US2599316A - Steam generator - Google Patents

Description

June 3, 1952 R. J. BOYER 2,599,316

' STEAM GENERATOR Filed Aug. 8, 1947 3 Sheets-Sheet l INVENTOR Fig 1 I fiaymond Jfioyer ATTORNEY June 3, 1952 BOYER 2,599,316

STEAM GENERATOR Filed Aug. 8, 1947 5 Sheets-Sheet 2 0000000000 0000 ooocoocooononoo INVENTOR fia'g zona J Boyer i ATTORNEY R. J. BOYER STEAM GENERATOR June 3; 1952 5 Sheets-Sheet 3 7 Filed Aug. 8, 1947 INVENTOR ayzzzond TTORNE the :inlet of the gas pass. heater tubes form extensions of the tubular-parts Patented June 3, 1952 STEAM GENERATOR estfield, .N. J., assignor to :Raymond J. .Boyer, M7

The Babcock -& 'Wilcox Company,

New .York,

.N. Y., acorporation of NewJersey 'ApplicationiAugust 8, 1947,.Serialflo."7.6!1;581

' :8 Claims. (01. 122-478) .1 This invention :relates ":to .:steam .generators. The invention isa water tube. steamgenerator including a vertically elongated :furnace, :the walls of which are definedby steam generating tubeswhich provide :the major part of the steam generated by the installation. The :furnace gases :flow laterally "from the furnace across horizontally spaced upright steam generating tubes and then .to an "upright'gasgpass in which part of .a high temperature :superheater is .dis- :posed. The :remainder -.of thesuperheater consists of upright tubular sections constituting a bank of tubes disposed between the furnace and The upright-superof .the superheaterin the :gas- .pass: so .that :steam flows transversely ofzthe :flow :o'figases in thegas pass, then through therupright :tubular sections between the gas 'pass and the f urnace,- -and then through other parts .of the superheater tubes to a sup'erheater outlet "on the opposite :side ofthe gas .pass from the iurnace.

The invention provides :steam .at a;high;superheat with minimum requirements :for high :cost alloys for parts of :a .isuperheater disposed in a high temperature 'gas zone. It also provides .a

steam 'generating installationin which the superheater tubes are accessible through an external outlet header which, by :reason .of the type of superheater construction can be 1 disposed :at :such a position that troublesome .and :complicated provisions for gas .sealing the :wall construction 'around the superheater :tubes :adjacent the header are unnecessary. i-Byi-virtue :of the particular construction of the superheater utilizing continuous tubes which provide a horizontal "bank of tubes inan upright gas passgand 'a-sub- 'stan'tially: spaced upright .bank oftubesrat al'high temperature gas zone, the superheater outlet header is also so 'disposedthatithe tubular steam conducting elements extending therefrom can be constructed and arranged atiminimumncost and with a minimum interference with the associated .rparts of the installation.

The: invention as specified-.aboveis particularly advantageous when the super-heater is divided into high temperature and low a'temperature secti'ons having tubes constructed in the manner tween -the two superheater sections. :In this event, a plurality of superheater headers are needed, together with a number of high pressure ,Jsteam con'duits for conducting "steam from one section' to-the *attemperator, back from the attemperator 1 to the other. superheater .section, and then .irom the other superheatersection to a point-0f use.

The super-heater of the invention .is .of such construction that water, :used .to protect the superheater tubes in starting up,-can .be-readily discharged from the tubes when-steamis about to pass through the tubes under :operativeconditions. Under .-a banked :condition, .the.-superheater tubes can be maintained undenegualized temperature {conditions inasmuch .as the construction inherently tends "to :avoid a condition wherein one part of the .superheater contains Water and another part vcontainssteam or water vapor. The superheater also facilitates the .removal of scale accumulations in the superheater tubes by washing or chemical cleaning.

The invention "will be-zdescribed :withwreterence to the accompanying "drawings :which show a preferred embodiment .-of the invention, and

other objects of the invention-will appeamasrthe accompanying description proceeds.

