US2599158A - Cylindrical converter - Google Patents

Description

June 3, 1952 H. A. BRASSERT CYLINDRICAL CONVERTER 3 Sheets-Sheet l Filed Dec. 2, 1948 IIIIIIII Il Il Illlllllllll] lll H IH l llllllllllllllllllllll m w, al

vENToR HERMAN A. BRASSERT A ORNEY5 June 3, 1952 H. A. BRAssx-:RT

CYLINDRICAL. CONVERTER 3 SheetsSheet 2 Filed Dec. 2, 1948 FIGZ.

Patented June 3, 1952 UNITED TTES PATEN T GFFICE 2,599,158 CYLINDREJAL coNvERTR limitan A, massen, Washington, conm-,assigner to H. Al -Brassert -& Comp'anyyNew .York,Y., a corporationof Illinois Application .December 2, 1948, vserial No. 'ssii-'51a in converters for treating molten iront'o convertl it into steel. 4

For many years, converters used 'in 'thep'ro'ducf tion of steel have been essentially unchanged despite the fact that these prior'converters have been known to 'have certain inherent defects.

The bottom blow Bessemer converteriss'tl a large pear shaped chamber, as invented lbyesf semer, having a pouring nose at one end through which the iron -is charged and the steel is discharged by tilting the converter about trunnions which are perpendicular lto thel axis of thec'ha'n'- ber. The blowing airis introducedby means of tuyres in the bottom ofthe converter so that the air is forced upwardly through the charge thereby converting the carbon in the 'ironto carbon monoxide with the generation of heatby combustion of silicon and carbon, and them'ore or less complete vremoval of bothfroin 'the charge; Inasmuch as air which Vis normally used inblowing the charge consists 'largely of nitrogen, there 'is' a tendency for the nitrogen to Vbe Aabsorbed inthe melt. The amount fof nitrogenabsorbedwill'depend upon a number jo'f 'fruitore 'ire'. 'the deeper the bath, the higher the'pr'essur'e, the longer 'the passage of air through V'the molten metal, th'erno're nitrogen that is picked up bythe melt. This is objectionable since a relatively minute nitrogen content renders the Bessemer 'steel brittle Vand produces undesirable veffects in the iinalproduct. Moreover, a great dealof heat is lost bythe'burning of carbon monoxide to carbon dioxide lattne nose of the converter, forming the well known Bessemer name. This high carbon monoxide content is normal since, the 'amount of air is introduced into the Vbottom of the molten bath, Where, at the prevailing high temperatures, no CO2 can exist in the presence'of ycarbon and theree fore combustion is incomplete and-only to carbon monoxide. Due to vthe fact that the -heat available in the converter is rather limited.' lthe amount of scrap that ycan'be melted in the con;

verter is also limited. n Y

Another less Widely used type "of converter i`s the side blow type. In thisitype fconverteiytl blowing air is introduced through tuyeres near the surface of the charge. There' is much .lower nitrogen absorption, but this t-yp'e of' 'converter cannot handle a .large charge, fand moreover. "be cause the air is 'introduced `near' "thef'sur'face, a relatively greater blowing time fisV required to remove the impurities than with theconvene tional lbottom 'blow type.

litl has been suggested that -a conventional bottom blow type of `converter can :be used :in such a way that both a bottom and 4a side blow isjobtained'by -tilting the converter so that some 'of -the bottom tuyres are disposed `above the surface of fthe charge in the converter. This expedient is not Vavery practical, however, for v'the reason "that jthe'Lcha-rge must be kept ver-y small in norderthat a reasonable tilting movement of the 'converter 'will expose some of the bottom tuyeres above the 'level of the charge. Under thesecircumstance's, 'only a small charge canfbe treated "in the converter as compared with the charge when the converter is used in the normal Way.

tjis -cl'earth-at the prior types of pear shaped converters have left-considerable to be desired parti'clarly 'fromthestandpoint of producing a 'relativelyl nitrogen-'free' steel lat a hief-h production -'c'ap`acity.

An vobject of the presentinvention is to provide `Aaconverter Afor producing steel in which a veryfclose control Aof temperature, and treating timeV with resultant low nitrogen absorption may bel `obtained W'hile handling -a relatively large volunteer tne'lircn rorfconversion 'into steel.

Another objectief `the invention to provide a feonverterin 'which much larger quantities of scrap can beused in theY productionof the steel than with fthelprio'r types of converters and'wh'ich, at 'the Sametime. Vpermits the desirable close control of the'treatin'g conditions.

