US1741411A - Electric furnace - Google Patents

Description

Dec. 31, 1929. J. R. Evt-:s 1,741,411

ELECTRIC FURNAGE Filed Jan. 20. 1928 2 Sheets-Sheet 1 w.. www. wl m mw mx 1 l I I.

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Dec. 31, 1929. J. R. EvEs ELECTRIC FURNAGE Filed Jan. 20, 1928 2 Sheets-Sheet 2 W. @NNI NW mw MNNER m .N

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llllillr NNN Patented lDec. 3l, 1929 UNITED STATES PATENT OFFICE JOSEPH R. EVES, OF BUFFALO, NEW ASSIGNOR TO lFALLS ELECTRIC FURNACE CORPORATION, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK ELECTRIC .'FU'RNACE Application led January 20, 1928.

This invention relates generally to electric furnaces but more particularly to that type including a platform for the material to be heat-treated which is movable into and out of 5 'the furnace.

One of its objects is to provide a simple and inexpensive furnace of this character having positive means for sealing the loadcarrying platform in place and'thereby prevent un- 0 'due loss of heat and afford a saving in the consumption of electric power.

A further obj ect of the invention is to provide a trackless furnace of this type which is efficient and economical in operation and which minimizes the expense of the load-carrying equipment used in connecting therewith.

A still further object is the provision of simple means for supporting the load-carry- Zoing platform in a position for effecting the admittance of an even distribution of air to the furnace chamber for the purpose of gradually cooling the charge.

In the accompanying drawings:

Figure 1 is a front elevation of an electric furnace embodying my invention. Figure 2 is a vertical longitudinal section thereof on line 2 2, Fig. 1. Figure 3 is a transverse section on line 3 3, Fig. 2. Figure 4 is a 0 `horizontal section of the furnace taken in the plane of line 1 -4, Fig. 2. Figure 5 is a transverse section, similar to Fig. 3, showing the work-carrying device in its elevated unsealed position. Figure 6 is a front end view of the Wheeled truck.

Similar characters of reference indicate corresponding parts throughout the several views.

In the preferred embodiment of the invention shown in the drawings, 10 indicates the heating chamber and 11 the furnace body which maybe constructed of any suitable refractory material. The heating chamber is closed on all sides with the exception ofits front side, which is open and adapted to be closed by a vertically-movable door 12 suspended from chains 13 and operated in any approved manner. Applied to the walls of the heating chamberare the resistor elements 14 which may likewise be'of any well known Serial No. 248,175.

construction. As shown in Figs. 2 and 3, the heating chamber is disposed above t-he fioor line to provide an air space or compartment 15 beneath it, and to this end the walls of the furnace. are supported on a metallic frame which may be composed of longitudinal and transverse Z-bars 16 attached to upright channel bars 17.

The bottom of the heating chamber is preferably in the form of a movable platform or work-carrying device 18 which is capable of being moved longitudinally into and out of a suspended position in the compartment 15 thru the open front end of the furnace and which is adapted to be moved vertically into and out of its operative position to effect an air tight, sealed bottom for said chamber or to permit the admission of a certain amount of air thereto for cooling the charge after its desired heat treatment has been completed. This platform is made of structural steel and insulating material and supported on legs 19. Any suitable means may be employed for moving the platform into and out of its opere ative position in the furnace, that shown in the drawings, by way of example, consisting of a well known type of wheeled truck 2O hav ing a vertically movable member 21 which functions to elevate the work-carrying platform.

This movable member may be actuated in any suitable manner, for example, by pinions 31 engaging corresponding racks 32 depending from such member, whereby upon turning the operating crank 33, the movable member is raised or lowered.

Extending around the side walls and rear Wall of the furnace adjacent to the compartment 15 is a sealing trough upon which the platform 18 is adapted to seat in its operative position and thereby form an air-tight seal Valong these walls to eliminate heat losses within the furnace. This trough is preferably made of channel bars 22 containing sand or like material and secured to the inner sides of the depending flanges 23 of the Z-bars 16. Depending from the sides and back of the platform 18 are sealing plates or aprons `211 which are adapted to enter the sand-filled channel bars in the operative position of the H5 portingthe platform in-a Partially elevated platform shown in Figs. 1, 2 and 3, and therey effectively seal the lower end of the fur nace chamber at its sides and back. For the purpose of sealing the lower front end of the furnace, the platform is provided across its front endf with a transverse trough 25 constructedofachannel bar containingsand and the vertically movable door 12 is adapted to engage said trough in its closed position, as seen in Fig. 2; As shown in Figs. 1 and 4, the trough-bar 25 on the platform extends laterally beyond the ends of the longitudinal trough-bars 22 on the furnace which latter are disposed below the plane-of the former, so that when the platform is in its operative positionthelower endof the furnace chamber is sealediaround its four sides.