In :the drawings:

Fig. 1 :is "a vertical ,section through the aillustrative steam generator;

Fig/f2 'isia partial vertical section .on the :line 2-2 of Fig. :1, illustrating the arrangement-10f superheater and economizer :tubes;

Fig. .3 is a horizontal section-on the qline 3- 3 of Fig. 1.; and

Fig. 4; is. a partial horizontal :section on the :line 4- 4 ofFig- 1.

The steam generator shown in the drawings includes a primary cycloneiurnace lfliromwhich burning fuel and combustion :products rpass through the intermediate furnace =:chamb:er .12 to the-secondary combustion chamber 14. This furnace construction and arrangement is :particularly adapted for burning crushed coal under high temperature 7 conditions, the slag being idischarged from the "hearth 15 through the slag tap opening ll.

The 'furnace and combustion chamber walls are defined by rows of steam generating tubes connected to discharge steam and waterinto the steam and water drum 22, some of the tubes being connected into the boiler circulation system by appropriate conduits between lower headers such as 28-29, and'the large diameter upright downcomer 3| disposed at the side of the installation and'connected't'o the water'space of the drum 22.

The high temperature section of the furnace, including the oycl'one furnace ;l 0 and *the intermediate '"furnace chamber I 2, has the iurnaoe At the upper part of the secondary combustion chamber l4, as illustrated in Fig. 1, the, gases turn to the right and pass across a bank of upright steam generating tubes 38. As shown, these tubes directly connect the drums 20 and 22.

Beyond the bank of steam generating tubes 38, the gases flow over the superheater sections and then downwardly through the gas pass 32 over the tubes of the economizer 34. Beyond the economizer, the gases pass through the tubes of the primary air heater section 34 and then continue over the tubes of the low temperature economizer section 35. While passing over this economizer section, the gases turn and then pass upwardly through the tubes of the secondary air heater section 38, andthen through the duct 48 which leads to the tubes of a third air heater section 42. From the gas exit side of this air heater section, the gases pass to the flue 44. Ap-

propriate gas pass walls combine with the furnace and the combustion chamber walls to provide for such movement of the gases.

From the steam and water drum 22 tubes 58 lead to a primary inlet header 52 of the superheater.

tubes are aligned to define the roof 54 over the Intermediate sections of some of these gas pass '32 and beyond this roof, upright sections of the tubes 50 define the wall 56.

From the super heater inlet header 52 the steam passes through rows of multiple-loop superheater tubes forming the bank of tubes 58. From this bank, the tubes continue through the vertical tube bafiie B8 and then have looped sections 62 and 64 extending'upwardly at a position rearwardly of the bank of the. tubes 38, rela- 'tive to gas flow. Steam flows upwardly through the sections 62 and 64, then downwardly through the connected loop sections 66 and 88, and then horizontally through the upper tubes 89 of the bank of tubes 58 to an intermediate superheater,

header 10, the sections 62, 64, 66, and 68 constituting an upright bank of superheater tubes.

From the header 18 the superheated steam passes through an external conduit 12 to'an attemperator 14 within the drum 2B.

16 to the inlet header [8 for the second superheater section 80. This section, as shown in the drawings includes a bank of multiple loop tubes -with their successive tubular elements extending horizontally back and forth across the downward gas flow within the gas pass 32;

, I The tubular elements of the superheater section 88 'are extended between the tubes of the bafiie 69 so that the steam then flows through the upwardly extending loop sections -82 and 84, then through the connected downwardly extended loop sections 86 and 88, and then through the top I tubes of the horizontal bank of superheater tubes 80. to the outlet header 90 of the superheater. From this header the steam flows toa point of use.

-.O.the total surface of the primary superheater section less than half is formed by the tube .-sections, 62, 64, 86,-and 68 which extend vertically From this T attemperator the steam flows through a conduit across the horizontal flow of furnace gases. These vertically extending tube sections are more widely spaced and are made of a steel of higher heat resistance than the steel involved in the horizontally disposed tubes of section 58. Similar arrangements and considerations apply to the bank of tubes 80 and the comparison of their surface to that of the tube sections 82, 84, 86 and 88.