A-st'ill further object of 'the invention is to provide vva converter 'having the `'tuyres arranged therein in such away that the 'blowing of the charge lcan `bestopped at any time to V:permit samples to be taken and additions to -be made without any way :endangering `the blowing operationby clogging :of Athe tuyres.

Another object of the invention vis 4to provide water cooled 'elements in the converter lining to protect it against "-impinging Vslag and flames. Another object iste mount the tuyres a water cooled ffrarne so that they may be easily replaced and/or changed.

Other objects of the invention `-vvillbecome apparent Ifrom the fiollowi'ng 'description of Pa `typical form of converter embodying"r the'present'invene tion.

In accordance with the present invention, 1I have provided a 'converter which isi'in-Ltheform of a cylinder mounted for rotation about'itsraxis, the 'latter being disposed in a Sulbs'tantiallyhorizontalplane, so that the cylindrical converter can lie-rocked 'l'a'clzv --and nforth to permit v.tirre-'in'tr'foduction of a charge into the converter and to discharge the steel therefrom.

A particular feature of the converter is the provision of tuyres extending lengthwise of the converter, these tuyres being so positioned vthat they may be rocked into positions above or below the level of the charge in the c-onverter or so that they are disposed above and below the surface oi the charge in the converter. Preferably, such blowing tuyres are mounted along only one side of the converter so that when the converter is rocked into the charging and discharging positions, the tuyres will be disposed entirely aboveV the level of the charge thereby permitting samples to be withdrawn and also preventing the metal from clogging the tuyres if the blowing operation is discontinued during sample taking.

Another feature of the invention is the provision of a novel cooling arrangement for the tuyres so as to prevent them from being destroyed or damaged from the intense heat within the converter.

A converter of the type described generally above has numerous advantages, the principal one being the close control of the blowing operation. Thus, during the initial blowing operation, it is possible to dispose the tuyres so that they are completely or partially below the surface of the charge in the converter. When the tuyres are disposed completely below the surface, the blowing operation is similar to that with the conventional Bessemer converter. If part of the tuyres are disposed above the level and part below, the combined effects of side blowing and bottom blowing are obtained. Under-these conditions, there is a rapid conversion of the carbon to carbon monoxide in the charge and a very rapid burning of the carbon monoxide to carbon dioxide at the surface of the charge which results in the generation of greater heat, thereby permitting greater amounts of scrap to be introduced into and melted in the charge. vThe inclusion of large quantities of scrap greatly facilitates the production of steel and increases the rate of production.

Moreover, by blowing a part of the air above the surface, a much smaller amount of nitrogen is absorbed in the steel, for only a part of the blast is in intimate contact with the steel. In addition to the foregoing, the arrangement is such that the vamount of oxygen supplied to the charge may be closely controlled, and, if desired. oxygen may be added directly to the air thereby increasing the oxygen content of the blast to generate more heat and this enriched blast will also further reduce the tendency of the metal to absorb nitrogen.

For a better understanding of the present invention, reference may be had to the accompanying drawings, in which:

Fig. 1 is a view in side elevation and partly in longitudinal section of a typical form of converter embodying the present invention;

Fig. 2 is a view in cross section taken on line 2-2 of Fig. 1 with the converter shown in the blowing position;

Fig. 3 is a view in elevation of one of the tuyre assemblies of the converter;

Fig. 4 isa view in section taken on line #-4 of Fig. 3;

Fig. 5 is a view in section taken on line 5-5 of Fig. 4; and

Fig. 6 is a view in section taken on line 6-5 of Fig. 3.

Figs. 1 and 2 of the drawings illustrate a typical form of converter embodying the present invention which may be made in any desired size suitable for the purpose. Thus, such converters may range in size from 25 tons capacity or smaller to 100 or more tons if desired. The c-onverter ncludes a cylindrical metal shell ID which is provided with curved end portions and I2 also formed of steel or other similar metal, the entire shell being provided with a heat resistant lining I3 of brick or other suitable material. At about the mid-portion of the shell is provided the charging and discharging nose portion I4 of the converter which, as shown in Fig. 2 is tapered. The nose portion I4 may be formed of a conical metal shell I5 provided with a refractory lining I6, and, if desired, may be provided with a removable lip portion I1 which is joined to the remainder of the nose portion I4 by means of suitable interconnected flanges I8.

