Cyclone Separator for a Shop Vacuum
by RockstarAlchemist, published
First attempt at a cyclone design. The goal is an inline cyclone for my ShopVac to catch the saw dust that clogs the filter of the vac. Simply mount the base over a hole on a five gallon plastic bucket. Attach the top outlet to your shop vac and the inlet on the side to your business end. The angular momentum of the higher density saw dust should circle the cone and fall into the bucket, while the clean air passes into the vacuum. Presumably this design could be a hydro-separator, too, for those familiar with the mining industry.
A nice Wiki article: http://en.wikipedia.org/wiki/Cyclonic_separation
There are seven parts to print for a high efficiency cyclone:
- Inlet X 1
- Outlet X 1
- Upper Cyclone Body X 1
- Lower Cyclone Body X 1
- Coupling Ring X 3
- Mounting Base x 1
- Body Tube x 2
This really tested the limits of my Printrbot LC+. The Lower Body is 197 mm high. You're welcome to scale it down, but the hose couplings are sized to mate directly with a standard ShopVac hose.
I used 3M x 10 hex bolts.
Based on the this data set for high efficiency cyclone design: http://www.aerosols.wustl.edu/education/cyclone/section06.html
Parameter //Recommended //Theory //Original //% Diff
D= Body Diameter //1 //144 //144 //NA
a= Inlet height //0.5 //72 //50 //-31%
b= Inlet width //0.2 //28.8 //50 //+42%
s= Outlet length //0.5 //72 //70 //-3%
De= Gas outlet diameter //0.5 //72 //44 //-39%
h= Cylinder height //1.5 //216 //70 //-68%
H= Overall height //4.0 //576 //267 //-54%
B= Dust outlet diameter //0.375 //54 //44 //-19%
Based on this theory the low hanging fruit here is to increase the height of the cyclone. I will generate several tube inserts (cylinders with ID=150mm and 3 mm thick walls and 150mm high). The same Coupling Ring can be used to join the sections.
Next for consideration will be the inlet shape. Something to force the dust into the cyclone wall ensuring is has high angular momentum along the cyclone walls. I think the depth of the Outlet length (s) is sufficient. My hope is to not have to reprint the upper cyclone body.
OK, It's complete and it works!!! The first dirt photo was a test of general junk around the shop. Very high efficiency was achieve, but the larger pieces clogged the outlet the bucket (it caught it nonetheless). The second setup was for saw dust on the table saw. Again, worked like a champ. I think the only real debris was what was stuck to the filter in the shop vac before.