US3399046A

US3399046A - Furnace suspended skimmer wall

Info

Publication number: US3399046A
Application number: US421847A
Authority: US
Inventors: Levi S Longenecker
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-12-29
Filing date: 1964-12-29
Publication date: 1968-08-27
Anticipated expiration: 1985-08-27

Description

g- 27, 1958 L. s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL 7 Sheets-Sheet 1 Filed Dec. 29, 1964 m INVENTOR Lew .5. L ongenec/rer H/S ATTORNEYS Aug 27, 6 L. s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL Filed Dec. 29, 1964 H/S ATTORNEYS Y g- 7, 1968 L. s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL Filed Dec. 29, 1964 '7 Sheets-Sheet I 40 z m g II I, 43 M; (77. C

I20 32b 34 q INVENTOR. Lew 5. L ongenec/rer HIS ATTORNEYS Aug. 27, 968 1.. s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL 7 Sheets-Sheet 4 Filed Dec. 29, 1964 INVENTOR. Levi S. Longenec/rer gm ewa HIS ATTORNEYS 27, 1968 s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL Filed Dec. 29, 1964 7 SheetsSheet "a n INVENTOR Ff Levi .9. Longenec/rer %%m% H/S ATTORNEYS g- 68 1.. s. LONGENECKER 3,399,048

FURNACE SUSPENDED SKIMMER WALL Filed Dec. 29, 1964 7 Sheets-Sheet 6 INVENTOR. Lew .S. Longenec/rer HIS ATTORNEYS g- 7, 68 L. s. LONGENECKER 3,399,046

FURNACE SUSPENDED SKIMMER WALL Filed Dec. 29, 1964 '7 Sheets-Sheet '7 39 EZLTAHMMMMMMMMMMMMMMTTW fi m TH HTLH HTHw INVENTOR L evi 5. L angeneclrer aum hm ATTORNEYS United States Patent 3,399,046 FURNACE SUSPENDED SKIMMER WALL Levi S. Longenecker, 61 Mayfair Drive, Pittsburgh, Pa. 15228 Filed Dec. 29, 1964, Ser. No. 421,847 Claims. (Cl. 65-340) ABSTRACT OF THE DISCLOSURE A furnace, such as used for providing molten glass, has an open roof portion through which a U-shaped frame extends downwardly; the frame carries protective refractory blocks that define a downward continuation of the furnace roof and that extend above and across the flow path of the molten material in the furnace to provide a shadow wall. A skimmer wall of refractory construction is suspended downwardly between and is carried by the front and back parts of the U-shaped frame to project below a flow level of the molten material in the furnace. The construction of the shadow wall is such that it provides working space between the front and back parts and is swingably carried at its upper end portions, in order that it may be moved inwardly and outwardly with respect to the skimmer wall to permit the skimmer wall to be repaired, inserted and removed. Bottom end portions of the back and front wall parts are provided with crossextending means connected therebetween for holding them in a closed relation with the skimmer wall and for spreading them apart or moving them about the upper swingable means when the skimmer wall is to be serviced.

This invention pertains to means for skimming a hot surface portion of molten material during its movement between melting and refining portions of a furnace and particularly, to the provision of a surface skimming construction which will eliminate difiiculties heretofore encountered in connection with the use of floaters, for example, such as used for breaking up the surface flow in a window glass melting and refining furnace.

An important phase of my invention relates to providing a furnace shadow wall with a suspended skimmer which may be adjustable.

In conventional window glass melting tanks or furnaces, floaters are generally in use as positioned between melting and refining ends of the tank or furnace to break up the surface flow and prevent the hot molten glass adjacent the top surface from flowing directly to the front of the furnace. One purpose is to obtain a better depth of heating by causing the hot or top portion or layer of the molten glass to flow under the floaters.

