US2046887A - Injector - Google Patents

Description

F. W. WALCH July 7, 1936.

INJECTOR Filed March 11, 1956 2 sheets-sheet 1 w a y n E In verz t0); ederz'c' W Pl/aZcZ,A

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INJECTOR Filed Maron 11, 195e 2 sheets-sheet 2 frederic/ IPI/ Walca, ly WQ... am

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Patented July 7, 1936 UNITED STATES n\r.IEc'.roRv

Frederick W. Walch, Newton Center, Mass., assignor to Consolidated Ashcroft Hancock Company, New York, N. Y., a corporation of Dela- Ware Application March 11, 1936, Serial No. 68,225

9 Claims.

This invention pertains to steam jet pumps of the class commonly known as injectors or inspirators, wherein the heat energy of Steam is directly converted into mechanical energy for the '5 purpose, for example, of forcing feed water into a boiler against a pressure which may be as great or greater than that of the steam supplied to the injector,the invention relating more particularly to an improved tube structure for use in 10 such injectors or inspirators and constituting an improvement upon that disclosed in my Letters Patent of the United States No. 2,032,674, dated March 3, 1936. In said patent I disclosed an improved tube structure comprising combining and l delivery tube members normally united in endto-end axial alignment (although separable one from the other) and defining a iiuid passage devoid of lateral outlets from one end of the tube structure to the other,together with means 20 whereby such tube structure, as a unit, may be mounted in an injector casing or removed therefrom Without disturbing the usual steam nozzles,

- controlling valves or other operative parts at the inlet end of the injector casing. The tube struc- 25 ture there disclosed also had provision for resisting rapid internal Wear, and for ready replacement of Worn parts.

While the tube structure of my aforesaid patent represents a very substantial advance in the 30 art, as compared with prior constructions, particularly with respect to its ability to operate reliably over a long period of use and its ability to deliver against higher pressures (Without frequent breaking) than prior injectors, I have 35 found as the result of further experiment that the operation and durability of the tube structure may be further improved by the employment of certain additional features constituting the present invention.

40 Injectors are sometimes classified as lifting and non-lifting injectors, respectively, and the advantages of the tube structure of my prior patent were described with particular reference to its use in a non-lifting type of apparatus (al- A.5 though it is equally useful in substitution for the usual tubes of injectors of the lifting type). However, While injectors are thus classified, and while injectors employed, for example, in steam locomotive practice, are quite commonly of the noniifting typen-being located below the level of the Water in the tender tank, yet it is a fact that for best and most certain results, an injector, even in a lccati. is most reliable if it has some cap-ability for llfting or developing suction 55 at the Water inlet.

(Cl. S-267) When an injector breaks, steam enters the water inlet and heats the Water in the feed pipe, and When it is attempted to restart the injector, particularly if the Water in the tank be low, the Vapor, which accumulates in the space above the 5 level of the hot water in the inlet, presses back the Water into the feed pipe so that it is not available to condense the steam in starting, thus causing difiiculty unless a substantial suction action is available to draw out such vapors and pull lo the water into the injector casing as soon as the steam valve is opened. While the tube structure of my aforesaid patent permits delivery against unusual pressures and is effective for longer periods of use than prior injector tubes known to l5 me, it sometimes happens, either through careless operation, continued use after the tube structure has actually begun to wear, or otherwise, that the injector will break more or less frequently, which results in undue heating of the feed water, making restarting abnormally idiicult (as above referred to) and with a progressive increase insuch diiiiculty as the feed water becomes hotter and hotter. 'I'he requisite suction or lifting action may be obtained by the use of an auxiliary lifting tube in advance of the usual combining tube, but ordinarily the employment of such a lifting tube necessitates the provision of a special partition or other support for the tube in the injector casing, and thus a lifter tube can not ordinarily be installed in an injector casing not especially designed for it.

