US2243862A

US2243862A - Steam generator

Info

Publication number: US2243862A
Application number: US196120A
Authority: US
Inventors: Lewis W Heller
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1938-03-16
Filing date: 1938-03-16
Publication date: 1941-06-03
Anticipated expiration: 1958-06-03

Description

June 3, 1 941. L. w. HELLER 2,243,852

STEAM GENERAT OR 7 Filed March 16, 1938 3 Sheets-Sheet 1 INVENTOR Lewis WHe/ler June 3, 1941. w HELLER 2,243,862

STEAM GENERATOR Filed March 16, 1938 3 Sheets-Sheet 2 & l\ Q Q 00b oooooooooono INVENTOR.

Lewis W Hal/e2 June 3, 1941.-

L w. HELLER 12,243,862

STEAM GENERATOR 7 Filed March 16, 1938 3 Sheets-Sheet 3 Fig 5 4/ W4? 59 fi 6 13 12 25 I 139 D Mi Q 1 25 Q 24 i 26 27 z-%/w//mfi%' INVENTOE. Lewis WHe/[er ATTORNEY.

Patented June 3, 1941 STEAM GENERATOR Lewis W. Heller, East Orange, N. J assignor to The Babcock & Wilcox Company, Newark, N. J., a corporation of New Jersey Application March 16, 1938, Serial No. 196,120

11 Claims.

This invention relates to the construction and operation of steam generators of the integral furnace type, i. e., a steam generator having its furnace chamber laterally adjoining the main bank of steam generating tubes. In steam generators of this type the furnace chamber and space containing the main tube bank are usually separated except at one end, and the fuel burning means located at the opposite end of the furnace chamber. Such an arrangement generally provides a path of flame travel of adequate length in the furnace chamber with some units using certain fuels and burners, but for higher steam generating and fuel burning capacities or limitations in the floor space available, or with other fuels or burners, a longer path of flame travel is desirable to insure the desired completeness of combustion within the furnace chamber before the gases reach the tube bank and steam superheating tubes.

The main object of my invention is the provision of a steam generator of the type described with an improved construction and arrangement of the furnace and tube bank chambers and associated fluid heating parts affording a relatively long path of flame travel before the heating gases enter the tube bank and a thermally effective heating gas flow over the convection heated surface, While maintaining a compact construction having low floor space and head room requirements.

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 section taken on the line -'-'l of Fig. 2 illustrating somewhat diagrammatically one embodiment of the invention;

Fig. 2 is a horizontal section taken on the line 22 of Fig. 1;

Figs. 3 and 4 are longitudinal vertical sections taken on the lines 3-3 and 5-4 respectively of Fig. 1; and

' Fig. 5 is a vertical section taken on the line 5-5 of Fig. 2.

The steam generating unit illustrated com prises a setting substantially rectangular inhorizontal and vertical cross-section including a front 5 wall [0, a rear wall ll, side walls I2 and I3, and roof I4. A lower drum [5 is horizontally arranged along the lower part of the side Wall l3 and above the bottom of the furnace chamber. A

. steam and water drum 16 extends parallel to the maining portion serving as the furnace chamber of the unit.

The furnace chamber is defined by the side wall I2 and portions of the walls In and II and roof II. The furnace chamber walls are fluid cooled, the fluid cooling provisions comprising front wall tubes 89 and rear wall tubes 20' lining the front and rear walls respectively. The tubes l9 and 20 have their upper ends bent laterally into the upper drum I 6 andtheir lower ends connected to headers 25 and22 respectively connected to the drum l5. The side wall [2 and roof [4 are cooled by a row of tubes 23 extending from a lower side wall header 24 to the upper drum IS. The bottom of the furnace chamber is defined for substantially its entire length by a fluid cooled floor 25 formed by a row of block covered tubes 26 extending from the header 24 toa similar header 2! below the drum [5. The floor 25 extends from the rear wall I l and terminates short of the front wall, the remaining portion of the furnace chamber bottom being formed by an ash pit 29.

The partition-forming means separating the furnace chamber from the tube bank space comprise a row of tubes 35 at the inner side of the tube bank extending downwardly from the drum IS. The tubes 35 in the rear portion of the tube row 35 continue downwardly and are connected to the 'subjacent tubes 26 by incorporating an intermediate floor header 28 in the rear portion of the tube row 26. The remaining tubes 35 are bent laterally toward the drum l5 and thence along the lower portion l3 of the side Wall l3 to the header 21. The tubes 35 and 35 are partially studded to support refractory clos-' ing. the intertube spaces and thus form a partition 31 having a vertically extendin upper portion, a vertical lower rear portion 31* and a laterally inclined front portion 31 The partition construction described thus defines a furnace chamber having a laterally extending leg over a major portion of its length from the front wall rearwardly and an entrance into the tube bank space behind the partition section 31.

