US2211127A - Furnace bottom - Google Patents

Description

F. KEYDEL FURNACE BOTTOM Aug. 13, 1940.l

Filed Aug. 5, 1938 3 Sheets-Sheet 1 f//s HrToR/v Ks Aug. 13, 1940. F KEYDEL 2,211,127

FURNACE BOTTOM Filed Aug. 5, 1938 3 Sheets-Sheet 2 f//s Arrbmver.

, wlmi@ Aug. 13, i940. F. KEYDEL;

FURNACE BOTTOM v Filed Aug. 5, 19.38

3 Sheets-Sheet 3 /f Illll II V/I l Patented Aug. 13, 1940 FURNACE no'r'roM Fritz Keydel, Berlin, Charlottenburg, Germany, assignor to Didier Werke Aktiengesellschaft, Berlin, Wilmersdorf, Germany, a corporation of Germany Application August 5, 1938, Serial No. 223,150 In Germany August 23, 1937 8 Claims.

My invention relates to the bottoms of blast furnaces and the like and its principal object is to prevent the bottom blocksfrom being floated out of place by the metal melted in the furnace. The invention consists principally in making the bottom with refractory blocks whose inner and outer faces are upwardly and inwardly inclined, with the inner face of each block overlapping the outer face of the block next inwardly thereof. It also consists in arranging the bottom blocks in parallel strings wherein the blocks of a string are keyed together and adapted to operate after the manner of an inverted flat arch, or wherein the blocks of one string overlap the blocks of the next adjacent string. It also conthereof. It also consists in making thebottom blocks of cuadrangular prismoidal form. It also consists in making the blocks in the form of sections of rings whose inner and outer faces are conical surfaces that taper upwardly and inwardly. It also consists in the parts and in the constructions and arrangements of parts hereinafter described and claimed. f

In the accompanying drawings which form a part of this specification and wherein like reference numerals refer to like parts wherever they occur,.

Fig. l is a central vertical section through a furnace bottom embodying my invention, the section being taken on the line I--I in Fig. 2;

Fig. 2 is a horizontal section on the line 2 2 in Fig. 1;

Fig. 3 is a horizontal section on the line 3-3 in Fig. 1;

Figs. 4 and 5 are fragmentary horizontal sections illustrating two modifled forms of the invention; and

Figs. 6 and '7 are a vertical section and a horil zontal section similar to Figs. land 2, illustrating another modication of thc invention.

The drawings illustrate the lower portions of blast furnaces, which comprise a middle portion, hereinafter called the bottom, and an annular peripheral portion, hereinafter called the wall, the bottom and the Wall being keyed together as hereinafter described.-

The bottom proper is made up of a series of layers each keyed to the wall or circumferential portion. The Wallis made of any suitable bricks refractory blocks and; comprises series of inverted skewbacks for thv f respective bottom layers. "I'he inner faces of `l the skewbacks incline (Cl. 2GB-25)' upwardly and inwardly.` The bottom blocks may be arranged in straight parallel strings, as in Figs. l to 5, in which case a separate skewback A is provided for each end of each string' and the skewbacks arranged in series of steps around the inside of the wall. The bottom blocks may be arranged in concentric annular series, as in Figs.V 6 and 7, in which case the inner surfaces of the skewbacks A are flush or continuous around the inside of the wall.

The bottom proper comprises a plurality of layers ofrefractory blocks. T he blocks of each layer are similar to the blocks of the other layers and are similarly arranged either in straight strings or annular series. When the blocks are arranged in straight strings, as in Figs. 1 to 5, the strings of the several layers are disposed helically with respect to one another, that is, the strings of blocks in veach layer are disposed at an angle (say forty-five degrees) further from a given diametral line than the strings of blocks y of the adjacent layers.

