Oil Burners for Casting Furnace.

[impalabazz]

G'day you blokes,

Well I got my 25kg. bucket of Petrobond Friday last after the help I received from you fellows in the "Wanted Petrobond" thread.:2tsup:

Now it's time to start building the furnace. I have a bag of castable refractory which I bought last year and intend using a 25 litre paint tin for the outer and a piece of 6" or similar pipe or flue for the inner diameter.

Originally I intended using LPG as the fuel but I reckon Waste Engine Oil, Vege Oil or even Diesel will be much cheaper alternative. What do you guys think and have any of you used or using this method for heating ?.

I have some basic Oil Burners plans (downloaded from the net) for a Babington type burner. Seems simple enough with gravity feed Oil and compressed Air. Both of which I have in abundance.

I will be casting mostly Aluminium, but no doubt will try bronze at some stage.

Look forward to your responces........Barry.

[watson]

G'day Barry,
Seems you're heading in the right direction.
Cupla years ago, LPG was probably the go...no more.
There is another thread here on Babington burners with every link you're ever likely to require. Don't forget the very small hole required to get them to work efficiently.
Lots of luck

[scooter]

Be interested in your progress, Barry, read a couple of the links Noel mentioned the other night & ruminated on making a workshop heater based on the same techniques.

Keep us posted. :)


Cheers................Sean

[watson]

G'day Sean & Barry,
Here are some more links for oil burners.
http://journeytoforever.org/biofuel_library/ethanol_motherearth/me4.html
http://pateri.com/Foundry/Burners.html
http://www.motherearthnews.com/library/1970_September_October/Cheap_Heat
http://www.angelfire.com/pro2/jason_foundry/oilburner.html
There is another Mother Eearth News article, where the guy uses a Gas Cylinder as the heat radiator for a workshop, with an oil burner up the spout.
I have "gifs "of the burner, but not the entire article

[Schtoo]

I use kerosene, and will probably switch to waste oil in the very near future. Not because kero is expensive, but the burner I use isn't exactly user friendly. A waste oil unit isn't all that user friendly either, but at least it has scope to be a little easier to work with and potential for more BTU/h.

Since you have compressed air, give the babington a try. I am not keen on them since I don't have compressed air, and if I did I'd be running a pressurized system identical to what I have now with adjustable pressure and stick with kerosene.

There's nothing special about them, main things are a good mix of air and fuel, along with ability to adjust the balance and to have a burner with good reliability and flame stability.

(I'll be blunt here, I don't like the babingtons very much because it seems to be an awful lot of jerking around and there are not all that many out there and being sprouted as being a good thing. That worries me a little, even though I fully understand how they work and why. Don't let me stop you though since I know they do work, I just don't like them all that much.)

I plan to use a small can lined with insulation and a thin hotface of castable, inlet and outlet as a kinda pre-furnace to heat up the oil and air and make it get going. If it doesn't work out as planned, I'll stick with kero till I work it out and the small can will become a small melting/heat treat furnace.

[Mick C.]

Schtoo, and others i guess...

I see you dont have compressed air... but, all the fiddleing about with a preheat etc to have enough heat inside to be able to get the oil to start combustion is just a huge pain. The way i did mine was to use kero as a start and then change to oil with the aid of a twin needle valve (made for the job) to mix in the oil and to back off the kero seemlessly and also giving the ability to adjust how much heat you want to generate. In the 44gal drum that the furnace is built into, i could have it running on straight oil in less than 2 mins... Just a thought or different way of doing it that others might like to try... :)

[Schtoo]

Let me put it this way...

For the cost of a single needle valve I could buy a compressor and use it to run the burner, and have it do only that.

I don't have have any needle valves, so I design accordingly.

So, how does your burner work specifically?

[Mick C.]

Schtoo i adree with you about not being able to aford to buy a needle valve, let alone a twin!!! Mine cost me about $9.00 for brass fittings and the rest was a scrap block of Aluminium and some M6 stainless rod and about 4hrs of my time...

