US2846963A

US2846963A - Reinforcing insert for furnace block

Info

Publication number: US2846963A
Application number: US628054A
Authority: US
Inventors: Donald W Mason; William H Myers
Original assignee: Harbison Walker Refractories Co
Current assignee: Harbison Walker Refractories Co
Priority date: 1956-12-13
Filing date: 1956-12-13
Publication date: 1958-08-12
Anticipated expiration: 1975-08-12
Also published as: DE1087740B; GB825252A

Description

, D. vw.`MAso`N Erm. REINFoRcIuG' INSERT Fon FURNACE BLOCKl Aug. 12, 195s Filed Dec'. is, 195e Pig-2 INVENTORJ MnSoN @ausw w.

@Batman C ,vl/es 2,846,963 'Patented AU- 12v 1958 REINFoRCrNG INSERT FOR FURNACE BLOCK Donald W. Mason and William H. Myers, Glen Burnie, Md., assignors to Harbison-Walker Refractor-ies Co., Pittsburgh, Pa., a corporation of Pennsylvania Application December 13, 1956, Serial No. 628,054

6 Claims. (Cl. 'lill- 99) This invention relates to basic refractory bricks that are used in industrial furnaces, and more particularly to such bricks that are suspended from their upper ends to form furnace roofs and arches, and to bricks suspended to form furnace walls.

It is well known that basic refractory bricks can be reinforced by molding into them metal plates, which will oxidize and bond themselves to the refractory when the bricks are heated. The plates also increase the thermal conductivity of the refractory, thereby protecting it against overheating.

It is among the objects of 'this invention to provide a metal reinforcement for such a brick,. which is easy to mold into the brick, which strongly reinforces the brick, which forms a metal liner or reinforcement for the hanger recess in the brick, and which permits a metal case to be rmly anchored on the brick.

In accordance with this invention, where the bricks are used in furnace roofs an upright metal plate extends vertically through an upright brick at one side of the hangerreceiving recess that is formed in one side of the brick near its upper end. Integral with the plate is a metal strip which extends along a vertical edge of the plate at an angle to the plate. The strip is only long enough to cover part or all of the portion of the recessed side of the brick below the recess. The upper end of the strip has an extensionbent in across the plate and then curved upward and outward again to form a tongue-like lining for the hanger recess. For best results, there are two metal plates in the brick which are integrally connected by the outside metal strip so that an insert is formed resembling an upright channel. It is preferred to cut away or notch the upper corners of the plates above the vertical metal strip. 'Ihe metal strip may be provided with one or more openings, which can receive projections punched into them from a metal case mounted on the brick.

The invention is illustrated in the accompanying drawings, in which Fig. 1 is a view of the recessed side of the reinforced bIlCk; f l

Figs. 2 and 3 are vertical sectionstaken on the lines II-II and Ill-Ill, respectively, of Fig. 1;

Fig. 4 is a plan view;

Fig. 5 is a horizontal section taken on the line V-V of Fig. l; and

Fig. 6 is a perspective view showing the block mounted in a case.

Referring to the drawings, the basic refractory brick 1 may be made of dead burned magnesite, chrome ore, olivine or other basic oxides or blends thereof, as is well known. Alumina in calcined, fused or sintered form is sometimes an ingredient of such blends. In the operating position of a furnace roof brick it is vertical or upright, so everything will be described in that position. Molded into one side of the brick near its upright end is a recess 2 for receiving half of the usual hanger (not shown), by which a pair of such bricks are suspended. The recess lmay taper toward its inner end to some extent, and has anupwardlyaring outer end. However, the invention about to bedescribed is applicable to basic bricks of a great variety of designs, all containing indentations of some kind for receiving supporting hangers. On the other hand, the invention is concerned only with chemically bonded unred basic bricks or those which before use are not heated to a temperature sufficient to destroy the reinforcing metal elements.

For reinforcing the brick, a metal insert is molded intol the refractory atthe time the brick is formed. Preferably, the insert is formed from a single sheet of metal which is bent int-o a channel shape having two side plates 3 connected along one vertical edge of each by a vertical web strip 4. Preferably,` the main bodies of the side plates are substantially parallel. The channel is wide enough to permit the two plates to straddle the lower portion of recess 2, but it is desirable to bend their upper portionsl awayfrom eachother to space them farther from the re-l cess. As the upper part of the recess shown is considerably wider than its lower part, it is desirable to cut away the adjacent upper corners of the plates to form large notches 6 (Fig. 2) to avoid having thin sections of refractory between the plates and the recess. The notches extend fromvthe upper ends of the plates down beside the lower part of the recess. ln some cases the channel may be made wide enough to avoid having to notch its side plates. The plates may be provided with openings 7, through which the brick material will extend to help key the plates into the brick.

The vertical web strip 4 of the insert is not fully ernbedded in the brick, but has its outer surface exposed and flush with the brick at the opposite edges of the strip. The metal strip covers the brick only between the bottom of the brick and the bottom of the hanger recess, which also is generally the lower end of the notches in the'side plates. The upper end of thestrip has an integral extension 8 that is bent back into the recess and up around its inner end and then forward again, as shown in Fig. 3. This tongue-like extension may conform to the upper and lower walls of the recess and to its inner end to form a metal lining for the recess. lf desired, the upper part of the extension tongue can be inclined slightly and completely embedded in the brick material where it will serve to reinforce-the upper part of the brick between the side plates but will not form an exposed lining for the upper wall of the recess.

