|
|
||
|
Project: Dewatering and Filter System for Cold Weather In my last article on filtering and dewatering oil, I was experimenting with steel 55 gallon drums for heating the WVO over an extended period of time to remove suspended water and help with settling. Heating the oil also helped with filtering to 5 microns. After one summer of successful barrel heating, I found that I was not able to get the temperature up high enough to heat the oil enough to dewater or hot filter through filter socks. I do not have a heated garage so after a day of leaving the heating element on and suspended in the steel 55 gallon drum of oil, it was only slightly warm in portions of the barrel nearest to the level of the heating element. In the pictures from the previous article, you can see where I used foil bubble insulation to wrap the steel drum to keep the heat in. This helped slightly but the oil still did not heat completely through (top to bottom) after a good 8 hours of leaving the heating element on and suspended in the oil. After researching biodiesel and the appleseed reactor for my own edification, I realized that the homemade biodiesel reactor would serve as a fully insulated filtering and dewatering vessel for WVO. I called several plumbing services in my local community and had one respond that they would call me when a 50 gallon or larger electric hot water heater is brought in for disposal. About 3 weeks later, I rode over to Fitzgerald & Sons Plumbing and picked up the donor vessel below.
After a thorough cleaning on the outside, I began removing the old connecting copper pipes and started rinsing the interior with a garden hose. Lots of rusty sediment flowed from the bottom of the hot water heater for about an hour of running water from the top inlet pipe into the heater. After reading the instructions for preparing a hot water heater for conversion to an Appleseed reactor, I began disassembling the top of the vessel to get to the anode rod plug. I had to dig through foam insulation, but I finally found what looked like a large bolt screwed into the top of the hot water heater. I removed the bolt and about 4 inches of the remains of the anode rod! I now understood that the rusty sediment that was flowing out of the bottom of the vessel was the remains of the anode rod. The threaded hole at the top of the vessel looked like a good spot to vent the system so I used teflon tape and a 3/4 inch cast iron nipple long enough to protrude from the top of the hot water heater and screwed it in place. A little aerosol can of Great Stuff filled in the missing foam insulation I had dug out of the top to get to the anode rod. After spraying it in the top, I replaced the cover and screwed it into place.
Now the real fun began. Time to design the plumbing system to fill and drain WVO from the Filtering and Dewatering system. Most of the plumbing parts were purchased from Lowes hardware. All parts were cast iron except for a few gray plastic hose barbs. In addition to the cast iron from Lowes, I purchased several 3/4 inch brass ball valves from Harbor Freight for controlling the direction and path of the WVO through the system. If you time it right, you can catch them on sale for around US$2.00. Electrical parts include two electric water pumps for filling up the system and pumping the dewatered WVO from the vessel through a sock filter and into a storage drum. In addition, various switches, timers and wire were purchased to control operation of the pumps and heating element in the hot water heater.
According to the Appleseed Reactor instructions, if there are two heating elements, the top unit should be disabled and bypassed along with any thermostat specific to the top element. My tank had a bung for the top element but it was plugged with a bolt and no extra thermostat. This is going to make the wiring of the dewatering filter system much easier!
Here is a picture of the WVO dewatering and filter system with all plumbing in place. All that is left is the wiring and final connection to the collection drum and filtration drums.
Step 1: Heating and dewatering the oil! Once the collected WVO is placed in the settling drum, I set the ball valves in the position to accept dirty, wet WVO into the dewatering and filtration vessel and turn on the pump. Oil is sucked from the settling drum, through the water pump, up the plastic sight tube and into the hot water heater. The ball valve at the base of the hot water heater is closed to keep the oil from draining out the bottom while the vessel is filling. The breather barb at the top of the water heater allows for displaced air to escape allowing for more WVO to enter the dewatering and filtering vessel. Once the vessel is full, the ball valve at the top is closed and the heating element is turned on using the timer switch wired to the element. The timer is set to 8 hours and will automatically shut off when complete. After shutoff, the oil is cooled by letting it sit for a couple of hours to allow the water and sediment to fall to the bottom of the vessel. Before reheating the oil for filtration, the water and sediment are drained from the bottom of the tank using the plastic spigot on the bottom. The waste is drained into a 5 gallon bucket and can be either discarded in one of the cubies or can be boiled to test for water content. The latter helps me to judge the amount of water that is emulsed in the oil that I am collecting. Once the waste is drained from the bottom of the vessel, the spigot is closed and the heating element is turned back on for approximately 4 hours or until the full 50 gallons of oil is at approximately 130 degrees. (thermostat is set to this value during rewiring of the hot water heater)
Step 2: Filtering the dewatered oil!
In my initial summer filtration system using barrel pumps and drums, I used a two stage filtration system that first, filtered the oil to 10 microns and then, in the secondary filtration, pushes the oil through a 1 micron sock filter. I found that not only did the 1 micron socks clog quickly, but the oil was not leaving any sediment in the fuel filters mounted on my veggie vehicles after thousands of miles. My analysis was that the second stage of filtration was unnecessary for the current application as long as I reduced the primary filtration level from 10 microns to 5. The method described above should work well for both summer and winter dewatering and filtering in most climates without modification. This is an ongoing research project so I will post new information as I finish the buildout of the dewatering and filtering system by wiring it up and finishing the connections to the settling and storage drums. I am also considering locating a sock filter housing to completely enclose the system for safety reasons. Veggie Ranger
|
||
|
|
||
