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Washing oils for the removal of naphthalene from coal gas
29o
CURRENT TOPICS.
strength of the cast iron to which it is added from IO to 25 per cent., depending on the initial strength of the iron. It causes a more even distribution of the graphite, with consequent greater freedom from both hard and porous spots, thus giving a finer and more uniform grain. In chilled iron vanadi'um produces a deeper, stronger and tougher chill, which is less liable to spall or flake. This chill is not so hard as the more brittle ordinary chill, and can be filed and machined more readily. Vanadium also toughens the iron and makes a superior cast iron. The usual amount of vanadium added to cast iron is I / I O of I per cent. for cupola melted iron, or about 5 oz. of ferro-vanadium for each Ioo lbs. Some foundries advocate a higher percentage, up to 15 per cent. F o r higher grade air furnace iron the addition of o.18 to o.2o per cent. of vanadium is recommended.
Washing Oils for the Removal of Naphthalene from Coal Gas.
A. BAYER. (J. Gcabeleucht, liv, 4 9 6 . ) - - F o r the removal of naphthalene from coal gas the author uses a light oil of the following composition: Benzene 0.4. light oil ( i o o ° - i 8 o ° C . ) 67.6, middle oil (I8O°-23o°C.) 25.o, naphthalene 3.9, and heavy oil 3.1 per cent. This thoroughly removes the naphthalene and imparts light and middle oil to the gas, which seem to assist in the removal of naphthalene, which may have got into the mains. The naphthalene is found dissolved in the condensed hydrocarbons at various points in the system. Light oil gives much better results than heavy oil or than a mixture of heavy and middle oil. T i t a n i u m in Iron and Steel. CHAS. V. SLOCUM. (,4mer. Mech., xxxiv, i I 6 5 . ) - - T h i s interesting paper is worth perusal and may be summarized as follows: Small percentages of titanium will successfully produce many of the benefits of a large quantity. For instance, the use of two-tenths of I per cent. of alloy, containing IO per cent. of t i t a n i u m , that is, the use of 0.02 per cent. of metallic titanium, is frequently sufficient to clean the iron of the impurities remaining in the metal after the ordinary fluxes have accomplished all they can. Titanium removes the oxides and nitrides from molten iron, increases the fluidity, and makes the metal m o r e homogeneous, so that. the castings are closer grained, free from pin-holes and gas bubbles, and the iron has a denser structure and is easily machined, o.I to 0.2 per cent. of the alloy is sufficient to make viscous high-chilling mixtures come from the cupola close-grained and pour freely. The cost of the titanium is compensated by the use of less manganese and a trifle less silicon. The expense runs from 25c. per ton of castings up to say $3 as a maximum, which is often repaid in the reduction of bad work and in the improvement of poor irons. The same holds good for steel castings. One great advantage of the regular use of the titanium
CURRENT TOPICS.
strength of the cast iron to which it is added from IO to 25 per cent., depending on the initial strength of the iron. It causes a more even distribution of the graphite, with consequent greater freedom from both hard and porous spots, thus giving a finer and more uniform grain. In chilled iron vanadi'um produces a deeper, stronger and tougher chill, which is less liable to spall or flake. This chill is not so hard as the more brittle ordinary chill, and can be filed and machined more readily. Vanadium also toughens the iron and makes a superior cast iron. The usual amount of vanadium added to cast iron is I / I O of I per cent. for cupola melted iron, or about 5 oz. of ferro-vanadium for each Ioo lbs. Some foundries advocate a higher percentage, up to 15 per cent. F o r higher grade air furnace iron the addition of o.18 to o.2o per cent. of vanadium is recommended.
Washing Oils for the Removal of Naphthalene from Coal Gas.
A. BAYER. (J. Gcabeleucht, liv, 4 9 6 . ) - - F o r the removal of naphthalene from coal gas the author uses a light oil of the following composition: Benzene 0.4. light oil ( i o o ° - i 8 o ° C . ) 67.6, middle oil (I8O°-23o°C.) 25.o, naphthalene 3.9, and heavy oil 3.1 per cent. This thoroughly removes the naphthalene and imparts light and middle oil to the gas, which seem to assist in the removal of naphthalene, which may have got into the mains. The naphthalene is found dissolved in the condensed hydrocarbons at various points in the system. Light oil gives much better results than heavy oil or than a mixture of heavy and middle oil. T i t a n i u m in Iron and Steel. CHAS. V. SLOCUM. (,4mer. Mech., xxxiv, i I 6 5 . ) - - T h i s interesting paper is worth perusal and may be summarized as follows: Small percentages of titanium will successfully produce many of the benefits of a large quantity. For instance, the use of two-tenths of I per cent. of alloy, containing IO per cent. of t i t a n i u m , that is, the use of 0.02 per cent. of metallic titanium, is frequently sufficient to clean the iron of the impurities remaining in the metal after the ordinary fluxes have accomplished all they can. Titanium removes the oxides and nitrides from molten iron, increases the fluidity, and makes the metal m o r e homogeneous, so that. the castings are closer grained, free from pin-holes and gas bubbles, and the iron has a denser structure and is easily machined, o.I to 0.2 per cent. of the alloy is sufficient to make viscous high-chilling mixtures come from the cupola close-grained and pour freely. The cost of the titanium is compensated by the use of less manganese and a trifle less silicon. The expense runs from 25c. per ton of castings up to say $3 as a maximum, which is often repaid in the reduction of bad work and in the improvement of poor irons. The same holds good for steel castings. One great advantage of the regular use of the titanium