Vent fans are very nice. Essential if you are in a dusty / linty / cat furry / hot place. But the fan blades get clogged with the very schmutz you are trying to expel because the dirty air must traverse the fan. If there is a filter or screen that is even worse, protecting the guts of the mechanism but eventually clogging the screen and reducing efficiency. And then it must be cleaned off somehow. Bah.

The lintless duct blower has a hose from inside to out. Dirty or hot air moves down the hose and is expelled (into the side lot, where it fortifies the soil). The driver is a very strong air jet positioned near the distal exhaust end of the hose. The air to produce this jet is outside clean air and so less prone to cloggage. The jet enters the main hose at a steep angle, traversing the hose for a short distance before exiting the end. This produces lower air pressure in the hose segment proximal to the jet entry point. This low air pressure pulls air in from the proximal dirty / hot air side.

Dirty air does not traverse any moving parts with this scheme and no screen or filter is necessary.

This scheme will not work in circumstances where the intake and output is essentially the same airspace - eg cooling fan on a laptop. But for a large room with a hot server this would work well; ditto an industrial space.
-- bungston, Oct 18 2016

"Outside clean air"? https://www.google....VQKHZnBBz4Q_AUICCgD
Really? [Vernon, Oct 19 2016]

[+] this sounds a bit like a Dyson fan used as an extractor fan.
-- MaxwellBuchanan, Oct 18 2016


Or you could do the diesel routine and every so often send a flame through the duct to burn up the dust. No, nevermind, nothing smells worse than burnt dust, except maybe burnt cat hair...
-- RayfordSteele, Oct 18 2016


// / cat furry / //

You don't need a vacuum, you need a flamethrower.

// nothing smells worse than burnt dust, except maybe burnt cat hair... //

Just keep the flamethrower going until the smell of Napalm masks it.
-- 8th of 7, Oct 18 2016


A very nice thing about using olfactory stimuli with the Ludovico technique (should one wish, for example, to condition a positive response to the smell of cats) is that one can employ powerful sensory inputs from both eyes and ears for positive reinforcement and pleasurable sensations.

Also it is easier to position the clamps that hold the nostrils open.
-- bungston, Oct 18 2016


After which, it's entertaining to lure a cat out with a saucer of Milk Plus for a spot of the old Ultra-Violence ...

<wanders off humming "Singing in the rain" ...>
-- 8th of 7, Oct 18 2016


Nifty, it could also be visualized a little like dirt swirling down the drain from a slantwise air faucet (even though it is pressurized)
-- beanangel, Oct 18 2016


Hmm. Possible alternative: have a filter screen that is built like a conveyor belt, that passes over both sides of the fan. The dirt would catch in the filter before reaching the fan, then on the outlet side the filter would be blown clean again.
-- mitxela, Oct 18 2016


That's clever, you should post that. It would be great for equipment cabinet cooling. Some pharmaceutical processing filters work in a similar way.
-- 8th of 7, Oct 18 2016


//Hmm. Possible alternative// That, [mixtela] is a brilliant idea. If I could [+] an annotation, I would.
-- MaxwellBuchanan, Oct 18 2016


Two fans, side by side, one intake, one exhaust. Between them, an axle, driven by a geared-down motor, carrying a disc of filter material. Air is drawn in by one fan, through the filter. As it rotates, it passes in front of the exhaust fan, where it's blown clean. A duct vents the hot, dust laden air away from the equipment, where it immediately becomes Somebody Else's Problem.
-- 8th of 7, Oct 18 2016


Sorry, [8th of 7]; [mitxela]'s conveyor method is superior to yours.
-- neutrinos_shadow, Oct 18 2016


Misread this as "Listless duct blower" - like air-conditioning with added ennui
-- hippo, Oct 19 2016


In 8ths version if the rotating filter is between the fans the dust must traverse both fans. If the rotating filter is exterior to the fans then dust traverses neither.
-- bungston, Oct 19 2016


Yes, that's what we said ...
-- 8th of 7, Oct 19 2016


[8th]'s is the same as [mitxela]'s topologically. The filter is just a disc instead of a belt, and the fans are similarly unwrapped (though one fan and a couple of elbows would work too).
-- notexactly, Oct 24 2016


um, could you use an electret polymer for the fan, with a high preference for repelling most particles?
-- beanangel, Oct 24 2016



random, halfbakery