Thursday, June 29
Dewatering fabrication
I'm working on fabrication to solve the dewatering problem, which I've addressed in two ways, since there are actually two dewatering problems to solve - suspended (dissolved) water and separated water.
First, I need to get the suspended water out of the oil. After filtering out the food bits, there can be a substantial amount of water suspended in the oil, which is "dissolved". I've read several accounts on various Internet forums that point to rock salt as the common method for dewatering oil and diesel fuel, and rock salt appears to be a standard solution by the petroleum industry and fuel distributors for dewatering diesel. Apparently, salt will not bond with oil or fuel, but the water bonds to the salt, and becomes heavy, as brine, and sinks to the bottom. This will give me a layer of brine below the oil. I plan on achieving this by adding a good 4-6 inches of rock salt in the bottom of my filtering unit, above a filter I'll need to thread in. So, the oil will drip from the sock filter through
the salt bed, which should bond to any water, and give me a good layer of separation. When I pour off the oil, it should be easy (??) to not pour the brine into the 55-gallon drum.
However, there will doubtless be some water in the drum. In fact, I think there's about a gallon in there now, from the prior batch of watery oil I filtered direct into the drum. This will have suspended water in it, but at least it's only a minimal amount, and my brute-force method for final dewatering should solve it. The drum I'm using has a bottom bung, which is about 5" from the bottom on the side of the drum. I've installed a 2"-to-1" bushing, 1" x 4" nipple, and a 1" tee. Coming up from the tee is a 1" brass ball valve, and straight
out from the tee is a 3500 watt heating element designed for a water heater, which is threaded in and sticking about 12" into the drum.
It's not touching the fittings, and is largely inside the drum. I plan on using this to heat the oil in the drum sufficiently to boil off the water into steam, and have an auto temperature gauge to
install in the drum, if I can just figure out how to install it. I think I can drill a hole in the drum and screw it in with a nut and O-ring inside the drum, and O-ring outside the drum, provided it's an O-ring that can take the heat.
I think the best way to manage the steam will be to screw a nipple into the 3/4" fitting in the lid of the open drum, put an elbow on it that will take it 5" over to the side of the drum, then to a T that is pointing up and down. I'll put a 2' pipe going down from the T, with a bucket below to catch water dripping, and put a 3' pipe going up for the steam vent, so the steam doesn't hit someone.
I'm wondering if I'll also need a coil below, to condense the steam, and keep it from causing burns?? Decisions, decisions. I guess this is why it's called "fabrication" instead of building from a kit. Imagination, creativity, risk and experimentation are all part of the mix.
