case of cessation of circulation of said fluid the otherwise incidental rise in temperature of the diffuser walls is prevented. Other objects and advantages will appear as the invention is hereinafter disclosed.

Referring to the drawings which illustrate what I now consider preferred forms of apparatus embodying my invention:

Fig. 1 is a sectional elevation of a single stage ejector embodying certain features of the invention.

F ig. 2 is a view similar to Fig. 1, but illustrating an additional feature of invention. f

Figs. 3 and 4c are views similar to 2, but illustrating modifications.

Fig. 5 is a sectional elevation of a two stage ejector system embodying certain features of the invention.

Fig. 6 is a sectional elevation of a two stage ejector system in which the two ejectors are arranged side by side instead of in axial alignment, as in Fig. 5.

Fig. 7 is asectiontalren on the line A-B of Fig. 6.

fFig. 8 is a view similar to Fig.l 6, but illustrating certain modifications.

Fig. 9 isa view similar to Fig. 8, but illus.'- trating further modifications.

Fig. 10 is a section on the line A-B oi Fig. 9.

Figs. 11. and illustrating certain features of the various forms of the invention.

Referring to Fig. 17 it will be seen that the ejector there illust 1ated comprises an enclosing casing 1 provided with a nozzle 2 adapted to be suppliedwith steam or other elastic motive fluidunder pressure and to discharge the same into the chamber 8i. The latter is adapted to communicate at l with the source of fluid,V such `as air, vapor, steam ormixture of' the same, whose pressureis to be raised .in the ejector. vSuitably secured within the casing 1 is a. tubular diffuser 5 through which the mixture ofniotive fluid and entrained Huid passes. I have illustrated my preferred form of diffuser, which comprises a converging inlet portion 6, a substantially cylindrical neclr .portion 7 and a substantially cylindrical outlet portion 8. Tater orA other cooling fluid is introduced through the opening 9 into the.. annular chamber 10, bounded bythe casing 1 and a cylindrical portion y11 of a sleeve member 12 suitably secured within thecasing and surrounding the upper endof the diffuser 5. The member 12 terminates at its lower portion in .a tube which, speakingrgenerally, conforms. to the shape of the exterior of' the diffuser. It will be noted Athat the member 12 is constricted near the necl of the dii'- 'l'useiz The ycylindrical portion 11 is provided with a peripheral row or series of holes 13 through which the cooling fluid flows from the annular chamber 10 into the space between the sleeve 12andY the exterior of' the diffuser 5. The sleeve. 12 discharges into a reservoir orstorage chamber le p`rovided in the casing 1 and surrounding the .sleeve and diffuser. The cooling fluid leaves :the chamber 14- through the hole or aperture 15 provided ,in the casing 1 :adjacent the top .of the chamber 14h lt will be understood by vthose skilled in the art that steam issuing from the nozzle 2 will entrain the air and vapor or other lfluid in the chamber 3 and impart velocity thereto. The mixture of motive and eu.- trained fluids then passes `through the diff .fuser 5 when, by rconversion of velocity linto pressure, its pressure is raised. Tater o1' other cooling fluid is supplied from anysuit7 able source and flows as follows: Entering at the aperture 9 the cooling fluid flows 12 are enlarged detail viewsK around the chamber 10 and through the holes 13A into the space between sleeve 12 and diffuser 5. It will be appreciated that the cooling fluid is spread evenly around the diii'user by'virtue of the construction above described. The cooling fluid then flows downwardly in the sleeve 12 and around the exterior of the walls of the difi'user 5 cooling the same. rlhe device is thereby rendered highly stable and efhcient in its operation. The cooling fluid flows from the sleeve 12 into the chamber 14: and out at exit 15. Even though the circulation should cease for any reason during the operation of the ejector the diffuser walls would nevertheless be maintained at a comparatively lowv temperature by the large mass oil' fluid in the storage cham-ber 14.

ds previously stated, it is important that the neck of the diffuser bemaintained at a low temperature. By virtue of the constriction of the sleeve i2 the velocity of the stream of cooling fluid is raised at and adjacent they constricted section so that the wall of the neck portion of the diffuser is intensively cooled.

