- Email: [email protected]
Corrosion of boiler-tube due to carbonic acid
1 16
CURRENT TOPICS.
[J. F. I.
Grindstones and P u l p s t o n e s . - - A c c o r d i n g to reports submitted to the United States Geological Survey, 44,832 tons of grindstones, valued at $I,239,99o, were sold in I92O. T h e sales in I9I 9 a m o u n t e d to 4o,755 tons, valued at $993,959. This material was p r o d u c e d from sandstone quarries in Michigan, Ohio, and W e s t Virginia. T h e sizes of the grindstones v a r y greatly and are reported as square grindstones, from ~ inch to 8 inches in diameter, :and as lathe stones, from 6 to I2 inches in diameter, and as grind:stones, from less than a foot in diameter and less than a pound in w e i g h t to large stones 6 to 7 feet in diameter, 8 inches to a foot ,or more in thickness, and from I to 2 tons in weight. T h e prices of the stones differ according to the size and quality of the stone. T h e smaller sized stones, which are sold b y the piece, show a much higher average value per ton than the large stones. The ordinary sizes were reported to range from $23 to $4o per ton f.o.b. (unm o u n t e d ) at the quarry. T h e average value per short ton, of all t h e g r i n d s t o n e material sold in I92O was $27.66; the average in I9I 9 was $24.39. P u l p s t o n e s are h e a v y stones used for g r i n d i n g ycood into fine fibre for m a k i n g pulp and paper. T h e s e stones are generally 54 inches in diameter and 27 inches thick and weigh a b o u t 2 tons, b u t s o m e machines require stones 62 inches in diameter, 54 inches thick, and that weigh a b o u t 4 tons. T h e p r o d u c t i o n in I92o was 8652 tons, valued at $467,oi4, and in IgI 9 it was 6I IO tons, valued a t $342,o56. T h e average value per ton was $54 in I92o and $56 in I9I 9. P u l p s t o n e s were obtained from quarries in Ohio and W e s t Virginia. Business conditions in this i n d u s t r y were unsettled t h r o u g h out the year, and t h o u g h the d e m a n d was good the sales were lessened by difficulties with t r a n s p o r t a t i o n and with labor. Corrosion of Boiler-tube Due to Carbonic A c i d . - - B . G. W o r t h presented to the 39th general meeting of the American ElectroChemical Society a paper describing an unusual corrosion of a steam boiler. All attempts to control the action by electrolytic means failed. The chemist at the plant found that a notable quantity of ferrous carbonate was held in solution by excess of carbonic acid, which is a notinfrequent condition in ground waters. It is rather remarkable that the.water-softening plant was not originally adapted to deal with this condition, as it is generally evident by the change of the water from clear to a reddish turbidity on standing a short time exposed to the air, and still more quickly if aerated. Corrosion of metals by natural waters has been a subject of extensive study, and among other conditions a water containing much dissolved air, with very little scaleforming material will often produce notable corrosion, especially if the feed water is introduced by a tube terminating at the boiler wall. The corrosion is generally less if the tube is prolonged to, or near, the centre of the water-mass. H.L.
CURRENT TOPICS.
[J. F. I.
Grindstones and P u l p s t o n e s . - - A c c o r d i n g to reports submitted to the United States Geological Survey, 44,832 tons of grindstones, valued at $I,239,99o, were sold in I92O. T h e sales in I9I 9 a m o u n t e d to 4o,755 tons, valued at $993,959. This material was p r o d u c e d from sandstone quarries in Michigan, Ohio, and W e s t Virginia. T h e sizes of the grindstones v a r y greatly and are reported as square grindstones, from ~ inch to 8 inches in diameter, :and as lathe stones, from 6 to I2 inches in diameter, and as grind:stones, from less than a foot in diameter and less than a pound in w e i g h t to large stones 6 to 7 feet in diameter, 8 inches to a foot ,or more in thickness, and from I to 2 tons in weight. T h e prices of the stones differ according to the size and quality of the stone. T h e smaller sized stones, which are sold b y the piece, show a much higher average value per ton than the large stones. The ordinary sizes were reported to range from $23 to $4o per ton f.o.b. (unm o u n t e d ) at the quarry. T h e average value per short ton, of all t h e g r i n d s t o n e material sold in I92O was $27.66; the average in I9I 9 was $24.39. P u l p s t o n e s are h e a v y stones used for g r i n d i n g ycood into fine fibre for m a k i n g pulp and paper. T h e s e stones are generally 54 inches in diameter and 27 inches thick and weigh a b o u t 2 tons, b u t s o m e machines require stones 62 inches in diameter, 54 inches thick, and that weigh a b o u t 4 tons. T h e p r o d u c t i o n in I92o was 8652 tons, valued at $467,oi4, and in IgI 9 it was 6I IO tons, valued a t $342,o56. T h e average value per ton was $54 in I92o and $56 in I9I 9. P u l p s t o n e s were obtained from quarries in Ohio and W e s t Virginia. Business conditions in this i n d u s t r y were unsettled t h r o u g h out the year, and t h o u g h the d e m a n d was good the sales were lessened by difficulties with t r a n s p o r t a t i o n and with labor. Corrosion of Boiler-tube Due to Carbonic A c i d . - - B . G. W o r t h presented to the 39th general meeting of the American ElectroChemical Society a paper describing an unusual corrosion of a steam boiler. All attempts to control the action by electrolytic means failed. The chemist at the plant found that a notable quantity of ferrous carbonate was held in solution by excess of carbonic acid, which is a notinfrequent condition in ground waters. It is rather remarkable that the.water-softening plant was not originally adapted to deal with this condition, as it is generally evident by the change of the water from clear to a reddish turbidity on standing a short time exposed to the air, and still more quickly if aerated. Corrosion of metals by natural waters has been a subject of extensive study, and among other conditions a water containing much dissolved air, with very little scaleforming material will often produce notable corrosion, especially if the feed water is introduced by a tube terminating at the boiler wall. The corrosion is generally less if the tube is prolonged to, or near, the centre of the water-mass. H.L.