US1693388A - Heat-treatment apparatus - Google Patents

Description

NUM 27, 1928.

- 4HEAT TREATMENT APPARATUS Filed Jupe 1l, 1.927

Unir

rica.

GOTTLIEB KELLER. OF BRUGG, SWITZERLAND, ASSIGOR T AKTIENGESELLSCHAFT BROWN BOVERI & CIE., 0F BADEN, SWITZERLAND, A CORPORATION- 0F SWITZER- LAN D.

HEAT-TREATMENT APPARATUS.

Application filed June 11, 1927, Serial No 198,092, and in Germany'une 25, 1926.

This invention relates to heat treatment apparatus, particularly to apparatus for the heat. treatment of coils of wire for annealing or thek like. f e |The general object of the invention is the provision of apparatus which will be eHealtive to obtain rapid and uniform heat treatment of wire in coils.

Another object is the provision of such apparatus which will be ett'ective to prevent excessive oxidation of the wire during the treatment.

Another object is the provision of apparatus having the characteristics above specified which is simple in construction and in operation and facilitates charging and discharging of the treating furnace.

Another object is the provision of such apparatus particularly adapted for heating by electricity. i

Other and further objects will be pointed out or indicated hereinafter, or will be apparent to one skilled in theiart upon an understanding of the invention or its-employment in practice.

ln the drawing forming a part of this speci-4 lication, I illustrate one embodiment of the invention, but it is to be understood that it may take other structural forms, without departing from the scope of the appended claim.

In the drawing, the figure is an illustration in the nature of a sectional elevation of a heat treatment furnace.

Experience has shown that the time required for the heat-treatment of wire in coils cannot be reduced below a certain limit, even by increasing the amount of heat applied; The reason for this is the poor heat-transmit- 40 ting properties of the coils of wire. If the amount of heat applied is greater than the capacity of the coils for its transferenoe,then the result is an excessive heating of the wire in the outer layers of the coils, without any appreciable shortening of the time required for complete heat treatment of the coils.

According to the present invention, the transfer and equalization of heat among different parts of the coils is accelerated by employing solid metal discs at definite intervals .between the coils, which discs are made-of good heat-conducting material and present heat transfer surfaces distributed in association with different portions of the coils. As

15 of the receptacle 12, for introduction and circulation of an inertigas into the receptacle 12 to provide a non-oxidizing atmosphere about the coils of wire during the heat-treatment.y Heat distributing members 17, of good heat conductivity, are distributed at approximately uniform intervals Within the receptacle y12, and are arranged in contact with the walls thereof. As shown these are in the fdrm of discssupported on suitable brackets 18 on the wall of the receptacle at equal vertical distances, and as so dis osed are adapted to support the several coils (E, of wire. These heat-distributing members are arranged so as to afford circulation of the inert gas into all of the compartments between them.

In the treatment of the wire, the temperature within fthe refractory chamber is raised to the proper degree by the heat from the resistance elements 11, and this heat is transmitted through the walls of the receptacle 12 and through the heatdistributing members 4,

17 in such fashion as to beapproximately uniform all around the various coils. Thus the heat is distributed through the wire with increased rapidity and uniformity, and the time requisite for the heating of the wire to a desired temperature is thereby appreciably reduced. The invention is not confined in its applicationlto arrangements employing the interior gas-confining receptacle as illustrated 1n the example given, as the heat-distributing members may be arranged between coils or wire placed directly in the furnace chamber.

What I claim is:

In heat-treatment apparatus, an open-- ended receptacle uprightly disposed with its open end uppermost, means providing a closure for said end, material-supporting shelves of heat-conductive material disposed in and extending transversely of said receptacle and being supported in heat-conductive engagement with the walls thereof and for removal from said receptacle by way of said open end and in spaced relationshipwith respect to each other tovprovide superimposed heating chambers in said receptacle, the shelves separating adjacent heating chambers being provided with openings providing communication between such chambers, and means common with respect to said chambers and operable to provide for admission of a non-oxidiz- ,ass

ing atmospherento oneo said chambers and for the iow'of such atmosphere from said chamber intov the remaining chambers by Way'of said commnicating openings.

In testimony whereof I have hereunto subscribed my name this 27 dag' of May, A. D.

Q1927, at Zurich, vSwitzerlan GOTTLIEB ICELLER.

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