US2371226A - Steam generator - Google Patents

Description

- March 13, 1945. G. H. DANIELS 2,371,226

STEAM GENERATOR Filed Oct. 24, 1941 4 Sheets-Sheet 1 -l z H INVENTOR.

I GeorgeHDaniels Attorney March 13, 1945. DANlELs 2,371,226

STEAM GENERATOR Filed Oct. 24, 1941 4 Sheets-Sheet 2 Fig.2

OOOOOO INVENTOK George H Danie/s March 13, 1945. G. H. DANIELS 2,371,226

STEAM GENERATOR Filed Oct. 24, 194-1 4 Sheets-Sheet 3 Fi .5 v

INVENTOR.

Georg H. Daniels Attorney March 13, 1945.. G. a. DANIELS 2,371,226

STEAM GENERATOR Filed Oct. 24, 1941 4 Sheets-Sheet 4 INVENTOR George Danie/s BY Patented Mar. 13, 1945 UNITED" STATES PATENT OFFICE.

STEAM GENERATOR George H. Daniels, Westfield, N. J., assignor to The Babcock & Wilcox Company, Newark, N. J a corporation of New Jersey Application October 24, 1941, Serial No. 416,391

2 Claims. (01. 122- 418) The present invention relates in general to the construction and operation'of vapor generating units, and more particularly, to water tube steam generating units especially adapted for use in the marine field and of the type in which a steam superheater is in position to receive heating gases from an independently fired auxiliary furnace chamber incorporated in thegenerator setting and operable to control the steam superheat temperature, whereby the unit can be p erated to deliver saturated or superheated steam.

The main object of my invention is the provision of a steam generating unit of the general type described which is characterized by its simplicity and low cost of construction and instal lation, low space and headroom requirements,

efficient combustion conditions in the main and auxiliary furnace chambers, adequate protection of the superheater during periods of saturated steam production and at starting-up, control standing of the invention, its operating advantages and specific objects attained by its use;

reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described several embodiments of my invention.

Of the drawings: a

Fig. 1 is a sectional elevation of a sectional header steam boiler constructed in accordance with my invention;

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1;

Fig. 3 is a sectional elevation of a modified sectional header steam boiler; and V Fig. 4 is a horizontal section taken on the line 44 of Fig. 3.

In the steam boiler illustrated in Figs. 1 and 2, an insulated casing or setting It! surrounds the boiler pressure parts, which comprise a horizontally inclined bank of straight steam generating tubes 35 extending between vertically arranged longitudinally spaced roups of uptake headers 36 and downtake headers 31, the upper ends of these headers being connectedto the steam and water spaces respectively of a transverse steam and water drum 38'adjacent to and above one end of the tube bank. The tube bank 35 extends across the upper part of the setting and the setting space therebelow is occupied by the furnace portion of the unit. The lowermost tube rows of the bank are spaced from the remaining rows to provide an interdeck space 39 for a steam superheater, consisting of nested rows of horizontally extending U-shaped tubes 48 supported atspaced points on water utbes extending between the header groups and'with the opposite ends of the superheater tubes opening into superjacent external headers 4| and 42 arranged for a two-pass steam flow. The steam drum 38 has a valved outlet Hi, to which is connected a saturated steam branch line I! and a superheater supply branch pipe I8. The rows of generating tubes 35 below the superheater form a water tube screen between the superheater'and the subjacent furnace section. The superheater is arranged in the portion of the tube bank space adjacent the downtake headers 31, the superheater tubes extending transversely across substantially the full width of the bank and being removable through one of the side walls of the unit.

The lower part of the setting is divided into separate laterally adjoining furnace sections 20 and 2| by a vertically extending fluid cooled wall or partition 22, formed by a row of water tubes 44 with refractory material closin the inter-tube spaces. The partition extends upwardly to the lowermost row of the main bank 35, where the tubes 44 are bent laterally to connect to the up- I take headers 36.

