US2186919A

US2186919A - Steam boiler

Info

Publication number: US2186919A
Application number: US86905A
Authority: US
Inventors: Ervin G Bailey
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1936-06-24
Filing date: 1936-06-24
Publication date: 1940-01-09
Anticipated expiration: 1957-01-09

Description

E. G. BAILEY STEAM BOILER Jan. 9, 1940.

Filed June 24, 1936 5 Sheets-Sheet 1 r I ,7 WI by??? INVENTOR. Ervin G Bailey wg wl V ATTORNEY.

n 9, 1940. 5G. BAILEY 2,18 ,9 9

STEAM BOILER Filed June 24, 1936 5 Sheets-Sheet 2 ATTORNEY.

E. G. BAILEY Jan. 9, 1940.

STEAM BOILER Filed June 24, 1936 5 Sheets-Sheet 3 INVENTOR. Er'vz'n G. Bailey ATTORNEY.

7 J E. s. BA ILEY 2,186,919

STEAM BOILER Filed June 24, 1956 5 Sheets- Sheet 4 1 I IIH HP H 1 \17 INVENTOR. 1 Irvin GBaiZey B ATTORNEY.

Jan. 9, 1940.

E. G. BAILEY STEAM BOILER Filed June 24, 1936 5 Sheets-Sheet 5 O OOO 00000O000W0000O0O00 0 0 mvsmon Erz/m G. Bazley m ATTORNEY.

Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE STEAM BOILER Application June 24, 1936, Serial No. 86,905

17 Claims.

The present invention relates to the construction and operation of water tube steam boilers of moderate capacity of the general type disclosed in my prior joint Patent No. 1,999,984, and which type of boiler is characterized by its low floor space and head-room requirements, reliability, low draft loss, high efliclency, and relatively low cost of construction and maintenance.

One object of the present invention is the provision in a steam boiler of the character described of an improved arrangement of the fuel burning means relative to the furnace chamber, and of the provisions for removing ash deposited in the furnace chamber. Another object is the provision of a novel path of flow of the heating gases relative to the convection heated steam generating surface of the boiler. Another object is the provision of water cooled means for increasing the effective furnace length, and effecting better distribution of the furnace gases and shielding of the tube bank from furnace radiation.

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 under-- standing of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of my invention.

Of the drawings: Fig. 1 is a somewhat diagrammatic perspective view with parts broken away and in section illustrating one embodiment of my invention;

Fig. 2 is a sectional elevation taken on the line 22 of Fig. 1; v

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

Fig. 4 is a sectional elevation of a modified construction;

Fig. 5 is a horizontal section taken on the line 5-5 of Fig. 4; and

Fig. 6 is an enlarged view of a portion of the wing wall shown in Fig; 5.

In the steam boiler unit illustrated in Figs. 1 to 3 a vertically disposed front wall In, rear wall H, and opposite side walls l2 and I3 unite to form a setting of substantially rectangular cross-section. The top of the setting is formed by a partly inclined roof or arch H. The space enclosed by the setting is divided into a horizontally elongated furnace chamber and a laterally adjoining space containing a steam generating tube bank. The pressure parts of the boiler include a pair of upper and lower drums l6 and II respectively, which extend substantially the full length of the setting in parallel offset relation, and are connected by a bank of vertically disposed water tubes I 8. The innermost longitudinal row of tubes Ill of the tube bank has its intertube spaces for a portion of its length closed by suitable refractory material to form a gas-tight partition l9 extending the full height of the tube bank and from the front wall "I towardsthe rear wall H. The partition separates the furnace chamber from the space containing the tube bank except along the rear portions thereof.