For reasons hereinbefore stated, l prefer to provide the diffuser 5 with `expansionpe1init'tinLG-ineans which may assume various forms. line form .is illustrated in Fig. 2 and may be constructed substantiallyas follows: y

The diffuser 5i is fnredly secured at. its upper end with respect to the casing 1, but its outlet end 8 passes through a stuffingbox 16. The latter comprises a gland portion secured to the |casing 1 and in which the packing is held by a nut or locking ring 17. Obviously a fluid-tight, diflusenexpansionprmitting joint is provided by the structure described, and interminglingof the cooling fluid and ejected fluid is prevented.

A different form of expansion joint is illustrated in Figs. 2l and 11 and may be conf structed substantially follows: rlhe lower end 8 of the diffuser 5- has secured thereto an externally threaded annular member or screw18 provided with anut 19. il. centrally a-pertured undulated or corrugated disc .or diaphragm 2G of metal or other suit able material is secured between the meinbers 18 and 19. The outer edge ofthe said disc 20 is secured between the. casing 1 and a nut 21 cooperating therewith `as 'clearly indicated in Fig. 11. A. fluid-tight but diffuser-erpansioiipei-initting joint between thediiifuser and casing 1 is thereby secured.

ln both of the forms of invention illustrated in Figs. 2 and 3 the diffuser is placed in position by inserting the same downwardly into the casing 1 andsubsequently, in the form shown in Fig. 27 tightening the nut 17 of the stuffing box or, .in the case of the form shownin Figs. 3 and 11., tighteningthenut 19. The nuts 19 and 2l. may

be provided with notches 22 to effect their rotation. l prefer also to provide the lower extremity of the diffuser and member 18 with notches 23, one of which is shown in Fig. 11, whereby the diffuser and member 18 may be held against rotation while the nut 19 is being turned, thereby preventing any torsional strains either on the diffuser or the oint between the same and said member 18.

In the form of invention shown in Figs. L and 12 the lower end of the diffuser is fixed and the upper end permitted to move with respect to the casing. The lower end 8 of the diffuser has secured thereto an externally threaded member 24 adapted to screw into the casing 1 thus constituting a fixed joint. The upper part of the diffuser is provided with an undulated or corrugated portion 27, whereby the diffuseiI may be elastically or yieldingly connected to the casing. The member' may be provided with notches 28 for turning the same. ln order to prevent torsional strain between the diffuser and member 24 during the turning of the latter notches 29 are preferably provided in the lower end of the diffuser'. By inserting the wrench or other tool in both notches 28 and 29 the diffuser and member 24C will turn as a unit and all tendency toward relative rotation of these members is avoided.

l have described above some of the pre ferred forms of fluid-tight expansion joints which may be employed and have thus far described certain features of the invention as applied to single stage ejectors. The invention may also be applied to multistage ejectors, as will hereinafter appear.

In Fig. 5 l have shown a two stage ejector in which the two ejectors are axially arranged and connected in series to act on the elastic fluid whose pressure is to be raised. ln view of the similarity between the two ejectors and the one shown in Fig. 1 no detailed description is necessary. Sufiice it to say that the second stage ejector has certain of its parts, which correspond to the parts of the first stage ejector, designated by the same reference numerals with an added prime. In this form of the invention the water or other cooling fluid enters at 9,leaves the first stage at 15, passes through the pipe 30 into the second stage at 9' and leaves at 15. It will be noted that the water passes around the first` stage diffuser first rather than through the second stage first because water as cold as possible should be employed in the first stage where the pressure is lowest.

llhile the arrangement of ejectors shown in Fig. 5 possesses many desirable features, it is disadvantageous to a certain extent, in that the steam or motive fluid nozzle 2', of the second stage ejector, and a portion of its supply pipe are located directly in the path ofthe mixture of motive and entrained fluid dischai ged from the first stage and entrained in the second stage, giving rise to an objectional elevation in temperature of the last mentioned fluid. `rin arrange-ment for overcoming this objection is illustrated in Figs. 6 and 7 of which many of the illustrated parts will be recognized in view of the preceding description.

