Imágenes de páginas

* 412

purposes of my present invention may be con- some independent equalization of the com. veyed by a gutter in a fluid state direct from position of each ladle or of the ladles of the smelting furnace where it has been ob- each group, but it affords no further advantained from the ore," without the expense tage, and in fact would not obviate the difand delay incident to the intermediate cupo ficulties of direct metal working. It does la process, practical experience, in this not enable the converter manager to foretell country at least, showed that the refini the character of each charge from the char. of iron without first casting it into pigs, se acter of the preceding charge, and would lecting or mixing the pigs, and remelting therefore entail the uncertainties of operathem, was attended with such expense that tion and the irregularity of the product the entire abandonment of the practice was which the Jones method avoids." seriously considered. The difficulty was in It had long been an object of manufacturthe material variations between different ers that steel should be made directly from portions of the same cast, and even differ- the molten metal, as it comes from the blast mo ent parts of the same pig, -an irregularity furnaces, without having to pass through which was increased when the metal was the intermediate.or cupola process, which drawn from several furnaces. There was involved the casting of the furnace metal added to this frequent changes in the char. into pigs. These, after becoming cold, were acter and composition of the ore, coke, and assorted, broken up, recharged and remelted limestone flux with which the furnace was in a cupola furnace, and then placed in a charged. The consequence was that the converter for conversion into steel. By this nonuniform chemical composition of the cupola process a product, practically uni. metal from the molten blast furnaces yield form in character and suitable for further ed products of steel, such as rails and treatment in the converters, was secured, beams, which were not only irregular chemi. but at the expense (more than 60 cents per cally, but of irregular and uncertain final ton) of rehandling and remelting the iron condition,-some sound, others of imperfect as it came from the blast furnaces, in cupostrength and full of flaws.

las, and the contamination of the metal These irregularities were in a measure with sulphur evolved from the coke in the obviated, not only by a careful selection of process of remelting. The obstacles con. a pigs beforehand, but by the necessity of nected with this method and the difficulties

employing upon receiving ladles or reservoirs attendant upon the use of the direct process into which the product of one or more cupo- are thus comprehensively set forth by Mr. la furnaces was drawn off into such reser. Julian Kennedy, one of the experts : voirs, which were made large enough to "Ever since the invention of the Bessemer hold the product of two or three furnaces, process it has been well recognized that and from which the molten metal was with great economics could be attained by transdrawn into the converters. Had the ferring the molten metal from the blast fur. amount required for the converters in each nace to the converter without allowing it case been the exact product of one or more to solidify. Until within a few years, howcupolas, no reservoirs would have been nec- ever, this direct process, as it has been essary, but as the demand was variable, a called, has not been generally used. It is storage of molten metal was required to re easy to see why this was the case. The tain the product of one or more cupolas, un. Nuctuation in the chemical composition of til it was required for the converters. Of the metal from the blast furnace was too course, as the product of two or more fur- great to allow that degree of uniformity of naces was drawn off into these receiving la product in the Bessemer steel produced dles, there would be some intermixing of from it which is absolutely necessary in the those products, although the receiving la case of steel rails, for example, which must dles do not appear to have been used for be as reliable as human skill can make that purpose, the operators relying more them, and where no reasonable expense can particularly upon the careful selection of be spared to make them perfectly safe and pigs beforehand, to obtain the requisite uni- trustworthy. A very few broken rails in a formity for conversion into steel. The la track, with the damage to property and hudles being open at the top, the molten metal man life which this might cause, would far could not long be retained in them, and in more than offset any possible saving in a the best practice it was so arranged that year's work, due to the use of the direct the withdrawals from the reservoir were process. For this reason the practice, until made every few minutes, and without re- within comparatively recent years, has been gard to the amount left in the reservoir to cast the metal in pigs, then to analyze after each withdrawal. It will be borne in it and reject any portion not closely approx: mind that the object in either case, whether imating a rigid specification in its chemical by direct or indirect process, is to obtain, composition, and to select, mix, and then as far as possible, a uniform product of melt the approved metal in cupola furnaces. iron for the converter.