The partition construction described is especially adapted for the provision of a relatively tubes in the tube now 23 are bent, as shown in Fig. 3, in an inclined plane in spaced relation across the burner port. A pair of pulverized fuel burner nozzles M of the multiple-outlet type are arranged side-by-side in the burner port with the burner outlets having their longitudinal axes intersecting the axes of the corresponding tube portions, whereby the streams of primary air and pulverized fuel issuing from the nozzles are divided by the subjacent tube portions and pass through the intertube spaces into the furnace chamben A secondary air casing 42 encloses the burner nozzles 4| and burner port 40 and provides a stream of. secondary air around the burner outlets and through the inter-tube spaces. With this construction streams of pulverized fuel and combustion air are directed downwardly and forwardly in the furnace chamber. Combustion will proceed at a relatively rapid rate, and the products of combustion flow laterally below the partition section 31 and rearwardly behind the partition section 3'! into the bottom of the' tube bank space. Y

The tube bank space is advantageously divided into a plurality of serially connected passes by the baffle system hereinafter described. As shown in Fig. 1, the tubes ll forming the outermost row of tubes have their upper portions bent laterally to the side wall l3 before entering the drum. l6. Bafile blocks are arranged to form a baffle 45 following the configuration of. the tubes I! from the lower drum l5 to the upper part of the rear wall l3,the bent upper portion of the tubes I'I serving to support the baffle blocks. The baffle 45 extends from the front wall rearwardly to the same extent as the partition section 31*. A vertical bafile 461 extends downwardly through the tube bank to its full extent and laterally from the partition 31 to the full width of the tube bank, and also closes the rear end of the space within the baffle 45. The space between the baffle 4B and the rear wall ll forms a gas pass 50 through which the heating gases flow upwardly and then forwardly through the triangular space defined by the upper portions of the tubes H at the outer side of the bafile 46. This triangular space is closed at 'a point forwardly of the battle 46 by a second transverse baflle 41 which also extends the full width of the tube bank and terminates atits lower end across the inclined portion of the tubes ll, as indicated in Fig.1. The bafile 41 thus divides the space forwardly of the baflle 46 into a second pass 5|. through which the heating gases flow downwardly and laterally, and a third gas pass 52 through which the heating gases flow laterally and upwardly to a gas outlet 53 at the front end of the tube bank space.

The portion of the tube bank I! in the first gas pass 50 is formed by a small number of tube rows I'l of larger diameter than the remaining tubes in the bank. The inclined portions of the tubes in the two lower rows l'l are spaced and arranged, as shown in Fig. 4, to provide a slag screen across the entrance to the first pass 50.

- over the baffle 35 into the second pass 5|.

The remaining portion of the gas pass is 00- cupied by a group of vertical superheater tube coils arranged in a multiple horizontal loopedi formation. Each superheater tube coil has its; horizontally extending legs interconnected by; supporting lugs 56 and the coil is suitably sup-- ported as a whole at opposite ends from the: adjacent tubes ll and wall IS. The upper ends: of the superheater tube coils 55 are connected! to the steam space of the drum l6, while their: lower ends are connected to the steam main.. With this arrangement of the heating surface in: the first pass the heating gases flow upwardly/ over the tubes IF and superheater tubes, then: around the upper portion of the bafile 46 and. The: gases flow downwardly therein along the tubes: I! and around the lower end of the bafile 41 into the third pass 52, wherein the gases flow upwardly through the tube bank opposite to the gas flow in the pass 5i.

With the arrangement of the generating tubes; N and superheater coils illustrated, the heating gases flowing upwardly through the first pass 50 may tend to short-circuit part of the superheating surface due to the greater gas flow area in the pass adjacent the partition 31. The distribution of the heating gases and thereby the amount of superheating effected is controlled, as shown in Fig. 5, by the arrangement of a vertical baflie 58 at the inner end of the superheater coils. The baiile divides the gas pass 50 longitudinally and terminates short of the drum 16, with the space therebetween controlled by a pivoted damp-- er 59 adapted to be externally operated. The position of. the damper will control the amount of heating gases passing upwardly between the partition 31 and baflle 58.

- The described steam generator construction provides a somewhat reverberatory flame path of substantial length in the furnace (:hamber, which expedites combustion and insures an adequate length of flame travel at high rates of fuel introduction. The particular tube bank and baflle formation employed permits this long flame path in the furnace chamber, and also provides a. thermally effective flow of heating gases convection heated surface.

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,

nace chamber extending along the outer side of and partly below the L-shaped space containing said tube bank and communicating there with adjacent one end thereof, and means for burning fuel in said furnace chamber and causing a flow of heating gases from said furnace chamber longitudinally of the L-shaped space containing said tube bank.

2. A steam generator comprising an upper horizontally elongated drum and a laterally dis-- over the placed lower drum, a bank of L-shaped steam generating tubes connecting said drums, partition means separating the space containing said L-shaped tube bank from one side of a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, and means at the communicating end of said furnace chamber for discharging a stream of fluid fuel in said furnace chamber and burning the fuel in suspension therein.

3. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes connecting said drums, partition means defining one side of a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, means at the communicating end of said furnace chamber for discharging a stream of fluid fuel in said furnace chamber and burning the fuel in suspension therein, and means defining a plurality of serially connected vertical gas passes longitudinally of said tube bank.

4. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes connecting said drums, means defining a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, said means comprising a fluid cooled partition extending downwardly from said upper drum and divided into a portion extending laterally below said tube bank and a portion extending vertically to the bottom of said furnace chamber, and means for burning fuel in suspension in said furnace chamber.

5. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes connecting said drums, means defining a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, said means comprising a row of partition-forming water tubes extending downwardly from said upper drum and divided into a group of L-shaped tubes extending laterally below said tube bank and a group of vertical tubes extending to the bottom of said furnace chamber, means closing the intertube spaces of said partition tubes, and means for burning fuel in said furnace chamber.

6. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes connecting said drums, means defining a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, said means comprising a partition extending downwardly from said upper drum and having a portion extending laterally below said tube bank, means for burning fuel in said furnace chamber, and means defining a plurality of serially connected vertical gas passes longitudinally of the space containing said tube bank.

'7. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes connecting said drums, means defining a furnace chamber extending along one side of and partly below the space containing said tube bank and communicating therewith adjacent one end thereof only, said means comprising a partition extending downwardly from said upper drum and having a portion extending laterally below said tube bank and a portion extending vertically to the bottom of said furnace chamber, means for burning fuel in said furnace chamber, and means defining a plurality of serially connected vertical gas passes longitudinally of the space containing said tube bank, said last named means including a horizontally disposed V-shaped baffle at the opposite side of said tube bank, and a pair of vertically disposed baffles extending between said partition and said V-shaped baffle.

3. A steam generator comprising an upper horizontally elongated drum and a laterally displaced lower drum, a bank of L-shaped steam generating tubes having laterally extending lower portions connected to the lower drum and vertically extending upper portions connected to the upper drum, means separating the space containing said L-shaped tube bank from a furnace chamber extending along one side of and partly below the space containing said tube bank, said means including a partition extending downwardly from said upper drum at the furnace chamber side of said tube bank and having a lower portion extending laterally below said tube bank, a heating gas outlet from said furnace chamber into said tube bank space arranged below said laterally extending tube portions and providing a heating gas flow upwardly across said laterally extending tube portions, and means for burning fuel in said furnace chamber.

9. A steam generator having walls forming a setting, a horizontally elongated steam and water drum, means forming a furnace chamber in said setting having a lateral extension and partly separated from a convection space in said setting located above said furnace chamber extension, said means including L-shaped steam generating tubes having vertically extending upper portions connected to said drum and closure means cooperating with said L-shaped tubes to form a partition extending downwardly from said drum at the furnace chamber side of saidconvection space and having a lower portion extending laterally below said convection space, a gas outlet in said partition lower lateral portion. connecting said furnace chamber extension to said convection space, fluid heating tubes arranged in said convection space, and baffle means dividing said convection space into serially connected upflow and downflow heating gas passes below the level of said drum and containing said fluid heating tubes.

10. A steam generator having walls forming a setting, a horizontally elongated steam and water drum, means forming a furnace chamber in said setting having a lateral extension and partly separated from a convection space in said setting located above said furnace chamber extension, said means includin L-shaped steam generating tubes having vertically extending upper portions connected to said drum and closure means cooperating with said L-shaped tubes to form a partition extending downwardly from said drum at the furnace chamber side of said convection space and having a lower portion extending laterally below said convection space, a gas outlet at one end of said partition lower lateral portion connecting said furnace chamber extension to said convection space, baflie means dividing said convection space into an upfiow heating gas pass opening to said gas outlet and a serially connected downflow heating gas pass extending below the level of said drum, fluid heating tubes located in said heating gas passes, and a group of said L-shaped tubes having their lower portions arranged to form a tube screen across said gas outlet.

11. A steam generator having walls forming a. setting, a horizontally elongated steam and water drum, means forming a furnace chamber in said setting having a lateral extension and partly separated from a convection space in said setting located above said furnace chamber extension, said means including L-shaped steam generating tubes having vertically extending upper portions connected to said drum and closure means cooperating with said L-shaped tubes to form a partition extending downwardly from said drum at the furnace chamber side of said convection space and having a lower portion extending laterally below said convection space, a gas outlet from said furnace chamber extension upwardly into said convection space, fluid heating tubes arranged in said convection space, baflles dividing said convection space into serially connected upfiow and downflow heating gas passes containing said fluid heating tubes, a bank of steam heating tubes located in an upflow pass opening to said gas outlet, and a damper controlled by-pass passage arranged in parallel with said upflow pass.

LEWIS W. HELLER.