It has been found necessary to use floaters of relatively poor quality refractory material, such as of clay brick, in order that the floater block will be light enough to float on the molten glass. The plan view of FIGURE 2 of US. Patent No. 3,137,559 shows a typical construction and mounting of floater block, as represented by 1A and 1B. Although a pot or furnace may have a width of about twenty-five feet in its melting portion or area, it is necessary to reduce this to a relatively narrow channel of about twelve feet in flowing the glass into the refining portion or area so as to employ floaters. These floater blocks, as shown in FIGURE 2 of the patent, fit in offsets or chucks along the narrow passageway or throat and are adapted to centrally-interlatch with each other. The blocks extend vertically-upwardly within the bath (see FIGURE 1 of the patent), usually about 16 inches, and, at their inner ends, have interfitting offsets to engage with each other. As long as the flow is forwardly in the direction ice indicated by the arrows of FIGURE 2 of the patent, the molten glass tends to maintain the floaters in their interlocked or interlatched positioning at their inner and outer vertical ends. However, if the molten glass flow is stopped or reversed, then the floaters tend to move out of their chucks or retaining offsets and thus require reinsertion. The floaters are difficult to replace, and after they have been in service for a time begin to absorb the molten glass and dissolve. The melting and fluxing is messy and spoils the quality of the glass produced.

Although there are better refractories available which can produce much longer service, I have found that they are too heavy to float. A typical better refractory block is a so-called fusion cast block, such as made by Corhart Refractories Company. The low density type of refractory that is suitable for floating useage, soon loses its thickness, tends to become liquid-logged and falls into the bath below a desired submergence of about 16 inches. If it is too shallow or not wide enough, it becomes ineffective as a floater, it then must be fished out and replaced with a new one. The idea of cooling the floaters, as suggested by Patent No. 3,137,559, has been found to be disadvantageous from the standpoint that it cools the hot layer of glass whose temperature is to be maintained.

Although in the bottle manufacturing field it has been customary to use a bridge wall in a furnace, the flow of the molten glass is through ports or openings in the bridge wall which produces only a localized mixing action and below the surface layer. Also, I have found that it is desirable to skim off floating impurities adjacent the top surface of the molten bath so as to produce top quality glass.

It has thus been an object of my invention to solve the problem presented by the present use of refractory floaters in a melting tank or furnace, such as may be used in producing higher quality glass, for example, window glass, by an entirely new approach thereto;

Another object of my invention has been to eliminate the disadvantageous features of a conventional floater system by providing a skimmer system which will be top-suspended with respect to the molten material;

Another object of my invention has been to devise a construction or system which will not only meet the disadvantageous features and improve on the advantageous features of a floater system, but which will make possible the use of high quality refractory blocks, irrespective of their density or ability to float;

A further object of my invention has been to devise a suspended skimmer construction or system that will extend downwardly from an overhead wall, such as a suspended shadow wall, and that may be adjusted as to its depth of submergence in the molten material;

A still further object of my invention has been to provide a skimmer wall construction whose contour of skimming action may be adjusted to produce a so called combing type of action on the melt across its width;

A still further object of my invention has been to provide means for retarding the surface flow of hot molten material along a glass tank which can effectively utilize a maximum or full width of the tank between its melting and refining portions or areas;

These and other objects of my invention will appear to those skilled in the art from the illustrated embodiments, the description and the claims.

In the drawings,

FIGURE 1 is an end section in elevation through a construction employing my invention which is in the nature of a U-shaped suspended shadow wall having a suspended skimmer;

FIGURE 2 is a top plan section on an enlarged scale and taken along the line II-II of FIGURE 1;

FIGURE 3 is an enlarged side section on the scale of FIGURE 2 and taken along line III--III of FIGURE 1; this view particularly illustrates the construction and mounting of skimmer block;

FIGURE 4 is an enlarged sectional detail on the scale of FIGURES 2 and 3 of the right-hand portion of the construction of FIGURE 1;

FIGURE 5 is a perspective view in elevation of a hanger part for skimmer block shown particularly in FIGURES 1, 3 and 4;

FIGURE 6 is a perspective view in elevation on the scale of FIGURE 5 showing details of the construction of a nose hanger for nose block, such as employed at the right and left-hand sides of the shadow wall construction of FIGURE 1;

FIGURE 7 is a side section in elevation on a reduced scale with respect to FIGURE 1, illustrating the relationship of a skimmer block line of my invention from the standpoint of a flow section of a furnace or pot;

FIGURE 8 is a view on the scale of and similar to FIGURE 3 illustrating how a skimmer block may be raised and lowered to adjust it or to remove it for maintenance and repair;

FIGURE 9 is a view similar to and on the scale of FIGURE 1 illustrating a first step of spreading front and back portions of the shadow wall for inserting or removing block of a skimmer line; it also shows a skimmer block in a raised position ready to be removed or inserted. For the first step, opposed halves or portions of the shadow wall are shown pivoted outwardly to increase the spacing adjacent the skimmer line;

