LP gas configuration to melt gold

[saadat68]

Thank you
I forget take image from furnace but I uploaded an image before http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=25677&p=273316#p273316
I think my crucible is #8 and I want to melt 500 to 1000 gram silver in one pour
I have adjustable high pressure regulator with gas output : 0-43 psi
It doesn't have degree bit I think I set it on 10 to 20 psi
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I afraid remove orifice because I think it is unsafe. isn't it ? :shock: ( For example flame go back to the tank )
Here we have 2 models orifice. one model is for LPG gas and another is for natural gas. I bought LPG orifice but it was small than 1 mm. this was my mistake. (I didn't know #60 is 1 mm)
So I changed orifice with natural gas orifice that it is 1 mm. I get a better and stronger flame now.

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I tested this orifice with all of my burners. These are the best flames that I got

1-1/4 inch - air force burner :
http://uupload.ir/files/2hef_img_20170902_215536.jpg

Video :
http://iranbm.com/saadat68.mp4
Is this neutral ? If yes I can go build a new one with 1 inch pipe
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Venturi propane burner:
http://uupload.ir/files/76z7_img_20170902_210351.jpg
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Burner bought from shop (I change it's orifice too ):
Can I melt with this burner?
http://img31.114pifa.com/3315/7eAn5hrCV_1417975693.jpg

Is this neutral ?
http://uupload.ir/files/fomr_img_20170901_193025.jpg

 

[Lightspeed]

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=40&t=25610

research this site, there are plenty of links: http://www.hybridburners.com/index.html

I use one of these, Cheap on ebay: http://stores.ebay.com.au/Thermal-Art-Design?_trksid=p2047675.l2563

homepage: http://www.thermalartdesign.com/
Don't underestimate this burner it may be small but it is excellent, with the correct size chamber and refractory it will achieve what you want for your purpose

When you have done enough research you can draw your own conclusions, there are many functional ways to achieve what you want to. There is plenty of rubbish on youtube and a few that are actually good.

A few pics of mine just after the ceramic layer was applied to the ceramic fibre.







Play safe Saadat68

 

[saadat68]

Thanks Lightspeed
I made furnace before just need a burner

Today I test air force burner with 3/4 inch pipe
http://uupload.ir/files/hwvs_img_20170903_182338.jpg

I uploaded 4 images from 4 burner. Which one is neutral ?
I think the last one is the best. Right ?
Just it's flame is small.

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If I make an orifice with 3 mm hole and add to my burner, Is it safe?
Is there a chance to flame back to the tank for example when bower turns off? :shock:

 

[saadat68]

http://uupload.ir/files/hwvs_img_20170903_182338.jpg

My flame is like :
http://cdn.smokingmeatforums.com/1/10/667x500px-10dc2330_furnace_burner2.JPG
http://gaijinto.blogspot.com/2011/02/propane-burners-old-and-new.html

So it works and it is neutral. right?
If yes, maybe a one inch burner with 3 mm orifice will be better

 

[Lightspeed]

This first link is the the directive I have used to help me with setting my flame on my burner. However I do not use a used a forced air burner, I would imagine that due to the available oxygen from the blower it may be somewhat more of a challenge to get away from an oxidising flame, ideally you need adjustable air output on the blower, and a venturi on the burner to adjust at least some of the available oxygen mixing with the LPG/Propane, without this I don't see how you can manipulate or cause any effect on the Burners flame, other than by gas pressure adjustment at the regulator relative to air pressure.

Flame Settings: http://northstarglass.com/users-manual/flame-settings/

http://ronreil.abana.org/richtolean.jpg

http://www.hybridburners.com/new-vertouri.html

https://www.youtube.com/watch?v=75gJV3pcbME

A 3mm orifice, Wow you are going to consume a propane bottle in no time with that, its huge!! You will probably suffer from freezing issues with that amount of gas flow through the valves and regulator.
Study the above links, you must read what is contained and study your burners flame, the flame you have shown looks like its oxidising to me, due to the amount of fuel from the orifice it may not be.

 

[saadat68]

Thanks Lightspeed
If I use 3 mm orifice I will use a low pressure regulator too to prevent freezing tank

Here's how i would do it. First use a 1 in pipe. Length doesn't matter. The longer the pipe the more mixing it has this way. Do away with the orifice. I don't think your getting enough gas from what i'm seeing. That's why you can only turn the air up so far before a flame out! The regulator and hose will deliver it, but your restriction is the orifice size. When i use to run and build aluminum sweat furnaces i have actually just drilled a hole in the side of the blower casing and put in a hose barb and piped the gas straight into the furnace. That was a trauma fix to keep from shutting down. It took $ 3,800 and 36 hours to bring that furnace up to operating temperature from a cold start not to mention you don't just shut a machine like that down cold turkey. You have to have a controlled temp drop or your refractory will sprawl all to hell and that's a $100,00 problem.