One 'object of the invention is to provide a tube structure embodying the advantages of that of my aforesaid patent but such ythat theY injector may be started readily even with very hot feed water, but without necessitating the Yuse of auxiliaryv controls or undue complication of the injector parts. Y

More specifically, the present invention con- 40 templates the use of a tube structure generally similar to and having all of the advantages of that disclosed in my prior patent, but having in association therewith, all in one unitary device,

a lifter tube designed to furnish the requisite lifting or suction action when circumstances made such action desirable, but without requiring, for its installation, any change in the injector casing or in the steam nozzles or other associated operative parts. 50

In my aforesaid patent it was pointed out that wear of the inner surface of the tube results in ineffective operation and causes breaking and diiiiculty in starting, and. it Was suggested that a selected portion of the tube might be made Cil wear-resistant in order to extend the eiective life and eiciency of the apparatus. However, if one part only of the tube be made wear-resistant, it is found that eventually wear will take place at other points, and in accordance with the present invention, it is proposed to furnish the tube structure with a wear-resistant lining, either integral or in the form of a removable insert or inserts, not only at the point where wear usually first becomes apparent, but, if desired, through-v out the entire length of the passage, including both the combining and delivery tubes, andtalso in the same way, if desired, to make the lifter tube wear-resistant.

Other objects and advantages of the invention will be made manifest in the accompanying more detailed description and by reference to the accompanying drawings, wherein Fig. 1 is a vertical section lengthwise of an injector casing having the improved tube structure constituting the present invention .mounted therein,1a.nd showing the .parts in the .position which they occupy after the injector has started;

' Fig. 2 is af-fragmentary:longitudinally vertical -secton similar toi Fig. 1., but iomitting cert ain elements,'andzwitlithe -parts-inv the position which they 'oocupy'when the injector is being started; '1 3 isan end-elevation lookingfrom the lefthandside of Fig. 1;

1. IFig. 4 isa-fragmentary vertical'isectiori. through 'an injector casing -having a tube' structure of 'slightly modified form mounted-therein;

1=Fig. 5` is a fragmentary-vertical section illustrating a-wear-resistant llifter tube; and

I' Fig. 6 isa-'frag-mentar-ysection, on the same plane asl Fig. 1,--showing-cer-tain ldetails to larger scale;

1 of the drawings illustrates a two-part injector casing comprising the rear member I and `Ythe forward-or deliveryend member 2. The casing'members I- andAZ-are'provided'with flanges 3 and '4; respectively, whichv are clamped together by bolts 5 so as to form a unitary structure. The -rearmember I" ofthe casing is furnished with a ^downwardly directed nipple 6 for-the 4reception 'of a connection I designedA to receive'the'end' of a hose or other suitable conduit leading to the watersupply. A water check valve-'8 is disposed within the .water inlet chamber Ia of the casing, immediately above the delivery end of the passage through the nipple 6, for the purpose of prevent- `ing water from. being driven back intothe sup- .plyj pipe.

1.The.rear member I of the casing. is also-furv .nished with upwardly directed nipples 9 and ila for the' attachment' of steam supply pipes 9X and 9?' respectively, ieading from an injector control valve, for example, of the kind disclosed in my, copending applicationfor Letters Patent .Se- -,rial No. 21,933, filedMay 17, 1935.

[Withinthe rear or inlet end of the casing there is arranged the forcer nozzle i' and, in concentric, relation thereto; the annular priming nozzle I`I.Q AThe rear end'of the forcer nozzle I isV open tothe steam inlet chamber I2 which freely communicates withthesupply pipe 9X, while the rear A,end of theprimingnozzle II is. open to a .steam rinletL chamber.' I3 4supplied with steam by pipe SY. At its extreme rear end the casing is provided .with an attachment T (having. an interior cham- I.ber-which communicates with the water inlet .chamber la) to .which apipe. isconnected lead- .ling upV to a. telltale in the locomotive cab tonotify.the.engineer when the injector'breaks.

The forward member 2 of the casing is fur- ,comprises the rear or combining tube member I3 and the forward or delivery tube member iS. The

member I8 is furnished, adjacent to its smaller end,.with an externally screw-threaded nipple 29, while the member I9 is provided adjacent to its smaller end with` an internally screw-threaded socket 2I wherebythe tube members may be detachably secured together.

The interior of the combining tube converges from its entrance end 22 toward its smaller end while the delivery tub-e flares in diameter from its Ycollectively providing `an uninterrupted passage devoid-'of lateral :outlet'sfrom its entrance end' 22 `to` its '-delivery endl 23.

The passage through the tube structure is substan-tiallylcoaxialfwith acheck valve 24 arranged 'to close arr-opening at the delivery end of the casin-gmember 2, such check valve having a stem 25 :sliding in a guide-carried by a removable cap 26 screw threaded into-an opening in the extreme `forwardnenclofthe-casing member 2, the opening controlled-by` the' check valve 24 being ofvsufdcient 'diameter-to permit removal therethrough of ythe delivery member I9 of the tube structure whenmdesired The -check valve opens into a' Achamber Zlwhich in turn is connected with a pas- SageZBleadingto the boiler which is to be fed.

