Size of outlet hole

[corydoras]

Hi I built this separator for a trash can, and iI have a huge 3 hp blower that I am going to connect to it.
The size if the separator is 430mm inside diameter, and my question is: how large is it possible to have the center port (outlet) without distorting the cyclonic effect.

You see my blower has an 250mm inlet port.

Do I have to build a bigger seperator and collector can?

Hope someone can help

best reg
Cory

[alan m]

if your dc has a 250mm inlet then i would go with that if you can. the more you reduce that down the more cfm you will loose
430mm is very tight . i dont think it will work as well as it could.
you will only have 90 mm on either side of the outlet.


on my 6"top hat i am using a large steel barrel. it is about 20" or 500mm in diameter. i have about 175mm on either side

im about to build an 8" version that would have 150mm on either side.  i thought that was pushing it a bit .
i think 90 mm might be a bit too small.



what size inlet have you
given that it is already built
im not sure what is best. you will lose either way.
my feeling is to open the outlet out as large as posible and hopefully that will counter act some of the losses that the seperater will create


post some pics. we all love pics

[corydoras]

Thanx for the answer Alan

I built the top hat to fit the size of the barrel, but I see as you state that 90 mm on the outside of the outlet might be to little.
Might have to build another one, with a square collecting container under the hat.
The other problem I have is the ceiling height in my basement. This is only about 200cm, ad below this is the piping for my heating radiators around the house.
Beeing only 178cm i make it, but as you might tell I have no room for 6" piping. i was considering 2 4" branches in paralell, but I am not sure. My TS could hava a 4 inch on top and bottom, and the same goes for my Router table and SCMS.

My jointer and sander does not need this much airflow.

But a 4" line would create a lot of static pressure loss, but running 2 lines might be better than one?

My intake is 180mm x 180 mm

I did not build this top hat from any drawings, so it might not be correctly consructed.
The dropslot is 28 mm wide and 240 degr, but I see on other builds  on this page, that mine might start a little close to the intake.
I do not know if this has any effect on the drop effect?

Any ideas?

Here are some photos from the build, if this is of any interest.

The 4"port is just temp for testing an my old single stage dc

Please lead me in the right direction:)

Best reg
C

[alan m]

the build looks ok.
i would thin down the thickness of the baffel around the slot. i 45 degree chamfered mine and then sanded it  a bit more. that should help a bit

why have you no room for 6" pipe. 2 4" pipes will have a lot more surface area than 1 6" pipe so the losses will be higher


i would build an 8" (200mm)transition (closest to area of 180mm x180mm) then dop down to what ever you want then


even with an 200mm transition  inlet to the seperater you are loosing 33 % surface area and gaining whatever losses are acosiated with that

my seperater is about  135 cm high roughly. my 200mm version will be a lot higher (its transition is 6" x10" and it will be double height so at least 20" or 500mm)




if time and money are there i would rebuild to 250mm inlet and outlet ports.
then you can add what ever ducts after that.
remember that it takes 6 100mm pipes to have the same area  as 1 250mm pipe

[corydoras]

I might just start over and build me another one, what size do you suggest for diameter, inlet and otlet port, and also height?


best reg
cory

[alan m]

the diameter will be defined by the container you can get. the larger the better

the inlet /outlet port . i woul go with 250mm . down the line it will be easy to add extra lines or upgrade. too small and you will have to build again

the height. im going to build a double height  seperater. mine will be doubly the 10" of the transition.
the area of a 10" pipe  plus 20% for losses is 78.5 sq inchs
so a 12"x 6.5" transition would work perfectly


the problem here is your low ceiling.  i would get the barrel and mount the dc as high as posible then measure how much room you have. i put some 2" casters under my barrel 
you would want a few inchs of flex hose joining the seperater and dc to allow for isolation of vibrations and enough room to remove everything
i would make the seperater as high as posible. the more height in there the better