How Much Refrigeration Is Required to Cool Air? - C&EN Global

This chart, developed by A. Lewis, chief mechanical engineer of the Commonwealth Works Department of Australia, makes it easy to determine the amount ...
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CHEMICAL AND CHEMICAL ENGINEERING NEWS

VOL. 18, NO. 5

Wall Street of Chemistry

How Much Refrigeration Is Required to Cool Air?

CONTINUED FROM PAGE 2 1 2

W. F. Schaphorst 45 Academy St, Newark, N. J.

and contingencies, of $7,847,483 or $2.04 per share on common. This compare* with $6,963,632 or $1.81 a share in 1938. The company paid during the year diwdends equal to $2.00 per share.

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United Carbon Co. and subsidiaries show net profit of $1,518,266 or $3.81 a share on coir :*.-r.-.4 for the year ended December 31 1939. This compares with $1.505,874 c. $3.78 a share during 1938. Sales volume during the year registered a marked increase but depressed prices hail their effect on profits.

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U. S. Gypsum Co. and subsidiaries fur the year ended December 31, 1939, report "net income of $7,365,847 after depreciation, depletion, federal income taxes, etc., equal after 7 per cei.t preferred dividends to $5.71 a share ( par $20 ) on common. This compares with $4,725,497 or $3.50 a share in 1938. The chairman of the board reports expectation of a satisfactory level of business for the next few months. Vanadium-Alloys Steel Co. and suk>sidiarv for the six months ended December 31, 1939, report net profit of $434,995 after interest, depreciation, and f«nierai and state taxes, equivalent to $2.17 a share on no-par common. For the fiscal year ended June 30, 1939, net profit of $90,890 or 45 cents a share was reported. New business received since the first of January is reported to have shown no decline from the fourth quarter of 1939. Vanadium Corp. of America has called for redemption on March 15 its outstanding funded debt, consisting of $2,316,000 debentures and $600,000 notes. Westtnghouse Electric & Manufacturing Co. reports net profit for the three months ended January 31, 1940. of $4,379,450, compared with $2,064,558 for the comparable period of 1939. Profits declined m January below November and December, in spite of increase in new orders e^®

Thermometer of Paper A NEW chemically treated paper called "Sure-Temp", manufactured by the Nashua Gummed and Coated Paper Co., Nashua, Ν. Η., which changes from white to deep blue when the temperature rises above a certain point, is an inex­ pensive, convenient replacement for more expensive and damageable pyrometers and steam-pressure gages. It has an opaque white coating of a material which melts sharply at a definite temperature, indicating positively by change in color that the surface with which the paper is in contact has reached that degree of heat. It can be made for controlling many temperature limits. Designed originally for use in laundries, it is finding wide application.

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Air Temp. Degrees Fàhr. This chart, developed by A. Lewis, chief mechanical engineer of the Com­ monwealth Works Department of Aus­ tralia, makes it easy to determine the amount of mechanical refrigeration or ice necessary to cool any amount of air. To apply the chart find the temperature of the air, using the figures at the bottom of the chart. Run upward on the line representing temperature to the point where it cuts the corresponding humidity curve for the air. Horizontally to the right is the figure corresponding to tue heat content B. t. u. per 1000 cubic feet. To reduce air temperature 10°, run upward on the reduced temperature line to the desired humidity and then hori­ zontally to the right and deduct the newly determined figure from the former. The difference is the number of B. t. u. that must be removed from the air. The distance between the two figures, determined with a pair of dividers, placed alongside the "vertical scale", gives the refrigeration required for 24 hours. For example, how many tons of ice will be required per day to cool 1000 cubic feet of air per minute having an

original temperature of 100° F. and 40 per cent humidity to 90° temperature and 20 per cent humidity? This problem happens to be easy be­ cause the intersections coincide, giving 3000 B. t. u. - 2000 B. t. u. ~ 1000 B. t. u. Since the distance on the chart from 3000 to 2000 is slightly greater than the vertical scale distance representing 4 tons, the answer is almost 5 tons of ice per 24 hours. Dividing 1000 B. t. u. by 218 gives 4.0 tons as the exact answer. For any other quantity of air, results are directly proportional. Thus for 2000 cubic feet of air per minute, the require­ ment would be 4.6 tons X 2 - 9.2 tons of ice per day. e^© A NEW bowling ball, made to A. B. C. regulations and reported to be a true sphere to within 0.0005 inch, is being manu­ factured by the Manhattan Rubber Mfg. Division, Passaic, N. J , as a result of ex­ tensive research in modern rubber chemis­ try- Balls are made of a combined hard rubber and plastic composition by s new procesb which is claimed to provide longwearing qualities with accuracy.