Rotary Screw Air Compressor: What are they?! Worth the hype?
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- เผยแพร่เมื่อ 11 มิ.ย. 2016
- This video summarizes the basics of what a rotary screw air compressor is, why we bought an Atlas Copco Screw Compressor, some of their drawbacks and things you should consider if you're thinking about buying a rotary screw compressor!
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Links for this video:
Here's a GREAT, quiet air compressor for small shop or dedicated machines: amzn.to/1OkZ9q7
Thanks to Cleaveland Tool for help with the RapidAir! You can buy through them at bit.ly/1UoPLSY
Music copyrighted by John Saunders
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it's good to see people using decent gear, I just started working for a compressor company and we service and repair up to 200kw units. they are huge and produce an incredible amount of air. screw compressors are incredible machines. this one is only a baby. I took out a motor from a 70kw in the workshop and that baby needed an engine hoist!
You want a wet tank system because the air right out of the screws is hot, the refrigerated dryer works better if it doesn't have to take the excess compression heat out before chilling the air to condense the moisture. The reason you want to try to keep the screws running as continuously as possible is because the oil separator and the oil flow thru the screws needs to stabilize for lowest oil bypass. If the air and oil are flowing through the screws at a stable level, the separator will work at its best. On startup or major disturbance of the flow, the screw can starve for oil and the separator can bypass. Hope this makes sense.
Wet tank is not needed in this compressor. The compressor comes with a build in after-cooler that eliminates majority of the moisture.
This machine has a built in aftercool system that will cool the discharge air within 10 degrees Fahrenheit, plus or minus a few, of your ambient temperature. Running through a dryer without a wet tank is a typical set up for most applications. As long as the coolers, filters, valves and thermostat are working properly and atlas copcos recommended preventative maintenance intervals are executed properly.
If the sole reason you're bummed about not having a computer on board the compressor is due to the shutoff timer, you could always install an off delay relay in the control circuit to extend the run time beyond the signal provided by the pressure switch. Couple that with either a solenoid actuated relief valve in the same circuit or even a mechanical pressure relief valve to handle the tank overpressuring issue, and you've accomplished the same thing.
I would recommend putting the recip in series with the screw, so you can run either depending on your needs. That will eliminate the screw cycling on and off. After the warranty period, you can probably get a VFD to control the motor on the screw compressor, which will be more efficient and allow for soft starts or throttling without having to cycle off. Also, an additional external oil separator will get the oil down to 1-2ppm in the service lines.
One other comment and this is based on my 35+ years of building refinery projects that included air systems for plant air and instrument air. For a loop as long as yours, I would recommend using a main header loop at least 2 sizes bigger than your drops to your work stations. This way you have a header system that can accommodate heavy air demand from multiple air stations. If your main header is undersized, you have negated the capability of your compressor (i.e., it cannot push the air into the system fast enough to compensate for the draw down due to pressure drop loss in the piping system).We typically use a 4" header with 2" subheaders to feed about 100 3/4" air supply points in a refinery process unit. This insures constant pressure at all the instrument stations and control valve stations. Think of it this way, if you have 15 drops on your loop and all of them get used at once, you need a reserve in the piping system itself for the compressor to fill up from the tank.You may not have heavy air demand now, but if you plan on future expansion, you might want to consider re-sizing the header loop.Regards;Ron Kluwe
Ran some quick sizing calcs for you and at about 40 CFM of draw, it looks like your current system will go to Zero PSIG at the drop end points with the header it appears you currently have (I am assuming 3/4" tubing throughout). The system is essentially choked at this flow rate as the compressor cannot push enough air into the header, no matter how big the compressor is. If you upsize to a 1.5" header for the main loop, this is only about a 3PSI drop in air pressure at 45 CFM demand and a 12 PSI drop in air pressure at 90 CFM demand. Also, typical practice is to put a large air receiver vessel after the drying system in order to limit surge demand on the compressor. For the volume of pipe in your shop, it looks like a 300 gallon air receiver will give about a 5 minute surge coverage and a 600 gallon air receiver will give about a 10 minute surge coverage. Something to think about to ensure longevity of your air system and flexibility for future expansion. I can fill you in more on this at the BarZ Summer Bash.
+NYC CNC there is a difference between pipe of a certain size and a single choke point. Your long run could benefit greatly from a diameter increase.