By this means very great uniformity of “These results,” said one of the witnesses chemical composition of the remelted metal (Kennedy), speaking of the process used can be obtained, and good and reliable steel before that of Jones, "are not obtained by made from it with regularity and certainthe practice of taking metal from two blast | ty." furnaces by running a train of ladles in . Speaking of a time when the direct profront of them and tapping into each ladle cess (before that of Jones) had been in use half a charge and following it from a second for several years he said: furnace. By such practice, of course, there is "After studying the results which had

.414 911

been obtained at the Edgar Thomson works received and mixed with the molten metal and elsewhere in the use of the direct pro- in the dominant pool, they were, when discess, I consulted with Mr. James Gayley, charged from the reservoir, approximately, and we agreed that in the building of a new though not perfectly, uniform, the original works it would not be profitable to use di- variations having been lost in their mixrect metal, but that, on the contrary, the dis- ture with the dominant pool. “It is thereadvantages resulting from the irregularity fore plain,” says the district judge in his in the product were so great that it would opinion, “that with a mixer thus operated, be better to go to the expense of building it is possible to have wide variations in the and using, cupola furnaces. We did not composition of the blast furnace metal then perceive any means adequate to over charges added, and at the same time the come these disadvantages."

successive withdrawals for the Bessemer The difficulties connected with the prior converter show quite small and gradual devices are also stated in an article by Mr. changes of composition. The heat of the Holley, published in 1877, from which we detained mass is affected by the incoming extract the following paragraph:

charges just from the blast furnace, but “Third. The embarrassing feature of the the heat of such addition, whether relative direct process is the irregularity in the heat ly high or low, must mingle with, be modi.

that is to say, in the silicon of the fied by, and average with, the heat of the charges — resulting in the large amount of larger and dominating mass.” It is not scrap due to too little of this element, and insisted that this method gave absolutely in the increased number of second-quality uniform results, "nor," says the witness rails due to too much of it; while in France, Fry, "did the inventor, as I understood where 3 to 5 per cent of manganese is the him, comprehend such, but, on the con. heating ingredient, there may always be an trary, he recognized the practical impossi. excess of this latter element without injur. bility of rendering uniform a continuous ing the quality of the steel, although the supply of metal, and desired only to reduce variation of heat is here, also, a serious the abrupt changes of the several portions difficulty. In other words, it has not yet added to the gradual changes of the por. been practicable to work the blast furnace tions withdrawn, and this is what he with sufficient regularity to realize approx. worked out from his invention in a thor. imately the theoretical advantages of the oughly practical way." direct process."

While the patent in suit is for a process, “Fourth. The obvious remedy is to mix a and not for a mechanism, the process will number of blast-furnace charges, so as to be the more easily understood by a refer. reduce the irregularity to a minimum. Two ence to the apparatus above reproduced, systems of doing this are on the eve of trial: which consists of a reservoir, or closed reThe one is simply mixing so few charges in ceptacle, commonly termed "mixer," a tank that the metal will be drawn out be- lined with fire brick of sufficient thickness fore it chills; the other is to store a larger to retain the heat of the molten iron, and number of charges in a heated tank,--that of such size and strength as to be capable is to say, in an immense open-hearth fur- of receiving and retaining a large amount pace."

