US1340074A - Superheater - Google Patents

Description

I. S. NICHOLS.

VSUPERHEATEIL APPLICATION AFILED MAY 12,.'1915. Patented May 11, 1920.

-5 SHEETS-SHEET Q J. S. NICHOLS.

SUPERHEATER.

APPLmATloN FILED MAY12, |915.

1,340,074. V Patented' Mayu, 1920.

5l SHEETS-SHEET 4.

J. S. NICHOLS. /SUPERHEATEIL 1 Y K .APPLlCATlON FILED MAY l2 1915.

1,840,074. l Patented May'11 ,1920. I 5 SHEETS-SHEET 5 f f 7/ 1%/2 Y Y l l 67 UNITED STATES PATENT OFFICE.

JAMES S. NICHOLS, 0F ATLANTA, GEORGIA.

sUPERHEATER.

' Application led 'May 12,

To all 'whom t may concern:

Be it known that I, JAMES S.` NICHOLS, a citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented new and useful Improvements in Superheaters, of which the following is a specification.

My present invention relates to improvements in steam superheaters and is especially adapted for use -in connection with locomotive boilers.

The primary object of the present invention is to provide certain improvements in superheaters of l the class shown and described in my prior application, Serial No. 871,930, filed November 13, 1914, which embodies a valve, a fire-box superheater and superheater units within the boiler flues and which also embodies means whereby saturated or superheated steam may be used separately or mixed and a circulation of superheated steam is maintained through the superheater, steam from the superheater being returned to the boiler when the same is not being used.

The present invention provides a valve of novel and improved construction for controlling the iow of superheated steam either to the engine cylinders or to the boiler when superheated steam is not being used; it provides improved means for introducing the saturated steam from the boiler to the lire-box superheater unit to preventback-flow of superheated steam from the superheater units in the flues; it provides means for flooding the superheater in firing up the boiler to prevent burning or damage to the superheater structure before the generation of suiiicient steam to protect the superheater; it provides means whereby the supply of all saturated steam to the superheater can be cut off to enable repair or replacement of parts of the superheater while the boiler is under steam pressure; and it also provides superheater units ofY improved construction for the boiler flues whereby the construction ,and repair thereof are facilitated.

To these and other ends, the inventionconsists in certain improvements, and combinations and arrangements of parts, all as will be hereinafter more fully described, the novel'features being pointed out particu- Specicaton of Letters Patent. PatentedMay 11, 1920.

1915. seriai No. 27,638.'

larly in the claims at the end of the speciication.

In the accompanying drawings Figures 1 and 2 represent longitudinal sections of the front and'rear portions of a locomotive boiler equipped with a superheater embodying the present invention.

Fig. 3 represents a vertical section of the valve which controls the flow of superheated steam from the superheater, together with the pipe' by which the superheated steam is returned to the boiler when superheated steam is not being used.l

Fig. 4 is a top plan view of the valve with the top cover removed. A I

Fig. 5 represents a section on the line 5--5 of Fig. 3.

Fig. 6 represents a section of the valve on the line 6 6 of Fig. 3. Fig.l 7 represents a cross-section of the superheated steam return pipe showing one of the clamps by which it is attached either to the valve or to the forward flue sheet.

Figs. 8 and 9 are detail views of the improved head for the pipes of the superheater unit. A

y Fig. 10 represents a transverse section superheater element or unit therein and provided with a spacer between the pipes of the superheater unit and a clamp for binding together the pipes and supporting them centrally within the flue'.

` Fig. 11 is a detail view of the separator or spacer for the pipes of the superheater unit.

Fig.. 12 is a transverse-vertical section through the smoke boX, showing the valve casing or header in elevation, and with the superheated steam pipes connected therewith partly broken away.

Fig. 13 is a plan view of the header and associated parts shown in Fig. 12.

Similar parts are designated by the same reference characters in the several views.

The present-invention provides improvements in superheaters which are capable of use either in whole or in part in connection with steam boilers of various types. These improvements are especiallyapplicable to' l through one of the boiler flues showing -a` in detail. It is-to be understood, however,

the end ofthe specification.

