US67426A - Improved process of converting cast-iron into steel and malleable iron - Google Patents

Description

FLETCHER & BLANCHARD.

Refining lron.

Patented Aug. 6, 1867.

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UNITED STATES PATENT OFFICE.

FRIEND I. FLETCHER AND VIRGIL XV. BLANCHARD, OF BEIDPORT, VT.

IMPROVED PROCESS 0F CONVERTING CAST-IRON INTO STEEL AND MALLEABLE IRON.

Specification forming part of Letters Patent No. 67,1126, dated August G, ISG?.

To all whom. it' may concern Bc it known that we, FRIEND P. FLETCHER and VIRGIL W. BLANCHARD, of Bridport, State of Vermont, have discovered certain new and useful Improvements in the Method of Converting Iron into Steel; and we declare the following to be a full, true, and exact description of the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon.

Figure l is a perspective view of our invention.

Letter A represents the furnace, in which the iron ore is melted preparatory to being converted into steel or malleable iron. Leading from the hearth of this furnace is the trough B, through which the melted ore passes to the bath D. This trough is provided with a gate, (l, for the purpose of regulating the surplus metal. At the end of the trough there is a second gate, so as to control the iiow of metal into the bath and to prevent the ames from coming out. Leading off from the main channel E, just above the gate C, there is a second trough, E, which is much shallower than the large one. The molten metal pours from the hearth of the furnace A into the .main channel B, and flows down to the gate, where, if the gate is closed, it will accumulate and run oft' through the shallow channel. E. In practice, this accumulation is allowed to take place, so that a sufficient stream will iiow through this channel to carry ofi' the scoria or slae. After the accumulation of the metal has taken place the gate is partly raised, when the heaviest part flows under the gate into the bath, while the refuse or worthless part runs off through the channel E. These troughs should be slightly inclined downward, so that when the stream of metal has been once started it will be steady and continuous. Letter F represents an ordinary steam-boiler, in which the steam to be used in our process is generated. Immediately under the boiler F is the receiver G. This receiver is simply an air-chamber, which contains the `compressed air necessary to give uniformity to the blast. Leading from both the air-chamber G and boiler F to the bath are two pipes H and I, which are provided with suitable cock-stops, so that the currents ot' air and steam, or the mixture of both, can

be regulated at pleasure. These pipes are made to pass through the secondary furnace K on their way to the bath, where the steam or air, or a mixture of the two, can be heated toa degree approaching to decomposition before coming into contact with the stream of melted ore in the bath. At a convenient dis tance above the secondary bath the air and steam pipes are connected to each other by a short pipe, which is provided with a suitable valve, so that the air and steam can be mixed at pleasure. The waste heat of the furnacev may be so utilized as to impart the required degree of heat to these pipes, and in that case is equivalent to this secondary furnace. Before these two pipes pass into the bath they unite so as to form but one, and their contents can only escape into the bath through the small openings in the end of the trough B, over which the melted metal passes. Let ter D represents t-he bath, in which the melted ore is converted into steel or malleable iron. This bath may be constructed in the form as shown, or in any other one that may be convenient. Inside of the bath is placed the inclined plane L, as shown by red lilies, against which the metal is made to strike for the purpose of more efectually reducing it to globules, atoms, or particles. As the stream of melted ore is started from the furnace a jet of steam or air, or a mixture ot the two, moving with greater or less velocity, is brought into contact with it inside of the bath. The force of the current of air or steam, or a mixture of the two, reduces the molten metal to globules, particles, or atoms, while the heat of the same decomposes the steam or air into gaseous elements, thereby bringing each globule, particle, or atom of the melted metal into contact with it. Oxygen, 11ydro gen, or any other gaseous element, or any mixture of gaseous or volatile elements, may be used instead of steam, air, or the mixture of the two, according to the impurities required to be eliminated from the melted metal. IVe do not restrict ourselves to the use of steam or air, but claim the use of any gaseous or volatile element that the nature of the metal may require to effect the desired conversion or transformation. It will be particularly observed that it is by globularizing or atomizing the melted ore that a homogeneous product is obtained. By reducing themetal to globules or atoms the whole mass is brought into immediate contact with the gaseous elements contained within-the bath, and it is by this process onlyl that homogeneity is obtained. By means ofthe gate in the trough, leading from the hearth of the furnace to the bath, and the stop-cocks in the pipes leading throughthe secondary furnace, the size of the stream of melted ore, and the volume of the jet of steam or air, or a mixture of the two, may be regulated at pleasure. Thus, not only the amount ot' metal in the bath may be regulated, but the volume of gaseous element in the same, by means of which the elimination of the ilnpurities contained in the metal takes place.

l Hence, by increasing or diminishing the size ot' the stream of melted metal with a given volume to the jet of gaseous element or elements, or with a given size to the jet of gaseous elements, with a variable volume of melted metal, a greater or a less proportion of sulphur, phosphorus, or any other impurity in the metal for which a gaseous element within the bath may have achemical affinity, may be removed from the molten metal at pleasure. As the ore flows into the bath it is thrown against the inclined plane by the force of the j et, and becomes reduced to atoms or particles, which are reilected through the gaseous element contained in the bath. In the journey which the atoms take through the gaseous elements, coming in free and immediate contact with it, the impurities which the metal contains are eliminated or driven oli' by chemical affinity, leaving malleable iron. By

means of the pipe M, which is connected withV the other two, H and I, a secondary jet or jets of air, steam, or a mixture of the two, is introduced into the molted iron after it has been globularized. The force of this jet or jets, aided by the sudden expansion of the gaseous elements contained in the jets, consequent upon the intense heat of molten iron, completes the globularizing and atomizing of the ore. As soon as this process is accomplished the ore is then run out through the channel N into railroad-rails, gearing, or any other form del sired. Some ores requireair alone or steam alone to best effect the required conversion.

Te do not claim ebullition or boiling, but simply atomizing or globularizing, as above described. Neither do we claim the injection of the gaseous element or elements into or through a stream of molten iron, allowing such stream to preserve its continuity as a stream.

Having thus described our invention, what we claim, and desire to secure by Letters Patent is- 17. We claim dispersin g or reducing the molten metal to an atomic condition in the presence ofthe gaseous element or elements contained in the bath, substantially as and for the purpose specified.

2. We claim the forcible dispersion of a stream of molten metal into a globular or atomic condition when it comes in contact with a jet or jets of a gaseous element or elements, substantially as and for the purpose specified.

3. We claim the introduction of a secondary jet or jets of a gaseous element or elements into the bath above, below, or beyond the primary one, substantially as and for the purpose specified.

4. We claim the use of an inclined plane, or its equivalent, within the bath, in combination with sai/d bath, as and for the purpose specified.

5. We claim a secondary furnace, or its equivalent, for the purpose of heating the gaseous elements, substantially as and for the purpose specified. v

6. We vclaim a gate or valve in the main trough or channel, in combination with said trough and the shallow channel and bath, substantially as and for the purpose specified.

7. We claim the employment or use of the necessary valves in the pipes leading from the boiler and receiver to the bath, for the purpose of regulating the flow of gaseous element or elements into said bath, substantially as and for the purpose speciiied.

8. "We claim the use of any gaseous element or elements besides those contained in air or steam, used and applied substantially as and for the purpose specified.

In testimony that we claim the above as our own we hereby afix our signatures in the presence of two witnesses.

Witnesses H. HALE, J. L. HAMMOND, N. S. BENNETT.

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