Near the op-posite ends of the shell ID are provided the tracks i9 and 20 which are generally sector or arcuate shape. Each of the tracks, for example track 20, may consist of an arcuate inner band member 2|, welded or otherwise secured to the shell IG, and an outer concentric bandmember 22 which is retained in spaced relation to the band 2| by means of a series of spacer plates 23 and 24 which form a rigid and strong supporting structure. The tracks IS'and 20 are mounted on antifriction supports. Each of these supports includes a plurality of rollers 25 which are rotatably mounted on shafts 28 extending between a pair of arcuate side plates 21 and 28 which form, in effect, races for the rollers. The rollers 25 are, in turn, supported upon the heavy base member 29 which, as shown in Figs. l and 2, haveV arcuate tracks 3G upon which the rollers 25 roll.

Therconverter maybe rocked around its axis by means of an arcuate rack 3| located at about the mid-portion of the shell I0, this rack engaging a gear 32 which is driven by means of a speed reducing mechanism 33 and an electric motor 34 or other equivalent device. rihe motor is preferably of the reversing type so that the converter can be rocked back and forth.

As best shown in Fig. 2, the converteris'provided with a bustle pipe 35 extending along and connected to one side of the shell Ii), this pipe communicating with a plurality of tuyres 3B which extend through the side of the converter, and in the position shown in Fig. 2, areV directed upwardly toward the surface of the charge C in the converter. The bustle pipe 35 is connected at its opposite ends to tubular members 31 kand 38 to which air or air and oxygen is supplied through suitable rotary couplings (not shown). The members 31 and 38 are connected tothe bustle pipe 35 by means of the radially extending pipes S9.. If desired, several such bustle pipes and sets of tuyres may be arranged around the converter. i

As evident from Fig. 2, the converter can be rotated into a position in which the nose portion I4 is disposed to'approximately a 30 angle from the horizontal plane in order toreceive acharge. Also, as evident from Fig. 2,V the converter can be rotated to bring the-nose I4 into a downwardly inclined position to discharge the molten steel from the converter. V

In the blowing position, which is shown in Fig. 2 the converter is rocked so that the nose-portion i4 is Vdisposed counterclockwisevfrom the vertical in order to dispose the tuyres either .below or above the surface of the charge or partly below and partly above as required. In this way, a controlled blowing can readily be'obtained to make the bestiuse of the heat avaiiame in the carbon and to reduce nitrogen ,absorptionto a minimum YInasmuch as the tuyreseare'subjectedzto lntense heat, provision is `made for coolingthese a tuyres as described hereinafter.

A'suitable tuyre arrangement and coolingeystem therefore is shown in Figs. 3 to 6. As illustrated in Fig. 3 each of the tuyre assemblies having the several tuyres -36 may include a generally hollow box-like member 40 having an arcuate frame-like front plate 4| which is adapted to overlie the lportions of the shell I adjacent an opening 42 through the wall of the converter. As many such openings may be provided as may be required to accommodate the several sets of tuyres 36. The shell I0 is provided with upper pairs of lugs 43-43 and lower pairs of lugs 44-44 which are received in notches 45--45 and 46-46, respectively, in the front plate 4I. Cross pins 41 extend through these lugs to retain the frame 46 in position.

The openings 42 in the walls of the converter converge inwardly on generally radial lines and receive snugly the hollow housing 41a which extends rearwardly from the front plate 4 I. As best shown in Figs. and 6, the housing 4la is generally rectangular in cross section. Also, as shown in Fig. 4, it has an upper hollow wall portion 41h and lower hollow wall portion 41o which are substantially coextensive in length with the thickness of the wall of the converter. and an open inner end portion 49.

The hollow center portion of the member 40 has a ller 50 of tuyre brick through which extend the parallel tuyres 36 referred to above. These passages are substantially perpendicular to the inner face 49 of the box and communicate with the bustle pipe 35 which is disposed on the outside of the shell.

The tuyres are cooled by introducing water into the tuyre box 40 around the brick filler 50. As shown in Figs. 3 and 4, water may be introduced through the opening 52 in the lower lefthand corner of the frame 4I so that it flows through the hollow wall portion 41e of the box upwardly through the side passages 54 and '56 in the hollow side walls 51 and 58, then into the hollow top portion 4lb and along the hollow side walls 51 and 58 to the discharge outlet 59 in the upper right hand corner of the frame 4I. Each of the hollow side walls 51 and 5B may be provided with a downwardly extending partition 60 so that the ywater follows the path shown generally in dotted lines in Fig. 4, thereby assuring circulation of water around the entire outside of the tuyre brick filler in the box. In order to avoid trapping of steam or air in front of the partition 60, it may be provided with a vent opening 6l through which the air or steam can escape to the water outlet 59.

