US65333A - Ii the mawufaotuee of steel - Google Patents

Description

@latten igiene latat @fitta ARISTIDE BALTHAZARD B. BERARD, VOF PARIS, FRANCE.

' Law-.i 12mm N0. 65,333, ma .me 4,1867.

IMPROVEMENT IN THE MANUEAGTRE OE STEEL.

tite 5tlg-chale ruimt tu in their itunes hnelt mit linking putt nf ilgc same.

TO ALL TO WHOM THESE PRESENTS SHALL COME Be it known that I, Amsrrnn BAL'rImLinD Banani), Civil Engineer, Knight of the Legion of Honor, of j No. 57 Avenue Montaigne, Paris, in the Empire of France, have invented certain new and useful Improvements in thelanufacture of Steel and in the apparatus employed therefor; and that the following is a. full, clear, and exact description of` the principle or character which distinguishes it from all other things before known, and of the usual manner of making, modifying, and using the same.

My invention consists in an improved process and in improved apparatus for the manufacture of steel from cast iron. l

The object of my invention is to eliminate from cast iron as completely as possible foreign bodies which injure thel quality of the products, and by means which at the same timereduce the waste of iron to the lowest proportion, and to convert such cast iron into steel.

The principle upon which the improved process is founded consists in submitting cast iron after being liquefied, and by one and the same operation, to a series of successive oxidations and reductions.- The chief agents employed are air, water, steam, and reducing-gases, (such as hydrogen, carburctted hydrogen, oxide of carbon, and other like agentsQand carbon placed in contact by way of cementat-io'n.

To make my invention better understood, I will describe the same by reference to the accompanying drawings.

The fusing and converting-furnace is constructed of two sole-plates A and l5, Figure 1, so placed as to be easily separated from the furnace. These plates are provided with wheels resting on a plate, t and t', which can be wound up or down by a screw-jack; The circumference ofthe plate is lined with clay so as to form an airtight joint by the up-and-down pressure given to the movable sole-plate. Openings are made in the sole-plates for running off the metal and for the discharge of scorize. Rails are laid under the sole-platesvto facilitate their being changed and conveyed to a distance. These solc-plates are lined internally with brasque having a earbonaceous basis, and very thick. The mobility of the `sole-plates. serves to render their separation more easy during repairs. Between the two sole-plates are two-inclined planos, C and C', and a tire-bridge, D. The charge of cast iron in pieces is placed on the planes C and C', exceptwhere the iron' is supplied direct in a liquid state into the sole-plates. vThe cast iron gets heated, melts, and thc liquid metal falls on to the hollow solefplates A and B, the bottoms of which are previously highly heated.

The {ire-bridge D is constructed of two rows of {ire-bricks arranged so as to leave vent-holes for the passage of the liames. The open space between these two rows is filled with coke as pure as possible, or with charcoal which is introduced at the upper part. A cover with ajoint, as hereinbefore described, closes air-tight so as to prevent any introduction of external air. The gases, even those which are oxidizing inpassing through the fuel in the fire-bridge, become reducers, maintaining at the same time an elcvatedtemperature in the furnace.

The gas to be employed for heating the furnace isnow introduced into it by a series of annular blast pipe's, through the centre of which the hot air for the combustion is admitted. The quantity of vgas is regulated by means of two valves placed in the box, X, for the reeeptionof hot nir, and in each blast pipe by an obturator. The general regulation of the gas is effected by means of two valves connected by a balance lever and placed in l the box Y. They are worked internally by a crank-arm, Z, so that when one of the two opens the other closes. similar series of blast pipes is placed at each extremity of the furnace which act alternately. The number of pipes may vary, but I have found iive on each side to answer well.

Abovethe fire-brick pipes for conducting the gases and air into the furnace are placed the lues E EE E', which carry back the products of combustion into the chimney. At the point where the iues meet under the chimney a valve is set, which, while it opens a communication between one of the l'ues and the chimney, closes the communication between the chimney and the other flue; The heat liberated in the ilues and in the i chimney may be utilized for heating the air or for the production of the steam required.

Doors are made for working the furnace, both for feeding in the east iron and for working it 0n the Sole-plates. They are kept closed during the operation, or are only opened for taking out samples. They should be closed as air-tight as possible. Holes are besides made in each sole-plate for running oli` the products and for discharging the scorize on the surface. Other inclined openings FFF FH are made for the introduction of the blast pipes to act on or in the bath of cast iron. Two of the blast pipes enter the openings F F, and are in communication with the air, or het air and steam, and two others enter through openings F F, and are in communication with the purified gas hereinafter referred to. They are made of refractory or of an unfnsiblc material, and pierced at their lower extremities with several holes in order to divide the current and multiply the points of Contact. l l

The above-stated arrangements being made the operation is carried out asfollows:

