[PSUBS-MAILIST] Life support

[Sean T. Stevenson via Personal_Submersibles]

I'm sorry - I was short on time last night or I would have addressed the scrubbing as well. The design expected CO2 production rate is set by the rules in a similar manner. You need to look at the data sheet of your chosen scrubber media to find it's scrubbing capacity, efficiency, etc., then size the media volume accordingly (mission duration + 72 hours), and make sure that the flow path, flow rate / dwell time and so forth are sufficient to meet the rated capacity.  Also, you might want to separate mission and emergency scrubbers to conserve media.

Sean


On April 23, 2014 7:02:00 AM MDT, via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>Sean,
>
>Seems like your results on O2 are the same that I found. I have (2) 80
>cubic foot O2 tanks on my 2 man submarine. I am pretty sure most
>psubbers are not sticking to the mission time plus 72 hour requirement.
>I believe my figuring of 23 lbs of intersorb 812 per person is also
>close to correct and most psubbers are not carrying that as well. It
>seemed like a lot to me at the beginning based on my observations of
>other psubs, but I think it is correct.
>
>Thanks,
>
>Scott Waters
>
> 
>
>-------- Original Message --------
>Subject: Re: [PSUBS-MAILIST] Life support
>From: "Sean T. Stevenson via Personal_Submersibles"
><personal_submersibles at psubs.org>
>Date: Tue, April 22, 2014 8:13 pm
>To: Personal Submersibles General Discussion
><personal_submersibles at psubs.org>
>
>According to the ABS rules, per (11/35.3), you need sufficient oxygen
>for the mission duration PLUS the 72 hour reserve.
>
>Per (8/7.1), oxygen:  0.038 kg (0.084 lb) per hour, per person, at 1
>atm.
>
>x 72 hours emergency duration = 2.736 kg (6.032 lb) per person for 72
>hours.
>
>2.736 kg x (1000g/kg) x (mol O2/31.9988g O2) x (22.4 liters / mol O2) =
>1915 liters (@ STP, ideal gas assumptions)
>
>= 68 cubic feet oxygen per person for emergency reserve, additional
>oxygen appropriate to mission duration.
>
>Sean
>
>
>
>On 2014-04-22 17:52, swaters via Personal_Submersibles wrote:
>
>I have been trying to make sure I have suffecent life support for 72
>hours per ABS. It seems like the research varys a little. 
>
>I am showing
>
>*80 cubic feet of O2 per person
>
>*23 lbs sodasorb per person
>
>
>Is this right?
>
>Thanks,
>
>Scott Waters
>
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