In the present instance, the boiler, which "is of the locomotive type, comprises the cylindrical or barrelportionl, the smoke- 10 box 2, and the re-boXB, fire tubes, or flues 4 extending longitudinallywithin the cylindrical portionof theboiler and forming passageways for the products of combus- V tion leading from the fire-boxto the smokef box. -Theendsofthe fines or Ifire tubes are fitted into fthe front-'and rear tube sheets 5 and 6, respecti,r1/ely.;"v order to provide the maximumfspace. for'the superheater units openings in thejrear flue sheet 6,the'rear ends of the. flues .are preferably swaged or4 otherwise reduced, .as at 7, so thatthe fines be of la size 'to amply accommodate the -superheaterrnita butthe openings fo rfthes'e` fines inthe rear tube sheet 6 maybeof'the usual Y Q The" `a numb-er ot superheater units which lare contained vin heated gases flowinglongitudinally within i some of the fluesor fire tubes of theboiler,

the same being inserted into the lues fromk E the forward ends thereof. Preferably, yand "fas shown, each superheaterv comprises - pipes 9 and 10 in the present instance) a number of present instance. Two of these pipes (the have theirrear ends threaded into. open` vings 1l and.l2 which are formed in a head 13, Athe latter being composed preferably of a casting and having a return bend or channel 14 formed therein and establishing com- -lnunication betweenthe adjacent ends of the tubes or pipesand 10. Thenead 13 an openlng l5 which is straight and eX- lng. v The pipe 8 is connected -to one of the othervtwo p'pes Aof thesuperheater unit at Y the forward endof the unit, it being-shown 4connected to the 'pipe 9 in the presentinvstanceby the return bend 16. Ihe forward' fend of the remaining pipe 10 isconne'cted y by a bend 17l to the superheated slteamcontrolling valve 18. l

The pipes or`tubes composing leach superheatenunit are held in properly spaced relation t'o-permit the circulation of the heated gases between them by separators or spacersv 19,'th'ese- 'spacers being placed at suitable intervals longitudinally ofthe su- 'perheater unit. In using three pipesfor tubes for each-superheater unit, each spacer will have a set of three segmental recesses 20 in its periphery Vin which-the `respective pipes or tubes ofthe superheater unit are lheater unit.

pipes or 'tubes .`8, v9f and 10,1 three pipes or tubes beingshown .in the tends therethrough from end to end, andv 'the pipe 8 is slidingly fitted into this open-v seated whereby these pipes orftubes will be separated or held -inffprop'erly spaced relation. The spacer or separator. may also be pipes or tubes, the sectionsfof the 4 band being' united by rivets 23 or equivalent means, and feet `or lugs =24H are formed -at the apices of the band to; engage the inner wall of the flue whereby, the superheaterunit' is supported and appropriately centered with-A in the flue, thus avoidlng obstruction to the passage ofthe heated'gases andinsuring uniform action of the heat `upon the super- In. order toavoid burnin or other injuryto the corners of the'hea 13` Where the pipes 9 and 10are inserted thereun, due to the action of thehighly' heated fgases, laterally projecting enlargements 25 arefo'rmed 'at opposite 'sidesofthe head 13 in rear of suchvcorners whereby the highly theliue' will be deflected and .hence preventedfrom striking directly against 'these corners ofthe head. y

Apulling the same forwardly therein, 'a suitfor example, an ordi- -105 able coupling 160, (as, nary 18()o elbow) being providedl forvthe pipe 8 atthebend 16 therein, 4the head 13 sliding longitudinally on the'pipe 8, .and the forward en d of the pipe 8 which remains"- within the flue may be connected byv a suitabl'e union and a section of pipe of proper' length to the coupling-26 and thencedirectly to. the lsluierheated steamn controlling valve l8. To facilitate connecting the 4forward ends of the superheater-units to the valve 18 115 and to also allow for Vexpansion and contracpiping and other parts, ball tion of the joints 26 may be provided, as shown.

The superheate'r shown inthe present instance not only comprises the superheater units containedin the boiler lues, but the superheater units is also provided in the firebox. of the boiler. This fire-box superheater comprises outer and inner shells 27 and 28, the top and forward sides ofwhich are preferably horizontal and vertical, respectively, and the rear Walls of these shells are prei"- erably inclined in order to accommodate the fire-box superheater to the firing of the boiler, as well as to insure the most efficient 136 action of the heat upon this superheater. The space 29 betweenv the outer and inner shells 27 and 28, respectively, is a Water space, and it is connected to receive Water from the Water space of the boiler by a suitable pipe 30, and to return this Water from the space or chamber 29 to the water space of the boiler by a suitable number of pipes' boxsuperheater unit by a pipe 34 which leads from the steam dome 35 and is preferably provided with a manifold 36 and a suitable number of branch pipes 37 which lead therefrom and through the outer and inner shells 27 and 28, discharging saturated steam from the steam dome into the steam chamber These saturated steam supply .pipes 37 vare preferably extended downwardly to substantially' the bottom of the steam chamber 33 in order that the saturated steam will be introduced at the bottom of this chamber, and rising therein will maintain, in the bottom of said chamber, a body of saturated steam which will prevent the backlow of the relatively lighter superheated steam from the superheater units in the boiler flues. In order to increase the efficiency of the boiler and at the same time protect the fire-box and superheater from becoming unduly heated, a water-jacketed steel arch is placed in the fire-box of the boiler and between the tire therein and the rear side of the fire-box superheater unit. rl`he water-jacketed steel arch in the present instance comprises a shell 38 having a water chamber 39 which is connected bythe pipe 40 to receive water from the water space of the boiler` and it is connected b v the pipe 41 to the water space of the boiler at a relatively higher point to return the water, but heated to a higher temperature, to the water space of the boiler. The water-jacketed steel arch is preferably formed with an opening 42 through which a portion of the heated gases may pass and become uniformly distributed around the fire-boX superheater. Also, a portion of the water heated in the chamber 39 is preferably conducted into the Water space 29 of the fire-box superheater, pipes 43 and 44 being shown connecting the chambers 29 and 39 for this purpose.