- "say, 100 tons" — of molten iron. This "A few words of history may be of in- reservoir is mounted upon journals, and is terest. Mr Bessemer's early intention was adapted to be tipped so as to receive at one to use blast-furnace metal direct. The ear-endo molten metal from the blast furnaces, lier Bessemer practice, especially that in carried to it in cars, and by being tipped Sweden, was with metal right from the in the other direction, to discharge the same blast furnace. But this practice did not into similar cars, in which it is carried to make headway, except where there was from the converter. The essence of the invention 3 to 5 per cent of manganese in the pig lies in the fact that the tip, is so regulated blown, for reasons just* mentioned; so that by a stop that the reservoir can never be while it soon became standard at Terre- wholly emptied, but a “considerable quannoire and elsewhere in France, as well as tity” of metal always remains,-a dominant in Sweden, and to some extent in Germany, pool, into which successive additions are yet in England it was not only unused, but received. pronounced impracticable so late as Sep- That the invention is one of very considtember, 1874."

erable importance is attested by the fact This difficulty,—and it seems to have been that it was not only put into immediate use 80 serious as to render the direct process in the Edgar Thomson works at Braddock, commercially impracticable, --Jones sought then owned by the plaintiff, but has since to remedy, and did remedy, by creating a been adopted by all the leading steel manucovered reservoir of molten metal between facturers in this country, and by many sim. the blast furnaces and the converters, in ilar works in Europe, where the patent was which should always be maintained a large sold for £10,000. Mr. Carnegie, one of the quantity of metal, happily termed by the witnesses, says of it: “There were both district judge a dominant pool, which advantages and disadvantages [in the direct should be drawn off in small quantities at process used prior to Jones's invention), but a time, and replenished by a like quantity the disadvantages were so great that we of metal from the blast furnaces. In this often debated whether to abandon the proway, while the metals taken from the sev- cess or not. We found it impossible to get eral blast furnaces might differ in their a uniform quality of rails as well as by heat and constituent elements, yet, being' the cupola method.

When we were




[ocr errors]


still anxiously struggling with the problem, | The principal features in this invention and undecided whether to continue or aban- consist in directing the blast to the body don it, Captain Jones told us that or belly of the furnace, as well as to the he believed he had invented a plan which hearth thereof, for the purpose of fusing or would solve the problem. ... We thought smelting the entire mass of ore in the fur. so well of the idea-I was so convinced of nace simultaneously, or nearly so. its reasonableness—that I directed him to The mode hitherto practised in smelting go ahead with his invention.

Cap- furnaces has been to direct blasts into the tain Jones did so, and almost from that day hearth only thereof, thereby requiring sevour troubles ended. He had scored a tre eral hours to smelt or fuse the contents of mendous success; another step forward was a large furnace." The specification is taken in the manufacture of steel, and we somewhat blind, and it is difficult to see are using the invention to-day.

what definite or valuable result is obtained Without this invention I believe that we by the use of several small instead of one should have abandoned the mode of running large furnace, except, perhaps, a quicker direct from the blast furnace. Above all heating and less delay in its practical oper. things, the manufacturer has to regard the ations; but it is sufficient for the purposes uniformity of product, the equality of of this case to say of it that it contains rails; and this uniformity cannot be ob- no suggestion of a mixing of different casts tained without Jones's invention, as far as for the purpose of obtaining a more uni. I know."

form product, and that the invention has It is true that what is termed the direct no relation to a further treatment or reprocess was used in connection with the fining. It does contemplate the use of Bessemer invention in some foreign coun. a reservoir, but there is no suggestion of a tries, notably Sweden and France, with reservation in such reservoir, of a quantity more or less success, due to the peculiar of molten metal. It is not denied that the character of the ores used in those coun. use of a reservoir from which molten metal tries; but such attempts in this country may be drawn long antedated the Jones had proven practically failures, and had patent. But the best that can be said of been abandoned. In regard to this the the Tabberner patent is that, if the reserwitness Kennedy said:

voir had been of sufficient size and properly "The Jones method has made the direct constructed so as to never be completely process, which was attended with great emptied, it might have been adapted to danger and difficulties before the date of carry out the Jones process; but there is his invention, a thoroughly practicable and no evidence that it was ever so constructed, successful one. Instead of it being a ques. or that the production of a uniform diso tion of great doubt whether to run the charge from the reservoir was contemplat. metal direct to the converter or remelt it, ed. That it could not have been intended as it was up to the time of Jones's inven for the purpose of carrying out the Bessetion, no one would now think of building a mer process, or any other process, for the new works containing both furnaces and use of blast-furnace metal in a converter, converters without arranging to mix the is evident from the fact that the patent metal by the Jones method, which not only was nearly simultaneous with the Besse effects an immense saving in the cost of mer patent, of the existence of which the operating the works, but enables a uni- patentee appears to have been entirely ig. formly good product to be made, and also a norant. purer product than can be obtained from

