The Appleturnover Biodiesel Processor
By Rick Da Tech
The traditional Appleseed Biodiesel Processor will trap a few liters of liquid in the bottom of the processor. Most people don't find this to be a problem, but some have decided to reduce the liquid trapped in the processor by turning it upside down. Water heaters have a domed shaped (convex) top and a shape similar to a wine bottle (concave) on the bottom.
In reality, the glycerin left behind in the processor will help, in a small way, the next batch to be of a higher quality by absorbing water and increasing the methanol's solubility in WVO. That is unless your WVO has not been sufficiently settled to remove the trash. Once the reaction is over and the settling process has begun, the trash from the WVO will settle to the bottom of the glycerin in that region that does not drain properly, building up with each successive batch. This trash cakes up on the heating element causing heating elements to burn out prematurely, after only a few batches. There are a lot of solutions to this problem, including the Apple Turnover.
There are typically three and sometimes four ports on top of a typical water heater and when flipped upside down, they are near the center at the lowest point of the processor providing a near complete drain. The typical Appleseed has its lowest drain on the side of the water heater several inches above the lowest point. The AppleTurnOver biodiesel processor, as many call it, not only has the advantage of more complete draining than the traditional Appleseed, it dramatically increases the number of usable ports on the bottom of the processor. These extra ports add flexibility and increase the number of design options available.
In the simplest form of the Apple Turnover (above) one drain on the bottom goes to the input of the pump and the rest are plugged. A sight tube will either come off the TNP hole or off one of the holes on the bottom of the tank that goes up to what was the drain. The old drain that is now the highest port on the tank is used for both the vent and the top connection of the sight tube. The output of the pump will pump to what was the lower heating element hole. Methoxide is injected just before the pump in the same manner as an Appleseed Biodiesel Processor.
This is very nearly a classic Apple Turnover. Being made from a solar storage tank, it only has one heating element in about the middle of the tank. In order to make this turnover a new port was drilled and tapped in the very top (was bottom) of the tank for a vent to make up for one less port available with the solar water heater. The top of the sight tube connects to this vent and plumbed it outside. The bottom of his sight tube is connected to the original TNP port.
The circulation line looks very much like a typical appleseed that has been upgraded to a steel return line. Note that he has given up the wooden platforms in favor of non-flammable cinder block supports. All in all a simple design combining the best of KISS and safety.
Bob Abbey's 80 gal. Double Pumper Turnover
As it turns out all those extra ports on bottom are an irresistible temptation to try new plumbing arrangements not possible with the traditional Appleseed. Bob Abbey has gone with two pumps on this one. By using two of the inexpensive little blue pumps he is able to double his flow rate and dramatically improve mixing. The two little pumps cost less and use less electricity than going one size up in pumps.
He has it wired to 220V with each leg wired to one pump. Both pumps have to be on before the heat can be turned on. The pump on the left has an input port for WVO. The pump on the right has an input port for the methoxide. Biodiesel and Glycerin are drained out of the center pipe with third pump used to pump the biodiesel into a wash tank. The processor also includes a baffle in the TEE where the two lines come back together and return back through the upper element hole. He has also included a baffle inside the TEE where the two lines join just over the element hole and a nozzle mounted inside the tank to provide for "in the tank" mixing. The original drain line has been used as the processor's vent.