Home: Laundry: Lint
Self-cleaning lint trap for your clothes dryer   (+2)  [vote for, against]
Use water pressure to remove lint from a specially designed filter

Mainly for North Americans (we energy hogs of the world):

You know what a hassle it is to clean out the lint filter every few loads of drying. You’d think by now the manufacturers of these products would have figured out how to help us become even lazier, and hog more energy and resources….

I propose the following: A clothes dryer with an exhaust vent containing a filter that is designed to rinse during or after each cycle. Basically, the dryer senses back pressure in the exhaust stream (comparing the pressure before and after the filter), and runs a cleaning cycle every time it needs to. The airflow and heat would switch off, the filter inlet close, and a water jet would activate for a few seconds or however long needed (an optical sensor can detect water clarity exiting the filter). Dirty lint water would be drained down the same pipe the washing machine is connected to. Since such a small amount of lint is cleaned each time, there’s minimal chance of clogging the drain – same as a washing machine.

This would require a bit more plumbing, a couple of sensors and solenoids, but nothing too expensive. Well worth the price for the convenience.

Oh, and while they’re at it, why not use a counter flow heat exchanger to extract exhaust air heat and preheat the incoming air. Any condensation could now be used as a water source for the lint flushing system. This would save a HUGE amount of power.

<rant> I wish I could recall where I read this, many years back. I dunno if it’s even true: I read that GE dryers use approximately the same amount of power (nationwide) as the output of all their nuclear reactors combined. Pretty good scam if it’s true. </rant>
-- TIB, Jan 09 2004

Actually, I've always wondered why the dryer exhaust doesn't just go through a water bath to collect the lint. But, this is a great idea. A side benefit is that with a clean vent, you may actually see a net savings on energy costs. [+]
-- Klaatu, Jan 09 2004

Burn the lint and recycle the heat in the dryer.
-- phoenix, Jan 09 2004

My dryer vent does go through a water bath, at least in the winter, to put the heat back into the house. Counterflow heat exchangers are baked on some high-end dryers, afaik.
-- Freefall, Jan 09 2004

Aww, no quilt ... what is it with everyone crushing my dreams today?
-- Letsbuildafort, Jan 09 2004

[freefall]: You’re right, CFHX are baked on some dryers, but not in combination with a self-cleaning lint trap as far as I know. Adding that suggestion was an afterthought to the lint trap idea, mainly out of frustration that it isn’t mandatory on all clothes dryers. My dryer pulls about 6000W of electricity; enough to plough a small, aerodynamic, car down the road at highway speeds. There’s about 82 million clothes dryers in the US alone – very sad indeed. Just think of the reduced CO2 emissions we could achieve simply by making these simple devices more energy efficient. That’s an interesting system you have, and a good use of energy in the winter.

[phoenix]: When I suggested the self-cleaning lint trap to some friends, they said the same thing. After a little consideration, I decided to go with my original idea, just for safety. Imagine all of the built up lint in you dryer duct suddenly igniting – you’d have a solid (but fluffy) fueled rocket motor for a couple of seconds. Hang on, that’d be cool to see. Ok.. combustible lint it is ;)

[letsbuildafort]: If you’d like to use the lint from your dryer for something, I read that it works well when mixed with soil to grow strawberries. It does seem a waste to just flush it down the drain, or dump it in a landfill :(
-- TIB, Jan 09 2004

"Happiness is a drawer full of warm socks."
-- popbottle, May 12 2017

//Oh, and while they’re at it, why not use a counter flow heat exchanger to extract exhaust air heat and preheat the incoming air.//

Oooh! I'm building one of these. Essentially a large box with two baffles. Running between them there are 102 2.5" x 5" custom thin walled aluminum tubes*. Below the lower baffle there is a mesh raised slightly off the lower surface to create an area of dead air for lint to settle into, hopefully taking advantage of the cooling + expanded volume to slow the air stream down settling out extra lint. The input air winds it's way between the baffles outside the tubes in a kind of counter current arrangement. I promise I'll finish it when I find a more efficient way of cutting 2.5" holes.

I find the dryer thing a little infuriating in general. Not only does it use huge amounts of power, it also empties my apartment of all the warm air in a few minutes. In summer it's worse, I pay for the AC to cool down the air, then I pay for the dryer to heat it up again and eject it. Drying outside only really works for a few weeks in spring/fall, otherwise you end up with frozen clothes or pollen covered clothes.

*Beer cans with the ends cut off.
-- bs0u0155, May 12 2017

Well, clothes dryer lint is just about an ideal tinder material for starting fires. Why not just burn it off?
-- Custardguts, May 13 2017

You mean you don't ?

-- 8th of 7, May 13 2017

If the amount of lint is too small to clog the drain, why is there a filter in the first place?
-- MaxwellBuchanan, May 13 2017

// I promise I'll finish it when I find a more efficient way of cutting 2.5" holes. //

They make hole saws in that size. If that's still too slow: laser cutter?
-- notexactly, May 13 2017

Det cord.
-- 8th of 7, May 13 2017

random, halfbakery