Air Supply for an Oil-fired Furnace?

I don't see how the air supply is a problem, once you have a burner and a flue the air will get sucked in through a hole at the bottom by convection (or fan assistance).

Is your problem vapourisation of the fuel to make it burn?

Or is this some vast furnace that needs blowers to supply the air?

Del

Hello, I am not sure what type of oil you are planning to burn but I have recently built a burner to burn used motor oil in my shop furnace and a small glass furnace. You can go to yahoo newsgroup altfuelfurnace and find a wealth of knowledge about converting standard fuel oil furnace burners to burn either waste veg. oil or waste motor oil. You would probably be surprised to see how many people are burning used vegetable oil in the home heating systems. Most of the burner designs are based on buying a new heater block, retention head and a siphon type nozzle that uses a small amount of compressed air to deliver and atomize the oil although you will find some people who use a pressure system as well. All of these burners have a fan that delivers combustion air along with the compressed ( 5-10 psi) atomizing siphoning air to the burner. I have found that you need very little combustion air if any to make the oil burn when using the siphon type nozzle. The oil atomizes and burns very well with very little smoke with the siphon nozzle as long as it is pre heated via the burner nozzle block. The burner nozzle block is usually made from aluminum with a cartridge or band type heater, a J thermocouple and a temp controller. You do need to filter the oil before using it and I built a small pump skid with hydraulic oil filters to do this. I pump my oil through from a storage tank through the filters into a smaller level controlled day tank before it goes to the burner. With propane running in the neighborhood of 2.60 per gallon here it is casing people to look for alternative fuel sources.

pipewelder

wonderful pipewelder n thanks for your message. well am trying to use waste oil coz of its availability.since iam using crucible for this matter what is eating up my mind is how to design an oil pump know that air pressure needed is quite small in order that the oil gives me a spatial or jet before it burns as air circulates freely around the crucible.

Hello, The waste vegetable oil is getting pretty hard to find around here. large processing companies have started buying it up from the restaurants and of course the price has started climbing. Now waste motor oil is another thing entirely but there are some state rules about gathering it and burning it that one may need to check on according to what area they live in. I only take oil that is brought to me by friends when they change their motor oil and might have a few gallons. What is amazing is how well the modified oil burners burn this oil when they are tuned correctly. There is hardly any smoke at all and it is a very whitish color indicating a good atomization and fairly complete burn. When using the compressed air siphon nozzle it is harder to find a low enough pressure to keep the flame from "blowing out" than anything else. What I am saying is it takes very little air to do this. Also when my burner is running I can completely shut off the combustion air from the fan and see very little difference in the flame. I work at a paper mill and we burn waste motor oil to start our boilers and to run two lime kilns. When you really look at it there is not allot of difference in these burners compared to the smaller siphon burners other than they utilize steam to atomize and heat the oil before burning and rely on a fan to deliver large amounts of combustion air. I am not sure what type of furnace you are using but with my glass crucible furnace I do not want the flames directly on the crucible so I am looking into a new design that has a bag wall between the flame and the crucible. Once the furnace gets up to 2250 degrees F the atomization is not near as important because at this temperature the oil will burn just about any way you could pour it into it. Well just a couple of observations I wanted to share on this subject.

pipewelder

First you need to decide the quantity of oil to be fired and accordingly you should calculate the excess air required for the complete cobustion. The air fuel setting can be done after the installation of burner system.

"Stoichiometry". Ask Wikipedia about it.