IT 



3 

 U) 

 CO 



LU 

 OC 



I- 



< 



a. 



o 

 o 



0.12 



0.10 



0.08 - 



0.06 



0.04 



0.02 - 



0.00 1- 



10 



30 40 50 



TIME, MINUTES 



40 DAYS 



Fig. 9.4 Relation of physiological effects to carbon dioxide concentration and exposure period. [From Ref. (2)] 



ide within submersibles: Lithium hydroxide 

 (LiOH), a strong alkali; Baralyme (a weak 

 alkali); Soda Sorb (similar to Baralyme, but 

 contains small amounts of sodium hydroxide 

 and potassium hydroxide as an "activator"); 

 Soda lime (a low moisture Soda Sorb) and 

 potassium superoxide (KOj). The last of these 

 compounds, KOj, performs the dual role of 

 supplying oxygen as well as removing carbon 

 dioxide. 



The carbon dioxide "scrubber" system is 

 quite simple: A blower assembly forces cabin 

 air through one of the above compounds 

 which, in turn, removes carbon dioxide from 

 the air as it passes through. There is no 

 conformity vehicle-to-vehicle on the type of 

 fan, power of the fan motor, or volume or 

 configuration of the chemical bed. In the All 

 Ocean Industries vehicle an automobile vac- 

 uum cleaner is packed with KOj and the 

 vacuum cleaner motor operates directly off 

 the 12-volt battery. In DS-4000 a 1/50-hp 

 electric motor works directly from a 120-volt 

 supply to turn a drum type impeller which 

 forces air through a cannister containing 

 LiOH. In BE1\ FRANKLIN, 13 thin rectangu- 



lar panels containing LiOH were hung 

 throughout the vehicle and natural convec- 

 tion currents in the cabin served to pass air 

 through the panels. 



As far as certification or classification is 

 concerned, the system used to force cabin air 

 through the absorbent chemicals is left more 

 or less up to the individual. The ABS states 

 that the system should be designed with a 20 

 percent safety factor (i.e., 0.10 lb CO2 per 

 man-hr x 120% = 0.12 lb per man-hr mini- 

 mum). The MTS states that it is preferable to 

 use an AC induction motor rather than a 

 brush type DC motor to eliminate arcing 

 from the brush type motors. 



Probably the best and undoubtedly the 

 most recent summation of carbon dioxide 

 removal chemicals and their characteristics 

 is presented in the report of the JOHNSON 

 SEA LINK incident (6) in which two occu- 

 pants of the lock-out cylinder perished of 

 respiratory acidosis as a consequence of car- 

 bon dioxide poisoning. The following summa- 

 tion was written by one of the investigating 

 panel members, W. M. Nicholson, and is 



420 



