Lets do some math

[Bruce Seidner]

I have looked but have not found a way to calculate the loss of cfm and static pressure for a given volume of container. What, for instance is the loss of cfm/static pressure in a 30 gallon or a 5 gallon, etc, container?


I also wonder if there is a difference in the ratio of height to diameter in the efficiency of dust collection which is a different question, but one which would rely on a knowledge of the "cost" in static pressure introduced by a given volume of container. At what point is the convenience of a large container reducing the effectiveness of the separator?

And would the shape matter. Is there a difference in a tall and slender container versus a short and squat container that relates to efficiency of dust collection or in relation to cost in cfm/static pressure?

[phil (admin)]

All excellent questions.

Computing resistance would be a tall order.  I think it is much easier to measure it, and that is still a PITA.

But generally speaking, the small the D (diameter), the greater the resistance, and the better the separation.  The height of the container isn't that important in general terms, but could become somewhat important depending on total CFM you're attempting to reach.  So if you were somehow able to pipe 8" pipes into a 10-gallon container (very small), you'd find a huge hit to CFM.  OTOH, most of that would be due to the very nominal diameter of any 10-gallon container.