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Eaton - EMAX -- rotary screw compressor 10HP

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Titanium
Joined
May 28, 2005
Location
AZ
I may be needing to buy a new (additional) compressor to accommodate higher air consumption, and I'm looking for a 10HP rotary screw unit (I think). The 5HP Quincy recip unit just can't keep up with current needs.

Does anyone have current experience with current Eaton or EMAX rotary screw units? I've seen some discussion about these brands in the past here, mostly with respect to country of origin, and it looks to me like both of these brands come from the same factory location in Englewood Ohio. I don't know if some of the components are foreign-sourced, or much else, but I have had the impression that Eaton is historically a "decent" brand. Any input of these or other suggestions welcome.
 
I don't have direct experience with screw compressors but, have been considering them as well. From my research: you may discover you might not actually need more HP. Focus on the CFM rating at the pressure you need. Screw compressors are not supposed to cycle. They are designed to run as continuously as possible. So a 10 HP might very well end up being too big where a 5 HP might be all you need.
 
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One thing I would say to mention as an option,
I bought a screw, 3 years ago, Now they have option to control it from your phone via network.
I sometimes leave for the night or the weekend with something running for long hours,
I can set the mill to shut down after M30.
But the compressor is still on, some would say that's fine because no air draw,
but if you blow an air line your compressor could run non stop, and possibly catch fire (recip, seen it happen, burned friends machine shop down)
So having the option to turn on and off from phone is something I would buy next time.

And in my opinion all compressors are junk or at least similar at this point, pick one, and make some money.

between $4-10k depending, I would be more worried about having a single compressor going out and no backup then having a certain name brand.

I have a cheap Atlas Copco 5HP I paid like $6-7k for, I am going to add another one with no tank as a back up, and increase if needed CFM, as mentioned, don't go too big or it will cycle a lot.
but I want a redundancy compressor, at a loss of over $2,000 a day, I don't want a compressor to be down, it would pay for itself in 3 days relative to down time.

And a refrige air drier is a must, if you don't have one, add it to the cost.

2cents :cheers:
 
Every time anyone mentions Screw Compressors on the internet, someone chimes in and says

Screw compressors are not supposed to cycle. They are designed to run as continuously

I wish someone would explain in detail just exactly why that's a common opinion, and include all the intricate technical details and actual manufacturer data that proves it's a true theory.
 
Every time anyone mentions Screw Compressors on the internet, someone chimes in and says

Screw compressors are not supposed to cycle. They are designed to run as continuously

I wish someone would explain in detail just exactly why that's a common opinion, and include all the intricate technical details and actual manufacturer data that proves it's a true theory.
I don't say that, sure minimize cycling, but a screw compressor gets so frickin hot, I don't want mine running continuous just because it says continuous duty :D
 
I wish someone would explain in detail just exactly why that's a common opinion, and include all the intricate technical details and actual manufacturer data that proves it's a true theory.
Told to me directly by the guys in the Kaeser compressor booth, over the years, at various trade shows.
 
Eaton was known for claiming made in USA, when that was only the tank. They subsequently updated it to "assembled" in USA after catching flak. 10(?) years ago I bought an EMAX piston compressor with great cfm and low RPM ratings. When it showed up, I realized the pump itself was straight from India and motor is WEG.

I had to machine one cast part that aligned poorly and blew a gasket. And the blow off valves look like they were made with a drill press and pliers. Replaced them after one failed. Both repairs were easy, and it works fine...but I wasn't impressed with the USA claim. I honestly would not expect this compressor to last long if it ran full shifts daily. Not bashing them; just my observations. New advertisements from them show a better fit and finish on the pumps, so maybe they are improved.
 
Told to me directly by the guys in the Kaeser compressor booth, over the years, at various trade shows.
Actually every screw compressor vendor states that their screw compressors are 100% duty cycle,
and anyone that has one you can hear that it doesn't like starting and stopping,
the system runs in a oil bath and has a cooler, So they really are design for 100% duty cycle as they mention.
I know people think this sounds strange, but some of these systems are sold without tanks also, so its direct CFM's, no storage.
 
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I bought a 10hp EMAX screw compressor almost exactly 4 years ago. Pretty sure it was the biggest single phase unit you could buy at the time. I ran it for about a year before moving out. The shop we cohabitated with continues to use it every day.

