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Butane used as refrigerant in home air conditioning installation
March, 1937.]
CURRENT TOPICS.
411
has been a continuous search on the p a r t of electric furnace builders for a heating element which could be run at t e m p e r a t u r e s higher t h a n those possible with nickel chrome materials. Recently the A. O. Smith Corporation became interested in this problem and Dr. S. L. HOYT and Mr. R. ARCHER with others discovered an alloy of iron, chromium and a l u m i n u m which was a s o m e w h a t radical departure from previous productions. I t proved quickly to h a v e outstanding characteristics when used at elevated t e m p e r a tures. As soon as reasonable quantities of wire were available test furnaces were built on a semi-commercial scale. T w o such furnaces are still in operation and on one of these a Telechron hour counter indicated I8,7oo hours of operation at all t e m p e r a t u r e ranging from 2ooo to 23oo deg. and including several overheating cycles where the t e m p e r a t u r e was as high as 2500 ° F. The new alloy is known as " Alloy IO." Of all the properties of this new alloy the specific resistance of Iooo ohms per cir. rail ft. is of special interest. This is a p p r o x i m a t e l y 50 per cent. greater than nickel c h r o m i u m grades and permits with equal a m p e r e ratings an increase of 50 per cent. in the power liberated b y the element. An i m p o r t a n t characteristic which gives " Alloy Io " high resistance to destructive oxidation is an a l u m i n u m oxide which forms initially on the surface of the wire when heated to operating temperature. This oxide is practically impervious to further attack, either by oxidizing or reducing gases, and makes it possible to use the alloy under varying conditions of furnace c h a m b e r atmospheres. T h e use of this alloy should be of interest in such applications as the heat treating of metal products and ceramic ware, the t r e a t m e n t of high speed steels, and for firing of p o t t e r y and china ware. R. H. O.
Butane Used as Refrigerant in Home Air Conditioning Installafion.--A. S. JAMES. (National PetrOleum News, Vol. X X I X , No. 2.) Normal butane, now in d e m a n d as a liquefied petroleum gas because of its heating qualities has proved itself desirable in just the opposite role---that of refrigerant in an air-conditioning unit. Practical demonstration of this is to be found in the Tulsa home of Paul M. Raigorodsky, where an experimental unit built more t h a n a year ago has developed into an economical and efficient system so successfully t h a t an application has been m a d e for a patent. T h e installation's design is similar to the conventional a m m o n i a absorption system used in the m a n u f a c t u r e of ice, except t h a t b u t a n e and octane are used instead of a m m o n i a and water for the circulating mediums. With b u t a n e it is possible to obtain t e m p e r a t u r e s in the e v a p o r a t o r as low as 35 to 4 ° deg. when oper-
412
CURRENT TOPICS.
[J. F. I.
ating the e v a p o r a t o r at atmospheric pressure. A h y d r o c a r b o n having the characteristics of octane is used for absorbent. This liquid has a relatively low boiling point, which enables the still to be operated at a t e m p e r a t u r e around 25 o° F. This low t e m p e r a t u r e does not cause the absorbent to disintegrate and coke the pipes. These two hydrocarbons also give a high degree of separation when using only single flash vaporization, thus eliminating the necessity of an elaborate fractionating a p p a r a t u s and reducing the fuel consumption to a m i n i m u m . T h e whole unit with the exception of auxiliary e q u i p m e n t is located on a concrete foundation a b o u t 6 ft. b y I2 ft. T h e only moving parts are small pumps. Airconditioning is accomplished b y continuously chilling and circulating the air in the rooms. A s t e a m boiler in the system, for furnishing heat to separate the b u t a n e and the octane, is used, during m o n t h s when heat is required, as a hot w a t e r heater. T h e water is p u m p e d through a fin t y p e air cooler which then becomes an air heater and the heated air is circulated around the house. R. H. O.
Hot Well Water Cooled for Use in City Distribution System.-Six years ago the city of Riverside, Calif., added to its water supply s y s t e m an artesian well which produced 2000 g.p.m. T h e w a t e r in all respects was up to s t a n d a r d requirements except t h a t its t e m p e r a t u r e was I IO deg. F. P a r t of the flow was p u t into the city w a t e r supply along with cool w a t e r from other wells b u t the result was to raise the average t e m p e r a t u r e to an objectionable degree, so the hot well w a t e r had to be substituted b y cold w a t e r from another source. Recently it was decided to employ an evaporation process to cool the hot w a t e r sufficiently to permit using it in the city system. A cooling system was built, designed on the principle of evaporating w a t e r in contact with tubes containing the hot water. A concrete basin 25 X I75 ft. in plan with walls I2 in. high was built. Extending the length of this basin and some 6 ft. above it are 42 thin galvanized iron tubes 2 in. in diameter arranged in seven vertical tiers of six tubes each. These cooling tubes are served at one end from a I2 in. header bringing the hot w a t e r from the well via a booster pump. At the other end the tubes discharge into a I2 in. header leading to the city mains. T h e circulating water is t a k e n from the hot well and goes first to the concrete basin in which float valves maintain a depth of a b o u t 4 in. F r o m two s u m p s in the concrete basin, p u m p s circulate the cooling w a t e r so as to keep the surface of the cooling tubes covered with water. T h e transfer of heat from the tubes to the circulating w a t e r plus evaporation cools the well water
(Engineering News Record, Vol. I I8, No. 4,)
CURRENT TOPICS.
411
has been a continuous search on the p a r t of electric furnace builders for a heating element which could be run at t e m p e r a t u r e s higher t h a n those possible with nickel chrome materials. Recently the A. O. Smith Corporation became interested in this problem and Dr. S. L. HOYT and Mr. R. ARCHER with others discovered an alloy of iron, chromium and a l u m i n u m which was a s o m e w h a t radical departure from previous productions. I t proved quickly to h a v e outstanding characteristics when used at elevated t e m p e r a tures. As soon as reasonable quantities of wire were available test furnaces were built on a semi-commercial scale. T w o such furnaces are still in operation and on one of these a Telechron hour counter indicated I8,7oo hours of operation at all t e m p e r a t u r e ranging from 2ooo to 23oo deg. and including several overheating cycles where the t e m p e r a t u r e was as high as 2500 ° F. The new alloy is known as " Alloy IO." Of all the properties of this new alloy the specific resistance of Iooo ohms per cir. rail ft. is of special interest. This is a p p r o x i m a t e l y 50 per cent. greater than nickel c h r o m i u m grades and permits with equal a m p e r e ratings an increase of 50 per cent. in the power liberated b y the element. An i m p o r t a n t characteristic which gives " Alloy Io " high resistance to destructive oxidation is an a l u m i n u m oxide which forms initially on the surface of the wire when heated to operating temperature. This oxide is practically impervious to further attack, either by oxidizing or reducing gases, and makes it possible to use the alloy under varying conditions of furnace c h a m b e r atmospheres. T h e use of this alloy should be of interest in such applications as the heat treating of metal products and ceramic ware, the t r e a t m e n t of high speed steels, and for firing of p o t t e r y and china ware. R. H. O.
Butane Used as Refrigerant in Home Air Conditioning Installafion.--A. S. JAMES. (National PetrOleum News, Vol. X X I X , No. 2.) Normal butane, now in d e m a n d as a liquefied petroleum gas because of its heating qualities has proved itself desirable in just the opposite role---that of refrigerant in an air-conditioning unit. Practical demonstration of this is to be found in the Tulsa home of Paul M. Raigorodsky, where an experimental unit built more t h a n a year ago has developed into an economical and efficient system so successfully t h a t an application has been m a d e for a patent. T h e installation's design is similar to the conventional a m m o n i a absorption system used in the m a n u f a c t u r e of ice, except t h a t b u t a n e and octane are used instead of a m m o n i a and water for the circulating mediums. With b u t a n e it is possible to obtain t e m p e r a t u r e s in the e v a p o r a t o r as low as 35 to 4 ° deg. when oper-
412
CURRENT TOPICS.
[J. F. I.
ating the e v a p o r a t o r at atmospheric pressure. A h y d r o c a r b o n having the characteristics of octane is used for absorbent. This liquid has a relatively low boiling point, which enables the still to be operated at a t e m p e r a t u r e around 25 o° F. This low t e m p e r a t u r e does not cause the absorbent to disintegrate and coke the pipes. These two hydrocarbons also give a high degree of separation when using only single flash vaporization, thus eliminating the necessity of an elaborate fractionating a p p a r a t u s and reducing the fuel consumption to a m i n i m u m . T h e whole unit with the exception of auxiliary e q u i p m e n t is located on a concrete foundation a b o u t 6 ft. b y I2 ft. T h e only moving parts are small pumps. Airconditioning is accomplished b y continuously chilling and circulating the air in the rooms. A s t e a m boiler in the system, for furnishing heat to separate the b u t a n e and the octane, is used, during m o n t h s when heat is required, as a hot w a t e r heater. T h e water is p u m p e d through a fin t y p e air cooler which then becomes an air heater and the heated air is circulated around the house. R. H. O.
Hot Well Water Cooled for Use in City Distribution System.-Six years ago the city of Riverside, Calif., added to its water supply s y s t e m an artesian well which produced 2000 g.p.m. T h e w a t e r in all respects was up to s t a n d a r d requirements except t h a t its t e m p e r a t u r e was I IO deg. F. P a r t of the flow was p u t into the city w a t e r supply along with cool w a t e r from other wells b u t the result was to raise the average t e m p e r a t u r e to an objectionable degree, so the hot well w a t e r had to be substituted b y cold w a t e r from another source. Recently it was decided to employ an evaporation process to cool the hot w a t e r sufficiently to permit using it in the city system. A cooling system was built, designed on the principle of evaporating w a t e r in contact with tubes containing the hot water. A concrete basin 25 X I75 ft. in plan with walls I2 in. high was built. Extending the length of this basin and some 6 ft. above it are 42 thin galvanized iron tubes 2 in. in diameter arranged in seven vertical tiers of six tubes each. These cooling tubes are served at one end from a I2 in. header bringing the hot w a t e r from the well via a booster pump. At the other end the tubes discharge into a I2 in. header leading to the city mains. T h e circulating water is t a k e n from the hot well and goes first to the concrete basin in which float valves maintain a depth of a b o u t 4 in. F r o m two s u m p s in the concrete basin, p u m p s circulate the cooling w a t e r so as to keep the surface of the cooling tubes covered with water. T h e transfer of heat from the tubes to the circulating w a t e r plus evaporation cools the well water
(Engineering News Record, Vol. I I8, No. 4,)