US2092299A - Steam boiler - Google Patents

Description

Sept. 7, 1937.

J. E. BLACK ET Al. 2,092,299

STEAM BOILER Original Filed Dec. 8, 1932 INVENTO s Po crz KBeb-r' (,fiar/es S. 5 mil 1 0k E. Black, D'd

GEI TIPUDE M BLfiC/f,

- EXECUTE/X t Stea en eri g he eheater will a so Va y due define opposite sides of the heating gas pass 52. to variations in the Pressure d p ou t The gas pass is provided at its upper rear side sirable that the final reheat temperature of the b nd tubes supported by the uptake and down- 45 el'ence Should be had to the accompanying dr wdrum [l4 through tubes 21 connected to the su- 45 .Patcnted Sept. 7, 1937 amazes s'rs BOILER Application December 8, 1932, Serial No. 646,256

Renewed June 18, 1935 20 Claims. (Cl. l22-299)' The present invention relates in general to the The steam boiler illustrated in the drawing construction and operation of water tube steam comprises a combustion chamber 40 formed by boilers incorporating auxiliary fluid heating surfluid cooled walls ll and above which is arranged face in a space above a main bank of steam gena vertical heating gas pass 62. A bank of steam 5 crating tubes and below the gas outlet from the generating tubes l3 extends across the lowerg5 boiler, most portion of the gas pass l2. The tubes l3 More specifically the present invention relates are connected to a horizontal steam and water to the construction and operation of high presdrum M arranged transversely of the boiler at sure steam boilers incorporating a convection an elevation considerably above the uppermost 1O heated steam superheatcr and a reheater for point of steam generation in the tube bank'by w supeiheating steam between stages of an assovertically arranged downtake circulators l5 and ciated multi-stage prime mover, such as asteam uptake circulators it connected respectively to turbine. In steam boilers of the character dcthe downtake headers lb and uptake headers ll. scribed, the temperature to which the steam is The tubes 53 form a natural circulation steam 15 reheated will ordinarily vary directly with the generating bankthrough which a rapid circu- 15 rating at which the boiler is operated, due to the lation of the fluid is effected under the high varying m u of h at n gases to W ich'the head due to the location of the drum it. The reheater is subjected. The temperature of the vertical portions of the circulators l5- and to first stage of the turbine. Eflicient turbine op-' it a gas' tl t to,

eration demands substantially constant steam I the upper portion of the gas pass l2, but temperature conditions at the Stage of return of below the gasoutlet 119, is arranged an econothe reheated Steam. It is therefore highlymizer Eh, consistingof superposed banks of return steam be kept-substantially constant with verytake simulators and detachably connected by mg 8 IOadS- return bends located externally oi the gas pass The e et j c of 0111 invention is the p fora series how of fluid therebctween. The supvision of a steam'boiler of the general character porting provisions f theeconomizer consist of described with an improved construction and arlugs an carried by th irculators and slidably w rangement of the auxiliary fluid heating surface engaging lugs 22 mounted on return bend thereint l tions of the economizer tubes. Feed water is A or sp cifi ct of r invention is the delivered to the economizer inlet header to, and improved construction of a high pressure water flows'downwardiy through t economizer tube steam boiler 0f the high drum type incortions to the economizer outlet header M which 3 Porating both a Steam superheatel' a Steam is connected to the steam and water drum M by reheater and provisions for controlling the final tubes 25 In th space between the tube bank reheat temperature i3 and the lowermost economizer section is ar- The various features f novelty which eherecranged a supcrheater 25 consisting of a plurality 40 terizc our invention are pointed out with particuof rows of et rn bend tubes extending horizony the c s n e d t and forming tally across the gas pass I2 and supported from pa of t specifi o a better underthe uptake and downtake circulators in a man- St nd f t e e t its Operating advanner similar to the economizer sections. The suteses and specific objects attained by its use, perheater receives a supply of steam from" the ing and descriptive matter in which we have illusperheater inlet header 2a, h superheated tmted a described preferred embodiment of steam passes out through the superheater outlet 0111' invention V header 29 to an associated steam turbine.

of the .dmwmg: Q The portionof the heating gas pass 12 above a somewhat qm sectmpal Y the superheatcris divided into side-by-side chan- 5o elevation of a supcrheater boiler incorporating nels 2a and an by a vertical battle 3 extending g gz on the of Fig upwardly to a level above theibottom of the gas and outlet l9 and then horizontally intothe outlet Fig. 3 is a sectional elevation of a tube suppassage divi n hela er into horizontal chanporting conhection. nels I9 and I9. Dampers 3| and 3| are arranged in the rear portions of the channels l9 and l9 respectively, and can be manipulated to control the relative amounts of heating gases flowing through the main gas pass channels I2 and H2. The described location for the control dampers does not require the use of special designs or materials which would otherwise be necessary in case the control dampers were located in a higher temperature zone.