APreferably the' delivery tubeA member I9 is pro- `vided with a'hexagona'l flange 29 or equivalent means forapplication of a wrench or other appropriate tool;.wherebythe delivery tube may be `screwedronto or unscrewed4 from the combining tubeiwithout disturbingthe latter.

j kIhecombining tube is provided, adjacent to its sm'allerend, with; an lexternal Aannular enlargement-or annulus furnished at-its outer edge witlra flange member SI (Fig. 6) having'nished radial faces32"and33 respectively, which are de- 'signedto'be'clamped in'l'eakproof contact between vcorrlplemental'surfacesStand 35 of the respective flange members 3v and 4.' 'When'tlius clamped in \positiontheannulus Soforms a support for the `tube"structure and a uid-tight partition be- .'tween the inlet chamber Ia and the outlet chamber 2'1. l"The annulus'SIl' is also provided with a rear- Awardly extending,

externally screw-threaded sleeveport'lon' 'with which normally engages c the internally screw-threaded rear end portion of atubularskirt member 3l radially spaced from 'but concentric with the tube member IS and integral-at its forward end with the rear end of a lifter tube member 38, the latter having an internal'passage' which converges forwardly from thefrear end 39 oftheLlifter'tube. This lifter tube embraces the forward end of the forcer nozzle if), being radially spaced from the latter, the forward end ofsaid nozzle preferably being disposed just within. therear. end of the combining tube I 8,

.while the rear end 3Q of the lifter tube is preferablyspaced a short distance forwardly of the forward end of the priming nozzle II. The space between the skirt member 37 of the lifter nozzle and the'exterior of the combining tube member I8 constitutes an intermediate chamber 40. From this chamber one or more passages '4I lead through the annulus 30 in a forward direction and into the rear end of the delivery chamber 2a.

The exterior surface of the combining tube just forwardly of the annulus 30 is preferably substantially cylindrical to form a guide for a sliding annular valve 43, adapted at times to close the passage or passages 4 I. This valve may slide to a limited extent in a front-to-rear direction, being limited in its rearward movement by contact with the annulus 30 and in the forward direction by contact with the rear end of the delivery tube I8.

In accordance with a preferred construction, the delivery tube is provided with a wear-resistant lining sleeve 46 which extends forwardly from the smaller end of the tube and which is adapted to resist the wear which ordinarily takes place quite rapidly at the point where the passage through the tube structure first begins to increase in diameter. Likewise, if desired, the combining tube may be provided with an internal lining sleeve 41 of wear-resistant material. These sleeves 46 and 47 fit in recesses in the delivery and combining tubes, respectively, the inner surfaces of the sleeves constituting the wall of the passage through the tube structure at those points at which they are located, and preferably meeting with a flush joint so that there are no appreciable crevices either at their junctions with each other or at their junctions with the tube members I8 and I9. These sleeves, if eventually worn, may be slipped out of the respective tube members I8 andI9 when the latter are disconnected and replaced by new ones.

As illustrated in Fig. 5, the lifter tube may also, if desired, be made wear-resistant, as'for example by providing the rear end of the skirt 3l with an internally screw-threaded nipple portion 48 which receives a screw-threaded nipple 49 forming the forward end of the lifter tube Ia, the latter with its nipple portion 49 being of wearresistant material. Instead of employing wearresistant sleeves 4B and 41 it is contemplated that either or both of the tube members I8Y and I@ may be made wholly of wear-resistant material and it is further contemplated that instead of making the entire lifter-tube, as shown in Fig. 5, of weareresistant material such tube may be provided with a removable wear-resistant lining sleeve in the same way as the delivery and combining tubes illustrated in Fig. l.

In the arrangement illustrated in Fig. 4 the casing I x is of unitary construction (not divided into two parts like that of Fig. l) and has within it the inlet chamber Ia and the delivery chamber 2a. However, in this modified arrangement the wall of the casing is provided with an interior flange 5I) which is internally screw threaded for the reception of an externally screw-threaded annulus 5I carried by the combining tube, the flange 50 being furnished with a forward, radial, nnished surface 52 for leak-proof contact with a radial rear face of a flange portion 53 of the annulus 5I. The annulus 5I is furnished with passages 54 leading from the intermediate chamber 4I) forwardly into the delivery chamber 2a, and these passages are controlled by the sliding anv nular valve member 43=ab similarto the valve member 43 above described.

