Quote:
Re: Dust collection
Hi - Cyclones can be very simple, the longer the cone the better the extraction. Dyson have the problem of making a small extractor that can be carted around a home so they have lots of small cones. The "cyclone" with the cylinder will not work well as there is no velocity gradient in the system. Since in the case of a home or workshop extractor that space is not really an issue you can make a long cone with tangential entry and an exit central tube that comes down into the cone a bit and it will be very effective. If your into math there are many videos and descriptions on how to design these things. Its standard engineering stuff and taught in 2nd year eng.... They are generally clear for entertainment value you could make one from 3mm MDF or 2mm plastic quite easily...Peter
Hi Pete I have to disagree with some parts of your explanation of the cyclonic separation principles,
Quote:
cyclones work via 3 mechanisms 1) gravity pulls particles down. If a particle is small enough to float around in a room then a cyclone can't separate it and a filter is required. Some mdf dust is like this 2) air velocity creates drag on the particle and moves it along the ducting, when it comes into the cyclone it hits the cone wall and slows down, gravity pulls these particles down and they go the bucket 3) They can also reenter the air vortex but at a lower level. The air velocity is slower at the bottom of the cone then the top of the cone, they hit the wall again (due to the circular acceleration pushing them outward) and slow down again. At some point the drag is less then the gravity force and the particle falls out of the vortex into the bucket.
There are horizontal cyclones as well to save space, but verticals are more common...
To expand on Cyclone design, in theory any particle that is denser can be separated however some factors will effect efficiency.