Wednesday, March 26, 2008

Clean Water Production - Distiller

A few posts back we talked about the importance of having a clean water supply of your families survival needs. If you are collecting rainwater runoff for this purpose it would be wise to purify the water before human consumption. Here is the general process of distillation.

Every element can exist in three states: as a liquid, as a solid and as a vapor, which mostly depend on it's temperature. This applies to water, too. So, water can be found as ice, water and steam. If water is cooled down below 0 degrees Celsius (32 Fahrenheit), it becomes ice, and if heated above 100 degrees Celsius (212 Fahrenheit), it becomes steam. The temperature, at which a substance changes it state from liquid to vapor is called a boiling point, and it is different for different substances. This difference can be used to separate substances, and as such can be used for water purification.

The process is relatively simple:

a) the dirty water is heated
b) to the boiling point and thus vaporizes
c) (becomes steam), while other substances remain in solid state, in boiler. Steam is then directed into a cooler
d) where it cools down and returns to liquid water
e) and the end result is a water, purified of additional substances found in it before distillation.

Distillation is an effective process and, what's more important, it can be done with a lot of improvisation. You can heat water with whatever is at hand: fire, electricity, or whatever. You can use almost anything that holds water for a boiler, as long as you can direct the steam into a cooler. A cooler can be a long piece of copper tubing bent into a spiral. All you need is something that will just cool the steam down. In a worst case scenario, you can distill water with an ordinary household pot and two pot lids. Boil water in a pot covered with the first lid. After a while, you'll see that the water in the pot vaporizes, and condenses on the lid (this is distilled water). Now replace the lid with the second lid, and turn the first one vertically, so that all condensed water collects at one point, and then pour it into a cup. Meanwhile, more distilled water condenses on the second pot lid, so just repeat the above steps again... until you have a full cup.

Distillation will remove from water almost anything, even heavy metals, poisons, bacteria and viruses. However, it does not remove substances that have boiling points at a lower temperature than water. Some of these substances are oils, petroleum, alcohol and similar substances, which in most cases don't mix with water. Also, remember that substances removed from water remain in the boiler, so you'll need to clean it up every once in awhile.

Distilled water can be used directly and does not need to be boiled again. As it is already hot, you can use it to prepare tea, or similar drinks.


Blue Skye said...

When i was in the Boy Scouts (back in the dark ages) we learned to make a solar still with a sheet of clear plastic streched over a hole dug in the ground. A stone was placed in the center of the plastic sheet to make a low spot and a catch container placed directly below on the pit floor. The sun evaporated water in the moist soil of the pit and it condensed on the inside of the sheet, dripping into the pan below.

Boy Scouts then was a great survival school.

Blue Skye

The Scavenger said...

Another useful post Bear, thanks. In a pinch here is another way to distille water on the cheap.
Pretty easy way to get clean water.

The Other Mike S. said...

Pot or Reflux Stills can be a good option if you have a large amount of fuel, but generally aren't practical in an emergency situation (because of the need for so much fuel).

Michael Hawkins said...

You don't need a reflux still to distill water. Refluxing increases separation, but when distilling water, you're just boiling off the water to leave impurities behind.

But yes, even a simple still needs a lot of energy.

BigBear said...

Any evening except through the three hot months of summer I have a fire going at the cabin. Usually there is a cast iron kettle boiling just to release moisture into the air, very dry here. Just make your drinking water in the evening when the fire is going anyway.

In the city it would be more difficult especially without power.

The Other Mike S. said...

I saw this at survivalblog (I think) on how to make a homemade Berkey filtration system for a little over $100. Very cool. I just ordered two of the filters. 6000 gallons at 8 gallons a day (4 adults) would put this at 750 days, or nearly 2 full years.

tjbbpgob said...

I recently purchased an American made product (Aqua- Rain) for about 1/3 the price of the Big Berkley. I also found another one, complete in the box, at a thrift store for $4.00. Can you beat that? I still hate these little puzzle words tha make me prove I know my letters in order to post on these google sites. My rant

tjbbpgob said...

Opps, looks likwe I do need to learn my letters- - - T-H-A-T. GUESS I ALSO NEED TO PREVIEW BEFORE PUBLISHING TOO.

Anonymous said...

Um, hello? Calling Big Bear...where the heck are yah? Getting worried up here in Canada!

Anonymous said...

Another call for BigBear.
Where have you been ?

It's not like you to not post for this long !