BROMINE FROM SEA WATER STEWART 



165 



The original ground where these structures are located was exca- 

 vated to a depth of 9 feet or to a level which is about 5 feet above the 

 river at low tide. This was done to minimize the height that the sea 

 water would have to be pumped to the top of the blowing-out towers. 



A horizontal steel flume, which is semicircular in cross-section and 

 10 feet in diameter, extends between the two extraction units and con- 

 nects with the canal which brings in the sea water. Because the bases 

 of the towers and the area between them are below the canal level, the 

 flume is carried on steel supports so that it is at the same level as the 

 canal (pi. 3, fig. 2). The absorption towers are located at the end 

 of the flume which is nearest the canal. Hence, the water passes by 

 them on its way to centrifugal pumps which elevate it to the tops of 

 the blowing-out columns. Before entering the pumps, however, the 

 water flows through a traveling screen at the end of the flume. This 

 filters out any leaves or debris which may fall into the water after 

 it enters the canal or pond. 



CHLORINC INLCT ~* 

 ACIO INUT—~ 



Figure 7. — Diagram of bromine extraction unit. 



In each extraction unit the sea water is pumped to the top of the 

 blowing-out tower through a vertical 42-inch rubber-lined pipe. Near 

 the bottom of this, a 10 percent sulphuric acid solution is introduced 

 into the water through a group of small rubber-lined pipes. A short 

 distance higher the chlorine is introduced through similar rubber- 

 lined pipes. At the top of the blowing-out tower the water passes 

 through a series of large and small distributor boxes and pipes so that 

 it eventually is divided up into about 3,200 small streams. These flow 

 down through the tower, which is partitioned off into narrow cham- 

 bers extending the full width of the structure. These chambers are 

 filled with wood packing and are operated in parallel. A stream of 

 air is sucked up through the tower countercurrent to the sea water. 

 The bromine that has been liberated by the chlorine is thus blown out 

 of the sea water, and the latter passes out of the bottom of the tower 