The walls of the furnace chamber are desirably water cooled. As shown, a row of tubes 20 extends from the drum I! at a slight inclination laterally across the bottom of the furnacechamber, with the spaces therebetween closed by suitable blocks 2| to form a smooth floor for the furnace chamber. The tubes 20 are connected at their outer ends to a longitudinally extending header 22 at the lower end of the side wall 12. The inner portion of the side wall I2 is formed by a row of spaced vertical tubes 23 with refractory therebetween, bent at their upper ends and inclined inwardlyacross the arch M to the upper drum I 6. The cooling provisions for the front and rear walls I0 and II consist of a pair of inclined bottom headers 25 connected at one end to the drum I1 and along their lengths to the upper drum I6 by a row of vertically disposed tubes 26 extending upwardly along the inner side of the corresponding wall and bent laterally at their upper ends into the upper drum l6.

The furnace chamber construction described is particularly adapted for the burning of fluid fuel, such as pulverized coal, gas, or oil, in suspension. In the construction shown, a pair of pulverized coal burners are advantageously arranged to discharge downwardly through the furnace roof at longitudinally spaced points adjacent the front wall l0. As shown in Figs. 1 and 2, each fuel burner comprises a pulverized coal and primary air conduit 30 terminating in a series of transversely spaced tapering nozzles 3| spaced along the roof tubes 23 and enclosed by a sectional air box 32, which registers with a burner port 33 formed by omitting the intertube refractory over a portion of the roof tubes. The air box 32 is supplied with secondary air for combustion, preferably preheated, through a conduit extention 34 at one side thereof, with the supply of air from the conduit 34 to each section of the air box controlled by suitable dampers 35. Each fuel discharge nozzle 3| extends transversely across a plurality of roof tubes, as shown in Fig. 2. The corresponding subjacent roof tubes are provided with tube protectors 36 on their upper sides to minimize erosion of the tubes by the entering fuel streams. vided by the subjaeent tube portion into a plurality of initially separate streams. The secondary air supplied to the air box passes downwardly Each fuel stream is thus subdi through the burner port between and around the fuel nozzles.

With the described burner arrangement the pulverized coal will be discharged downwardly into the furnace chamber in a multiplicity of small streams which will be rapidly ignited, and the burning fuel stream and heating gases generated will pass rearwardly in the furnace chamber in a generally horizontal path and around the rear end of the partition l9 into the tube space. A relatively long flame path for the fuel will be thus provided of a character contributing to the separation of ash particles during the flame travel which deposit on the floor of the furnace chamber. To facilitate ash removal, the floor is terminated adjacent both the front and rear walls of the furnace chamber and an ash trench or pit 31 formed between each end of the floor and the adjacent wall. As shown in Fig. 2, the ends of the floor project beyond the corresponding end of the ash pits 31. The end floor tubes 2|! each have an inclined plate 38 welded thereto along its exposed side, forming a slag drip ledge and also reducing the amount of exposure of the refractory walls of the ash pit'to slag erosion. Door closed openings II and 42 are provided in both the front and rear walls at levels above and below the floor to facilitate removal of the deposited ash from the floor and the adjacent ash pits.

As shown in Figs. 1 and 3, the tube bank is divided into three longitudinal sections by transversely extending vertical bailles 50 and 5|. The baffle 50 extends outwardly from the rear end of the partition l9 to a point spaced from the side wall I 3 and unites with the adjacent portions of the setting to provide a gas pass 52 open along its inner side to the furnace chamber. The innermost rows of boiler tubes l8 in this pass are spaced to form a slag screen across the entrance to the pass, while the remaining boiler tubes l8 in the pass are arranged with standard spacing. In the outer portion of the first pass is arranged a group of inverted U-shaped superheater tubes 53. The remaining tubes in the tube bank are preferably of smaller diameter'than the water tubes in the first pass and the partition tubes l8.

While the heating gases pass generally horizontally across the tubes in the first pass, the remaining portion of the tube space is divided into a pair of vertical gas passes. The provisions for this purpose comprise the vertical transverse baflle 5| extending the full width of the tube space between the partition I! and the side wall l3, and a longitudinally extending vertical baflie 54 extending along the outer side of the tube bank from the outer end of .the bafile 50 to the front wall It. Boiler tubes l8 are thus located in the second pass 55 and tubes |8 in the third pass 55. The longitudinal baflle 54 has an opening 51 adjacent the bottom of the second pass 55 to provide a passage for the entry of heating gases into the second pass. The portion of the transverse bame 5| inwardly of the baflie is terminated at its upper end substantially below the level of the drum l5 to provide an opening between the second and third passes. The lower portion of the baflle 54 opposite the third pass 55 is also cut away to provide communication between the third pass and a gas outlet 58 formed in the lower forward end of the side wall I3.