Because of the fact that only a smaller proportion of the total superheater surface (the upright superheater tubes) is exposed to higher temperature gases, the additional expense involved for the more costly metal of these tube sections is minimized.

The illustrative steam generating installation also includes an economizer having upright wall cooling tubes 92 and 93 at the opposite sides of an upward extension of the gas pass 32 two of such extensions being separated by the rows of upright tubes 92 and 93 (see Fig. 2) which may be utilized to support the horizontally extending coils of the main economizer section 34 immediately below the superheater tubes of section 58. As illustrated in the drawings (Fig. 2), the tubes 92 have their upper ends connected to a horizontal header I00 and the tubes 93 and 94 are similarly connected to a similarly and intermediately disposed header I82. These headers and a header similar to header I89 at the opposite side of the gas pass are directly connected to the steam and water drum 22 by circulators such as I 84 and I 06.

The feed water enters th horizontal return bend tubes of the second economizer section 38 through an inlet conduit H8 and, after passing through these tubes, flows through the connecting tubes H2 to inlet headers such as the header H4, of the economizer section 34 (Fig. 1). The Water flows back and forth through the return bend tubes of the section 34, through the upright wall cooling tubes such as 92-94 (Fig. 2) to the outlet headers such as I88 and H32, and then through circulators such as I84 and I88 to the water space of the drum 22.

As illustrated, the economizer section 35 is functionally disposed between the air heater sections 34 and 38 (relative to gas flow) with the air inlet at the top of the installation as indicated at H6 in Fig. 1. From this inlet the air flows horizontally as indicated by the arrow I I8 across the upright tubes of the first air heater section 42 and then downwardly through the upright duct I28 to the spaced upright tubes of the intermediate air heater section 38. The air flows downwardly around and between these tubes and is then guided in turning to the left (Fig. 1) by the angular baffles I2 l|23. The air then turns again and flows upwardly over and between and around the spaced upright tubes of the air heater section 31 to an outlet I26 which is connected to an appropriate chamber from which the heated air is supplied to the burner of th primary furnace Ill.

The wall 69, between the bank of steam generating tubes 30 and the upright parts of the superheater, i defined by tubes I48 and I42 which directly connect the upper and lower drums, 22 and 29, respectively. The lower parts of these tubes are in single row formation along the wall or bafli I44 which extends obliquely upwardly, and past the superheater section 58. Alternate tubes, I42, are bent out of this single row arrangement above level of the horizontal superheater sections 58 and 88 toprovide for gas flow to the gaspass 32. Beyond this position the tubes I48 and-.142 sex-tend throuehethesrpef dl to;-the 22. .iQtherstuhllars tensions of tim ofstheitubesof rthegwall fifile. tenderer he superheater section 150'. and ;;then term a partof th tarchiorlroof theton-ofcaspass 3.; :t. tensions-take: the place, ofsome th tub c. ,whichact as directiverticalhan ersi r ,th aheade -52.

,nmtheupn r portion of theses pas t athe ,saturatedssteam asnpply-e ub id 3 1 13338 econoimizerioutletewalll;:tubesasucnas fizefiizan effective to absorb heat from a W. gthese stubes .-:act;-as-;;Wa11, idefinn 1 411 tubes:for.-;the;g as pasststructune.

sWhatfismlai-med is:

azatertub ,steameenera ne n l ti o. unnac suprieh st amisen ta 'ns he :some ef tvhic-hyin .vt l tube f 1 1 -meansefbr connectingsaid :steamgenerati-n tubes to the ,,-circulation systempf the ;-ins tallation, J ans mltoviding for EhBjIatBIQJJHOW Of gaSQ -tfijQm the furnace acrossisomeof the csteamsgeneratine gtubesand then to an uprightjga-s passrbeyondzath isteam generating ,tubes, ,a superheater aincluding as headerattheside ofisaidigas spass opposite the =.fnrnace,--the superheater including tubes having :series connected parts donning :,a bank .of verti- ,eally paced itubes extending .agenerally hOIiZDnltally acrossthe flow ofgases inisaid gas pass and upright parts ;forming a vbankpf horizontally gspaced-gtubes disposedbetween the gas pass and .;sa id;-furnace ;.and series connected ..with the :first parts, and means connecting tnersuperheater 5 the fluidsystemto provide for the fiow of steam to the superheater, said upright parts being directly connected only at their 'upper ends and connected for series flow to th e horizontally.. extending superheater tube parts atthe lower ends of the upright parts to render the superheater drainable by gravity.

