scrubber dimensions

OceanOpportunity · 12th May 2007, 14:48

Hello all,

looking for info from those who have experiemnted with various axial scrubber dimensions. What is the narrowest diameter that has proven reasonable to breathe through when packed with absorbant? I realize that most folks use roughly a 6-inch diameter scrubber at about 10-inches high, and generally speaking stick with this 1: 1.75 bed dimension ratio. Has anyone gone down to 4" diameter, less? feeback appreciated

Mike

**Dave Sutton** · 12th May 2007, 16:55

US Navy did with the scrubbers on the Mark-VI (02 "Emerson" rig) and the Mark-XI (SCC Deep Rig, designed for Sealab III). Have one of each of the rigs here, and a spare scrubber. Seem to work fine. They are simple axial scrubbers, about 4 inch diameter by about 16 inches long. Photos if desired.

Mike, I'll be aboard EXPLORER Sunday night. Come down to Narragansett for chow. Cell (908) 752-1853.

Dave

OceanOpportunity · 12th May 2007, 17:01

Thanks for the info Dave. Picutres would be much appreciated.

Thanks also for the invite...will be tied up with Mother's Day events this Sunday, but I am very interested in connecting. Let me know when you are generally around and I will make it a point to come down.

Mike

Quote: (Originally Posted by Dave Sutton)

US Navy did with the scrubbers on the Mark-VI (02 "Emerson" rig) and the Mark-XI (SCC Deep Rig, designed for Sealab III). Have one of each of the rigs here, and a spare scrubber. Seem to work fine. They are simple axial scrubbers, about 4 inch diameter by about 16 inches long. Photos if desired.

Mike, I'll be aboard EXPLORER Sunday night. Come down to Narragansett for chow. Cell (908) 752-1853.

Dave

ChristianM · 14th May 2007, 08:08

Hi Mike,

take a look here:
http://www.rebreatherworld.com/close...ebreather.html

I don't know the size of the scrubber. But I guess he will tell you if you ask.

Cheers!
Christian

jmhardingjr · 14th May 2007, 16:49

Hi Mike,

I used a scrubber made of 4" pvc on a homebuild a while back. It was a pure O2 rig, so I can't comment on how it would work if used for mixed gas. Essentially, it was a direct fill axial scrubber canister that used the entire 4" cross section with a 10-12" bed length (it was adjustable) . Like I said, it was a pure O2 rig, so it didn't seem to matter that the diameter to bed length ratio got blown out of the water. It seems like the Emerson O2 rig that Dave described pushed out the diam to length ratio as well, just by quite a bit more than mine did.

Another thing about my O2 rig was that the CL volumes (2 x 4 L) were a bit high and the total loop volume was also high due to some rigid pipe work, headspace in the scubber caps, and long hoses (Jeez, it was so ugly/clunky it was beautiful). I think this helped WOB. I wouldn't allow so much extra volume in a design now, so the 4" diameter may not be seviceable.

Don't know if this applies or helps.

Cheers,

Jay

Crazyduck · 14th May 2007, 17:11

This was kindly released by Gene Hobbs-
He has a scratch sheet from the Navy on formulas from the Navy on Axial scrubbers.
The paper took into account some nice variables.
http://www.rebreatherworld.com/scrub...-revision.html

Depending on the depth-
Tom did a rebreather that was 4” drain pipe but that was a pendulum unit.
The frog had a way small scrubber.
There was the long thread on the ‘micro scrubber’ with some interesting insights.

Another option-
I have been thinking of the oval type axial scrubbers.
It would be interesting to see how the oval changes the gas flow through the scrubber bed. I only say this because the Diameter of your axial scrubber affects your length.

