Fridge compressors are a lort quieter than regular compressors and quite easy to come by
i was wondering if i could use one for an air compressor because my compressor is so noisy it is really annoying and i can not use it late at night.
The freon stuff inside is a gas at one point, im not sure if its a liquid or a gas when it passes through the compressor. if its a gas it ought to work, the other question is how much pressure it can produce, it needs to do 80-100 PSI
i was wondering if i could use one for an air compressor because my compressor is so noisy it is really annoying and i can not use it late at night.
The freon stuff inside is a gas at one point, im not sure if its a liquid or a gas when it passes through the compressor. if its a gas it ought to work, the other question is how much pressure it can produce, it needs to do 80-100 PSI
thats a good thing, my compressor and tank are separate units. so all i probably need is a pressure controlled switch to turn it on when the pressure is below a certain level,
the tank has a gauge on it as well.
I have a friend who is a scrapper, ill ask him to look out for a nice big one!
most of the things i use air for do not use a great deal of CFM.
if i want to paint or something that needs a lot of air ill just use the noisy one.
the tank has a gauge on it as well.
I have a friend who is a scrapper, ill ask him to look out for a nice big one!
most of the things i use air for do not use a great deal of CFM.
if i want to paint or something that needs a lot of air ill just use the noisy one.
Not sure about air considioning but for domestic refrigeration the oil should not circulate around. After laying a fridge down for transport it should always be left upright for an hour before applying power. If any oil does get into the pump's intake it will "hydraulic" the compressor and burn the motor out.
The pump inside the pumpkin does sit in a bath of oil, if too much oil is lost the pump will quickly fail.
CFM rating of a fridge compressor is very, very small. (CFM = cubic feet mer minute) You need about 12 CFM for a pneumatic drill and about 17 for spraypainting. The power required to run both types of compressors should give a rough indication of the capacity. About 150-200 watts versus 1500-2400 watts.
Check the sticker on the refrigeration system before "liberating" the compressor. R200 is flammable. R12 and R22 are chloroflurocarbons and should not be released to atmosphere.
Automotive air conditioning compressors with some modifications make excellent air compressors.
The pump inside the pumpkin does sit in a bath of oil, if too much oil is lost the pump will quickly fail.
CFM rating of a fridge compressor is very, very small. (CFM = cubic feet mer minute) You need about 12 CFM for a pneumatic drill and about 17 for spraypainting. The power required to run both types of compressors should give a rough indication of the capacity. About 150-200 watts versus 1500-2400 watts.
Check the sticker on the refrigeration system before "liberating" the compressor. R200 is flammable. R12 and R22 are chloroflurocarbons and should not be released to atmosphere.
Automotive air conditioning compressors with some modifications make excellent air compressors.
Hi,
A friend built one from a fridge compressor and a propane tank.
The normal pressure in a propane tank is about 80psi so 100psi is an overload.
But if you fill the propane tank with water and ensure all the air is removed then couple up a test gauge and water pump (something like a grease gun action would do). You can do a relatively safe HYDRAULIC TEST. Take this to 50% more than your expected MAXIMUM working pressure. If you want 100psi as a normal working pressure then your regulator controlling the on/off of the compressor will be set to 105 to 110psi.
There will be a safety relief valve set point, another 5 to 10psi above this. Your maximum working pressure is the +tolerance on the safety relief. You have a total of 105 + [5 to 10] + [5 to 10] +% = about 120 to 130psi = Hydraulic test pressure of about 180psi.
Repeat this safety test at about yearly intervals and if the tank ever gets a knock.
.DO NOT air pressure test the tank.
You could kill yourself and anyone in the vicinity.
A friend built one from a fridge compressor and a propane tank.
The normal pressure in a propane tank is about 80psi so 100psi is an overload.
But if you fill the propane tank with water and ensure all the air is removed then couple up a test gauge and water pump (something like a grease gun action would do). You can do a relatively safe HYDRAULIC TEST. Take this to 50% more than your expected MAXIMUM working pressure. If you want 100psi as a normal working pressure then your regulator controlling the on/off of the compressor will be set to 105 to 110psi.
There will be a safety relief valve set point, another 5 to 10psi above this. Your maximum working pressure is the +tolerance on the safety relief. You have a total of 105 + [5 to 10] + [5 to 10] +% = about 120 to 130psi = Hydraulic test pressure of about 180psi.
Repeat this safety test at about yearly intervals and if the tank ever gets a knock.
.DO NOT air pressure test the tank.
You could kill yourself and anyone in the vicinity.
A cautionary tale:
A friend was using a home modified compressor (commercial ~50gallon tank) that had worked well for quite some time. Air when compressed liberates water and even when drained regularly via the valve at the bottom of the tank there is risk of corrosion. Anyway, my friend rested his hand on the tank and bent over to check the pressure (to shut it off before the limit switch did - probably because of noise
) and the thing exploded. It burst apart at the (corroded) welds, blew him backwards and crushed all the bones in his wrist and broke a few metacarpals, permanently limiting his functionality. I can only imagine the pain, some of which he still experiences, I am sure.
A friend was using a home modified compressor (commercial ~50gallon tank) that had worked well for quite some time. Air when compressed liberates water and even when drained regularly via the valve at the bottom of the tank there is risk of corrosion. Anyway, my friend rested his hand on the tank and bent over to check the pressure (to shut it off before the limit switch did - probably because of noise
) and the thing exploded. It burst apart at the (corroded) welds, blew him backwards and crushed all the bones in his wrist and broke a few metacarpals, permanently limiting his functionality. I can only imagine the pain, some of which he still experiences, I am sure.
