Page:EB1922 - Volume 31.djvu/628

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
590
IRIGOYEN—IRON AND STEEL

addressed in that language. It was observed that many of these people came to a violent end, and the wearing of this ring was con- sequently to some extent discontinued. Finally it may be said that whilst the reading, writing and speaking of the Irish language have increased very much amongst the cultured classes in the towns, the language, where it is still naturally spoken in the north-west, west and north, has not fared equally well, and it is in many of these places barely holding its own against English. (D. HY.)

IRIGOYEN, HIPÓLITO (1853- ), President of Argentina, was born in Buenos Aires in 1853. He attended private schools, the Colegio Nacional, and for three years the Facultad de Derecho, in Buenos Aires. He early became identified with the activities of the Union Civica (see 2.472), of which his uncle, Leandro N. Alem, was a founder, and in 1890 he was in charge of a revolutionary force attacking Buenos Aires. From 1891 to 1909 he was professor of civic instruction in the Universidad de Buenos Aires, and for many years held at the same time a similar chair in the Escuela Normal de Mujeres. On the death of Alem he succeeded him as head of the Radical party, which nominated him president in 1916. On March 1 2 he was elected president, re- ceiving 152 out of the 298 votes of the Electoral College, and on Oct. 12 was inaugurated as the successor of Dr. Saenz Pena (see ARGENTINA). He was the first Radical to hold this office. He possessed considerable wealth and neither as teacher nor president did he accept his salary, but turned it over regularly to the Sociedad de Beneficencia for use in charities.

IRON AND STEEL (see 14.801*). Developments in the second decade of the 2oth century in iron and steel were improvements in processes and equipment rather than new methods. An increase in the per capita consumption, far greater than the remarkable increase of the preceding decade, forced attention to means of securing maximum outputs as well as to the ever- present effort to secure economies. Larger units of manufacture were generally favoured and so-called " duplexing " and " tri- plexing " were outstanding features in steel-making. The latter part of the decade was marked also by a marvellous growth in popularity of the electric furnace, until at the end of 1920 there were 960 such furnaces in the world for steel-making alone, against 114 in 1910. The World War gave an artificial stimulus in general to plant expansion to meet the demands for ships and shells and resulted in a realignment of national capacity. In the main the following analysis is devoted to the economic side of the evolution of the decade.

Iron Blast-Furnace Construction. Design was influenced by local experience of experts in the different iron-producing dis- tricts. Profiles depend on raw materials quality of coke, nature and concentration of ores. Generally speaking, tendency toward greater bosh and shaft angles continued (bosh angle 75 to 80; shaft angle 84 to 86). The size of stack increased only in the districts treating low-grade ore, while with high-grade ore (50% to 62% iron) the 500- to 6oo-ton-per-day size became the standard and many old furnaces were enlarged. In the Minette district of Europe, where the ore charged contained between 30% and 35% iron, the 200- to 2$o-ton unit became popular in all new construction. The cubical capacity of a blast furnace range between 40 and 100 cub. ft. per ton of pig-iron blown in 24 hours. Individual parts of blast furnaces received particular attention. The hearth construction became reenforced and often cooled to avoid breakouts of the molten metal, and greater attention was given to brickwork to limit the downward destructive action of the metal. Emergency tuyeres at mid-height of the bosh standard in the Minette district lost their popularity and dis- appeared in nearly all new furnaces. For the handling of the material ore, limestone and coke mechanical devices won increased favour owing to the enormous masses involved and to the growing scarcity of labour. In America the simple skip hoist was almost universally adopted in new plants, while in Europe the drop-bottom-bucket hoist became popular and its design was ingeniously varied. It is noteworthy that the drop- bottom bucket, which was originated in America (Duquesne works) and was perfected in Germany during the years 1905-10, was little used in the United States 10 years later. It had been supplanted by the cup-and-cone top with a rotary dis-

tributor (McKee), while in Europe the double cup-and-cone construction, giving low drop height and assuring less breakage of the softer coke, was preferred. These two solutions were more or less linked to the hoist system adopted. The furnace interiors were bricked up in America of standard-shaped refractories giving a multitude of joints, while it was customary all over Europe to use special large-volume brick, shaped to reduce the joints. Both systems seemed to give satisfaction to the opera- tors, and comparisons were not possible owing to the difference in the operating conditions. Speaking generally, the American design with a plate lining involved less steel for construction, while the Luxemburg-Lorraine type of blast furnace was con- servative and substantial.

Blast-Furnace Operation. General progress was marked; greater familiarity with the chemical problems and increased mechanical equipment made operation more easily controllable, results more positive and disturbances less frequent. The use of excessively fine ore was accompanied by a high-solution loss of coke, and agglomerating of ore was recognized as desirable. This led to increasing attention to sintering fine ore mixed with flue-dust, and recharging of dust without treatment seemed likely to die out. Higher temperature of the air blast was a noteworthy development, as each increase of 200 F. has been reflected by 4% to 5% reduction in coke consumption. In the Minette district 850 to 900 F. blast temperatures were quite common. The blast pressure, which remained without much change, varied according to districts and the forcing of the operation, from 4 to 15 Ib. per square inch. In case of a rela- tively cold spell within the furnace due to overfluxing, bad coke or dropping of a hanging, the introduction of kerosene (paraffin) through the tuyeres proved a quick remedy, although it neces- sarily required care and progressive application to avoid accidents. The use of this cure rendered superfluous the auxiliary tuyeres at mid-height of bosh. The use of the oxygen torch to burn out the iron notch in case of metallic incrustations extremely difficult to remove proved a great help to the working crews. Mechanical appliances in cast-houses were installed in increasing numbers to supplant hand work, especially in sand casting floors. Cranes equipped with lif ting magnets and pneumatic hammers elastically suspended proved a step toward the best method of moulding, breaking and handling of sand-cast pig-iron. For all qualities of pig-iron the continuous casting machines continued to be the accepted standard. In plants adjoining steel-works transport ladles of larger size (30 to 50 tons) and designs assuring better insulation and easier skimming of slag were evolved.

Blast-Furnace Gas. Continuously increasing price of coal and coke affected the economics of the blast-furnace gas and made it a by-product of great importance. The fuel value of this original waste became more and more recognized in America. The first effort, to avoid all gas losses so far as possible, led to the installation of double furnace tops, which became universal. Next gas-cleaning processes were developed to remove dust impurities from the by-product fuel, thus increasing its adaptability to combustion and securing greater efficiencies in its utilization. To facilitate operation and render supervision automatic, pressure-regulating devices were evolved and accumulators were installed to equalize supply and provide steady outflow. Gas-cleaning attracted the attention of operators in European countries greatly in need of fuel, because the calorific value of the gas counterbalanced the cost of purification. In America the coal shortage, due to inordinate demand and dislocation of railway service, produced the same result. The first step in gas-cleaning was the installation of a dust collector close to the offtakes and the downcomers of each blast furnace. In it the coarse dust was deposited by a slowing-down of the gas flow and a sudden change in its direction. This apparatus was independent of all further cleaning methods.

To separate the fine dust particles two different processes were applied: (1) wet method; (2) dry filtration.

(1) By the wet method the gases were cooled by injection of water, and the dust particles, passing through the fog artificially produced, were arrested by scrubbers. Experience led to a subdivi-

  • These figures indicate the volume and page number of the previous article.