US2159557A - Steam boiler - Google Patents

Description

May 23, 1939. L. W.-HELLER 2,159,557

' STEAM BOILER Filed Mafch 5, 1937 3 Sheets-Sheet 1 INVENT OR.

Lewis W Heller L. W. HELLER STEAM BOILER May 23, 1939.

3 Sheets-Sheet 3 Filed March 5, 1937 INVENTOR. Zewz's W/ e/kr Patented May 23, 1939 UNITED STATES PATENT OFFICE 1 STEAM BOILER Lewis W. Heller, East Orange, N. J., auignor to The Babcock & Wilcox Company, Newark,

N. J., a corporation of New Jersey Application March 5, 1937, Serial No; 129,113

13 Claims. (Cl. 122-336) having a furnace chamber with a fluid cooled ash receiving floor of substantial length.

The main object of my invention is the provision of an improved construction of a furnace of the type described, which is particularly charlO acterized by a floor construction and arrangement which contributes to the deposition of ash thereon in a dry condition, and facilitates the removal of deposited ash therefrom by cleaning fluid discharge provisions. A further and more specific object is the provision of an improved furnace floor construction for a steam boiler of the integral furnace type. A still further object is the provision of an improved construction and arrangement of a fluid cooled wing wall in a steam boiler of the integral furnace type having my improved floor construction.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding 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 a preferred embodiment of my invention.

Of the drawings:

Fig. 1 is a vertical transverse section taken on the line I-I of Fig. 3;

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

Fig. 3 is a horizontal section taken on the line 33 of Fig. 2;

Figs. 4 and 5 are enlarged views of portions of Fig. 2 showing the cleaning fluid discharge nozzles; and

Fig. 6 is a plan view of the nozzle shown in Fi 5.

My invention is particularly designed for and especially useful in steam boilers of the integral furnace type, and such a boiler is illustrated in the drawings. The steam boiler incorporates a horizontally arranged upper steam and water,

56 disposed front wall It, rear wall I4, and side walls l5 and IS. The remaining portion of the setting laterally adjoining the tube bank is occupied by a furnace constructed in accordance with my invention. I

As shown, the tube bank I! extends the full length of the setting, and is separated from the furnace chamber except at its rear end by a vertically extending partition 20 formed by a row of tubes 2| alongside the tube bank and refractory'in the intertube spaces held in position by metallic studs integrally connected to the tubes. A pair of fuel burner ports 22 are formed in the front wall l3 through which fuel burners 23 discharge streams of fluid fuel, and particularly pulverized coal, in a substantially horizontal direction toward the rear wall It. With this arrangement of the furnace chamber and tube bank, the fuel is burned in suspension while traveling longitudinally through the furnace chamber and the heating gases generated enter the rear portion of the space occupied by the tube bank and flow forwardly therein through serially connected gas passes formed by transverse baflles 25 and 26 to a heating gas exit at the front end of the setting.

One of the main advantages of a steam boiler of this type is the relatively long path of travel inherently provided for the burning fuel in the furnace chamber before traversing the tubes in the main bank. For higher capacity boilers of this type the drums and tube bank are lengthened with a corresponding increase in the length of the furnace chamber. In view of the relatively high rates of heat release ordinarily required, such furnaces are desirably fluid cooled. The provisions for this purpose ordinarily include a water cooled floor formed by a row of tubes 30 extending laterally from the lower drum II at a slight outward inclination to a header 3| extending along'the lower portion of the side wall IS, with the intertube spaces closed to form a flat floor by metallic bloc 32 held in thermal contact with the tubes 30. An ash pit 33 having a sectional hopper bottom extends across the rear end of the furnace chamber. Access openings 34 are provided either in the front or rear wall, or in both, through which a steam lance or cleaning implement could be inserted for moving ash depositing on the furnace floor rearwardly into the ash pit 33. As the length of furnace floor increases it becomes more difficult to remove the deposited ash in this manner, as a steam lance is effective for only a relatively small distance and the difficulty of manipulating cleaning implements increases. In such high capacity furdrum by side wall tubes 35".