Regards, Andrew

OceanOpportunity · 14th May 2007, 17:50

Hey Jay,

this is helpful. I'm finding that with regard to scrubber efficiency, allowing sufficient dwell time is the most critical element, and is relatively easily achieved when the volume of inhale lung + intergranular space = avg tidal volume. This way, all gas inhaled ihas reacted as much as it is going to (>.5 sec dwell or more). My interest in the smaller diameter scrubbers is for configuration purposes. Work of breathing may indeed increase, but using a split/dual scrubber of small diameter makes it easy to pack into some small places.

will keep you guys abreast as this prototype comes together

hope all is well
Mike

Quote: (Originally Posted by jmhardingjr)

Hi Mike,

I used a scrubber made of 4" pvc on a homebuild a while back. It was a pure O2 rig, so I can't comment on how it would work if used for mixed gas. Essentially, it was a direct fill axial scrubber canister that used the entire 4" cross section with a 10-12" bed length (it was adjustable) . Like I said, it was a pure O2 rig, so it didn't seem to matter that the diameter to bed length ratio got blown out of the water. It seems like the Emerson O2 rig that Dave described pushed out the diam to length ratio as well, just by quite a bit more than mine did.

Another thing about my O2 rig was that the CL volumes (2 x 4 L) were a bit high and the total loop volume was also high due to some rigid pipe work, headspace in the scubber caps, and long hoses (Jeez, it was so ugly/clunky it was beautiful). I think this helped WOB. I wouldn't allow so much extra volume in a design now, so the 4" diameter may not be seviceable.

Don't know if this applies or helps.

Cheers,

Jay

jmhardingjr · 14th May 2007, 18:09

Mike,

Dual scrubber takes me down a whole different train of thought. We should go grab a beer sometime. I've been kicking around a couple of dual scrubber ideas for a while now. I agree with you on the point that it creates a lot more configuration flexibility. I think that it also can introduce a level of redundancy in case of flooding.

I look forward to seeing more about this proto that you are working on as it develops.

Cheers,

Jay

OceanOpportunity · 15th May 2007, 00:10

would love to get together on this..actually,I'm going to try to connect with Dave S this weekend..perhaps we can all meet up

Quote: (Originally Posted by jmhardingjr)

Mike,

Dual scrubber takes me down a whole different train of thought. We should go grab a beer sometime. I've been kicking around a couple of dual scrubber ideas for a while now. I agree with you on the point that it creates a lot more configuration flexibility. I think that it also can introduce a level of redundancy in case of flooding.

I look forward to seeing more about this proto that you are working on as it develops.

Cheers,

Jay

**Dave Sutton** · 15th May 2007, 00:41

Quote: (Originally Posted by OceanOpportunity)

would love to get together on this..actually,I'm going to try to connect with Dave S this weekend..perhaps we can all meet up

I'll be up Thurs/Fri and again Monday. Flying calls me this weekend....

With Jay, you, and a few other guys we have quite a little Rebreather builders club in RI. Let's make a social "back-o-the-boat" night ASAP.

Dave

12th May 2007, 14:48	#1 (permalink)
OceanOpportunity for a world of water Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Dolphin Home Build Join Date: Nov 2006 Location: Providence, RI USA Posts: 596	scrubber dimensions Hello all, looking for info from those who have experiemnted with various axial scrubber dimensions. What is the narrowest diameter that has proven reasonable to breathe through when packed with absorbant? I realize that most folks use roughly a 6-inch diameter scrubber at about 10-inches high, and generally speaking stick with this 1: 1.75 bed dimension ratio. Has anyone gone down to 4" diameter, less? feeback appreciated Mike __________________ Michael Lombardi Oceans of Opportunity www.oceanopportunity.com Elected Director, Society for Human Performance in Extreme Environments MN'07, The Explorers Club Project Manager, Diving a Dream
(Online)

12th May 2007, 16:55	#2 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: scrubber dimensions US Navy did with the scrubbers on the Mark-VI (02 "Emerson" rig) and the Mark-XI (SCC Deep Rig, designed for Sealab III). Have one of each of the rigs here, and a spare scrubber. Seem to work fine. They are simple axial scrubbers, about 4 inch diameter by about 16 inches long. Photos if desired. Mike, I'll be aboard EXPLORER Sunday night. Come down to Narragansett for chow. Cell (908) 752-1853. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

