US2144230A

US2144230A - Method for melting metals

Info

Publication number: US2144230A
Authority: US
Publication date: 1939-01-17
Anticipated expiration: 1956-01-17

Description

Jan. 17, 1939.

J. D. RUSSELL METHODv FOR MELTING METALSA Filed Aug. 21, 1936 I NVENTOR ATTORN EY Patented 17, 1939 UNITED lSTATES PATENT OFFICE James Donald Russell, Anniston, Ala.

Application August 21, 1936, Serial No. 97,146

6 Claims.

My invention relates to a method for melting metals and more particularly concerns the melting of iron and steel for making cast iron suitable for use in a Bessemer converter, open-hearth furnace, or for casting in a foundry; and contemplates improvements in a method adapted to reduce the cost of manufacture, improve the quality of the product, and permit absolute control of the elements entering the finished product and removed from the charge prior to pouring.

Heretofore, the cupola furnace has been the most inexpensive means for melting iron and steel for producing cast iron; but, due to its construction and manner of operation, the quality' of the cast iron and the economy of operation is dependent upon so many factors that waste and ununiform products are common practice. In the operation of a cupola furnace, a blast pressure' which is too high or too low, or varied during the same run is uneconomical; and too much or too little coke produces cold iron, oxidized castings, and waste of iron. 'I'he size, quality, and sulphur content of the coke must also be taken into consideration if the proper operation and best product is to be attained. The high cost of maintenance of the cupola type of furnace is also an objectionable feature which has been overcome by employing the method and apparatus hereinafter set forth.

My invention further contemplates the provision of a furnace in which fuels other than coke may be employed effectively to melt the charge and in which the fuel does lnot have to be graded to a predetermined size.

lMy invention further contemplates the pro'- f vision of a furnace in which the height of the fuel bed is maintained at the position at which the oxygen of the blast is entirely consumed, the maximum of carbon dioxide and minimum of carbon monoxide formed, and maximum temperature attained.

Briefly, my invention comprises a cylindricalshaped furnace disposed at an angle to a horizontal plane and having a charging door at its upper end and an air blast nozzle at its lower when relatively small fuel is used. the furnace is air blast to blow downwardly upon the fuel. TheA fuel and metal are .charged 'into the upper end of the furnace and the furnace is revolved about its longitudinal axis causing the charge to move gradually towards the lower end of the furnace and into the combustion zone which is maintained at a high temperature by the air blast. By means of the method and apparatus set forth herein, it is possible to melt most if not all the metal prior to passage into the combustion zone and without bringing the metal into contact with the air blast; thereby preventing the destructive action of oxidizing gases from affecting the product, improving the product by decreasing the sulphur content and increasing the metalloids,

silicon, and manganese, and permitting the regulation of the carbon content.

My invention embodies other novel features, details of construction, and arrangement of parts which are hereinafter set forth in the specifica'- tion and claims and shown in the accompanying drawing.

Apparatus embodying features of my invention is illustrated in the accompanying drawing, wherein: y

Fig. l1 is a longitudinal sectional view of my improved furnace, showing the manner of operating same when'relatively large size fuel is employed to melt themetals;

Fig. 2 is a view similar to Fig. 1, showing the furnace arrangement when relatively small size fuel is used; and

Fig. 3 is a sectional view taken along the line III-III of Fig. 1. 4

Referring now to the drawing for a better understanding of my invention, I show a furnace Scomprising a cylindrical-shaped metal shell 6 provided with a charging opening 1 at one end thereof and an air blast nozzle il at the other end. The inner wall of the shell is covered with a suitable refractory lining 9, and a tap hole Il is formed at the nozzle end of the furnace.

A pair of circular bands I2 are secured to the shell for engagement with four rollers I3 which serve to rotate the furnace about its longitudinal axis. The rollers are journaled in bearing brackets i4 mounted on a tilting table I6, and the roller i3* is driven by means of the motor I1 provided with a driving sprocket I8 and connected to a driven sprocket I9, secured to the roller I3, by a driving chain 2|.

The tilting table I6 is pivotally mounted at 22 in bearings 23 formed on a base 24 and theangle ofthetablewithrespecttothebasemaybe,

readily changed by means of the turnbuckle 2l which is connected to the end of the table at 21 and to the adjacent end of the base at 28.

In the operation of the furnace when relatively large size fuel is employed to melt the metal, the charge 3| enters the furnace through the opening 1 and gradually moves towards the combustion zone 32, and assumes a formation as illustrated in Fig. 1. During the downward travel of the charge, it is tumbled by the rotation of the furnace and is heated causing the metal to change to a liquid state prior to its entrance into the combustion zone and to pass out of the furnace through the tap hole Il. 'It will thus be observed that the molten metal 33 is not subjected to the action of the oxidizing gases and that the fuel bed may readily be maintained at the proper height to entirely consume the oxygen of the blast and thereby attain the maximum eiliciency. The fuel ash is carried out of the furnace through the opening 1.

In Fig. 2, the furnace is illustrated as arranged to burn relatively small size fuel which would be too light and dusty to arrange as'shown in Fig. l, wherein the fuel is piled in front of the air blast nozzle; otherwise, the operation is the same.

It will thus be,seen that my improved method and apparatus for melting metals will facilitate operations which have heretofore been difcult to perform and uncertain as to results; which will produce cast iron of a better and more uniform grade than has heretofore been attained; and which will also greatly reduce the cost of manufacture.

While I have shown my invention in but one form, it is obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof; and I desire, therefore,

that only such limitations shall be placed thereupon as are imposed by the prior art.

I claim:

1. The method of melting metals which consists in moving a charge of metal and fuel laterally through a furnace and towards a combustion zone therein, and blowing a stream of air through the combustion zone.

2. The method of melting metals which consists in tumbling a charge of metal and fuel in a rotating furnace to move the charge laterally therethrough and towards a combustion zone therein.

3. 'I'he method of melting metals which consists in tumbling a charge of metal and fuel in a rotating furnace to move the charge laterally therethrough and towards a combustion zone therein, and blowing a stream of air through the combustion zone.

4. rl'he method of melting metals which consists in tumbling a charge of metal and fuel in a rotating furnace to move the charge laterally therethrough and towards a combustion zone therein, and blowing a stream of air through the fuel in the combustion zone and above the metal collected beneath the fuel.

5. A method according to claim 4 in which metal is liquefied prior to contact with the air stream passing through the combustion zone.

6. The method of melting metal in a rotating furnace which consists in forming a charge of metal and fuel into a substantially triangularshaped mass as viewed in vertical section taken longitudinally of the furnace, moving the charge laterally through the furnace and toward a combust'ion zone therein, and blowing a stream of air through the fuel in the combustion zone and above the metal collected beneath the fuel.

JAMES DONALD RUSSELL.