FIGURE 10 is a fragmental end section in elevation of a modified construction with respect to and on an enlarged scale as to the embodiment of FIGURE 1, wherein cooling means may be utilized between opposed end blocks of the shadow wall and a centrally-positioned skimmer line of block;

FIGURE 11 is a fragmental side section on the scale of and taken along line XI--XI of FIGURE 10;

FIGURE 12 is a fragmental end section in elevation on the scale of and of the type of FIGURE 10 illustrating another embodiment of my invention;

FIGURES 13 and 14 are reduced somewhat diagrammatic side views in elevation illustrating how skimmer block of the construction of FIGURE 12 may be adjusted or arranged to provide any desired or suitable type of combing action on the surface of the molten material; and

FIGURE 15 is a fragmental end section in elevation on the scale of and of the type of FIGURE 12 illustrating a further embodiment of my invention.

In accordance with the concept of my invention, I incorporate a skimmer structure or block line with a suspended shadow wall, such as used in melting furnaces and particularly, in glass melting furnaces. The skimmer block are suspended or positioned to project downwardly substantially centrally from the shadow wall in such a manner as to extend below the surface level of the molten material or glass to accomplish the desired skimming action. The shadow wall construction has been modified to accommodate a skimmer wall or its suspended line of refractory tile or blocks, and to do so in such a manner that the blocks may be readily replaced and, if desired, adjusted with respect to the depth of immersion along their line, as well as with respect to each other, so as to provide a new type of skimming action in the nature of a combing or variable profile action with respect to or across the flow of molten material. The skimmer block, as employed in accordance with my invention, are no longer floater block, and are positively suspended and held in position. They may be adjusted as to their depth of positioning in accordance with the needs and requirements of a particular operation.

Although the shadow wall may, itself be vertically adjustable, I have devised means for adjusting the skimmer wall independently of the shadow wall, and for inserting and removing the skimmer wall and its individual blocks from their positioning with respect to the shadow wall. Where a U-shaped shadow wall is employed, it is made partible with respect to its front and back wall parts or pivotal with respect to the skimmer wall, not only in order to enable and facilitate the insertion and removal or replacement of the skimmer wall blocks, but also to incorporate the skimmer wall as a closing-off refractory structure with cooperating portions of the shadow wall. The spacing between the front and back wall parts, as defined by the metal supporting framework of the shadow wall, is utilized to enable workmen to adjust the skimmer wall block and, as by means of an overhead hoist, to insert and remove the refractory blocks of the skimmer wall.

The refractory block or tile used in the skimmer wall, by reason of its method of utilization, can now be of a high quality fusion cast block type having a relatively high density and a maximum operating life. The suspension of the individual blocks of the skimmer wall has been devised to facilitate their insertion and removal and, at the same time, to enable their cooperative utilization with the adjacent blocks or block tiers of the shadow wall, to close-off the furnace, and to protect the metal framework from which the refractory blocks are mounted or suspended. The shadow block, in accordance with my invention, may consist of large unitary block members positioned longitudinally along the skimmer block line (see FIGURES 4 and 7), may consist of abutting groups of refractory block or tile instead of a unitary tile taken transversely of the skimmer wall (see FIGURE 15), and may incorporate Water-jacketing or cooling fluid piping in connection with their utilization (see FIGURE 10).

In the drawings, embodiment A is shown in FIGURES 1 to 9, embodiment B is shown in FIGURES 10 and 11, embodiment C is shown in FIGURES 12 to 14, and embodiment D is shown in FIGURE 15. These embodiments are illustrative of the adaptability of a construction of my invention.

Referring to FIGURE 1 of the main embodiment A, 10 and 10' represent adjacent portions of the refractory furnace roof which define a spacing through which a sus pended shadow wall may be positioned. The shadow wall of FIGURE 1 has a front vertical frame member structure 11 and a back vertical metal frame member structure 11 which support or suspend front and back halves or parts of the wall. As illustrated particularly in FIGURES 1, 7 and 9, the frame structures 11 and 11' are, at their upper ends, pivotally or swingably suspended from mounting bracket pairs 11a 'by means of pivot pins 16 and 16', respectively. The mounting brackets 11a are secured to project downwardly from the bottom flanges of a pair of cross-extending overhead support beam members 12 that have a fixed mounted relation and comprise a part of the overall furnace structure. A series of spaced-apart metal angle pieces or members 13 rest on the upper side of the inner portions of the lower flanges of the support beams 12 and may be weld-secured thereto to suspend an overhead I-beam shaped rail 14 for a conventional monorail hoist 15.