My furnace has 2 pressurised pots, one for the kero and the main pot for the oil, used auto trans fluid in my case, both of these have about 25 psi of air to them. Each pot goes to the twin needle valve, and the outlet into a jet mounted inside a piece of 65mm pipe, with a reducer down to about 22mm, at the end of the pipe. The jet is located (depth wise) maybe 10mm back from the front of the reducer ( this gives a high speed air stream to help with the atomisation of the kero or oil as it enters the furnace). The piece of 65mm pipe has the exhaust of an industrial vacume feeding into it for the forced air supply, and there is a hole in the side of the 65mm pipe with a simple slide collar to be able to bleed off the unwanted extra air, for when the furnace is being started or running at a lower heat level.

I hope all of that is a lil clearer than mud! :)

(Somewhere i think i have some pics if anyone is interested, but they might take a lil finding.)

[impalabazz]

G'day All,

Thanks for your replies. I'll have a look at those websites for suitable designs. Discovered a couple of likely suspects on a Casting Web Ring. Will report back with some thoughts once I have a clearer picture of which way I'll go.

In the meantime I'll start construction of the furnace. Seems as though I'll need a 2" minimum inlet pipe for whatever burner I use. I'm using ideas sourced from Casting publications I have to hand as well as what I've found on the net.

Thanks again...........Barry.

[scooter]

(Somewhere i think i have some pics if anyone is interested, but they might take a lil finding.)


Yep, interested :)

[Mick C.]

Here's a few pics, sorry bout all the dirt etc but its been a few years since its been used!

[Mick C.]

And the last few... If anyone has any questions please feel free to ask!

[scooter]

Thanks Mick, it's an involved looking contraption :D

[Mick C.]

It's a lot easier to use than i guess it looks :) But then again aren't allll projects out of the shed supposed to be a lil over the top or excessive or over engineered in some way :wink:

[Harry72]

EPA just love oil burners...

[impalabazz]

G'day Mick C,
Thanks for the pics.:2tsup: Initially I thought that the 65mm inlet pipe would be overkill, but I see that you are using a 12 gallon drum for the furnace. I assumed that a 20-25 litre drum was being used. With your description of operation plus the photo's it's pretty clear how it works.

Got any old photo's of it in action ?.

Cheers.........Barry.

[Mick C.]

Hi Barry,

The drum is actually an old 44 gal drum, yup a whole 200 liters :D

The actual entry to the furnace is a piece of 6" pipe lined with clay etc and reduced to maybe 3" i think a beer bottle actually fits there as a form :rolleyes: The position of the fuel/air delivery pipe when being used is the same as in the pics. With it in this position it also draws in secondary air from outside, in with the main air stream.

The 44 gal drum has one row of fire bricks on their edge as a liner and is backfilled with clay. The floor and roof and chimney are the same but a lil thicker. At the first heat up the unit was also lined or coated on the inside with glass to help with heat reflection. This was done by crushing what was a full window of glass from an old mini and literally throwing it into the furnace through the chimney with it running and lots of care. The improvement could be seen almost imediatly at the flame and heat distribution inside the furnace cause by the reflective surface.

The comment before about the EPA is prolly more than just a lil right, BUT, with the ability to finely adjust the fuel and air deivery it is easy to adjust how rich or lean the furnace is running and it can be run with absolutely no smoke from the exhaust!!! The only smoke from the unit is at the initial start up, first 30 secs maybe or when someone gets a lil eager to make a lot of heat or noise and gets a lil carried away with the fuel and air and gets a lil smoke from it being rich and likes the look of the flames 3 or so feet high out the top of it :D

I do have a few pics of it in action with a pot with about 6.5Kg of aluminium just out of it about to be poured into a sand mold. But these are on film somewhere and may be a lil harder to find and transfer, but i'll look none the less :)

[forge]

Some links on oil/gas burners,foundry techniques etc.Have not found a clear set of how- to plans for an oil burner:?

http://www.backyardmetalcasting.com/index.html
http://home.iprimus.com.au/cmckeown/foundry.htm
http://l.webring.com/hub?ring=hobbyfoundry&list&page=0
Regards,

[Schtoo]

Harry, the EPA do love waste oil burners, since if they produce heat that is used for a legitimate purpose, then it's considered recycling which they will typically endorse whole-heartedly.