Put a 300 or 600 gallon receiver tank in the system and you can run your compressor all day at 20 CFM and maintain 125 PSIG at the outlet points. Even with short term demand (5 or 10 minutes at a time) to 30 CFM you can maintain about 115 PSIG at the outlets. I am very surprised that Atlas Copco would limit the output to a 1/2" outlet size. My bet is that if you look into the guts of the machine, it is the air drying system that is the limiter on flow and that they are using 1/2" tubing for that system. Might want to ask them if a 1" outlet can be installed at the compressor.
I waS thinking the same thing... thats some tiny pipe for such long runs. Especially right off the reciever tank... seeing the video more it seems like a very badly made system
My former shop system had a 15hp piston compressor in a back room and we had 3 80 gallon tanks plumbed into a 3” main line that ran the length of the building and each station dropped off that main. We had two air dryer systems. A main refrigerator dryer, and a secondary for paintwork, powder coating, and so on. We used a lot of air, rarely did it run down it worked well to maintain power tools, etc... sadly the tri piston compressor was ridiculously loud.
Beautiful shop!, first time watching your vids!
I have used and worked around a number of screw comps, 10hp to 65hp, and they are definitely a nice compressor compared to piston comps.
They are designed to use oil to help sealing of the rotors and pass a LOT of it out the discharge, and the oil separator should catch 99% of it, but a external refrigerated dryer with proper filters and traps, will give you superbly clean air!, again, not cheap, but worth it in the long run!.
The one at my old work is an Italian made 10hp unit (ABAC or some company), and the auto-drains did dump a tiny bit of oil outside the shop, but very very little. not enough to show on the sight glass between services, its literally vapor, compared to some piston comps that blurt out oily milky goop every time you drain them.
Best of luck with it!, wish I could have one at home and at work :D
I work at a tobacco facility at this time and Atlas Copco is the name of the game there having at least 20 of their bigger compressors, some even hooked in parrallel to keep up, with all the dehydrators and stuff all around the plant...At this point though there are room heat issues and they will be installing some equally extreme ventilation system in all the compressor rooms before the summer takes a toll on them!
Didn't even know they made such a thing as a screw air compressor! lol learn something new every time I watch your channel John. Thanks and Happy Holidays to you and your team and family!
I like this video a lot. It shows you did your research and I think it shows the progression of learning air compressors. Well done sir.
I always learn so much from the way you explain things John..really appriecate your veiw an all the research you do..thanks
Love your explanations and your insight on this system you just installed. Thank you for sharing this!
Thanks John for the very informative Air Compressor video!
As far as monitoring your machines. installing cameras in your machines might be useful. Either a multicamera analog security system, or a set of IP cameras permanently mounted in your machines. You could just add a secondary monitor in your office with a split view for each machine. Perhaps even remote e-stop buttons in your office so you can stop a machine if you spot a problem with out have to run across the room.
When I came to a new job it was in a warehouse kind of building with high metal ceilings and it was very loud with a lot of echoing. Later on they did noise abatement by hanging cloth in vertical sections in sort of a zig zag pattern and it made a huge difference. Something to consider.
The rotors are a very tight machined fit (no seals) so thermal expansion and contraction is their enemy. Compressing air makes heat so that is why you don't want a screw compressor cycling as it increases wear on the unit. I have found that one of the best things for reducing compressor noise on a piston unit is to slow the speed down. We have an 80yr old Champion 2stage 4cyl compressor at work that has been maintaining 225psi air for longer than anyone is left alive to remember. The thing only runs 400rpm which is probably why it has lasted and is one of the reasons it isn't real loud. It is probably half as loud as my 5hp Campbell Hausfield.
Your comment got cut off... How do you slow the speed down?
Change the pulley size. My CH 5CFM 30gal compressor uses the same compressor head as the 11CFM unit, but because it's a 110v compressor they run it at half the speed, produce half the CFM, and half the noise.
eformance That makes sense, thanks!
I love the older machines, my granddad's generation sure knew what they were doing....
there's a new fad about silent air compressors nowadays. one of their features is the speed is 1800rpm instead of 3600. The other feature is the cylinders and valves are large. (california air tools silent compressor for example).
Should have considered a Kaeser SM10. Has about the same capacity tank, but has a built in refrigerator drier, built in oil separator. Also has the computer built into it. We run print finishing machines with it and it’s programmed to run the motor continuously, but only compresses between 115-125. Love it!
Kaeser is a very solid brand. We have at work Copco's and Kaesers and Kaesers have been superior in reliability.
As someone who works in a field where ambient noise levels are disregarded. I like the fact you take into consideration both for hearing and safety the noise level in the shop on things that are controllable. Makes a big difference when you hear it every day.