After you do away with the orifice it gets pretty simple.

Hi
I want to test again without orifice. Is it safe ?
Is there a chance to flame back to the tank for example when bower turns off?
Is 3 or 2 mm orifice better and safer? (Because I can not find 1/8 or 1/4 inch pipe)
Thanks

 

[Lightspeed]

I think you should get away from the blown burner for a first burner project, this thread seems to be going in circles, the info already posted is tried, tested and accurate, the web links and pics from Butcher and info from Palladium are also accurate. A blown burner is not necessary for your melt size, eg: look at the burner flame on the T/rex for proof if you scrap the blower and simply run a venturi burner with what you have already experimented with you would have found success. You do not even need more than 1 1/4 inch, 1 inch is more than adequate. You are trying to build a Saturn 5 Rocket and its simply not going to be economical to run for small melts, my 3/4 venturi burner easily melts 1kg charges at 20psi, I can wind it up to 160,000 BTU but I simply don't need to.

Make things easy on yourself and put a gas needle valve, or gas ball valve inline with the fuel feed so you can play with varying amounts of fuel mix and air, not just a straight feed from a regulator.

Your Burner tube needs a bell on the end at the least or a flare of some description.

I do not have experience running open pipe for a fuel orifice, sounds like Palladium has, though, I cannot advise on its use from a safety aspect, myself, my own mind tells me to be wary. As already stated an arrestor is not needed unless you are mixing an oxidiser and a fuel source combined, don't take that as a go ahead and try it from me though. That being said your fuel should not burn unless oxygen is available, beware, a danger exists when running at low air pressure, where the combustion will take place inside the burner tube or at the orifice itself.

There has been so much info already linked and posted from people speaking from experience, the sources of which are tried and tested proving functionality. You have already posted pics of burners of which the flames just needed some tweaking from either increasing fuel available or reducing oxygen input.
I don't want to tell you to stop building but you should, you are nearly there and have the persistence, you just need the knowledge......research.

If you change anything, change 1 thing only at a time and test all parameters available, eg air input volume, gas/fuel input volume and observe, from that deduce your hypothesis make 1 single change, re test and observe.

 

[saadat68]

I made a propane burner before. The nozzle block air flow in my burner because I can not find 1/8 inch pipe so I used 1/2 inch and it blocks the air
http://uupload.ir/files/xod8_img_20170902_210351.jpg

Do you know what is this flame ? I think it is reducing flame

 

[Lightspeed]

Saadat68, is that with the blower running?

If you are using a blower the reality is if properly set up you should be using less fuel for the same temperature than a venturi burner. What does that mean? It simply means if you are using a blower that is ramming an excessive amount of air for your needs, you in turn need to provide it more fuel to keep the thing lit.

That flame is looking close to right, but it is excessive for your furnace. Play with the air input first and see the effect it has, observe and record changes/settings with phone camera for reference, you will see the flame change characteristics.

Less air pressure: the flame will go more yellow and softer in appearance as the mixture is more rich with fuel also losing some of the audible roar.

Reducing flame; More Fuel/same air pressure: Will produce similar effects to Less air pressure, by making the mixture more rich, flame colour will become more yellow and softer in appearance with smoother tips around the end of the flame, the flame will become quieter audibly.

Oxidising Flame; Less Fuel/same air pressure: Will produce a more Blue flame, the flame tip will display sharper flickering tips around it and also become more audibly noisy/roar.

After playing with air pressure, while keeping the pressure lower, try lowering the fuel output and observe and record with phone camera. By doing this you will easily see the flame types and find an workable flame setting range for the burner giving ease of adjustment

Flame types are actually simple, I have already posted a link on how to tell them apart along with the specific indicators of each type. You need to assess the individual characteristics of the burner you have made, and adjust accordingly from your baseline testing. Patience and observation is required. 1 change at a time ONLY.

Do you have a lid for your furnace? you are going to need it or you are going to lose all your heat. In amongst the links I posted there is information on exhaust size and is directly relative to Burner size.

I hope you can wind that thing down so you can heat your refractory and crucible to operating temperature slowly without destroying them by sticking a rocket engine in front of them while they are cold.

 

[Palladium]

You don't need an orifice. Propane will not burn back into the tank. Fire is a chemical reaction. It requires an accelerate and an oxidizer. It has a propagation rate. That's the rate at which the chemical reaction occurs according to the available oxidizer. Think of it as a beaker of hcl with gold in it. Just hcl and nothing happens. Now add an oxidizer like cl or nitric and the reaction proceeds. Remember i told you you needed like 23 to 1 or 25 parts air to 1 part gas for it to burn? The line as well as the tank has a saturated solution of gas with no air to carry the chemical reaction forward, so their will be no fire to run back into the tank. He's right about the burner. The Reil burner i posted a diagram for will push an average of 150,000 btu's which is all you will need for that small furnace. The larger the diameter of the pipe for the burner the more btu's you have to push to get a balanced flame, hence a Saturn 5 rocket! 1 inch is all you need. I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.