In theuse of the apparatus thus far described, assuming the furnace door 12to be open, the platform 18- is loaded with its charge andthen supported on-the truck 2O andwheeledinfan-elevated position into the compartment 15 of the furnace, the elevating member 21v of thel truck being raised to such a height-asto allow the depending aprons 24 of theplatform toc-lear the sand troughs 22 of the furnace, For the purpose of guiding the platform intoits compartn'ient, longitudinal guide rails 26 may be provided which are attached to the upright channel bars 17 and are disposed below the furnace troughbars22: After thus beingmoved into the furnace compartment 15, the elevating member ofthe truck is lowered to bring the platform-aprons 24 into engagement with the sand-troughs applied tothel sides and rear end-of? the furnace, after which the door 12 is lowered to Abring its lower end into engagement, with the sand-filled trough 25 on the front end ofthe platform. W7 ith the plate form'properly set in a suspended position to effectually sealthe furnace chamber 10, the truck'20-can beremoved and be utilized for use in connection with other furnaces which may be ready for recharging or discharging of'ftheircontents. In removing-the platform, the furnace door is opened and the truclr is wheeled'under said platform to raise it clear of the sealing troughs, after which it is pulled out of the furnace on the truck and unloaded.

By providing a suspended load-carrying platform-and a sealing means of this character, the danger of losing sandfduring the insertion and removal ofthe platform into and out ofthe furnace is eliminated, thereby assuring at all times a positive and effective sealy against heat losses from the furnace chamber.

Ingorder to eect a gradual cooling of the charge after undergoing heattreatment, a

uniform distribution of air is adapted to be admittedaroundf'tlie four sealed sides of the platform 18. This is preferably accomplished by providing an adjustable means for supposition to break its sealed oint. The means shown in the drawings consists of` longitudinal base rails 27 disposed along opposite sides of the platform-compartment 15 of the furnace and attached at their front and rear ends to horizontally-foldable links. 281 pivotedtobase'plates 29. These base rails are adapted to be moved to a position for allowing the legs 19 of the platform to restthereon aiid'holdthe aprons 24' outoffsealingjengagement with the sand-troughs22, as sliown in Fig. 5. In seating the platform in'such position, it is first elevated the required distance by thetiering truck 20, after which the base rails are shifted under the legs to support they platform, the truck being then re,-

moved and usedy forl other duties.. This are;

rangement permits. of readily: breakingy the seal between the platform. and: the furnace and allows for the slow and even distribution-` of air thru all sidesof the heating'chamber:

This improved electric furnace provides for the efficient and economiehandling of'thematerials to be treated bye simple and inexpensive means which are soorganized andfarranged as to veffectually, seal the furnace against heat losses. while the materials are undergoing heattreatinent,.v and which provides for the gradualLcooling-of tliematerials by breaking such seal: andiadmittingfan even distribution` of air to the furnace chamber thru all sides thereof. construction eliminates. the use of; expensive car and track equipment nowemployed inelectric furnace installations and materially reduces the operating and maintenance costsv of such furnaces.

I claim as my invention.:

1. An electric furnace, comprising a'heating chamber open` at its bottom and having a door at its front end, a trough-shaped mein.-l ber containing a sealing materiali` extending'f around the sides and' rear end of.7 the furnace chamber adjacentitsbottom, a wheelless carrier for the material toibeheat-treated mov,-

able into and out ofthe furnace and formingr4 a closure for the bottomthereofl in its-oper` ative position, means for conveying'said carrier into and out of the furnace and-for; moving it vertically toward and fromthetroughshaped member, and aprons dependiiigffrom the sides and rear endof said wheellesscarrier for sealing engagement with the material in said trough-shaped member.

2. An electrio'furnace, comprisinga heating chamber open. at its bottom. and having,`

a door at its front end, a trough-shapedfmember containingvv a. sealing' material.. ext-ending around the sides andfrear end of the lfurnace chamber adjacent its fbottom,a wheelless carrier for the materialV to beheatetreated movable into and out ofy the furnaceand forming a closure for. operative position, means for"conveying@saidV carrier. in to and. out of the furnace, and for Furthermore, this the bottomA thereofvv initsmoving it vertically toward and from the trough-shaped member, aprons depending from the sides and rear end of said wheelless carrier for sealing engagement with the material in said trough-shaped member, and a second trough-shaped member containing a sealing material applied to the front end of said carrier and arranged to be engaged by the door in its closed position. 3. An electric furnace, comprising a heating chamber open at its bottom and having a door at its front end, a wheelless carrier for the material to be heat-treated movable into and out of the furnace and forming a closure for the bottom thereof, an upwardlyopening channel containing a sealing material extending around the sides and rear end of the furnace and disposed below its open bottom and below the top of said carrier, aprons depending from the sides and rear end of the carrier and engageable with the material in said channel for sealing the joint between said carrier and the furnace, and rests disposed in the bottom of the furnace and movable into and out of an operative position for supporting the carrier in a partially elevated position for breaking such sealed joint.

4. An electric furnace, comprising a heat- 3o ing chamber open at its bottom and having a door at its front end, a conveying device for the material to be heat-treated movable into and out of the furnace and forming a closure for the bottom thereof in its operative position, means for sealing the joint between said conveying device and the adjoining walls of the furnace, means for temporarily elevating said device for breaking said seal to admit air to the heating chamber for cooling the material undergoing heat-treatment, and means applied to the furnace for supporting the device' in its elevated position.

5. An electric furnace, comprising a heating chamber open at its bottom and having a door at its front end, a wheelless carrier for the material to be heat-treated movable into and out of the furnace and forming a closure for the bottom thereof, upwardlyopening channels containing a sealing material extending around the sides and rear of the furnace and disposed below the top of the carrier, aprons depending from the sides and rear end of the carrier and engageable with the material in said channel for sealing the joint between said carrier and the furnace, and supporting rails adjustably mounted at the sides of the furnace for sustaining the carrier in a position to break the seal between it and the channels.

JOSEPH R. EVES.

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