The bafile30 is advantageously. supported at its lower end by a row of U-shaped steam generating tubes 32 having their lower legs extending across the lower end of the channel [2 and upwardly along the uptake side of the baffle 30, which is secured thereto in any suitable manner. The upper legs of the tubes 32 also extend across the channel l2 below the lowermost economizer section and pass between the circulators I5 into a header 33. The tubes 32 are preferably connected into the circulating system of the boiler by downcomcrs 34 connected to a header 35 at the lower end of the tubes 32'and uptake circulators 36 connecting the header 33 to the steam space of the drum M. The load on the tubes 32 is carried by rods 31 embedded in the bafile 30 and extending downwardly from a top support 38 between the economizer tubes and connected to the upper bend of the tubes 32 in any suitable manner, as by welding. The use of supporting rods for this purpose does not affect the economizer tube spacing, nor will their exposed portions be subjected to unduly high gas temperatures.

In the portion of the channel I 2 between the superheater and lowermost economizer section is arranged a steam reheater 40 consisting of a double row of nested return bend tubes extending across the channcl l2 and having their ends connected to externally supported inlet and outlet headers 4| and 42' respectively. The reheater tubes, like the economizer and superheater tubes are formed in a unitary truss-like structure by plates 43 welded to vertically adjacent legs thereof. The inner end .of the reheater is supported from the rods 31 by lugs 14 on the inner looped portions of the reheater tubes engaging lugs 45 on the vertical portions of the tubes 32 in a manner similar to the arrangement of the lugs-2l and 22 previously described.

With the boiler constructed as described, feed water is supplied under pressure to the economizer 20 and delivered to the drum [4, from which it is circulated through the "steam generating elements l3 and 32 of the boiler. The steam generated passes from the drum H to the superheater, where the steam is superheated before being delivered to the point of use, such as a multi-stage steam turbine. Modern power plant practice prescribes reheating of the steam between certain turbine stages, and this is done in the present construction by passing the steam from a high pressure stage to the reheater inlet header 4|. 4

In constructions where the boiler reheater is subjected to the flow of all of the heating gases at different boiler ratings, the reheating effect will vary directly with the amount of heating gases to which it is subjected. Even with a constant reheating effect, the final temperature to which the steam is reheated will "vary with changes in the pressure of the steam at the point of return to the reheater. In the present construction, a substantially constant final reheat temperature is obtained by regulating the amount of heating gases to which the reheater is subjected by varying the relative positions of the dampers 3| and 3i to thereby regulate the proportions of the heating gases passed through the channels I2 and l2 respectively. The reheater surface is preferably proportioned to attain the desired amount of reheat at the full output rating of the boiler with both control dampers wide open. At lower ratings of the boiler the damper 3| will be moved towards its closed position to increase the proportion of heating'gases passing through the gas channel l2 as required to maintain the desired final reheat temperature. If the final reheat temperature should tend to exceed the desired value, the degree of opening of the damper 3| is decreased and that of the damper 3| increased to provide the greater proportion of the flow through the channel I2 'A substantially constant final reheat temperature can thus be maintained by proper positioning of the dampers 3i and 3|".

The described construction is particularly advantageous in that the control of the final reheat temperature has little or no effect on the heat transfer in the economizer and super-heater, as any change in the proportions of the heating gas passing through the channels l2 and' l2 will merely vary the mass fiow of the heating gases passing over the portions of the economizer and superheater surface located in said channels, but will not change the total amount of heating gases supplied to those parts.

While in accordance with the provisions of the statutes we have illustrated and described herein the best forms of our invention now known to us, those skilled in the art will understand that changesmay be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by our claims, and that certain features of our invention may sometimes be used to advantage without a corresponding use of other features.

We claim:

1. A water tube boiler comprising a combustion chamber, a bank of steam generating tubes receiving heating gases from said combustion chamber, a steam and water drum positioned above said tube bank, circulators connecting opposite ends of said tube bank to said drum and defining a vertical heatinggas pass above said tube bank, a waste gas outlet, a bafllc extending transversely of said tube bank and dividing said gas pass into a plurality of vertical channels connected to said gas outlet, a bank of auxiliary fluid heating tubes extending through said baiiie and across said channels, asecond bank of auxiliary fluid heating tubes located in only one of-said channels, and means for varying the relative amounts of heating gases flowing through said channels.