With the described construction and arrangement of the parts, the heating gases enter the first pass 52 throughout its height and flow successively across the slag screen tubes I5 the tion of the baffle 5| into the third pass 55. The

heating gases flow downwardly along the boiler tubes in the third pass and outwardly below the lower end of the corresponding portion of the baflle 54 to the gas outlet 59.

In the modified construction illustrated in Figs. 4 and 5, a row of tubes 50 is arranged partly in front of and at an oblique angle to the rows of water tubes |8 forming the slag screen. The row of tubes 60 have bent end portions 50 of progressively increasing length rearwardly of the boiler connected to the drums l6 and I! in the same manner as the partition tubes, and straight intermediate portions 50' of progressively decreasing length rearwardly arranged in alignment in a plane inclined vertically and longitudinally toward the side wall I! from the end of the partition IS. The bent end portions 50' are arranged so that the straight portions will be forwardly offset from the corresponding drum tube openings, whereby the rearmost straight portion 50 will be spaced a predetermined distance from the rear wall The tube straight portions are provided with suitable means, such as rows of projecting studs as shown in Fig. 6, along their adjacent sides over substantially their entire length for supporting refractory material 5| for closing the intertube spaces. A water cooled wing wall or deflector baflle extending from the rear end of the partition partly across the entrance to the first gas pass 52 is thus formed.

This arrangement provides a long flow path for the heating gases in the furnace chamber, avoiding short circuiting of the flame and high carbon loss. The gases flow mainly around the rear end of the baffle, and also above and below the same across the tube portions In this flow path. the heating gases are caused to converge and mix in the rear section before entering the narrow passage between the batlle and rear wall, and then diverge into the flaring space between the baflle, rear wall, and slag screen tubes IS. The distribution of the heating gases entering the flrst pass is improved and the tubes therein eflectively shielded from furnace radiation. With this arrangement, the rear wall cooling tubes 25 may be concentrated, if desired, along the portion thereof between the baffle and side wall l2.

While in accordance with the provisions of the statutes I have illustrated and described herein the best forms 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 gas passes, said baiile means including a vertical baflie extending from the rear end of said partition transversely of said tube space and a second vertical bailile extending forwardly from said first bafllle at the outer side of said tube bank and having an opening in the lower portion thereof for the passage of heating gases upwardly along the tubes in the adjacent portion of said tube bank and means for burning fuel in said furnace chamber and generating heating gases flowing through said furnace chamber and thence through said tube space.

2. A steam boiler having a pair of horizontally disposed upper and lower drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, means including a vertically disposed partition alongside said tube bank forming a furnace chamber laterally adjoining the space containing said tube bank and communicating with the rear portion thereof, baifie means in said tube space arranged to divide said tube space into a plurality of serially connected gas passes, said bafile means including a vertical baffle extending from the rear end of said partition transversely of said tube space, a second vertical baflile extending forwardly from said first baflile at the outer side of said tube bank, and a third vertical bailie extending across said second baflle' to said partition, said second and third baflies having openings therein relatively arranged to effect a heating gas flow upwardly along the tubes between said first and third baflies and downwardly along the tubes forwardly of said third bafile, and means at the front end of said furnace chamber for burning fuel in suspension and generating heating gases flowing longitudinally of said furnace chamber and thence through said tube space.

3. A steam boiler comprising a bank of vertically disposed water tubes, means forming a horizontally elongated furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at one end thereof, means forming a floor for a major portion of said furnace chamber, a fuel burner mounted in' the roof of said furnace chamber and arranged to downwardly discharge fuel into said furnace chamber, and a pair of ash receiving openings extending transversely of said floor adjacent the opposite ends of said furnace chamber.

