US1999568A - Steam boiler and furnace - Google Patents

Description

i April 30, .1935.

H. .J. KERR swam BOILER AND FURNACE Filed Sept. 9, 1927 2 Sheets-Sheet l INVENTOR ATTORNEYJ H. J. KERR STEAM BOILER AND FURNACE Filed Sept. 9, 1927 2 Sheets-Sheet 2 April 30, 1935.

F i Z III INVENTOR I'ZQ. LIQU D HEATERS 1,

PORIZERS,

Patented Apr. 30, 1935 Search noun UNITED STATES PATENT OFFICE STEAM BOILER AND FURNACE Howard J. Kerr, Westfield, N. J., assignor to The Babcock & Wilcox Company, Bayonne, N. .L, a corporation of New Jersey Application September 9, 1927, Serial No. 218,416

11 Claims.

My present invention is particularly applicable to furnaces of the type burning finely divided fuel, though it will be understood that my invention is not limited to such use.

My invention will be best understood from the following description in connection with the accompanying drawings illustrating one embodiment thereof, and in which Fig. 1 is a vertical section through a boiler and its setting, constructed according to my invention and taken on the line I-I of Fig. 2; Fig. 2 is a partial plan view, and Fig. 3 is a section taken on the line 3-3 of Fig. 1.

Like reference characters indicate like parts in the several views.

In the illustrative embodiment of my invention, a plurality of steam and water drums ID are provided to each of which is connected a bank of inclined water tubes I I connected at one end to downtake headers I2 and at their other end to uptake headers I3. The downtake headers I2 are connected to the associated drum I0 by nipples I4, and the uptake headers I3 are similarly connected to the drum by nipples I5.

The front or uptake headers of the boiler are placed above the refractory front wall I! of the furnace chamber I8. Fuel burner nozzles I9 enter the chamber I 8 and are supported in the front furnace wall I'I. Ash outlets 2D communicate through the front wall I! with the lowest portion of the interior furnace chamber. Side walls 2| (one of which is illustrated in Fig. 2), a sloping floor 22, and a rear wall 23 complete the enclosure of the furnace chamber. The rear wall 23 is preferably joined to the floor 22 on a curve of relatively large radius, as illustrated at 23I A row of inclined slag screen tubes 24 crosses the upper portion of the furnace chamber I8 parallel with the tubes II and spaced therefrom.

The flame from the fuel nozzles I9 is deflected upwardly from the floor 22 and forwardly from the rear wall 23. A baffle 25 extends from the rear wall 23, along the slag screen tubes 24, and preferably supported thereon to deflect the hot gases forwardly in the furnace chamber and toward the front of the boiler tubes II. A baffle 26 extends upwardly from the forward edge of the baffle 25 to direct the first upward flow of hot gases across the bank of boiler tubes II. A refractory wall 27 and bafile 28 extend downwardly from the drums I0 across the major portion of the boiler tubes II between the bafile 25 and the downtake headers I2. The baffle 28 and wall 21 direct the gases in a downward pass over a soot pocket 29 formed between the bafiles 25 and 26 and the furnace setting.

The soot pocket 29 constitutes an open space below the boiler tubes I I where the gases make a turn and precipitate flue dust before making their last upward pass over the boiler tubes. An access opening 30 preferably communicates with the soot pocket. The flue gases pass upwardly from the soot pocket and passing between the nipples I4 enter the outlet flue 3| The floor 22 and rear wall 23 of the furnace chamber are relatively thin and are built upon and supported by water tubes 33 comprising part of a secondary circulation system. The floor and wall are preferably relatively flexible to accommodate themselves to changes, due to temperature changes. The secondary cooling circulation is independent of the main boiler circulation. A header 34 is connected to each of the boiler drums II] by tubes 35. This connection is made to the lowest part of each boiler drum near its cooler end, adjacent the nipples to the downtake headers. The header 34 extends outwardly of the furnace setting and is connected to a lower header box 36 by piping 31. The header box 36 is preferably in the plane of the floor tubes 33 which are connected thereto. The floor and wall tubes 33 discharge at their upper ends into a header 3B which, in turn, discharges into the tubes 24. A header 39 outside the front wall receives the steam and water from the tubes 24 and returns it to the boiler drums through connecting tubes 40 and 4|.