2. A water tube boiler comprising a combustion chamber, a bank of steam generating tubes receiving heating gases from said combustion chamber, a steam and water drum positioned a substantial distance above said tube bank, circulators connecting opposite ends of said tube bank to said drum and defining a vertical heating gas pass above said tube bank, a waste gas outlet ad jacent said drum, a vertical baflle dividing said gas pass into a plurality of channels from beyond said tube bank to said gas outlet, is fluid cooled support for, said bafilc, agroup of steam heating tubes located in one of said channels, means for partly supporting said steam heating tubes from said fluid cooled support, and dampers at the upper ends of said channels for vai-ying the relative amounts of'heating gases flowing through said channels,

3. A water tube boiler comprising a combustion chamber, a bank of steam generating tubes recelving heating gases from said combustion chamber, aesteam and water drum positioned a substantial distance above said tube bank, circulators connecting opposite ends of said tube bank to said drum and defining avertical heating gaspass above said tube bank, a waste gas outlet adjacent said drum, a superheater extendin acrosssaid gas pass above'said tube bank, a vertical baflle dividing said gas pass into a plurality of channels from beyond said super-heater to said gas outlet, a row of steam generating tubes extending along said baiile, and providing a fluid cooled support therefor, a steam reheater located in one of said channels, and means for varying the relative amounts of heating gases flowing through said channels. v

4. A water tube boiler comprising a combustion chamber, afibank of steam generating tubes receiving heating gases from said combustion chamber, a steam and water drum positioned a substantial distance above said tube bank, circulators connecting opposite ends of said tube'bank to said drum and defining a vertical heating gas pass above said tube bank, a waste gas outlet vadjacent said drum, a superheater extending across said gas pass above said tube bank, a vertical bafile dividing said gas pass into a plurality of channels from beyond said super-heaterto said gas-outlet, a row of steam generating tubes extending along said baiile and providing a fluid cooled support therefor, a steam reheater located inone of said: channels and including a row of return-bend tubes, means for supporting return bend portions of said return bend tubes from said row of steam generating tubes, and means for varying the relative amounts of heating gases flowing throughsaid channels.

5. A steam generator comprising a setting, a bank of inclined steam generating tubes within said setting, a steam and water drum extending transversely of and above said tube bank, circulators connecting'the opposite ends of said tube bank to said drum, a heating gas outlet at one side of said setting above one end of said tube bank,- a

row of tubes extending inwardly atthe downtake end oi said tube bank and upwardly intermediate the length of and above said tube bank and hav-" ing their upper endsfconnected to said drum, suspension means external to said drum for supporting said row of tubes, a vertically extending baifle supported on the vertically extending portion of said row of tubes and havinga lateral exte'nsion to said heating .-g'as outlet and arranged to till separate a pair of parallelflow gas passes extending above said tube bank and laterally to said heating gas outlet, a bank of fluid heating tubes extending across one of said gas passes, a second bank of fluid heating tubes in the other gas pass, and damper means in said heating gas outlet for varying the relative amounts of heating .gases flowing through said gas 'passes. l

d. d steam generator comprisinga setting, a bank of inclined steam generating tubes within said setting, a steam and waterflrum extending transversely of and abovesaid tubebank, circulators connecting the opposite ends of said tube wardly intermediate the length of and above said *tube bank, suspension means external to said drum for supporting saidrow of tubes, a vertical-f r ly extending bade supported on the vertically extendingportion of said row of tubes with its lower end terminating above said tube bank and arranged to separate a pair of parallel flow gas passes extending above said tube bank, a bank of steam heating tubes extending across one of said gas passes, a bank, of economizer tubes in ing the relative amounts ofheating gases flowing through said gas passes.

7. A steam generator comprising a setting, a

bank of inclined steam generating tubes within said setting, a steam and water drum above'said tube bank, circulators connecting the opposite ends of said tube bank to said drum, a row of tubes extending upwardly intermediate the length -of and above said tube bank, suspension means r the other gas pass, and damper means for varyof saidv fluid heating tube bank from said row of tubes and suspension means.