The English patent to Deighton of 1873, cupola metal, which absorbs and is con- for “improvements in the arrangement and taminated by sulphur from the coke which mode of working an apparatus for the man. constitutes the fuel of the cupola."

|ufacture of Bessemer steel," contains the Indeed, the value of the process is not closest approximation to the principle of wholly denied, though much depreciated, by the Jones invention. If this does not anthe defendant, which relies rather upon the ticipate, none does. The primary object of fact that it was well known in the art, and the patent seems to have been to prevent that so far as it is described in the Jones the loss of time while the converters are specification and drawings it was not in being cooled and relined or repaired, and fringed by it.

again* prepared for work, by providing that 1. We now proceed to an examination of the converting vessel shall be so arranged the question of anticipation, in support of that it can be readily detached from its acwhich a number of English patents are tuating mechanism and lifted bodily out of produced, which will be briefly considered: its bearings by a suitable crane or other First, the British patent to Tabberner of lifting mechanism, and a spare converter 1856, the object of which was, as stated by substituted in its place. the patentee in his specification, “to dis. There is, however, a further provision in pense with the necessity of employing onc the patent, as follows: or more large furnaces, and to use in lieu “Instead of manufacturing Bessemer iron thereof several small furnaces, the com- or steel from pig iron, which has been melt. bined capacities whereof are equal to that ed in cupolas, my invention also consists in of one or more large furnaces, and to cause taking the molten metal directly from the these small furnaces to discharge their con- blast furnace to the converter, in which case tents at short intervals of time into one I prefer to arrange the Bessemer plant in a large reservoir, from which the molten line at a right angle to a row of two or metal may be drawn for casting from. ... more blast furnaces, and place a vessel to


receive the molten metal tapped from two sence of a cover is conclusive that it is not or more blast furnaces to get a better aver- 80 used. age of metal which will be more suitable It is insisted, however, that defendants for makirig Bessemer steel or metal of uni- have demonstrated, by practical experi. form quality, the vessel or receiver being mentation with a plant constructed accordplaced on a weighing machine so that any ing to the specification of the Deighton patrequired weight may be drawn or tapped ent, that the results are practically the from it and charged into the converter." same as those obtained by the Jones pro

The specifications provide for manufac- cess. This plant, however, was constructed turing Bessemer steel directly from the after suit brought, long after the Deighton smelting furnace by employing gates or patent had been allowed to expire, and with channels for molten metal from each fur: no opportunity afforded the plaintiffs to in. nace, leading to a reservoir, which is placed spect the plant or witness its operation. low enough to give fall for the molten met. The tank was fitted with a cover, and a con. al to flow from the blast furnace to this stant pool of molten metal retained in it; reservoir, which forms a receptacle for mix. but this was not the Deighton process, but ing the molten metal from two or more of the Jones process adapted to the Deighton the smelting furnaces. From the reservoir device. Were this evidence admissible at the mixed molten metal is tapped, and flows all, we are satisfied that it is met by the down the swivel trough into the convert. fact that if the Deighton patent had been er. By placing the reservoir on a weighing adaptable to the Jones process, it is scarcely machine, it can be readily ascertained when possible* that its merits should have failed the exact quantity required has been tapped to seize upon the attention of manufacturfrom it into the converter. The sixth


who would have brought the patent in. claim of the patent is for “the system or to general use, instead of allowing it to mode of arranging and working Bessemer lapse for the nonpayment of a comparative converters with a receiver or receptacle for ly small fee. As something in the nature mixing the molten metal from two or more of the Jones process was needed to enable smelting furnaces to get a more uniform steel to be manufactured directly from the quality of metal, substantially as hereinbe- product of blast furnaces, the utility of the fore described and illustrated by the draw. Deighton patent for that purpose would at ings.”

