oms rebreather

PaulTG2

Hello,

I agree that what is holding back generational, or revolutionary change is simply numbers. There isn't enough demand/money in the market for organizations to spend the large amounts of resources needed to develop radical new rebreather technologies.

The current technology works well for the people using it, and there are darn few who need anything radically different. As a result we get people using existing technology and evolutionary changes to refine the design.

When I break it down there I only see two areas that are really open to revolutionary change for technical diving: Scrubber technology and Monitoring/control technology. The gas supplies and physical breathing loop have specific requirements based on physics and aren't likely to experience a revolutionary change but rather evolutionary changes that mix and match features to suit preferences.

Scrubber technology itself is really pretty good. The scrubber technology we have available now is pretty cost effective and efficient. Technology already exists to make it easier, more foolproof, and to prevent caustic cocktails (membranes, cartridge systems, traps). Evolutionary changes can certainly be made in these areas, but I doubt they'll solve any real, substantial problems.

A revolutionary step for scrubbers would be a practical CO2 to O2 converter. I expect that that is being explored to the best of existing knowledge and technology for other applications. Outside of that the only change I can see would be to make it last longer for a given size or make it cheaper.

That leaves monitoring/control as the real source of improvement, although the opportunities seem more evolutionary than revolutionary. Obviously everyone wants higher reliability electronics, better gas monitoring sensors for O2/CO2/He/other, direct measurement of scrubber duration remaining, and better failsafe designs for gas injection. There is obviously more to do in the eCCR world than the mCCR world.

I don't consider decompression tracking to be rebreather technology. I realy is an outside technology grafted onto the rebreather for convenience. It isn't a necessary part of a rebreather.

The real revolutionary, and market, opportunity is in moving outside the technical diving market and into the mainstream rental strap-it-on-and-dive market. This requires major changes in design philosophy, electronics/controls, and, most importantly, overall durability. That is hindered by the early adopters who will reject most of the technology that makes moves in those directions as they also tend to limit applications to areas outside the early adopters use areas.

Hmmm... interesting....


-p

SeaBass

My understanding is that in other high growth industries new technology is eventually accepted (by target market), standardized and mass produced bringing the cost down.

It is my guess that this is where Draeger pioneered and failed. It attempted to sandardize a not fully developed/accepted technology. As a result it was not fully embraced by technical divers or mainstream.

The understanding I get from Dave's comment regarding "this generation" is that it has basically been accepted (by technical divers) and standardized (conceptually) meeting it's evolutionary end. This would imply that it could be mass produced (not at it's current price point) however the technical diving community's demand is basically low (how many members of Rebreather World are there?).

So I agree the real opportunity is outside the technical diving market but has yet to be fully accepted, developed and standardized.

--SB

Dave Sutton

I deleted your (many) good points, but challenge the above: Chemical scrubbing is the huge achilles heel of current rebreathers. Cryo-scrubbing is the next step... infinite duration, zero consumables save for the cryo (which would also be the gas source), zero caustic coctails, etc. Think out of the box, man!

Rebreathers will eventually go two divergent ways: One to the common-man, who can use the black-box without knowing or caring what goes on inside, and technical 'super rebreathers' using cryogenics, non-chemical scrubbers, near infinite durations, etc. The present state of the art is but a flash in the pan, my friends.


Dave

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"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

trob09

The present state may be a flash in the pan, but I suggest it is a flash with a slow burn. Technology just doesn't move that fast. Look at the auto industry. 50 years ago they said we'd have flying cars by now. Other than on James Bond, I haven't seen one.

While there have been improvements in safety, power-generation efficiency, materials use and general technology enhancements, cars are still fundamentally the same as they were 50 years ago. The auto industry has billions to invest in R&D, the rebreather industry has???

The rebreather I dive at the end of my diving career may be somewhat improved from what I dive now, but I will be very (pleasantly) surprised if it takes on the paradigm shift you describe.

chunter

I totally agree. There have already been attempts at cryogenic units, and I doubt that will be the answer. With such a limited market, there is little or no reason to build anything that works better that what is currently available. Even the US military has decided to upgrade the Mk 16 electronics rather than redesign the whole loop...and that unit is 20 years old (and still the best unit out there).

__________________
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"Hobgoblin is a cool word."
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SeaBass

Ok for those of us who never heard the term "cryogenics" here is what my limited research on the subject revealed.

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Cryogenic Separation is a distillation process that occurs at very low temperatures close to -170 degrees celsius.

At −78.51° C or -109.3° F, carbon dioxide changes directly from a solid phase to a gaseous phase through sublimation, or from gaseous to solid through deposition. Solid carbon dioxide is normally called "dry ice", a generic trademark.