In the embodiment of my invention illustrated, two single boiler units each comprising two steam and water drums and the associated boiler tubes and headers are illustrated, mounted over a single furnace. Separate headers 38 and 39 are provided for each boiler unit as shown in Fig. 2. If desired, continuous headers may be used from side to side of the setting with partitions at their middle points in place of the separate headers.

The tubes 40 are connected to the upper side of the header 39 and to the steam space of one of the drums Ill. The tubes 4I enter the header 39 along its side and discharge into the steam space of the adjacent boiler drum III. In the secondary boiler circulation, water flows from the cooler parts of the drums II) to the lower header 36, thence through the cooling and supporting tubes 33 and the slag screen tubes 24 in series to the steam space of the boiler drums II]. This circulation provides an effective protection for the furnace walls against injury from excessive temperatures.

a special fioor construction which causes a rapid transfer of heat from the surface of the floor 22 to the cooling tubes which support it. The special floor is made of blocks 43 which rest upon and fit between the water tubes in the floor. The blocks 43 are preferably metallic and are mounted in intimate contact with the supporting tubes 33. Metal clamps 44 are bolted to the floor blocks and to each other. The clamps 44 intimately contact with the tubes and the blocks to' form a solid metallic floor gripping the tubes. The blocks 43 preferably have relatively small insets 45 of highly refractory material to protect the face of the metal from pitting and attrition by the action of the flame and hot slag particles. The insets 45, however, are each so small and so nearly completely surrounded by metal that they are kept comparatively cool as the heat is readily conducted from them through the metal to the water tubes 33.

A heat insulating casing 46 furnishes a suitable exterior or forms a finished surface to the exterior of the furnace wall. The floor and vertical wall may be supported by girders 4'! at one point only, as shown, or at any suitable intervals as may be needed. This support will permit movement of the floor and wall by flexure at the curve connecting them.

In operation, a rapid circulation is maintained through the tubes 33 and the slag screen tubes 24, due to the vigorous formation of steam in them. The presence of a large proportion of steam in the tubes containing the rising fluid causes a difference in the weight of the downcoming and rising columns of liquid and sustains a rapid and vigorous circulation. The water cooled floor of the furnace can thus be maintained at a temperature suitable for handling the slag which may be removed in the solid state in a disintegrated form, or which may be allowed to fuse on the floor of the furnace and afterwards be melted off by increasing the temperature of the furnace.

The soot pocket 29 is very conveniently disposed at a place in the system where difficulty would otherwise occur, due to accumulations of flue dust. It forms a simple and conveniently accessible means of trapping and holding flue It will be understood that the passageways 48 under the floor and between the castings 44 and the casing 46 may be occupied and cooled by circulating air, if desired, either to cool the floor or to heat air for any desired purpose. It will also be understood that my invention is not limited to the specific details or uses herein set forth, but changes therein may be made to suit the needs or particular circumstances.

I claim:

1. A boiler comprising a steam and water drum and a furnace having a cooling circulation comprising water tubes for the lining thereof and connected to said boiler, said circulation including an upper header and connections therefrom to the steam and water drum, a lower header exteriorly placed adjacent a lower wall of the furnace, continuous water tubes connected to said lower header and supporting said floor and a wall of the furnace, a third header to which said continuous tubes are connected, and slag screen tubes connecting said third header to said upper header.

2. In combination, a steam boiler comprising a bank of horizontally inclined water tubes, a set- Referring more particularly to Fig. 3, I show ting for said boiler comprising a furnace chamber located below said tubes, a Wall for said furnace chamber having a substantially vertical and a sloping portion, second water tubes located adjacent the said vertical and sloping portions, third water tubes extending below said bank of water tubes substantially parallel therewith and spaced therefrom and connected in series with said water tubes located adjacent the said wall, and means for creating a circulation through said second and third water tubes.