I sure as heck wouldn't want a poor running burner since it wastes fuel, isn't very hot, produces large gobs of smoke and soot and is generally a waste of time.

Mick, very interesting. Does the thing run a blower of some sort, or is it strictly a fuel pressure thing?

Looks like something I could most certainly rig up. :D

[Harry72]

We got rid of all the oil burners at work, the furnace/gas train engineer's(and CSIRO) could not make them comply to emission regulations.
Not to mention the safety factor of unburnt fuel in an combustion chamber, oil doesn't dissipate like gaseous/light distillate fuels while purging the chamber.
I have 1st hand experience at what can happen... blowback is not fun.
Just because there's no smoke doesn't mean there's no emissions, otherwise car's wouldn't be polluting would they?

[AwDeOh]

Hey guys,

Just stumbled across this thread and thought 'Hmm!'. I work at the Mount Isa Copper Smelter as a converter operator, so I thought if you guys want to know anything that I might be able to find out from work or might already know, feel free to ask. Not sure how much help I can be with hobby casting, but I might know a few things. Got a bit of experience with converters, anode furnaces, casting etc.

Cheers,

Mitch

[Mick C.]

Schtoo,

Yes the unit runs a blower. Am useing the exhaust from a small industrial vacume cleaner that is connected to the back end of the 65mm pipe with a short piece of Skeet tubing. The vacume is useally bolted to the bracket thats sticking out to the right of the large oil pot in the 2nd pic, may be a lil hard to see, it's covering up a lil piece of the tappet cover thats laying in the background.

[jmk89]

Schtoo,

.. in the 2nd pic, may be a lil hard to see, it's covering up a lil piece of the tappet cover thats laying in the background.

:worthless: You bet it's hard to see - where are the pictures?

[Mick C.]

The 2nd pic would happen to be the one on the previous page as part of the 8 or so pics i provided the other day :rolleyes:

[jmk89]

The 2nd pic would happen to be the one on the previous page as part of the 8 or so pics i provided the other day :rolleyes:
:booboo:

Sorry Mick, I got confused about which pictures were being referred to.

[impalabazz]

G'day you blokes.

I've started construction of the furnace and have enclosed some pics. I have used basic plans from one of the casting books I have to hand.....although not right to hand as I type this. :B .....it's out in the shed which is closed up for the night.

I have used a 25 litre paint tin with an inlet and outlet pipe of 52mm O.D. Internal size of chamber is approx 160mm diameter. I used a large coffee can with a thin sheet of polycarbonate wrapped arround it for the internal former. A bag of Moral Cast refractory was used. I will need another bag to complete the job.:doh:

Bottom layer of refactory is approximately 80mm thick and has a 26mm (approx.) hole through the bottom for molten material escape. This was cast last night and was still a bit soft this morning. I didn't have any mix instructions so I added enough water to make a regular type pouring cement.

Bottom 52mm dia. inlet pipe sits just above this bottom layer at approx. 110mm on centreline and is aimed at the left side of the internal chamber. This will create a clockwise swirling action.

Exhaust is on the left side of the chamber and positioned approximately 70mm down (on centre line) from the top edge.

Both pipes have been plugged for casting purposes. Once this current pour has all set I'll be able to remove (hopefully) central former. Then punch out the tape on the ends of the pipes and open out the passages which "should" only have minimal refactory in the way.....well that's the theory ??:roll: .