The above-described tuyre construction has the advantage that cooling water may be circulated continuously around the tuyres so that destruction of the tuyres by overheating is to a large extent overcome. The water may be introduced into the openings 52 through a cooling water line 62 shown in Fig. 2 and discharged through a cooling water discharge line 63 extending lengthwise of the bustle pipe 35.

The tuyres can be attached to and detached from the converter to permit their repair or replacement. To facilitate removal of the tuyres. the front frame member 4| may be provided with the ears 66 and 61 on its opposite sides, as shown in Fig. .3, in which are mounted set screws 68 and s69 which may-be turned up-against thel shell ol' the converter to force "the tuyre box 4 0 out `ci? the opening 42. p

Water-cooled elements 40a, similar in construction to the above-described tuyre boxes 40, but imperforate, are inserted in the converter lining opposite the tuyres 36, as shown lin Fig. r2, in order to protect the lining against impinging slag and ilame.

The above-described converter permits ,a more precise control of the blowing conditions within the; converter, for as indicated above, the action of the blast on the charge may be changed from a bottom blow to a top or side blow operation, and, more particularly, a very closely controlled combined top and bottom blow can be produced by a suitably positioning the tuyres with the result that the amount of nitrogen absorbed in the charge can be held to the desired minimum while the amount of available heat for melting scrap and other purposes may be very substantially increased. Moreover, by arranging the converter horizontally, a very large charge in proportion to the size of the converter can be handled quickly and efficiently.

The apparatus may be provided with suitable controls whereby oxygen can be added to the blowing air and may be adjusted 'so that a predetermined proportion of added oxygen can be maintained in the blowing air once the control mechanism has been set for optimum operating conditions. In this way, it is possible to obtain a much closer control of the blowing operation than with the prior types of blowing devices in which `a high degreeI of skill by the operator is required. Moreover, the arrangement of the tuyres in the side of a rockable converter of this type permits freedom of sampling and freedom of -discharge of the blown charge with the blast cut off without danger of clogging the tuyres by freezing of the molten metal therein. Moreover. damage to the tuyres by high temperatures is largely overcome by the water cooling system provided in this converter. l

It will be understood that the converter is susceptible to considerable modification, and that, if desired, one or more rows of tuyres may be provided in the converter. Accordingly, the form of the converter disclosed herein should be considered as illustrative of the invention and not as limiting the lscope of the following claim.

I claim:

A converter for producing steel comprising a cylindrical chamber for receiving a charge of iron, a refractory lining in said chamber, means for supporting said chamber for rocking movement about its axis with the latter in a horizontal plane, a charging nose portion at about the mid-portion of said chamber, a wind box extending lengthwise of and fixed to the outside of said chamber, a row of tuyres -connected to said wind box for directing air into the chamber, said tuyres comprising a frame member having hollow walls deiining a space extending from the front to the back of the frame member, a tuyrebrick filling in said space having tuyre openings therethrough, and means for circulating cooling water through said hollow walls to cool said lling; a water cooled member opposite to said tuyres and adjacent to said nose portion to protect said lining against impinging slag and ame, and means for rocking said chamber between a position in which the tuyres are disposed entirely below the surface of the charge and the nose portion is directed upwardly, and a position in which the nose 7 is directed downwardly and the tuyres are en- Number tirely above the surface of the charge. 942.973

HERMAN A. BRASSERT. 1,097,907 Y 1,390,694 REFERENCES CITED 5 1,502,621 The following references are of record in the 2.079.372 le of this patent: 2,261,559'

UNITED STATES PATENTS Number Name Date 10 327,422 Witherow sept. 29, 1885 Numrgo 870,925 Bagga-ley Nov. 12, 1907 Name Date Peirce Dec. 14, 1909 Bernhard May 26, 1914 Frawley, Jr Sept. 13, 1921 Folkerts July 22, 1924 Quinn May 11, 1937 Osborn Nov. 4, 1941 FOREIGN PATENTS Country Date Great Britain Dec. 28, 1877

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