Ive already got a belt drive 12.5CFM compressor, so its not to replace that, but to do a job that the main compressor doesnt do that well.
I need to pressurise air up to around 30psi, with reasonable volume to run a siphon feed waste oil burner jet. On the main compressor it will run at about 50% duty cycle so it was turning on and off and on and off which isn't good for it. I was thinking a car air con compressor might be a suitable option and power it by a 1/2 horsepower electric motor which Ive got a few of lying around.
Any pointers on this project? I will get an old gas bottle as a damper tank, its not going to be high pressure so Im sure the gas bottle will be suitable for that.
Im hoping to put a pressure switch in to active the clutch in the air con compressor and regulate it that way. they turn on and off all day in a car so it should be fine in this too. Something I dont know about is lubrication of the pump, how much is done from the internals of the pump, and how much from the air con gas?
m16d,
Dec 21, 2:41am
An old friend of mine who is a retired plumber,uses a sealed unit fridge compressor to pump air 150 feet underground to bring up thermal hot water. It lasted quita a while,but when it seized up I gave him another one.
tweake,
Dec 21, 3:17am
fairly commonly done with 4wd's. the problem is generally how to lube it. "endless air" generally uses the piston style aircon pumps and they plug some ports and fill them with grease to lube it. but the rotary style would work ok for this application. use an compressed air oiler to supply constant amount of oil into it. as its only feeding a burner i doubt oil in the air stream would hurt it. pay to make it so the oil can't accumulate in the tank.
elect70,
Dec 21, 3:27am
No no no , they dont have rings & ALL fridge compressors rotary included designed to pump oil with the refrigerant . If its not closed circuit it will run out of oil unless you fit an oil separator & feed back to the sump . . Ive seen many try it . Some of old ones like fridgidare belt drives could be made to work if cut a grove in piston & fitted a ring . But why bother .
mrfxit,
Dec 21, 3:35am
An old 2 stroke engine even better suited. Connect to the plug hole Slap on a pressure regulator to maintain constant psi
Plug on and go. You'd probably spend more than that, plus time stuffing around with other bits of No8 wire.
mrfxit,
Dec 21, 6:38am
Still gets oiled via normal crankshaft splashing. Only thing missing would be the spark.
pdc1,
Dec 21, 6:43am
You said two stroke.
tweake,
Dec 21, 9:26am
use the side intake port two stroke engine. block the exhaust (or use it as another intake). use spark plug hole as outlet and fit inline one way valve. poor efficiency as has a ton of dead space.
mrfxit,
Dec 21, 9:32am
Some 2 strokes have a sump. Could also use a 4 stroke mower engine.
grangies,
Dec 21, 9:49am
Who want to have to listen to a bloody lawnmower, or weed-eater engine, run a damn heater? LOL. It would drive me loopy.
kingfisher21,
Dec 21, 10:43am
No, the work and work extremely well, I ran one in my Nissan Safari to pump up tyres etc, used a small inline oiler on the intake side. It never missed a beat in over 10 years and it got hammered.
sr2,
Dec 21, 11:48am
Correct me if I'm wrong but I've never seen a 2 stroke with a sump, do you have an example?
mrfxit,
Dec 21, 7:11pm
Probably right as I can't place a confirmed example right now but didn't the old commer trucks run something like that
One combo was VW flat 4 used 2 pots as motor & 2 as compressor Blanked off 1 pot each side & fitted air cleaner to intake s .
elect70,
Dec 22, 1:42am
Must have got lot of oil in the tyres , Been fridgee for 30 years & i have seen all sorts of things tried with fridge compressors
joanie32,
Dec 22, 5:49am
Side channel blowers are made for low pressure, hi flow applications, no piston, more of a glorified fan ( very simply put). There's some new ones listed on here, but if you keep your eye out you will stumble across plenty of second hand units that you could get for sod all.
joanie32,
Dec 22, 5:50am
every compressor company has an awesome scrap metal bin. - that is why
joanie32,
Dec 22, 5:55am
You gear down a compressor to get more pressure. More pressure = less flow. That's the opposite of what op wants.
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