diesel fired melting furnace

[8ob]

I was reading up on flame temperatures, LPG burning with an orange flame = 1000 c blue flame = 1980 c. Quite a difference in both temp and probably the niffs coming off the top, some of this home grown stuff looks like it could do with tuning on the air/fuel ratio front. Or does it make no difference in a furnace

Bob

 

[julianf]

The vid above is essentially the same design as the one in my video - just chuck the oil in, it gets hot, and burns!

I don't think you necisarily need the bulbous bit on the burner though. The burner will be firing into (in a refractory, more than a forge) a glowing hot chamber anyway, so, as I see it, the pre chamber is just an added complication. I guess it would start combustion that much sooner, but, when you're running on fuel that is as cheap, and as high output, really, what does it matter? As demonstrated by my very very basic build in my own video, it gets hot...

"Oil burner" on YouTube (Australian chap) also uses this simple setup with massive output.

They're not controllable without residual heat though (the chap in the vid above talks about adding mass to retain heat) but, not that I've got that far, I'm hoping that the dense caatable hot face of my build will retain plenty of heat for these stability concerns.

 

[jordhandson]

Jord, thanks for the pictures!

My latest foundry is also based on a beer keg (pumice chimney liner section surrounded by vermiculite and cement mix).

Can you give any details of your burner nozzle construction? You appear to be using two nozzles - an LPG one situated behind the one for waste oil?

Covalent I will dig out some more pics and do a separate posting on the the burner build, the first nozzle I made was just oil and air I ad to light it with a blowlamp then on the other nozzle I incorporated a gas line in just for starting before switching to the oil.

Cheers

 

[jordhandson]

I was reading up on flame temperatures, LPG burning with an orange flame = 1000 c blue flame = 1980 c. Quite a difference in both temp and probably the niffs coming off the top, some of this home grown stuff looks like it could do with tuning on the air/fuel ratio front. Or does it make no difference in a furnace

Bob

The pic are of the first firing of the burner I agree you have to play with the air to get a real blue flame. I think I have video some where with a much better burn. I will see if i can find it.

 

[Kayos]

Blue flame is complete combustion, yellow is incomplete and therefore produces more carbon monoxide, with a decent chimney and ventilation it should be no worse than a ho.e made log burner

 

[8ob]

Blue flame is complete combustion, yellow is incomplete and therefore produces more carbon monoxide, with a decent chimney and ventilation it should be no worse than a ho.e made log burner

I suppose if you are burning waste oil its not as important but if you are paying for the smelters fuel it would want to be running efficiently. Also wonder if the sooty burning flames contaminate the molten material with carbon

Bob

 

[julianf]

I'm not sure as I've even seen a kerosene burner burn blue. Maybe wick kerosene burners right at the base of the flame, but that's about it. Pressure jet burners (ie standard oil central heating burners) have always been yellow, I'm sure.

I've come across the comment before - has anyone seen an oil burner burn blue (I mean in the same way as you would expect a gas burner to be blue)?

 

[julianf]

I suppose if you are burning waste oil its not as important but if you are paying for the smelters fuel it would want to be running efficiently. Also wonder if the sooty burning flames contaminate the molten material with carbon

Bob

Bob, so far as I'm aware, its actually entirely the opposite - people run the furnaces at slightly incomplete combustion, so as to reduce oxidation of the stock.

 

[daleyd]

Most industrial burners run with an excess air if anything (depends on application of course). On complex systems there is usually some algorithm in the control system to increase the air before the fuel valve is demanded to open, and the reverse when closing off, ie the fuel closed first then the air.

 

[gaz1]

blue flame waste oil

 

[carbon]

I know we all like "cheap" on here but is the burner end of things worth messing/cheaping out on when you can buy a working pressure jet burner for peanuts. All ready to run on heating oil or red diesel for £80 or less. I am not sure how one would wire round the safety gear on these like the flue stats etc but I am sure its doable. Just sayin

https://www.ebay.co.uk/itm/Electro-Oil-Sterling-40-ST108-Oil-boiler-burner-Central-Heating/352686963150?_trkparms=aid=1110001&algo=SPLICE.SIM&ao=1&asc=20131231084308&meid=df1e3f67dc60404f9705a6c391540a55&pid=100010&rk=1&rkt=12&sd=183840835519&itm=352686963150&_trksid=p2047675.c100010.m2109

With these burners the control unit usually switches the ignition off after the burner is burning as the ignition transformers don't have a 100% duty cycle which isn't a problem in a heater/boiler as starts - stops aren't that frequent. I'm not sure of the wiring connections on these but believe its possible to wire some of them to continue running the fan when the fuel is turned off as I've used similar control units on some industrial space heaters but cant remember what model control unit was fitted

 

[jordhandson]

Have made quite a few of these burners sold a number and given a few to friends they do work well.
This was the first one i ended up making


When it was really freezing and the oil was thick I added a coield round the end to sort of pre-heat the oil but i found if i warmed the oil first it did not need the pre-heater.


I added the gauge to monitor the air pressure, likes whats been said increasing the air makes for a cleaner or what i call a leaner flame.

need some better weather now to melt my little bit of ally all ready collected



The nozzle were made from some old steel rod all the tapped threads are 1/4 bsp as got plenty of fitting the nozzle tip is .8 mig tip


Jord

 

[slim_boy_fat]

@jordhandson So, is the right-hand tube end in this pic closed off?

 

[jordhandson]

@jordhandson So, is the right-hand tube end in this pic closed off?

Hi No both ends of the tube are open



Cheers

 

[gaz1]

no its used as extra air through the tube some have used a vortex manipulator to try and get a better mix on flame

 

[gaz1]

i like tilt for safety

 

[julianf]

View attachment 182617

Jord

Jord, I'm wondering what youre casting, and how you're doing it?

 

[julianf]

...and is that swarf in the bin? Looks granulated?


I've never got my swarf to properly melt. Just forms a lump of honeycomb dross / alloy.

I wondered about wrapping it and plunging it, but it does not seem worth the bother really, so I've not tried. But if you have an easy method, I'd like to know!

 

[slim_boy_fat]

no its used as extra air through the tube some have used a vortex manipulator to try and get a better mix on flame

In that build, from reading on here, wouldn't his burner entry to the keg have been better offset to one side to create a 'swirl' of the flame/heat?

 

[captain-destructo]

Thats interesting, so in theory you could build in a thermostat and temperature control the furnace ( cut fuel) as long as you had a device to run the fan on for a while to stop the burner/gubbins cooking.

I am paying attention here because I have a huge pile of ali wheels to melt down and am thinking of building a big smelting pot

Bob

I had a weigh in yesterday EMR
old rolled ali 39p per kg
ali wheels 70p per kg

might be worth checking they don't knock the price down because you have melted them into ingots