3. In combination, a steam boiler comprising a bank of horizontally inclined first water tubes, a setting for said boiler enclosing a furnace chamber located below said tubes, a furnace wall for said chamber comprising a sloping and a substantially vertical portion, second water tubes located in proximity to said wall for cooling the same, a cross header to which the upper ends of said second tubes are connected, third water tubes extending below said bank of water tubes substantially parallel therewith and connected to said cross header, and means for creating a circulation through said first water tubes and a.

circulation through said second and third water tubes.

4. In combination, a boiler comprising an upper drum, a bank of horizontally inclined tubes, end headers connected to said drum and to which the ends of the tubes of said bank are connected, a setting for said boiler enclosing a furnace chamber below said tubes, a furnace wall comprising a sloping portion and a substantially vertical portion, second water tubes located in proximity to said wall for cooling the same, third water tubes extending below said bank of water tubes substantially parallel therewith and connected in series with said second water tubes, and connections for creating a circulation through said second and third water tubes.

5. A furnace having walls, fuel burners for said furnace, a floor for said furnace, continuous water tubes extending beneath said floor and adjacent to one of said walls, said tubes being bent between the fioor and said wall, said floor and said wall being supported only at portions removed from said bent portions of the tubes, whereby said wall and said floor are flexibly supported at the bent portions of the tubes, and slag screen tubes traversing the upper portion of the furnace chamber, the tubes for said floor, wall and slag screen being connected in series.

6. In combination, a boiler comprising an upper drum, a bank of horizontally inclined tubes, end headers connected to said drum and to which the ends of the tubes of said bank are connected, a setting for said boiler enclosing a furnace chamber below said tubes, a furnace wall comprising a sloping portion and a substantially vertical portion, second water tubes located in proximity to said wall for cooling the same, the sloping portion of said wall comprising a floor laid upon the tubes, third water tubes extending below said bank of water tubes substantially parallel therewith and connected in series with said second water tubes, and connections for creating a circulation through said second and third water tubes.

7. In a furnace, a continuous wall closure for the bottom and one side thereof and comprising upper and lower fixed headers external to the furnace, a row of spaced water tubes connecting said headers and bent to form a sloping bottom and a substantially vertical side, members filling the spaces between said tubes, said wall being free I22. Ll'iiuliv HEATERS P. vAnOR ZE S.

to expand between said fixed headers, and means for causing water to flow through said tubes.

8. In a furnace, a continuous wall closure for the bottom and one side thereof and comprising upper and lower fixed headers external to the furnace located on one side and near the bottom, respectively, of said furnace, a row of spaced water tubes connecting said headers and bent to form a sloping bottom and a substantially vertical side, members filling the spaces between said tubes, said wall being free to expand between said fixed headers, means for causing water to flow through said tubes, and means for delivering a flame against said sloping bottom and said vertical side.

9. In a steam boiler and its furnace, a continuous wall closure for the bottom and one side thereof and comprising upper and lower fixed headers external to the furnace, a row of spaced water tubes connecting said headers and bent to form a sloping bottom and a substantially vertical side, members filling the spaces between said tubes, said wall being free to expand between said fixed headers, a boiler drum, and connections including slag screen tubes between the ends of said tubes and said boiler drum for completing the circulatory system.

Search lioom 10. In a furnace, a continuous wall for the bottom and one side thereof, said wall comprising a row of spaced water tubes bent to form a sloping bottom and a substantially vertical side, members filling the spaces between said tubes, said wall being free to expand between its ends, means to supply water to said tubes, and means for delivering a flame toward said sloping bottom and said vertical side.

11. In a furnace, wall cooling tubes forming an upright side wall and a horizontally inclined bot-. tom portion of the combustion chamber of the furnace, a header connected to the tubes at the lower end of the bottom portion, a header connected to the tubes at the top of the side wall, a support for said last named header enabling it to support a part of the weight of the combined side wall and bottom portion, refractory means carried by the tubes for completing furnace closures across the tubes, the side wall and bottom portion formed by the tubes and refractory extending at a substantial angle to each other and their adjacent parts movable outwardly of the combustion chamber when the temperature of the tubes is increased.

HOWARD J. KERR.

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