US1456865A - Terminal for electric furnaces - Google Patents

Description

May 29, 1923. 1,456,865

P.,H. BRACE TERMINAL FOR ELECTRIC FURNACES Filed April 21 1921 WITNESSES: INVENTOR yup M Pep/"Tel" H Brace Patented May 29, 1923.

UNITED STATES 1,456,865 PATENT, OFFICE.

PORTER H. IBRAGE, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC 8: MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TERMINAL ron ELECTRIC FURN CES.

Application filed April 21, 1921. Serial No. 463,366.

T all whom it may concern V Beit known that I, PORTER H. BRAoii, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented anew and useful Improvement in Terminals A for ElectricFurnaces, of which the followsuitable high-temperature-resisting material, 1

ing is a specification.

My invention relates to electric furnaces and particularly to electric-resistance furnaces, and it has for its object to provide new and improved. water cooled terminal members for the electrodes of resistance: furnaces.

In high-temperature furnaces of thetype disclosed in application Serial No. 454,776,

filedMarch 23, 1921, by G. M. Little and assigned to the 'IVestinghouse Electric & Mfg. (10., it is highly desirable to prevent the leakage of the heated gases, located in the upper part of the furnace chamber. through the wall past the electrode to prevent the admission of fresh air which would have an oxidizing effect upon the carbonaceous resistor and upon the electrode.

In practicing my invention, I provide a closed metallic expansion member connected between the water-cooled terminal mounted upon the end of the electrode and a stationary cooling collar surrounding the electrode intermediate its length. and suitably secured to the two members. I provide a substantially air tight joint between the watercooled terminal and the electrode, and as the closed metallic expansion member is suitably connected to the water-cooled terminal and to the cooling collar, it provides a means for trapping any heated vapors which may leak past the electrode.

. In the accompanying drawing, the single figure is a sectional view of an electric-resistance furnace embodying my invention.

The electric-resistance furnace 10 of the type described and illustrated in the hereinbefore mentioned application, comprises an outer metallic casing or framework 11 provided with suitable supporting members 12.

An outer lining 13 comprises a plurality of refractory bricks or blocks of any suitable heat-insulating material, located inside of the casing 11. A lining 14 comprises a plurality of refractory bricks or blocks of a the bricks being so spaced apart as to form a furnace chamber 15 of any suitable or desired dimensions and shape.

A heating means for the furnace comprises a plurality of carbonaceous elements '16 whichmay be of the type disclosed in the hereinbefore mentioned application. The elements 16 are held in their proper operative relation to each other and in position in the furnace by means of an electrode 17 which may be of substantially circular crosssection'. The electrode 17 is resiliently pressed againstthe, resistor, a graphitemember 18 being placed between the resistor and the inner end of the electrode 17.

The resilient compressing means comprise a threaded rod 19, a helical spring 20, a nut 2.1 and a washer 22.

i A water-cooled metallic contact, terminal 23 may be secured to-the electrode 17 at the outer end thereof by a threaded opening 24 in the member 23 and a cooperating threaded end portion 25 of the electrode 17. The resilient compressing means operatively engages the outer end of the contact terminal 23, an insulating member 26 being placed between the contact terminal and the expanded end of the threaded rod 19.

An auxiliary cooling means, comprising a water-cooled collar 27, is located in the outer portion of the wall of the furnace and surrounds the electrode 17, a suitable clearance being allowed between the collar 27 and the electrode 17. The collar 27 is fitted tightly into the lining 13, to prevent any heated gas leaking past its outer annular surface. I

The contact terminal 23 has a limited movement relatively to the collar 23 fixed in the front of the furnace body by reason of the expansion and contraction of the various parts of the furnace as it is heated and cooled during its cycles of operation.

A metallic expansion member 28 is provided, suitably secured to the outer surface of the member 27 and the inner surface of the member 23 to provide a substantially airtight connection therebetween. The member 28.1nay be made of a plurality. of dished members of relativelythin metal brazed or soldered together somewhat similar to a bellows, to form a resilient expansion member to permit of allowin for the variable dis tances between the co lar member 27 and the contact terminal 23.

In case any of the heated gases located in the upper portion of the furnace chamber 15 leak past the electrode 17 and the collar 27', they are prevented from escaping to the open air by the closed member 28, which thus operates as a trap for the heated gases which may leak outwardly along the electrode 17. As the Water-cooled contact terminal 23 is so mounted on the end of the electrode 17 as to be substantially gas tight, any heated gases trapped by the member 28 Will be effectively prevented from escaping into the open air.

It is, of course, apparent that the temperature of the electrode 17 is higher at the point Where it passes through the collar 27 than at its outer end here the contact terminal is mounted thereon. A transfer or" heat from the collar member 27 to therelatively cooler contact terminal 23 is efiectedvhy the member 28,' Which permits heat to flow therethrough from the collar member 27 to the contact terminal 23, thus assisting in effectively cooling the electrode 17 intermediate its length.

It may be noted that the device embodying my invention provides a resilient metal expansion member for connecting an inner water-cooled collar member and an outer Water-cooled contact terminal, effective both to assist in reducing the temperature of the collar member and to prevent escape of heated gases leaking past said collar.

Various modifications may be made in the device embodying my invention Without departing from the spirit and scope thereof, and I desire that only such limitations shall be placed thereon as are imposed by the prior art or are Specifically set forth in the appended claim.

I claim as my invention:

In an electric-resistance furnace, the comhination With a movable electrode and a stationary Water-cooled collar surrounding said electrode, of a movable Water-cooled terminal secured to one end of said electrode and an expan sible meta-l tubular member secured to said collar and said terminal for preventing the escape of a heated fluid leaking past said collar and for equalizing the temperatures of said collar and said termina In testimony whereof, I have hereunto subscribed my name this 11th day of April, 1921.

PORTER BRACE.

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