US1964413A - Boiler furnace - Google Patents

Description

J. c. HOBBS BOILER FURNACE `lune 26, 1934.

Filed July 2, 1925 3 SheeLS-SheeI 1 e, HI 7 .77

IN VEN TOR.

June 26, 1934. .1. c. HOBBS vBOILER FURNACE Filed July 2, 1925 3 Sheets-Sheet 2 /Nl/ENTR aAqC ATTORNEYS June 26, 1934. J, c, HOBS BOILER FURNACE Filed July 2, 1925 3 sheets-sheet '5 A TTORNEYS' Patented June 26, 1934 UNITED sra-TES BOILER FURNACE James C. Hobbs, Panesville, Ohio` Application July 2, 1925, Serial No. 40,993

17 Claims.

My present invention relates to steam boiler furnaces, and particularly arrangements by which the walls of such furnaces' may be maintained and also particularly arrangements for connecting so-called slag screen tubes tothe steam boiler.

My invention will be best understood from the following description and the annexed drawings in which Fig. 1 is a side sectional elevation of an illustrative embodiment of my invention; Fig. 2 is an enlarged section on the line 2-2 of Fig. 1; Fig. 3 is a section on the line 3-3 of Fig. 2; Fig. 4 is a rear elevation of a part of the arrangement shown in Fig. 1; Figs. 5 and 6 are respectively a front elevation and a section on the line 6-6 0f Fig. 5, showing a connection shown in place in Fig. l, and Figs. 7 and 8 are respectively a longitudinal section `on the line 7-7 of Fig. 8 and a plan view, each on an enlarged scale, of a steam and water separator shown in place in Fig. 1.

Like reference characters indicate like parts throughout the drawings.

For the purpose of illustration, I have selected a water tube boiler of a well-known form placed over a furnace arranged for burning powdered fuel. The boiler, as illustrated, has a transverse steam and water drum 10, downtake headers 11, uptake headers 12 and water tubes 13. The furnace chamber 14, in the illustrative embodiment, is provided with an extension in front of the boiler. In the roof of such extension is a powdered fuel burner 15 arranged to direct the fuel downward. into the chamber 14. The front wall 16 is provided with air ducts and air supply open= ings into the furnace. The rear wall 17 is made up of one or more sections, each independently supported and arranged with slip joints between them.

Across the lower part of the chamber 14 is a plurality of slag screen tubes 18 connected at their front ends to headers 19, which, in turn, are connected through a pipe or pipes 2O and tubes 21 to the water spaces of the drum 10. The slag screen tubes are inclined upwardly so that their rear ends are higher than their front ends, these higher ends extending through the rear furnace wall.

In front of the rear wall 17 is a row of tubes 22 which extend practically parallel with the inner face of the wall 17, the lower ends of the tubes 22 being bent outwardly and extending through the rear wall, there being a tube 22 for each of the tubes 18.

Each tube 22 is connected to a tube 18 by a connector 23, shown on a large scale in Figs. 5

and 6, this connector being arranged with a removable closure 24 so that a cleaning tool may be inserted into the tube 18. If desired, the opening 24 may be made of such a size and in such a position, as shown, that a tool may also be entered in a tube 22. 'Ihe upper ends of the tubes 22 extend out through the rear wall 17 and are connected to inclined headers 25, the high ends of which are connected to vertical pipes 26 which, in turn, are provided with tubes 27 and 28, the former of which enter the steam and water drum 10 above the normal water level thereof and the lower row 28 entering at about the normal water level in the drum 10. x

With the arrangement so far described, the tubes 18 are iilled with water from the drum 10 through the tubes 21, the pipe 20 and the headers 19. The tubes 18 serve to cool the lower part of the furnace to cause the slag to be thrown out in hardened particles and these tubes absorb heat so that the water therein rises through the connections 23, the tubes 22, the headers 25, the pipes 26 and the tubes 27, 28. The circulation of the water through the tubes 22 serves to maintain the rear wall 17 by protecting it from the` to an upper header 33 outside of the furnace wall. At the ends of the headers 32, 33 are downcomers 34, 35 and the lower header 32 is connected by the pipe 36 to the pipe 20, whereby the lower header 32 is supplied with water from the drum' 10.

The upper header 33 is connected by a pipe 37 to a header 38 which, in turn, is connected by pipes 39 to the steam space of the drum 10. Between the pipe 37, the header 33 and the downcomer 35, a steam and water separator 40 may be provided, which may conveniently have the form shown best in Figs. 7 and 8, the interior of the separator being provided with helical spiral shelves 41 to separate the steam and water received from theheader 33 to permit the steam ,to ow upward to the pipe 37 and the water to be turned to the downcomer 35.

