Quote: (Originally Posted by silent running)
Hi mverick, the screen is a bit flexable and does bow out if packed really tight. I think the plastic structure is not flexing much in that situation. I would guess that it's designed that way as the scrubber needs to stay a certain height to maintain a seal at the top/inlet and the head.
As for thermal conductivity, it seems to me that you'd have to heat up a piece of metal to a higher temperature just to get it to hold a lower temp. In other words, I don't think the scrubber housing ever gets up to the temp of the gas in the jacket, no matter what it's made of. It's more a matter of which material loses heat at the slowest rate than retaining it... -Andy
You have 2 heat sources. The person breathing and the scrubber. Scrubber being hotter.
Be intresting to test loop temps.
The plastic will get up to temp. Whatever the loop temp is plus some. On metal it will quicker. Because it holds the scubber material it has direct contact.
Don't have to heat up metal to a higher temp. And, the scrubber is Hot. Without question. That's why all the condensation on the bucket. But, between the bucket and the scrubber you have an airspace. Which is a great insulator. Thing taking heat away is the air flow through the scrubber. Which is heated through the scrubber.
In to out will be more efficient. Because your not pulling the exhale heat out on the bucket wall before scrubber. I just don't think the scrubber material matters. Out to in you pull moisture out. Then run it through the heated scrubber where it heats back up so it will not condense as easy. Which would be why not noticeable on the cells. You're re heating the air. You do loose some scrubber efficiency though.
You want to loose heat in a rebreather but not loose it in the scrubber. Just want to do it where you want. Otherwise, It would be cooking you from the inside out.