going to 8" seperater

[alan m]

hi there
i started building my dc sytem with a smaller extracter that i had. it wasnt up to the job
so i bought a startrite 3hp 2bag
i mounted the impeller housing up in the attic above the seperater
the dc has a 8" inlet . i put a 8-6" reducer and 6" pipe down to the seperater

problem is i think im missing out on some posible cfm . im thinking that if i build a new seperater in 8 inch  and then reduce down to 6" with the ducting (already there but slightly changable)
hope fully the 8" seperater would alow more cfm
but any lost cfm would fromt eh seperater would be like having no seperater on the 6" size. hopefully i would end up with the inlet cfm i have now before the seperater but after the 8" seperater


will an 8" still work on a big metal barrel . 24"in diameter

also im thinking of puting a y straight away after the seperater in 8" and running this to my chop saw (a nightmare to extract from) the 8 " should help a bit better than the 6"

what do you think

[phil (admin)]

I think you will have to go for it and report back.

I do believe 8" can work on 24", though.  I think it is doable.

[alan m]

i think i will try it.
iv nothing to lose (ony 2 sheets of ply and a transition. )
i think iv got more to gain than lose.

what do you think is the best dimentional ratio for the transition.
im thinking that for a 8"round pipe. that maybe 10" high by 6" (5" plus a bit for the losses)
im thinking that the longer the better because it will put the dust closer to the side of the seperater and farther away from the out let

[phil (admin)]

Those proportions feel about right to me, as well.

[alan m]

i think im definetly going to go to 8" for the seperater and first outlet. hopefully the losses fromthe separater will be less than the gains by going up to 8".
now what to do with the 6 " one
its a shame to dump  so i will hopefullly get someone else hooked on phils system

[alan m]

im thining of building my 8"seperater 18" deep . the transition will be about 10 " so i will have 8 " below  the inlet to aid seperation

[phil (admin)]

How far back are you going to hold the outlet pipe from the baffle?

[alan m]

4" above the baffle

[phil (admin)]

So the outlet pipe will extend approx. 4" below the bottom of the inlet, which I think could work pretty well.