US2231015A - Steam generator - Google Patents

Description

c. rs. LUGKE 2,2 31,015

STEAM GENERATOR Original Filed Jan. 15, 1937 3 Sheets-Sheet 1 Feb. 11, 1941.

Fig] 5] 53 INVENT OR.

harles Zucke a W ATTORNEY.

I c. E. LUCKE 2,231,015

' STEAM GENERATOR Original Filed Jan. 15, 193'! s sn ets-sneet 2 Fig 2" f INVENTOR.

5 Sheets-Sheet 3 0000 CO 0000 0O 0O 0O 0O 00 000 |||!O 0000009 Ill. -1. qQquud 0000 on 00000000001000 oo 00 ii 1 w INVENTOR. 25/701165 rue/ 6 C; E. LUCKE STEAM GENERATOR Original Filed Jan. 13, 1937 I qmd Q o mv O 0 000000 QQOOOOQ a? A TORNEY.

Patented'Feb. 11,1941 2,231,015.

2,231,015 STEAM GENERATOR Charles E. Lucke, New York, N. Y., assignor to The Babcock & Wilcox Company, Newark, N. 3., a corporation of New Jersey Application January 13, 1937, Serial No. 120,363 Renewed June 12, 1940 10 Claims. (01. 122-336) (J The present invention relates to the construcdrum l2 outwardly at a Slight p rd inclination and operation of vapor enerati it of tion, then vertically within the setting, and then moderate capacity which are particularly charat an upward inclination to he d The acterized by their small floor space and low head P Q between the bottom l o e tubes 20 5 room requirements, and r particularly t a are {closed by metallic blocks 22 to form a floor. 5 water tube steam boiler of th t -d ty e The spaces between the vertical legs of the tubes having a single bank of generating tubes 20 are closed by refractory material to form one necting the drums and a furnace chamber latleg of an L-s p partition 24 arranged par l el erally adjoining the space occupied by the tube to ahdextending reflrwaldly beyond e par it on bank and connected thereto at only one end. Tubes in one or more transverse rows 10 The main object of my in nti i th of the tube bank beyond the end of the partition vision in a vapor generating unit of the characii are bent from t upper u wa y in ter described of vapor superheating surface, and spaced alignment across the space between the of means for regulably controlling the amo t rear end of the partition 24 and the tube bank of superheating effected over the complete range, and the intertube spaces closed by refractory to 15 A further object is the provision f an improved form the transverse leg of the partition 24. The divided furnace construction fo vapor genlower ends of the tubes 10 are connected to a erator of the character de c ib d, transverse header 25 which is connected to the The various features of novelty whi n na lower drum. A fluid cooled furnace chamber 21 acterize my inventionare pointed out with parthus formed laterally djoin the Sp 6011- 20 ticularity in the claims annexed to and forming taming the tube bank and Opening e o in a part of this specification, For a, b tt d the space between the ends of the partitions I1 standing of the invention, it operating advanand 24. The innermost tubes ll) in this portion tages and specific objects attained by its use, Of the bank are spaced to o a Sla Sc een 25 reference should be had to the accompanying oss e r ce to t e ba 25 drawings and descriptive matter in which I 0118 e fuel burners 3|] are arranged to have illustrated and described a preferred emdischarge a Strea O flu fuel. Suc a p bodiment of my invention. ized coal, oil or'gas, substantially horizontally Of the drawings: through the front wall [3 into the furnace cham- Fig. 1 is a sectional elevation taken on th her 21. With this-arrangement the'burning fuel 30 line l--I of Fig. 3; and heating gases',will travel rearwardly in the Fig. 2 is a sectional elevation taken on the furnace chamber 21. The furnace is designed to line 2-2 of Fig. 3; and effect complete combustion of the fuel therein Fig. 3 is a horizontal section taken on the line d e i g a s are directed y the trans- 3--3 of Fig. 1. verse leg of the partition 24 around the rear end 35 In the steam boiler unit illustrated in the drawof the partition 11 and forwardly in contact with in'gs.: a vertically disposed bank of steam genthe tubes of the main generating bank. The crating tubes I0 is arranged between, and conspace occupied by the main bank of tubes I0 is nected to a pair of horizontally extending upper constructe t pr v a heating g s f w r h 40' and lower drums H and I 2 respectively. The aplurality of serially connected transverse passes 40 tube bank is arranged along one side of and en across the tube bank. For this purpose a transclosed byaflat-sided setting of rectangular crossverse bafile 3| extends from the rear end of the sectional shape including a front wall I3, rear partition l1 towards the side wall l6 and a secwall It, and side Walls l5 and I6, constructed as 0nd transverse baffle 32 extends inwardly from hereinafter described. Tubes II) in the outer the side wall l6 towards the partition ll. The 45 most row of the tube bank at the side adjacent gases from the furnace ,cha'mber2l flow around the side wall l5 are spaced from the remaining the baffles 3| and 32 successively across the tube portion of the tube bank, with the intertube bank and exit through a heating gas outlet at spaces closed by refractory material or other the forward end.