2. In a steam generator, upright steam generating-tubes some of which define the walls of a {furnace meansfor-firing-thefurnace, asteamgand -vv{ater drumito which the tops of the steam generatingtubesare connected, a first superheatensec- --tion includi-ng vertically extending tubesgdisppsed a high temperature gas zone, second superheater section including spacedhorizontally extending tubes extending ac'ross' the downward flow of gases in a gas pass-beyond the furnace wall Eitubes exposed A to the heat. of .the furnace gases in the gas turning space at the top of said gas pass and conducting steam from th steam and Water drum to the second superheater section, the tubes of the second superheater section being connected to the first superheater section for steam fiow from the second section through the first, a bank of horizontal economizer tubes disposed below the tubes of the second superheater section and extending at 90 thereto, and additional means providing heat absorbing walls of the gas turning space, said additional means including rows of upright economizer outlet tubes extending upwardly past the second superheater section and acting as supports for the bank of economizer tubes.

3. In a steam generator-superheater installation, steam generating tubes some of which are wall tubes defining the boundaries of a furnace, a steam and water drum communicating with the outlet ends of the steam generating tubes, means for firing the furnace, means providing a fur-' nace outlet zone of horizontal providi g an upright gas pass of horizontal gas flow, a primary superheater gas flow, means beyond said zone s ction inc udin a plurality iqf ,n ultiple-= loep teturninendatu es 11y ithe floyv of gases hea e section ec esupe heate se --ml ltin1 loo t be zhQriz'ontal-ga flo n-sup pos d in, a row .elon

#19 5 wh r :t e ea e urnrfmmihmti through said furnace outlet zone 6.0 riz nta c tenq h l ti n r lsu than,wetness- DQS. extendin up a. id a ls l i r toflithe n imamsuperhea e 'se t on;

miner= cutletatubesziormins gas coolne walla? gas-turnina nac a dsupmttsriontha eener. .:I-n .a steamrsene at zsupe heate ainsta lat emrsteamgeneratin tubessome o l-whi he wall @tubes zdefinin it e boundari le ia inmate :1 asteam cand watersdrum communicating with the J outlet ends ofhe, steam generating ztubes means :fcr firing the-furnace, means l-providine a; furna e outlet zone. of horizontal-gas ffiQW ineans-mgovim vring an uprigh eas pass beyond a aid en o horizontal igas --;flow, .-.a v primary supBrheaten-sa- 11101). sincluding a plurality of ,serially connected and -.spaeed tubes i. extending horizontally across the flowrofigasesein saidegas pass; andconnected Vito: vertically extending tubes ,disposed-iwithinthe ozone. ofhorizontalgasflow, a. secondesuperheatgr sectionreceivingesteam 1from;-the,-primar-y;super heater section and includingi a;plura1ity;025811193 ,connecte'd tubeisections, verticallyglispesedacross ithe-ihorizontal ,agas flow, superheater inlet tubes disposed in arow alongiaiwall effthenup ii ht gas pass where the gases turn :from nprizontal :flow :to .adownward sflow, -,a :bank of shorizontally exitendingeconomizergtubesdisposed below-ithe; tubes of the -primary superheater section, theieconomiz'er Jtubes extending -at might .angles :to the hotizontal-tubesof the primary superheater, and economizer outlet :tubes extending; upwardly iin lwall formation onopposite sides of the npright egas pass and on opposite asides of 5 the bankeof I the horizontal. tubes. of the pri-marylsuperheater section, said economizer outlet tubes forming supports for the economizer and defining walls for said gas turning space disposed at to the row of superheater inlet tubes.

