Zorg-Alien scrubber theory.

Freef

Writer-Gordon Henderson, the author of DDPLAN.

Here on Zorg, we abducted some humans to test your resistance to CO2 and the efficiency of our patented CO2 grabbing demon chamber.We took a human and connected a hose to them. The hose supplies gas and has one-way valves. The exit of the hose goes into a box. Inside this box are 1000s of little demons. These demons adore CO2. They will grab a passing molecule of CO2 and hang onto it for the rest of their lives. They can only hold one each. After the CO2 demon box there is another box with different demons inside - these count the number of O2 molecules you have used and replaces them.

We observed that humans when in a steady state consume the same amount of O2 per breath, regardless of the pressure we subjected them to. When given 100 molecules of our gas, they would use 4 molecules of our oxygen and turn this into 3 molecules of CO2 and 1 molecule of water vapour.So in the test, with 100 molecules of gas in the loop. The human push/pulled this through the box with the CO2 demons in it.

Every breath, 3 lucky demons grab a CO2 molecule each and are happy for the rest of their lives. We repeated this for many of your earth hours, pushing 100 molecules of gas through the CO2 box at a nice steady rate - the happy demon front line progressed linearly through the CO2 demon box until eventually they are all happy. At that point, the loop gas has some CO2 in it and we observed that the humans started to show signs of unease, panic and general ill-feeling.

They eventually died a rather uncomfortable death.

To continue our experiments, we abducted more humans and carried on, this time we subjected them to a pressure of 2 bar. This is the same as being under 10 metres of your water. There is now 200 molecules of gas in the loop, but the human still only uses 4 molecules of O2 and turns these into 3 molecules of CO2 and 1 water vapour. Each breathe pushes 200 molecules through the CO2 demon chamber, so the demons have to work faster to grab the CO2 molecules and die happy. Sometimes a front-line demon misses, but the 2nd line catches it OK.

This carries on and eventually all the demons are happy, then as above, the human dies painfully and horribly from CO2 poisoning.

We needed to do more experiments, so we continued with our abduction programme. Now we're testing to 90m. There are now 1000 molecules of gas in the loop, but as observed before, then humans still only take 4 molecules of O2 out and metabolises these into 3 of CO2 and one of water with each breath, However, the poor CO2 demons now have 1000 molecules of gas going through their chamber like a hurricane, and in those 1000 molecules there are still only 3 molecules of CO2! It's now very hard for the demons to catch a CO2 molecule and hang on to it!

The front-line demons have a really hard time catching the CO2 molecules and a lot more pass further down the line to be caught by the latter ones. Eventually, the front-line demons are full, but still the latter ones need to work to catch the CO2 and there will come a stage where there aren't enough latter ones who can catch the CO2 fast enough, so some will get through.

Eventually so many will get through that the human starts to notice it and dies horribly as before - even when there are still some unhappy and empty CO2 demons left.

Continuing our experiments with more abducted humans, we test again at 90m, but then we decide to ascend the human to some depth where the number of molecules in the loop is much less, so each breath the CO2 demons have more of a chance to catch the CO2 molecules left.Eventually, after 100's of trials, killing a great many humans every time, (And you should have seen our abduction budget! Off the scale!) we have come up with some rules for keeping humans alive and maximising the happiness of the CO2 demons. Our rules are many, long and complex but to simplify them for you humans we have reduced them to 3 simple rules.

Rule 1: You have 3 hours maximum.

Rule 2: For subsequent dives deeper than 20m: You must leave the bottom when the total time breathed through the system reaches 140 minutes.

Rule 3: For subsequent dives deeper than 50m: You must leave the bottom when the total time breathed from the system reaches 100 minutes.

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David.

Diving the mahogany rebreather.

decoweenie

Gordon Henderson, the author of DDPLAN.

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Freef

That was quick, many thanks.

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David.