suitable provisions, to form a vertically extend- Steam generating units of the general type so ing fluid cooled partition I! extending from the heretofore described have gone into extensive use front wall l3 rearwardly to a point about midway in recent years. Steam superheating surface is along the tube bank leaving a. relatively wide usually incorporated in such units in association space between its rear end and the rear wall. A with the main tube bank. Such superheaters I row of U-shaped tubes 20 extends from the lower however, have been usually arranged so that the 5' made absolutely safe superheater surface is normally contacted by substantially all of the heating gases passing through the unit and consequently thefinal superheat temperature will normally fluctuate over a relatively wide range in operation as the load changes. Furthermore, there is danger of overheating the superheater tubes when starting the unit, during the period before steam is available. to flow through the superheater tubes. A similar condition may arise after a sudden stoppage of steam flow.

In accordance with the present invention, superheating surface is incorporated in the unit in a location where it is adequately protected from excessive temperature conditions and also where, in association with an auxiliary furnace, the final superheat can be readily controlled over the entire range of operating conditions. stant final superheat temperature or different superheat temperatures desired can be effected. In addition, it is possible to generate steam without heating the superheater so that the latter is during starting or after a sudden stoppage, and during operation any fraction of the steam generated may be bled from the drum so as not to pass through the superheater without resulting in overheating the superheater tubes due to the consequent lowered steam flow therethrough.

For this purpose, the setting also includes an auxiliary furnace chamber adjoining the outer and rear sides of the furnace chamber 21. The auxiliary furnace '35 is defined by inclined tubes 36 from the drum |2 extending to a side wall header 31, and tubes 38 extending from the head-' 15 and roof to the drum tubes 36 beyond the main er along the side wall The portions of the furnace 21 have their intertube spaces closed by tube-blocks to form a floor extending rearwardly to an ash pit 39 adjacent the rear wall.

-The auxiliary furnacechamber 35 is thus of L-shaped cross-section with one end of its transverse sectionopening to the portion of the tube bank at the rear of the partition 24. A row of cooling tubes 40 protect the portionof the rear wall I4 facing the longitudinal section of the auxiliary furnace and are connected into the boiler circulation system.

One or more fluid fuel burners 4| are mounted in the front wall l3 so as to discharge a stream of fuel and air horizontally into the auxiliary furnace. The fuel burners 4| have the usual equipment. for controlling the supplies of fuel and air thereto and thereby combustion conditions in the auxiliary furnace. The auxiliary furnace is unobstructed throughout its longitudinal section, so that substantially all of the form a slag screen across the transverse section.

