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Hi Emile,
Most of the information out there on scrubbers
deals with rebreathers & medical systems that push through
higher concentrations of CO2 than we do in subs
(read below)
Below is an email I sent to Molecular products
LTD.
I couldn't find there other reply with a more
extensive answer, based on the parameters I provided them.
They are very helpful & have programs for
calculating out your requirements & the most efficient way of doing
things.
They produce the sofnolime brand
Regards Alan
----- Original Message -----
From: Philip Heyes
Cc: Natalie
Sewell
Sent: Tuesday, June 15, 2010 9:33 PM
Subject: Enquiry Dear Alan, Ref your enquiry on Sofnolime® 797: Hi, I\'ve bought your 797 grade Sofnolime for the purpose of
controlling CO2 in a small 1 atmosphere submarine. All the information I\'ve
found reguarding dwell time of air through the absorbant refers to rebreathers
& closed circuit medical use wich would deal with concentrations of 4% CO2.
I would be putting air through at typically less than 1/2% CO2. Does this mean I
can have less dwell time in the absorbant? I need to move larger volumes of air
to control levels than in a closed circuit. Any advice on flow levels thanks. I
am also asking this question on behalf of a number of other submarine
enthusiasts. Thanks Regards Alan You’re correct in your assumption that absorption in larger
volume has different constraints on dwell time. To be able to answer the
question fully we’d need to know the air volume in the submarine, or compartment
if it’s a rescue situation. Your anticipation of ½% is low for normal breathing
unless you mean you want to keep the CO2 below this level. Please confirm.
Otherwise we can make an assumption. Bear in mind expired air in breath
comprises approx 5% CO2 by volume AND given the rate can be over 25 litres of
air breathed per person per minute – 1.25 litres of CO2 per minute
produced. So what we need to know is: ·
Volume of free air ·
Number of persons in the compartment and expected
activity level ·
Limits on the practical flow rate you can achieve
– so we can work out air changes. With this information we can give you an estimate of the
amount of Sofnolime required and its longevity. You’ll also, I’m sure, have considered replacing the 5%
Oxygen taken by each person per breath nd replaced it from an oxygen, rather
than air supply, unless that’s unlimited. Best regards Phil Phil Heyes Business Development
Manager Molecular Products
Ltd. Mill
End Tel: +44 (0) 1371
832210 Mobile: +44 (0) 7738
995261 E-mail:
psh@molprod.com Web:
www.molecularproducts.com P
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