As shown particularly in FIGURES 1 and 7, the hoist 15 has flanged wheels which are adapted to roll or move alongthe rail 14, in order that the hoist may be moved to any working position above the skimmer block line for inserting or removing a particular block of the line. Also, as shown, the hoist 15 has a hoist chain carrying a hoist hook 15a. In FIGURE 8, the hook 15a is shown engaged within an eyelet bolt 41a of a supporting suspending structure of an individual block 35.

Vertically spaced-apart channel members 17 are shown secured, as by welding, along the outer flanges of the members of the frames 11 and 11', and are provided with top angle pieces for detacha-b'ly-mounting hanger castings 18 for front and back vertical

refractory block tiers

24, 25 and 26 of the shadow wall. As shown particularly in FIGURES 1, 3, 4 and 9, lower pairs of longitudinallyextending I-

beam members

19 and 20 are secured to project downwardly from each

frame structure

11 and 11. The outer beams 19 of each pair also have top angle pieces for mounting lower or nose hanger castings 18 which may be similar to those disclosed in \my Patent No. 2,806,452, see particularly FIGURE 11 thereof. The spacing between top flanges of each spaced pair of bottom I-

beam members

19 and 20 is closed-off by a top connecting plate member between them and the frame structures 11 and 11'. The spacing between the bottom flanges of each pair of

members

19 and 20 is closed-off by a do sure plate member 21, so that each pair of

members

19 and 20 defines an air manifold for circulating cooling air. Spaced openings 21a (see FIGURE 9) may be provided in each closure plate 21 for flowing the cooling air along the hangers and against the inner ends of the suspended refractory block and generally, along the inner areas of the refractory blocks.

The upper tiers of vertical tile or blocks 24 have a slight inward spacing or clearance-defining relation with the end portions and 10 of the furnace roof, so as to permit the front and back portions of the shadow wall to be swung or pivoted from the closed position represented by FIGURE 1 to a downwardly-open or outwardlyswung position represented by FIGURE 9.

Upper closure tile

27 and 27 are mounted in a slide-permitting relation to close-off such spacing in cooperation with the furnace roof portions 10 and 10' and the upper block tiers 24.

The lower hanger castings 18' carry refractory nose block 28 and cooperate with central support brackets 31, see also FIGURE 6, which latch with shoes 30 of the brackets 18' and engage within the nose 'block 28. Horizontal or underpositioned tile block tiers 29 project from the nose block tiers 28, along the bottom of the shadow wall, and terminate in end blocks 29a which define an open spacing therebetween and along the longitudinal extent of the shadow wall within which a line of skimmer block, such as 35, are to be suspended. The end blocks 29a are removably-secured in position by end abutment plates or brackets 33 that, in turn, hold the lower block tiers 29 and the nose block 28 in position. An angle-shaped end closure plate member 34a fits over the bottom flange of the beam 20, under a clamp 34. The clamp 34 is secured by a bolt and nut assembly to a flange of the casting 32. Each end bracket 33 is secured in position by bolts 33a that are mounted in side lugs 32b of an associated casting 32. The refractory blocks of the lower tiers 29 are suspended from horizontally-extending bracket castings 32 which have a cooperative slidably-mounted engagement with the lower flanges of the members 19 and of the lower beam member pairs. As shown in FIG- URE 4, one end of each casting 32 has a hook portion 32a to engage the lower flange of the beam 19 and its opposite end is removably-clamped over the bottom flange of the beam 20 by the clamp 34. The general construction is disclosed in my Patent No. 3,139,846.

