WMO Kiln.

[greasemonkey]

This is still being built. I wanted something to gently melt solid oil, but this is not it. It is way to hot.

Fan assisted burner.



An old oil central heating burner, somewhat modifyed. The pump has been removed, and the lockout disabled. The oil jet and pipework has been removed, and the blowpipe is welded onto the shroud of the burner.



This is an experiment, just to see what I was playing with. Initially, I ran the fuel pipe down the middle of the blow pipe, but it just wasn't vapourising the fuel well enough. So I just ran the fuel pipe along the top of the blow pipe, and let it drip into the air stream. Above, the flame was controllable, and was staying in by itself.



And this is the stage it is at now. Success of a sorts, I can really see how this could get hot enough to melt non ferrous metals.
I've been starting the burn with a paintcan,  with some super dry hardwood in it, lit be a fire lighter.
It takes about 10 minutes to get it going, if you get it right. Its a lot easyer to light in the drum, than on the flat. The paintcan has a slot in the bottom, and some holes drilled in it,and I position it so the oil stream shoots onto the burning embers inside. After less than two minutes, I pull the paintcan out.

To start with, there was oil burning on the floor of the drum, then it started to catch, and the drum was about half full with swirling smokey flame. Then it started getting more and more fierce, and after a little while the drum was full of a really steady swirling flame, going all the way back around the the blow pipe. Then it stepped up another gear, and the heat was incredible.

Now I want to put some concrete around the inside of the drum, and narrow the chamber down, and make a lid. I'll also make a more permanent job of things, its all lashed together at the moment.

I'll update this thread as I get on with the job.

Sadly I don't have a photo of it burning, I'll try and remember the camera when I light it again.

[Tony]

That is very cool (well, hot, I suppose!)

I'd love to experiment more with burning glyc, perhaps this summer

[greasemonkey]

Hmm, glyc, never thought of that. If or when I get things running a bit better, I'll try and get my hands on some, and see what happens. I would imagine it would burn it, the heat is phenomenal when it gets going.

Now I've actually proved to myself that the concept works, i can concentrate on building it nice and solid.

[Julian]

Looking good, but for heaven's sake don't line it with concrete, the stuff will explode if it gets too hot.

I made a small iron melting furnace some years ago and you could buy small quantities of refractory material, I think the generic name was "grog", quite cheaply.  It seemed to be clay with some type of pea shingle mixed in.  You lined the casing and then lit a small fire, increasing the temperature over quite a long period to dry it out slowly.

Once dry it set like concrete but withstood temperatures of around 1100°C!

[julianf]

Im really keen on seeing how you progress with this.

I was looking for crucibles on ebay only a few days ago.  I would like to melt down all the aluminium offcuts / swarf etc i generate from work, and cast blocks from it, for re-machining.  Big chunks of aluminium are not cheap to buy, and i have loads of material that's otherwise scrap, as its just in the wrong shape!

Has your camera got a video function?

[julianf]

Can you let us know more detail of the burner too -

Am i right in thinking that you are only using it as a fan? 

And how is the WMO added (pumped or what?) and whats the WMO pipe terminated like?

I read about that american kit a bit - that seems to work by blowing high pressure air over a vertical nozzle, to create a syphon setup.

[Julian]

Im really keen on seeing how you progress with this.

I was looking for crucibles on ebay only a few days ago.  I would like to melt down all the aluminium offcuts / swarf etc i generate from work, and cast blocks from it, for re-machining.  Big chunks of aluminium are not cheap to buy, and i have loads of material that's otherwise scrap, as its just in the wrong shape!

Has your camera got a video function?

Julian, if you want a quick play, I did my first, small aluminium casting using a bean can and the log fire in the front room.

Then have a look at "Foundrywor​k for the Amateur" and "The Backyard Foundry" both by B. Terry Aspin.

I used to get my supplies from F. L. Hunt and Co., but they don't seem to be around any more.  I'm sure there are other suppliers though.

[Head Womble]

Looking good, but for heaven's sake don't line it with concrete, the stuff will explode if it gets too hot.

I made a small iron melting furnace some years ago and you could buy small quantities of refractory material, I think the generic name was "grog", quite cheaply.  It seemed to be clay with some type of pea shingle mixed in.  You lined the casing and then lit a small fire, increasing the temperature over quite a long period to dry it out slowly.

Once dry it set like concrete but withstood temperatures of around 1100°C!

As a side note this type of refractory material can be radioactive, a lowish MB count but radioactive all the same.

[Julian]

Looking good, but for heaven's sake don't line it with concrete, the stuff will explode if it gets too hot.

I made a small iron melting furnace some years ago and you could buy small quantities of refractory material, I think the generic name was "grog", quite cheaply.  It seemed to be clay with some type of pea shingle mixed in.  You lined the casing and then lit a small fire, increasing the temperature over quite a long period to dry it out slowly.

