US2091224A

US2091224A - Furnace construction

Info

Publication number: US2091224A
Application number: US83024A
Authority: US
Inventors: James E Brinckerhoff; James D Mccullough; Roscoe E Swift
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1936-06-02
Filing date: 1936-06-02
Publication date: 1937-08-24
Anticipated expiration: 1954-08-24

Description

Aug- 24, 1937. J. E. BRINCKERHOFF Er AL 2,091,224

FURNACE CONSTRUCTION Filed June 2, 1936 2 Sheets-Sheet 1 J. E. BRINCKERHOFF r AL 2,091,224

FURNACE CONSTRUCTIN Aug. 24, 1937.

Filed June 2, 1956 2 Sheets-Sheet 2 Patented ug. 24, 1937 UNITED STATES oF'FicE FURNACE CONSTRUGTIUN Application .lune 2, 1936, Serial No. 83,024

9 Claims.

This invention relates to furnaces, and it is exemplied herein as involving improvements in arches used as covers for soaking pits.

It is an object of the invention to provide a soaking pit cover with low density ceramic refractory elements of high heat insulating capacity so that heat'losses will be minimized.

It is also an. object of the invention to provide a portable arch or soaking pit cover which Will have a refractory lining capable of withstanding the high temperature gases and flames which are necessary in the operation of a soaking pit, and at the same time having such a low weight per unit of furnace face that soaking pits of wide cross section can be advantageously closed by a unitary structure.

In the use of soaking pits the portable arches which constitute their covers are arranged to be shiftable to and from a position over the top of the furnace pit. For this purpose, some arches are mounted on motor driven carriages operating along tracks which have spaced depressions in which the wheels of the carriage' naturally tend to become seated when the carriages are moved toward their operative positions over the furnaces, or pits. When the wheels of a carriage drop into these depressions the marginal parts of the cover contact with sand or similar granular material which has been spread around the top of the soaking pit to form a ame or gas seal. These parts are thus subject to repeated impacts and considerable abrasion during the normal use of the soaking pit. Not only must they have sufficient durability or mechanical strength to withstand such repeated impacts and abrasions, but they must also be strong enough to support the weight of the arch in the event that foreign bodies or excessive amounts of sand occur around the tops of the soaking pits.

If the entire arch was faced with refractories of high enough density to adequately withstand the above indicated punishment, the weight of the arch would be excessive. Furthermore, in connection with soaking pits of large cross section, the weight of the steelwork required to support such high density refractories would be excessive. By way of an example of such high density refractories as are referred to herein, ordinary rebrick weighing about 130 lb. per cubic foot are considered to be of high density. The low density refractories are considered to be those which have a density of i'rom 1/3 to 1/2 lem by providing a soaking pit cover, the major portion of which presents a furnace face formed by low density refractories of high heat resisting and high insulating capacities. With such a construction the arch can cover a wide expanse at the top of the soaking pit without requiring an excessively` heavy steel supporting framework. Furthermore, heat losses are minimized and better working conditions are promoted by reason of the insulating capacity of the low density refractories. The invention contemplates that the main furnace face portion of the arch shall be encircled by refractories of -higher density which can successfully withstand the severe condition to be met in the operation of soaking pits. Their resistance to abrasion is high and they are not easily broken by blows which soaking pit covers may receive during the operation of the cranes which remove heavy ingots from the soaking pit or position them therein. Such 20 actions occur due to the necessity of maintaining the ingots at a high temperature, and the desire on the part of the operator to move the ingots quickly in order that the ingots remaining in the soaking pit shall not have their temperatures excessively-lowered by the temporary removal of the cover.

Other objects of the invention will appear as the accompanying description proceeds.

The invention will be described with reference to the attached drawings, in which:

Fig. 1 is a view in the nature of a vertical section indicating the carriage wheels for supporting the arch, and showing the relationships of the refractories to the supporting framework.

Fig. 2 is a view in the nature of a vertical section taken along a plane at right angles to the plane of Fig. 1, and indicated by the line 2--2 of Cil ' Fig. l.

Fig. 3 is a partial plan broken away at one corner to show the relationships of the marginal refractories to the inner elements.

Fig. 4 is a detailed View in the nature of a perspective showing the manner in which the inner refractories are suspended from the supporting steelwork.

Fig. 5 is a detail view in the nature of a perspective indicating the manner in which some of the marginal refractories are secured to the steelwork.

Fig. 6 is a detail view in the nature of a horizontal section showing a modification by which some of the marginal refractories are supported from the steelwork. This view is taken on the line 6 6 of Fig. 7.

Fig. '7 is a detail view in the nature of a vertical section taken on the line l-l of Fig. 6, and further showing how the marginal refractories of Fig. 6 are supported.

In the drawings, Fig. 2 shows the top of a soaking pit lb having side walls l2 and M- over the tops of which sand is spread to form a gas and flame seal as shown at l@ and lil. In some instances this sand also aiords a support for the 10 cover.

The soaking pit cover indicated generally by the numeral 2t contacts with the sand seals as indicated, and may be portably supported (in its inoperative position) by a superposed carriage which includes the axle 22 and the wheels lill and 2li. The latter are arranged to run upon tracks Sill and liti having the depressions 342 and liti so arranged that the wheels drop into them as the cover approaches its operative position.

The cover, as an entirety, may be supported from the carriage in any suitable manner. The former involves a steel frame consisting of the beams lli] and l2 connected by the transverse channels ifi and i6 and the I beams '58 and Llil. Brick supporting angles Sil and 52 extend across the arch, with their ends supported upon angles 5l?. and 56 which are rigidly secured to the beams ft2 and llt).

