New book on scrubber canisters by John Clarke

[rjack321]

Yup, I'd say he has done the diving community a great service by publishing his work through the blog and now this book, sharing info that would otherwise be harder to access in (admittedly also excellent) NEDU reports. I hope people realize the ressources and years of cutting edge research on this very topic that back up John Clarkes expertise. Just got my book, looking forward to study it!

So far so good. It's fairly math dense and slow going.

Didnt realize that that variance around scrubber duration was so much higher in really cold water. It makes sense, just hadnt seen it articulated before.

 

[rsingler]

Received not one, but TWO copies of the book for Christmas (both wife and son)! It's a slow read, but excellent!
DM me if you want my second copy (new) for $35. Five bucks off retail and I'll pay shipping.

 

[rsingler]

Bump. $30, and I'll pay shipping. Yeah, I know. This isn't the Classifieds. But who'd ever go looking for "Breakthrough - Revealing the Secrets of Rebreather Scrubber Canisters" there?

 

[BlueTrin]

Bump. $30, and I'll pay shipping. Yeah, I know. This isn't the Classifieds. But who'd ever go looking for "Breakthrough - Revealing the Secrets of Rebreather Scrubber Canisters" there?

I guess you won’t pay the shipping to London?

 

[rsingler]

SOLD - thanks!

 

[rjack321]

So I finished the book... FYI its written at what I would call the advanced engineering or respiratory physiology graduate student level. It's heavy on calculus, stochasticity, and probability - like very heavy. You can still get value from the text and figures at a more superficial level, but it's a very technical monograph. If you understand Matlab or work in Wolfram Mathmatica, you will feel at home in this book. I had no problem with the probability and statistics in there as I use those in my day to day work. The calculus was wayyyyy in my distant past and I had to gloss over.

Many of the concepts about how CO2 is absorbed by lime, how heat is created and propagated in scrubbers, how cold water impacts scrubbers, how lime size and particle distribution affects 'work of breathing', gas density and density limits, and related topics we discuss here are included. But that coverage is not even. The section on CO2 absorption was the longest. Cold water and scrubber insulation also got considerable pages. Particle size and distribution was discussed but not quite as extensively. Work of breathing and gas density got covered but not nearly so exhaustively. It's a bit of a history of the author's work at NEDU and he recently retired so it feels like the topics that got the most attention over his career got the most attention in the book.

Was worth reading but probably not "required" reading for CCR divers.

 

[BlueTrin]

So I finished the book... FYI its written at what I would call the advanced engineering or respiratory physiology graduate student level. It's heavy on calculus, stochasticity, and probability - like very heavy. You can still get value from the text and figures at a more superficial level, but it's a very technical monograph. If you understand Matlab or work in Wolfram Mathmatica, you will feel at home in this book. I had no problem with the probability and statistics in there as I use those in my day to day work. The calculus was wayyyyy in my distant past and I had to gloss over.

Many of the concepts about how CO2 is absorbed by lime, how heat is created and propagated in scrubbers, how cold water impacts scrubbers, how lime size and particle distribution affects 'work of breathing', gas density and density limits, and related topics we discuss here are included. But that coverage is not even. The section on CO2 absorption was the longest. Cold water and scrubber insulation also got considerable pages. Particle size and distribution was discussed but not quite as extensively. Work of breathing and gas density got covered but not nearly so exhaustively. It's a bit of a history of the author's work at NEDU and he recently retired so it feels like the topics that got the most attention over his career got the most attention in the book.

Was worth reading but probably not "required" reading for CCR divers.

Thanks for the detailed review

 

[rjack321]

Didn't CE standards in some cases address that? IE: some scrubbers have a "real" potential life of 5-6 hours yet due to CE, they're restricted far below that.

The standard CE conditions have a high O2 consumption (1.6 lpm) and cold water (4C) and highish density (air at 40m). The test goes until breakthru at that workload and depth.

So if you don't do a hard working dive at a constant 40m depth in a Swedish mine you can go much longer. How much longer is subject to lots of conjecture as the CE test conditions don't actually represent what recreation divers do. Variance around the mean in theory declines with warmer water temps. But there is still a variance, which is as unknown as the mean scrubber duration for a 40m dive at 8C with a 0.8 lpm O2 consumption. Those kind of realistic dive parameters isn't machine tested by CE or anyone else.

Basically CE created a marvelous conservative standard to compare one scrubber to another - but its next to useless for comparing to an actual dive.

 

[mr_v]

If you understand Matlab or work in Wolfram Mathmatica, you will feel at home in this book. I had no problem with the probability and statistics in there as I use those in my day to day work. The calculus was wayyyyy in my distant past and I had to gloss over.

Ditto. Forced me to review calculus and fluid mechanics. I can't believe how much I forgot over the years.

 

[rjack321]

Ditto. Forced me to review calculus and fluid mechanics. I can't believe how much I forgot over the years.

My knowledge of fluid mechanics is perhaps one grade level up from 6yo John Clarke's "one straw = milkshake difficult"