 

[Palladium]

If you used two of these like the one you bought it should work. If it doesn't put out enough heat fast enough then take a small drill bit and increase the orifice size of each burner a little at a time until you reach the desired result.

 

[saadat68]

Thanks

Lightspeed
No It is reil burner

Because I had 2 inch pipe I made this design and without any orifice
http://anvilfire.com/21centbs/forges/gasburn1.jpg

Didn't work !!!
OK I will find a solution
Maybe one inch works
I will go for find a 1/8 pipe for reil burner too.

 

[saadat68]

If you used two of these like the one you bought it should work. If it doesn't put out enough heat fast enough then take a small drill bit and increase the orifice size of each burner a little at a time until you reach the desired result.

Sorry palladium
Do you see my video ?
It is for 2 days ago with 1 mm orifice and 1-1/4 inch pipe
http://iranbm.com/saadat68.mp4

It's flame is like shop burner but stronger. Can I use it ? Maybe with one inch pipe and redesign it I will get better flame too

 

[Palladium]

No need to change anything. Take it out of that other blower and pipe, put the head back on it like it came in the picture i posted above. Remove the orifice that came with it and drill the orifice a little bigger to let more gas through. Reassemble and test. Before you drill the orifice try boosting the pressure. Twice the pressure equals twice the gas without drilling the orifice.

 

[autumnwillow]

I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.

Would you mind sharing the size of that furnace?

I'm currently building one so I'm not sure with the sizes of the burner pipe yet.

 

[butcher]

Been too busy to follow the thread, just watched the video and seen that burner is roaring.
It would work in a larger furnace.

I like seeing the progress you have been making and especially see you learning so much in your goal of making fire and your burner.


Fire is a simple chemical reaction, heat, fuel and air, we just need to get the right reaction going and feed it what it wants, lately I have been busy trying to remove the fuel to keep the fire from burning. while you have been trying to get the fuel to burn with the right amount of air.

I am kind of lost where your at with your furnace or burner, but I enjoy seeing the progress.

 

[Palladium]

I built a furnace with a large chamber for one of my first builds way back and the 1 inch was more than adequate.

Would you mind sharing the size of that furnace?

I'm currently building one so I'm not sure with the sizes of the burner pipe yet.

https://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=20874&p=215733&hilit=furnace#p215710

 

[autumnwillow]

Ahhh I see. Very nice work. The burner pipe size was relative to the exhaust size.

Correct me if I am wrong. After 3 years of usage from this type of casted furnace it is no longer usable due to cracks?


Sent from my SM-G920F using Tapatalk

 

[Palladium]

Nope! Still just as good today! I've moved on to a different furnace setup. That one was for fun, but i like to push things to the limit to see how they will hold up to my design and to find flaws. For my first one it surprised me. I ran it just like you see with the wood and all. It melted several hundred lbs of silver and would keep melting today if i fired it up. The secret is in the refractory and the way you cast and dry it. I built it with cracks. The main chamber is 6 pieces. The top, bottom, and then the chamber is broken into 4 equal sections. It can be dissembled and moved then reassembled like a jig saw puzzle. It really starts to rock and roll after about 1 hr. Once the thermal mass of the furnace stores energy it literally melts faster than you can feed it! I'll try and get some measurements tomorrow. I think the burner is 1 inch and the exhaust is maybe 2 - 2 1/4. I can't remember right now. If you make the hole to big you can regulate it by putting a fire brick on top and pushing it over the hole to adjust flow.

 

[autumnwillow]

What do you mean by you built it with cracks?
Are there existing cracks in the build that you just let it be? Is it causing problems? Heat leaking out perhaps?

When I was doing my research about DIY furnaces, most of the DIY guys used garden supplies and a common cement to create a refractory mix. Upon reading more, this was not good as cracks would often develop in a very short usage cycle.
So then, I found out about actual refractory cement that will last longer, so I tried to look for companies selling such and when I finally inquired I was advised to used bricks with mortar instead of a refractory cement.
Again, I did my research and it ends up that refractory bricks combined with refractory mortar are the best of all the three options that I have stated. As refractory bricks were properly heat treated in order to achieve such durability.

Although you could actually make a properly heat treated furnace with refractory cement that will match near the durability of a refractory brick. It is actually the spacing in between those bricks and mortar that make the furnace a lot more resistant to cracks.