A longer flue provides more draft. Therefore more air is needed. Drill more holes into the round plate to provide air where the fire is...hence, fueling the fire. I also use a stainless steel pot which heats up red hot and adds to burning used engine oil. My hole-less pot to chamber pipe glows red hot. At the end of the day after 20 liters I have a slightly tarry/soot/ash left in the bottom of the pot. Hope this helps.
My comment comes from my experience with piston engine aircraft, where the fuel/air mixture is controlled manually by the pilot, often by reference to an exhaust gas temperature (EGT) gauge. As the pilot begins to lean the mixture, the EGT rises. But if the pilot continues leaning, the temperature will peak and then begin to fall. Relating this to an oil burner, it is my supposition that the cleanest - i.e., the least smoky - burn occurs at the hottest temperature, which is achieved by introducing just the right amount of air. If too much air is introduced, the efficiency of the burn will be reduced, the temperature will fall, and smoke will result. If I'm correct, and your smoke problem is caused by a too-lean mixture, then it stands to reason that reducing air or increasing fuel will increase the temperature and reduce smoking.
In answer to your incomplete combustion when you introduce more air; what may well be happening is that you have increased the velocity of the gases going through the stove, therefore full combustion is taking place further into the system. It may help if you use a shallower pan and if you haven’t done so, add a baffle plate in the tank which may slow the gases down and lead to better combustion at the secondary stage.
You need to add holes in either the top plate of the fire chamber or in the top edges of the bowl of the lowest bowl chamber where the fire is too much oxygen at the top not enough in the bottom it needs to be able to pull air into the lower section
If one were to make a unit like this and fabricate and air control at the bottom of the burner, and one in the burn tube to see how the fire reacts would be the way to find the optimum temp and clean burn. I noticed on several videos that they drill holes all over and find ways to get it o burn hotter and cleaner, but there doesn't seem to be any control of the intake air during the burn process to see what actually works the best. Maybe installing another tube around the upright burn tube with an air control on it will show you better results. And fabricating an air control somewhere on the bottom will also show better results, so you can go from there to make the final product without all the guess work.
Hi these waste oil heaters burn more cleanly with negative air pressure. The more noise they make struggling for air the cleaner it will burn. As the temperature rises you can calm that noise down by opening up the air a little. It seem you have to many gaps above the pot where air can come in without to much control therefore it will smoke. If you put to many holes in the second burning tube it stops the draw of the fire. But it looks kinda right. Check my website on www.dripfedwasteoilheating.com just might help or I can help you through the site. Before you do any adjusting add more flue first to give it more draw. Cheers Hamish.
Did you ever figured it out? Is there an " Update " Video? So far during testing mine / making mine... Funny thing is... The " LESS " Air, the better the burns... I don't know if you have that figured that one out?
Make the small holes in your pipe bigger than little holes make bakker make more let it burn from their not below make your stream very thin a constant not just a drip as thin as the number one pencil lead or number two very thin and you’ll see a major difference in the heat in the burn and no smoke check out Jerry DIY Ireland he’s got some amazing burners and if you have a problem he can help you let me know how it goes thanks Tony Shaw
Dude, stop waving the camera like its a litht saber !!! Nice stove. I built something and also getting some smoke sometimes. Will experiment some more.
When you give it more air your draft moves fuel fumes up past were oxygen is readily available so as your getting incomplete combustion when draft is slower you create less fumes that have time to completely combust before moving up to oxygen restricted exhust area
