US1464248A - Muffle furnace - Google Patents

Description

Aug. 7, H923. 11,464,248

C. F. GEIGER MUFFLE FURNACE Filed May 31. 1922,

INVENTOR ATTORNEY? lf atented' u I, 1923.

PATENT OFFICE.

CHARLES 1F. GEIGEB, 0F PERTH AMJBOY, NEW JERSEY, ASSIGNOB TO THE CAR- IEBORUNDUM COMPANY, @F NIAGARA PENNSYLVANIA. I

EUFFLE Application flleu May 31,

To all whome't may com-em:

Be it known that I, Cinema GEIGEIR, a citizen of the United States, residing at Perth Amboy, county of Middlesex, State of New Jersey, have invented a new and useful Improvement in Muflie Furnaces, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure l is a partial horizontal section on the line I-I of vrigure 2;

Figure 2 is a transverse vertical section; and

Figures 3 and 4 are perspective views of two forms of tile which I prefer to employ.

My invention relates to muflie furnaces wherein the material to be heated is out of contact with the combustion gases and particularly to a new and improved construction for the roof and side walls of the mufiie chamber.

I will now describe'my invention as applied 'to'a me furnace, such as used in tit \ ename of iron or steel or burning terra outta, it being understood that it may be appliedto any mufiie furnace. In such a furnace, there is an internal closed chamber or -rne having substantially vertical side walls and an arched roof-with spaces beneath the fioorg around the sides, and above the roof of the muflie, for the circulation of combustion gases, the mufiie being surrounded by an enclosing structure containing the combustionchambers. The combustion chambers are ordinarily beneath or adjacent to the floor of the mufile, "and the gases after bein discharged underneath the floor are led up ilm fines at the sides of the furnace between the outside and side walls, and thence along the roof between the outside and inside arches and then discharged. In an cases, thegases are closed ofifrom the mue chamber, since in this class of work it is necessary to keep the gases away from the articles bein treated.

In the mu Iii furnaces, the wall of the mufile acts to isolate the atmosphere inside the mufie chamber from the combustion gases, and at the same time conduct heat from the gases into the chamber. It is desirable that the mufile walls should be thin, so that the greatest amount of heat may be transmitted,

but it is diflicult to obtain this object while FALLS, NEW YORK, CORPORATION OF FURNACE.

1922. Serial No. 564,868.

retaining the proper structural strength. The roof of the mufile has ordinarily been made of slabs of a considerable thickness,

necessary to give proper strength and bear- 1long at the edges and provide proper sta- 1 lty.

In accordance with my invention, the side walls and arches of the muffle are formed of hollow tile, this being particularly important in the roof arch construction.

In the drawings, 2 represents the general masonry structure of a muflie furnace containing a'muifle of which the s de walls are formed of hollow tiles 3, and the roof arch is also formed of hollow tiles 4:. The end Walls of these hollow tiles may be and preferably are provided with alternate grcjections and recesses 5 and 6, so that one row of tiles will interlock with the adjacent rows and give intersupporting of the rows. This, however, may or may not be used as desired. The fire boxes indicated at 7 are preferably staggered on opposite sides of the mufie chamber so that the gases of combustion from one side will pass through their flues around the mufie in a direction opposite to those in the fire box on the opposite side. This compensating arrangement gives greater uniformity of temperature in' the mufle because the hottest gases from one part of the furnace will heat a section next adjacent to the .part where the cooler gases from the opposite fire boxes pass.

In the form shown, the gases leaving the tire box divide, a portion of them passing through the flues 8 underneath the fioor of the muflie and up the side flue 9 to the exit flue 10, while the other portion passes up through the side flues 11, thence throu h the roof arch flues and to the other exit ue at 12. The exit flues are preferably provided with dampers 13, so that the flow of gases in either direction may be better controlled.

b Instead of dividing the gases at the fire ox boxup the side flue, over the top of the arch, down the other side fine and then back through the bottom flue to an exit flue adjacent the firebox.

The tiles are preferably made of bonded A 105 siliconcarbide, as this 'v'es greater structural strength and high vt ermal conductivity at high temperatures; For example, if I use a tile of a cross section of six inches in- 30 out departing from my invention.

' side dimensions, withthe side walls of the tile one-half inchthick, I can obtain all the stability of a wall or arch six inches thick,

. and at the same time, obtain the conductivity hollow tiles, and thence being carried across chamber.

and under the roof of the mufile in the form of an arch. This will give a larger radiating surface from the tile into the muflie, since' the roof tiles will-be in the muflie Again, instead of the self-supporting arches of square or rectangular tiles, as shown, I may employ cylindrical tiles, or tiles of other cross sectional shape, each arch being a self-supporting unit. These arches may be laid close together, whether interlocked or not, or may be spaced apart, if desired.

The furnace may be used for many pur-' poses, and other changes may be made with- I claim:

1. In a, muffle furnace, a muflie having in its roof hollow tiles forming a self-supporting arch and arranged to form a flue for products of combustion, said tiles being of uniform thickness throughout their length and joined together end-to-end without overlapping portions.

In amuflie furnace, a mufiie having it roof portion formed of hollow tiles forming a self-supporting arch comprising a plurality of flues, and means for directing combustion gases through the fiues formed by said tiles, said tiles being of uniform'thickness throughout their length' and the tiles in each flue being joined together end toendwithout overlapping portions.

3. In a muflie furnace, a mufile having its roof portion formed of hollow tiles forming a self-supporting arch and constructed and arranged to form a plurality ofinterlocking fiues, and means for directing combustion tiles.

side walls formed of superimposed hollow tiles forming a flue for combustion gases, said tiles being of uniform thickness throughout their length and joined to gether end-to-end without overlapping portions.

5. In a mufiie furnace, a mufile having its side walls and roof containing combustion flues formed of hollow tiles, the tiles of the roof forming a self-supporting arch, said tiles being of uniform thickness throughout their length and the tiles in each flue being joined together end-to-end without overlappin r port1ons.

6. A mu e furnace having its side walls formed of hollow tiles constructed and arranged to form a plurality of interlocking flues, and means for directing combustion gases through the flues formed of said tiles.

7. A mufile furnace having the mufile with its side walls and roof formed of hollow tiles forming fines for combustion gases, the "rows of tiles interlocking with each other.

In testimony whereof I have hereunto set my hand.

- CHARLES F. GEIGER.

gases through the flues formed by said 4. In a mufile furnace, a muflle havingits;

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