US1905739A - Superheater - Google Patents

Description

H. B. OATLEY April 25, 1933.

SUPERHEATER Filed April 20, 1931 2 Sheets-Sheet l m. a NIJ Nu Q, a Nw m ww Sv QN *N E n N\ f. NN Wr W N lx. nu QM. Nm, un @$5 NN April 25, 1933. H. B. OATLEY v 1,905,739

SUPERHEATER Filed April 20, 1931 2 Sheets-,Sheet 2 INVENTOR HenryB O alley.

ATTORNEY HENRY 1B. OATLEY, OFGREAT Patented Apr. 25, 1933 UNITED STATES PATENT o NECK, NEwYoax, AssIGNoa 'ro :1HE PANY, or NEW Yoan, N. Y.

SUPERHEATER Apliiication med April 2o,

` MyY invention relates to i're-bo-x superheaters and more particularly to superheaters installed in hre-boxes of locomotive type boilers .equipped with so-called arch tubes. The advantages' of radiant type super-` heaters have been recognized insofar as economy of spacei and material arerconcerned, especially wherea high degree of'superheat is desired, but it has proven difficult to pre* vent the units of radiant type superheaters from burning out. These `diflicultie's are particularly serious in a locomotive type boiler where the ordinary rate of combustion per'unit volume is high.

`It' is an object of the present invention to provide a superheater having, at least in part,radiant type characteristics, and adapted for `use in the combustion space of locomotive type boilers.

'n 4Further objectsand advantages of my invention will be clear to vthose skilled in the art from the following description of a given embodiment of the'invention taken in p, connection with the accompanying drawings in which: Y

Fig. liis a vertical central `longitudinal section throughl a'rear portion of an arch type fire-box in a locomotive type boiler.

Fig. 2 is a half-section 'of a boiler illus-V trated in Fig. 1, taken onthe vline 2 2 and looking in the direction of the arrows.

Fig. 3 is a transversesection of the boiler illustrated in Fig.'1,takenon the line 3--3 and looking in the direction of the arrows;

.. tubesare run from the water leg rearwardly and upwardly above the grates or burners and connectedinto therear water leg.` Ordinarily, arch brick are supported on the lower andforward portions of the arch tubes lin such-locomotives so as to form a baffle. In accordance with my invention, superheater 1931. serial No. 531,379.

elements are` run along the'uppersurface of the baffle formed by the arch bricks. f

'In Figs. 1, 2 and 3, I have illustrated aV locomotive rboiler 10 having smoke tubes 12,

a forward water leg 14, and a rear water leg 16, respectively, as the front and-rear ends of the fire-box 17. l Extending rear-y" wardly and upwardly between the- water legs 14 and 16 and running above the grates or burners are arch tubes 18, 18. Extendeo ing across the fire-box 17 forward of the grate or burner space is a beam 20 above which is a fire wall 22, preferably of vlire brick, and extending up to the plane ofthe arch tubes 18. The vfuel is burned in the space 24 between the firewall 22- and the rear face of the fire boxfin accordance with the common practice. On the arch tubes 18 are'arch brick 26, 26 which may be of any usual or desired type. `rIhe fire wall l22 is 7o spaced rearwardly from the forward water leg 14 enoughto permit the insertion of the ends of superheater units between-the wall and the water leg. In the arrangement shown, the means for leading steam t'o and 75 l from the superheate'r' units comprisesY a header 28 which extends transversely of the boiler 10 just below the level of the beam 20 and between such beam and the water leg 14. Superheater units '30, 30 are con-` 8K0 nected to the header 28 and extend upwardly forward of the wall 22 and then rear-` wardly along the upper surface of the arch formed by the brick 26. Preferablyv `the rear ends 32 of elements 30 are protected 85 from the scouring action of thehot gases kin the fire-box by specialarch brick 34, 34,

the upper ends 34a of which are curved forwardly above the rear upper kends 32of the units 30. It will be seen that the units 30 not only receive heat by radiation Vfrom. the combustion of'gases in thecombustion space above. the arch'but also receive a cer-l tain amount of heat'by direct contact with the gases and that the undersurfaces of the elements 30 receive heat by radiation direct-V ly through the fire brick 26. The heat absorption by units 30 is therefore quite high per unit area and the total area of these units .can be small in proportion tothe SUPERHEATER comziv amountl of superheat added by them to the steam. However, to reduce the rate of depreciation of units 80, I prefer that they lie almost entirely below the level of the rear upper end of the arch brick 26, whereby the convection heat flow to units 30 is kept low.

lVhile the rate ofvheat absorption bythe units 30 is high, in a great many cases it is not convenient to design the locomotive with V longfenough-lire-box'so that all the superheating surface can be placed above ytheY arch. I have therefore illustrated in Fig.

l, besides the superheating surface in the elementsjatthe rear-of the tube sheet, I prefer tomake the-header 28 so that it can serve both lgroups of elements 30 and 36. vAs illustrated, hcader 28 is connected by flanges 4 O5- 4Q-to the mud ring 41 and to the beam 20 and has two internal webs 42and 44 respectively which divide the header into three longitudinal chambers. The forward chamber of header 28-is indicated on the drawings by reference character 46, the central cham.

