US1544870A - Furnace - Google Patents

Description

Jib-7,1925. Y 1,544,870

N. D. STEVENS FURNACE Filed July 31, 1920 2 Sheets-Sheet 1 STEVENS FURNACE Filed July 1920 2 Sheets-Sheet 2 I PatentedilhlyZlQZS. a X UNITED STATES PATENT OFFICE. I

na'rmmr. n. STEVENS, or wILxns-Bman, rnuxsnvmm, assronon *ro II. n. nnrmcx comm, or CHICAGO, more, a coaromm'rox or ILLINOIS.

ruanaca.

Application filed July 81, 1920. Serial No. 400,586.

To all whom it my'comem: J eluding elements of slightly modified con- Be it known that I, NATHANIEL D. struction; v p p I v S'rnvnNs, a citizen of the United States of Fig. 4 is a' side elevation of one of the America, residing at Wilkes-Barre, in the filler bricks shown in Fig. 3,

6 county of Luzerne and State of vPennsyl- Figs. 5 and 6 are side and end elevations, 60 vania, have invented certain new and userespectively, of one of the bricks of either ful Improvements in Furnaces, of which of the radial arches; L

the following is a specification. 7 and 8 aresimilar views of cer- My invention relates to furnaces, and artam bricks of the main arch shown in Figs. ticularly to the construction of the re- 1 and 2; and

box walls. Among the objects of my in- Fig. 9- is a section through portion of vention may be mentioned especially an imthe mam arch showing a further modified proved construction of the llning elements ,form of one of filler a of the fire box to secure greater durability, In its main. features the resent construcsecond, to provide dead air spaces between .tion corresponds to that s own in my cothe lining elements and the main body of. nding application Ser. No. 378,328, filed the walls, third, to'appl these-features of Q a 1, 1920,in that the bricks of the main improvements particular y' to arches of the arc are suspended' from transverse beams suspended type of construction. I 10 exposed to air cooling and" having at suit- 20 One of the more specific objects ofthe able intervals clamps 11 which en age the invention is the provision of a construction dove-tailed heads of tie bricks 12. etween, for arches or arch portions of convex ar-' adJa'cent rows of tie bricks extend supercuate form, such as may be employed in posed layers of filler bricks '13 and 14. In

positions .where it is des red to change the the constructmn shown in my previous ap- 25 course or direction of the refractory wall, plication, the .t1eZ'b1iCkS 12 extend the full 99 by virtue of which improved construction thickness of therarch, and are consequently such portions of the arch and their supexposed at their. inner ends to the heat'of porting members aresafeguard against dethe fire 'on the travehng grate 15. Inasterioration by the heat and combustion much as nnury to the exposed face of the,

'30 products within the combustionchamber, tie brick lessens the supportafiorded by and the component parts of the structure it to theintermediate filler bricks 14,1 have are rendered accessible and readily interfound 1t desirable to protect the tie bricks changeable for purposes of replacement or agalnst the dlrect heat and contact .of gases repair. in the fire box. 3f Other objects of the invention will be Asshown in F igs. 1, 2, 7 and8, empointed out hereinafter, indicated in the apploy for this purpose a tile 16, preferably efided claims or obvious to one skilled of some material capable of resisting very in the art from the present disclosure. high heat, such as carborundum, and secure 'In the accompanying drawings I'have this tile to'the filler brick 14 by means of 7 shown one form in which the 'invendove-tailed ribs 17 on the tile which fit into tion may be embodied, but it is to be corresponding channels 18 formed in the understood that the same is here presented fire-box face of filler brick 142. Where amfor illustrative purposes only, and that it terial" such as carborundunr is used as a facisnot to be construed in any fashion such mg or veneer tile, certain comphcations 45. as to limit the invention which I purport arlse from the fact that thlS material 1s to secure, short of its true and most coma good conductor of heat, and consequently rehensive scope in theart. In the drawwould transmit the tie brick substantially in'gs, which form a part of the specification, all the heat received by the facing tile, un-