Once another bag of refactory is sourced, probably next week, I'll finish off the top 30-40mm and cast a 3" lid with sight hole in the top.

That's about it for the moment. Pretty simple so far.

Catch ya' later............Barry.

[Schtoo]

Quick question/suggestions.

Is the castable you are using insulating, or just good at taking the heat? If it's not insulating (read as light!), then I would suggest putting some insulating material (kaowool) between the outer skin and inner hotface or leaving a gap so some kind of insulator (perlite) can be poured in after it has all set up.

I did this on the sides of mine, but still made the hot face too thick. It takes a bit of heating up, but it's not too bad. When the inside is orange/red, the outside is warm enough to touch barehanded. If the thing was solid, then the thing would take an hour or more to heat up and would cause no end of problems.

If that castable is alumina based (99% sure it is) then pouring is probably a little too thin. Make sure it dries thoroughly and slowly heat the first time to make sure all the moisture is out.

Problem is this stuff goes from too stiff to too sloppy with a drop or two of water.


I also made my exhaust out the top so long bits of scrap can be shoved down the hole into the pot. Worth thinking about.

What you got so far looks pretty slick to me though. :D

[watson]

G'day Barry,
I used Darley Refractory Densecrete for my foundry, and their mixing instructions were 1:1 with water, by weight.

[jmk89]

Here's an article about (http://www.rexmill.com/) a guy in the US who made his casting furnace in a galvanised garbage tin (click on Heat Treating in the menu on the right hand side of the page).

The site has quite a lot of interesting stuff on woodwork (inc sharpening), planes and wood-related metalwork. Some of the links are interesting too (has anyone got GBP 3,200 space to buy a plane!!!!):oo: :oo: .

[impalabazz]

G'day,

Thanks for the input's.

Schtoo, the Moral Cast refactory I'm using has a type of wool in it as well as perlite, or at least I think it's perlite. Considering that the 25Kg bag of Moral Cast is the same size as a regular 40Kg bag of cement I'm guessing it must have the other ingredients in it, otherwise it would weigh similar to a bag of cement ?. I may have to put some insulation material arround the outside in any case as it's only 2"-3" thick on the outside at the thickest.

I found a "mix your own" castable refactory mix on one of the links (Lionels Lab I think) provided on this forum. Might try that one out in a Coffee Can furnace if I can find some fireclay.

Yes, you are right, it doesn't take much more water to go from a dough consistancy to slop !. I found that out in the last pour.

When I pour the lid (when I get the next bag of refactory) I will put a 2 " diameter hole in the middle for sighting and adding material to the crucible. I reckon I'll put a sliding lid or something over the hole.

The casting books all recommend caution when heating the furnace for the first couple of times to "burn off" moisture.

Thanks for your interest and I'll keep you all posted with progress.

Cheers...........Barry.

[Schtoo]

Ok, you got alumina castable cement, which is the same as what I got.

The 'other ingredients' are filler, probably not insulation. Best suggestion is find out who made it (or where you bought it) and ask them if it's insulating. The bags of castable I got are not insulating, are the same size as a 40kg bag and weigh 25kg a pop. Thickness of this stuff, 2" is plenty adequate.

BTW, congrats on getting the right stuff. Tough at all temperatures and resists attack by fluxes. You will realize that's good when you start doing things, trust me.

(Like knowing when you throw in a bunch of agressive flux and know that it's not going to hurt your furnace!)

The castable needs little in the way of care thankfully. Make sure it's fully cured, then stick it outside a stuff in some wood and set it off. Haved a barbeque or something. Just make sure the moisture is out of it. It doesn't need to vitrify like caly based refractories, ala Lionel's mix.

Might be a good idea to make up a plinth block. Just a small slab of castable to sit on the ground so you can rest hot things on it without hurting anything. You can also stick them in the furnace if you need to lift some things up for heating. I have a couple, and they are plenty useful.


