Paul,
Bit of advice for you, if you interested!
This is the basis of a good idea in theory, but most food outlets would prefer you to take there used oil away rather than filter it and re-use it.
Im not sure, but I think `Filter Fry` only clean the oil rather than deep clean the equipment it was cooked in, so its definately a opportunity as a add-on for your oven cleaning!
Personally, I would get in touch with a sheet metal fabricator to build you a tank, then you can add pumps and filters etc.
A trolley based tank that fits through standard doorways is a god send, as you can easily cart the oil away and pump to another larger tank on your vehicle.
The waste oil you collect and clean can be re-sold to independant bio-diesel makers, im sure there are companies out there that would buy this from you at wholesale prices!
Trust me on this, I work part-time in maintenance for a large chain
of health clubs, and its murder trying to get a reliable company to collect waste oil on a regular basis for reasons of access/storage & security problems, plus which you can charge for!, but you should see your local council about a waste carriers license.