The operation of the device illustrated in Fig. 1 is substantially as follows: When the injector is to be started and steam is first admitted preferably in gradually increasing quantities through one or the other of the .nozzles Il) and II, the

lifter tube 38 immediately exerts a substantial suction effect effective to draw out from the inlet chamber Ia any vapor or air which may have accumulated therein, or if the water in the supply be low, to induce the ilow of water into the chamber Ia. During the initial entry of steam into the injector any back pressure which develops, and Which would ordinarily tend to force water and steam back into the. feed pipe, merely opens the valve 43 so that the steam and/or water is freely delivered through the passages 4I directly into the delivery chamber 2a and thence through the overflow passage I5. When the injector has thus been properly cleared of air and vapor, and as soon as the inlet chamber Ia has been filled with water so that a proper condensation of the steam from the nozzle takes place within the combining tube, pressure is built up within the passage through the combining and delivery tubes sufficient to open the check valve 24 and force water into the chamber 2! against the boiler pressure. As soon as the normal operation commences, the pressure in the delivery chamber 2a causes the valve 43 to be closed and thus the injector continues to operate, the operator regulating the amount of water by proper manipulation of the steam control valve (not shown) If at any time it became necessary to repair or replace any of the tube members I8, I9 or 3B, it is only necessary to disconnect the casing members I and 2 by removal of bolts 5, whereupon the entire tube structure may be removed as a unit from the casing. Any one of the tube members may then readily be separated from the others for inspection, repairs, or replacement, and the parts all reassembled, without necessitating any disturbance of the setting of the nozzles, inlet valves, water supply pipe, or other parts associated with the rear member I of the casing.

On the other hand, the delivery tube member I9, which is usually the rst to wear, may be removed and replaced, without disturbing the other members of the composite tube structure, merely by removing the check valve housing 26 and the valve 24, and by means of a suitable tool disengaging the tube member I9 from the member I8, or reengaging therewith.

In the construction of Fig. 4, the entire tube structure may be removed as a unit through the .check valve opening, Without disturbing the cas'- 1 ing or any of the connections leading to or from the latter, and without interference with the nozzles.

While certain desirable embodiments of the invention are herein illustrated by way of example, it is to be understood that the invention is not necessarily limited to the precise details shown, but is broadly inclusive of all equivalents as defined by the appended claims.

1. A tube structure for use in injectors, said tube structure comprising a-combining tube mem ber, a delivery tube member, and a lifter tube member, all of said members being in axial alignment, the combining and delivery tube members being normally united at their smaller ends, the combining tube having an external annulus provided With a substantially cylindrical, externally screw-threaded portion, the lifter tube member having a tubular skirt coaxial with and embrac- T ing but radially spaced from the combining tube thereby to form anY intermediate chamber beltween said tube members, the forward end of the skirt member being screw threaded for engagement with the cylindrical portion of the flange and the latter having a passage leading forwardly from said intermediate chambeigand valve means for closing said passage.

2. A tube structure for use` in injectors, said tube structure comprising a combining tube member, a delivery tube member. and a lifter tube .member, said members being in axial alignment,

the combining and delivery tube members being normally united at their smaller ends, the lifter tube member having a tubular skirt portion coaxial with and embracing the rear portion of the combining tube but radially spaced from the latter to form an intermediate chamber, the forward end of the skirt portion of the lifter tube member normally being united to the combining tube member, means providing a passage leading from the intermediate chamber beyond the forward end of the sln'rt portion, and valve means for closing said passage.

3. A tube structure for use in injectors, said tube structure comprising a combining tube member, a delivery tube member and a lifter tube member, said members being in axial alignment, the combining and delivery tube members being normally united at their smaller ends, the combining tube member having an annular-external supporting flange designed to form a transverse leaktight partition across an ejector casing and to position the tube structure in said casing, the liange having a substantially cylindrical externally screw-threaded portion, the lifter tube member having a tubular skirt which embraces the rear part of the combining tube and which has screw-threaded engagement with the cylinrical screw-threaded portion of the flange, said ange having a passage therethrough, and Valve means for closing said passage.