The compressor should be in it's own room with cool air access.
Great video as always. For the home shop cheap version of the rotary screw compressor people may want to look at the quiet compressors from California Air Tools. They make 1 HP and 2 HP compressors that are about as loud as a laser printer - unbelievably quieter than the Porter-Cable pancake compressor I had before. It's possible to use one of these per machine and avoid the airline runs and they are very cheap to buy on Amazon. That gives me some redundancy too. It's great to have a quiet shop!
Proud of being an intern at Atlas Copco :D
GX5 as in 5KW is roughly 7HP - hence the name
Gx 5 is having 5.5kw motor power = 7.5hp
Basant ji nice reply
I work on a 240kw compressor
nightmare in action ji where ?
@@nightmareinaction629 I make the maintenance of 3 boge so340 of 250 kw from a client
I run out of my garage with a fadal 4020 so quiet operation is important to me. I looked real hard at the Kaesers when I started up. But in the end I couldn't justify the expense and went with a large two stage piston pump. It's not too loud and doesn't run that often. I did have to build in a poor man's dryer which consists of about 40 ft of copper pipe to cool the air before a drain valve and a water separator. But it works so well that nearly all the water that exits the pump comes out of the drain. Almost nothing makes it to the separator. If my shop was as large as John's I wouldn't hesitate to put a screw pump in though.
I have nothing like Your wonderful system (Mine are 2-80 gal tanks with one two stage compressor) but I am so glad I ran a loop too for various reasons. Very,very nice shop and congratulations for apparently doing so well. Dig the American flag in the shop !
i have one the same model at work . very good unit , very fast to refill with air .
We had several of these running in reverse, vacuum screws to operate the HP electronic board testing fixtures. They can really suck in vac configuration. The noise is the only benefit, and they do like to run continually. This was the secret of the U-boats, these screw style compressors were so quiet that it was extremely hard to track the U-boats by underwater electric running sound. The oil has to be special anti foaming screw compressor (super charger) oil, very pricey stuff. Good video. 3 phase fire pumps have a phase alarm on them to prevent the pump from running backwards.
Two of the Machine shops I have worked in so far have had the compressors located in their own little shacks outside. This is how I will probably do it as well. You can remote a starter switch or button inside as well.
Hi John, great video! Wondering, have you maxed out the capacity of this compressor with the addition of new machinery? Thanks in advance, and thank you for all the manufacturing tips and resources you provide!
Congratulations, machine is awesome and the air plumbing system looks great too. Hope you get many many years of happy use of them.
The main reason I have heard that continuous run screws are best, is because it keeps the oil hot and that prevents excess moisture buildup in it. which stands to reason, too many short cycles would make the oil milky, as it does in a car engine's cam cover if you do too many 5 min trips to the store, it's the coldest point so it goes all gloopy.
This is exactly right, although load/unload screws are fine too so long as they are sized correctly and the right size storage receiver is also used...this will keep the load cycles to a point where the heat in the machine is maintained...I generally like to see 165-185F and that keeps the moisture at a vapour so that it will pass the air/oil separator element...had a client once with a 100hp variable speed machine in place where a 30hp modulating machine was running at about 80% capacity (they got a good deal on it I was told)...and this machine normally takes 3/4 of a 20L pail of oil...was called in to see why it was constantly popping the safety relief valve each time it tried to cycle up...drained 2.5 20L pails of fluids from the machine...2 of those pails were water...this machine was running at a 'frosty' 125F peak.
We have a couple Ingersoll Rand Rotary Screw compressors. A 20 HP and 7.5HP one. We're in the food industry and so it's powering our 14 bucket scales, bagging machines, metal detectors and other things. There's a lot to do to maintain them. There's no computers in mine and are around 18 years old now. The 7.5HP is backup, but it doesn't keep up with our air needs. We also have a Air dryer our air goes through.
Aussie50 i
I wonder if that could be solved with an oil pre-heating system of sort.
@@FrozenHaxor they have a thermo stat on them so it would help only a bit. the best is to load them up and work em like they are designed.
Haha I made the same condensation catcher. I ended up using a evaporator cooler filter inside the bucket to make it even quieter. Now the air leaving the tank makes more noise than the air leaving the tube. :) Great video's always enjoy watching! BTW I have a Eaton PolarAir compressor (7.5Hp) has a oil pre heater, air dyer/filter, computer and auto drain, plus those guys have been great to deal with.
Excellent video and beautiful shop!