The lower ends of the tubes 44 are connected to a transverse header 41. Opposite walls and the floors of the furnace sec- "tions 28 and 2| are fluid cooled by rows of tubes 48 and 49, respectively, the tubes 48 being connected to the downtake headers 31 and serving as water supply tubes for the header 41, while the tubes 49 serve as generating tubes. The tube rows 48 and 49 may be wholly or partly covered with refractory depending upon the furnace temperature conditions desired to be maintained. External downcomer tubes '50 also supply the header 4! from the steam and water drum 38. This additional generating surface in the path of theheating gases from the furnace '20 aids in maintaining a uniform temperature at the gasoutlet when both furnaces are in operation. r

With the described construction the furnace section 20 will serve as the main or saturated furnace, and the furnace section 2| as the auxliary or superheater furnace. Each furnace is provided with one or more liquid'fuel burners 38 in one of its side walls, the saturated furnace burners being preferably controlled in response to steam pressure, and the superheater furnace burners in response to superheater outlet temperature. The furnace wall opposite the burner wall is preferably fluid cooled by a row of horizontally inclined water tubes lining that wall and extending between vertical headers 52 and 53, the header 52 being directly connected to the water space f the dnum 38 by downcomen-tubcs 54, while the header 53 is directly "connected-to the steam space of that drum by riser tubes 55 which extend across the gas outlet of the unit. In the construction shown in Figs. l'and ZLthe superheater furnace section 2| is located directly below the superheater tubes 40. "The saturated furnace is thus locatedbelow the-uptakeend of the tube bank 35, so that when the saturated furnace alone is in operationzztheilleating gases therefrom will advantageously flow across only the uptake ends of the tubes 44. and "35. -ihmestallic baffieafife extends upwardlyefrom, the upp r g'i1 d f-w the, partition 22 along, the inner. endof -.th e superheater, terminating at the ,upper level -;of the superheater, 11,30 protect ,the-. superheater tubes, from, c0ntact-,-withgand; radiation; from ,the he tin e s f mthewaturated.v furna W i at-.the same timesallowitgg these,- gases, to contact with aa substantial-length "of, the .superj acent generating tubes35. r At,- starting' 1 1p: or whcn s x as desired, the; saturated iumace burners .alone are ,used, ,the ,heatin ases generated flowing .acr;OsL the npper, portion-. of the generatin tube thank, int-a,- single nasshfiow. When ,superheated steam-v is-sdesired the superheaterr iurnacabumerstares operated-:alone ;-or inconjunction with the. saturated furnace burners, .the heating, gases generated flowing:- successively ,acrossrtherscreen ,tubes 35?", the superheatertubesv 40,;andthere. .gmaining ,,tub.e rows :of ,the -,,-'8enerating ,bank. When, ieithenset, of burners. isroperatedtalonethe heating: gases: tend :to, flow, over a ,maJ' or, portion of the length of the generating tubes above the ,superheater. When ,both sets: of, burners .areoprprated, the heatin s streams from .1 the -.two rfurnaces, join in the; uppetrparteof thev unit and .ilow to {a common: as :outlet. flue fills-in -.-Which ,torr .bOilen-econ my. a tubularsair heater 6| iszlo- .pated.

- Thecdescribedi construction :due-to the. relative arran ement-rand construction of)- the main generatingubankrand furnacesections, provides a unit ,cf simplegdesignsand, relatively, lowtcostof ,constructiOn and installation. Its inherent r-low .space, requirements. .operation.,.of 'all -,the :;-burners from: the same operating; level,,.-single gas, outlet initheaupper partiof the aunit and easeof-replacement 10f the generating and ,-.superheating tubes :renders {the '.unit =e$pecia11y adapted for marine service. ,Thedescribed superheater-loecation Within the lower part (of the ,tube thank .and close tovtheafurnacem permits: high-superheat temperaturetor-besattainedean acorre- -snon ins 1y wide range tot :superheat temperat re control as iwelliassailowpentercof gravity 4 for ,the unit and, simplification.pftheisuperheater header support 'Jllhezsin le pass..iiow :of heatin rgases over the =main ,-generating bank and the substantial absence of baffles in tthatibank insures a low hr-aft aloss -.,through the unit 'and ;an .eff,ective, utilization of the heating;gases i rel vative r the ;availeble rflu-id heating -,surface.