The straight vertical portions of the tubes 30 may be located in relation to the Wall 31 either in front of the wall or partly in the wall and, in the arrangement which I have used for` purposes of illustration, each of these straight portions is located in a slot 42 in the refractory wall. The wall 31 is held in place by a plurality of fixed vertical beams '43 between which extends a casing 44, a layer of heat-insulating material 45 being interposed betweenthe refractory absorbed by the tubes 30 and the water will flow upwardly therein to the header 33 and from thence through the downcomers 34, 35 to the lower header 32. In this way, a complete circulation of the water in the side wall cooling tubes is obtained independent of the boiler circulation, the' amount of water passing from the pipe 20 through pipe 36 to the lower header 32 being equal to the amount of steam generated in the tubes 30 plus any Water which may pass through the pipe 37 to the steam spaces of the boiler.

If desired, theslots 42 may be permitted to be filled with slag and such tubes maintain the wall not only by keeping its temperature low enough to avoid the destruction of the wall, but' also will prevent the bulging of the wall inwardly, since such tubes act as a kind of holding members, the outward motion of the wall being prevented by the beams 43.

If desired, the upper header 33 may be inclined somewhat so that the pipe 37 can be connected directly to it to receive the steam which would then rise to the higher end of the header. While preferably I provide the downcomers 34, 35 at the ends of headers 32 and 33, it will be understood that such downcomers may be located in any desired position, so long as they are subjected to less heat than are the tubes 30. As has been said, the lheader and downcomer arrangement provides a device by which there is a local circulation in the side wall cooling tubes, so that small piping between the tubes and the boiler proper need be provided instead of the large piping which is necessary if the side wall cooling tubes formed part of a direct circulatory connection between the water space and the steam space of the boiler. It will also be understood that, if desired, the connection from the header 38 through tubes 39 to the drum 10 may be beneath the -water level sothat the pipe 37 will be lled with water at all times. The possibility of forming steam pockets in the pipe 37 and its connections is avoided by causing it to carry steam only.

It will be understood that the arrangement which I have shown is illustrative only and that the embodiment of my invention may be widely varied. It will also be understood that some of the features may be used independently of others.

I claim:

1. In a steam boiler and its furnace, a bank of vertically disposed furnace wall cooling tubes subjected to the heat of the furnace, an upper and a lower horizontal header connected to the ends of said tubes, downcomer pipes connecting said headers, a connection between the lower header and the boiler water space and a connection between the upper header and the boiler steam space, and a steam and water separator between said upper header and said last named connection.

2. In a steam boiler and its' furnace, a bank of vertically disposed furnace wall cooling tubes subjected to the heat of the furnace, an upper and a lower 4horizontal header connected to the ends of said tubes, downcomer connections outside the wall and connecting said headers, a connection between the lower header and the boiler water space and a connection between the upper header and the boiler steam space.

3. In a steam boiler andits furnace, a bank of furnace lwall cooling tubes subjected .to the heat of the furnace, headers outside the furnace wall and connected to the ends of said tubes, a pipe `connection between said headers outside `the furnace wall, a water connection between one of said headers and the water space of said boiler, a steam connection from the other header to the steam space of said boiler, and a steam and water separator between said upperheader and said steam connection.

4. In a steam boiler and its furnace, a plurality of slag screen tubes extending across the furnace, a plurality of vertically disposed wall cooling tubes, connections between the upper ends of said cooling tubes and the boiler spaces, connections between one end of each of said slag screen tubes and the boiler spaces, the lower end of each of said wall cooling tubes Abeing bent outward, and angle fittings, each connecting the other end `of one of said slag screen tubes with the bent lower endl of one of said wall cooling tubes. -f

5. In a steam boiler and its furnace, a plurality of slag screen tubes Aextending across the furnace, a plurality of vertically disposed wall cooling tubes inside the furnace wall, with their lower ends bent outwardly and extending through the furnace wall, connections between the upper ends of said cooling tubes and the boiler spaces, connections between one end of each of said slag screen tubes and the boiler spaces, and angle fittings outside the furnace wall, each connecting the other end of one of said slag screen tubes with the lower end of one of said wall cooling tubes. A

6. In a steam boiler and its furnace, a bank of vertically disposed furnace wall cooling tubes, an upper and a lower horizontal header connected to the ends of said tubes, downcomer pipes connecting said headers, a connection between the lower header and the water spaces of the boiler, a connection between the upper header and the. steam space of the boiler, and a steam and water separator, between said upper header and said last named connection.

7. In a steam boiler and its furnace, a bank of vertically disposed furnace wall cooling tubes, an upper and a lower horizontal header connected to the ends of said tubes, downcomer pipes connecting said headers, a connection between the lower header and the water spaces of the boiler, and a connection between the upper header and the steam space of the boiler, said last-named connection having a steam and water separator therein adjacent the upper header.

8. In a steam boiler and its furnace, a bank of vertically disposed furnace wall cooling tubes subjected to the heat of the furnace, an upper and a lower horizontal header connected to the Vends of said tubes and outside the furnace wall, a

vertically disposed downcomer connection at each end of the upper header and connected to the lower header, a connection between the lower header and the water spaces of the boiler, a steam and Water separator between the upper end of one of said downcomer pipes and the upper header, and `a connection between said separator and the steam spaces of the boiler.