When I made my furnace, I thought I thought of everything, but I missed a few things. Just letting you know what they were so yours works better than mine. ;)

Oh yeah, the lid on mine swing aside lifted by a foot pedal with a cam on the end. Just push it down, swing it away. Found it somewhere online, and it was the best thing I ever did. Add in a pot that has lifting lugs and a pouring eye, a lifter and a hook and I can pour ally without getting anywhere near hot things. Far enough away that I can do it without gloves. I do wear gloves at all times, but I don't need to. Just another safety thing. :)

And pics when yer done please. :D

[impalabazz]

I've ordered another bag of refactory. The company I bought the first bag from some 2-3 years ago, (yes this furnace and casting idea has been going arround for that long.....and longer) Thermal Ceramics in Adelaide don't handle the Moral Cast brand anymore. But they gave me the 1300 contact number.

It's made by Shinagawa in NSW I beleive, pick it up tomorrow. It's rated to 1600 C.. I reckon it's cheaper this time than last @ $66.00 plus per bag. This will give me plenty to finish off plus extra for a couple of plinth blocks and other bits and pieces I'm not aware of right now. Sounds like I stumbled onto the right gear first off. That makes a change !.:U

What about crucibles ?. I intended making a couple out of steel tube for melting ally to start with. Weld in a bottom and some lugs and fashion a spout. I've got some 4" diameter pipe, approx. 2mm wall, would that suffice ?.

Sounds like a good idea on the lid. I'll have to put on the thinking cap soon and do something similar. Also a trolley to move it all arround is on the cards as I don't have a designated area as yet for it to permanently live.

As far as the burner is concerned I haven't made any progress there other than finding a couple of designs on the net.

Cheers............Barry.

[Schtoo]

2mm should be fine. I know a lot of folks use soup cans, and I think they are nuts, well, were nuts...

One of the castings I plan to do needs a big bit of ally, plus a lot of the things I need to break down are pretty wide.

I have lots of baby formula tins about, so one of them might have to see melting duty for a run or two. No more than that because it will die pretty quckly, plus I doubt it will hold enough metal at that temp before it dumps it's guts.

Thicker stuff buys more time till it needs replacing is all. My main pot is a piece of 100mm ID, 120mm OD, 250mm tall iron pipe with a 6mm base jammed in and welded. That thing will outlast me easily but it isn't quite big enough for the 7kg casting I want to make.

I can also get some stainless cooking pots that are wider but much shorter that will just hold the ally, but it's going to be close. Still holding out for some bigger pipe with about 2mm wall.

You will find that with a large furnace ID (mine is 250mm) and a much smaller pot OD (120mm for me) you use a lot of heat that doesn't get to do very much.

I want to get a 150-180mm OD pot, 3mm wall, and about the same high, maybe a little taller. The efficiency should go up a bit and make it less tedious to melt stuff. As it is, mine takes about 25-35 minutes from stone cold to @1500cc of molten ally. That's too long for the burner I have and in an insulated furnace. Problem is that thick crucible and it's small diameter.

(And stupid me was worried about burning it through too quickly, when after several heats it shows nothing from the effort...)

[impalabazz]

G'day All.

I hope everybody has had a good Anzac Day. :)

Schtoo, I have the official specs for the Shiracast 165 castable refactory that has replaced the Moral Cast. It is non-insulating as you thought and rated at 1650 C recommended operating temp. up to a maximum of 1850 C. The agent indicated you could go higher but don't expect much life out of the furnace.

The refactory contains high purity chamotte and low iron calcium aluminate cement. 12 month shelf life.

Thanks for the input on the fabricated crucibles.

Update on furnace construction.

I have now cast the last 3" to top up to the top of the drum. Tomorrow or Friday I will cast the lid as well as remove the former (friday) in the furnace and inspect. I'll take some more pics and post them here then.

It'll be getting close to fire-up time in a week or so, so I better "get a wriggle on" and make an oil burner !.:roll:

Thanks for your help............Barry.