.Inthe ,med-ifiedt.censtructicnsshown in. Figs. 3 and A, however, ,the riumace ,sections '20 :and "2 I .,are,reversedrasitoylocation and the superheater aturated steam. only 40 positioned in the uptake section of the interdeck space 39. In many installations the number of liquid fuel burners required in the superheater furnace will be greater than necessary in the saturated furnace. The relative arrangement of the superheater and furnace sections shown in Figs. 3 and 4 satisfiescombustion space requirements under such conditions, while at the ersame'time lowers the: headroom requirements of 10 the; unit. The "operating advantages set forth in connection'with the construction shown in -"Figs.1 and 2, are also present in the modified construction shown in Figs. 3 and 4. While in accordance with the provisions of the :,15 :Sta,l uteS1II- have-illustrated and described herein .the bestforms of the invention now known to me, "those skilled in'the art will understand that changesmayrbemade in the form of the apparatus disclosed without departing from the spirit 2o -of'-the invention covered by my claims, and that certainfeaturesof the invention may sometimes be used. to .advantagefwithout a corresponding use 20f other features. T'In the claims, water is used generically. to, also include other vaporizable 'jliquidsof diifei'ent'.,boiling,points, such as diiphenyland 'djphenyl oxide, and steam to ge- ..ner,icallyi'include'the vapor pro'duced'from such tiallliq id.

I claim:

flfiAvsteamgenerator comprising a setting, a bank .of horizontallyl inclined steam generating 'tubesextending vacross said setting, a furnace chamber;arranged' below-one end portion of said tube :bank, .aisecondxfurnace chamber arranged .below' the, oppositeend portion. of said tube bank,

means ,for independently Jfiring said furnace .chambers,.,a group ,of ,steamesuperheater tubes ,positioned vwithin said .tubeibank and confined to the v,portion thereof it above said .first furnace =40 .c.hamber,.,generating. tubes .in, said tube bank arran ed to ,supportsaidsuperheater tubes, the rmajor portionof the. tubes, of,said tube bank being arranged to extend acrosssaidtsetting above said superheater tubes a transverse steam and water ,drumconnected tossaidv steam generating tubes and. having asaturated steam connection to said superheater.- tubes; a second saturated steam out- .,.letfl:connection:from saiddrum, .a single heating egas routletiflue, in the-top of said setting armangedtomeceive all of the-heating gases from both of isaidrfurnace chambers, said outlet flue heing soslocated .that the heating gases from said first furnace chamber flow upwardly across said superheater tubes and substantially all of tthes-steamcgenerating tubes -of-said bank in a single, passflow .before'entering1said flue and the heating gases from said second-furnace cham- Hber-flow upwardly-across only the steam generating tubes of said bank before entering said dine, and a-vertically-extending partition separating said furnace chambers and terminating adjacent the upper level ,of. said superheatergand arranged to shield said superheatertubes from :radiationfrom saidsecond. furnace chamber.

2. A steam generator comprising ;a;setting, a .bank of horizontally inclined 1 steam -generating .tubes (extending :across said vsetting, a furnace ,chamber arranged below the .upper end portion refs-said tube bank, iatsecondfurnace chamber ar-ranged sbelow-the lower :end portion ,of said ..tube bank, 'meanszforlindependently firing said .furnaee'chambers, a, group of steam superheater tubespositicned within-said tube bank and con- ;fined to the uper endportion thereofabovesaid 7 ,first ifurnace chamber, generating tubes in :said

2,371,226 tube bank arranged to support said superheater tubes, the major portion of the tubes of said tube bank being arranged to extend across said set ting above said superheater tubes, a transverse steam and water drum connected to said steam bers, said outlet flue being so located that the V heating gases from said first furnace chamber flow upwardly across said superheater tubes and substantially all of the steam generating tubes of said bank in a single'pass flow before entering said flue and the heating gases from said second furnace chamber flow upwardly across a only steam generating tubes before entering said flue, and a vertically extending partition separating said furnace chambers and terminating adjacent the upper level of said superheater and arranged to shield. said superheater tubes from radiation from said second furnace chamber.

GEORGE H. DANIELS.

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