'I'he main bottom blocks B of the construction shown in Figs. 1 to 3 are of quadrangular prismoidal forms, that is, they have parallel quadrangular top and bottom bases I and 2 and two parallel quadrangular sides 3, the other two sides 4 and 5 being quadrangular but not parallel. `For purposes of description, the word width is used herein to` designate the dimension between equal parallel faces 3, the word length is used to designate the dimension between non-parallel faces 4 and 5, and the term depth is used to designate the distance between unequal parallel faces, the smaller of which is called the top face l and the larger of which is called the bottom face 2.

At two diametrica'lly opposite points of the wall, there are two inverted skewbacks A, whose inclined inner faces 6 overlap the outer faces 4 of the two endmost blocks of a straight string of blocks which string extends from one of said skewbacks to the other. The outer faces I-of said endmost blocks B are inclined to t or bear flatwise against said skewbacks A. The inner faces 5 of said endmost blocks incline' upwardly and inwardly in contact with the outer faces I of the blocks next to them in said string, and so on, the inner inclined face of each block overlapping and contacting with the'outer inclined face of the blocks `next inwardly thereof in the string. At the middle of a string there may be a single block B shaped with oppositely inclined faces like a keystone, or there may be two blocks B2 with their inner meeting surfacesl vertical.

Preferably the inclination of the inner face 5 of each block B is steeper than the inclination of its outer face 4.

The blocks of the diametral string above described are keyed together after the manner of an inverted flat arch. That is, the endmost blocks of the string are keyed under and against the skewbacks in the Wall and, in turn, key the blocks next to them in the string and so on to the middle of the string, where the midmost blocks B' and B2 act after the manner of the keystone of an inverted at arch. Thus all of the blocks of the diametral string are keyed together to resist upward pressure such as would develop in case heavy molten metal should get below the blocks, the blocks being lighter than the metal.

Alongside of the diametral string of blocks are a number of shorter strings of blocks B and B and B and B2 arranged chordally parallel with the diametral string above described. Aside from being shorter, these chordal strings are similar to the diametral string but preferably the blocks of each string are arranged to break joint with the blocks of the next adjacent strings. At the ends f the chordal strings, the skewbacks A in the wall are especially designed to conform to the slope of the outer face of the endmost bottom blocks of the string. The segmental space between. the outermost strings of blocks and the adjacent portions of the annular wall are filled with blocks B3 that are built into the wallI and project inwardly therefrom after the manner of corbels.

In the construction illustrated in Figs. 1 to 3, the blocks are arranged in straight strings keyed together and to the skewbacks in the wall so that each string acts after the manner of an inverted flat arch. In this construction, the strings are laid alongside of each other and serve to keep each other in position; but the failure of a block in one string has practically no effect in loosening the blocks in any other string. In the construction hereinbefore described, each block in a string overlaps the one next inwardly thereof n that string. However, it is practicable to make each string with blocks B4 having vertical meeting faces 1 and inclined sides so that the blocks of one string will overlap the blocks of the next adjacent string, as indicated at 23 in Fig. 4. Likewise, it is practicable, as shown in Fig. 5, to make each string with blocks B5 that are shaped so that the blocks of the same string will overlap each other, as at 45, in the manner shown in Figs. 1 to 3, and at the same time the blocks of each string will overlap, as at 23a, the blocks of the next adjacent string after the manner shown in Fig. 4.

In the construction hereinbefore described, the blocks are arranged in straight strings parallel with each other. In the construction illustrated in Figs. 6 and 7, the blocks B6 are arranged in concentric annular series with the blocks of each series having their inner faces inclined to overlap and bear flatwise, as at 45a, against the inclined outer faces of the blocks of the next series inwardly thereof. In this construction, the skewbacks A have a continuous conical surface 6a in the wall for the inclined outer surfaces of the blocks of the outermost series to t under; and in this construction, there is a single block B7 in the form of the frustum of a cone located at the center of the layer. The other blocks are in the form of sections of circular rings Whose inner and outer faces are conical surfaces that incline upwardly and inwardly. It ,is a merit of this annular arrangement that its skewback is much simpler and easier to build and that it requires only one size and shape of block for each annular series. This construction acts after the manner of an inverted vault or dome. That is, in resisting the otative effort of the molten metal. there is arch action in diametral lines throughout the circumference as distinguished from the arch action along parallel lines in the construction of Figs. 1 to 5.

