<html><head></head><body><p dir="ltr">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.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On April 23, 2014 7:02:00 AM MDT, via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<span style="font-family:Verdana; color:#000000; font-size:10pt;"><div>Sean,</div>
<div>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.</div>
<div>Thanks,</div>
<div>Scott Waters</div>
<div> </div>
<blockquote id="replyBlockquote" style="FONT-SIZE: 10pt; FONT-FAMILY: verdana; COLOR: black; PADDING-LEFT: 8px; MARGIN-LEFT: 8px; BORDER-LEFT: blue 2px solid" webmail="1">
<div id="wmQuoteWrapper">-------- Original Message --------<br />Subject: Re: [PSUBS-MAILIST] Life support<br />From: "Sean T. Stevenson via Personal_Submersibles"<br /><<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br />Date: Tue, April 22, 2014 8:13 pm<br />To: Personal Submersibles General Discussion<br /><<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br /><br />
<div class="moz-cite-prefix">According to the ABS rules, per (11/35.3), you need sufficient oxygen for the mission duration PLUS the 72 hour reserve.<br /><br />Per (8/7.1), oxygen: 0.038 kg (0.084 lb) per hour, per person, at 1 atm.<br /><br />x 72 hours emergency duration = 2.736 kg (6.032 lb) per person for 72 hours.<br /><br />2.736 kg x (1000g/kg) x (mol O2/31.9988g O2) x (22.4 liters / mol O2) = 1915 liters (@ STP, ideal gas assumptions)<br /><br />= 68 cubic feet oxygen per person for emergency reserve, additional oxygen appropriate to mission duration.<br /><br />Sean<br /><br /><br /><br />On 2014-04-22 17:52, swaters via Personal_Submersibles wrote:<br /></div>
<blockquote cite="mid:2tj9lxn8f38awyavaxvv7unp.1398206846763@email.android.com" type="cite">
<div>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. </div>
<div>I am showing</div>
<div>*80 cubic feet of O2 per person</div>
<div>*23 lbs sodasorb per person</div>
<div><br /></div>
<div>Is this right?</div>
<div>Thanks,</div>
<div>Scott Waters</div></blockquote>
<hr />
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