Astro_Al Posted March 19, 2008 Share Posted March 19, 2008 Right I'd appreciate some clarification on my air supply. I need to supply this to a tool: Gas Inlet Pressure and Flow: 90 psig (6.1 bar) & 550 scfh / 9.2 scfm (260 l/min) My compressor is specced as follows: RECEIVER SIZE LITRES: 150 MOTOR HP: 3.0 (2.2KW) AIR DISPLACEMENT CFM: 13.0 (368 L/MIN) MAXIMUM FREE AIR DELIVERY CFM: 9.1 (258 L/MIN) FREE AIR AIR DELIVERY CFM: 7.8 (221 L/MIN) MAXIMUM PRESSURE PSI; 131 (9 BAR) Now, max pressure is 9 bar, so that's ok. But do I go on 'Max Free Air Delivery' (which is ok (JUST)), or 'Free Air delivery' (which is not ok) for the flow? I'm guessing 'air displacement' is a pretty meaningless figure in real terms? I know what you'er going to say, don't I... Cheers, Al. Quote Link to comment Share on other sites More sharing options...
will_warne Posted March 19, 2008 Share Posted March 19, 2008 Al, what's the tool? My guess is that max free air delivery is when you've got a full tank of air behind you while free air delivery will be delivery from an empty tank. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 19, 2008 Author Share Posted March 19, 2008 Al, what's the tool? Vapour inflator. (New plasma). If I ever actually get my hands on it. Yes, maybe you're right, anyone care to confirm / deny? Al. Quote Link to comment Share on other sites More sharing options...
clbarclay Posted March 19, 2008 Share Posted March 19, 2008 If you are only going to run the tool for short periods then a big resevoir and bigest bore pipe you can get will work. The down side is you will have to keep waiting for pressure to build back up if you are going to do a lot with it. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted March 19, 2008 Author Share Posted March 19, 2008 You mean in general? Or specifically looking at the specs I posted? Thanks, Al. Quote Link to comment Share on other sites More sharing options...
paintman Posted March 19, 2008 Share Posted March 19, 2008 It will struggle. 'Free air delivery' is the relevant figure. As the tool requires more than the compressor can deliver the pressure in the tank will drop & the tool will slow. Fine for short periods but you will then have to wait until the tank builds up again. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted May 28, 2008 Author Share Posted May 28, 2008 Well, thanks for the inputs on this. Sadly the compressor keeps up for a few seconds only before needing to recharge the tank. I had hoped that the plasma would be useable for manual work, but not for more continuous (CNC style) cutting with this compressor, but it looks like its not going to work. I also have a shotblasting jobber to set up which can happily take more air than I can supply. So does anyone have a 3 phase compressor kicking about? Or can recommend a good value for money machine? My single phase one is a SIP one, and I've probably had it out of action with regulator and piping issues for more time than its been switched on, so I'd like something a little better on the quality side. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
disco_al Posted May 28, 2008 Share Posted May 28, 2008 what about converting an old gas cylinder into another reservoir, so that you then have a main tank to feed off whilst the compressor refills the supply tank? Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted May 28, 2008 Author Share Posted May 28, 2008 I think thats just delaying the problem. To just enlarge the reservoir is not addressing the real issue which is that the motor can't supply as much as the tool is using. At the mo a 150 ltr full tank lasts a very short time before dipping below 6 bar and needing a refill. So even doubling that time (with and extra 150 ltr tank) would only delay it by a few seconds. Cheers, Al. Quote Link to comment Share on other sites More sharing options...
pugwash Posted May 28, 2008 Share Posted May 28, 2008 Al PM TJ101 and ask whether he wants to get rid of his old 3 phase compressor. Its quite old but by god it shifts some air. Quote Link to comment Share on other sites More sharing options...
Paul Wightman Posted May 29, 2008 Share Posted May 29, 2008 Al, two comments- I can't believe a plasma needs that volume of air, my Air Liquide 215 15mm cut 3 phase machine has run off a 2 HP single phase compressor with no issues at all. How much air flow can you get through a 1.5mm hole? If you do need a larger compressor then I would suggest you look at a Hydrovane which is the ideal tool to supply high CFM. Quote Link to comment Share on other sites More sharing options...
disco_al Posted May 29, 2008 Share Posted May 29, 2008 would this feed it? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...52BSI%26otn%3D4 :) Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted May 29, 2008 Author Share Posted May 29, 2008 Thanks guys. Paul - the plasma specs are in the first post of this thread (in terms of air demand). It is a bit of a beast (conservatively rated at 1 3/4" severance). I can confirm that it really does use this air, as my compressor can't keep up for long. Thanks I'll check out some used hydrovanes - I heard they are pretty useful. Disco_al - thanks, they're actually in my favourite sellers list, but I hadn't seen that yet... Hmmm... I am SO running out of space though... I did get offered a cheapo 3 phase one by a delivery driver who helped me manhandle yet another unnecessary and stupidly heavy tool into my workshop, but its been sat out in his front garden so I'm a bit reluctant to pursue it. I need one that actually works (for once). Thanks for the pointers, Al. P.S. thanks puggers - I'll send him a msg. Quote Link to comment Share on other sites More sharing options...
wkw90 Posted May 29, 2008 Share Posted May 29, 2008 what about converting an old gas cylinder into another reservoir, so that you then have a main tank to feed off whilst the compressor refills the supply tank? How would you go about doing that ? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted May 30, 2008 Share Posted May 30, 2008 FFS Al the fad is HOW F MUCH ? What the hibber d gibbert have you gone and bought now ? A thermal F lance or a Plasma ? The carbon footprint of it must be equal with F china ? PICS Nige Quote Link to comment Share on other sites More sharing options...
MogLite Posted May 30, 2008 Share Posted May 30, 2008 PICS I'm not sure if Al is around at the moment, nothing moves very fast in his workshop. Do you want me to nip over there tomorrow with my PinHole camera and take some photographic plates Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted May 30, 2008 Share Posted May 30, 2008 Andy You should exercise extreme care The amount of equipement per 'Sq In' is at risk of damaging the space time fabric ..and space could implode at anytime with a resultant black hole (and the odd tig or 2 in it) . Having said that pics would be good nige Quote Link to comment Share on other sites More sharing options...
Redhand Posted May 30, 2008 Share Posted May 30, 2008 How would you go about doing that ? Remove the valve from a gas bottle and replace with a new fitting with an air inlet with pressure relief valve on it. Have a pipe between compressor and gas bottle with a tee peice fitted with an hose connector. hey presto doubled capacity. Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted June 1, 2008 Author Share Posted June 1, 2008 What the hibber d gibbert have you gone and bought now ? Its a Hypertherm Powermax 1650. For its performance its actually very small and light - only 60 kgs or so. I was looking for something 3 phase with an inch capacity or more, and this one happened to come up in good nick used. I got a hell of a good deal on it, just had to manage the shipping from the states from a recalcitrant xenophobic paranoid schizophrenic. My new favourite toy, I just need to apply for a government grant to buy the consumables. Believe it or not, I am actually trying to tidy up and clear out the workshop... Al. Quote Link to comment Share on other sites More sharing options...
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