Good info. I never even thought of 'stale' air in the lines but that would make sense that you would get a dead spot with water build up. I think leaving on the pallet is a great idea, super easy to move if you need to repair something on it or just paint the wall behind it!
I double action compressor is more efficient than a screw but these tend to be really big, over 30 HP, monsters. Even a single action 2 stage compressor is still going to be at least as efficient as a screw. But the biggest, by far reason to run an air screw is duty cycle and life span. Air screws, buy nature, run a 100% duty cycle and last for many years (at least a decade). If you ran a piston air compressor at a 100% duty cycle it would be worn out very quickly, you need to keep them under about 60%. Even then you really are only going to get maybe 15,000 hours out of one before it's worn out. Compared to about 100,000 hours or so life on a screw it 'should' be cheaper to own as it has very little maintenance and will out last many piston compressors.
Thanks. Very useful info on screw compressors. Love your vids
The other nice thing about having a loop is that you can isolate any small section for maintenance or to make changes without cutting off the downstream part of your system.
Hey John very helpful vids.. do you know if there's a way to hook up mach3/4 to arduino mega, uno or nano?
Awesome video, awesome shop setup, and awesome dog! I had Vizslas growing up and now that I live in an apartment I can no longer have Vizslas, or a shop.
Thanks, You talked me out of looking into one. I buried my 5 HP 2 stage IR in the back corner of the shop behind some storage shelves. This keeps it quiet enough for me. I might try to pipe the intake outside also. Just need to keep the critters out of the intake tube.
Gonna be getting a Kaeser for my new shop, you're not joking about the price but I've had experience with them in previous jobs and they really are quiet. Thanks for talking about the distribution plumbing - I'm used to working with black iron pipe, gonna have to look at that RapidAir stuff for drops though.
Great video. I wish the first apprenticeship I had was as good a shop as yours appears to be.
Great setup! It is really quiet.
Just bought a KAESER for my new CNCs. Very useful video
Great great great great great video and info. Thank you so much.
On your shop noise question ... hard flat surfaces reflect sound very well. Soft or irregular surfaces absorb or deflect sound. That's why commercial office buildings have acoustic tile ceilings, carpet floors, and soft cubical walls. I have also seen individual panels placed in an otherwise hard room, to help mitigate some of the sound. Even cars and vans use carpet and padding to dissipate sound.
You could could use free-standing fire resistant acoustic tiles to form baffles around and over your equipment. Air will still flow well, and you can have plenty of space to walk through, but the noise level from other equipment would drop dramatically.
I've even seen bed egg-crate foam used as sound dampers. It's not pretty, and probably not up to code, but it works for cheap. You could use some to test the idea.
You'd want to talk to someone local about doing it, to make sure you meet all local fire codes.
As a person with tinnitus from hearing too much noise for too long, I wish I knew it was a fixable problem back then.
Hi John this is the type of equipment I connect automated controls to for Seimens technologies if you look on your air compressor it may have a RS485 or a Back Net connection on it if so you can install a Back Net / RS485 Management Module to connect to your Computer , just thought I would pass that on to you
I have my piston compressor hanging on thin ropes and it makes less noise now.
The ropes are elastic and absorb vibrations.
Our screw compressor does both, either suction-off-loader or shuts down when it gets bored. I love the ring main idea. I run some buffer tanks, but the main tank is huge as well. With varying air loads you can only have a best compromise. Thanks for the vid :o)
That thing is great. If you have problems with noise you could consider acoustic plates on the inner roof, makes the sound bounce 3-4 times before it comes down again.
Hi John, I'm looking for a compressor and came across your informative video. How is your compressor working out after 5 years? Did you have any issues with it?
Part of the reason why the screws like to run continuously is to keep the moisture boiled out of the coolant. The oil acts as a seal filling in the gap between the screws, so they don't actually touch. Also in the book for my 5hp IR screw they make mention of the starts and stops over heating the motor. Says if more than 8 starts an hour then turn switch to run continuously. One thing about the oil maintenance is that service intervals are quite high, 5-8k hours
You said 600'... lol. In our smallest shops ( manufacturimg and maintenance... ) we have over 600 DROPS, 200 - 220 operators, mechanics, technicians, fabricators, etcetera. All done in " screw pipe "... ASTM carbon steel pipe... that smallest building is over 1,800 feet long and 500 +/_ feet wide with numerous compressors. Even doing my proof house/prototype shop in town... was a pain in the pin feathers!
I will say, yours turned out like you designed it... and is functional and sanitary!
KUDO'S my friend, I realize this was shot 7 years ago... but still deserves a " pat on the back "!