5. In a steam generator, a steam and water drum, steam generating Wall tubes defining boundaries of a furnace and having their upper ends connected to the steam and water drum, 2 high temperature superheater section consisting of serially connected and vertically extending tubular sections exposed to the heat of the furnace gases in the high temperature zone of the gas outlet of the furnace, means providing for a downwardly extending gas pass leading from the furnace gas outlet, there being a space at the top of the gas pass for turning of the gases, a second superheater section consisting of horizontally extending serially connected tubes disposed across the gas flow in said downwardly extending gas pass, the tubes of the second superheater section being connected to the tubes of the first for series flow of steam through the tubes of the second and then through the tubes of the first superheater section, means for conducting steam from the steam and water drum to the tubes of the low temperature superheater section, said last named means including wall tubes along a wall of said gas turning space, an economizer including a bank of horizontal tubes disposed below the tubes of the second superheater section and extending at 90 thereto, and economizer outlet tubes extending in wall formation upwardly past the second superheater sections and said gas turning space.

6. In a vapor generating and superheating unit, a furnace having walls including upright vapor generating tubes, means firing the furnace, wall means providing a gas pass disposed laterally of the furnace, the gas pass being constructed and arranged to receive the gas from the furnace for vertical flow of the gases therethrough, other wall means providing for substantially horizontal flow of gases from the furnace to the gas inlet of the gas pass, a first superheater section including horizontally spaced and series connected: lengths of superheater tubes disposed vertically across the horizontal flow of gases from the furnace to the gas pass, a second superheater section including vertically spaced lengths of superheater tubes disposed horizontally across the vertical fiow of gases in the gas pass, the superheater tube lengths across the horizontal gas flow being directly connected to some of the superheater tube lengths in the gas pass so that there is series flow of vapor from one superheater section to the other, the tubular elements of the superheater sections and the gas flow wall means being so arranged that at least the major portion of the gases of the horizontal gas flow and at least the major portion of the gases of the vertical gas flow flow across the associated superheated tube lengths.

7. In a vapor generating and superheating unit, a furnace having walls including upright vapor generating tubes, means firing the furnace, wall means providing a gas pass disposed laterally of the furnace, the gas pass being constructed and arranged to receive the gas from the furnace for vertical flow of the gases therethrough, other wall means providing for substantially horizontal flow of gases from the furnace to the gas inlet of the gas pass, a first superheater section including horizontally spaced and series connected lengths of superheater tubes disposed vertically across the horizontal flow of gases from the furnace to the gas pass, a second superheater section including vertically spaced lengths of superheater tubes disposed horizontally across the vertical flow of gases in the gas pass, the superheater tube lengths across the horizontal gas flow being directly connected to some of the superheater tube lengths in the gas pass so that there is series flow of vapor from one superheater section to the other, the tubular elements of the superheater sections being distributed entirely across the horizontal flow and the vertical gas flow in the gas pass.

8. In a vapor generator, a furnace including vapor generating wall tubes, a vapor superheater including banks of unitary tube sections 'each having two directly united legs angularly and transversely related to each other, means constituting a gas pass having directly joined and transversely related legs, the angle of the transversely related legs of each tube section being oppositely opening relative tothe angle of the transversely related gas pass legs, parallel and corresponding superheater tube legs extending transversely of substantially horizontal gas flow in one gas pass leg and the remaining superheater tube legs extending transversely of upright gas flow in the other gas pass leg, and a superheater header connected to the lowermost part of the unitary sections whereby the superheater is drainable by gravity, adjacent superheater tube legs remote from the header having direct connections only at their ends most remote from the header.

RAYMOND J. BOYER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,207,247 Frisch July 9, 1940 2,287,129 Pyle June 23, 1942 2,293,040 Bailey Aug. 18, 1942 2,330,240 Raynor Sept. 28, 1943 2,354,059 Rehm July 18, 1944 FOREIGN PATENTS Number Country Date 367,276 Great Britain Feb. 18, 1932

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