US1691259A - Annealing furnace - Google Patents

Description

Nov. 13, 1928. 1,691,259

- K. TAMELE ANNEALING FURNACE Fiied Dec. 2, 1926 WITNESSES: INVENTOR 42w. Kar/ Ema/e.

' ATTORNEY Patented Nov. 13, 1928.

UNITED-STATES PATENT OFFICE.

KARL TLMELE, OF BERLIN-WILMERSDORF, GERMANY, ASSIQNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A'CORPORATION OF PENNSYLVANIA.

ANNEA ING FURNACE.

Application filed December 2, 1926, Serial No. 152,155, and in Germany December 5, 1925.

My invention relates to annealing furnaces and particularly to electrically heated brightannealing furnaces.

An object of my invention is to provide a simple and eiiicient bright-annealing furnace.

Another object of my invention is to provide means in a bright-annealing furnace for removing vapor from the furnace atmosphere.

Other objects of m invention will be ap- 0 parent from the disc osure.

It is customary, in bright-annealing furnaces, to till them with hydrogen in order to protect the material being annealed against oxidation. It has been found, in such furnaces, that a certain amount of steam is generated during the annealing period which oxidizes the annealed material during the cooling period. My invention is designed to prevent such oxidation by removing the 20 steam from the protective gas.

In practicing my invention, according to the manner herein disclosed, a furnace having a chamber adapted to receive material to be heat treated is provided. This chamber is connected by passages with a chamber that is cooled by suitable means. Since the furnace atmosphere is exposed to the cooling action of the cooling chamber, steam in the atmosphere is condensed. Means is provided to convey the condensate away. i

In the drawing, Fig; 1 is a somewhat diagrammatic sectional view of the furnace embodying my invention; and

Fig. 2 is a'similar sectional view of a fur nace embodying a modification of my invention.

Referrin to the drawing for a more detailed discl osure of my invention, the furnace shown in Fig. 1 comprises a casing having a refractory insulating portion 12 and an outside portion 14. lVithin the easing 10 is a chamber 15 that is adapted to receive material to be heat treated.

For the purpose of providing further insulation, an air chamber may be formed about the casing 10 by means of an auxiliary casing 16 that is provided with a suitable seal, such as an oil seal 17, at its top. A cover member 18 has its rim portion 19 immersed in the oil seal 17 and is spaced from the bottom thereof by means of suitable supports 20.

Suitable heating means is provided and,

as a convenient form of such heating means,

I have shown electric heating elements 22 that are positioned in the chamber 15 and are-se-' cured to the insulating portion 12. The heat ing elements 22 a e connected to a power source (not shown).

Below the furnace, cooling chambers 24 are placed, these cooling chambers being-con- 6Q nected to the chamber 15 by means of conduits 25. Conduits 26 are connected, at their upper ends, to the lower ends-of chambers 24, and, at their lower ends, to a conduit 28. The conduit 28 is provided with a valve 29 for permitting the escape of condensate, when desired, and for normally preventing the escape of hydrogen.

Suitable cooling means is provided to cool the cooling chambers 24. In the form of my invention shown in Fig. 1, such cooling means comprises the coils that are adapted to receive a cooling medium such 'as water.

Material 32, having been placed in the chamber 15 and the chamber having been 7 filled with hydrogen through a suitable opening (not shown), the opening is hermetically closed, the heating coils 22 are energized, and the furnace is heated tothe proper degree of temperature for the proper length of time 80 to perform the desired heat-treating operation.

At the end of the heating period the heating elements are de-energized, and the material 32 is allowed to cool. I During this period, if any steam is present in the protective gas, the material 32 to be treated will be oxidized. To prevent such oxidation, the

cooling chambers 24, above described, are provided.

When the heating elements 22 are de-energized, cooling medium is passed through the coils 30, and the cooling chambers 24 are thus cooled. Such cooling produces a contraction of the gas within the chambers 24 and a 95 condensation of any steam that may be therein. The contraction of the gas permits gas from the chamber 15 to flow into the cooling chambers 24, and any steam that may be present in such gas is likewise condensed. 1 The condensate will, of course, flow downwardly through the conduits 26 to the conduit 28 where it may be withdrawn at the proper time by opening the valve 29. .It will ing portion 40 that is surrounded by a casing 42. About the casing 42 and spaced therefrom, is an auxiliary casing 43, having a bottom'wall 44, for providing an insulating chamber about the furnace. An oil seal 45' and a cover member 46 are provided at the top of the auxiliary casing, the cover member 46 having its rim extending into the oil seal 45' and spaced therefrom by means of supports 47 The bottom wall 44 is provided with perforations 48 and is secured by welding or other convenient means to the upper wall 49 of a supporting member 50. The lower wall 51 of the member 50 is preferably made of refractory insulating materiah By welding the bottom wall 44 to wall 49 a hermetical seal at the bottom of the casing 43 is effected. A chamber 52, adapted to receive material to be heat treated, is provided within the casing 40. Electric heating elements 53 may be provided within the chamber 52, that are connected to a suitable source of power (not shown).

Beneath the casing 40 a plurality of cooling coils 54 are positioned. The cooling coils 54 rest on the bottom wall 44 of the casing 43.

The space 55 between the wall 44 and the bottom of the casing 40 is hereinafter called the cooling chamber. The cooling chamber 55 communicates with the chamber 52 by means of passages 56, and the cooling chamber 55, in turn, communicates, throu h the perforations 48, with conduits 57. he conduits 57 are connected to a conduit 58, which may have a valve 59 therein. Material 60 may be placed in the chamber 52 through any suitable opening (not shown).

The operation of the form of my invention shown in Fig. 2 is, in general, similar to the operation of the form of my invention shown in Fig. 1. However, in this form, the atmosphere of the furnace comes in direct contact with the cooling coils instead of being separated therefrom by the walls of a cooling chamber, as in the furnace shown in \Vhile I have shown the furnace as being electrically heated, it is, of course, obvious that other means might be employed to heat the furnace. It is also obvious that it is not necessary to position the cooling coils at the bottom of the furnace, as illustrated in the present disclosure.

While I have shown and described, for the .purpose of illustration, a particular form of my invention, it may, of course, be embodied in'other forms without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as m invention:

1. In a brig it-annealing furnace, in combination, a heat-insulated casing having a chamber therein, cooling means below the chamber for condensing the steam in the furnace atmosphere, and means for exposing the furnace atmosphere to the cooling astion of the coolin means.

2. In a bright-annealing furnace, in combination, a heat-insulated casing having a chamber therein, electric heating means in said chamber, cooling pipes positioned at the bottom of the furnace below said chamber for condensing vapor in the furnae atmosphere, means for exposing the furnace atmosphere to the cooling action of said cooling conduits, and means for withdrawing the condensate.

KARL TAMELE.

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