It was/is very okay. It's MUCH louder than I anticipated. Probably louder than the piston compressor it replaced. The variable drive seemed to work well, and the PLC was pretty straightforward. I think the power bill dropped slightly vs the piston compressor. The belt tensioning setup was an absolute joke, and it needed constant tightening, or else it would eat up a pair of drive belts in a month. Also the access for filter and oil changes was not great. It hasn't had any major issues though, and I was so happy the first time I sandblasted something and didn't have to deal with pressure drop. :D

We have a 35hp rogers compressor now, which is obviously a MUCH better compressor, but definitely overkill unless all of the machines are using airblast simultaneously.

One thing everyone will tell you - get more air storage. It's the best upgrade you can get, and it's relatively cheap. If (god forbid) our Rogers compressor ever dies, I will probably replace it with a smaller screw and another 1000 gallon vertical tank.
 
Every time anyone mentions Screw Compressors on the internet, someone chimes in and says

Screw compressors are not supposed to cycle. They are designed to run as continuously

I wish someone would explain in detail just exactly why that's a common opinion, and include all the intricate technical details and actual manufacturer data that proves it's a true theory.

My big screw compressor turns off automatically when it stays unloaded for too long. The timers are set so that the most it could ever turn on/off is 6 times in an hour. I was told by the tech that it is set that way because start ups are hard on everything due to less ideal lubrication. Makes sense if you think of it like starting up an internal combustion engine.

The other factor is heat helps get water out of the system. If we've only got one machine turned on in the shop, the compressor only loads up for about 30 seconds at a time, and a LOT more water gets caught at the dryer.
 
Told to me directly by the guys in the Kaeser compressor booth, over the years, at various trade shows.
Um...You do realize Kaeser (and the other brands) sell parts, tech labor time, and new compressors? The longer they run the more money they make. Sales and marketing.
I'm no fan of Kaeser so that doesn't help. Over priced, over hyped.

I know it can, but I dont let my compressor run all day long, if your going to, you better have it in its own room, with through ventilation because they create a LOT OF HEAT!
I can't afford to run any compressor continuous. So I don't. The diesel sorta has to run continous when I'm using it tho.

My big screw compressor turns off automatically when it stays unloaded for too long. The timers are set so that the most it could ever turn on/off is 6 times in an hour. I was told by the tech that it is set that way because start ups are hard on everything due to less ideal lubrication. Makes sense if you think of it like starting up an internal combustion engine.

The other factor is heat helps get water out of the system.

There was a study. And they found out in a pressure differential lubrication system, lube doesn't flow at zero PSI system pressure. So metal bits might contact each other. That would be cold startup. After initial warm up / start up, things get better. So, yes maybe similar to an engine.
All of my screw compressors go thru cold startup, no way to avoid it. As long as they run warm enough to boil off water, and maybe run unloaded a bit to cool down before stopping, I don't think there's going to be any problem with start/stop operation.
 

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  • Investigation of Start Up Process in Oil Flooded Twin Screw Compr.pdf
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My experience of big screws (1000hp +) is they fill with oil when stopped ,and I d think the effect of solid oil flow on the separator elements might be more of a an issue .........place I was ,the new owners were agents for an Indian compressor ,and replaced all the motley crew of dressers ,sullairs ,atlas , with new Indian compressors that were appalling crap ,and caused the closure of the place ........the new owners were more interested in the real estate ,and the place is now a steel frame fabrication shop,which was alwasy their primary interest.............Of interest to some ,the new owners were farmers who built industrial sheds,and imported lots of Chineese and Indian crap ....like the ChinaKat dozers ....one of their salesmen was shot dead over a ChinaKat dozer that was absolute.crap.
 
Incidentally ,the only problem I ever saw with screws was heat .......and where I was that was partly down to poor layout .......a couple of the screws would shut down with over heat ...easily cured by eliminating the shutdown circuit ..........There is some obscure law that where air is breathed ,oil flooded units must not exceed 110C delivery temp.....The theory is that over 110C ,carbon monoxide content of the air increases ...or summat .............I never told anyone ,needless to say .
 
Hello, this is Jerry, we are screw compressor manufacturer since 1996, we have 10hp screw compressor meet your requirement, let's talk.
 








 
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