Fig. 1 is a longitudinal section through less the brick were protected therefrom in 50 the fire box of a. furnace in which my insome way- An effective arrangement for vention is embodied in one form; protectin the .tie brick is a dead airspace Fig. 2 is a broken front levation 19 afior ed by making the ribs 17 on the thereof; 4 tile of suflic1ent height to holdv the tile Fig. 3 is a detail view in the nature of spaced from the fire-box face of the tie a section through a portion. of an arch inbrick a-slight distance. Inasmuch as the at the boiler end of the box in the direction of the flow of the products of combustion. The latter therefore exert a suction effect in a direction to draw a current of cooling air in through the channelsbel0 tween the carborundum tile 16 and the filler 'bricks 14, which serves to protect the latter as well as the tie brick 12 from heat injury. It is to be observed that the facing tile 16 and 23 are independently supported, each on individual tile. Accordingly, the facing tile do not interfere with the relative movement of the other tile incident to contraction and expansion, nor are they subjected to stresses incident to the expansion and contraction of the F other tile such as would tend to injure them.

The construction of the facing tile for the radial arches at the hopper end and boiler end of the fire box is illustrated in en- 2 larged view in 5 and 6. The same characteristics of construction are employed. The segmental bricks 20 have in like manner. undercut channels 21 in the fire-box faces thereof to receive the dove-tailed ribs 22 on the inner face of the tile 23. The latter are slightly wider than the tile in order that their margins may meet and thus afford a continuous protection at the inner surfaces of the radialarches.

In Figs. 3 and 4, I have shown a still further modification in that the filler brick 14* at the fire-box face of the main arch is made slightly thicker and is provided .with flanges 24 at its opposite margins of such extent that those of adjacent bricks meet on the downward extension of the midline of the tie brick 12, and thus protect the I fire-box face of the latter against heat injury. These flanges are preferably slightly spaced from the fire-box end of the tie brick 12, so as to afford a dead air space 25 between the flanges and the protected face of the tie brick.

I have also shown the filler brick slightly modified in the face thereof adjacent the outer brick 13 by depressing the outer face of the brick 14" to afford a channel 26, which thus gives a greater dead air space between the bricks 13 and 14 than provided in my prior construction.

In Fig. 9 the construction is substantially the same as that just described, with respect to Figs. 3 and 4, except that the filler brick 14 is not provided with a protective veneer tile 16, or with the channel 26. A construction of this type is satisfactory where the heat of the furnace does not run very high. In the illustrative embodiments shown and in any modifications thereof the'tile 12 and 20 may be regarded as suspension tile while the tile supported on them andproviding the fire resisting surface, such as the tile 14, 14", 16 and 23, may be termed the facing tile.

The advantage of the construction shown will be readily recognized when it is recalled that the fusion point of clay brick is approximately 3300 F.,'and that a safe working temperature should not exceed 3000 F. \Vhere the furnace is used to burn soft coal and powdered fuel, etc., the temperature in the fire chamber is often above the safe working point of the fire brick. The carborundum tile 16, however, will withstand a temperature as high as 4200-F., thus. rais ing the safe working temperature in the furnace approximately 1000. The construction employed for this purpose is simple and effective. The air circulation through the channels 19 is not sufficient to appreciably lessen the heat transmitted to the boiler, while on the other hand it is suflicient to protect the arch construction. These features are, of particular importance in the radial or convex portions of the arch, as in such parts where the course of the combustion gas is changed, there is the greatest tendency for the refractories to spall under the combined influence of the extreme heat and the errosive action of the products of combustion. My invention provides a con- I struction. for these portions of the arch which is effective to fully protect the metallic supporting members and tosafeguard the refractories, while permitting them the necessary freedom of relative movement to accommodate expansion and contraction and rendering the other parts acce$ible for replacement or repair.

Various modifications in detail of construction will occur to those dealing with the problem, which do not depart from what I claimas my invention.

What I claim is 1. In a furnace arch, a metal suspension beam wholly exposed for air cooling, spaced refractory tie blocks directly suspended therefrom, filler refractories engaged between said tie blocks and supported thereby, and means associated with said filler blocks for protecting the fire box ends of said tie'blocks against heat injury.

