US1720055A - Apparatus for manufacturing iron and steel - Google Patents

Description

July 9, 1929. P. J. PEYRACHON APPARATUS FOR MANUFACTURING IRON AND STEEL Filed May 2, 1927 2 Sheets-Sheet l INVENTOR;

PPS- Eiuvvrd Attorney.

y 9, 1929- P. J. PEYRACHON 1.720.055

APPARATUS FOR MANUFACTURING IRON AND STEEL File May 1927 2 Sheets-Sheet 2 Flare 3585M! Peyrachon INVENTOR:

y WXA Attornoy Patented July 9, 1929.

UNITED STATES PATENT OFFICE.

PIERRE JOSEPH PEYBACHON, F LAI'ELGUERA, SPAIN.

APPARATUS FOR MANUFACTURING IRON AND STEEL.

Application fled Kay 8, 1827, Serial No. 188,085, and 1n I'ranaev July 18, 1928.

One of the chief disadvantages which has,

up to the present time, prevented rotary furnaces from being extensively used in the modern manufacturing of iron is the great wear 5 and tear on the lining of the lower section of the furnace, due to the high temperature to which this part of the apparatus is subjected and to the precarious cooling mea'ns employed. The use of pulverized carbon in the manufacture of open hearth steel, such as in the Siemens-Martin process, has .likewise not come into extensive use because of the rapid filling up of the regenerating, chambers by the fine dust raised by the cinder of thepulverized carbon.

The object of this invention is, in general, to overcome the disadvantages above enumeratcd.

To this end I provide the lining of my rotary furnace with a protecting screen, directly in contact with the rising flames of the furnace and extending around the greater portion of its circumference. The invention 1s equally applicable to both the stationarytype and tilting type'of furnace. Furthermore to further assure the cooling of the lining, a movable hollow ring kept entirely filled with water is provided. The rising gases are arranged topass out of the upper art of the foundation which receives the ower section of the rotary, furnace thus preventing theflames Irom contacting with the lining of the the lower section of the furnace.

The open hearth furnace I use may constitute but a single chamber for receiving the metal whether it be of the stationary type such as the Martin furnace or of the movable type such as the Wellmann furnace. I provide a dust chamber in communication with a rotary carburizing furnace connected to a gas producing apparatus which burns all traces of combustible material.

My furnace is capable of producing pigiron or a less carbonized metal without silicon or sulfur, which metal is very liquid and becomes very hot.

The annexed drawing taken with the specification, illustrates by way of example, an apparatus constructed after the principle of my invention. In" the drawing,

Fig. 1 is a view in elevation of the assembled apparatus, parts being shown in section;

Fig. 2 is a plan view of the apparatus;

3 is a section along line 3-3 of Fig. 2;

Flg. 4 is a section along line 4-4 of Fig. 3; Fig.-5 is a section of parts illustrated in F1g.'1 but drawn to a larger scale to more clearly illustrate the invention, and

Fig. 6 is a detail of certain parts of the ap aratus.

eferring to the drawing, A represents a cylindrical rotary reducing furnace, slightly inclined from the horizontal. This furnace may be of any well known type of rotary furnace and is furnished with an interior refractory lining carried by the metallic casing of the furnace and extendin the full length of the furnace as is well own in the art.

Fixed to the, lower extremity of furnace A is a ring A of cast iron or steel and which may be cylindrical but as here shown takes the form of a truncated cone. This ring is arranged to have water circulated through, it, cold water being admitted at the lowest portion and the hot water being drawn off at the top.

Ring A (Fig. 6) is closed by means of a cover a in the form of an annulus, cut from sheet iron or steel and bearing against appropriate. annular flanges 0, ring A. Member at is held in place by means of springs d placed at intervals along its circumference. Said springs are provided with rollers 2), which bear against a flange b fixed to the casing of furnace A and rotatable therewith, at one end and bear against cover a at the other end.

Ring A rojects into a metallic housing B which is iined with a refractory material. Within this lining are formed two vertical channels f, f, symmetrically spaced with respect to the vertical axis of housing B and two horizontal channels connecting said vertical channels with the upper portion of housing B.

