Breathing Gas Processing: Overview

(Update 11.03.2023: structure renewed) This article is intended to define the concept for ensuring the appropriate habitat atmosphere to be used in the Calamar Park modules.

It is divided into the following sections:

Guide Value for Electricity Costs
Oxygen
Oxygen Demand of a Human Being
Oxygen Availability
Carbon Dioxide
Normoxic Gas Mixtures (Normox)
Air Supply from the Surface
Carbon Dioxide Scrubbing by Soda Lime
Carbon Dioxide Scrubbing by Monoethanolamine (MEA)
Carbon Dioxide Scrubbing by Sea Water
Photosynthesis
Water-Air Membrane
Oxygen by Electrolysis

Our extensive analysis and proposals are part of the design manual.

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Mike

6 years ago

Well, there are more points why compressed air tanks should be stored outside. First is simply space, because the internal space is precious (Have you ever spent a week in a camping trailer?). Second, if the tanks have to be moved in and out for refill, that’s a hard and time consuming work. Especially if there is an air lock in between. However, I do not agree with the statement that compressed air tanks add a risk to the habitat when stored inside. Technically there is no difference between a storage tank for compressed air and a SCUBA tank, except… Read more »

Mart

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Reply to Mike

6 years ago

Right, I will add the space and refill issue to the article. I could not find any source about the reasons of keeping storage tanks outside the habitat, but I assumed, that there is a risk during the filling process (not when it’s already filled), because of the rising temperature, the temperature difference inside and outside the tanks, handling of the tanks, and maybe problems with the valves. But I might be mistaken. On the other hand, there is no reason to keep the tanks inside the habitat.

Mike

6 years ago

Up to now, I have not filled a tank under water. But in a dive-shop in Greece, I have witnessed a filling operation in a water pond, to cool at least the lower half of the tank during filling. Don’t think there is a temperature issue. I can imagine two different situations: a) Empty tanks are replaced by full tanks Suggest to bring the tanks with already attached first stage and inflator hose. There is no issue to connect/ disconnect inflator hoses under water, so we could use this to connect to the air system of the habitat. b) A… Read more »

Mart

Author

Reply to Mike

6 years ago

Exactly, we have these two alternatives. But to bring each tank to the habitat would require a diver, who is dedicated to that job only. That’s not it. But keeping one end of the high pressure hose on the surface buoy, so that the fixed tanks can be refilled from there without moving the storage tanks, would be a great solution, at least for stage 2 of the project. The atmosphere of the initial habitat (stage 1) could be renewed by a constant air flow from a compressor on the support vessel, whenever there are divers inside the habitat. For… Read more »

Mike

6 years ago

Both alternatives have their Pros and Cons. There is no rental market for surface buoys, but you can rent SCUBA tanks and 1st stages. Supporters and volunteers might want to move the air tanks while visiting the habitat.
On the other hand, if you are planning an archaeological expedition, you do not wand to rely on luck and surface buoy is perfect.

Mart

Author

Reply to Mike

6 years ago

Divers, who want to enter the station, unfortunately will have to pay (we won’t get rich of it, but we do have to earn at least a bit to pay some bills). Surely we will need volunteers for many situations there, but for repeated procedures we will need our own support divers, no way out. Right, there are no buoys for our needs from the shelf. But I was thinking to build it by ourselves anyway, since we need a navigation light on the surface. All we have to do is to find a solution to fix the High Pressure… Read more »

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