4. A tube structure for use in injectors, said tube structure comprising a combining tube member, a delivery tube member and a lifter tube member, said members being in axial alignment, the combining and delivery tube members being normally united at their smaller ends, the combining tube having anl annular external positioning ilange designed to form a transverse partition across an injector casing and to position the entire tube structure in said casing, the lifter tube member having a tubular skirt portion embracing the rear part of the combining tube member and forming therewith an intermediate chamber, the iiange having a passage leading forwardly from said chamber, and an annular valve coaxial with the combining tube member and movable axially of the latter to close or uncover said passage.

5. A tube structure for use in injectors, said tube structure comprising a combining tube mem- -er, a delivery tube member and a lifter tube member, said members being in axial alignment, the combining tube having an integral annular supporting flange adjacent to its smaller end, said flange being designed to form a transverse leaktight partition in an injector casing and having a surface designed to be clamped firmly against a complemental surface of the casing, said flange having a rearwardly extending externally screwthreaded sleeve portion, the lifter tube having a tubular skirt screw threaded to engage said sleeve portion of the ange and which houses the entrance end portion of the combining tube and which is radially spaced from the latter tube to form an intermediate chamber, the flange having passages through it leading'forwardly from said chamber, an annular valve coaxial with the combining tube for closing said passages, and means annee? .constituting a guide on which said annular valve Amay slide toward and romthe ange.

6. A tube structure for use in injectors, said tube structure comprising a combining tube member, a delivery tube member and a lifter tube member, the combining and delivery tube members being normally united at their smallerends, thel combining tube having an integral annular supporting ilange adjacent to its smaller end, said flange beingv designed to form a transverse leak-tight partition' in an injector casing and having a surface designed to be clamped'rmly against a complemental surface of the casing, said flange'havinga rearwardly extending sleeve portion, thelifter tube having 'a tubular skirt :which ts over and is united to said sleeve portion and whichlhouses the entrance 'endportionsof the combining tube 'andicooperates Ywith Vthe 'latter tube to form an intermediate chamber, the ange having passages through it leading forwardly from said chamber,l an annular valve coaxialiwith the combining tube for 'closingfsaid' passages'and means constituting a guide on which saidannular' valve may slide toward and from thefflange, said valve being removable by' separation ofthe combining and delivery tubes.

'7. A tube structure for'use in' injectors,` said tube structure comprising'a combining tube member, a delivery tube member and a lifter tube member, said membersI being in axialY alignment, the combining tube having an integral 'annular supporting flange adjacent to its smaller'end, said ange being designed to form a transverseleaktight partition in an injector casing and having a surface designed to'be clampedrmlyragainst a complemental surface of the casing, said flange having a rearwardly-extending externally screwthreaded sleeve portion, the lifter tube having a tubular skirt which houses the entrance end portion of the combining: tube and which cooperates with the latter tube to form an intermediate chamber, the ange having passages through `it leading forwardly from said chamber, an annular valve coaxial Withthe combining tube for closing said passages, and means constituting a guide on which said annular valve may slide toward and from the ilange, the smaller end of the delivery tube normallyconstituting a limiting stop for said valve.

8. A tube structure for use in injectors,-said tube structure comprising a combining tube member, a delivery tube member, and a lifter tube member, said members being in axial alignment, the combining and delivery tube members being separably united at their smaller ends -and being devoid of lateral outlets, the lifter tube member having a tubular skirt portion coaxial with a'nd embracing the rear portion ofthe combining tube and being radially spaced from the latter to form an intermediate chamber between the inner surface of said skirt portion and the outer surface of the combining tube member, the forward end of the skirt portion of the lifter tube member being separably united to the combiningtubemernber, certain at least of said tube ymembers having wear-resistant innersurfaces, means providing a passage leading from the intermediate chamber to a point beyond the forward end of the skirt portion, and pressure actuated valve means for closing said passage.

9. In combination in an injector having an elongate casing provided at one end with an inlet chamber housing a steam nozzle and having a delivery chamber adjacent toits opposite end, a tube structure comprising a combining tube member.

a delivery tube member, and a lifter tube member, said members being in aXial alignment, the combining and delivery tube members being normally united at their smaller ends and being de- Void of lateral outlets, the tube structure comprising an annular external positioning flange which forms a transverse partition across the injector casing and which positions the entire tube structure in the casing, the lifter tube member having a tubular skirt portion embracing the rear part of the combining tube member and forming therewith an intermediate chamber, the iiange having a passage leading forwardly from said intermediate chamber to the delivery chamber, and an annular valve coaxial with the combining tube member and movable axially in response to varying pressure conditions within the injector casing to close or uncover said passage.

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