Before separation can occur, there are specific operation conditions that must be achieved. Distillation requires two phases, gas and liquid. CO2 must be very cold for this to happen.
These conditions are achieved via compression and heat exchange; cold air exiting the column is used to cool the gas entering it.
--------------------------------------------------------

Although it *sounds* cool this process seems to be the the more difficult of the other common CO2 seperating technologies.

Dave are you under and NDA on this?

--SB

mverick

Toyota Prius claimed mileage is 51 to 60. But people driving it are getting 34 to 45. Still good mileage. But a Hybrid?

A VW jetta Diesel gets 45-55 and has for a long time. Yet, it don't have a hybrid badge.

Just because people say it's a new efficient toy don't mean it is more efficient then you already have access too.

I agree some time there is going to be a major manufacturer come in and blow the Rebreather market away. No more home made parts. Cost all of $200 for the whole unit in parts. Sell for around $3000.

It could actually be next year. Just gotta get the Major players to jump in the pond. They have the ability. Look at what a Cochran or Oceanic or Mares or ScubaPro computer does compared to a HSExplorer or a Vr3.

They can write the code. They can make them waterproof. Best of Injection molding tech and the suppliers who would love the work. They have the ability without any doubts in my mind. They, just don't want to. To small a market.

ScubaPro, Mares, Oceanic could have a unit up and diving in 1 year easy. If they wanted to. But, you don't see one.

OMS, Halcyon, DiveRite are all minor players. They can't put the Big money down and don't have the code writers.

I think we'll see cryo when Flash Gordon is reserected. LOL...

But, all it takes is one advancement. Kevlar was an accident. Vulcanizing was an accident. Lot of accidents that made huge leaps in Technology. Just gotta wait for the next accident.

Dave Sutton

Yup. Exactly. I just tossed the cryo-scrubber out as a paridigm shift example, just let your mind wander and consider that things do change.

Ya'll might want to look at this, though. "PLSS" means "Personal Life Support System", meaning "Man Worn", not "vehicle mounted". We're talking BACKPAK here, guys.....


NASA Technical Reports Server

Short quote:

"A breadboard cryogenic carbon dioxide scrubber (Cryo Scrubber) for a closed loop cryogenic PLSS was developed, designed, and tested, and a conceptual design suitable for a PLSS was developed based on the results of the breadboard testing. The Cryo Scrubber freezes CO2 and other trace contaminants out of expired vent loop gas using cooling available from a liquid oxygen (LOX) based PLSS. The device is continuously regenerable, with solid CO2 being removed from the cold freeze-out surfaces, sublimated, and vented overboard. Duration is limited only by the supply of LOX stored in the PLSS. Simplicity, reliability, and operability are universally important criteria for critical hardware on long duration Lunar or Mars missions. The Cryo Scrubber has no moving parts, requires no additional consumables, and uses no electrical power, contributing to its simplicity and reliability. It is easy to use; no operator action is required to prepare, use, or shut down the Cryo Scrubber, and it does not require charging or regeneration. The versatility of the concept allows for operation on earth, the moon, and Mars, and in microgravity."


Dave

(looking at his cryogenic SCUBA (Kryolang) sitting on the shelf across my study, BTW....
I'm gonna dive that sucker one year! ) See: Cryo Pjotrr


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__________________
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"All animals are equal, but some animals are more equal than others"


Professional Small Boy: Never Successfully Cubicled.

mverick

Sounds like cold fusion to me. No recharging, No consumables, No Electricity. Hmmm... LOL... Should be able to power a 65 GTO with True Spokes too then. Love to see that driving around on Mars Mission. Pickin up some Martian hotties..

But, never know.

I've seen a kryolang before. Kinda cool. Come on, I wanna see somebody dive one.

Just don't say "Watch This" right before you use it. LOL... That's the last words of a Red Neck. LOL... Which has gotten me into trouble a bunch of times. LOL.... As I said it.

What was the duration on those? I know they were tested. But, so was nuclear fallout on St. Louis. Sprayed from planes for testing. Nice of our Government wasn't it..

trob09

The happy accident certainly can present a path to a new level. I'm just skeptical that we'll see that accident lead to accessible technology advancement for commercial rebreathers in our diving lifetime. The odds suggest that it won't happen.

Sure, we'll see lots of improvements that lead to better, safer rebreathers. But a paradigm shift? unlikely. There's simply not enough ROI in exploring out-of-the-box concepts to increase the odds that a happy accident will happen and lead to a fundamentally new rebreather.