As shown particularly in FIGURES 1 and 9, the refractory skimmer block 35 are of rectangular shape, see also FIGURES 3, 7 and 8, and are provided with round or circular side slots, recesses or depressions 35a to receive inwardly-projecting latching lugs 36:: of complementary pairs of hanger brackets 36 which define an assembly. FIGURE 5 shows the details of the construction of each part or half of the assembly. It will be noted that each part of 36 is of angular shape and has an inwardly-positioned and upwardly-projecting leg portion 36b which is adapted to cooperate and abut with a similar leg portion of the other half or part of the assembly to receive upper and lower nut and

bolt assemblies

37 and 38. In this manner, the bracket assemblies 36 can be removably-held in a clamping-on relation with respect to each skimmer block 6 35. As shown in FIGURE 3, there are two assemblies 36 employed for each skimmer block 35.

With particular reference to FIGURES 2 and 3, it will be noted that I have provided an overhead rectangular supporting or hanger frame 42 for each skimmer block 35. The frame 42, as also shown in FIGURES 1 and 9, is made-up of angle pieces joined at their ends and is adapted to removably and slidably rest upon the top flange of the inner beam members 20 of the beam member pairs 19 and 20. As shown particularly in FIGURE 2, each frame 42 may be provided with a top grating 43 to enable a workman to walk thereover and along the line of the skimmer blocks. Each hanger bracket assembly 36 of the pair of assemblies for each block is, at its upper end, secured within a downwardly-projecting U-shaped bracket end portion of a threaded suspension bolt or pin 39 by means of the upper bolt and nut assembly 37. Each threaded suspension pin .or bolt 39 projects through an opening in a cross-extending supporting angle piece or member 41 which is adapted to removably rest upon opposite side members of an associated support or suspension frame 42. As shown particularly in FIGURES 2 and 3, each cross piece or member 41 adjustably supports a pair of suspension bolts 39 in a spaced relation with each other, and nut pairs 40 carried by each bolt 39 enable it to be adjusted vertically on the piece 41 to give a certain amount of vertical adjustment for each skimmer block 35.

When a skimmer block 35 is to be raised into and .out of position, the hook 15a of the overhead hoist 15 may be moved into engagement with eyelet 410 that projects centrally-upwardly from an associated cross member or piece 41, see particularly FIGURE 8. Where it is desired to provide a combing action by, in effect, adjusting skimmer block 35 along the skimmer block wall line so as to produce a combing action, as illustrated by representative FIGURES l3 and 14, this can be accomplished by adjusting the vertical positioning of each block by means of its pairs of suspension bolts 39 and with respect to its associated frame 42 and from the standpoint of its associated cross support piece or member 41.

As shown particularly in FIGURES 2, 3 and 7, the inner beam members 20 are, adjacent their ends, connected together by an adjustable jack 45. Each end of the jack 45 is carried by a pivot pin assembly 46 on a bracket mounting assembly 47 that is secured to the top flange of an associated I-beam 20. The inner ends of the rods of jack 45 are threaded and project into and are adjustable with respect to each other by means of a central turnbuckle 45a. The turnbuckle 45a may thus be employed for adjusting or controlling the spacing between the opposed I-beam members 20 and thus, the spacing between the inner ends of the front and back shadow wall parts and particularly, between the end block 29 in order to open the spacing (as shown in FIGURE 9) when a skimmer block is to be removed or inserted, and to close the spacing (as shown in FIGURE 1) when the wall construction is to be closed for furnace utilization. The turnbuckle 45a or any other suitable means of adjustment may be thus employed to swing the frames 11 and 11' about their pivot suspension pins 16 and 16' and to retain them in a desired spread or closed relation with respect to each other.

In the construction B shown in FIGURES 10 and 11, I have disclosed cooling means (hairpin type coolers) interposed between the skimmer block line and the end tile of the shadow wall. In order to protect vertically-superimposed side-mounted pipe pairs 63 and 64, intermediate block 50 slope outwardly-downwardly from the bottom block tiers 29 of the shadow wall and cooperate with downwardly-projecting end blocks 51 to define a shielded spacing along opposite sides of refractory block 52 of the skimmer block line. The general construction of the shadow wall is otherwise substantially the same and similar reference numerals are used for corresponding parts of the embodiment of FIGURES 1 to 9, inclusive. The

skimmer block 52 are shown of a slightly different con struction, in that groups are carried by secondary cantilever hanger brackets 53 which engage with a central or primary cantilever hanger bracket 54. Each main bracket 54 is adapted to slidably-fit on or over the bottom flange of an associated one of a series of cross-extending and spaced-apart support I-beam members 55. Each I-beam member 55 is adapted to slidably and removably rest on inner flange portions of the inner I-beams 20.

