home made outdoor waste oil boiler experiment

[gardrail]

Managed to get some fittings welded into the holes that were cut in the top and sides.

Top bung - 3/4" with 1/4" bushing for pressure testing



Water outlets to circulate the water 1" bungs welded in-place. They are ground flush to allow the center bits to slide in for welding



Tractor supply primer painted on there to prevent rusting. I have a feeling this may cause some problems in the future - but hey, it's the first that may not work anyways

 

[chim]

I'm no en-gineer but this seems like a project that shouldn't be done in a home built manner. Just my $.02

I'm not an engineer either (nor did I catch a few Z's at the Holiday Inn Express) but am not all that concerned about safety. Gardrail did say it will be outside and will have a relief valve. My worry is the current design is short on surface area for heat transfer and cross-sectional area for exhaust flow. I would expect to see a bundle of tubes.

I do applaud the effort and it does look like an interesting undertaking. I have a bud who heats his shop with an old oil gun in a 14"Ø pipe. He uses regular heating oil in his though.

 

[Raspy]

As Chim said, the surface area seems really limited. Before you weld it closed, maybe put a baffle of some design to make the water pass back and forth over the tubes and be more turbulent.

At least you probably won't have any condensing problems in the exhaust system and it will be fun to see how it works. Then you can make the next generation and address any weakness.

BE SURE TO USE A PRESSURE RELIEF. A standard hydronic relief is set a 30 PSI, or are you planning on running the system at higher pressure?

I like projects like this.

 

[vwnotrunning]

Be sure to put more than enough relief valve(s)! Configure the exhaust tubes in a manner that will allow for easy cleanout / brushing. Waste oil gases and low temperatures will soot up quickly and will require frequent cleaning unless you get the burner tuned just right.

 

[gardrail]

Thanks for the suggestions!

I stopped by the local plumbing supply shop to pick up the couplers (lowes and home depot only had the cast iron ones) and priced out the residential pressure relief valve (30psi) - that's why I went with a 3/4" connector on the top so the valve can go there.

The idea of cleaning out the exhaust tubes that go through the boiler itself is in the back of my mind as I build this out. I'm envisioning some kinda flange that I can attach the chimney to that can be easily removed so that a wire brush can be run through the tubes every now and again. Until I get this thing dialed in, I expect to find soot everywhere.

On a side note - I bet a pretty sweet forge could be built using those siphon nozzles from Patriot Supply. With enough air/O2, and the 1 gallon per hour nozzle I bet most things could be rendered to ash or a molten puddle of ooze.

 

[stingray1]

I'm not an engineer either (nor did I catch a few Z's at the Holiday Inn Express) but am not all that concerned about safety. Gardrail did say it will be outside and will have a relief valve. My worry is the current design is short on surface area for heat transfer and cross-sectional area for exhaust flow. I would expect to see a bundle of tubes.

I do applaud the effort and it does look like an interesting undertaking. I have a bud who heats his shop with an old oil gun in a 14"Ø pipe. He uses regular heating oil in his though.

I agree,you need a lot more tubing to make this work.

 

[gardrail]

hot gasses go through the black iron pipe - not water

I don't trust my welds that much

 

[chim]

hot gasses go through the black iron pipe - not water

............................................

Yep, understood that. Our company installs - not designs -various heat exchangers. Some are steam to water, others are water to water. Two types we encounter regularly are plate type and tube type. All the tube type heat exchangers I've seen have bundles of tubes that are very close together. One big deal with any heat exchanger is having sufficient surface area for the heat to be "exchanged".

Google "tube type heat exchanger" and you'll see what I mean.

 

[gardrail]

Yep, understood that. Our company installs - not designs -various heat exchangers. Some are steam to water, others are water to water. Two types we encounter regularly are plate type and tube type. All the tube type heat exchangers I've seen have bundles of tubes that are very close together. One big deal with any heat exchanger is having sufficient surface area for the heat to be "exchanged".

Google "tube type heat exchanger" and you'll see what I mean.

Ah! I totally see what ya mean! Unfortunately I think I'm a bit too far in the design of the guts on this one. The next one I'll probably use 3/4" EMT instead of 1" black iron so that more surface area is available. I also got some ideas for baffles from a few of the images I saw - i think a 2.0 version will need to be built after I finish this one.

It's not a total loss as I'm picking up some welding skills, and if all of the welds are water tight - some confidence in my own abilities.

As far as surface area for this model, it looks like with the pipes i'll have ~ 497 square inches of surface area on the pipes, and an additional 30 square inches on the bottom plate

 

[Bigfoot62]

I'm impressed. At least you're trying. I've thought about a waste oil heater for years, but never did anything about it.

As far as your "engineering" goes, I wouldn't worry about it. I think it has to work. Maybe not the most efficient design, but we're talking waste oil. It's not like you're paying $4/gallon for it.
Think about a water heater in an RV. It is an air-to-water heat exchanger, and it has a single burner tube in a 6 gallon tank.