ben` by character 48 and the rear chamber by character 50. Chamber 46 is connected through an. inlet-52 and by k.a ,-pipe not shown, to{the interior of the boiler.Y Steam which has been introduced into the chamber 4(5passes thence into the` units 36 and back into the chamber 48. From thechamber 48 steam fpasses into the units j30.and then backv into the chamber -50 from which itymay be taken through an outlet 54j to the engine throttle -by a pipe, not shown. Preferably the endsofgthe units 80 and 36 are clamped toseatsjin the top wall o f header 28 by means of clamps `56, 56 and bolts 58, 58, bolts 58 extending down through the webs 42 and 44 below .the lower v face of the yheader 28 to provide room for nutsl), 60. l

Arrangement shown inFigs. 4 and 5 is similar to/that shown in Fig. `l with the eX- ception that the elements above the :arch brick arey arranged in y-a slightly different manner. In the formsfshown in Figs. 4

and y5, elements 30, 30 do not lie wholly in vertical planes, but are bent so .that their heat absorbing portions lie in a plane Vparallel, or substantially parallel, to the surface off-thc arch. They preferablyare covered more or less by tiling 62 to .prevent them from receiving heat by convection, the elements 30` having van entirely-radiant. type characteristic when completely covered by ,A tiling 62. `IIowever, when desired, a por- Itacte'd only slightly by the gases.

tion of the tiling 62 may be removed to eX- pose the upper surface of the elements 30', the tiling being formed in two parts 64 and 66 so that upper parts may be removed for this purpose. Uncovering elements 30 by removal of some of the-tile parts 66, however, doesv not greatly alterjtthelradiant type heating characteristics of elements 30 sincethese elements lie so close against the upper' surface of the'. arch thatltheyare'f'coii The upper and rearmost arch brick 34 in Figs. 4-and 5 are of slightly different shape from the brick 34 topermit the tile parts 66 to be placed over the free ends of units 30. Similarly, the forward and lower jbrick26a-1of the arch shown inv Figs. 4 and 5 is specially shaped to hold the tiling 62 in placef What I claim is: 'Y l. The combinationY in having arch tubes, of baffling on said tubes adapted to radiateheat from itsupper sur. face and extending downwardlyV at therear of the lowerl ends of said-tubes, headers near the lower ends of'said tubes, and-supera tonelli fire-L52' heater elements 'arranged along theup.p er

and forward surfaceof said' baffling and having end portions runningdown vtofandconnected with saidhe2-1ders,4 said members4 all so arranged that said, end-',portionsflie outside the current of combination .gas' es v V-2. Thecombination asset .forthin' l together with removable 4tiling over parts of the superheater elements.i

8.. The combinationpm .a boiler fire-'bok having arch tubes, of baiiiing means on said tubes, headers nearthelowerhends of said tubes and two sets-of. superheater units. having connections 4.with said,zheaders,l the units of one of said sets arranged forward of said'headers and the unitsbfjthe .other of said sets arranged yabove saidbathing means.A I I 4'. The'combinationas set forth in .cla-im l and inwhich the heat absorbing .portions of the superheater elements lie-in parallel planes. y

' 5. f The combination asset Vforth in claim-1 and in which the -superheater elements arel bent so that` the heat absorbing portions lie" in thesameplane. c v

6. The combination as set :forth in claim l and in which thes'uperheater 'elements are bent so that their heat absorbing por tions lie a planesubstantially parallelto the baffling on the arch tubes. `z

7. 'The combination as set forthin claim 1 .togeth'er with fire wall in the forward portion of the lireboxextendingnp .tothe level of the archtubesatthefforward end,l

mouse low the level of the upper rear end of the baie.

9. The combination in a boiler fire boX having arch tubes, of baiiing on said tubes, superheater elements arranged along the upper surface of said bathing, and headers for said elements near the lower ends of said tubes to which the elements are connected, said baiing having non-metallic means separate from said elements and arranged to protect the rear upper ends of said elements from direct impact of gases.V

10. The combination in a boiler fire box having arch tubes, of baffling on said tubes adapted to radiate heat from its upper surface, super-heater elements arranged along the upper surface of said baiing, headers for said elements near the lower ends of said tubes and to which the elements are connected, said baiing having refractory means at its rear upper end adapted to protect the rear ends of said elements from direct impact of gases and having means at its lower end adapted to support the longitudinal thrust of tiling carried on its upper surface.

HENRY B. OATLEY.

CERTIFICATE 0F CORRECTION.

Patent No. 1,905,739. April 25, 1933.

HENRY B. OATLEY.

1t is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 96, claim 1, for "combination" read combustion; and that the said Letters Patent should be read with this correction therein that the same may confbiltb lilzfecord of the case in the Patent Office.

` Signed andrsealed this 8th day ,of January, A, D.v 1935;

(Seal) Acting Commissioner oi Patents.

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