Respectfully, Seth
Is your screw compressor belt driven?
I know on our one you could set manually set the "dwell" time.. this means less starting up.
Looks like a great job on the air system. There are phase meters so you know before you switch on if the rotation is correct. But it can be hit and miss with how import motors are wound and labeled. I just know that every time I hook up a 3 phase motor, it will be always running backwards. And now that I got a meter, I haven't had a chance to use it. On larger screw compressors they can also be driven with a variable frequency drive, so they run at just the speed needed to keep up with air demand and can run constantly, eliminating the starting and stopping.
Yeah, a small shop's air usage is all over the map. Sometimes nothing for hours, then practically everything on at once. No way to average that.
HOLY COW!!! technology in Zanesville.....how did that happen? born and raised there...even went to vocational school there FOR machine shop back when it was MAJVS. retired A.F. machinist and welder. good luck in the Y-city.
the sweeping bends are nice because psi is lost if volume cannot move smooth I had to learn all this because of my device.
Hi John
Great Video.
All I know is most Oilless type compressors will not stand up if they are used more than just blowing up a bicycle tire once in a while. If you have a Bead Blast Cabinet/Sand Blaster they will not last very long. Oilless units have plastic pistons/parts and cannot stand the heat of higher usage like what is required running the above equipment.
Cheers
Willy
In my previous job, they had 3 compressor,
2 working a fixed speed but only one working at a time as the other was used as a backup. And the maintenance service was alternating there use to level out the wear.
And a third with variable speed compressor ($$$) which was used to compensate the variation of pressure in the air grid (with the help of air tanks scatered around the factory)
Hi John A good reason for a motor not starting and stopping often is "hi current draw on start up and heat generated from start up. A motor will have a heat rating and will generate extra heat on start up this heat is usually dissipated while running.
Good luck with the new compressor you'll need it!
Nice clean shop
Great video. You forgot to mention who shouldn't use a rotary compressor.
You did a great job on that pipe. I have the same stuff in my MUCH smaller shop and I had a hard time getting it straightened. Yours looks great and nice and clean.
That piping system is sweet and user-friendly but im a fan of upunor or copper
That is one clean as hell machining workshop.
We have a screw compressor where I work and it is quieter than our old piston compressors. But not quiet enough. Our screw compressor is outside of the main building in a dedicated shed here in Florida. Its Way quieter! My piston compressor at my home shop is also in a dedicated shed separate from my shop and it's perfect! I can still hear it in case something goes wrong and I know when it's running , But it's not assaulting my eardrums.
Did you use the rigid pipe or the semi rigid pipe ? if you did use the rigid how did you make your radius bends in the corners and also in your drops ?
The 'Screaming Lena" rotary screw compressor the Huckleberry RR had was a Army government surplus unit. It had a Cummins diesel and would just sit and idle until we started using air then it would 'load' or reve up. We could use a 1" air impact wrench and it wouldn't load. This was at 90 psi.
DO NOT skeemp on air filters. I might add another filter to the intake.
I have a Quincy QP 7.5 that is an awesome machine but in a quiet shop it is LOUD. One thing I added to the system is a safety check valve right on the compressor output. It's a valve that will automatically close if a line or drop fails or more precisely a large pressure differential is sensed in the valve itself. Works similar to an electrical circuit breaker. It's peace of mind against having a flailing whip at pressure and having to run to a ball valve in a panic.
I have a 5hp Quincy, QT I believe. Love it. In my shop which is 30x32 open floor space, when the compressor kicks on, I can still hold a conversation within 10 feet of it. The pump is rated at 18cfm but it keeps up with my blast cabinet up to 120psi. I've never seen so much as a speck of oil come out of the tank, and I only get water when I'm running it hard for a while, like running the blast cabinet for more than 30 minutes. I can run a die grinder until it's frosty without any water issues. It runs slower than other compressors, and I do get valve noise, but it's not objectionable at all, and anyone older than 50 that wanders into my shop says it sounds like the old gas station air compressors.
Looks like a nice compressor. We had one about twice that size. I recommend venting the heat directly outside if you go any bigger than what you’ve got. Also keep an eye on that air drying system, they are a pain in the ass once they start to have problems. Also keep an eye at the outlet nearest the lowest point in your system that’s were water will typically collect if you have a problem, and boy does that stuff smell bad!
My answer to air compressor noise is to oversize the motor a whole bunch. Put a 3hp motor on your 1.5hp compressor and it'll be a lot quieter as there is more torque to drive through top dead center and it "knocks" a lot less.
a larger engine would surly make more noise...
electric "engines" are rather quiet
Greg Collins No.