In firing up the boiler, it is preferable or advisable to flood the superheater system with water to avoid burning or unduly heating the elements or units thereof before sufficient steam has been generated in the superheater to protect 'such parts. To enable this to be accomplished, a pipe 45 is provided which connects With one of the pipes 37 leading to the steam chamber 33, and the pipe'45 is connected at 46 to the water space of the boiler, the flooding of the superheater with water being controlled by a valve 47 which valve, however, is closed during the normal operation ofgthe boiler under steam pressure. Means is also provided for cutting off the supply of all steam to the super heater should such become necessary owing to damage of any part of the superheater; As shown, a valve 48 'is provided in the saturated steam supply pipe 34, this valve having a handle 49 which may be manipulated toclose the valve from the exterior of the boiler shell. Byclosing the valve 48, the supply of all saturated steam to the superheater is cut off and it is thereby rendered possible to remove or repair different parts of the superheater, and particularly the superheater units in the boiler flues, while the boiler Lis under steam pressure. In the normal operation of the boiler, however,

this valve 48 is open;

Saturated steam may be admitted to the engine cylinders by 'the dry pipe 50 under control of the throttle 51, as is usual. The pipe 50 is provided, however, at a suitable point, preferably in tliesnioke-box of the boiler, with a fitting 52 to which the superheated steam controlling valvevlS is connected. This superheated steam controlling valve, according to the present l`invention, comprises a casing 54, one wall 55 of which is provided with openings into which the"- pipes 17 leading from the superheater units in. the flues are fitted, the casing being formed with a superheated steam chamber 56 into which the superheated steam from the flue units discharges. The valve casing is also formed to receive a valve which pei-, forms the function of controlling the return of superheated steaml to the boiler andthe flow of superheated steam to the engine cylinders. ln the construction shown. the valve has a cylindrical portion 5T which is reciprocable in a correspondingly formed portion of the valve casing and is provided with a transverse port 5S which is movable into and out of communication with ports 59 and 60 formed in the valve casing. A vent 6l maylead from one end of the valve to the port 58 to avoid a compression or vacuum at such end of the valve as the latter is reciprocated. The valve also has a portion to control the flow of superheated steam to the engine cylinders. such portion in the present instance comprising a head 62 having a conical part 63 to coperate with a conical seat 64 in the. valvc casing, and a cylindrical sleeve 65 extends below the l conical portion of the head and lits closely within a cylindrical portion 66 of the valve v heated steam, or both, to the engine cylin ders. The super-heated steam controlling rvalve has a rod 70 attached thereto, and thisv rod extends through a stuiing-box 71 in the'v lid or cover '72 of the valve casing 18, and suitable means is provided whereby 'the rod '70 and consequently the superheated steam I' controlling valve may be operated from the cab of the llocomotive or from any otherv suitable point. In the present instance, a

` bell-crank lever 73 is provided,.which is "pivoted at 74 and is connected by a rearwardly extending rod 75 to athrottle'leverl 76, thelatter being pivote'd'at 77 and .provided with a suitable locking 1- sector 78 i i whereby the superheated steam valve `may bep OPE-ned t@ any suitable point or closed and retained in any of these desired positions. rl`he port 60'in the valve casing 54 with the respective seat-s.