Diving the mahogany rebreather.

granso

Very interesting indeed.
Let us see it from the point of view of the CO2 molecule.
1 bar: the 3 CO2 molecules see the demos, they flirt are caught by them.
2 bar: the 3 CO2 molecules see the same number of demos
10 bar: ditto

Now the question is: why should the probability density function of the CO2 molecule change if the number of O2 and N2 molecules increases?

Help me clarify this point, please.
Thank you in advance

nigelh

Consider yourself walking blindfold through a maze virtually alone trying not to touch the walls. How far do you get?

Repeat when you are packed in like Tokyo Subway commuters who just bounce off the walls, you are being carried along with the flow. You will get a lot further.

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nigelh

PaulTG2

Hello,

Try another analogy... an airport.

You have staff members around the terminal building. Their job is to catch kids in yellow tee-shirts -- kids which are part of the tours your company provideds. But, your staff can't move from their assigned stations. For them to grab one of the kids they have to be within 4 feet of the kids without anyone else between them.

Now you send 3 kids coming out of various airplanes along with 100 other people. Properly positioned the kids will naturally pass within 4 feet of a staff member with little likelyhood of others being in the way.

Now the same 3 kids coming out but there are 300 people.The chances of other people being in the way is much great.

With 3 kids coming out along with 500 other people things get crowded and it is very hard to have a kid pass within 4 feed without someone else being in the way.

Lots of ways to look at it. Various examples will help various people.


--p

granso

mmmhh yes, a part from the fact that molecules do not behave like people. They are not "tiny balls", but can be described as waves, not only particles. If you reason in terms of solid bodies, then a CO2 would be sorrounded by N2 and O2 particles. But I am not sure it's like that (this is what I was asking. Unfortunately I don't have here my physics books). A CO2 molecule is not even aware of a N2 molecule. It does not exist in terms of interactions.
I promise I'd do some research on that and let you know. I might be wrong but it just sounds strange to me.

Woz

Consider, if you will, a sack of spuds. In the sack there are 5 rotten spuds among the 25kg of good spuds. The sack is poured onto a conveyor belt which moves along at a steady speed. The conveyor belt has space for a potato sorter every metre. The potato sorters have to pick out and discard the 5 rotten spuds. With the bag of spuds, the potato sorters pick out the 5 rotten spuds every time.

Then consider a potato lorry. 20 tonnes of spuds with still only 5 rotten ones. The conveyor belt has to move faster to unload the spuds but to catch the rotten spuds, the conveyor belt is made longer to get more potato sorters along it. Eventually, the potato sorters get tired from sorting potatoes so wander off for a sit down. The rotten potatoes start to get through.

There is not enough physical room in the factory to fit in the massively long conveyor needed to pick out all of the rotten potatoes so they limit the time the conveyor operates to the mornings only. This way, the potato sorters can just about manage a shift before all being too tired to sort potatoes.

Think potatoes. It's the way forward.

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EBT

Im getting ready for the "burn the heretic" moments.... I've never really been comfy with the whole 'zorg' model. In your average gas sample the spaces between the molecules are huge, so this has never really made sense for me.

What does make sense for me is that the human body can only tolerate a certain PCO2, which means as we go deeper the % of allowable CO2 (usually 0.5% SEV) in our inspired mix would have to drop, in order to achieve the same PCO2. What this would mean in reality is that as the breakthrough starts, we'd be far less able to handle it at depth.

Even as Im typing this Im thinking that its time I re-read some scrubber research papers....arse.

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Padowan

I also struggle to totallt agree with the Zorg analogy. I like your statement Zak about the PPCO2 being the key factor, but if that was the driving factor, it doesn't explain why you get a thicker reaction front the deeper you are.

Is sorb totally porous? Are there perhaps miniscule (closed) air spaces in the granules that contribute to the effective surface area of the material as the gas flows through the bed - under (increased) pressure these spaces get compressed reducing the efficiency of the reaction, due to a reduction in effective surface area? Just an idle thought?

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