Why not do this?
th-cam.com/video/zIQ_AM3bnwo/w-d-xo.html
Ave three phase air compressorb
Great info! Why not build a utility room with some good heavy block and concrete to house the compressors?
What kind of stuff you doing in your shop there? How many cfm the screw produce? The old polar is good, 30 cfm right? Did you need more?
Very nice compressor! Something to think about with any major addition is not so much the cost of the equipment, but more setup and future costs. You live in Ohio so there are probably at least 6 months where you need to supplement your heating(where the heat from your equipment isn't quite enough to be comfortable). I'm in FL and in planning my 1300sf shop, I have decided to keep my compressor outside under a lean to type shelter. I can't wait to work in the AC, but to avoid huge electric bills, I want to keep as much heat outside. Most people don't take into account that when they are in a cold climate, their 7.5hp compressor doubles as a 5KW heater. In FL where the AC is on 11 months out of the year, every watt used by equipment must be matched by at least a 1/2 watt to fight against the heat. That said, I don't think I could put a $10K air compressor outside. Over the life of my compressor the biggest cost will be the power to run it. If I had an awesome compressor like yours, I would need to get 20,000 hours(4KW@$.125kw/h) out of it to have the power bill equal the electric bill. Just something for those in warm climates to consider- The cost of keeping inside where it takes up expensive climate controled space. Those in warm climates need to keep things like this in mind- Might be time for a video on how to setup your plasma cutter so that the water in the water table is transfered outside after cutting.
Also, curious, does your state require a "Pressure Vessel" permit? California does when the tank is above a certain size and pressure (yours would be, plus you have employees). It's a $150 fee for 5 years at which the state comes out and inspects and verifies the tank is viable.
I've got a gx4 in my "hobby shop and i love it. I use a 1500 liter tank so that the compressor runs for a good while every time i use it
I have never had any problem with it being too big. :)
Its like i can get away with jobs sligtly too big for the compressor because of the buffer.
My dryer is between the compressor and the tank. My own idéa, I figgured hot air would dry better because of the bigger difference in temperature. I don't know if I did it right:)
Informative!
Mine doesn't have a computer but i can adjust the time that it runs after the tank reaches pressure. Mine is an IR unit.
the reason for running is that these units are contact cooled, that is that the coolant/oil is in contact with the screws and it also collects and holds on to water. The water can only come out when the coolant reaches a high temperature.
We skip the oil sampling and keep the warranty by having the mfg perform the PM services, which are about the same cost, just under 1,100 in the seattle, wa area
I wanna know does it work directly without extra tank? I wanna use it for car interior
I just bought a ga30 ff from a auction it was being used in a big fabrication shop, I'm trying to find out what it's worth??
Is there a check valve in line by that tee? You said air gets forced around if using air in that room so air dont get stale.
When you said "my wife caught me taking it home..." I was about to start the popcorn.
If you dont have a large demand for air rotary screw compressors might not be the economic option. They are more suited for larger shops or manufacturing facilities that have higher demand. You can buy them with a VFD that will slow it down and unload it when the demand is low.
Not sure if the tech is the same, but if you want a smaller quiet compressor, the Californian Air Tools compressors are the the most quiet compressors I have ever heard. I bought a small one strictly for my indoor lab. I have a 8 gallon piston compressor for outdoor work, but this little 1 gallon CAT compressor is perfect for indoors. Oil-less too.
Man, I am precisely working on setting up some lines for a new 3D printer and a CNC machine we are getting at the place. Good highlights!
thanks for sharing
The CNC shop next to mine (I use their air because I really only need it for paint guns and air sanders) just bought a new screw compressor because the old one died... it had low oil level and the guy who came to fix it said the wrong oil was used. He said screw compressor starts at 10HP, but it has a computer that basically keeps it on at slower speed bypass mode and it basically maintains about 7 bars at all times. The unit is also smaller and lighter compared to a normal compressor. The box for a silent normal compressor (basically a belt drive compressor inside a sound proof cabinet) was twice the size of a screw compressor of the same size. This can present a problem however as it takes 2 people to carry it and theft is a problem...
I did not even know these things existed till tonight!
