Distillation is a sure way to remove all contaminants from dirty water. It works by boiling water into steam and the condensing the steam later on. Since all contaminants do not evaporate, you get clean water out. A problem with distillation is that it is hard to do on a small scale because often a small condensing coil doesn't condense much the steam. One way to combat this is to actively cool the condensing coil. In this Instructable I will use cold water around a condensing coil to make a mini water distiller.
I entered this contest into my local science fair. Below is a copy of what I submitted. I recived some amazing results, like a 44% increase in efficiency.
Step 1: Materials
Step 2: Wind the Condensing Coil
Start by making a winding tool by taking a 1.5-3in wooden dowel and drilling a 1/2in hole straight through the dowel at the end.
Before you start winding the coil, fill the tube with salt. This will prevent the tube from kinking and increase the rate of flow through the pipe.
Now, take the beginning of the copper tube and put it into the hole you drilled. Take the tube and slowly wrap it around the dowel. When you run out of copper tube, cut the tube close to its starting point.
Use water to disolve the salt from the pipe.
Step 3: Prepare the Bucket
First, drill a hole in the bottom of the bucket the same diameter as the hose gland.
Next screw on the gland into the hole (using plumbers tape) facing inside the bucket (see photo)
If there is not a water tight seal use epoxy putty to seal the hole.
Step 4: Connect the Tubes
Begin by fitting the silicone tube around an end of the copper coil. Use hose claps to ensure a watertight seal. The other end of this tube should connect to the gland in the bucket, your clean water output.
Now, Remove the whistle of the pressure cooker and fit a length of silicone tube to it. Attach the other end of the tube to the open end of the copper coil.
See the diagram for detail
Step 5: Running the Water Distiller
Start by submerging the condensing coil in the 5 gallon bucket with cold water. Put you dirty water inside the pressure cooker and start it up. You should be producing a steady flow of steam after about 10 minutes. Look closely for any leaks as it could contaminate your water output.
Yay! You should now have a steady flow of clean water coming out the output pipe. When the water in the bucket starts becoming very warm, replace it with cold water again, and put the preheated water into the pressure cooker.
Please feel free to comment with any ideas, questions or comments, and I will try to get back to you as soon as possible.