A masonry arch g of refractory material is provided on the interior of member B and serves as a protecting screen for the lower end of furnace A. This arch may, if necessary, be cooled interiorly by a water jacket.

On the lower portion of housing B is formed a base which is cooled by a water spray, and opens into the smelting furnace C. The rotary furnace A is laced into communication with furnace by means of the opening it piercing the arch of the latter.

The smelting furnace C is of masonry and 0, carried by consists of a suitable refractory material held together by steel or iron plates. The upper portion of the furnace takes the shape of an inverted truncated cone and the lower portion that of a cylinder in which are lodged a plurality of interiorly cooled tuycrcs Said cylindrical portion is lined with a refractory material and constitutes the crucible of the furnace.

On the periphery of the crucible near the lower part are disposed a number of openings 0 which connect with the interiorof the furnace. Into each of these openings is inserted a carbon electrode a. The crucible is further provided with a tap p for drawing ofi the metal and a tap q for drawing off the slag. The hearth of the furnace is of masonry and of a refractory material.

D is a rotary carburizing furnace comprising an inclined cylinder furnished with a refractory lining similar to but shorter than furnace The extremities of the cylinder are provided with rings similar to ring A of furnace A. The extremities of furnace D are housed in casings F, F lined with a refractory material.

Housing F is furnished with an opening and a damper which connects with a pipe G leading to housing B. Housing F likewise is connected to an open hearth furnace L by means of pipe K which communicates with opening t in said housing.

H represents any suitable gas producing apparatus which is provided with a pipe u for injecting air and steam.

The open hearth furnace L comprises a melting chamber, one end of which connects with a dust chamber M while the other end is closed by a removable shield N which carries the cooled tuyeres a W is a tap for drawing off the metal and Z is a funnel like spout through which the furnace is charged with the molten metal from C.

A tuyere 7c is placed on housing F and a tuyere l is placed on housing B.

Helical screw conveyors m and a carry the materials to reducing furnace A and the combustible to the carburizing furnace D respectively.

The upper extremity of reducing furnace A is provided with a dust chamber 0 in which any large dust particles carried along by the gas coming from A are caught. The gas is then led to gas washers through pipe as in the usual manner. The lower portion of chamber 0 is closed by a water seal P.

The function of the apparatus is as follows:

Once the apparatus is started, ore mixed with the proper quantity of carbon is introduced into the rotary furnace A by means of conveyor m. The carbon may be in the form of lignite coal, peat, charcoal or wood. A small amount of flux is added, also through conveyor m. to give the proper consistency to the molten mass.

The materials introduced by the conveyor m become heated and the ore is reduced during their travel through furnace A. They attain. a temperature of from 1,000 to 1,100 degrees centigrade upon leaving furnace A.

The molten mass then tumbles to the bottom of funnel-shaped casing B and thence into the reducing furnace C through opento add through opening y provided in housing B for that purpose, a mixture of ore and limestone for the purpose of. oxidizing the excess carbon as well as the silicium coming from the silica of the gangue which will be reduced by the carbon at the moment fusion of the mixture takes place.

The quantity of ore to be added may be determined from the results of an analysis of a sample taken from the material issuing from furnace A. The introduction of the ore may be through the medium of an automatic apparatus if desired. The apparatus thus far described produces soft steel nearly free from silicium and of which the carbon content varies from 0.5% to 2%.

The metal on leaving furnace C may now be conveyed to open hearth furnace L into which it is introduced through the opening Z, where a further refining takes place and the necessary additions are made for obtaining the quality of steel desired. Through the charging doors of furnace L, scrap iron and other waste metal may be introduced as well as the refining materials.

When the refining is completed, the metal is drawn off into ingot moulds which are placed in a pit B, through tap w.