Great Video! :-) Well Done
I am not a air systems expert just someone who has used them. From my experience a good piston compressor with a large storage tank with a drier or have a second storage tank for continuous capacity for somewhat intermittent use would be a more cost effective system than the rotary screw system. The rotary screw will put out a lot of air but is really meant for continuous use. Its my take. I worked where we used 400 psi and 150 psi with regulators for lower pressure as needed. There was a compressor building that housed the air compressors and heat exchangers separate from the main building because it was noisy around that building.
We have a 25hp screw compressor and a 40hp screw type vacuum pump. Both are over 20 years old. Neither has the computer VSD system but both go into stand-by (unloading the compressor section but continuing the motor running) when they reach set point. If demand lowers the tank pressure the stand-by valve closes and the compressing of the air begins again. There is a good electrical reason to do that. Motors pull a lot of power on start up all of which turns into heat in the motor. The second thing is there is an additional stress in the drive system from the impact of the big motors starting. If your electric company bills on a peak loading "demand meter" you may pay more for your power. Not an issue for a small motor like the 7.5 hp one you bought but... A screw system is ideally suited to a more continuous use shop than a piston type. Piston compressors get really hot if they run continuously. Not good for the oil, valves or motor. We service out machines rather than having a dealer do it. But it is still expensive. Every 6000 hours the separator element, oil filter, intake filters and synthetic oil will need to be changed. Check the costs of that before you buy, it may be shocking. We buy Mobile brand oil from an industrial distributor, much cheaper than the re-branded compressor company stuff. Our summers get hot so we have a separate air to air cooler between the compressor and the refrigerated drier. Our compressor has its own room to cut the noise, with lots of air circulation . The vacuum is in an out side shed with a big thermostatically controlled fan for summer and a heater for winter. You don't want a screw to start against cold oil. All of our piping slopes to drain points and all drops come off the top of the piping. It is also on a loop system that has ball valves that can isolate sections if needed. If I were start over, I'd have a separate room for compressors, vacuum pumps, driers, tanks, manifolds, filters, oil etc....... I'd also put in additional air tanks at the far end of the shop to even out peak flow. Again, plan ahead!
The aluminum pipe is nice, cheaper than our copper. Some people use Pex but there can be issues with deterioration caused by the additives in some compressor oils.
You may want to install an oil separator for the condensate drain to comply with regulations.
Having a back up compressor is always a good idea. We kept one of our old 10hp piston ones (over hauled) as a backup. Won't run the entire shop but will keep at least two machines running. If I was starting over I'd install two 15 hp screws with the simple timed unload system and both operated on an alternator, shifting between units on every start up. It would supply more air for peak loading and operate smaller motors at other times reducing electrical costs and demand charges. We have maxed out our 800 amp service so reducing the # & size of motors that need to start at one time might keep from having a very expensive power up grade. I wish now that I would have started with a 480 volt system. Now we have an assortment of step up transformers that waste power. Never expected to expand this much, plan ahead. This was a long post but it may help others avoid some of my mistakes.
Cool vid mate I look after 4 centac compressors, 5 atlas ZR comps 2 atlas ZT900, 20 kaeser ASD 50, and there is more Low pressure ones lol where I work the one you got will do you workshop great the dryer side are not so good but if in low humidity there fine where I am we have high humidity we got some huge dryers.
+NYC CNC yeah it would be cost we run all our ring main comps straight into dryers on 12" manifolds running out to an 8" ring main about 2km in length. Can see they would run yours with the tank so it can catch any oil that could get through the separator. When I'm in work next will get you a number of the auto drains we use for you to compare.
Personal experience in a combination dental office/large dental lab/insurance office building, 5 hp 2 stage compressor in a 3x12 foot room immediately adjacent to insurance offices and hallway.
1. Intake piped from outside building resulted in noise of compressor being limited to valves and gentle hum of motor which was 5hp, 3 phase. This was a Quincy unit, meant for supplying air to HVAC controls so low oil loss. Flexible SS hoses connected the unit which was mounted on rubber isolation mounts.
2. Air cooled air prior to refrigerated dryer, then stored in a tank. If wet air is stored in a tank it was my experience the tank corroded and the automatic valve plugged- very annoying.
3. If I recall, Quincy compressor approx $2K and about 21cfm/minute free air
4. If dependability is an issue, make provision for two compressors at time of installation - when that is an issue, add a second compressor. This has the effect to maximize return on capital. In business there is a capital/labor ratio. The more capital, the less the labor - as an owner you are labor.
5. If heavy surge air supply is a requirement, purchase a used surge tank. Large(depends on your definitions) seem to go for about $400 coming out of industrial settings, see HoffonLineauctions which is a good source of these things.