The angles 5U and 52 support the low density refractories 58 in the manner indicated in Fig. 4

of the drawings. As shown, these refractories are apertured to receive the horizontal suspension rods 60 and they are recessed at their upper ends to receive the eyeebolts 52 which extend through openings in the horizontal flanges of the angles Ell and 52. These eye-bolts may be maintained in their operative position by cotter pins t5 extending through openings in their stems, as

shown. As indicated in Fig. 3 of the drawings, i0 the rods @El are rather short. That is, they do not extend all the way across the soaking pit cover, and are so arranged that a small number of the refractories 58 may be removed as a unit for the purposes of repair and replacement,

Fig. 2 shows the high density refractories Gil as extending below the furnace face formed by the inner refractories and abutting at their tops against the horizontal portions of the angles 513 and 56. They are rigidly secured to the beams 42 and i0 by bolts 6G which hold them tightly in position with compressible insulating material 6B interposed with reference to the refractories 64 and the beams.

Instead of securing the high density refractories 6ft as indicated in Fig. 2, they may be secured in the manner indicated in Figs. 6 and 7. As here shown, T members 'i are rigidly secured to the inner faces of the beams t2 and 40 and the high density refractories 12 are formed with lateral recesses and slots so that they may be positioned over the T members T0 and thereafter dropped into their operative positions indicated in Fig. 7.

Figs. 2, 5, and 7 indicate other marginal refractories M secured to the horizontal flanges of the

beams

42 and 40 so as to protect the latter against the flames from the soaking pit. These refractories are secured to the lower horizontal flanges of the beams in the manner indicated in Fig. 5. As here indicated, refractories 14 are apertured to receive horizontal rods 'i6 secured to the flanges 18 by eye-bolts 80 which are positioned within recesses in the refractories, as shown.

Figs. 1 and 3 show the high density refractories which are arranged along the remaining margins ancrage While the invention has been described with reference to the particular modications shown in the drawings, it is to be appreciated that it is not necessarily limited to the particular combina tions shown therein. It is, rather, oi a scope,

commensurate with the scope of the subjoined claims.

What is claimed is:

1. In a soaking pit cover, a portably mounted metallic framework, refractories of low density and high heat resistance forming the main heat resisting portion of the cover, a band of high density refractory elements encircling said portion and adapted to be contacted by sealing matcrial deposited around the top of the soaking pit.

and means for detachably securing all of said refractories to said framework.

2. In combination with a furnace having an upwardly presented charging port of large arca. a readily removable arch normally closing said port and comprising, relatively low density refractory elements forming the main heat resisting portion of the arch spanning the port, rows of high density refractory elements of high load sustaining capacity positioned at the margins of the arch, steel-Work spanning the port, and meansI for suspending the refractory elements from the steel-work, said high density elements having their lower surfaces extending below the flame face of the main portion of the arch.

3. In combination with a furnace having an upwardly presented charging port of large area, a readily removable arch normally closing said port and comprising, relatively low density refractory elements forming the refractory body of the main portion of the arch spanning the port, rows of high density refractory elements of higher load sustaining capacity positioned at the margins of the arch, steel-work spanning the port, and suspending means including upper bars bridging the steel-work and lower supports interengaged with the refractory elements.

4. In combination with a furnace having an upwardly presented charging port of large area, a readily removable arch normally closing said port and comprising, relatively low density refractory elements forming the main portion of the arch spanning the port, rows of high density refractory elements of high load sustaining capacity positioned at the margins of the arch and arranged to take at least a part of the load of the arch, steel-Work spanning the port, and means for suspending the refractory elements from the steel-work, said steel-work including members which bear directly against the high density refractory elements.

5. In combination with a furnace having an upwardly presented charging port of large area, a readily removable arch normally closing said port and comprising, relatively low density refractory elements forming the main portion of the arch spanning the port, rows of high density refractory elements of high load sustaining capacity positioned at the margins of the arch, and means for suspending the refractory elements from the steel-work, there being two rows of high density refractory elements at opposite margins of the arch, with one row of said elements of each side having their wider faces presented toward the Walls forming the furnace opening to permit the port to be closed with a Wide sand seal.

6. In combination with a'furnace having an upwardly presented charging port of large area, a readily removable arch normally closing said port andcomprising, relatively low density refractory elements forming the refractory body of the main portion of the arch spanning the port, rows of high density refractory elements of high load sustaining capacity positioned at the margins of the arch and arranged so that they may take at least a part of the load of the arch, steel-Work spanning the port, and means for suspending the refractory elements from the steel-work, said high density refractory elements having interengaging portions.

7.*In combination with a furnace having an upwardly presented charging port of large area, a, readily removable arch normally closing said port and comprising, relatively low density refractory elements forming the main portion of the arch spanning the port, rows of high density re-A fractory elements of high load sustaining capacity positioned at the margins of the arch and ar,- ranged to take at least a part of the load of the arch, steel-work spanning the port, and means for suspending the refractory elements from the steelwork.

8. In a soaking pit cover, a portably mounted metallic framework, ceramic refractories of 10W density and high heat resistance forming the main refractory body of the cover, a band of high density refractory elements encircling said refractories and adapted to be positioned out of the zones of highest temperature and to contact with sealing material deposited around the top of the soaking pit, and means for detachably suspending all of said refractories from said framework, so that the elements of said encircling band shall be maintained in abutting relationship to said low density refractories.

9. In a furnace cover, a. portably mounted metallic framework, ceramic refractories of low dene -sity and high heat resistance forming the main refractory body of the cover, high density refractory elements bordering said refractories and adapted to be positioned out of the zones of highest temperature and to contact with sealing material deposited around the top of the furnace, and means for detachably suspending said refractories from said framework in groups, said high density refractories being shielded by the walls of the furnace.

f JAMES E. BRINCKERHOFF.

JAMES D. MCCULLOUGH. ROSCOE E. SWIFT.