US1810801A - Method of removing gases from molten light-metals such as aluminum and its alloys - Google Patents

Description

June 16,1931.

METHOD OF REMOV and Patented June 16, 1931 1 UNITED STATES PATENT OFFICE WILHELM T0131, 01 LAUTAWERK/LAUSITZ, GERMANY METHOD REMOVING GASES FROM MOLTEN LIGHT-METALS SUCH AS ALUMINUM AND ITS ALLOYS Application filed July 29, 1929, Serial No.

My invention relates to a method of removinggases from molten .llght-metals such as aluminum and its alloys.

It is a known fact, that light-metals such as aluminum and aluminum-alloys cannot be cast in molds immediately upon the production thereof, for the reason that they contain comparatively considerable quantities of gases, which will be detrimental to the cast cases where a must be substantially free from blow-holes or ust in accordance with the amount of metal under treatment.

This method however does not give satisfactory results; even if the molten metal is allowed to stand for a very prolonged length of time, a perfect liberation of gases cannot be obtained in this way especially in those particular casting necessarily pores.

The chief object of the present invention is to provide a method which will overcome this difficulty.

" present invention, consists in agitating or moving the layer or volume of air located on top and above the molten metal and preferably causing the same to circulate without allowing any fresh air to mix therewith and without changing to a perceptible degree the temperature of the molten metal or the atmosphere pressure. I

In the accompanying drawing forming a part of this specification and showing .for purposes of exemplific'ation a preferred form of the apparatus for carrying out the invention the only figure is a View in vertical section of a melting furnace illustrating somewhat diagrammatically the means employed for. the present purpose.

In the drawing the character a designates the furnace provided with a charging door I) and a heating spiral a in a recess provided in With this object in view the 382,000, and in Germany .Tune 12, 1928.

the top structure of the furnace for the accommodation of the said spiral. In the upper portion of the furnace there is a circulating channel or passage 6 constituted by a vertical duct at one end of the furnace chamber, a similar duct at the .other end. thereof. and a horizontal tubular passage way interconnecting the said two ducts so as to form, together with the furnace chamber, a closed circuitous Way for the circulation of the air and gases enclosed in the furnace chamber. In the horizontal passage-Way preferably at a point midway between its two ends a fan f is inserted and arranged to be in connection with suitable means (not shown) for operation. 1

It will be seen that when the fan f is -caused to revolve the air and gases contained in the furnace chamber will circulate through the passage or channel 6 as indicated by the arrows. Obviously any other appropriate means may be employed for bringing about the circulation of the gaseous matter in the furnace, just as any other suitable air-agitating means such as a pump or the like may be substituted fointhe fan 7. What I claim is: v I

1. A method of freeing a bath of 'molten lightmetals such as aluminum and aluminum alloys from gases occluded therein, which consists in circulating the gases lo-' cated above the molten metal, without passing them through the metal and without substantially changing their volume and the temperature of the molten metal, and preventing the admission of fresh air to the furnace. 2. An apparatus for freeing a 'bath of molten light-metals such as aluminum and heating means in the said chamber, a con-' duit for the circulating gases connecting an exit-opening in the melting chamber to an inlet-opening of the same in this circulation conduit.

3; An apparatus for freeing a bath of molten light-metals such as aluminum and aluminum-alloys of gases occluded therein, comprising aclosedmelting furnace with a and a fan arranged melting chamber at the bottom thereof, an

electrical heating means in the said chamber and above the metal-bath, a conduit for the circulatin gases connecting an exit-opening 5 in the me ting chamber to an inlet-opening of the same and a fan arranged in the circulation conduit.

In testimony whereof I afiix my signature.

HELM TODT.

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