6. This air supply was further filtered in coalescing filters sufficient to be acceptable to run a dental drill(this was verified by supplier prior to installation) a well a a Comco blaster in the dental laboratory with no issues over a period of 30 years. The lab was the big user with blast cabinets that used the 20 cuft/minute air.
Properly maintained, the Quincy never missed a beat and is still running to this day in the same setting without issues.
Awww, look at Judd. He's such a beautiful boy!
I'm only halfway through the video and out of time to finish it right now, but in case anyone looking to make a purchase of this size is reading comments to learn more I wanted to mention that both manufacturers and dealers have reps who will come check out your operation and talk to you about your needs and make specific recommendations. Establishing that relationship up front is ideal for the long-term. Some will even bring and install a demo unit for a week so you can see how you like it. This is true of many kinds of shop equipment.
Bottom line: it doesn't always make sense to try to do all of your own research alone.
its the same as my ABAC compressor :-) great compressors. Oh and i love your Hungarian viszla i have 2 :-)
Screw compressors are the way to go. I'm about to upgrade my shop to a 100cfm variable speed IR so I can install some new machines. The compressor in this vid is great for running a constant air load but not so great for intermittent load. Variable speed units provide better efficiency over an on/off unit when used below full capacity. In my case a variable speed compressor is going to save me a ton on the electric bill. The downside is initial cost, and the added complexity of a VFD which makes it more difficult and expensive to repair should the VFD fail. Saw it happen when I was doing plant maintenance... cost 7k and 2wk lead time on a new VFD for a 25hp unit.
Exterior intake pipe.
Quincy had intake filters for exterior use with replaceable elements. This addresses keeping critters, etc. out of the compressor. From the compressor point of view, it is important to keep dust and grit out of it, think of an air cleaner on an automobile. We used PVC pipe for the intake line, probably 1 or 1.5" to reduce friction loss.
Surge tanks seem to be generally about 300-400 gallons to be worth while, heavy industrial settings have much larger tanks. If one were purchased used out of an industrial setting that was surplus to continuing operations and was stamped, there would be some assurance the tank would not be a safety issue.
My concern was always the tank rusting and then bursting - it seems we stored air at 175lbs/in squared. That is a great deal of energy in one place if the tank fails.
I have serious air envy!!!
John, while laying on the beach check out acoustic wall and ceiling panels for industrial noise control. The audiophile sector is, err, "passionate" about the topic, but if you can get past that, it may lead you to some inexpensive DIY type solutions using common insulation bats etc.
Short cycles are hard on them for a couple reasons. One - its a lot of mass and they don't have a vfd or a soft start and the shafts and coupling takes a beating. Also the contacts are prone to arc and suffer wear every cycle.
Also since the air is compressed progressively in the screw it is likely to experience condensation inside the screw as the rotors cool.
My 15hp Abac Genesis is being wired up today. This video made me sure to check out the manual on rotation direction, it turns out there is a phase sequence relay in the panel which will indicate if the phase direction is correct and I assume also prevent operation if it is not. The manual states that even a few seconds in the wrong direction can cause damage, that might just be to scare the reader or could relate to the specifics of that design. Anyway your video came at just the right time, thanks.
It costs more energy to start a part moving from a stopped state than it does to speed up a moving part that is already in motion (newton's law kinda deal)
also, if the screws are stopped, unless there is 0 backlash withing the drive gears, when you start it back up, they will reengage, and this can cause wear.
Or at least that would be my thinking on the start-stop issue you mentioned.
@ 7:41 on our Atlas Copco ZR900's we have bekomat auto valves- might like to look into those =)
THANK YOUR VIDEO,I SELECT NEW COMPRESSOR 👍👍👍👍👍
I use to make that type of compressor at Ingersoll. Very quiet and long lasting
Buying a screw compressor was one of the best things I have ever done. Our shop used a 10hp 2-stage 4 cylinder 120 gallon compressor for years. Before our CNC machines the compressor would only go on about 8x a day for about 3.5 minutes each time.
After the CNCs arrived it ran almost 50% of the time. Every 2.5 minutes the compressor would go on for 3.5 minutes.The noise was taking a toll. It was bad. It was worse than bad. (this in a shop of 2500 square feet... and no, there's nowhere to put the thing outside).
So, just for employee and the bosses sanity we bought a 10hp Kaeser AirCenter with the air dryer (it's a dry tank). Now I don't feel the compressor through the floor in the office or interrupting any conversations in the shop.
YES! They are expensive. YES! They have limitations but can sanity and hearing are worth more than a bunch of dollars.