A liquid, solid or gaseous combustible is mixed with hot air and introduced into furnace L by means of tuyeres The mixture burns in the melting chamber of said furnace forming carbonic acid gas exclusively and gives to the fnrnace the necessary heat to accomplish the refining operation. The gases of combustion are led from the melting chamber into the dust chamber and thence into pipe K where they enter the lower extremit-y of furnace D through housing F In furnace D, the solid combustible material is introduced in its upper end by means of conveyor a. Under the influence of the heat content of the gases of combustion and their high temperature, the carbonic acid which they contain is reduced to carbonic oxide. The carbonic oxide and carbonic acid contentis at least 9 parts by Weight when the gas leaves furnace D.

The tuyere situated on housing F is used to inject a mixture of a solid, liquid or gaseous combustible and hot air carrying sufficient heat to effect the reduction of the carbonic acid thus maintaining the temperature of the gases between 1250 and 1300 degrees centigrade at the point of leaving the furnace.

The gases leaving furnace D are conducted by the pipes G to housing B where they enter at a temperature from 1150 to 1250 degrees centigrade. The gases here mix with those issuing from furnace C through channels f, pass into the furnace A and there supp y the necessaryamount of heat for producing the required temperature to bring about the chemical actions necessary for reducing the mass of ore contained in furnace A.

The gases on leaving furnace A pass into the dust chamber 0 and from there are led to gas washers by means of pipe line a; and are finally utilized in regenerators or other apparatus for the utilization of their energy content.

The combustible contained in furnace D burns when it contacts with the hot gases circulating therein. At the lower extremity of furnace D the residues of combustion enter the housing F and pass into the gas producer H by opening S where the residue of combustion accumulates. This residue which con sists of a mixture of cinders and coke is subjeeted to a current of air and steam issuing from pipe at. This air becomes heated in contacting the incandescent mass and burns all traces of coke. The cold cinders are drawn from the bottom of the apparatus I-I whenever necessary.

The tuyere Z situated on the front part of housing B may be used to inject either hot air or a mixture of hot air and a combustible for raising the temperature of furnace A at will.

The tuyeres z situated on the periphery of the cylindrical part of furnace C are employed at the time of starting the apparatus. They furnish air to the combustible supplied to furnace C. During the functioning of the apparatus they-may be used to supply gas from chamber O to the unmelted mass coming from B. This gas contains a certain amount of carbonic acid which reduces the excess carbon content of the mass and at the same time raises its temperature and carries the surplus heat of C to furnace A.

It is evident that many modifications might be made without departing from the scope of the invention as set forth in the appended claims. For example, open hearth furnace L might be replaced by an electric refining furnace. In this event furnace L could supply its gases directly by eliminating pipe K and utilizing tuyere It to supply continuously a mixture of hot air and combustible material. The apparatus otherwise would function as previously described.

The advantages derived from my invention may be summed up as follows:

The reduction to a minimum of the amount of solid combustible necessary to mix with the ore and consequently a minimum of slag and sulphur present in the molten contents of the furnace.

The utilization of half burned cinders for heating purposes as well as the burning of all sorts of combustible Waste material in the carbureting furnace down to the last particle of combustible matter.

The employment of solid pulverized combustible materials in the open hearth fur nace.

The obtaining of cast iron or a less can bonized metal at will in the smelting furnace, and

The utilization of the waste gases escaping from the open hearth furnace.

Having described my invention, what I claim is:

1. In ore reducin apparatus, the combination of a smelting furnace, a housing superimposed thereon, said housing being interiorly of refractory material with intercominunicating vertical and horizontal channels within said refractory material a rotary reducing furnace having one of its ends opening into said housing and a refractory flame bafile within the housing adjacent said end of the rotary reducing furnace.

2. In ore reducing apparatus, the combination of a smelting furnace, at hollsing superimposed thereon, said housing being interiorly of refractory material, a rotary reducing furnace having one of its ends opening into said housing, a water cooled easing about the said end of the rotary reducing furnace, a refractory flame baflie within the housing adjacent said end of the rotary reducing furnace, the refractory material of the housing having interior intercommunicating channels to guide the gases arising from the smelting furnace out of the path of material issuing from the rotary reducing furnace.

Signed at Bilbao. Spain, in the Province of Viscaya and State of Spain, this llth day of April. A. D. 1927.

PIERRE JOSEPH PEYRACHON.

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