Introduction: Forge / Furnace Propane Jet Burner
Building a Propane burner for a forge or furnace.
I wanted to revisit my aluminum foundry, previously I had it running on charcoal which turned out to be messy and expensive and in the UK its hard to get charcoal in the winter.
I decided I needed to build a propane burner as propane is available all year round from multiple places and can even be delivered. Its clean and fairly cheap once you have paid for the cylinder.
I have looked around at various designs and i have settled on the
EZ Burner (Easy Burner) designed by Ron Reil, originally designed for a forge it would be suitable for a furnace. The EZ burner is an adaptation of Ron Reil's original burner, the main difference is the end is not flared which would have to be done by heating the end up and hammering it on an anvil. This would require a forge, which I don't have, I could have flared it using an improvised forge using bricks and charcoal but I figured i would just try the EZ Burner and see if it was powerful enough and it seems to be.
Check out this video of it working.
my plan for this burner is to put it in a new Furnace so I can melt aluminum and copper and cast it.
Step 1: Parts and Tools
1 1/2" to 3/4" malleable steel reducer
3/4" 300mm malleable steel pipe threaded at both ends, though you only need the thread at one end.
1" malleable steel pipe, I ended up with one that was threaded at both ends
1 1/2" short threaded malleable steel pipe, I ended up with one threaded at both ends.
8mm x 200mm malleable steel pipe
1mm drill bit
Hack saw or other steel saw, my mitre saw can cut steel so I used that
Propane gas bottle
High pressure propane regulator
Gloves and goggles for protection
Step 2: Design and Theory
The design of the original burner you can see in the image I have attached, on Ron Reils website he doesn't show pictures but describes the EZ burner. He also goes through how the burner works.
The idea is that by having a reducer at one end with a pipe between and then opening up again at the other end it creates a vacuum, known as the venturi effect, which draws air in from the back so it burns the gas properly.
you can read more on the venturi effect on this wiki page
what we are aiming for is a nice blue flame, a yellow flames says the fuel is not all being burned and its not burning efficiently. A blue flame says its all being burnt and as such is much hotter than a yellow flame.
you can get a better hotter flame by flaring the end of the pipe, but for what I need its not needed.
Step 3: Cutting the Pipes
All we need to do here is cut the ends off a couple of pieces as we don't need the threads on one end.
the 1" pipe I cut the end off, this will form the end nozzle of the burner.
and I cut a piece off the end of the 1 1/2" pipe, but in this case I need the short piece, I will use this later in the reducer to hold the gas pipe in place.
The 8mm pipe I bought was 400mm long so I had to chop that in half.
Step 4: Perparing the Gas Pipe and Reducer
I welded one end of the 8mm pipe shut so that gas wont escape, you could use an end cap. A lot of people use a brass pipe for their gas feed.
I then made a mark on the 8mm pipe which marks the width of the reducer from the welded end, then half way along I drilled a 1mm hole. When you drill in to metal your bit can slip so its best to use a center punch and a hammer to put a little dent where you want the hole, this will help to stop the bit from slipping. be careful with the 1mm drill bits they are very brittle and be snapped very easily.
I used a bench grinder to put ridges on one end of the 8mm pipe so that when I clamp the gas line on it will hold and not pop off with pressure.
I then needed a 8mm hole on either side of the reducer so the gas feed pipe can go through, but I need it far enough down so that I have some of the inside thread I can use to put some pipe in to clamp the gas feed in place.
Fortunately the manufacturers have put a mold seam through the middle which you can use to work out where the middle is on each side. I put the reducer on some paper/card and put marks where the seam lines where, then rotated the reducer and used those marks to mark the reducer. From those lines I just made a mark further down on each side. Center Punched and drilled the holes.
It pays to use some files on the holes and the cut ends of the pipes so you don't cut your hands.
Now its just a case of putting it all together, the welded end of the 8mm pipe should be flush with one hole, then screw in the 1 1/2" off cut of pipe by hand just tight enough to hold the pipe in place.
Step 5: Assemble and Test
so now its just a case of putting it all together and testing it.
screw the reducer on to one end of the 3/4" pipe and slide the 1" pipe over the end, this will be really tight, i made the mistake of giving it a couple of taps with the hammer, so now its stuck on there. Opps. what you could do is put a couple of slots in the 3/4" pipe and drill a hole in the 1" pipe for a screw to hold it in place. For me I am not too worried about it being stuck it does what it needs to do so i wont be removing it.
something that is important is the position of the hole in that 8mm pipe, loosen off the pipe holding it in place, and position the hole so its facing down the length of the burner roughly centered to start with. later on we reposition it for better flow.
hook the gas up to the feed and at a low pressure turn on the gas and using a long kitchen lighter light up the burner. You should have a yellow flame, slowly turn up the gas until it starts to jet and burn blue. It may blow its self out which is ok this can be because of too much pressure so you can back the gas off. if you can't get a blue flame loosen the feed and turn it slightly so the hole is pointing up/down towards the wall of the burner, only a little though, this will help to mix the gas with the air and you should be able to achieve a nice blue flame.
a blue flame is hotter and it means that all the gas is being burned and not wasted.
here is a video of the burner working
In conclusion It would have been better to flare the nozzle as I would end up with a hotter flame as the vacuum would be greater and thus pull in more air and burn much more efficiently but for my purposes this will be fine. prehaps at a later stage I will flare the end, or build a new one with a flared end.