Re: [PSUBS-MAILIST] Live Support System was : Sgt. Peppers O2 consumption rate question.

[MerlinSub@t-online.de (Carsten Standfuß)]

Hi Pat, second part of the answer: 

The duration of a Sofnolime fill depends upon factors such as the
individual diver's/drivers CO2
production rate, water/air temperature, work rate and so on. In the
recent independent testing for
CE certification carried out at the Ministry of Defence Research
Establishment, Alverstoke, the
(Buddy-)Inspiration's (Rebrather) scrubber duration was 3 hours in cold
water (4 degrees C). The tests simulated a breathing rate of 40 litres
per minute (lpm) RMV, and a CO2 production rate of 1.6 lpm.

To refill the Scrubber requires 2.4kg of Sofnolime granules which
costs approx. £9. 
A.P.Valves are exclusive UK distributors of Sofnolime which is available
in
two grades: High grade [1 - 2.5mm] - which is used for the Inspiration
and
has 50% more absorbency than the lower grade [2.5 - 5mm].

(Source : www.apvalves.com/Inspfrmset.html)

The Air Volumen during breathing is : 
(source : Tauchen noch Sicherer, Prof.Dr.med.Ehm, page 72) 

Absolute silence, no work : 6 l/min
Going, slow       	  : 15 l/min
Swimming, slow            : 17,5 L/min
Swimming or diving        : 39-40 l/min

If we figure out that sitting in a small submarine is in the area of 10
l/min 
and the rebreather test use 40 l/min - it should be possible to work
with 
a 2,4 kg Sofnolime high grade (1-2,5mm) 40/10 = 4 x 3 hours = 12 hours. 

With Breathing rate 40l/min CO2 production of l,6 L/min (at 4 degree)
so with breathing rate 10 l/min should be equal to 0,4 l/min or x 60
= 24 liter/hour

that very near to : (Prof.Dr.med.Ehm)
 CO2 production of each person should be calculate with 20 Liter/hour
 for each person at 20°C and 1 bar atmosphere. 
= so this figures should be work. 

Conclusion : 
For each hour and each person in a small submarine the estimate figures
to
precalculate the L.S.S : 

15 liter O2 and 0,2 kg Sofnolime in High grade (1 - 2.5mm)

To convert translate some figures : 
1 Galleon = 3,7854 Liter
1 PSi     = 0,0689 bar

Any mistake possible, no gurantees, remarks welcome

Has anybody the density of Sofnoline ? It would be nice to calculate 
how much volume 0,2 kg Sofnolime is ..

Carsten


> Captain Nemo schrieb:
> 
> Carsten,
> 
> Approximately how long will 20 cubic feet of oxygen sustain you in
> your SGT. PEPPERS submarine, using an O2 replenishing / CO2 scrubbing
> life support system?  (A general estimation based on average
> consumption rate, temperature, and such will suffice.)
> 
> Thanks!
> 
> Pat