12th May 2007, 17:01	#3 (permalink)
OceanOpportunity for a world of water Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Dolphin Home Build Join Date: Nov 2006 Location: Providence, RI USA Posts: 596	Re: scrubber dimensions Thanks for the info Dave. Picutres would be much appreciated. Thanks also for the invite...will be tied up with Mother's Day events this Sunday, but I am very interested in connecting. Let me know when you are generally around and I will make it a point to come down. Mike Quote: (Originally Posted by Dave Sutton) US Navy did with the scrubbers on the Mark-VI (02 "Emerson" rig) and the Mark-XI (SCC Deep Rig, designed for Sealab III). Have one of each of the rigs here, and a spare scrubber. Seem to work fine. They are simple axial scrubbers, about 4 inch diameter by about 16 inches long. Photos if desired. Mike, I'll be aboard EXPLORER Sunday night. Come down to Narragansett for chow. Cell (908) 752-1853. Dave __________________ Michael Lombardi Oceans of Opportunity www.oceanopportunity.com Elected Director, Society for Human Performance in Extreme Environments MN'07, The Explorers Club Project Manager, Diving a Dream
(Online)

14th May 2007, 08:08	#4 (permalink)
ChristianM RBW Member Current Rebreather/s: Dolphin Home Build Other Rebreather/s: Dolphin Home Build Join Date: Sep 2005 Location: Germany Posts: 59	Re: scrubber dimensions Hi Mike, take a look here: http://www.rebreatherworld.com/close...ebreather.html I don't know the size of the scrubber. But I guess he will tell you if you ask. Cheers! Christian
(Offline)

14th May 2007, 16:49	#5 (permalink)
jmhardingjr Son of a Sailor Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Sep 2005 Location: . . . this one particular harbor . . . Posts: 201	Re: scrubber dimensions Hi Mike, I used a scrubber made of 4" pvc on a homebuild a while back. It was a pure O2 rig, so I can't comment on how it would work if used for mixed gas. Essentially, it was a direct fill axial scrubber canister that used the entire 4" cross section with a 10-12" bed length (it was adjustable) . Like I said, it was a pure O2 rig, so it didn't seem to matter that the diameter to bed length ratio got blown out of the water. It seems like the Emerson O2 rig that Dave described pushed out the diam to length ratio as well, just by quite a bit more than mine did. Another thing about my O2 rig was that the CL volumes (2 x 4 L) were a bit high and the total loop volume was also high due to some rigid pipe work, headspace in the scubber caps, and long hoses (Jeez, it was so ugly/clunky it was beautiful). I think this helped WOB. I wouldn't allow so much extra volume in a design now, so the 4" diameter may not be seviceable. Don't know if this applies or helps. Cheers, Jay __________________ ". . . the sea's in my veins, my tradition remains, I'm just glad I don't live in a trailer . . ."
(Offline)

14th May 2007, 17:11	#6 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 720	Re: scrubber dimensions This was kindly released by Gene Hobbs- He has a scratch sheet from the Navy on formulas from the Navy on Axial scrubbers. The paper took into account some nice variables. http://www.rebreatherworld.com/scrub...-revision.html Depending on the depth- Tom did a rebreather that was 4” drain pipe but that was a pendulum unit. The frog had a way small scrubber. There was the long thread on the ‘micro scrubber’ with some interesting insights. Another option- I have been thinking of the oval type axial scrubbers. It would be interesting to see how the oval changes the gas flow through the scrubber bed. I only say this because the Diameter of your axial scrubber affects your length. Regards, Andrew __________________ Howdy Senor- What’s Happening! Rob Davie April 2005- Presently in a state of transition from Open Circuit to Closed Circuit. "You will not be punished for your anger; you will be punished by it." - Buddha.
(Offline)

