Double blower fan vacuum questions
Hi,
I'm setting up a home shop to etch and to carve flat items with a pressure pot-fed recycling vacuum sandblaster brush head. This is to avoid using a sandblast cabinet. Factory-built recycling vacuum sandblaster brush heads use a syphon type abrasive supply with a built-in vacuum. However my home-built vacuum sandblaster brush head will shoot the abrasive from a pressure pot instead. Pressure pots are reported to use about 60% less cubic feet per minute than syphons and are much more controllable. The other pressure pot benefit is that the blast nozzles can be easily switched out between a small low volume size for etching and a regular full volume size for carving.
Factory wet/dry vacuums are all too loud, even the Feins and Festools. Therefor my system will pull the grit and dust through a powerful, quiet homemade vacuum. Two blower fans plumbed in tandem will provide the vacuum. These blower fans are the ones used for huge inflatable rental bouncing houses for carnivals and parties. I have one already and it's way quieter under a fully occlusive load than the wet/dry vacs and it sucks at least as hard, if not more so. The exhaust from the first blower fan would therefor feed the inlet of the second blower fan. The grit and dust would be continuously sucked up from the sandblaster brush head through a six foot hose to a Dust Deputy, then though a simple air-gap water trap. After that the air leading to the blower fans should be pretty clean and would be exhausted to the outdoors.
I'm also planning to plumb in a switchable bypass around the second blower fan for when less suction is needed for the smaller blast nozzle. In addition, I'm planning to use a single motor speed controller for the blower fans in order to adjust the vacuum to the lowest speed that will get the job done.
Finally my questions:
Has anyone got experience with plumbing blower fans in tandem like this?
Does the motor speed controller idea sound like it should work?