naces some of the ash is separated from the b ing fuel stream in localized high temperature portions of the furnace and tends to deposit on the floor in a viscous or molten condition. Such 5 high temperature zones usually occur a substan- 15 from the header 3| and'bent across the furnace roof for connection to the upper drum I l. The .-front wall llisfluid cooled byarowof baretubes 3' extending upwardly from a transverse header I! connected to the lower drum, with the upper 50 ends of the tubes 16 bent and connected to the upper drum II. A stepped floor construction is advantageously .employed for the furnace bottom, as hereinafter described. As shown, the floor is divided into a front upper section II and ggarearlowersectionflterminatingattheash pit 33. The upper section is formed by the tubes 30 and blocks 32 as described, and extends approximately half the length of the floor. The lower floor section is formed by a row of similarly 30 arranged tubes ll extending between a header 40 extending along the inner side of and below the lower drum Ii and a parallel header 4| in the lower portionof the side wall It. The intertube spaces are closed by metallic tube blocks 32' 35 to form a flat substantially horizontal floor extending from the rear end of the upper section to the ash pit 33. The header 40 receives a fluid supply from the drum ll through curved nipples 42 and the header 4| is connected into the upper The rear wall I4 is protected by a row of bare tubes 44 extending upwardly from a header 45 at the lower floor level to the upper drum ID, the header 45 receiving its fluid supply from the lower drum.

45 Ash particles separating from the burning fuel streams and depositing on the stepped floor may be readily removed through the operation of cleaning fluid discharge provisions associated with each floor section. The deposited ash can 50 be blown from the upper floor section onto the lower floor section by means of transversely spaced discharge nozzles 50 detachably mounted in the first row of floor blocks, as shown in Fig. 4, and having arcuately spaced discharge orifices 55 5I- therein communicating with a passage 52 through the corresponding block. The passages 52 are connected to a common supply header 53 receiving a regulable supply of steam or air from any convenient source. With the described construction and location, the nozzles 50 will be adequately protected from overheating. The vertical wall section 54 of the furnace bottom between the two floor sections is protected by a row of vertically spaced stud tubes 55 andree fractory, with the tubes 55 extending between a vertical header 56 at the front end of the header 40, and a similar vertical header 51 at the front end of the header 4|. The header 56 is iconnected with the lower drum H by one or more 70 nipples 42' and the header 5! to the upper drum I 0 by a wall tube 35" to provide a fluid circulation through the tubes 55. v

The cleaning fluid provisions for the lower floor section advantageously consist of nozzles 8| ex- 75 tending through the vertical wall section 54 at ends arranged to discharge fluid Jets directedrearwardly across the lower floor section. The nozzles 40 are connected to a common supply header II, which in turn is connected to a regulable supply of steam or air. With this arrangement the cleaning nozzles III and 80 can be continuously or intermittently operated to sweep the deposited ash from their respective sections of the floor. The nozzles may also be successively operated to first clean theupper floor section and then the lower floor section.

The forward portion of the lower drum ll adiacent the upper floor section is adequately protected from overheating by the location of that door section at the level of the connections of the corresponding portion of the partition tubes II to the drum. The rear portion of the drum however is above the level of the rear floor section. To protect the drum the partition tubes 2| opposite the lower floor section have their lower ends connected to the header 4!] and a refractory wall 84 is positioned between these tubes and the drum, as shown in Fig. 1. Certain tubes I! in the inner portion of the tube bank at the rear ofthe baffle 25 are bent inwardly, and forwardly and provided with studs and re-' fractory to form a wing wall extension 65 of the partition Ill. The lower ends of the tubes l2" also extend downwardly alongside the drum II and are connected to the header 40. The wing wall causes the heating gases to pass between its rear end and the rear wall before entering the main tube bank, thereby increasing the length of the gas flow path in the furnace chamber.

The floor construction described is particularly useful in integral furnace type boilers as the inherently highratio of cold wall area. to furnace volume facilitates the maintenance of a normal mean temperature therein below the fuel ash fusion temperature, so that substantially all of the ash particles separated in the furnace chamber will be in a. dry condition. Any ash particles separating in a molten condition due to localized high temperature conditions will be mainly above the lower floor section. Such particles have a somewhat longer vertical travel through the furnace chamber before reaching the lower floor section and a correspondingly greater time interval to become chilled and deposit in a dry condition. Having the rear floor section at the lower level reduces the radiant heat effect on the ash deposited thereon and permits the same to be maintained in a dry condition.