once have been recognized and its success While Deighton seems to have conceived assured. But evidently that patent was the idea that uniformity of product was not the final step in the accomplishment of necessary to the successful use of the direct the mixing process. It contributed noth. process, and might be attained by mixing ing to the art of manufacturing steel, and, the discharge from several blast furnaces although issued in 1873, was allowed to in an open reservoir, standing* between the lapse in 1876, after an apparently unprofit furnaces and the converter, the dominant able existence for three years, by reason of idea of the Jones invention, that a constant the nonpayment of the stamp duty, neces. quantity of molten iron should always be sary to keep it alive. It is sufficient to kept in such reservoir to serve as a basis say of it that it fails to disclose, fully and for such mixture and an equalizer of the precisely, the essential features of the prodifferent discharges, does not seem to have cess covered by the Jones patent. Walker, occurred to him. As the discharge pipe Patents, $ 54; Seymour v. Osborne, 11 was located at the bottom of the reservoir, Wall. 5 lv, 555, 20 L. ed. 33, 42; Illinois C. R. it was certainly possible to empty it entire. Co. v. T'urrill, 94 U. 8. 704, 24 L. ed. 241. ly, and the testimony in the case indicates Although Deighton was an employee of that this was the natural method of opera- the Moss Bay Company of Workington, tion. If this were so, then the reservoir England, if any attempt were made by this accomplished nothing beyond the mixing of company to make use of his process, it evi. each batch of metal introduced into it from dently amounted to nothing, since one of the different blast furnaces. There is no- the writers, Snelus, contributing to the where in the specification a suggestion of Journal of the Iron and Steel Institute, supplying to and withdrawing from the 1876, says: “One great drawback to the reservoir small amounts at a time, a con- direct casting process was that you could stant quantity of metal being retained in not always get your metal at the exact the reservoir for the purpose of equalizing time you wanted it. He believed that it the different products of the blast furnaces. would be found that the great advantage While the Deighton reservoir, if a cover the Bessemer works in America had was the had been added to it, might perhaps have intermediate receiving ladle, which was debeen utilized for that purpose, there is no signed by Mr. Holley, and which was uni. evidence that such use ever occurred to the versally used there, although it was never inventor. Indeed, the absence of a cover to used in England. The Moss Bay Company the reservoir is evidence, even to a nonex- | attempted to modify the thing some time pert, that it was not contemplated that a ago, and put up a heating furnace; but permanent quantity of molten iron should that, to his mind, was a step in the wrong be retained in it, since a radiation of heat direction. Anyhow, the thing had failed, would thereby be produced and the con- and no one in England, so far as he knew, tents skulled or crusted over with a layer was using any intermediate receiver be of refuse iron or slag. The testimony is tween the blast furnace and the convertclear that the Jones process cannot be car. I ers." ried on in an open reservoir, and the ab- This defense presents the common in.


22 S. C.-45.


stance of a patent which attracted no at. | duct of the blast furnace. This metal is tention, and was commercially a failure, usually cast in the form of pigs, then rebeing set up as an anticipation of a subse melted in the cupola as needed, before bequent patent which has proved a success, ing charged into the converter. because there appears to be in the mechan. It is very desirable to take advantage of ism* described a possibility of its having the molten condition of the metal as it been, with some alterations, adaptable to comes from the blast furnace for its use in the process thereafter discovered. As here the converter, because thereby the remeltinafter observed, a process patent can only ing of the metal and the expense of the conbe anticipated by a similar process. It is struction of a cupola may be avoided. The not sufficient to show a piece of mechanism charge of the converter is from one to five by which the process might have been per- tons, and the casting of a blast furnace formed.

