Filtering WVO
Step 1: Find a restaurant willing to give the oil to us
Step 2: To make sure the oil does not have water in it by doing a Sizzle Test
Step 3: Pump oil from bins into our cubies. We filter out all the large bits this way with a sock, and now jeans.
Step 4: Pump from the cubbies through our filters to filter down to 5 micron.
Step 5: Wait & workout
Step 6: You now have fuel
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Cleaning Station v2.0
We have now acquired some "cubies" these are about the size of our previous buckets, but now we can fit more on the back deck. They are also easier to handle and clear to allow for good viewing of the oil when pumping.
The oil is tested using a "sizzle test". An oil sample is taken and placed on a hot pan, if the oil bubbles, then water is present. If it doesn't bubble, or just a few small bubbles, then the oil has a low enough water content to be safe. We learned this lesson after pumping about 15 gallons of oil with a high percentage of water into the tank. Then, this oil had to be drained and disposed of.
The curent cleaning process is to pump oil from the restaurant bins into our cubies. Next, we let the cubies settle for a day or two while visiting the town. The "black box" is our cleaning station, consisting of a pre-filter and post-filter utility pump. The filters are home water filters with 30, 10, and 5 micron filters between the two pumps.
Here is a close up of our filtering station. It pumps about 50 gallons per hour, max. So, it isn't too fast when our tank is 70 gallons and we have 30 gallons spare sitting on the back. But, it is cheap and reasonably quick for the size and cost.
8 cubies, giving us much more fillable space than the previous 4 buckets
The back is getting pretty clustered
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Maiden Voyage
The dual-tank setup has been completed, and waiting for oil for weeks. Finally, oil was given to us by someone who had been collecting it for conversion to biodesiel. He no longer had use for it, so we took it off his hands, and the day before we are to leave for a cross-country journey, we get to test out to see if it will run on the veggie oil. After a quick stink down US-441, we were unsure if the switch to veggie even worked. Flipped the switch, and waited a few minutes, nothing seemed to change, the fuel temp stayed at about 140F. We climbed under to make sure that veggie oil was flowing, then noticed the scent of a fast food restaurant coming from the tailpipes... Success!
...Then... failure. The fuel lines had hit the exhaust and melted through, after a quick fix, Sunshine was up and ready for another test run, this one without any issues.
Collected veggie oil, with sediments settled on the bottom pretty well
Pumping station going
Pumping station
I'll have more info on this soon. It is basically three home water filters 20, 10, 5 micron, then a diesel/water separation filter 10 micron, and a utility pump to pull it through the system. We found the pump didn't have enough power to pull it through the filters, so making a funnel out of a bucket and using gravity fixed the issue.
Is it running on veggie?
Veggie temps getting warm, however I think it still needs more heat.
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Waste Vegetable Oil Conversions
Diesels were invented to run on peanut oil and it does not take much modification for most what we now consider "older" diesels to run on vegetable oil. The main issue is that vegetable oil (VO) is much thicker than standard diesel. However, at around the boiling temperature of water (100C), the VO is nearly the same viscosity as conventional diesel is at the freezing point of water (0C). So, we want to heat the VO to around 100C/212F. An easy way to make the VO less viscous is to heat it.
This heat can be added via electric heaters, or by using excess heat already created by the engine. Conveniently, combustion engines are quite inefficient and create plenty of excess heat that is transfered into the cooling system. This heat from the cooling system can be captured and used to then heat the VO.
Even with these methods of heating, it takes time to heat the VO. Many conversions utilize 2 tanks. One tank holds diesel and the other VO. The engine is started on the diesel until the VO can reach an acceptable temperature. Then, before shut-off, it is switched back to the diesel tank to clear the lines of any VO. This way, on the next start, cold VO is not clogging the lines.
Any VO conversion is best when it is tailored to fit the driving situation. This is on a motorhome and will be mostly used on long drives; so that will be taken into consideration. This conversion will utilize several heating steps. The original 70 gallon tank will be used to hold the VO. The first heating stage will be to run the engine coolant back to the tank and have it run through copper piping inside of the tank that will act as a radiator, diffusing heat into the tank. Next, the VO will exit the tank once warm and enter a separate fuel filter only for VO that is heated by the engine coolant. This gives it another chance to reach a higher temerature, and also heats the filter, helping to heat the VO that is left in the filter from the previous start, as this is not cleared by diesel on a purge shut-off. Finally, the VO will go through one more heat source, a flate plate heat exchanger (FPHE), just before entering the injection pump/engine. This is to make sure the VO is heated to temperature after running through the fuel lines. Also, at this point in the fuel line the diesel also runs through the FPHE. While the diesel does not need to be heated, and should not be heated too much, by heating the diesel, this will heat the injection pump and all the injectors/lines. This way they are all warm when the VO is switched on. If the injection pump and lines were cold and the hot VO ran through them, then it could cool the VO to the point where it will be too viscous. With the 6.2L chevy diesel the injection pump is known for breaking the shaft in this situation. So, this step should avoid that issue.
Parts list:
- 16 Gallon "below-deck" marine fuel tank
- (2) 3-way 3/8" solenoids (for switching fuels)
- Electric Fuel lift pump w/ 3/8" connections
- 3/8" fuel line
- Racor Diesel Marine fuel filter w/ water separator
(R90T)
- 15 plate brazed heat exchanger w/ 1/2" femal NPT threads
- Custom fuel heater using glow plut to supply heat and disc thermostat to control temp
- 1/2" heater hose to route coolant heat exchanger and heated fuel filter
- Switches, wires, relays and fuel temp gauges as necessary
Diagram of VO/fuel lines:
