166 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1934 



through exit flumes to the river and thence into the ocean about 12 

 miles south of the intake. Plate 4, figure 1, shows a view of the 

 exit flume. 



The treatment of the sea water on its way to the blowing-out towers 

 is regulated from the nearby control laboratory. Meters on a wall of 

 the laboratory continuously show both the pH of the acidified sea 

 water and its oxidation potential with respect to bromine liberation. 

 Valves in the sulphuric acid and chlorine lines which lead to the 

 42-inch vertical mixing pipes are operated by hand from the control 

 laboratory. At a later date it is probable that the control of these 

 valves will be made automatic. Signal lights above the meters also 

 indicate whether the condition of the treated sea water is correct for 

 the blowing-out towers. 



The chlorine which is used in oxidizing the sea water is obtained 

 from cylinders having a capacity of 1 ton. A group of 16 of these 

 is placed in each of 2 wooden compartments. These are kept at a 

 temperature of not less than 70° F. The cylinders are connected to 

 the chlorine line and their contents, in liquid form, flow to the chlorine 

 vaporizer. This is a steam- jacketed iron pipe and is located adjacent 

 to the control laboratory. 



The sulphuric acid is delivered to the plant in the concentrated 

 form, but it is diluted to a 10 percent solution before it is added to the 

 sea water. This dilution is accomplished in two rubber-lined tanks, 

 16 feet in diameter and 10 feet high. These are located adjacent to 

 the control laboratory. 



In each extraction unit the air from the blowing-out tower is 

 drawn through its adjacent absorption tower by three fans which 

 are located on a concrete platform at the end of the unit. The air, 

 just before entering the fans, passes through a small wood-filled 

 chamber which catches any spray of soda ash solution that might 

 otherwise be carried out of the system. 



In the absorption tower the bromine is removed from the air by a 

 soda ash solution to form a dissolved mixture of sodium bromide and 

 bromate according to the formula : 



3NaoC03 + 3Bro -^ SNaBr + NaBrOs + SCO, 



The absorption towers are built on reenforced concrete arches which 

 elevate their floors so as to permit gravity flow of the dissolving 

 liquor into tanks which are located at their bases. This construction 

 also makes possible the detection of any leakage which might take 

 place in the tower bases at any future time. 



Each absorption tower is divided into nine chambers which are 

 connected in series so that the air, passing in at the end adjacent to 

 the blowinoi;-out tower, follows in succession through these absorbing 