When this brick is heated in service, the heat applied.

to its bottom or hot end will cause the metal insert to oxidize and bond itself to the adjoining brick material so that the brick will be strongly reinforced. In addition, the metal lining or reinforcement for the hanger recess increases the' strength and life of the brick at that point so as to prevent the structuralfailures which are now so common.` Since the recess lining is joined to the metal channeLthe pull on the lining due to the weight of the suspended block is distributed by the channel throughout the brick. Thereinforcement described herein lends itself very well to instances Where the block is mounted in a sheet metal case. The two holes 10 shown in the web strip of the insert are used for positoning the insert on the magnetized upper die of the mold in which the brick is shaped. They receive thin circular bosses projecting from the die. The same holes can be used for anchoring the -case on the block. As shown in Fig. 6, a two-part case 11 is spot welded together around the block, and one side of the case is punched into the holes in the web strip of the insert. The case metal l2 protruding into those holes assures that the block cannot slide out of the case, as it might otherwise do if it were not applied to the block tightly enough in the beginning. The type of case and manner of application are not material to this invention.

lt is even possible to press our reinforcing insert into the refractory material while forming the brick and simultaneously pressing the material into one or more metal encasing elements.

. By having the side plates joined to the web strip, the problem of supporting the plates while they are being moved edgewise down into the refractory material in the mold is solved. The web strip supports the plates and is held a-t against the magnetized mold in the proper position by the bosses just mentioned.

All brick with hanger recesses suffer some loss of strength at the recesses due to the diminished cross-sectional area of the refractory in that Zone, and therefore fracture of the brick near the recessed end is a common problem. A major contribution of our invention is the provision of a metallic reinforcement for the weakest area of the brick. Furthermore, another problem encountered where basic bricks have included metal elements for connection to hangers has been that the oxidation, which is so desirable at the hot end of the brick, also occurs to an undesirable extent at the opposite end and endangers the hanger engaging element, which loses strength as it is oxidized. Our tongue-like metal reinforcement for the hanger recess has a much longer life because at least one of its major faces is completely covered and protected by refractory material.

For convenience of terminology, the claims define the invention as if the brick were upright, but it is to be understood that the invention is not limited to an upright brick, as the position of the brick does not affect the inventive concept.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise `than as speciically illustrated and described.

We claim:

l. A reinforcing insert adapted to be molded into an upright brick that has a hanger-receiving recess in one side near its upper end, the insert comprising an upright metal plate adapted to extend vertically through the brick at one side `of its recess, and a vertical metal strip extending along a ver-tical edge of the plate at an angle to the plate and integral therewith, said vertical strip being only long enough to cover a portion of the recessed side of the brick below the recess, and the upper end of the strip having an extension bent in across the plate and ythen curving upward and outward to form a tongue-like lining for the top and bottom of said hanger recess.

2. A reinforcing insert adapted to be molded into an upright brick that has a hanger-receiving recess in one side near its upper end, the insert comprising an upright metal plate adapted to extend in the brick substantially the full height of the brick at one side of its recess and having a large notch in an upper corner, and a vertical metal strip extending along the vertical edge of the plate below said notch at an angle to the plate and integral therewith, said vertical strip being adapted to cover a portion of the recessed side of the brick below the recess,

4 and the upper end of the strip having an extension bent in across the plate and then curving upward and out to form a tongue-like lining f-or the top and bottom of said hanger recess.

3. A reinforcing insert adapted to be molded into an upright brick that has ahanger-receiving recess in one side near its upper end, the insert comprising a vertical sheet metal channel having spaced side plates joined along a vertical edge of each by a web strip, the channel being adapted to have its side plates embedded in the brick at opposite of the recess and to have said web strip engage the outside of the brick only below the recess, and the upper end of the web strip having an extension bent inwardly between said plates and then curving upward and outward to form a tongue-like lining for the top and bottom of said hanger recess.

4. A furnace block comprising an upright refractory brick that has a hanger-receiving recess in one side near its upper end, a vertical sheet metal channel having spaced side plates joined along a vertical edge of each by a web strip, said plates being embedded in the brick at opposite sides of its recess and extending substantially the full height of the brick, said web strip covering the outside of the brick below the recess and having an extension bent inwardly between said plates and then curving upward and outward to form a tongue-like lining for said hanger recess, and the upper corners of the plates beside said recess being provided with large notches.

5. A furnace block comprising an upright refractory brick that has a hanger-receiving recess in one side near its upper end, a vertical sheet metal channel having spaced side plates joined along a vertical edge of each by a web strip, said plates being embedded in the brick at opposite sides of its recess, said web strip covering the outside of the brick below the recess and having an extension bent inwardly between said plates and then curving upward and outward to form a tongue-like lining for said hanger recess, said web strip being provided with an opening, and a metal case engaging the sides of the brick and having a projection extending into said web strip opening.

6. A furnace block comprising an upright refractory brick that has a hanger-receiving recess in one side near its upper end, an upright metal plate extending vertically through the brick at one side of its recess, and a vertical metal strip extending along a vertical edge of the plate at an angle to the plate and integral therewith, said vertical strip being `only long enough to cover a portion of the recessed side of the brick below the recess, the upper end of the strip having an extension bent in across the` plate and then curving upward and outward to form a tongue-like lining for said hanger recess, said strip being provided with an opening, and a metal case engaging the sides of the brick and having a projection extending into said strip opening.

References Cited in the file of this patent UNITED STATES PATENTS 2,577,428 Mohr Dec. 4, 1951 2,652,793 Heuer et al Sept. 22, 1953 2,725,833 Reintjes Dec. 6, 1955