Gas Booster Drive Gas Volume

[OceanEyes]

Thank you BRT. I thought that I scoured all of the threads at RBW, but managed to miss this 8 year old one. Makes me wonder what else I've overlooked.

 

[iain/hsm]

Didn't someone say we would get to the answer by around post 30 LOL Double it.

To be fair Haskel have never published a performance curve for this model.
This was a requirement omission from the scuba distributors as the less you know the better they sell sort of deal

The un-official answer to how much air drive do I need to run a Haskel Sports Mini is two fold:

First when using a scuba HP supply if we take the last post of:
15 scfm at 7 bar (100psi) FAD Free air delivery. When using a scuba cylinder as the drive air source or HP supply line from a bank
The static pressure you set the regulator to is higher (at static/no flow) and the pressure drop you get down to 100psi is required to effect a flow.

However when using a low pressure air compressor to quote like for like with the 15 scfm drive air you have above you need to add about 33% to get from the quoted 15 cfm displacement figures for the compressor as they are always quoted in displacement (not scfm). To convert displacement to get free air delivery FAD add 30-35%

A two stage low pressure compressor will give better performance for a given motor size and deliver more performance with interstage cooling but the expense is now around the same price as a small 3 stage electric 0.5 BHP oxygen compressor.

You also again to this figure need to add in the calculation factors for high ambient air temperatures over 20C and high humidity areas. This increases again the required displacement requirement for the compressor size.

So for a 15 scfm flow of drive air you need a 19 cfm displacement LP compressor and added to that again is the Humidity and ambient air cooling capacity making it even bigger.

Of course no one does this they just hook up whenever meets the budget and fudge factor the performance.

Next we need to calculate out the inlet source oxygen supply pressure and flow pressure decay as the bottle pressure decreases. As again the lack of detailed calcs force you to compromise on what you believe to be performance.

Finally you need the performance flow rates for minimum oxygen pressure or you ditching good oxygen in the bottle when they drain to 1500 psi and then have the run around of multi cylinder decanting with the dregs.

 

[BRT]

Thank you BRT. I thought that I scoured all of the threads at RBW, but managed to miss this 8 year old one. Makes me wonder what else I've overlooked.

Google is your friend.

 

[OceanEyes]

Google is your friend.

So too is appears are those people who have provided input on this thread. I am truly appreciative for all for your advice, insight, and flashes of humor.

 

[BRT]

So too is appears are those people who have provided input on this thread. I am truly appreciative for all for your advice, insight, and flashes of humor.

I know little about gas boosters but I know there is not much air in a tank. And I know that Google has a better search engine than Scubaboard or any of the others. I used Google to find that rebreather reference. I know you don't want a compressor but think you need one. And I think it will need to be a 220 volt compressor of 5hp or more. Could you put one on a shelf so it was out of the way? You need a fairly large compressor but you don't need a very big tank.

 

[TrimixToo]

I'd forgotten about this, but it could be a great solution for you:

For Sale - Russian KN-4 Booster Pump

 

[OceanEyes]

I know you don't want a compressor but think you need one. And I think it will need to be a 220 volt compressor of 5hp or more. Could you put one on a shelf so it was out of the way? You need a fairly large compressor but you don't need a very big tank.

Thank you BRT for the advice regarding a 5HP compressor, but please see my post #25 in this thread regarding late hours, loud noises, treating my neighbors with courtesy, and getting punched in the throat. A large compressor will not suit my domestic situation if I hope to reach my next birthday with the ability to speak, swallow, or breathe, and retain any hope of being invited to a neighborhood cook-out, pool party, pot-luck supper, or other friendly gathering.

 

[OceanEyes]

I'd forgotten about this, but it could be a great solution for you:

For Sale - Russian KN-4 Booster Pump

One again TrimixToo you’ve my thanks for proposing a colorful alternative. I’m less than enthusiastic about purchasing a used booster unless the seller is known to me personally. That Russian booster has been posted for sale for about half a year now, and while the price continues to drop, I’ve yet to see anyone make a serious offer.

I’ve flown on a few fixed wing and rotary wing aircraft of Russian manufacture, and I’m not looking forward to the next time that one of these is my sole means of transport. I’ve got a friend who purchased a hefty Soviet dive watch at what he thought was a bargain price. It flooded on his first dive with it. I’ve spent some time on a Russian ice-breaker. She was a seaworthy vessel, but the marine heads were particularly problematic, rustic, and pungent. I am entirely ignorant of the Russian language and the Cyrillic alphabet. The idea of trying to decipher the OEM’s operations manual, specification sheets, parts index, and repair procedures is a task beyond my practical ability.

 

[TrimixToo]

One again TrimixToo you’ve my thanks for proposing a colorful alternative. I’m less than enthusiastic about purchasing a used booster unless the seller is known to me personally. That Russian booster has been posted for sale for about half a year now, and while the price continues to drop, I’ve yet to see anyone make a serious offer.

I’ve flown on a few fixed wing and rotary wing aircraft of Russian manufacture, and I’m not looking forward to the next time that one of these is my sole means of transport. I’ve got a friend who purchased a hefty Soviet dive watch at what he thought was a bargain price. It flooded on his first dive with it. I’ve spent some time on a Russian ice-breaker. She was a seaworthy vessel, but the marine heads were particularly problematic, rustic, and pungent. I am entirely ignorant of the Russian language and the Cyrillic alphabet. The idea of trying to decipher the OEM’s operations manual, specification sheets, parts index, and repair procedures is a task beyond my practical ability.

Well, you still might consider an electric one. AA tends toward pricey but there are probably other sources of used ones. See the Sierra booster here: Used Haskel Boosters and Haskel Air Amplifiers I'd start by calling Porter at August Industries to see what he's got or would recommend.

AA wants a bit over 4K for a used Sierra booster, about double the cost of the Haskel you were thinking of, but not too far from Haskel+compressor territory.

 

[Wookie]

Well, Hell. Even I have a used Masterline for sale, but theSierra isn't O2 rated out of the box. You have to pt in an O2 kit, which doesn't seem to be available any more....