The furnace is previously heated by means of combustible gases and hot air introduced by the series of annular blast pipes liereinbefore referred to. The current of gases is alternately made to pass from the soleplate A towards the sole-plate B, or reciprocally by turning on one side or the other the valve in the chimney, andby opening or closing the taps or valves correspnding with the air or gas. When .the furnace has reached the required temperature, the charging of the cast iron is effected on the inclined planes C and C', and it soon enters into fusion and runs into the hollow sole-plates. I then proceed tothe operations properly called purification and decarburation. For that purpose, after directing the current of the gases from the sole-plate A towards the Sole-plate B, for instance, I introduce through thc corresponding box the plunging blast pipe F in the solc-plate A, and set in action the hot air and steam, or ordinarysair alone, but in either case at a higher pressure than that necessary to overcome the resistance of the column of liquid cast iron. The pressure is given before the immersion of the extremity of the blast pipe. Thisv current in passing through the bath of cast iron produces a considerable bnbblingwhich facilitates the reaction ofthese fluids on the liquid metal. The action is oxidizing, and acts on all the bodies forming the complex alloy of the cast iron, at the same time producing a great elevation of temperature. Fixed and volatile oxides areformed; the latter escape through the chimney. The atmosphere of the sole-plate A is also oxidizing, and the drops of cast iron thrown olf will cross -it and fall back into the bath after undergoing the action of the medium through which they have passed. But the oxidizing gases of the sole-plate A, before arriving at the sole-plate B, Awill have to pass through the bed of incandescent fuel placed on the'separating fire-bridge D. The free oxygen'will be absorbed so that the gases will be reducers on their arrival on the'sole-plate B: Oxide of carbon and more or less carburetted hydrogen will be formed. The action on the solo-plate B will therefore be reduotive while it is oxidizing on the sole-plate A. This conversion would have the effect of lowering the temperature on the reducing sole-plate if the gases had not alreadyv acquired a very high temperature-caused by the period of oxidation; there is, therefore, a reaction of temperature from the oxidizing sole-plate on tothe reducing solc-plate,`which continually maintains on the two plates a considerable heat, which is an essential condition.

To increase the reducing power on the sole-plate B, I inject at the same time in the metallic bath,.by means of a plunging blast pipe, F, similar to the one hcrcinbeforc described for air, which is introduced through ythe adjacent box, a current of reducing gas at a suliiciently high pressure, such as oxide of carbon, or more or less carburetted hydrogen, previously purified with care. After these reactions have taken place during a certain time, the current is reversed by a movement of the valve intercepting or leaving open the communication with the chimney, thus changing the direction of admission of the air and heating gases intovthe furnace.v I then withdraw from the sole-plate A the air-blast pipe F, and introduce into the bath the gasfblast pipe F. Ido the same on the sole-plate B by withdrawing thevgas-blast pipe F, and introducing-the air-blast pipe Fl. I operate in the same way withthe oxidizing current on the sole-plate B, and I\react by reduction on the soleplate A.

The carbon of the cast iron burned by thev oxidizing current is restored in a certain proportion by theV current of the sole-plate by-way of cenientation by contact, and also by the oxide of carbon producing the bubbling. Some charcoal powder may at the same time be injected. It' the carbon were not restored in a certain proportion to the cast iron, the latter would pass too rapidly into the state of steel or iron, without sani-- cient time being allowed to expel the hurtful foreign bodies if they a-re in too large a quantity.

The reduction as well as the oxidation facilitates the elimination of the mctaloids in combination;l for hydrogen forms, equally with sulphur and phosphorus, gaseous compounds which escape by volatilization. But at the same time oxide of iron in the nascent stateis promptly reduced to a metallic state and enters into solution in the'bath, thereby reducing the waste. vByA this series of oxidations and reductions, to be repeated as often as the 'degree of impurity of the cast iron to be treated requires it, cast iron the most charged with injurious bodies can, be purified.

The last stage of the operation is more specially adapted for the deearburation by more specially setting in action the oxidizing current. The'cast iron being brought to the required degree of purity and decarburation, which is ascertained by taking samples, and after running olf the scori when necessary, I proceed to the running oil' the metal by unstopping the holes made for that purpose in the movable sole-plates. The molten steel then runs into the ingot moulds suitably arranged.

To obtain a certain quality of steel in the last stage of the operationI introduce scrap iron which has been previously heated onthe inclined planos C and C', and which is ldropped in the bath of cast iron.

When the' sole-plate needs repairs, and more particularly when the brasque requires renewing, the sole-plate is lowered by means of the screw-jack placed under the support plate, and substitute another sole-plate for it.

Having new described my invention, and the manner of putting the same into practice, I wish it to be understood that what I claim, is

1. The peculiar arrangement or construction of a rcverberatory furnace with double movable sole-plate, as hereinbeforc described, and shown in Figures 1, 2, and 3 of the accompanying drawings.

2. The interposition of a bed of fuel in the current of the gas, as hereinbcfore described.

3. The mode of :notion of the gas, of the steam, und of the nir, on or in the interior of the metallic bath, in the manner hereinbefore described. I

4. The arrangements a-boi'e described for causing the scori to aeton the metal for eliminating the phospl'ierus :md other injurious foreign metiers therefrom, as hereinbefore desoribedi 5, The reaction of lient from the oxidizing sole-plate on the reducing sole-plait, ns hereinbefore described.

6 The `arrangements for operating :it will by way of oxidation and reduction successively for purifying)lr cust iron, and for its reduction into steel er iron.

In testimony whereof I, the said RIS'HDE DALTHAZARD BRARD, have hereunto set my hnnd und :rilixed my .seal this 11th (lay of July, in the yea-r of our Lord one thousand eight hundred and sixty-six.

A. B. RENARD. Witnesses: v

II. H. DUFREN, RICHARD GM

Images