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ccw
02-09-2006, 06:19 PM
I have the roots 15 hp vac system.
I understand that the thing is rather loud.
I want to move it about 50'from the bot and put it in a sound reduced box. Understanding that the ambient temp can not exceed 120 deg.
Im wonder what effect on performance this will have, any thoughts?

Brady Watson
02-09-2006, 06:58 PM
Mark,
You will lose some CFM over the 50', especially if you have 90° bends. You might want to put it in a room(like a mechanical room), not a box, with vents top and bottom to let the air circulate.

-Brady

ccw
02-09-2006, 09:49 PM
Brady,
Are you aware of a formula that will give me some guidelines?
I will wind up with #3 90 deg. turns in the run.
I have a stair well that im thinking of closeing in to accomadate the louder pieces of equipment.
Either way thanks for the info.
Mark

Brady Watson
02-10-2006, 12:06 AM
Correction Factors for Friction Loss in 2" Vac Tubing:

-Sweep 90 ell equals 5 feet of tubing

-45 ell equals 2.5 feet of tubing

-Loss of CFM in 75 feet of tubing equals 2%

I thought that the loss would be more than this...The loss really stems from friction of the inner walls, but 3% loss is nothing. It's like 8 CFM or something with the 3 ells and 50' of 2" tube.

-Brady

gerald_d
02-10-2006, 12:45 AM
Most of the noise emitted by compressors and vacuum pumps comes out of their ports. A silencer/muffler on the exhaust port of a vacuum pump kills a heck of a lot of noise.

Brady Watson
02-10-2006, 01:20 AM
Even with the silencer attached these things are pretty noisy. The 15HP has it's own muffler...and it's about 4' long & 9 or 10" in diameter...If i remember correctly.

-B

trevor_b
02-10-2006, 03:09 AM
The pump I have on my system is surprisingly quiet - its easy to have a normal conversation over it.
Its 10hp and sucks really well. Its very noisy on start up, but once the thing is warm ( 5 mins) it runs sweet. Lots of "warm" air though.....!

I know this doesnt help Mark, but there are other options out there which are quiet.

Trevor.

gerald_d
02-10-2006, 08:02 AM
Trevor's pump:


3237
3238

3239
3240

Is that the exhaust port that we see on the last 2 pics?

Edited to say that the specs are here (http://www.becker-international.com/doku/detail.php3?ID=48) - yes, it is the exhaust port.

gerald_d
02-10-2006, 09:35 AM
Trevor, I would be a bit concerned about sawdust blocking up the cooling air channels of your style of pump.

Brady Watson
02-10-2006, 09:35 AM
Eww! I didn't know the new ones didn't have a muffler on them...I was thinking a 15HP Cascade...

ccw
02-10-2006, 10:50 AM
I will post a picture of the unit shortly.
Thank you all for your in put.
I will take it at this point that 50' will not be an issue.
Mark

trevor_b
02-11-2006, 02:29 AM
Gerald

I was concerned when i saw that grill to the right of the exhaust port, but this is not a serviceable filter - not sure what it does! The black housing on the top of the pump contains a paper filter to catch debris from the plenum side, and then the exhausted air is double filtered to remove any traces of oil mist. These need to be replaced every 2000 hours.The actual pump casing which is bolted on to the end of the motor is simply air cooled. I take your point that i will need to blow out the fins from time to time.We are a fairly clean workshop, so shouldn't be a problem!

FYI, the pump cost £3500 GBP.


Trevor

cip
02-11-2006, 06:50 AM
Mark;
If you have a Cascade 15HP roots pump like mine to say it's rather loud is an understatement. This thing will deafen you. I called Cascade and was told that they were working on some type of box that could be cut on the Bot to dampen the noise. You might try calling them to see if they have done anything yet.

Brady;
FYI my cascade roots pump has 3" pipe from the pump to the manifiold, I don't know if the fact will effect the lost calcs. but I would be interested in what you think.
My pump is currently under the table but I am thinking of moving it to another room to reduce the noise.

Mike

ccw
02-11-2006, 09:50 AM
Nope mine is a saber.
With the roots dresser pump.
I will definitely be putting mine in some sort of sound reduction booth.
Having a little sound proofing background I think I can reduce the sound by half at the very least will keep you all posted

Brady Watson
02-11-2006, 12:19 PM
Mike,
The 3" intake size is fine for the CFM of the pump. The whole idea of CFM loss comes down to air velocity and frition inside of the tube. The closer you are to the CNC, the better off you are...BUT I suppose that I would rather lose a little bit of CFM than lose my hearing.

On a side note, there are at least 4 different vacuum systems (pumps) sold by ShopBot over the years. The Becker pump shown above in the pics, is probably the quietest of the bunch, with the Cascade 15hp pump being one of the loudest...So when talking about your vac system, be sure to include what brand you (not you Mike...everyone) have. Some have baffled mufflers...others simply have a 90° elbow on them to divert the exhaust and others just have a PVC perforated tube as a diffuser.

-Brady

ccw
03-12-2006, 12:25 PM
Ok so now after all that and a bag of peanuts.
My electrical issues worked out.
I now am trying to get this thing running.
HOWEVER!........... I can no longer locate my manuel could some one please guide me to an online version of that book?
Roots Cascade 15 hp.

ccw
03-13-2006, 03:12 PM
Found IT!!