14th May 2007, 17:50	#7 (permalink)
OceanOpportunity for a world of water Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Dolphin Home Build Join Date: Nov 2006 Location: Providence, RI USA Posts: 596	Re: scrubber dimensions Hey Jay, this is helpful. I'm finding that with regard to scrubber efficiency, allowing sufficient dwell time is the most critical element, and is relatively easily achieved when the volume of inhale lung + intergranular space = avg tidal volume. This way, all gas inhaled ihas reacted as much as it is going to (>.5 sec dwell or more). My interest in the smaller diameter scrubbers is for configuration purposes. Work of breathing may indeed increase, but using a split/dual scrubber of small diameter makes it easy to pack into some small places. will keep you guys abreast as this prototype comes together hope all is well Mike Quote: (Originally Posted by jmhardingjr) Hi Mike, I used a scrubber made of 4" pvc on a homebuild a while back. It was a pure O2 rig, so I can't comment on how it would work if used for mixed gas. Essentially, it was a direct fill axial scrubber canister that used the entire 4" cross section with a 10-12" bed length (it was adjustable) . Like I said, it was a pure O2 rig, so it didn't seem to matter that the diameter to bed length ratio got blown out of the water. It seems like the Emerson O2 rig that Dave described pushed out the diam to length ratio as well, just by quite a bit more than mine did. Another thing about my O2 rig was that the CL volumes (2 x 4 L) were a bit high and the total loop volume was also high due to some rigid pipe work, headspace in the scubber caps, and long hoses (Jeez, it was so ugly/clunky it was beautiful). I think this helped WOB. I wouldn't allow so much extra volume in a design now, so the 4" diameter may not be seviceable. Don't know if this applies or helps. Cheers, Jay __________________ Michael Lombardi Oceans of Opportunity www.oceanopportunity.com Elected Director, Society for Human Performance in Extreme Environments MN'07, The Explorers Club Project Manager, Diving a Dream
(Online)

14th May 2007, 18:09	#8 (permalink)
jmhardingjr Son of a Sailor Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Sep 2005 Location: . . . this one particular harbor . . . Posts: 201	Re: scrubber dimensions Mike, Dual scrubber takes me down a whole different train of thought. We should go grab a beer sometime. I've been kicking around a couple of dual scrubber ideas for a while now. I agree with you on the point that it creates a lot more configuration flexibility. I think that it also can introduce a level of redundancy in case of flooding. I look forward to seeing more about this proto that you are working on as it develops. Cheers, Jay __________________ ". . . the sea's in my veins, my tradition remains, I'm just glad I don't live in a trailer . . ."
(Offline)

15th May 2007, 00:10	#9 (permalink)
OceanOpportunity for a world of water Current Rebreather/s: Other CCR Dolphin Home Build Other Rebreather/s: Not Bought Yet Inspiration Classic Other CCR Dolphin Home Build Join Date: Nov 2006 Location: Providence, RI USA Posts: 596	Re: scrubber dimensions would love to get together on this..actually,I'm going to try to connect with Dave S this weekend..perhaps we can all meet up Quote: (Originally Posted by jmhardingjr) Mike, Dual scrubber takes me down a whole different train of thought. We should go grab a beer sometime. I've been kicking around a couple of dual scrubber ideas for a while now. I agree with you on the point that it creates a lot more configuration flexibility. I think that it also can introduce a level of redundancy in case of flooding. I look forward to seeing more about this proto that you are working on as it develops. Cheers, Jay __________________ Michael Lombardi Oceans of Opportunity www.oceanopportunity.com Elected Director, Society for Human Performance in Extreme Environments MN'07, The Explorers Club Project Manager, Diving a Dream
(Online)

15th May 2007, 00:41	#10 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: scrubber dimensions Quote: (Originally Posted by OceanOpportunity) would love to get together on this..actually,I'm going to try to connect with Dave S this weekend..perhaps we can all meet up I'll be up Thurs/Fri and again Monday. Flying calls me this weekend.... With Jay, you, and a few other guys we have quite a little Rebreather builders club in RI. Let's make a social "back-o-the-boat" night ASAP. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

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