8. A steamgenerator comprising a setting, a bank of inclined steam generating tubes within I said setting, a steam and water drum above said tube bank, eirculators connecting the opposite ends of said tube bank to said drum, a row oi tubes extending inwardly at the downtake' end of said tubeJoank and upwardly intermediate the length of and above said tube bank and having their-upper ends connected to said drum, suspension means external to said drum for supporting said row of tubes, a vertically extending balile supported on the'vertically extending portions of said row of tubes and arranged to separate a pair of parallel flow gaslpasses above said tube'bank, a bank of fluid heating tubes extending across one of said gas passes, damper means for controlling the proportion of the heatingga'ses flowing through the other gas pass, and means for sup portingone end of said fluid heating tube bank from said row of tubes and suspensionmeans.

9. A steam generator comprising a setting,a bank of steam generatingtubs within said settin ga. steam and water drum above said tube bank, circulators connecting the opposite endsoi v said tube bank to'said drum, arow oi tubes ex tending upwardly intermediate the length of and above said tube bank, suspension means for sup porting said row of tubes, a vertically extending baffle supported on thevertically extending portionsof said row of tubes and arranged to separate a pair of parallel flow gas passes above said tube bank,a bank of fluid he ting tubes extending across one ofsaid gas passes, means for supporting one end of said' fluid heating tube bank from said row of tubes and suspension means, a second bank of fluid heating tubes in the other gas pass, and damper means for varying the relative amounts of heating gases flowing through said gas passes. I

10. A steam generator comprising a setting, a

bank of inclined steam generating tubes within" said setting, a steam and water drum extending transversely of said tube bank and directly above the downtake end thereof, circulator's connecting the opposite ends of said tube bank to said drum, a row of tubes extending inwardly at the downtake'1 endof said tube bank and upwardly intermediate the length of and above said tube bank Q and having their upperends connected to said drum, suspension means external to said drum for supporting said row of tubes, a vertically extending baiile supported on the vertically extending portionsof said row of tubes and arranged to separate a pair of parallel fiowgas passes above said tube bank, a bank of steam heating tubes extending across one of said gas passes, means for supporting one end of said steam heating tube bank from said row of tubes and suspension means, a bank of economizer tubes in the other gas pass, anddamper means in the upper ends of said gas passes for varying the relative amounts of heating gases flowing through said gas passes. X 1

11. A steam generator comprising a setting, a bank of inclined steam generating tubes within said setting, a steam and water drum extending transversely of andabove said tube bank, circulators connecting the opposite ends of said tube bank to said drum, a heating gas outlet at one side of said setting above one end of said tube bank, a row of tubes extending upwardly inter* mediate the length of and above said tube bank, suspension means external to said drum for supporting said row of tubes, a vertically extending baflie supported on the vertically extending portions of said row of tubes and arranged to separate a pair of parallel flow gas passes extending above said tube bank and laterally to said heatgroup of steam generating tubes arranged across said setting, a steam and water drum extending transversely of and above said steam generating tubes, rows of circulator tubes arranged at opposite sides of said setting and connecting the opposite ends of said steam generating tube group to said drum, a heating gas outlet in the upper part of said setting, means forming a vertical baiiie extending transversely of said steam generating tube group and dividing the space between said rows of circulator tubes into a pair of parallel gas passes having an'upflow of heating gases therein to said gas outlet, a'group of steam heating tubes positioned in only one ofsaid gas passes, 'agroup of economizer tubes positioned in the other gas pass, and damper means for varying the relative amounts of heating gases flowing through said gas passes.

13. A steamgenerator comprising a setting, a group of steam generating tubes arranged across said setting, a'steam and water drum arranged above said steam generating tubes, rows of circulator tubes vertically disposed along opposite sides of said setting and connecting the opposite ends of said steam generating tube group to said drum, means including a row of 'fluid heating tubes having portions extending vertically within said setting and arranged to form a baiiie extending transversely of said steam generating tube group and separating a pair of parallel gas passes of different cross-sectional flow areas within the space between said rows of circulator tubes and having an upflow of heating gases therein, a groupof return bend steam heating tubes extending across only the gas pass of greater flow area, means for supporting one end, of said steam heating tubes from said battle-forming tubes, and damper means for varying the amount of heating gases flowing through the gas pass of lesser flow area.

