US1415424A - august - Google Patents

Description

J..R. C. AUGUST` MUFFLE FURNACE.

APPucmoN man mw 8.1920. 1,41 5 ,424. Patented May 9,1922. Eers- 2 SH SHEET I.

' v f fa@ Q5-@$2 www UNITED STATES PATENT orifice.

JOHANNES ROBERT CARL AUGUST, or HALIFAX, ENGLAND.

Application led'May 8,

To all whom t may concern: i

Be it known that I, JOHANNES ROBERT CARL AUGUST, subject of the King of Great Britain, residing in Halifax, in the county of York and Kingdom of England,have invented certain new and useful Improvements in or Relating to Muiile Furnaces, of which the following is a specification.

This invention has reference to rotary muiile furnaces of the type in which the muiiie or barrel is concentrically mounted and supported within a rotary heating chamber or furnace so that while both revolve together spaces ,are left between them,` and in which the electrically produced heat is made use of to heat the muffle. y

The invention kwill be understood from the followingidescription reference being had to the accompanying drawings, in which Figure l is a longitudinal section of my furnace, and

Figure 2 is a similar view showing a modication. l

Referring to Figure l, the rotary furnace comprises a cylindrical metal casing 20 lined inside with fire clay Slabs 2l, and extends in a horizontal or slightly inclined direction,

and the barrel orvmuiiie 22 is supported con' cent'rically inside the casing 20. At one end,

the rotary casing has a circular concentricr aperture 25, and the barrel 22 which may be y made of fire clay is closed at ythe inner end, while inside this barrel 22 and fairly `closely fitting it, is a movable container 49 to receive the articles which are to lbe subjected to heat treatment. This container 49 which may be of metaljs inserted through the cen-- tral aperture 25 of the rotary casing 20, and

rthrough the open end ofthe barrel 22, and

the open end of this container is provided with a removable gas tight cover or closure 27. The outer end of the container which may be enlarged a little as shown,extends a little beyond the end of the cylindrical casing 20, and its cover may consist of a plate 27 secured by nuts and set pins tothe lianged outer end of the container 49, and may carry on its inner side by meansof rods, an inner plate or diaphragm 27X which abuts against. the shoulder at the junction between the container proper and its enlarged end. By the removal of this cover, the articles to be subjected to heat treatment, can be readily v intro duced and afterwards withdrawn. The barrel 22 is xedly supported inside the MUFFLE FURNACE.- f

192,0. Serial No. 379,995.`

specication of Lette'rsratent. Patented May' 9,1922.

lic bands 3l cooperating with thek carrying rollers 30 resist taryfurnace. The disposition of the parts enablesthe container 49'to be withdrawn at anytime required without disturbing the outer casing 20 or the barrel 22. The electric heater is shown at 4 l This consists of a heating coil ofkwire wound round the barrel 22 so as to be supported thereby and designed to receive 'a current of electricity, and to produce by resistance heating effects.` coils 46` are insulated fromthe outer casing 2O by a supplementary casing 22 of ireclay and y a surrounding casing of insulating material 50 such as asbestos, mineral wool or the like, both around the barrel 22 `and at the inner end thereof, that is to say in the annular space between the casing 2O and the barrel 22, and in the space between the end of the barrel and the casing. The insulating material 50 keeps the coil spaced apart without danger of accidentaldisplacement. For supplying current to the electric heater 46 there-.is arranged upon the outside ofy the longitudinal play of the ro-u These heating and bearing against these contact ringsare brushes (not shown) carried by suitable supports. The heater 46 is connected through the wires 51` with the outer rings 48. Cooperating with these parts is a switch board which is connected to the source of electrical supply.

'The furnace shown in Figure 2 is similarto that described in Figure l, except that in Figure 2 the electric heater 47 consists of some substance in a powdered granulated or compound state capable of producing by resistance heating eects, as for instance ferifo-silicon, of suitable compositions and re Sistances. 20 as before is the outer metallic casing lined inside the fire clay slabs 2l, 22 the barrel or Inutile supported concentrically, 25 the circular concentric aperture, 49

the metal container, 27,27x the cover there- CII inder 52 is interposed in the annular space between the barrel 22 and the outer casing 2O so as to torni an. annular chamber between the barrel 22 and the said cylinder 52, in which chamber the powdered material. 4:7 is packed, and an annular chamber between the barrel 22 and the outer easing 2() in which chamber insulating` material 50 is inserted such as asbestos, mineral wool or the like, so as to insulate the heating unit 47 and the cylinder 52 from the outer casing,` 20. The chamber in which the heating,` unit is placed, is completely closed on all sides, as will be noted from the drawing by the cylindrical portion of 52 and the ends thereof and by the barrel 22 so that the powdered material cannot escape, and the heat must necessarily be absorbed by the barrel 22. For supplying current to the heating` unit 17, there is arranged on the outerl casing 20' at the end,

contact rings 4:8 and bearing against these contact rings are brushes. The heating' unit -i-l-7 is connected through wires 51 with the outer rings i8, one of these wires supplying` current to the heating; unit and the other beinn,` the return wire.

To operate the furnace, the articles to be carburized for the purpose ol? ease hardening them, or be otherwiee subjected to heat treatment, are :introduced into the container 4.9, and the cover 27, 27X is closed. The current is turned on, the furnace set into rotation, and the heating` unit is cut into circuit` whereby the interior ot the container is raised to the requisite temperature.

l declare that what l claim is:-

l. A rotary furnace ot the rotary barrel type, formed. by the combination. ot a rotary chamber closed at one end. and having a central aperture at the other, a inutile or barrel concentrically mounted inside the said rotary chamber so that while both revolve together an annular space is left between them, an electric heater located in the said space, and insulated from the said rotary chamber, and a removable eontainer inserted closed end irst into the barrel through the said central aperture,` while the open end which is closed by a detachable cover is lett projecting.

2. A rotary furnace ot' the rotary barrel type formed by the combination of a rotary chamber closed at one end, and having a central aperture at the other, a muitle or barrel .concentrically mounted inside the said rotary chamber so that while both will revolve together, an annular space is left between them, a supplementary lire clay cylinder interposed in the annular space between the barrel and the outer chamber so as to 'term an inner annular chamber between it and the barrel, and an outer annular chamber between it and the outer chamber, an electric heating; unit composed oi" powdered material inserted in the inner annular chamber and insulating material inserted. in the outer one.

3. A rotary furnace of the rotary barrel type, 'termed by the combination ot a rotary chamber closed at one end and haring a central aperture at the other end, a inutile or barrel concentrically mounted inside of the said rotary chamber so that while both revolve together7 an annular space is lett between them, a heater located in said space, and a removable container inserted closed end first into the barrel through the aperture, and a removable cover closingthe open end oil" the container.

4l. A rotary furnace ot the rotary barrel type, toi-.ined ot a rotary chamber closed at one end and ha ring a central apei'ture at the other end, a removable container inserted closed end first into the aperture, an electric heater si1rroundingthe container, and a detachable cover closing;l the open end oi the coi'itainer.

ln witness whereof, l have hereunto signed my name this l9th day of April, 1920, in the presence ot two subscribing witnesses.

JGHANNES ROBERT CARL AUGUST,

llitnesses AUGUSTUS E. INGRAM, l. E. Nici-rotte.

Images