runs usually from ten to fifty tons. The In the American patents to Durfee, Nos. difficulty of using the molten metal from 118,597 and 122,312, both of 1871, the de. the furnace to the converter consists in sirableness of manufacturing steel directly keeping the large quantity of metal from from the blast furnace is recognized, and the latter in a proper molten condition for in his second patent he says:

"That in the use in the former. He proposed to remmanufacture of steel by the pneumatic or edy this by a reservoir provided with a Bessemer process a great saving of fuel and suitable cover and with tuyeres "which blow iron, of wear and tear of furnaces, and of down upon the surface of the metal for the labor, would be effected were it possible to purpose of maintaining its heat and fluidi. make uniformly good products of the desired ty." As this reservoir was apparently temper by converting the crude iron imme- adapted to hold a single cast, and therefore diately it is tapped from the blast furnace must be emptied before another cast was in which it is made. This plan has been received into it, it was impossible that and may still be practised to a considera. Witherow intended by its use to practise ble extent, but it has been found that, by the Jones process. There is no suggestion reason of the irregular working of blast anywhere in the patent of a desire to retain furnaces and the consequent varying char- a quantity of metal in the reservoir to serve acter and quality of the crude iron pro- as a basis for mixing the various products duced, it was always very difficult and in of the blast furnace, which was the domi. most cases impossible to secure such uni-nant idea of the Jones patent. To antici. formity in the converted metal as was es. pate a process patent, it is necessary not sential to success in the business. Hence. only to show that the prior patent might at several establishments where the plan of have been used to carry out the process, taking the fluid iron as it was tapped from but that such use was contemplated, or that the blast furnace, and pouring it at once the leading idea of the Jones patent of into the converter, had been practised, it maintaining a dominant pool in the reser. has been abandoned, the proprietors prefer: voir was such a use of the Witherow patring to incur the expense of handling and ents as would have occurred to an ordinary remelting the crude iron after it had been mechanic in operating his device. Wheth. cast into pigs, in order thus to secure the er the reservoir in the Witherow patent advantage of carefully selecting and mixing was partly or fully emptied seems to have the materials for each charge to be convert- been a matter of complete indifference to ed."

the inventor, and the idea of maintaining: He proposed to accomplish this by using a constant quantity therein seems to have a reverbatory gas furnace, into which the f*never been conceived by him. His design crude iron from the blast furnace is poured, seems to have been merely to provide a resand in which it may be mixed with other ervoir for the storage of the large quantity irons, and so treated as to insure uniformi. of metal from the blast furnaces, and to ty. Pig iron of different qualities, or any maintain its heat until the comparatively metals or metalloids or fluxes, can be add- small quantities required in the converters ed and mixed with the metal as may be had been drawn off for use. As he states necessary to bring it to the required char- in his specification: "The metal is usual. acter. The process is so manifestly differ- ly tapped from a blast furnace once in every ent from that described by Jones that it six hours, and the quantity thus cast is demands no further attention. If it were many times in excess of the charge of a put in practice at all, it seems to have converter,” which is from one to five tons," proved à failure, as, although an English while “the cast of a blast furnace runs usupatent was taken out by Durfee, it was al. ally from ten to fifty tons." While the lowed to lapse by reason of the nonpayment metal is tapped from the blast furnace once of the stamp duty.

in every six hours, "the time between * Two American patents to James P. With charges in the converter is usually twenty erow, No. 315,587 and No. 327,425, both is. ininutes and upwards, and the metal in the sued in 1885, are pressed upon our atten- furnace must be kept in condition to be tion. In the second patent, the only one tapped from time to time into the converter necessary to notice, he restates the advan- as needed." This appears to have been the tages of the direct process and the difficul. whole object of the invention. ties theretofore encountered in its practi. The same remark may be made of all cal operation. “In the manufacture of these prior devices. While all contemplate steel by the pneumatic process, the convert the reservoir between the blast furnaces and ers are charged with molten metal, the pro. 'the converters, such reservoir is used for


« AnteriorContinuar »