US1564437A - Process of making malleable-iron castings - Google Patents

Description

Dec. 3, 19 's. 1,564,437

. w. J. MILES, JR

PROCESS OF HAKING MALLEABLS IRON CASTIN GS Filod Jan. 10, 1920 Patented Dec. 8, 1925.

UNIT D STATES WILLIAM J. MILES, JR,

OF MIDDLETOWN, OHIO.

PROCESS OF MAKING MALLEABLE-IBON CASTINGS.

Application filed January 10, 1929.

To all whom it may concern Be it known that I, WILLIAM J. Minus, J12, a citizen of the United States residing at Middletown, in the county of Butler and State of Ohio, have invented a new and useful Process of i l faking hlalleablelron Castings, of which the following is a specification.

This invention relates to processes for the manufacture of malleable iron castings.

The object of the invention is to provide a process which will yield the highest quality of malleable iron at less cost and in less time than by other processes.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings Figure 1 is a perspective view showing a cupola and an air furnace, the latter being illustrated with its top removed;

Figure 2 is a sectional view showing one of the removable cover or roof sections of the air furnace in place on the walls thereof.

8 is a cupola, having a charging mouth 9 and a charging platform 10. This cupola is of well known construction used in all iron foundries and needs no further description. An air furnace 11 is built adjacent the cupola with the spout (not shown) of the latter leading directly into the air furnace. Figure 1 shows a single air furnace in connection with the cupola, but obviously there may be several air furnaces used with a single cupola.

The air furnace has a hearth 12 and an opening 13 which receives the spout of the cupola. This opening 13 is located well above the hearth and is shaped so that the molten iron falls in a comparatively fine stream as-it passes from the cupola to the hearth of the air furnace. A discharging vent 14 is provided on the opposite side of the hearth, by means of which the bath of metal may be run off when purified into ladles for the molding process. The air furnace has a fire chamber 18 at one end Serial No. 350,665.

and fines 16 at the other, which fines pass under the hearth and lead out to the stack 17. Passages 19, closed by doors, are provided in the walls of the air furnace whereby the bath of metal may be rabbled at intervals. The top of the air furnace is closed by a plurality of cover sections similar to that shown in Figure 2. When the lining is to berenewed or other repairs made, one or more of these cover sections are removed.

The manner in which the above-described apparatus is used in my process will now be described. a

Pig iron, along with a certain portion of sprue iron, malleable, steel scrap and the like, is charged into the cupola with the fuel in alternate layers. The blast through the tuyeres is then started, and the metal quickly melts. At short intervals the molten metal is allowed to pass from the cupola to the hearth of the air furnace which it strikes in a fine stream. The air reaching the metal in this fine stream largely removes the impurities left in the metal after the melting in the cupola. The intense heat radiating from the walls and roof of the air furnace enables the oxidation of the impurities in the molten metal to be brought about more speedily. From time to time the metal may be rabbled through the openings 19. When the metal is ready, it will be drawn off through the discharge vent- 1 into ladles and teemed into the molds.

By first melting the iron in the cupola I save fuel and oxidation, because iron is melted quicker in a cupola than in an air furnace, and since it melts quicker it does not have time to oxidize. A cupola of good efficiency will use one part of fuel to eight of metal; whereas the best air furnace practice employs one part of fuel to four of metal; thus there is a great advantage in melting iron in a cupola.

However, the contact of the metal and fuel in a cupola makes metal peculiarly liable to burning which gives rise to sluggish iron, castings full of pin holes and trouble in the anneal. So instead of depending upon the cupola to accomplish the removal of all the impurities, I pass the molten iron before it has had time to become burned, directly into an air furnace without coming in contactwith outside air in its passage. As the molten iron reaches the interior of the air furnace it falls in a fine stream which,

with the air striking it, brings about the elimination of the silicon, phosphorus and sulphur.

Ordinarily, an air furnace while yielding a product of a high degree of purity has the disadvantage of using twice as much fuel as a cupola does to meltthe same quantity of iron. In short, the cupola is eflicient for melting iron, the air furnace for purifying it. I combine the cupola and the air furnace into an apparatus which utilizes the cupola to initially melt the iron and the air furnace to purify the product to the degree which is so desirable. use little fuel because the iron being poured into it in a molten condition only needs sufficient heat to keep it molten and to eliminate the remaining few impurities. Thus a much shorter time is required in the air furnace for the final purification.-

It is within the province'of my invention to employ a plurality of air furnaces if necessary with a single cupola As is well known air furnaces, even though of small size, may have a high efliciency. Inasmuch as continuous melting with a cupola gives the best results, it'may be desirable to pour metal continuously from a-cupola and use several airfurnaces in connection therewith so that while one air furnace is being filled and a second one-is in the process of purifying its bath, a third may be in condition to discharge its metal.

The air furnace willlV hat is claimed is 1. The process of refining iron in the manufacture of malleable iron castings which includes melting the iron in a cupola, and running the iron in a fine stream from the cupola into an air furnace.

2. The process of refining iron in the mai'iufacture of malleable iron castings which comprises melting the impure iron and removing certain of the impurities in a cupola, causing the molten iron to run from the cupola directly upon the hearth of an air furnace strikingthe same in a fine stream, at the same time excluding the atmosphere from contact with said stream of molten iron.

3. The process of refining iron in the manufacture of n'ialleable iron -astings which consists in melting the impure iron and removing certain of the impurities in a cupola running the molten iron from the cupola into an air furnace in a fine stream, said stream being out of contact with the atn'iesphere while passing from the cupola to the air furnace and falling upon the hearth of the air furnace while played upon by air currents, and removing the rest cf the impurities in the metal bath in the air furnace.

in testimony that I claim the foregoing as my own I have hereto aflixed my signature.

lVl'LLIAM J. MILES, J 1:.

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