14. -A' steam generator comprising a setting, a bank of inclined steam generating tubes arranged across said setting, a steam and water drum arranged transversely of and above said steam generating tubes, rows of uptake and downtake circulator tubes vertically disposed along onposite sides of said setting and connecting the corresponding ends of said steam generating tubes to said drum, 2. row of fluid heating tubes having portions extending inwardly adjacent the downtake end of said tube bank and vertically intermediate the length of said tube bank and having their upper ends connected to said drum, a vertically extending baille supported on the vertical- 1y extending portions of 'said row of tubes and arranged to extend transversely of said tube bank and separate a pair of parallel gas passes of different cross-sectional flow areas within the space between said rows, of circulator tubes. and having an upflow of heating gases therein, the gas pass of greater flow area being arranged directly above ,the uptake end of said tube bank, a group of steam heating tubes extending across only the gas pass of greater flow area, and damper means for controlling the amount of heating gases flowing through the gas-pass of lesser flow area.

15. A steam generator comprising a setting, a

group of steam generating tubes arranged across said setting, a steam'and water drum extending transversely of and above said steam generating tubes, circulator tubes vertically disposed along opposite sides of said setting and connecting the opposite ends of said steam generating tube group to said drum, means including a row of fluid heating tubes having portions extending vertically within 'said setting and arranged to form a baffle extending transversely of said steam generating tube group and separating a pair oi! adjacent gas passes within said setting, suspension means for supporting the vertically extending portions of said bathe-forming tubes, a group of return bend fluid heating tubes extending across onlyone of said gas passes, means for supporting one end of said return bend tubes from said baffle-forming tubes and suspension means, a second group of return bend fluid heating tubes extending through said baiile and across said gas passes, damper means for varying the relative amounts of heating gases flowing through said gas passes, and means for supporting the opposite ends of said second group of return bend tubes from adjacent circulator tubes.

tubes located in both of said gas passes and above said steam heating tubes, and damper means located in the path of gas flow beyond said economizer tubes for varying the relative amounts of heating gases flowing through said gas passes.

17. A water tube boiler comprising a combustion'chamber, a bank of steam generating tubes said channels.

located above said combustion chamber, a steam and water drum positioned above said tube bank, circulators connecting opposite ends of said tube bank to said drumand defining a vertical heating gas pass above said tube bank, a waste gas outlet adjacent said drum, a bailie extending transversely of said tube bank and dividing said gas pass into a pair of channels from beyond'said tube bank to said gas outlet, a group of steam heating tubes located in one of saidchannels, a bank of auxiliary fluid heating tubes above said steam heating tubes and extending through said baflle into both of said channels, and means at the upper ends of said channels for varying the relative amounts of heating gases flowing through 18. A steam generator comprising a setting, a group of steam generating tubes arranged across said setting, a steam and water drum above said steam generating tube group, groups of circulator tubes extending along opposite sides of said setting and connecting the opposite ends of said I steam generating tube group to said drum, a vertically extending baffle arranged to divide a portion of said setting above said steam generating tube group and between said circulator tube groups into a pair of laterally adjacent vertically extending gas passes, a group of steam heating tubes extending across only one of said gas passes, a group of multi-looped return bend economizer tubes in the other gas pass, means for supporting at least one end of said group of economizer tubes from adjacent circulator tubes, and damper means for varying the relative amounts of heating gases flowing through said gas passes.

19. A steam generator comprising a setting, groups of circulator tubes extending along opposite sides of said setting, a vertically extending baffie arranged to divide a portion of said setting between said circulator tube groups into a pair of laterally adjacent vertically extending gas passes having an upflow of heating gases therein, a group of return bend steam heating tubes extending across only one of said gas passes, a group of multi-looped return bend economizer tubes in the other gas pass, means for supporting the opposite ends of said group of economizer tubes from adjacent circulator tubes, and damper means for varying the relative amounts of heating gases flowing through said gas passes.

20. A steam generator comprising a setting, a group of steam generating tubes arranged across said setting, a steam and water drum a substantial distance above said steam generating tube group, groups of circulator tubes extending along opposite sides of said setting and connecting the opposite ends of said steam generating tube.

group to said drum, a vertically extending bafile arranged to divide a portion of said setting above said steam generating tube group and between said circulator tube groups into a pair of laterally adjacent vertically extending gas passe-s having an upflow of heating gases therein, a group of return bend steam heating tubes extending across only one of said gas passes, a group, of multilooped return bend economizer tubes in the other gas pass, means for supporting the opposite ends of said group of economizer tubes from adjacent circulator tubes, and damper means in the path of gas flow beyond said economizer tubes for varying the relative amounts of heating gases flowing through said gas passes.

GERTRUDE M. BLACK,

Ewecutrix of John E. Black. CHARLES S. SMITH. ROBERT K. BEHR.

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