In this construction, grating 41 may extend along the full length of the skimmer block line, since the individual frames 42 of the construction of FIGURE 2 are eliminated. The cross-extending support beam pieces 55 may (see particularly FIGURE be tilted within the spacing between the inner I-beam members 20 for removing and inserting a skimmer block group and its supporting primary cantilever bracket 54. The type of suspension of the skimmer blocks 52 and fitting of the

cantilever brackets

53 and 54 with respect thereto is illustrated in my Patent No. 2,612,124, see particularly FIGURES 1, 2 and 3 thereof. The only dilference is that a primary bracket 54 is used which is engaged by the brackets 53 and which, in turn, has a leg engaging within side slots of blocks 52 in the same manner as the secondary brackets 53. The use of the central or primary brackets 54 permits the provision of spacing between the bottom flange of the beam pairs 19 and 20 and the top ends of the blocks 52 for circulation of cooling air.

The piping pairs consisting of

pipe members

63 and 64 are shown suspended by means of downwardly-projecting latch mounts 60 which are secured, as by welding, to the underside of the beam pieces 55. A supporting arm 61 is secured to the top pipe 63 of each pair and has a projecting latching pin 61a that is adapted to removably-engage within a latching slot of an associated latching mount 60. The lower pipe 64 is carried by the upper pipe 63 by means of a connecting lug 62 which is secured, as by welding, therebetween. It will thus be apparent that each pair of

pipe members

63 and 64 is detachably-carried by a series of support arms 61 from the cross pieces 55 and thus, that they can be removed from their support suspension mounts 60 independently of the skimmer block 52 and, if not dismounted therefrom, may be lifted out of position along with the skimmer block 52 when the I-beam pieces 55 are lifted. The side-mounted pairs of cooling

fluid circulating pipes

63 and 64 preferably extend to the center of the furnace, so that they can be easily pulled-out for repair and replacement. In this construction, the skimmer block 52 can be inspected, removed and inserted by lifting-otf the grating 41', but are not adjustable in the sense of the embodiment of FIGURES 1 to 9, inclusive. In the group skimmer block arrangement of FIGURE 11, filler blocks 52' are inserted between end blocks of skimmer block tiers.

In the embodiment C of FIGURE 12, the general construction is the same as that of FIGURE 1, except that intermediate block 50 and end block 51 are of the construction shown in the embodiment B of FIGURES 10 and 11, to provide additional protection for the skimmer block 35. It will be noted that molten glass surface level L is maintained below the bottom ends of the

blocks

50 and 51.

As previously intimated, FIGURES 13 and 14 illustrate typical combing arrangements of the skimmer block 35 that may be utilized along the skimmer block line. In this connection, FIGURE 13 employs a centrally-inwardly concave type of outline or profile, while FIGURE 14 employs a centrally-convex type of outline or profile. The vertical extent of the blocks 35 may also be selected for the particular type of combing action desired, in addition to the adjustment which is made possible by the suspension bolts 39. For example, in FIGURE 13, the central blocks which are the highest positioned blocks of the line may be used. to merely skim-off impurities along the upper surface of the melt, while those along the ends of the line may be employed with different depths of extension to cause the surface layer of the molten material to flow down at different levels. In FIGURE 14, the opposite is true, in that the central blocks having the greatest depth of extension within the motlen material will serve to cause the surface level of glass to flow down into the body of the glass, while the end blocks will provide a surface skimming action.

In the embodiment D of FIGURE 15, I employ a centrally-extending vertical metal frame structure 11" which serves as a common support for both the front and back parts of the shadow wall. The frame 11" carries crossextending angle pieces 75 which are secured thereto and have secured-on end-positioned angle pieces 76 for engagement with the hanger castings 18. A lower I-beam 77 is secured to the lower end of the frame 11" through the agency of a top closure plate 80. A box-like enclosure is formed about the beam 77 by the top plate 80, side closure plates 82, and a bottom closure plate 78. The side plates 82 are secured by angle pieces 81 to the top closure plate 80, and the bottom closure plate 78 is secured to and suspended from the web of the beam 77 by angle pieces 79. Angle pieces extending from the ends of the bottom closure plate 78 cooperate with the side closure plates -82 to define flow passageways 83 for the outflow of cooling air from the box enclosure to the inner supported end area of the refractory blocks.