It is noted that whether the blocks are arranged in chordal strings, as in Figs. 1 andl 2. or in annular series, as in Fig. 7, the inner and outer faces of the individual blocks incline upwardly and inwardly on the same hand or general direction with the inner face making a greater angle of inclination to the horizontal than the outer face of the individual block and with the angle of inclination to the horizontal of the -faces of each successive block increasing from the midmost block outwardly, whether the midmost block is midway of the chordal string or at the center of the annular series.

The construction above described has many advantages. It makes it practicable to use much larger blocks than has heretofore been feasible and thus minimizes the number and length of the block edges and joints. It also enables the blocks to be keyed together in independent strings that are impracticable with smaller blocks. This is true because the keying of smaller blocks requires an overhang that is relatively much larger than is required for keying larger blocks and because the smaller blocks require more joints and because there is a limit to the slope of the skewbacks in the wall. Besides, the small blocks require closer fitting and a given amount of spalling and erosion is much more destructive to a small block than to a large one and because the molten metal is very much more likely to get under and float out a small block than a large one.

What I claim is:

1. A furnace bottom having an annular wall and a bottom, said bottom comprising a layer of parallel strings of blocks with ends which incline upwardly toward the vertical plane through the middle of said strings whereby the inner end of each block overlaps the outer end of the block next inwardly thereof, said wall having faces that slope upwardly and inwardly above and conformably With the outer ends of the endmost blocks of the respective strings.

2. A furnace having an annular wall and a bottom, said bottom comprising a diametral string of blocks and shorter strings of blocks arranged chordally parallel with said diametral string on opposite sides thereof, the blocks of each string having their meeting ends inclined upwardly toward the vertical plane of said string, whereby the inner end of each block of a string overlaps the outer end of the block next inwardly thereof, the outermost blocks of each string being interlocked with said annular wall, said strings being disposed in horizontal layers and the strings of theprespective layers being disposed helically with respect to one another.

3. A furnace having an annular wall and n bottom, said bottom comprising a layer of par- 4. A furnace having an annular wall and a bottom, said bottom comprising a layer of refractory blocks disposed in parallel strings, said blocks having inclined sides and ends and being smaller at top than at bottom, whereby the upper portion of the inner face of each block of each string overlaps the outer face of the blocks next inwardly thereof in the same and adjacent strings, the endmost blocks of said strings being interlocked with said annular wall. v

5. A furnace having an annular wall and a.

bottom whose outer margin is mechanically interl locked with said wall, said bottom comprising refractory blocks disposed contiguously in parallel annular series, the side faces of the blocks being substantially radial and the inner and outer faces thereof inclining inwardly and upwardly whereby the inner face of each block of a series overlaps the outer face of the adjacent block of the next series inwardly.

6. A circular furnace hearth comprising a central refractory block in the form of a pyramidal frustum and refractory blocks disposed contigouter faces of the individual blocks being upwardly tapering conical surfaces substantially concentric with the axis of the hearth and their side faces being substantially radial with relation to said axis.

7.4 A furnace having an annular wall and a bottom, said bottom comprising la layer of refractory blocks arranged in strings, all of said blocks having an outer face inclining upwardly and inwardly and all but the midmost of said blocks having an inclined inner face disposed in overlapping relation to the inclined outer face of the block next inwardly thereof, and the outermost blocks being interlocked with said wall.

8. A furnace having an annular wall and a bottom whose outer margin ismechanically interlocked with said wall, said bottom being composed of refractory keying means and refractory blocks arranged in parallel series on opposite sides of said keying means, said blocks having the inner and outer faces inclining upwardly and inwardly and each block overlapping the block m KEYDEL.

' next inwardly thereof. uously in concentric circular series, the inner and

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