Waste Oil Boiler

[DRJensen]

Has anyone had experience with building or purchasing a waste oil boiler? I see one from Murphy's Machines but cannot find on the web any information from anyone who has bought the plans and built one. I would like to buy or build one and burn waste ATF  for domestic hot water and heating (hot water coil in HVAC duct) in the winter time. Thanks for looking and adding any comments.

Dave

[Dualfuel]

Dave, I would check on biodieselinfopop, that guy posts on that forum all the time. DualFuel

[glort]

I have been testing a gas hot water heater with the burner removed and a waste oil burner substituted.

I have been using a Passive type burner which works fine although a bit inefficient. It takes about 3L of oil to Boil 90L of water. To get it to boiling which you don't need in a domestic situation, takes about 2.5 hours.
The ideal setup for this would be to have a burner with a sufficient oil capacity so you light it and it has enough oil to heat the water to the temp you want and run out of fuel. That way you could light it, walk away and not have to tend to it any further till you wanted more hot water.  Alternately you could set up a feed system and just add enough oil to achieve the same thing. For a constant heating setup you would want something like a remote fuel bowl with a float system like a carburettor that fed the oil as needed and maintained the fuel level depending on demand.

I'm about to test the heater with a forced air burner which I believe will work better. The heater came with a " spreader" that goes down the flue but I cannot use with the passive burner because it carbons up and blocks everything. The forced air burner can run totally clean so apart from the ability to produce much more heat, I think the use of the spreader as was originally designed will put more heat in the water from every litre of oil. For reliable Fuel control I plan on using a dosing pump so the burner gets a set amount of fuel at all times according to the heat required.

My initial idea with this was to use it for home heating as against just water heating.  I plan on using a circulator pump and sending the water into the house and using a small car radiator and fan to transfer the heat.  I'll build a box to house it and the fan speed controls in to make it look nice although I also have an old indoor unit from an aircon I could try pumping the water through. The high side pipes are pretty small though so I don't know if sufficient water will go though to get enough heat. The coil would be highly efficient though.

I was also given an old gas fired central heating unit. I have pulled that apart and am going to try replacing the gas burner with an oil burner. I just need to make up a manifold for the burner to direct the output through the Heat exchanger pipes. The blower is already there as it the fan speed control so all that would be needed is  vents to direct the warm air in the house.  The burner will need controls and safety shutdowns on this design which the gas burner has but I doubt if the controller will be able to be adapted.

If you are thinking of adding a copper coil for heat transfer you might be better off looking at a radiator, even the heater unit from a vehicle. Most of the ones I have seen have 3/4" in and outlets and are very dense coils and fins and would transfer a lot of heat.  I know copper must be cheap in the US but it seems a very inefficient way of transferring heat. 

[oiler]

I bought one like this about two years ago and I have never seen a burner as efficient and clean burning as it...
http://www.greenoil.ch/manual_englisch_burner.pdf

I'm burning WWO, gearoil and hydraulic oil with it and I clean it once a year.

[ToddT]

I've researched them for a few years and like you, I'm leaning toward Murphy's. I've been cautioned against drip type and even Babington type heaters in that you need to be nearby all the time to monitor the operation. Oils heat up and the viscosity changes. Different types of waste oil will have different viscosities. I want a system that will adapt. It looks like Murphy's design will adapt to variables.

I've followed him on the infopop biodiesel forum for years. He seems like a good guy and a solid fabricator. I trust his design. I have bought his plans. Just waiting on some bigger paychecks to buy a welder and plasma cutter from Eastwood so I can get to fabricating. In the meantime, I'm accumulating enough obtanium to make it happen.

My plan is to use various sources of heat: solar, waste oil, cogen from the radiator and/or exhaust of a generator. Use what is available with not only Plan B but Plan C as well.