Xs connected to return-superheated steam to the boiler when superheated steam is not.

being used. As shown in Fig. 3, s upe'r heated steam is returned to the boiler by'a return `pipe 79 which Jforms a connection between thevalve casing'lll and the tube sheet 5 and terminates atthe latter. In Figs.. I and 2 is shown' a Apipe 780 leading rgm the forward tube sheet 5 to the steam dome 35,

and connectedat its forward end with the valve casing '54 by a short return pipe corresLioiid'ing to the pipe 79. The means for connecting the return pipe with the valve casing vand tube sheet are preferably 'such as to facilitate the fitting or'v said pipe and also toallow for variations in alinement of the parts due to contraction andexpansion or any other .influences or strains to, which they, may be' subjected in use Thus, as shown-most clearly in F ig. 3, each end of the pipe 79 is formed with a spherical surfale 8() to engage a correspondingly formed seat in the tube sheet 5 and in the valve `(Taslng -l surrounding the port 60, and devices are provided vfor clamping these ends of the pipe 79 into steam-tight engagement As shown, each end otl the pipe 79 has an enlargement 8l, and a pair of yoke-shaped plates 82 and 83 isprovided, these plates having openings 84- and 85 which enable the plates to be slipped over the pipe 79,'and after the plates-are applied, they are relatively rotated to carryY the openings 84 and 85 out of register, as Yappears in -Fig. 7. One of the plates (the plate 82 in the present instance) isfalsol preferably provided with flanges 86 which are adapted to overlap certain edges of therl sition shown in full lines in Fig. 3, to Gaus@ plate 83 to prevent relative rotatio/n hetW//e/en them after they have been properly applied to the pipe 79. Bolts, 87 extend through registering openings Ain'the corners of the plates 82 and 83 and serve to clamp the'ends of the pipe 79 in position.

The length of the superheated steam return pipe, and the precise details of some of'the other parts of the connection, will, of course, vary considerably according to A the requirements. Thus, there is shown in Fig. 3 a construction suitable for use in a stationary or other boiler installation involving a relatively long distance or space in the smoke box between 'the boiler iiues` and the smoke stack. I n1thecaseof`a locomotive boiler, such as 'iS/shown inv Fig.

.1, this space is relatively' short, and the design of. the-connections will be A correspondingly modified to correspond to the other 'dimensions .of the structure. Also, as above'stated, in the case of a locomotive boiler provision is preferablyy made fordelivering thereturned superheated steam to A vthe steam dome instead-of dischargingfthe 4 y forWard// tube sheet, Vas in the case of a stationar same directly intothe boiler at the y boiler.

The' Acontrolling A,valve inthejcasin'g is operative to direct superheated steam from the chamber 56 -to the-boiler and alsoto di- 'rect and throttle the How of superheated steam from vsaid chamber. to', the outlet port67.

- When '-superheated -steam` is not being used, the valve occupies :the'position shown in Fig. 3, the supply ofjsuperheated steam tothe engine cylinders-.being then cut off, and the,- superheatedA s team: entering the chamber 56 from. gth'eg superheater .passes throughv the ports V 58,59 and GQ which are then in register and returns -tothe boiler by'way of the'` pipe79. vThe full 'quantity oi supe-rheate'drsteam is `s upplieduto -t'he en# ginecylindersby raising the valve' to its uppermost'position; which carries the valve port V58 out of register with the super-heated steam port 592 and the return por-tor passage 60, and'ucarriesthe sleeve 65toa. point above the valve sea-U64., The return of. superheated4 steam to. theiboile'risat this time cut off, and the superheated steam is admit'- x intermediate position ofv the valve, shown heatedsteam port 59andreturn port or passage 6f),'but also with the chamber 68.and

. consequently -with the outletfport 67. y When,

therefore,v the valve is' moved downwardly from its uppermost position into. the :po-A

ted from the-chamber 56 through the? opening in the'valve seat y64l to the chamber 68 'and thence to the outlet :port 67, from which it passes int'f the fitting "52 and thence'v through the;A pipe 69 fto :the engine.' Injan` the head 62 and sleeve 65 to close communication between the chamber 56 and outlet port 6T, the valve port 58 immediately opens c'onimunication between the chamber 56 and both the outlet port 6T and return passage 60, and thereafter, as the valve is further depressed, closes communication between the chamber 56 and outlet port 6T and fully opens communication between said chamber and' the return passage 60 alone. It will thus be seen that in one extreme position of the valve superlieated steam is admitted to the outlet and cut, off from the boiler, that in the other extreme position siiperlieated steam is admitted to the boiler and cut off from the outlet, and that, as the valve is shifted from one extreme position to the other, communication fiom the supeiheated steam chamber is maintained with both the outlet port and the return passage until one or the otheris fully open.

