Boyling your clothes dry

[pierhogunn]

Okay, my math and physics geniuses,

it is possible to use a vacuum pump to dry your clothes

lets assume that a load of wet clothes weighs in at 50 lbs
the temperature of the clothes when we straight out of the washer is 50* F
and that moisture content of the clothes is 50% or better

can you draw a hard enough vacuum to evaporate the moisture out of the clothes without applying the same amount of heat that a regular tumble-dryer uses?

[LinuxRandal]

Space is a vaccum, and the flow of air out of the bag, would have a chilling/freezing effect by my thoughts. (kinda like compressed air)


This may be different, depending on where you did it (tempeture variables)

[BobSch]

I would think that the reduced pressure would lower the point at which the water would evaporate. This would cause the clothes to dry assuming the pump was left on to hold the vacuum.

[LCHIEN]

yes it would probably dry your clothes quite well.
The issues i can think of, you need to pull the initial vacuum gently lest all the clothes be sucked out into and jam the outlet where the vacuum is attached.

You might get a very wrinkled batch of clothes compared to a tumble dry permanent press cycle in your dryer. I'm thinking more like a prune-like wrinkled finish, like fruit in a dehydrator (which is what it is after all).

But the clothes would be very dry, water boils off (and doesn't raise the temperature) quickly in a vacuum.

[bruce hylton]

You can freeze them dry, why couldn't you vacumn them dry?

[cabinetman]

They may dry faster if there was some sort of air flow, even if it's minimized. A controlled vacuum may pressurize the air through the fibers.
.

[crokett]

You might get a very wrinkled batch of clothes compared to a tumble dry permanent press cycle in your dryer. I'm thinking more like a prune-like wrinkled finish, like fruit in a dehydrator (which is what it is after all).

But the clothes would be very dry, water boils off (and doesn't raise the temperature) quickly in a vacuum.

Loring, I am not so sure you are correct. The wrinkles in clothes are because the cloth is creased. You are boiling the water off in a vacuum. A dehydrator (at least my mom's) works by blowing warm air through the fruit and evaporating the moisture. Also, the water in the clothes is not part of the fabric so with wet clothes, the fabric is unchanged, it is just wet. With fruit, the water is part of it and when it dries it shrinks. You get the wrinkles because the surface area is smaller and all that stuff has to go somewhere. A shirt hung on a line to dry doesn't wrinkle if it isn't already wrinkled.

[DaveS]

I detect a Mythbusters episode in the making here...

[Tom Miller]

Forget the clothes for now (), and just think of a vacuum chamber with some water in it (at some temperature that will remain constant). As you pump the gas out (it will be air with water vapor at first, changing over to just water vapor), the pressure of the gas over the liquid will start to decrease, upsetting the equilibrium. A new equilibrium will be reached by more liquid vaporizing. But your vacuum at any given time, will be limited to the vapor pressure of gas over liquid for water at the given temperature, until such time that you have pumped all the water out of the system.


Regards,
Tom

[rjwaldren]

I agree with Crockett, the clothes would dry in the shape that they are placed in the container. If they were hung they would be unwrinkled.

As far as drying, of course it would work. It's exactly how they remove moisture when charging an A/C. Pull a vacuum on a closed system and the water will vaporize and be drawn out by the pump. If the pressure rises when the pump is turned off then there's either a leak or moisture still boiling off to fill the space. If it holds steady the clothes are dry.

I used to purge moisture from aircraft systems by purging with dry nitrogen gas.


While it would work, I doubt it would be anywhere near as efficient as a good ol' dryer, much less a clothes line.

[jackellis]

Answer to part of the OP's question is yes, you can use vacuum to dry clothes. However, you'll probably use more energy and more costly equipment to pull enough vacuum compared with a clothes dryer or a clothes line.

Bottom line is, vacuum will work but it's probably not worth it unless you have a lab full of the right kind of equipment at your disposal.

Question back to the OP: why do you want to do this?

[master53yoda]

can you draw a hard enough vacuum to evaporate the moisture out of the clothes without applying the same amount of heat that a regular tumble-dryer uses?

Yes you would have to apply 940 btus per pound of water removed whether you did it in a vacuum or a pressure chamber. the only thing the air pressure or vacuum does is change the water's boiling point. the vacuum does not boil the water off, the added btus do.

[pierhogunn]

Answer to part of the OP's question is yes, you can use vacuum to dry clothes. However, you'll probably use more energy and more costly equipment to pull enough vacuum compared with a clothes dryer or a clothes line.

Bottom line is, vacuum will work but it's probably not worth it unless you have a lab full of the right kind of equipment at your disposal.

Question back to the OP: why do you want to do this?

I've always been intrigued by the idea of the ultra-sonic washing machine and vacuum powered dryer. If these 2 technologies could be made to work together, you could have a single machine that would have a wet cycle and and a dry cycle, it would use very little water since you could capture most of it from the vacuum, and filter then recycle it

My idea was something like a cassette based system where you fold your dirty clothes, put them in a basket, and then just slot it into the machine. When your cassette was done, you just put this back into your storage area and float back to your work ( on the ISS, or other place in space)

I used to imagine what it would be like to function in space, and the one thing that I never hear on the space documentaries is how the keep their clothes clean, using the toilet, sure, plenty on that, but what if you miss, and you get an embarrassing brown spot on your jumper?

This is an idea that I have toyed with in my head since I was about 13

[cabinetman]

I used to imagine what it would be like to function in space, and the one thing that I never hear on the space documentaries is how the keep their clothes clean, using the toilet, sure, plenty on that, but what if you miss, and you get an embarrassing brown spot on your jumper?

This is an idea that I have toyed with in my head since I was about 13

That's easy. Their jumpers are coated with a Teflon® based Scotchguard®. Nothing sticks, not even you know what.
.

[cgallery]

Instead of a cassette full of garments, how about a single garment at a time. Wash + dry in 2-3 minutes, ready to wear. You come up with with a device that can do that for $1 a use and mount it in hotel rooms, dormitory rooms, etc., and you'd have a gold mine.