In Figs. 6 and 7 the ejectors of the two stages are placed side by side, the first stage ejector discharging its mixture of motive and entrained fluids into the second stage chamber 8 through a pipe 31. lWhile the water or other diffuser-cooling fluid may be passed through the two stages successively, as shown in Fig. 5, is possible. and in some respects preferable, to pass this cooling fluid through the two stages in parallel. In this arrangement the water entering the cooling spaces of both stages is cold, as that entering the second stage has not been heated by first passing through the first stage. The surface of both diffusers is maintained as cold as possible which is highly advantageous. One arrangement whereby the last described circulation of the cooling fluid may be secured is shown in Figs. 6 and '7, and may be described as follows:

The water or cooling fluid is introduced at 9, and spreads in the annular chamber 10 of the first stage ejector where it. divides. A portion flows through the first stage between the sleeve 12 and diffuser' 5 while another portion flows through the channel 32 into the annular chamber 10 of the second stage. The passage of the cooling fluid through each stage will be understood in view of the preceding description. rlhe cooling fluid discharged from the rst stage at 15 passes through a channel or passage 33 into the storage space 1d of the second stage which discharges through the exit opening 15.

In multi-stage. ejector systems it is quite often desirable to employ an interstage jet condenser. When the water employed for cooling is pure (not salt water), or when the fluid discharged from the ejectors is not to be returned to boilers, the water supplied to interstage condensers may be tapped from the water of the diffuserfcooling system. A suitable arrangement whereby this may be accomplished is illustrated in Fig. 8, and may be constructed substantially as follows;

Calling attention to the last mentioned figure, it will be seen that the outlet 8 of the first stage diffuser 5 has attached thereto a bell 34 provided with holes or perforations 35 through which a part of the cooling fluid in the chamber 14 enters to condense the steam or other condensible fluid discharged from the first stage. The condensed fluid is withdrawn or leaves at 36 while the gaseous or elastic fluid passes to the second stage through the channel or passage 38 isto be employedto augmentl and heat thev boiler feed' Water, the form of' linvention illustrated in lFig. 8 is not desirable,f;as the;

cooling fluid is impure. The form of inven-4 tion shown in Figs. 9 and l0 may then be employed.

In thisI form of the invention the :bell-p34:- is connected to the` outlet 8 ofk they dilfuser. by a fluid tight joint and the upper Vpart of said bell is located in a chamber, 39 adapted to be supplied at 4L()` With water or condensing fluid from any suitable source, such as a maincondenser (not shown). In certain cases the Water from the main condenser, a part of which is injected into the interstage condenser to condense the steam issu-r ing from the first stage, 1s too Warm to beV employed for cooling-.the diffuser and `should be separated from the coolingA fluid.; By virtue of the structureshown in FigsjQ and l0 this result isalso achieved;-

In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, to-; gether with the apparatuswhich I now consider to represent the best embodiments thereof, but I desire tov have it understood that the apparatus disclosed is only illustrative and the invention can be carried out by other means. Also, While itisdesigned to use the various features and elements in the combinations and relations described, some of these may be altered andr others omitted, and some of the features of eachr modification may be embodied in the otherwithoutinterfering With. the morer general results and effects outlined, and the invention extends to such use.

What I claiml is:

l. The method of cooling` the diffuser of an ejector which comprises causing a ,flow of fluidin Contact with the exterior of the diffuser, and increasing the rvelocity of the fluid-adjacent the neck of the diuser.

2. rlhe method of cooling the diffuser of a Asteam actuated ejector v which comprises causing a flow of liquid in contact with: the exterior ofthe diffuser,` andfincreasing'- the velocity of the liquid adjacent the neck of the diffuser.

3. An ejector comprising,` in-combination, a nozzle,:a chamber havingfan vinlet for the fluid to be entrained and into Which saidl nozzle discharges,y a` diffuser communicating with said chamber, meansA for causing a flow of liquid inl contact With the exterior of said. diffuser, and means whereby vthe velocity of. thel fluid stream is increased adjacent the neck portion of said diffuser.

4.1An ejector comprising, in combination,- a nozzle, a chamber having an inlet for the fluid to be' entrained'and into which said nozzle discharges, a diffuse-r communicating With said chamber,andmeans comprising. a' converging-diverging sleeve surrounding said diffuser for causing a flow of cooling fluid in contact With the exterior-of` said diffuser. l

5. An ejector comprising, in combination, a diffusera casing surrounding said diffuser and forming a cooling'chamber around the same and substantially sealed at its lower portion,.and means whereby a cooling liquid may be circulated through said chamber, said means comprising an inlet for the fluid and an voutlet located adjacent the upper end of said diffuser. j

In testimony jWhereof I hereto affixmy signature.

ALBERT DELAS.

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