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A new type of electric furnace
CURRENT ToPics.
639
A N e w T y p e of Electric F u r n a e e . - - A b s t r a c t . At the recent meeting of the American Electrochemical Society in New York, Mr. Carl Hering described a new electromagnetic phenomenon which he has named the " squirt phenomenon " and which he is using as the basis of a new type of electric furnace, for which he claims it is particularly well adapted. This new phenomenon is as follows: If an electric current is passed lengthwise through a liquid conductor, like a molten metal which is confined in a tube or hole closed at the bottom by the electrode, and opening at the top into a bath of the molten material-then the liquid in the hole will be squirted out axially quite forcibly through the contral part of the open end, and other liquid will be forcibly sucked down into the hole around its periphery, provided the relation of the current to the cross section of the liquid conductor is sufficiently great. It may be said to be a valveless pump clrculating the liquid rapidly throughout the hole. If this hole is located in the bottom of a crucible or hearth and is so proportioned that the current will produce the necessary heat itr the material in it, by virtue of its electrical resistance, the device will constitute a new kind of furnace, in which the liquid in the hole constitutes the resistor; it may be said to be a furnace with a " flowing resistor." The cooler liquid material flows down into this hole near the circumference, becomes heated by the current and is then at once expelled with considerable force to the top of the bath, where, in the case of the refining of steel, it comes into direct and intimate contact with the blanket of slag which takes up the impurities mechanically and chemically. In the furnace there are, of course, two such flowing resistors, one for each electrode. The chief claims made for furnaces based on this principle are: greater heat economy, as the heat is all generated directly where it is wanted, without waste ; much greater rapidity of refining, when the furnace is intended for steel refining, on account of the enormous and continually changing s~rface exposed to slag action; hence greater fm:nace capacity per day and greater heat economy, due to the shorter time of treatment; great homogeneity of the product due to the very rapid circulation; cheapness of construction, as the furnace consists merely of two holes in the bottom of a hearth, plugged with the two electrodes; no unnecessarily high temperatures with their attending heat losses; no consumption of electrodes with its attending costs ; ease and nicety of regulation ; no machinery for regulating an arc; applicability also to zinc and arsenic ores, glass, etc. ; adaptability to being added to existing open-hearth furnaces or pots; possibility of adding fuel heat at the top of the lower temperatures; an arc may be added if desired; etc. The force wtg~_h produces this squirting action is caused by the so-called " pinch effect," described by the author some years ago. which is a radial force tending to contract the cross section of a conductor as though it were being pinched or squeezed; in the squirting phenomenon this radial force is made use of to produce VOL. CLXXI, No. Io26--47
640
CURRENT TOPICS.
a pressure at the centre and a suction at the circumference, which in turn produce the upward and downward flows of the liquid. The forces were found to be surprisingly great, hence the heating m a y be made to be very rapid, as the heated liquids are expelled very quickly, the particles of the material being in the hole only a moment, probably not more than a second or two. Trial furnaces have operated very successfulIy. P r e s e r v i n g T i m b e r . ANON. (Eng. Record, lxiii, 3 I O . ) - - T h e penetration of timber preservatives to be expected from the amounts of preservative usually specified are given by Mr. R. L. Allardyee, superintendent of the International Creosoting and Construction Co., of Texarkana, Tex., as the results of his experience. The figures refer to Southern pines treated by the full. cell method. Bearing in mind the many variations in conditions, a fair average, based on numerous borings is given as 3~ to i ~ inches, in soft or sap wood for a Io to 12 pound treatment on piling, using dead oil of coal tar; I ~ to 2 ~ or 3 inches for a 14 to 16 pound treatment ; 3 ~ to 4 inches for a 20 pound treatment and 4 ~ inches to complete penetration for 22 to 24 pounds. In heart wood the penetration is less. I n a straight zinc or Bnrnettized treatment of loblolly ties, a 20 pound treatment of a light solution is given for complete penetration, or up to the last ~ or I ~ inches from the centre. F o r short leaf or long leaf pine ties a stronger solution is recommended and never less than ioo pounds per square inch pressure during treatment. P r o t e c t i o n of Tools f r o m Corrosion. ANON. (Amer. Mac&, xxxiv, I 9 3 . ) - - T o o l s can be kept clean and bright by coating then with mercurial ointment, known as " b l u e butter," which resists moisture. It should be handled carefully as it is somewhat poisonous. Another good resistent is made by heating 6 parts of lard with i part of rosin till the rosin is melted. Remove mixture from the fire to a safe place and add about I pint of benzine to each hail-pound of the lard-rosln mixture. W h e n cool, rub the mixture over bright steel articles. Tools treated in this way will resist the corrosion of even salt water. Nitrification b y the Ultra-violet Rays. D. BERTHELOT AND H. GAImEC~ION. (Rev. Scient., xlix, 3 1 4 . ) - - T h e nitrification of aqueous solutions of ammonia, or of ammoniacal salts, or of nitrogenous organic bodies, can be caused by the ultra-violet rays in the presence of oxygen gas. The oxidation ceases at the nitrous stage, and inversely nitrates are reduced to nitrites. In concentrated solutions the reduction is carried still further, and as a 0ar-ticulav case, ammonium nitrate disengages pure nitrogen gas. ~l'he ultra-vlolet rays act as ferments; and according" to circumstances, cause a gain or loss of combined nitrogen.