4. A steam boiler comprising a bank of vertically disposed water tubes, means forming a horizontally elongated furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at the rear end thereof,'means forming a floor for a major por tion of said furnace chamber, a fuel burner mounted in the roof of said furnace chamber at the front end thereof and arranged to downwardly discharge pulverized fuel and air into said furnace chamber, and a pair of ash receiving openings extending transversely of said floor adjacent the opposite. ends of said furnace chamber.

5. A steam boiler having upper and lower horizontally disposed drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, a partition defining the inner 'side wall of a fluid cooled furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at its rear end, means defining the remaining sides and roof of said furnace chamber, means forming a fluid cooler floor for a major portion of said furnace chamber, a row of water tubes extending along the roof of said furnace chamber, a fuel burner mounted in said furnace chamber roof at the front end thereof and arranged to discharge fuel downwardly between said roof tubes into said furnace chamber, and a pair of ash receiving openings extending transversely of said floor adjacent the opposite ends of said furnace chamber.

6. A steam boiler having upper and lower horizontally disposed drums, a bank of vertically 'disposed water tubes connected to said drums along the length thereof, a partition defining the inner side wall of a fluid cooled furnace chamber laterally adjoning the space containing said tube bank and communicating therewith at its rear end,

means dfining the remaining sides and roof of said furnace chamber, means forming a fluid cooled floor for a major portion of said furnace chamber, a row of water tubes extending along the roof of said furnace chamber, rows of water tubes extendingalong the opposite end walls of said furnace chamber, a fuel burner mounted in said furnace chamber roof at the front end thereof and arranged to discharge pulverized fuel and air downwardly between said roof tubes into said furnace chamber, and a pair of ash receiving openings extending transversely of said floor adjacent the opposite ends of said furnace chamber. v

'7. A steam boiler comprising a longitudinally extending bank of vertically disposed water tubes, a partition defining the inner side wall of a furnace chamber laterally adjoining the space containing said tube bankand communicating therewith at its rear end, means defining the remaining sides of said furnace chamber, fuel burning means at the front end of said furnace chamber, and means formin a fluid cooled deflector baflle in said furnace chamber extending at an angle to said partition across the heating gas entrance to said tube space.

8. A steam boiler having upper and lower horizontally disposed drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, a partition defining the inner side wall of a fluid cooled furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at its rear end, means defining the remaining sides of said furnace chamber, fuel burning means at the front end of said furnace chamber, and" means forming a deflector baffle extending from the rear portion of said partition outwardly and rearwardly in said furnace chamber across the heating gas entrance to said tube space and spaced from the rear wall of said furnace chamber.

9. A steam boiler having upper and lower horizontally disposed drums, a. bank of vertically disposed water tubes connected to said drums along the length thereof, a partition defining the inner side wall of a fluid cooled furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at its rear end, means defining the remaining sides of said furnace chamber, fuel burning means at the front end of said furnace chamber, and means forming a fluid cooled deflector bafile in said furnace chamber extending at an angle to said partition outwardly and rearwardly across the heating gas entrance to said tube space, said bathe-forming means including a row of water tubes having bent end portions connected to said upper and lower drums and intermediate straight portions arranged in alignment.

10. A steam boiler having upper and lower horizontally disposed drums, a bank of vertically disposed water tubes connected to said drums along the length thereof, a partition defining the inner side wall of a fluid cooled furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at its rear end, walls defining the remaining sides of said furnace chamber, fuel burning means at the front end of said furnace chamber, means forming a fluid cooled deflector baflle in said furnace chamber extending at an angle to said partition outwardly and rearwardly across the heating gas entrance to said tube space, said bathe-forming means including a row of water tubes having bent end portions connected to said upper and lower drums and intermediate straight portions arranged in alignment, and refractory means arranged to close the spaces between said tube straight portions.