2. In a furnace arch, a metal suspension beam wholly exposed for air coolingfspaced refractory tie blocks directly suspended therefrom, filler refractories engaged between said tie blocks and supported thereby,

and means associated with said filler blocks &

therefrom, filler refractories engaged between said tie blocks and supported thereby, and means carried by said filler blocks for protecting the fire box ends of said tie blocks against heat injury.

4. In a furnace arch, a metal. suspension beam wholly, exposed for air cooling, spaced refractory tie blocks directly suspended thereflrom, filler refractories engaged between said tie blocks and supported thereby, and means carried by said filler blocks and air spaced from the fire box ends of the he blocksto protect the latter against heat inry. 5. In a furnace arch, an exposed suspension member, arch refractories hung therefrom, spaced layers of arch brick engaging said refractories and supported thereby, the faces of the bricks of one layer opposed the faces of the adjacent layer being recessed to afford an enlarged air space between the said layers.

6. A furnace arch construction comprising in combination metallic supporting members, wedge-shaped channelled suspension tile supported thereon'with their side faces in contact and their end faces in angularrelationship, and facing tile engaged in the channels of the 'sus nsion tile in covering relationship to their lower end and 00- operating to form a continuous refractory wall of arcuate contour.

7. In a furnace fire box, an arch compris ing fire brick, in combination with a tile veneer secured brick and spacedtherefrom to form a channel, said channel having an, unobstructed opening at one end in the direction of thetravel of the products of combustion from the firebox and at its other end to a cooling air intake.

. 8. In a fire-b0 chamber, a suspended arch forming the roof of the chamber, side walls having expansion chambers into which the ends of said roof enter,- together with a protective tile facing for said arch, the tiles entering said expansion chamber at opposite sides of the firebox, together with material in said expansion chambers serving to pack the latter againstair leakage.

' 9. In furnace arch construction, in combination, metallic supporting members, suspension tile individually suspended thereon, and surface tile supported on the suspension tile severally and cooperating to provide a continuous refractory surface for the furnace arch. I

10. In furnace arch construction, in combination, metallic supporting members,

Jwedge-shaped suspension tile supported suspension tile having end thereon, said to the fire-box face of said 7 said tile engaging faces in angular relationship, surface tile supported on the suspension tile and associated to tory surface, portions of said surface tile being spaced from the supporting tile to afford air conducting channels following the contour of the arch surface.

11. In furnace arch construction, in combination, metallic supporting members, wedge-shaped suspension tile supported thereon in angular relationship, and surface tile supported on the suspension tile severally, said surface tile being arranged to form a continuous refractory surface on the arch.

12. In furnace construction, in combination, a), plurality of arch sup-port'ng bars disposed in substantially horizontal relationship, a plurality of tile supporting memto bers associated with said arch supporting bars, said tile supporting members having tile engaging portions arranged in arcuate relationship, suspension tile suspended from said arch supporting bars and said tile supporting members, and refractories supported on said suspension tile' and covering their end faces, said refractories being associated to form a substantially horizontal arch port-ion supported by the arch bars and a contiguous convex arcuate arch portion supported by the tile supporting members.

13. In furnace arch construction, in combination, associated supporting members having ar'cuately arranged tile engaging portions, suspension tile supported thereon, and refractories suspended on the suspension tile and covering their end faces, said refractories being associated to form a convex arcuate portion of the furnace chamber.

14. In furnace arch construction, in combination, metallic supporting members, wedge-shaped mlspension tile supported thereon, and refractories suspended on the suspension tile with their outer surfaces associated to form- 'a convex heat resisting arch;

15. In furnace arch construction, in combination, a plurality of associated supporting members having tile engaging portions, wedge-shaped suspension tile retained by portions, said suspension tile beingprovlded with channels extending intermediate their converging sides, and refractories engaged in said channels and suspended from said suspension tile in association to form a convexheat resisting arch portion between the suspension tile and the. furnace chamber. r

In testimony whereof I have signed my name to this specification.

NATHANIEL D STEVENS.

form a continuous arcuate refrac-

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