Quote:
Originally Posted by numbskull
This stuff confuses me no end.
As I understand it, larger ducts are more efficient, but require higher HP blowers to maintain air velocity high enough to carry chips, which is why most home shop collectors are designed for smaller duct work. For 6" pipe you may be looking at 3-5hp machines. You also need to upgrade the dust bags (both quality and surface area)to handle this increased pressure (or the dangerous small dust gets blown right through). Finally, most good systems now make use of a cyclone to reduce bag clogging. The cyclone has to be designed specifically for the HP of the collector. Even then, capturing the dust/chips at the source becomes a nightmare.
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the main purpose of a cyclone is to cut down on the debris passing through your impeller , thus landing in a collection bin instead of a bag that needs to be cleand/emptied
I actualy have charts and formulas for figuring this stuff out.. I'm already running 1 micron 40 gallon bags( which even when cleaned, have a shelf life) and a cyclone pre sepperator...my blower wheel is 11.5".. and free wheels at 3450 rpm's.. and even though the port is 4" it moves a sufficient volumne of air..... the smaller the pipe, the more resistance, the more turns/"t"s the more resistance.. branch speed should be approx 400 fpm.. main trunk approx 350fpm.... all that said, I wanted to upgrade to a canister type fine dust filter instead of a pair of bags( a royal PITA service).... in the end, the cost of a new canister, was half of a new unit.. I just ordered a 2 HP, 1500 cfm unit.... with 1 mic canister filter and disposable 60 gallon bags.... DONE!