11. A steam boiler having upper and lower horizontally disposed drums, a bank of vertically disposed water tubes connected .to said drums along the length thereof, a partition defining the inner side wall of a. fluid cooled furnace chamber laterally adjoining the space containing said tube bank and communicating therewith at its rear end, means defining the remaining sides of said furnace chamber, fuel burning means at the front end'of said furnace chamber, means forming a fluid cooled deflector bailie extending from adjacent the rear end of said partition outwardly and rearwardly in said furnace chamber across the heating gas entrance to said tube space to a point spaced from the rear wall of said furnace chamber, said banle-forming means including a row of water tubes having bent and portions connected to said upper and lower drums and intermediate closely spaced straight portions arranged in alignment, refractory means arranged to close the spaces between said tube straight portions, and water tubes along the portion of the rear wall of said furnace chamber beyond the rear end of said bame.

12. A steam boiler comprising upper and lower drums, a bank of water tubes connecting said drums, a partition defining the inner side wall of a furnace chamber laterally adjoining the space containing said tube bank and separated therefrom except at one end by said partition, means for burning fuel in said furnace chamber, and a deflector battle in said furnace chamber forming an angular continuation of said partition into said furnace chamber and extending partly across the heating gas entrance to said tube space. v

13. A steam boiler comprising upper and lower drums, a bank of water tubes connecting said drums, means forminga partition defining the inner side wall of a furnace chamber at one side of and communicating with one end of said tube bank space, means for burning fuel in said furnace chamber, and a series of water tubes having vertically disposed aligned portions in said furnace chamber forming an oblique angular continuation of said partition extending partly across the heating gas entrance to said tube space.

14. A steam boiler comprising upper and lower drums, a bank of water tubes connecting said drums, means forming a partition defining the inner side wall of a furnace chamber at one side of and communicating with one end of said tube bank space, means for burning fuel in said furnace chamber, and a continuation of said partition having a series of water tubes connected to said upper and lower drums and having vertically disposed aligned portions arranged in a plane in said furnace chamber extending at an angle to said partition.

15. A steam boiler comprising a bank of vartically disposed tubes, means including a vertically disposed partition alongside said tube bank forming a furnace chamber laterally adjoining the space containing said tube bank and communicating with the rear end thereof, means forming a floor for a major portion of said furnace chamber, a pulverized fuel burner mounted in the roof of said furnace chamber at the front end thereof and arranged to downwardly discharge fuel into said furnace chamber, a pair of ash receiving openings extending transversely of said floor adjacent the opposite ends of said furnace chamber, and banle means in said tube space arranged to divide said tube space into a plurality of serially connected gas passes, said bailie means including a vertical bailie extending from the rear end of said partition transversely of said tube space, and a second vertical bailie extending forwardly from said first baifie at the outer side of said tube bank and having an opening in the lower portion thereof for the passage of heating gases upwardly along the tubes in the adjacent portion of said tube bank.

16. A steam boiler comprising a bank of vertically disposed tubes, means including a ver-- tically disposed partition alongside said tube bank forming a furnace chamber laterally adjoining the space containing said tube bank and communicating with the rear end thereof, a

fuel burner at the front end of said furnace chamber and arranged to discharge fuel into said furnace chamber, a series of water tubes having vertically disposed aligned portions in said furnace chamber forming an oblique angular continuation of said partition extending partly across the heating gas entrance to said tube space, and baille means in said tube space-arranged to divide said tube space into a plurality of serially connected gas passes, said baifie means including a vertical bailie extending from the rear end of said partition transversely of said tube space, and a second vertical bafiie extending forwardly from said first baflle at the outer side of said tube bank and having an opening in the lower. portion thereof for the passage of heating gases upwardly along the tubes in the adjacent portion of said tube bank.

17. A steam boiler comprising spaced water chambers, a bank of water tubes connecting said chambers, a partition defining one side of a furnace chamber adjacent the space containing said tube bank and separated therefrom except at one end by said partition, means for burning fuel in said furnace chamber, and a deflector baflie in said furnace chamber forming an angular continuation of said partition into said furnace chamber and extendingpartly across the heating gas entrance to said tube space.

mvm G. BAILEY.