US1694684A - Annealing furnace - Google Patents

Description

DcQ-? 1928.

F. T. COPE ANNEALING FURNACE Filed Nov. 9, 1925 lllllllhlllm gwoento abbot nu, 4

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FRANK 'I'. COPE, 0F SALEM, OHIO, ASSIGNOB TO THE ELECTRICAL FURNACE COM- PANY, OF SALEM, OHIO, A CORPORATION OF OHIO.

ANNEALING FURNACE.

Application led November 9, 1925. Serial No. 67,811.

The invention relates to furnaces for annealing of metals which require cooling in the furnace atmosphere and is specially applicable for use in annealing copper, particularly copper wire.

Tt is customary, in annealing such materials, to place the articles in a furnace, and

- hold the furnace at the required temperature for the time necessary, after which the heat is cut off from the furnace and the articles are left in the furnace and permitted to slowly cool therein until the furnace temperature is lowered 'beneath the scaling temperature.

This necessitates considerable time during which the furnace is not available for use, it

sometimes requiring a full day to cool the furnace from the annealing temperature to a temperature which' will safely permit removal of the articles.

Thus it will be seen that such practice revuires considerable time and expense,.as each furnace is out of commission for the greater part of the time, as the cooling extends over a period many times the actual heating time.

The object of the present improvement is to provide a furnace adapted for annealing materials of the character mentioned, and having means for rapidly lowering the temperature of the furnace and material when the heat is shut ed, in order to considerably speed up the operation and reduce the cost of annealing; and to provide a lining for the furnace, having a lower thermal conductivity and heat storage capacity than re brick.

The above and ancillary objects may be attained by providing a furnace with heating means at one or more sides, the'material to be annealed being placed within the furnace and spaced from the heating means; a cooling apparatus, comprising pipes arranged to be interposed between the heating means and the material when the heat is cut oft, in order to quickly bring the furnace, and material, down belowr the scaling temperature of the material.

An embodiment of the invention is illustrated in the accompanying drawing, in which the view is a cross section of the improved furnace, the cooling apparatus being to' shown in the lowered or inoperative position, in full lines, and in the raised or operative position, in broken lines.

Similar numerals refer to corresponding parts throughout the drawings.

The furnace indicated generally at 1, may comprise the bottom wall 2 and side Walls 3, supported upon beams 4, which span the pit 5 formed in the foundation 6.

The inner lining of furnaces is usually great refractory properties `as fire brick, still Y have properties in this respect ample for the present purpose.

This material is considerably lighter than fire brick, owing to its cellular nature, which, of course, requires less heat to bring a given volume to a specified temperature than is the case with fire brick.

In addition the termal conduction through the material is considerably lower than lire brick due largely to the minute air spaces formed Within the material itself.

These walls may be surrounded by a sheet metal shell 7, and the open, upper end of the furnace may be arranged to be closed by means of the roof 8, formed of the same material as the bottom and side walls and reinforced by the metal frame 9, and having the depending anges 10, arranged to seat in the sand trough 1l, carried at the upper end of the furnace, in order to provide a sand seal between the furnace and roof.

For the purpose of illustration, electrical resistors 12 are shown attached to the side Walls of the furnace, yand similar resistors 13 may be provided upon the bottom wall thereof, although it should be understood that othr heating means for the furnace may be use A rack or basket 14 is'provided within the heating chamber 15, of the furnace, to receive the copper wire o`r other material to be annealed. This rack is spaced from the electric resistors, as shown in the drawing; but is so errang and located as to permit all of the heat radiated therefrom to be receilled by the material located within the rac |Ihe cooling apparatus is normally located within the pit 5, and mounted upon a structural frame 16, arranged to be raised and lowered by means of the cylinder 1T and piston rod 18, the Huid pipe 19 having a three way valve 20 therein.

rIhis cooling apparatus comprises an intake manifold Q1 and an exhaust manifold 22, superimposed thereon, an inlet pipe 23 communicating with the inlet manifold and extending upward through the outlet pipe 24, communicating with the exhaust manifold. The upper, open end of the inlet pipe 23 is spaced slightly from the upper closed end of the exhaust pipe 24.

Cold water or other cooling fluid may be admitted to the intake manifold, under pressure, and will rise to the top of the intake pipe 23 and then descend through the outlet pipe 24; to the exhaust manifold.

Any desired, or necessary, number of these intake and exhaust pipes may be connected to each pair of manifolds. The upper ends of the pipes E24 are normally extended into the channels 25, provided through the bottom wall Q, and the fire brick tiers 26.

In annealing copper wire or other material in the furnace, the articles to be annealed are placed within the rack or basket 1-1 and the current turned on to the resistors 12 and lil. `When the articles have been sufficiently hea ted the current is cut off and the valve 20 operated to raise the cooling mechanism, projecting the pipes into the heating chamber of the furnace, between the resistors 12 and the rack 14,

as indicated in broken lines in the drawing. The cold water or other cooling fluid is then circulated through the cooling apparatus, in the manner above described, and since these cooling pipes are interposed between the resistors and the material the temperature of the material will be quickly lowered te a point which will safely permit removal of the material from the furnace. In the event cooling gas is used in the pipes, it may not be desirable to remove the pipes from the .furnace during the heating operation.

It will be obvious'from the above description, and an inspection of the accompanying drawing, that with the improved furnace the complete annealing and cooling operations may be carried out in only a fraction of the time required by the usual practice,

where the heat is merely turned off in the furnace and the material allowed to slowly cool therein to the scaling temperature.

I claim:

1. An annealing furnace including a heating chamber, heating means at the sideof the heating chamber, means for supporting material spaced from the heating means, a coolingpipe between the heating means and material and means for circulating a cooling fluid through said pipe.

2. An annealing furnace including a heating chamber adapted to receive material, heating means for the heating chamber, a cooling pipe, means for circulating a coolingfluid through the pipe and means for inserting the cooling pipe into the heating chamber between the heating means and the material.

3. An annealing furnace including a heating chamber, heating means therefor, a cooling apparatus, including a pipe closed at one end, an inner open ended pipe therein, means for passing a cooling fluid through the inner pipe to lthe outer pipe, and means for inserting said cooling apparat-us into the heating chamber and withdrawing it therefrom.

11. An annealing furnace including a heating eliambeiyheating means therefor, a cooling apparatus including a pipe closed at one end, an inner open ended pipe therein, means for passing a cooling fluid through the inner pipe to the outer pipe, and means for interposing said cooling apparatus between the heating means and the material.

5. An annealing furnace including heating means, cooling means interposed between the heating means and the central portion of the furnace, and means for rendering either the heating means or cooling means inoperative during the operation of the other.

6. An annealing furnace including heating means and cooling means, and means for projecting the cooling means into the furnace between the heating means and the central portion of the furnace when it is desired to cool the same.

'i'. An annealing furnace, heating means therefor, cooling means, and means for projecting the cooling means into the furnace between the heating means and the central portion of the furnace when the Aheating means is rendered inoperative.

In testimony that I claiml the above, I have hereunto subscribed my name.

raamt r. corr.

CERTIFICATE 0F CRRECTION.

Patent No. 1,694,684. Granted December 11, 1928, to

FRANK T. COPE.

lt is hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as "The Electrical Furnace Company" whereas said name should have been written and printed as "The Electric Furnace Company", as Shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may `conform to the record of the case in the Patent Office# Signed andy sealed this 5th, day of' February, A. D. 1929.

` M. J. Moore, .(Sel) Acting Commissioner of Patents.

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