It will be noted that skimmer block section is made-up of a group of transverse blocks 71 which are supported by secondary cantilever hangers 72 and a central or primary cantilever hanger 73 in a manner similar to the support of the blocks 52 of FIGURE 11, but as there accomplished longitudinally along the skimmer block line. It will be noted that the central hanger 73 is slidably-carried on the bottom flange of the beam 77, and that end blocks 70 which cooperate with nose block 28 of the shadow wall are also carried by the cantilever hangers 72.

From the above description, it will be apparent that I provide a skimmer wall made up of individual refractory blocks in an abutting and closing-off relation with each other, that extend as a line across the furnace or across the flow path of the molten material therein, and that project centrally-downwardly from the shadow wall through a central window or opening therein or between its front and back protecting refractory blocks or tile. Each skimmer block or each skimmer block group across the width of the skimmer wall, is adapted to be independently suspended with respect to adjacent abutting blocks or block groups along the longitudinal extent of the skimmer wall. The skimmer wall cooperates with the refractory blocks of the shadow wall to close-off the inside of the furnace when it is in operation. However, the blocks of the shadow wall in their mounted positioning may be swung away from abutment with the blocks of the skimmer wall for adjusting, inserting or removing the blocks of the skimmer wall, utilizing spacing between front and back parts of the shadow wall. The shadow wall projects downwardly through an open portion in the roof of the furnace and across between side Walls thereof or across and above a flow path. of molten material in the furnace; it terminates above the melt line or surface level of the furnace.

In carrying out my invention, I have found that it is important to seal-01f the furnace roof so as to avoid the loss of heat and to do so in such a manner as to fully protect the metal frame structure. I also have found that it is important to eliminate an outside end suspension for the skimmer wall. This avoids any possibility of the sagging of the heavy blocks of the skimmer line, provides a stronger and more stable support, and simplifies the maintenance and repair of the skimmer wall. At the same time, I enable the blocks of such line to have an easilyremovable, abutting, sealing-off relation with respect to each other, and an abutting, sealed-off relation with the refractory blocks or tile of the shadow Wall that will be effectively maintained under the high temperatures involved and under the expansion and contraction incident to variations in temperature and to the heating-up and cooling-down of the furnace.

It will be noted in this connection that -I have made use of a primary overhead metal support frame whose secondary member or frame structure projection downwardly through a transverse opening in the refractory roof of the furnace and into the furnace chamber to support a cross-extending frame structure having at least a pair of cooperating members or a box-like metal frame structure of a type that defines a cooling-fluid flow chamber therealong. The construction is also such that when the furnace is shut down, workmen may enter the furnace through the opening defined in the roof and directly work in a longitudinal or cross-extending area immediately above the skimmer wall and within the front and back parts of the protective refractory blocks of the shadow wall in such a manner as to readily adjust and replace individual skimmer wall blocks.

The construction is devised in such a manner that the same overhead primary frame work which supports the shadow wall may be used for supporting the skimmer Wall, to enable the maintenance of the full sealing-off relation between the protective block of the shadow wall and the refractory block of the skimmer wall and to, at the same time, enable workmen to adjust and replace individual blocks of the skimmer wall without removing the blocks of the shadow wall and without disturbing adjacent blocks of the skimmer wall. I have provided means for adjusting the spacing between the opposed sides or parts of the protective shadow wall and with respect to the skimmer wall, in order that the parts of the shadow wall may be opened or swung-out from the skimmer wall dur ing the repair or maintenance work, and may then be adjusted to a suitable sealing-off relation with the skimmer wall when the furnace is to be put back into operation.

Adjustment means is also positioned within the spacing between the opposed parts of sides of the shadow wall and is readily available to the workmen. It retains any desired adjusted relation between the wall parts so as to insure the full overhead sealing-off of the furnace wall structure. The construction is also devised in such a manner as to fully protect the metal frame work, that is, the basic overhead frame work, the secondary frame work which projects downwardly into the furnace chamber and the cross-extending frame work, from the hot gases as well as from the heat of the furnace during its operation. The construction is such that the supporting and adjusting parts are, in effect, isolated and protected from the furnace atmosphere, although they are positioned within the furnace chamber from the standpoint of the main furnace roof or arch.

Although I have shown illustrated embodiments to exemplify my invention; it will be apparent to those skilled in the art that various modifications and utilizations may be made in accordance with my invention without departing from its spirit and scope.