639
A N e w T y p e of Electric F u r n a e e . - - A b s t r a c t . At the recent meeting of the American Electrochemical Society in New York, Mr. Carl Hering described a new electromagnetic phenomenon which he has named the " squirt phenomenon " and which he is using as the basis of a new type of electric furnace, for which he claims it is particularly well adapted. This new phenomenon is as follows: If an electric current is passed lengthwise through a liquid conductor, like a molten metal which is confined in a tube or hole closed at the bottom by the electrode, and opening at the top into a bath of the molten material-then the liquid in the hole will be squirted out axially quite forcibly through the contral part of the open end, and other liquid will be forcibly sucked down into the hole around its periphery, provided the relation of the current to the cross section of the liquid conductor is sufficiently great. It may be said to be a valveless pump clrculating the liquid rapidly throughout the hole. If this hole is located in the bottom of a crucible or hearth and is so proportioned that the current will produce the necessary heat itr the material in it, by virtue of its electrical resistance, the device will constitute a new kind of furnace, in which the liquid in the hole constitutes the resistor; it may be said to be a furnace with a " flowing resistor." The cooler liquid material flows down into this hole near the circumference, becomes heated by the current and is then at once expelled with considerable force to the top of the bath, where, in the case of the refining of steel, it comes into direct and intimate contact with the blanket of slag which takes up the impurities mechanically and chemically. In the furnace there are, of course, two such flowing resistors, one for each electrode. The chief claims made for furnaces based on this principle are: greater heat economy, as the heat is all generated directly where it is wanted, without waste ; much greater rapidity of refining, when the furnace is intended for steel refining, on account of the enormous and continually changing s~rface exposed to slag action; hence greater fm:nace capacity per day and greater heat economy, due to the shorter time of treatment; great homogeneity of the product due to the very rapid circulation; cheapness of construction, as the furnace consists merely of two holes in the bottom of a hearth, plugged with the two electrodes; no unnecessarily high temperatures with their attending heat losses; no consumption of electrodes with its attending costs ; ease and nicety of regulation ; no machinery for regulating an arc; applicability also to zinc and arsenic ores, glass, etc. ; adaptability to being added to existing open-hearth furnaces or pots; possibility of adding fuel heat at the top of the lower temperatures; an arc may be added if desired; etc. The force wtg~_h produces this squirting action is caused by the so-called " pinch effect," described by the author some years ago. which is a radial force tending to contract the cross section of a conductor as though it were being pinched or squeezed; in the squirting phenomenon this radial force is made use of to produce VOL. CLXXI, No. Io26--47
640
CURRENT TOPICS.
a pressure at the centre and a suction at the circumference, which in turn produce the upward and downward flows of the liquid. The forces were found to be surprisingly great, hence the heating m a y be made to be very rapid, as the heated liquids are expelled very quickly, the particles of the material being in the hole only a moment, probably not more than a second or two. Trial furnaces have operated very successfulIy. P r e s e r v i n g T i m b e r . ANON. (Eng. Record, lxiii, 3 I O . ) - - T h e penetration of timber preservatives to be expected from the amounts of preservative usually specified are given by Mr. R. L. Allardyee, superintendent of the International Creosoting and Construction Co., of Texarkana, Tex., as the results of his experience. The figures refer to Southern pines treated by the full. cell method. Bearing in mind the many variations in conditions, a fair average, based on numerous borings is given as 3~ to i ~ inches, in soft or sap wood for a Io to 12 pound treatment on piling, using dead oil of coal tar; I ~ to 2 ~ or 3 inches for a 14 to 16 pound treatment ; 3 ~ to 4 inches for a 20 pound treatment and 4 ~ inches to complete penetration for 22 to 24 pounds. In heart wood the penetration is less. I n a straight zinc or Bnrnettized treatment of loblolly ties, a 20 pound treatment of a light solution is given for complete penetration, or up to the last ~ or I ~ inches from the centre. F o r short leaf or long leaf pine ties a stronger solution is recommended and never less than ioo pounds per square inch pressure during treatment. P r o t e c t i o n of Tools f r o m Corrosion. ANON. (Amer. Mac&, xxxiv, I 9 3 . ) - - T o o l s can be kept clean and bright by coating then with mercurial ointment, known as " b l u e butter," which resists moisture. It should be handled carefully as it is somewhat poisonous. Another good resistent is made by heating 6 parts of lard with i part of rosin till the rosin is melted. Remove mixture from the fire to a safe place and add about I pint of benzine to each hail-pound of the lard-rosln mixture. W h e n cool, rub the mixture over bright steel articles. Tools treated in this way will resist the corrosion of even salt water. Nitrification b y the Ultra-violet Rays. D. BERTHELOT AND H. GAImEC~ION. (Rev. Scient., xlix, 3 1 4 . ) - - T h e nitrification of aqueous solutions of ammonia, or of ammoniacal salts, or of nitrogenous organic bodies, can be caused by the ultra-violet rays in the presence of oxygen gas. The oxidation ceases at the nitrous stage, and inversely nitrates are reduced to nitrites. In concentrated solutions the reduction is carried still further, and as a 0ar-ticulav case, ammonium nitrate disengages pure nitrogen gas. ~l'he ultra-vlolet rays act as ferments; and according" to circumstances, cause a gain or loss of combined nitrogen.