The tubes 43 have their upper ends connected to the upper drum and their lower ends to a header 44, which receives its fluid supply from some of the tubes 20 at the rear of the main furnace chamber. The superheating surface of the unit isformed by two spaced groups of vertically disposed return bend tubes 45 having their open ends connected to cross-headers 46, 41 and 48 at their lower ends. .The header 48 receives saturated steam from the drum through tubes 49 and the steam passes successively through the superheater groups to the outlet header 46. The

heating gases pass over the full height of the A consuperheater tubes and then across the rear portion of the tube bank II! where the gases join and mix with the heating gas stream from the main furnace. A fitting 50 is incorporated in each supply tube 49 with a pair of separate outlets respectively controlled by valves 5| and 52, so that saturated steam may be bled from the superheater supply line through pipes 53. With this arrangement all or any fraction of the saturated steam generated may be discharged through or around the superheater and the fuel burners 4| correspondingly regulated to produce the desired superheating effect on the steam to be superheated.

In operation, the unit is started with only the main furnace burners 30 in use. The heating gases generated pass rearwardly through the furnace chamber, turning at its rear end into the space occupied by the tube bank. Most of the heat absorbed by the partition tubes 10, 20

and 23 will-be by radiation from the furnace chamber. The gases then pass serially through the tube bank passes under the influence of the furnace draft. With this mode of operation, the

superheater is adequately protected during the initial period of operation, when the steam flow tures, advantageously avoiding the need of any.

control dampers for regulating the amount -of gases contacting with. the superheater surface with the corresponding problem of damper maintenance, and also of any by-passing of gases around the superheater with a corresponding loss in heat transfer efliciency. The ratio of the volumes -of the main and auxiliary furnaces and the ratio of the cold" wall area to volume of each furnace are designed in accordance with the desired normal ratio of heat of superheat to latent heat and gas exit temperature. With the divid ed furnace construction described, the horizontal legs of the tubes defining the auxiliary furnace will be adequately protected from overheating by the main furnace.

While in accordance with the provisions of the statutes 1 have illustrated and described herein the best form of my invention now known to me, those skilled in the artwill understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

I claim:

1. A steam boiler having upper and lower drums, a bank of water tubes connected to said drums along the length thereof, means forming a main furnace chamber laterally adjoining and extending along the length of the space containing said tube bank and communicating with one end thereof, means forming an auxiliary furnace at the same side of said tube space as said main furnace chamber and communicating with the same end of said tube space, a steam superheater arranged to receive heating-gases solely from said auxiliary furnace chamber, and means for burning fuel in each of said furnace chamhere and effecting a flow of heating gases substantially horizontally through said furnace chambers and thence through saidtube space towards the opposite end thereof.

2; A steam boiler having a setting including upper and lower drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, means forming a main furnace chamber laterally adjoining and extending along the length of the settingspace containing said tube bank and communicating with the rear end thereof, means forming an auxiliary furnace adjoining the outer side of said main furnace chamber andcommunicatingwith the rear end ofsaid tube bank space, asteam superheater located beyond the rear end of said main furnace chamber and receiving heating gases solely from said auxiliary furnace chamber, and separately regulable means at the front end of said main and auxiliary furnace chambers for burning fuel therein and effecting a flow of heating gases through said furnace chambers and thence through said tube space towards the front end thereof.

3. A steam boilerhaving a setting including a pair of upper and lower drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, a' partition forming the inner wall of a main furnace chamber laterally adjoining the setting space containingv said tube bank'and communicating with the rear end thereof, an L-shaped partition forming the outer and rear walls of said main furnace chamber and separating said main furnace chamber from an L-shaped auxiliary fur- 40 nace adjoining the outer and rear sides of said main furnace chamber and communicating with the rear end of said-tube bank space, walls defining the remaining sides of said'auxiliary furnace chamber, a steam superheater located in 5 the rear portion of said auxiliary furnace chamber, and separately regulable means at the front end of said main and auxiliary furnace chambers for burning fu'el therein and eifectinga flow of heating gases through said furnace chambers 50 and thence through said tube space.