In the operation of locomotives, it is desirable or necessary to start and stop the locomotive by the use of saturated steam, and to use saturated steam 'as a lubricant for the cylinders and their working-parts. In such' cases, the locomotive may be started by admitting saturated steam to the cylinders by opening the usual throttle 51 in the ordinary way,l the siiperheated steam controlling valve being then set so as to return the steam circulating through the superlieater to the boiler. Superheated steam may then be admitted to the engine cylinders by opening the valve 18 which cuts off the return of superheated steam to the boiler and permit i the s uperheated steam to flow into the pipe 69 through the fitting 52. In cases where it is desirable oi' advantageous to use a mixture of saturated and superlieated steam, the saturated steam controlling throttle 51 may be opened more or less, admitting saturated steam to the engine cylinders, and the superlieated steam controlling valve 18 may also be opened to an extent to admit a suitable amount of superheated steam to 'the engine cylinders. Of course, the locomotive can be -driven by saturated steam alone or by superheated steam alone, and when saturated steam alone is used, a circulation of steam is-inaiiitained through the sul'ierlieatei', thus utilizing the full heating effect of the superheater in the generation of steam and avoiding damage `or injury to the superlieater. A safety valve 88 may be fitted in4 the cover T2 of the valve 18 to relieve any eX` cessive pressure that maybe developed in 'the' superheater.

I claim as my invention 1. In combination with a steam boiler and a superheater, a casing having a chamber to receive steam from the superheater, a

passage for conducting superheated steam from said chamber to the boiler and having a port for admitting superheated steam from said chamber to an outlet for use, and a valve having a port to coperate with-said passage for conducting superheated steam to the boiler, and a head to control and throttle the How of superheated steam from said chamber to said outlet, the valve beingoperative to first open communication between said chamber and said passage and to subsequently close communication between said charnbe and said poit when the valve is shifted.

2. The combination with a steam boilei' and a superheater; of a casing having a chamber to receive steam from the superheater; a superheated steam port communicating with said chamber, a passage for conducting superheated steam from said chamber to the boiler, and an outlet port for admitting siiperlieated steam from said chamber to an outlet for use; and a valve having a port movable into and out of communication with said superheated.- 4steam port and adapted to communicate with both steam fiom said chamber to said outlet port when said valve port is out of communication with said siiperlieated steam port.

3. The combination with a steam boiler and a, superheater; of a casing having a chamber to receive steam from the superheater, a passage for conducting superheated steam from said chamber to said boiler, and an outlet port for admitting superheated steam from said chambei to an outlet for use; and a valve having a port adapted to open and close'communication between said chamber and said passage alone or between said chamber 'and said passage and outlet port simultaneously; said valve having also a head adapted to open and close communication between said chamber and said outlet 4. The combination witha steam boiler and a superheater; of a casing havinga chamber to receive steam from the superheater, a -passage for conducting superlieated steam from said chamber to said boiler, and an outlet port for admitting vboiler and to a delivery outlet for use, said means including a-steamcontrolling valve comprising a casing formed with 'a cylindrical seat and also a conical seat'and having ports controlled by thereSpeCtVeseats and adapted to establish communication re-v spectively between the 'superheater---- outlet -and the boiler and between the superheater' outlet and the delivery outlet, and a .reciprocatory 'valve member having a-cylindrical portion operative in the cylindrical seat and having aport'to coperate with the port respective to said seat and also having a.

conical portion coperative with the conical seat.

6. In combination with a steam boiler andv a superheater, means for directing superheated steam Ifrom the superheater to the V boiler and to a delivery outlet'for use, said means including a steam controlling valve comprising a casing provided with a cylindrical seat and also a conical seat and having ports controlled by the respective seats,

said ports being adapted to communicate re-v spectively with the steam space of the boiler and with the delivery outlet, and both ports being in communication with the outlet of -the superheater, and a reciprocatory valve member having a cylindrical portion oper-- ativein the ,cylindrical seat and provided with a port to coperate with the port respective to lsaid seat and also having a conical portion coperative/With 'the conical seat, and a cylindrical sleeve adjacent to said conical portion and operative to prevent oW of steam through said conical seat until the port in the cylindrical seat has been closed.

7. The combination With ay boiler, of a superheater comprising superheater units for the boiler flues and a rebox superheater unit having a steam chamber positioned opposite to the rear ends of the lines and connected to the superheater units as a header therefor, and means for conducting steam from the boiler to the steam chamber in the irebox superheater, said means comprising `a pipe extending doWnWardlyf through the vto'p of said chamber to a point at or near the bottom thereof.

' 8. A superheater unit comprising superheater pipes, and a head containing a return bend passage to which the ends of cer- .t'ain of said pipes are connected and having nesses.

JAMES S. NICHOLS. lVitnesses CHAS. S. HYER, CHAs. A.r RoWE.

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