9. In a boiler, a furnace, an upper header and a lower header, a connection from said boiler to said lower header, a row of furnace wall tubes connecting said upper and lower headers and delivering a mixture of steam and water to said upper header, means to cause the water delivered to said upper header to be divided into two parts, said means compri/sing a recirculator be- `tween said headers to,return a portion of said water to said lower header, and also comprising a connection from said upper header to a higher point in said boiler than the place where said lower header is connected to the boiler for returning said steam and the remainder of said water to said boiler, the point of said connection to the boiler being above the aforesaid upper header a distance at least half the distance between said headers.

10. In a boiler, a furnace, an upper header and a lower header, a connection from said boiler to said lower header, a row of furnace wall-tubes connecting said upper and lower headers and delivering a mixture of steam and water to said upper header, means to cause the water delivered to said upper header to be divided into parts, said means comprising a recirculator between said headers to return a portion of said water to said lower header, and also comprising a connection from said upper header to a higher point in said boiler than the place where said lower header is connected to the boiler for returning said steam and the remainder of said water to said boiler, said connection from the upper header to the boiler having a cross-sectional area less than that of said row of furnace wall tubes.

l1. In a boiler, a furnace, upper and lower headers, a connection from said boiler to said lower header, a row of furnace wall tubes connecting said upper and lower headers and dclivering a mixture of steam and water to said upper header, means to cause the water delivered to said upper header to be divided into two parts, said means comprising a recirculator between said headers toreturn a portion of said water to said lower header, and also comprising ail a connection from said upper header to a higher point in said boiler than the place where said lower header is connected to the boiler for returning said steam and the remainder of said water to said boiler, said connection from the upper header to the boiler having a cross sectional area less than that of said recirculator.

12. In a boiler, a furnace, an upperand lower header, a row of furnace wall tubes connecting said upper and lower headers and delivering a mixture of steam and water to said upper header,

a connection from said boiler to said furnace wall tube arrangement, means to cause the water delivered to said upper header to be divided into two parts, said means comprising a recirculator between said headers to return a portion of said water to said lower header, and also comprising a connection from said upper header to a higher point in said boiler than the place where said lower header is connected to the boiler for returning said steam and the remainder of said water to said boiler, the point of said connection to the boiler being above the aforesaid upper header a distance at least half the distance between said headers.

13. In combination, a vapor generator including a vapor and liquid separator having a maintween the compartments returning the remainder of the liquid to the lower compartment, and a supply connection constantly replacing with 1iq`- uid any liquid and vapor removed from the upper compartment.

14. In combination, a vapor generator including a vapor and liquid separator having a maintained liquid level, furnace walls enclosing a combustion chamber heating said generator, means for firing said combustion chamber with finely divided fuel, furnace wall protecting tubes spaced along at least one of the walls and subjected to radiant heat for a major portion of their length, compartments, one connecting the upper adjacent ends of said tubes and the other the lower adjacent ends, both submerged beneath the liquid level of the separator, a connection from the upper compartment to the generator to take away part of the liquid caused to move upwardly of the tubes by heat of combustion, a connection between the compartments returning the remainder of the liquid to the lower compartment, and a supply connection constantly replacing with liquid any liquid and vapor removed from the upper compartment.

15. In combination, avapor generator including a vapor and liquid separator having a maintained liquid level, furnace walls enclosing` a combustion chamber heating said generator, means for ring said combustion chamber with nely divided fuel, furnace wall protecting tubes spaced along at least one of the walls and subjected to the furnace heat in the flame zone, compartments, one connecting the upper adjacent ends of said tubes and the otherthe lower adjacent ends, both submerged beneath the liquid level of the separater, a connection from the upper compartment to the generator to take away part of the liquid caused to move upwardly of the tubes by heat of combustion, a connection between the compart- `ments returning the remainder of the liquid to the lower compartment, and a supply connection constantly replacing with liquid any liquid and vapor removed from the upper compartment.

16. In a boiler furnace, a bank of vertically disposed furnace wall cooling tubes subjected to the heat of the furnace, an upper and a lower horizontal header to which the ends of said tubes are connected, a connection between said headers outside of said furnace, a connection between the lowerheader and the boiler and a connection between the upper header and a higher point of the boiler, said last named connection being no larger in effective area than that of said connection between the lower header and the boiler.

1'7. In a steam boiler and its setting, a furnace wall, a steam and water drum, a circulatory system for said boiler including tubes and water chambers connected to said drum, upper and lower chambers located below said first-named chambers, tubes connecting said last-named water chambers and located adjacent to and cooling said furnace wall, other tubes connecting said last-named water chambers and located at the rear of said wall whereby a circulation may take place through the tubes connecting said lastnamed water chambers, a connection between said upper chamber and said steam and Water drum, and connections between said circulatory system and said lower water chamber.

JAMES C. HOBBS.

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