4. A steam boiler having a setting including a pair of horizontally arranged upper and lower drums, a bank of vertically disposed water tubes connected to-said drums along the length there- 55 of, a fluid cooled partition forming the inner wall of a main furnace chamber laterally adjoining the setting space containing said tube bank and communicating with the rear end thereof, an L-shaped fluid cooled partition form- 0 ing the outer and rear walls of said main furnace chamber and separating said main furnace chamber from an L-shaped auxiliary furnace adjoining the outer and rear sides of said main furnace chamber and communicating with the rear end of said tube bank space, walls deflningthe remaining sides of said auxiliary furnace chamber, a steam superheater located in the rear por tion of said auxiliary furnace chamber, rows of tubes connected to said drums arranged to fluid cool said partitions, and fuel burning means at the forward end of said main and auxiliary furnace chambers.

5. A steam boilerhaving a setting including a pair of horizontally arranged upper and lower 75 drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, a fluid cooled partition forming the inner wall of a main furnace chamber laterally adjoining the setting space containing said tube bank and communicating with the rear end thereof, an L-shaped fluid cooled partition forming the outter and rear walls of said main furnace 'cham cool said partitions, separately regulable means at the front end of said main and auxiliary furnace chambers for burning a'slag-forming fuel therein and effecting a substantially horizontal flow of heating gases longitudinally through said furnace chambers and thence through said tube space, and tubes arranged to forma slag screen in the rear portion of said auxiliary furnace chamber between said fuel burning means and said superheater and in the rear portion of said main furnace chamber.

6. A steam boiler having upper and lower drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, means forming a main furnace chamber laterally adjoining the space containing said tube bank and communicating with one end thereof, means forming an L-shaped auxiliary furnace adjoining the outer and rear sides of said main furnace chamber and communicating with the same end of said tube space, a steam superheater located in said auxiliary furnace chamber, and means .for burning fuel in each of said furnace chambers and effecting a flow of heating gases through said furnace chambers and thence through said tube space.

7. A steam boiler having upper and lower drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, means forming a main furnace chamber laterally adjoining the space containing said tube bank and communicating with one end thereof,

means forming an auxiliary furnace adjoining said main furnace chamber and communicating with the same end of said tube space, a, steam superheater located in said auxiliary furnace chamber, means for burning fuel in said main furnace chamber and effecting a flow of heating gases through said furnace chamber and thence through said tube space, and means for regulably superheating a variable amount of the steam generated independently of the rate of. steam generation including a valve controlled supply line to said superheater and a saturated steam discharge line from said upper drum independent of said superheater.

8. A steam boiler having upper and lower drums, a bank of water tubes connected to said drums along the length thereof, means forming a main furnace chamber laterally adjoining and extending along the length of the space containing said tube bank and communicating therewith, means forming an auxiliary furnace at the same side of said tube bank space as said main furnace chamber and communicating with said tube bank space externally of said main furnace chamber, a convection heated steam superheater arranged to receive heating gases solely from said auxiliary furnace chamber, means for inde- .pendently burning fuel in suspension in each of said furnace chambers, and means for effecting a new of heating gases through said auxiliary furnace chamber and thence into said tube bank space at a point beyond the path of flow of the heating gases from said main furnace chamber. 9. A steam boiler having a pair of horizontally elongated upper and lower drums, a bank of Water tubes connected to said drums along the length thereof, means defining a main furnace 10. A steam boiler having a pair of horizontally elongated upper and lower drums, a bank of water tubes connected to said drums along the length thereof, means defining a main furnace laterally adjoining and extending along the length of the space containing said tube bank, means defining an auxiliary furnace extending along the length of and at the opposite side of said main furnace from said tube bank space including a group of water tubes between said main and auxiliary furnaces, means for burning fuel in said main furnace, means for independently burning fuel in said auxiliary furnace and effecting a flow of heating gases substantially horizontally through said auxiliary furnace and thence around one end of said main furnace and throughout the length of said tube bank space, and a steam superheater arranged to receive heat mainly from said auxiliary furnace.

CHARLES E. LUCKE.

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