[impalabazz]

G'day all,

Well time flys when you're having fun ?. After getting some RL issues sorted I managed to get the first "modified" babington burner running......in a fashion.:~

I say the "first" burner because number 2 WILL have some design changes.

Got some tuning issues to sort out, but it produces a good blue flame. :roll: Don't have any pic's yet but I'll post a couple when I fire it up next in a couple of days.

Then I'll wack it into the furnace for its first firing.:o

Cheers..........Barry.

[watson]

Well done Barry.....would love to see the pics.

[impalabazz]

G'day All,
Here a couple of pics from a "burn" performed earlier tonight. Unfortunately the flame doesn't show up with the flash, but you'll get the idea. I'll take a couple more pics on the weekend without the flash when I get some oil feed issues sorted.

So this is what I've done so far. The burner tube is a piece of 45mm dia. x 150mm long exhaust tube I had in the scrap bin. Nice slide fit in the 2" tube I have in the furnace. I blanked off one end with a large flat washer. The Babington type oil feed is a 1/8" BSP brass 'T' fitting with a brass cap that I drilled .046" thou.. It became this size as it was the smallest I had and I couldn't buy the recommended #80 drill down south of Adelaide.

The cap screws onto the 'T' from inside the burner tube and locates the assembly. A groove was cut with a fine round file from the edge of this endcap to the centre to provide a "guide" for the oil to run down and over the Air outlet orifice. The hole was drilled in the lathe and on the inside of the cap I used a no.2 centre drill to put a small taper on the hole for the purposes of a needle valve seat.

Then to reduce the size of the Air outlet orifice I made a needle valve from a piece of 6mm MS rod machined to 5.3 mm OD and bored and threaded to suit a 4mm cap screws I had on hand. I "guesstimated" the taper require for the needvalve tip. The cap screw fits into a threaded cap which in turn fits to a bush and screws onto the other end of the brass 'T'. Now all I do is adjust the capscrew for air flow out the orifice. Works a treat.

Finally a 1/8" BSP to Ryco Air fitting was added to the setup. Delivery Air pressure seems to be quite low but I haven't checked it for a definative answer, but seems to be about 14-20psi. when it's burning nice.

The oil delivery has proven to be an issue. I have read and now beleive that the delivery rate is critical for consistant performance as "flame-out" is easy to achieve. Tonight I could only achieve maybe a minute of operation at "blue flame" before it became unstable and blow itself out.

Other problems are that the Quick connect Airline fitting gets way too hot. I'll have to fit a fixed pipe and fitting further away from the burner. The needle control also needs an extended operation handle simply to keep your fingers away from the burner.:o

With all that aside, I'm quite happy with the outcome so far.

Pic 1. Shows basic experimental setup. 3/16" copper pipe coupled to rubber vacuum line. T fitting with valve for some oil delivery control. Oil reservoir on top.

Pic 2.Ignition with paper dipped in 15w40 oil. Slowly turn the needle valve and increase flame.

Pic 3.Burning nicely now. If you look close you can see a very sligh yellow/red flame against the black bench.

Pic 4. Burning hotter now, blue flame, roaring nicely........seconds later, flame out with LOTS of smoke.:~

That's it for now. I'll have more after the weekend I hope.

Cheers.............Barry.

[silentC]

Just had a thought. Our gas cooktop has jets with varying sized holes. They're simply a brass nipple that screws into the top of the burner base. I wonder if it would be feasible to use one of them with the correct sized hole if people have a problem drilling holes that small?

[Mick C.]

