As I have said before, here and other threads---Vacuums pick up dirt by moving air. It is not suction. Orek used to advertise a small "Dust Buster" type of vacuum on TV by having it pick up a bowling ball.
The poor little ole vac was trying to move air. The bowling ball did not permit air to move; air could not get into the vac. So the system was static; no air and no dust moved. It would not be a good dust collecting system. We absolutely must allow as much air in as we wish to let out on its way to the DC.
The following is a fictitious example to help explain some of the air movement problems in a dust collecting system. If the DC system is really sealed except for the air coming out one 2 inch BS ducts, the system is grossly inefficient. I am feeding into a 6 inch main duct. I cannot move more air than I can take in so the air flow is choked. Therefore if I cut a hole in the BS wheel well (or leave a 4 inch port open) I can move more air. When I move more air, I move more dust. My system, which now has a 4 inch in diameter leak is more efficient than prior to the leak. In brief, I got rid of the bowling ball.
Please note the example is fiction. The real way to do this is to have an air velocity meter and static pressure meter in the ducting where the air leaves each machine. Then we would know not to use one 2 inch output from the BS. We could enlarge our plumbing and/or the number of places air gets into the system (bigger port, multiple ports, or whatever to make the meters read in the happy zone). As it was, my system was working perfectly so I had no concern about the fact that Glenn told me I was not going to need that port. I just didn't plug it until you guys (I did not see any female responses to this) got on my case. So I plugged it with a cold cream jar with a rubber band around it. My efficiency just might drop some, I don't think it can get better.
"No pic. It didn't happen." So here is the pic. I have to start a new reply. It won't take the last pic. JimB
Last edited by Jim C Bradley; 09-30-2011 at 03:51 AM.
First of all you have to be smarter than the machine.