Everyone has a different way of dewatering and filtering their WVO... here's some pics of how I'm doing it. I use 4 stages of filtration-- a coarse filter, a 20 micron water filter, and finish with 5 + 1 micron sock filters. Dewatering consists of heating the oil in a propane turkey fryer to around 250F. The oil I'm getting has very little water to start with and I only occasionally hear slight crackling as the oil heats up.
Stage 1 - These are simply fryer filters for the restaurant industry held by a basket made for them
Stage 2 - A 20 micron whole house water filter. These can stand temps up to about 200F but I have melted the elements at 250F. This housing seems to deform under the heat and leaks, hence it is in a pail.
Stage 3 + 4 - Final filtering is thru a 5 micron sock inside of a 1 micron sock, suspended inside of a plastic pail with a bottom drain that empties into my storage barrel. These socks have filtered over 200 gallons so far and still flow very well. As these filters are somewhat expensive, prefiltration with the coarse and 20 micron extends their life greatly. I bought the sock filters with the steel ring on the top and they suspend well from a hole cut in the pail lid.
A brass 12volt pump pushes the hot WVO thru the water filter and up to the final filters for gravity draining into the drum. This particular pump is older and I've replaced the shaft seal with Viton so it does not leak with 300F WVO running thru it.
I'm currently using a trans-fat free cooking oil that is supplied by ARAMARK, providing dining services to the campus of Bemidji State University. The ARAMARK staff have been wonderful to work with in setting aside this oil for me and they are totally on-board with the whole project as part of a campus-wide awareness of reducing their environmental impact. While ARAMARK has selected a trans-fat free cooking oil as a healthier alternative to saturated oils, it also has the benefit to me of being very cold-weather friendly with a low pour point. Using this oil, I have been able to run on vegetable oil at temps as low as -20F.
Saturday, April 5, 2008
Posted by Dan Houg at 12:41 PM