Hi,

I dont really know whats inside your burner unit, but with the one i have built, it needed a hole size for your "jet" thats pretty close to what your useing! Another fellow told me at the time that it was supposed to be about the #80 size some .018", but i couldnt get enough oil through it for it to work, and after looking at his setup, it turned out to be lots closer to the .040" size, and this is keeping in mind that i have about 25psi of air on top of my oil... My thinking is the viscosity of the oil you are useing will probably be the most determining factor to jet size, anhd perhaps pressure depending on your setup. Hope that helps and made sence :)

[impalabazz]

G'day Mick C and Silent C,

Yeah, I had similar thoughts with the viscosity of oil etc.. I plan on using "old" oil from cars and trucks after running it through a filter. The ability to adjust the flow as well as pressure will be critical. I was using the 15w40 diesel oil 'cause I had it on hand. We use it in our Tool Truck and I have about 20L of old diesel oil on hand. I will persevere with the modified Babington Burner for the time being.

My next experiment will be with a modified "Kero" cleaning gun. I reckon a syphon feed like on a spraygun maybe more reliable than the current gravity feed setup. The tip will be the problem as they are not designed to cope with heat. Maybe a spraygun could be used also ?........I'll have to investigate that one too !......we have a "number" in stock.:;

As far as using gas burner jets, I'll have a look at one. The reason why I used the needle valve idea was to restrict the outlet size if it needed, as I only had .046" thou. drill on hand, and being a larger hole, would make cleaning easier. Personally I reckon a #80 hole will clog up over time with caked on carbon deposits etc..

Thanks for your suggestions. :U. I will report back here when I have more results.

Cheers............Barry.

[WrogerWroger]

Fuel Injectionshun for your furnace...


Your burners.. the spraying / atomisation bits should not be getting hot.

SUMP oils are FULL of nasties.... if they can be used, look up a way to commecially clean them up for burner use... see how they do it and if it's easy enough, use it other wise don't use raw sump oil.

A kero cleaning gun would be ideal for the right sized furnace.. (define huge) but they tend to flow far to much air for the given volume of fuel, also the atomisation is rather coarse.

BUT it's the PRINCIPLE of using a small amount of compressed air, coming through a small hole, into a bigger hole, and expanding at an included angle of 20* that leaves a partial vacuum behind it, that is where you hook your suction feed point into.


Set a simple needle jet into the feed line and then control your air pressure and fuel delivery and you will eventually get the mixture and flame size right.

Start with small holes and work your way up.

A simple gravity fed feed tank to the fuel suction reserviour is the easy way to feed the unit, a pump fed one, from the LOWER level is better.

It may pay to start your furnace on petrol (low air pressure and fuel rate = small flame and be fast to light it) and then switch over to the heavier oils when the furnace becomes hot enough for the heavier fuels to autoignite from the radiant heat in the furnace.

Spray guns.. they generally flow at a fuel delivery rate that is TOO low for a stable combustion process.

[silentC]

Start with small holes and work your way up.
That's why I thought the gas jets might be good because they come in graduated sizes.

I thought part of the beauty of the babington design was that you didn't need to filter out impurities because they just drop off the atomiser and into the sump below. As long as the return doesn't get clogged, all should be fine.

[impalabazz]

"I thought part of the beauty of the babington design was that you didn't need to filter out impurities because they just drop off the atomiser and into the sump below. As long as the return doesn't get clogged, all should be fine."

Yes, you're right. The oil flow is external over the jet in the babington design. The babington uses a ball shape burner with the jet at one end and the oil flows over the top in a thin film. Most of the oil flows off the burner, "unburnt" and is collect underneath. Then pumped back up to the reservoir.

The "modified" babington design I'm using, uses a "U" shaped groove cut into the burner face so that oil is guided over the jet. Excess oil drips off. My theory was to supply only a small amount and burn it all, no excess or only a small amount while warming up.

In my case where my theory has fallen over is I don't have enough oil flow.:no: Increasing the flow almost eliminates the flame out problems I'm having. Now it's just a matter (I hope) of modifing the burner so as to collect the unused oil out the bottom.

I tried the kero gun and oil will not "pick up", so I'm guessing that the vacuum applied is too low for heavy viscousity fluids.

Cheers..........Barry.