I want to build a small smudge pot fueled by a tank of wvo. I want it to heat an exchanger to heat water for radiant heat for a ski hut.
materals

4 inch cast iron cap (ci)
2 inch copper pipe (cc)
4 ci cap
4 by 2 wye
4 by 2 bell
pipe
2 in ci wye
2 in copper 90
swing joint
pipe



I have seen one burning wvo, it has the intensity of a blow torch.

Anybody using a smudge pot?

thanks
smudge pot vented

pot

This message has been edited. Last edited by: HogWash,

I built this in the summer to dewater my WVO.. Its a flash evaporator.. Around 50,000 btu's or so.. It heats 60 degF waste veg oil to around 300 degF at about .6 GPM.. It would heat water to 190 allot faster..

Its maintenance free until it rains.. I need to put a rain hood on it..
You can use either an electric pump or gravity feed it.. The two 55 gallon drums are just the tank for dewatering.. The gas to liquid heat exchanger is a simple copper coil. About 20 feet of 1/2 inch tube.. Its not very efficient and was just a proof of concept project for a new burner design.. I needed a way to dewater a couple hundred gallons a day of wvo anyhow..

A copper coil in a fire tube is not the best way to make a heat exchanger.. It works but there are much more efficient designs.

I have one of those smudge pots. We call them Salamanders. They come up on ebay now and again. ALways cost quite a bit becuase of thier rarity. I paid 80 quid (150 dollars) just to get one to play with. They roar when burning right. That side tube acts like some kind of preheat turbo like effect. And the little dimpled holes spread the air around but accelerate it in because they are small.

Never knew they were called smudge pots. Thanks.

bio in a smudge pot

http://www.selah.k12.wa.us/SOAR/SciProj2006/DerekL.html

Looking at the links to the old photos at top two designs are used.

One is strait the other is re-vented to create a vortex.

I have got oil to burn in a 4 inch ci cap with a 4 by 2 ci wye and a 4 by 2 bell on top. I have to stop the fire to clean the tar and stop the excesive smoking.

My internet and phone are down and i have limited acces throught the library so no, I can`t. Mine is the vented type. The vent comes from just above the inverted cone section of stack whiscgh is also the section with all the air holes. That is about half the total hight.

It will throw off frightenibng amonts of heat if you stirr up a pool of burning byproduct with a bit of copper pipe. It remains to be seen what unbufrnt goo or ash residue may eventually remain from byproduct burning.

quote:

It remains to be seen what unbufrnt goo or ash residue may eventually remain from byproduct burning.

Hard cake if in a pot type burner. I do it all the time now that it is colder. I use large coffee tins cut down to a lip of 10cm or so, fill them with the glyc, add a little recovered methanol on top as a primer and spark it. I have two of them and it gets the reactor warmish in about an hour, but I can see daylight under the door as well

Yes, I found a dry crust forming over the surface towards the end of burn and a thick tarlike goo underneath it.

I assume methanol and biodiesel burn off first and leave glycerine and whatever behind.

I found a lump of this goo would melt when added to a shallow pool of burning fuel so it should burn if kept hot enough.

the dry crust inhibits vaporisation and burning though.

I extended the stack to twice it's normal hight which helped some.

I am toying with the idea of joining the three air holes in an arc to provide for at least twice the air in a controlled manner.

Experiments with hanging the damper lid off its hole suggests more air than normal may be better with this fuel.

completely open with a four inch hole is perhaps too much as the whole thing starts to glow red.

I have been explained that a smudge pot has a damper on the stack to change the burning of the fire to make it smoke.
It can be tuned to burn so hot and fast that it will whistle through the vents.

Mine has a damper where the stack meets the bowl but it is springloaded and has only two positions, open and closed. A catch holds it open and ir you bang the other side of the catch you can close the damper up quick, I assume to put it out.

I did this to a burning pot that was near the end and it had filled with soft black foam when I came back to it. must have burned some from air coming down the side pipe.

mixing in UMO with byproduct makes the BP burn away more cleanly. The UMO stays lit better and there is no goo at the end just ash cake. Scrapes off. Burns hotter and faster too. But very sensitive to air intake and a devil of constant fiddling to keep the smoke down. Not good. Anyway, intuition notwithstanding, John Galt is right; UMO is suprisingly toxic when burnt.

Bio burns really well.

Hot and bright. No smoke. Easy to control.

See what, if any, residue is left at some point.

here are some pics from ebay.

ed_1.jpg (23 Kb, 68 downloads) pot

and

I have been buring oil in cast iron fitting plumbed together. It works great with little smoke after cleaning the tar off the ci.

23_1.jpg (22 Kb, 74 downloads) smudge opot

After some use I have realised the principles of operation behind this deceptively simple design.

The side pipe does not recirculate smoke back into the combustion chamber. Flames and smoke are sucked up the side pipe and blast down into the uprising flames and smoke in the flue. This acts as a second flame source and they keep each other lit and ensure the after burner works right.

The sloping top of the fuel chamber and the taper of the perforated afterburner, act as a venturi design. This sucks air through the perforations and promotes complete combustion. It also provides the suction on the side pipe to pull flames and smoke up and create a `pilot light` that keeps it all burning reliably. When running right the emissions are negligible and it can be vented inside a workshop or garage. This is very efficient for heat usage.

The flaw in the design is that when shutting it down smoke will come up through the side pipe and out the afterburner perforations. What it needs is a second butterfly valve on the side pipe to seal off the fuel chamber completely.