Its not going to kill anyone any more than the other compressor would. its the same tank! i havent heard about too many people or pets being injured by fridge compressor.
and even though its quite new and doesnt have rust inside, im still very careful. and only check the drain valve when the pressure is around 5 psi.
and otherwise its behind a door.
the enclosure idea for the compressor, i tried it, even with enclosure and rubber engine mounts it is still too noisy. because i have to make vents for the air to get in and the heat to escape.
and even though its quite new and doesnt have rust inside, im still very careful. and only check the drain valve when the pressure is around 5 psi.
and otherwise its behind a door.
the enclosure idea for the compressor, i tried it, even with enclosure and rubber engine mounts it is still too noisy. because i have to make vents for the air to get in and the heat to escape.
I have seen photographs of the damage from a 50 litre tank failure in a garage with plaster walls. Pieces of the tank punched holes through the steel roller-door. The walls were shredded like wet paper. The door will not protect you unless it is of solid construction and closed with a very strong latch. Imagine a balloon popping, now imagine the pieces of rubber are steel travelling at ten times the speed.
The fridge compressor could be teed into the system after the check-valve and the pressure switch fitted with a socket, you could unplug the big motor and plug in the fridge compressor into the pressure switch.
The fridge compressor should up okay against pressure unlike a conventional compressor, though a check valve would be a good idea.
The fridge compressor could be teed into the system after the check-valve and the pressure switch fitted with a socket, you could unplug the big motor and plug in the fridge compressor into the pressure switch.
The fridge compressor should up okay against pressure unlike a conventional compressor, though a check valve would be a good idea.
why would a tank shatter in to a million pieces all flying everywhere. once the first hole rusted through the pressure would rapidly drop maybe shooting a bit of rusty metal in the direction of the hole.
There would be nothing to "explode" with a rapidly decreasing PSI rather the a normal explosion of gas where the PSI increases exponentially
when you get some idiots welding a propane tank that still has some propane in it..well thats different!
There would be nothing to "explode" with a rapidly decreasing PSI rather the a normal explosion of gas where the PSI increases exponentially
when you get some idiots welding a propane tank that still has some propane in it..well thats different!
neutron7 said:
This is also the only version of this story I have seen IRL. The tank goes leaky and you ditch it. The other doom day stories are about as rare as non existing. The chance to win 20 millions in the lottery are much bigger. It happens at least once a week to somebody in the world
Magura
Ask a Metallurgist. Something to do with poor alloys and corrosion along paths in the metal. I expect it was a very old and very cheap tank. Constant working of the tank from pressure cycles weakens these corrosion flaws in the metal.
If a seam burst along one of the corrosion lines the shock could fracture the rest.
I've seen a bolt that snapped because the incorrect anti-seize compound was used. Metals in the anti-seize ate their way though the bolt from electrolytic corrosion. You could see the path eaten through the bolt in the fractured face.
Given time strange things can happen with metal. I wouldn't use a compressor tank more than 10 years old.
Back on topic: the fridge compressor should be fine if connected correctly. It will be slow.
If you have the correct accessories SCUBA bottles are a great silent source of compressed air. They are pressurised to 230 atmospheres. that's a LOT of air. If you live near a popular dive spot refills are cheap from your local dive shop.
If a seam burst along one of the corrosion lines the shock could fracture the rest.
I've seen a bolt that snapped because the incorrect anti-seize compound was used. Metals in the anti-seize ate their way though the bolt from electrolytic corrosion. You could see the path eaten through the bolt in the fractured face.
Given time strange things can happen with metal. I wouldn't use a compressor tank more than 10 years old.
Back on topic: the fridge compressor should be fine if connected correctly. It will be slow.
If you have the correct accessories SCUBA bottles are a great silent source of compressed air. They are pressurised to 230 atmospheres. that's a LOT of air. If you live near a popular dive spot refills are cheap from your local dive shop.
I would also advise a few scuba tanks in series. You will most likely never burst them...and they are usually rated to a max allowable working pressure of 2000 psi. You will likely burn up the compressor before ever bursting a Scuba tank
Cyclic pressuring/depressuring vessels induces fatigue failure, so using an over rated Scuba Tank as the pressure vessel is your best bet for cyclic service.
As previously advised, never pnuematic test a pressure vessel. You pack a monstrous amount of potential energy. I saw the results of a pneumatic test on a heat exchanger when the channel flange blew off. Crushed an inspector in line of fire. Didn't take much pressure either. They were trying to save time and deemed it too cold for a hydrotest...big mistake.
Water is a non compressible fluid, so when it finds a leak, it won't blow apart like a gas.
Cyclic pressuring/depressuring vessels induces fatigue failure, so using an over rated Scuba Tank as the pressure vessel is your best bet for cyclic service.
As previously advised, never pnuematic test a pressure vessel. You pack a monstrous amount of potential energy. I saw the results of a pneumatic test on a heat exchanger when the channel flange blew off. Crushed an inspector in line of fire. Didn't take much pressure either. They were trying to save time and deemed it too cold for a hydrotest...big mistake.
Water is a non compressible fluid, so when it finds a leak, it won't blow apart like a gas.
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