What I claim is:

1. A wall construction for a melting furnace having a refractory roof provided with an open portion therein that extends thereacross, a U-shaped metal support frame projecting downwardly within the open portion of the furnace roof and carrying refractory block to provide a shadow wall within the furnace, said shadow wall defining an open central portion therealong across the furnace, a skimmer wall positioned within the open portion of said shadow wall, means suspending said skimmer wall from said support frame in a cooperating closing-off relation with said shadow wall to project downwardly within the furnace below said shadow wall, means carried by said support frame and cooperating with said skimmer wall for raising and lowering it with respect to said shadow wall, and means swingably suspending said shadow wall within the furnace for opening and closing movement with respect to said skimmer wall.

2. A wall construction as defined in claim 1 wherein, said skimmer wall comprises a group of abutting refractory blocks, and rectangular hanger frames cooperate with said suspending means for carrying each of said refractory blocks on said support frame independently of the others.

3. A Wall construction as defined in claim 2 wherein, said suspending means comprises, a pair of hanger assemblies engaging each refractory block of said skimmer wall and projecting upwardly therefrom, a pair of threaded rods for each pair of hanger assemblies, one threaded rod of each of said pairs being secured at its lower end to one hanger assembly and the other threaded rod of each of said pairs of rods being secured at its lower end to the other hanger assembly of the same pair of hanger assemblies, said threaded rods projecting upwardly from said hanger assemblies, cross pieces carried by each of said rectangular hanger frames to receive upper end portions of the threaded rods of each of said pairs, and adjustable nuts on the upper end portions of said rods for adjusting the vertical positioning of an associated refractory block.

4. A wall construction as defined in claim 2 wherein, said shadow wall has front and back wall parts, a hoist is mounted for movement along said support frame between said front and back wall parts of said shadow wall above said skimmer wall, and each said cross piece has means projecting therefrom for engagement by said hoist for lowering and raising each refractory block of said skimmer wall between said front and back shadow wall parts.

5. A wall construction as defined in claim 4 wherein, means swingably mounts said front and back wall parts of said shadow wall on said support frame, and adjustable means connects the front and back wall parts for moving said wall parts inwardly and outwardly with respect to each other to open and close said shadow wall with respect to said skimmer wall.

6. In a furnace having an open roof portion, a metal support frame of U-shape having front and back parts projecting down-wardly through the open portion of the roof, protective refractory blocks carried by and projecting from the front and back parts of said support frame and defining a downward continuation of the furnace roof to extend above and across a flow path of molten material in the furnace and provide a shadow wall construction, hanger frame structure carried by and between lower end portions of the front and back parts of said support frame, a skimmer wall of refractory construction suspended from said hanger frame structure and extending centrally-downwardly between and below refractory block carried by the front and back parts of said support frame to project below a flow level of the molten material in the furnace, and said support frame having swing means connected to upper end portions of said front and back parts for swinging them inwardly and outwardly with respect to each other to move said protective refractory blocks into and out of a closing-off relation with said skimmer wall.

7. A furnace as defined in claim 6 wherein said support frame has portions at the bottom end thereof that define air manifolds therealong behind said protective refractory blocks and longitudinally along and above opposite sides of said skimmer wall.

8. A furnace as defined in claim 6 wherein, cooling means is carried by said support frame between said protective refractory blocks and said skimmer wall, and said protective refractory blocks have end blocks along said skimmer wall that project downwardly therealong beyond adjacent protective refractory blocks to protect said cooling means.

9. A furnace as defined in claim 6 wherein, support means is provided for removably-suspending said skimand for moving them inwardly and outwardly with re- 5 spect to each other on said swing means to provide for inserting and removing said skimmer wall.

10. A furnace as defined in claim 9 wherein hoist means is carried by said back and front Wall parts adjacent upper end portions thereof to engage said support means for raising and lowering it with respect to said shadow wall.

1 2 References Cited UNITED STATES PATENTS 1,321,752 11/1919 Jones 65345 2,098,440 11/1937 Tassick 65345 3,183,072 5/1965 Long 65-333 FOREIGN PATENTS 631,040 6/ 1936 Germany.

10 DONALL H. SYLVESTER, Primary Examiner.

FRANK W. MIGA, Assistant Examiner.