Most compact compressor for 300 cfm at 50 psi

[diyfarmer]

I want to build a manure application bar with an integrated compressor for cleaning out the drag hoses by pushing a foam plug from the field back to the storage pit. What's a simple, compact and inexpensive way to generate 300 cfm at 50 psi powered by a 1000 rpm tractor pto shaft?

One thought was a vane compressor but the ones used on sewage tankers and such are often only rated to 20 psi output. Higher pressure ones often require external lubrication and cooling systems which is no longer simple or compact.

Another thought was an old engine with custom built heads but I'm struggling to find a good source for suction and exhaust valves.

Thanks in advance for your ideas!

 

[drawoh]

diyfarmer,

Is 300cfm in, or out?

--
JHG

 

[kjoiner]

Would a Roots style or screw style compressor work?

Kyle

 

[diyfarmer]

300 cfm in.

Screw compressors are definitely the most common for that kind of capacity, but they require oil separators and coolers which is no longer simple or compact. The compressor that we currently use is a large sullair screw compressor that I converted to pto drive. It was formerly powered by a 150 hp electric motor. I am running it about half speed as that's all the tractor can handle.

 

[kjoiner]

Hello,

Taking a quick look at this site, it appears you'll need at least 35-40 hp not including other variables.

https://www.engineeringtoolbox.com/horsepower-compressed-air-d_1363.html

Kyle

 

[MintJulep]

300 cfm for how long?

Big reservoir and a small compressor?

 

[diyfarmer]

The tractor we use on the applicator bar is about 95 pto hp.

We also use this compressor for cleaning off equipment so it can run for an hour or more. A tank won't cut it.

 

[Compositepro]

If you are pushing a cleaning plug though a line (a process called pigging, btw) you should be using water, not air. Compressing air stores a great deal of energy that is not being used to push the the pig. If you simply want to clear the line of liquid you do not need 50psi. Air pressure released after the pig clears the line is a major safety hazard, and there are OSHA regulations prohibiting such practices. Although you probably do not fall under OSHA jurisdiction, you need to be aware of potential hazards.

 

[3DDave]

Compositepro - it's a farm, not a petroleum company. I suppose there could be a pig involved.

 

[miningman]

And pigs have been known to squeal excessively if subjected to pressure in excess of 14.7 psi.

 

[Compositepro]

I know, and I live on a farm. Farming is one of the most dangerous professions due to many farmers not being aware of potential hazards.

https://www.youtube.com/watch?v=UAr5Yvzdx6o

https://www.youtube.com/watch?v=HO9l6WTspac

https://www.youtube.com/watch?v=Iaud0QI3i3M

 

[3DDave]

Composite - sorry - I missed the "hoses" after "manure spreader." I do agree that farming is one of the most dangerous professions; too many run afoul of PTOs when clearing jams or belt-driven equipment when cutouts and protective panels are removed to deal with other failures.

 

[diyfarmer]

Yes, we call it a pig, but I figured "foam plug" would make more sense to most people!
The hoses have to be flat and therefore empty to roll them up, pushing the pig with water is pointless.
Too little air is hopeless as it takes forever to clean out the hoses and the pig will often get stuck at a kink if the air can get by it. As the pig nears the end, the pressure drops as there is less and less liquid to push out. The launcher is 20' away from the tractor and pointed the opposite way, hundreds of feet of open field all around. All three of those videos had an unrestrained hose which is not the case for us. Also, the worker who unfortunately was killed, was not killed by the hose.

Anyway, back to the original question: I need a simple compact compressor for 300 cfm and 50 psi.

 

[pmover]

an internet search for "tractor pto driven air compressor" provided this result:
-

https://www.vanair.com/images/new-product-brochures/underdeck/Underdeck_STANDARD_0718.pdf

not quite the required 300-cfm, but the largest delivers 200-cfm at 100-150 psig. call them and see what can be done to deliver the 300-cfm at 50-psig.

 

[Compositepro]

You could make a pair of powered nip rollers from some car tires and squeeze the contents out of the hose as you roll it up.

 

[btrueblood]

Or drive down the length of the hose with the tractor...

 

[Tmoose]

Squishing some hose materials completely flat might do bad things to the edges.

https://www.new-line.com/information/causes-of-hose-failure