Dust Extraction Problem

rexel2

Hi all,

I have a twin bag 3hp dust extractor with a 9inch outlet. I wish to run 3 machines off this (all 3 have 4inch outlets). I put on a 9inch to 4 inch 3way connector direct to the extractor and ran 4 inch hoses to each machine. The suction is greatly reduced when even running 1 machine on its own.

The machines are no more than 3 metres from the extractor.

Would taking a 9inch run from the dust extractor and only branching to the machine with 4inch be a better option?

Could somebody please advise if I am doing something wrong or what is the best method.

Regards

mazthespark

mite be because its always drawing air from 3 locations. if u were to close off the ports u werent using at that time maybe that would improve it. blast gates could be made or bought to solve the problem of having to remove hoses and block holes if that worked.

jack of all

As Mazthespark says blast gates are the answer. I think I've seen them on Axminsters site; they're not cheap but would mean a huge improvement in performance.

rexel2

Thanks for the replies.

Ya the 3way connector has close gates on it, so I only have the 1 gate open at a time. It just seems to lose considerable suction when down to the 4" hose compared to when it has a 9"

galwaydude18

Have u checked the 4inch for any air leaks? Might be worth checking out.

Carlow52

from here:
http://www.engineeringtoolbox.com/darcy-weisbach-equation-d_646.html

if u put in .1m and 3m in the first formula here u will see the effect of length and diameter

It drops by about a factor of 8 !

ps u dont need to understand the math, just change the length and diameter