While in accordance with the provisions of the statutes I have illustrated and. described herein the best form of my invention now known to me, those skilled in the art will 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 furnace for burning finely divided fuel in suspension comprising a horizontally extending furnace chamber of substantial length, means for introducing a stream of finely divided fuel into the front end of said furnace chamber, a gas exit at the rear end of said furnace chamber, a stepped ash receiving floor for said furnace chamber comprising a front upper section and a rear lower'section, each floor'section comprising a row of spaced water tubes and means closing the intertube spaces of said floor tubes'and defining a substantially flat horizontally arranged floor surface, and means for discharging jets of cleaning fiuidrearwardly across the surface of each section.

2. A furnace for burning finely divided fuel in suspension comprising a horizontally extending furnace chamber of substantial length, means for introducing a stream of finely divided fuel into the front end of said furnace chamber, a gas exit at the rear end of said furnace chamber, an ash pit extending across the rear end of said furnace chamber, a stepped ash receiving floor for said furnace chamber comprising a front upper section and a rear lower section terminating at said ash pit, each floor section comprising a row of spaced water tubes and means closing the intertube spaces of said floor tubes and defining a substantially flat horizontally arranged floor surface, and means for discharging jets of cleaning fluid rearwardly across the surface of each section.

3. A furnace for burning finely divided fuel in suspension comprising a horizontally extending furnace chamber of substantial length, means for introducing a stream of finely divided fuel into thefront end of said furnace chamber, an ash pit at the rear end of said furnace chamber, a stepped ash receiving fioor for said furnace chamber comprising a front upper section and a rear lower section terminating at said ash pit, each of said floor sections including spaced water tubes. and means closing the intertubespaces and defining a fiat ashreceiving surface, and means for discharging jets of cleaning fluid rearwardly across the surface of each section.

4. A steam boiler comprising a horizontally elongated furnace chamber, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of spaced water tubes and means closing the intertube spaces and defining a flat horizontally arranged fioor surface, an ash pit at the rear end of said lower floor section, a vertically disposed wall extending between said floor sections, a row of vertically spaced tubes extending along said wall, and conduits connecting said wall tubes into the boiler circulation system.

5. A steam boiler comprising upper and lower longitudinally extending drums, a bank of vertically disposed tubes connecting said drums, a partition extending along one side of said tube bank and forming the inner side of a furnace chamber laterally adjoining said tube bank and opening thereto at its rear end only, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped ash receiving fioor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a rowof transverse water tubes connected to said lower drum and blocks closing the intertube spaces of said floor tubes and defining a substantially flat horizontally arranged floor surface, and an ash pit at the rear end of said lower floor section.

6. A steam boiler comprising upper and lower longitudinally extending drums, a bank of vertically disposed tubes connecting said drums, a partition extending along one side of said tube bank and forming the inner side of an elongated furnace chamber laterally adjoining said tube bank and opening thereto at one end, means at the front end of said furnace chamber for in troducing and burning a stream of finely divided fuel in suspension, a stepped ash receiving floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of spaced water tubes and means closing the intertube spaces of said floor tubes and defining a substantially fiat horizontally arranged floor surface, an ash pit at the rear end of said lower floor section, and means for discharging jets of cleaning fluid rearwardly over the surface of each floor section.

7. A steam boiler comprising upper and lower longitudinally extending drums, a bank of vertically disposed tubes connecting said drums, a partition extending along one side of said tube bank and forming the inner side of an elongated furnace chamber laterally adjoining said tube bank and opening thereto at one end, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped ash receiving floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of transverse water tubes connected to said lower drum and means closing the intertube spaces of said floor tubes and defining a fiat ash receiving surface, an ash pit at the rear end of said lower floor section, and means at the front end of each floor section for discharging jets of cleaning fluid rearwardly over the surface of the corresponding floor section.