Once dry it set like concrete but withstood temperatures of around 1100°C!

As a side note this type of refractory material can be radioactive, a lowish MB count but radioactive all the same.

Ah, that would explain why I've grown a third ear.

[julianf]

Im really keen on seeing how you progress with this.

I was looking for crucibles on ebay only a few days ago.  I would like to melt down all the aluminium offcuts / swarf etc i generate from work, and cast blocks from it, for re-machining.  Big chunks of aluminium are not cheap to buy, and i have loads of material that's otherwise scrap, as its just in the wrong shape!

Has your camera got a video function?

Julian, if you want a quick play, I did my first, small aluminium casting using a bean can and the log fire in the front room.

Then have a look at "Foundrywor​k for the Amateur" and "The Backyard Foundry" both by B. Terry Aspin.

I used to get my supplies from F. L. Hunt and Co., but they don't seem to be around any more.  I'm sure there are other suppliers though.

Ive just had a look at the two books on amazon.

My concern is that they seem to be more on casting (ie molds etc), rather than the bit before that?

As all i want to to is make lumps, im wondering if i would be dissapointed with the content of the books?

[Julian]

You are probably right, but pattern and mould making are very much more tricky that cobbling together a furnace.

From memory this was for a coke fueled furnace, but I'm sure it would do for other fuels.  You may need to adapt the air inlet  ...


Having tested your grog with a handy Geiger counter, get a couple of 20ltr tin drums (I had trouble finding them at the time ... no so much of a problem now!).

Cut the top off one drum and discard.  Place a layer of grog in the bottom and ram home to ensure there are no air gaps leaving a 50mm thick layer with a smooth finish.

Cut a hole in the side of the tin, flush with the top of the layer of grog.  The hole should suit whatever forced air pipe you intend to use.  Cut another hole about 50mm from the top on the opposite side to be your outlet.  I used a piece of cast iron down pipe. This should point up at about 45°.

Cut the top off the second can, about 50mm thick and save.  Cut the bottom off and slit longitudinally.  Overlap the cut ends to reduce the diameter and fit into the first tin.  Adjust the diameter to give a 50mm gap all round.  Cut some wood to be the diameter of the inner, reduced tin.

Fit a lump of wood through the air hole in the outer tin so it touches the inner.  This acts as a core which will be removed later.  Fit the flue pipe into its hole and support at the correct angle.  This will stay in place.

Start packing grog between the tins to form a 50mm thick wall.  Remember to ram it down to preclude air.  Use the wood to prevent the inner tin from collapsing (probably could use plywood circles with a centre hole to aid removal).  Fill to the top and set aside.

Take the lid from the second tin and half way down the sides make 4 equally spaced holes.  Push two steel rods about 6mm dia through the holes to form a cross with about 20mm protruding each side.  Pack the lid with grog, again making sure no air is trapped.

Leave the whole lot to air dry in a warmish place for a week or so then start a small fire and slowly increase its size and temperature to thouroughly dry the furnace.  Don't rush the drying or it will crack.

Let us know how you get on!

[Tony]

Fire cement is just clay and cement, very heat resistant, though I don't think you can make big things with it, it sure seals blocks together.

[Head Womble]

You can get refractory material that is made for casting, you do a wet mix and pour it in,
vibrate to draw air bubbles to the surface.
This will set over time but still needs heating, raising the temperature slowly.
The important part is to hold it at 100° for a few hrs until the steam slows down,
before slowly increasing to to normal operating temp.

I spent many years working at an incinerator so have some experience with refractory.

[Head Womble]

Looking good, but for heaven's sake don't line it with concrete, the stuff will explode if it gets too hot.

I made a small iron melting furnace some years ago and you could buy small quantities of refractory material, I think the generic name was "grog", quite cheaply.  It seemed to be clay with some type of pea shingle mixed in.  You lined the casing and then lit a small fire, increasing the temperature over quite a long period to dry it out slowly.

Once dry it set like concrete but withstood temperatures of around 1100°C!

As a side note this type of refractory material can be radioactive, a lowish MB count but radioactive all the same.

Ah, that would explain why I've grown a third ear.

Three ears and still can't hear the wife.

[Julian]

You can get refractory material that is made for casting, you do a wet mix and pour it in,
vibrate to draw air bubbles to the surface.
This will set over time but still needs heating, raising the temperature slowly.
The important part is to hold it at 100° for a few hrs until the steam slows down,
before slowly increasing to to normal operating temp.

I spent many years working at an incinerator so have some experience with refractory.

Is that the stuff they call slip used in lost wax casting?

One day I'll need to make another furnace ... do you know of any suppliers prepaired to supply small quantities?