8. A steam boiler comprising upper and lower longitudinally extending drums, a bank of ver-' tically disposed tubes connecting said drums, a partition extending along one side of said tube bank and forming the inner side of an elongated furnace chamber laterally adjoining said tube bank and opening thereto at one end, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped floor for said furnace chamber having a front upper section and a rear lower section, said upper floor section comprising a row of transverse water tubes directly connected to said lower drum, said lower floor section comprising a row of transverse water tubes, longitudinally extending headers connected to opposite ends of said last named tubes,

conduits connecting said headers into the boiler circulation system, an ash pit at the rear end of said lower floor section, and means at the front end of each floor section for discharging jets of cleaning fluid rearwardly over the surface of the corresponding floor section.

9. A steam boiler comprising upper and lower longitudinally extending drums, a bank of vertically disposed tubes connecting said drums, a

partition extending rearwardly along one side of said tube bank and forming the inner side of a horizontally elongated furnace chamber laterally adjoining said tube bank and opening thereto at one end, means at the front end of said furnace chamber for introducing and burning a stream of flnely divided fuel in suspension, a stepped floor for said furnace chamber having a front upper section and a rear lower section, an ash pit at the rear end of said lower floor section, a vertically disposed wall extending between said floor sections, a row of vertically spaced tubes extending along said wall, and conduits connecting said wall tubes into the boiler circulation system.

10. A steam boiler comprising upper and lower l tudinally extending drums, a bank of verti- 1y disposed tubes connecting said drums. a

tion extending rearwardly along one side of said tube bank and forming theiinner side of a horizontally elongated furnace chamber laterally adjoining said tube bank and opening thereto at one end only, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of transverse water tubes connected to saidlower drum, an ash pit at the rear end of said lower floor section. a vertically disposed wall extending between said floor sections, vertical headers at opposite ends of said wall, a row of vertically spaced tubes extending between said headers, and conduits connecting said headers into the boiler circulation system.

11. A steam boiler comprising upper and .lower longitudinally extending drums, a bank of vertically disposed tubes connecting said drums, a partition extending rearwardly along one side of said tube bank and forming the inner side of an elongated furnace chamber laterally adjoining said tube bank and opening thereto at its rear end,

means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped floor for said furnace chamber having a front upper section and a rear lower section, each fioor section comprising a row of transverse water tubes connected to said lower drum, an ashpit at the rear end of said lower floor section, a row of water tubes defining an angularly arranged extension of the rear end of said partition and having their lower ends extending downwardly in front of said lower drum, a header at the level of said lower floor section connected to the lower ends of said last named tubes, and means connecting said header and last named tubes into the boiler circulation system.

12. A steam boiler comprising a horizontally elongated furnace chamber, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped ash receiving floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of spaced transversely extending water tubes and blocks closing the intertube spaces of said floor tubes and defining a fiat horizontally arranged floor surface, a vertically disposed wall extending between said floor sections, an ash pit at the rear end of the lower floor section, and means at the front end of each floor section for discharging Jets of cleaning fluid rearwardly over the surface of the corresponding fioor section comprising fluid jet nozzles mounted in the blocks of said upper fioor section and fluid Jet nozzles extending through said vertically disposed wall.

13. A steam boiler comprising upper and lower longitudinally extending drums, a bank of vertically disposed tubes'connecting said drums, a partition extending along one side of said tube bank and forming the inner side of a furnace chamber laterally adjoining said tube bank and opening thereto at one end only, means at the front end of said furnace chamber for introducing and burning a stream of finely divided fuel in suspension, a stepped ash receiving floor for said furnace chamber having a front upper section and a rear lower section, each floor section comprising a row of spaced transversely extending water tubes connected to said drums and blocks closing the intertube spaces of said floor tubes and defining a fiat horizontally arranged floor surface, a vertically disposed wall extending between said floor sections, an ash pit at the rear end of the lower floor section, and means at the front end of each floor section for discharging jets of cleaning fluid rearwardly over the surface of the corresponding floor section comprising fiuid Jet nozzles mounted in the blocks of said upper floor section and fluid jet nozzles extending through said vertically disposed wall.

FLEWIS w. Karma.

Images