Sciencemadness Discussion Board

DIY bunsen

TinSandwich - 12-4-2016 at 12:13

So I will be trying to make sodium metal trough eletrolysis in a bit but before I did that I wanted a way to keep it molten for long periods of time (so that I can do the electrolysis), so I decided to build a bunsen burner.

I started with a tube and with some pipe fitting I attached it to my gas tank (everything nice and secured with teflon tape), I tried it out just to confirm everything was right and a nice yellow flame came out.

I then tried to create a nozzle by soldering one ofthese to the tube and then made some holes in the side of the tube to let the air in and take advantage of the venturini effect.

And that's where I've gotten so far: the flame is still yellow and gas leaks from the holes in the bottom (so probably I don't have enough pressure to porce the gas to the top).

Ps: I know I could use a torch to do the same thing but I wanted to build something, also does anyone know how much would an actual bunsen burner cost?

Here is a sketch of what I made (I tried my best):


_
/ * \
(***) <--yellow flame
\***/
\*/
|....|
|....|
|....|
|....|
|....|
|....|
: ...: <--holes
|./\.| <--nozzle
|
L_________gas tube and tank




[Edited on 12-4-2016 by TinSandwich]

[Edited on 12-4-2016 by TinSandwich]

violet sin - 12-4-2016 at 12:27

The orifice at bottom of verticle body is important. It is what determins the speed of fuel gas passing your openings for oxygen, and therefore the ammount of mixing caused in the chamber. A small hole will jet the fuel rapidly past the holes making for great mixing. It sounds like yours is too large. The gas can just fill the tube without mixing and come out the holes.

The effect is huge on one of the copper coil alcohol burners that youtubers love. If you get it right, works like a charm. Too small and the alcohol vapor cant sustain a flame, velocity is too high. Too low and you get a big lazy flame that doesnt cook well(or heat the coil to make the thing work right. I was able to make a poor attempt at nitric acid some years back with one of the coil burners. It worked great, acid production was deffinitely NOT working awesome. When done i did have one solid puck of salt so it got pretty warm.

chemrox - 12-4-2016 at 16:15

As above and you really need a needle valve for the gas inlet and an adjuster for the air. These parts should be machined for the specific gas. If you must do a DIY why not make something that won't blow up like an adjustable lab stand. Bunsen burners are cheap. Just get the right one for your gas.

violet sin - 12-4-2016 at 23:24

A needle drill set is about 15$ at the local ACE here, but they are much cheaper elsewhere. It consists of a brass handle that screws down on drill bits(ya, small like needles) similar to an exacto blade takes a new razor. They are just great for making small holes in stuff. The ball fill tip could be used but i would cut it back to a stub. You want one hole pointing down the length of main body tube, terminating prior to the vent holes so it blows past them specifically on its way to the flame. So the two side facing holes on your linked pic would not be helpful.

Air inlet adjustment is as easy as a tightish fitting ring over intake holes in the mixer body. This would have a tapered opening in it you slide around the intake, covering or revealing the actual intake hole. Blocking most of the intake would likely result in fuel gasses coming out like you already have unless it is all planned to work like a store bought.

As far as machining the orifice to receive a specific gass, trial and error could quickly pay off. And im sure reasonable sucess could be had in putting the needle or ball valve inline somewhere in the gas supply hose. Not going to be as easily controlled as a nice store bought. Not sure i would trust seals on something found in the hardware store getting hot at the torch end. Even reflected heat from the bottom of you ring stand/mesh square/flask could be enough to torch an improperly selected valve seat/o-ring.l

Above all else, if you attempt to use something home made, plan for the worst case scenario happening at any moment. Select the correct location for things to go wrong, ie. Not a basement. Never leave it unattended while on, and always disconnect the bastard when not in use. It would be shame to have a slow leak fill a room overnight leading to a chaotic re-distibution of your home to a pile of wood splinters and possible(probable) loss of life. The question is... Do you trust your skillz as a maker... To plug and play with fuel gas?
I
By far the safest option is buying one. But making one(if you have the skill) could be fun. I don't think it is magic, un-tameable or so problematic as some would lead you to believe
(Violet sin is not responsible for your choice to continue or modify your project, or any property/bodily/etc. damage)

Also have to say i love the user name "TinSandWich" :) good one

JJay - 12-4-2016 at 23:29

Doug's Lab used a large homemade Bunsen burners (for making copper chromite IIRC), but I don't remember seeing any details on its construction.

TinSandwich - 13-4-2016 at 03:37

Quote: Originally posted by violet sin  
A needle drill set is about 15$ at the local ACE here, but they are much cheaper elsewhere. It consists of a brass handle that screws down on drill bits(ya, small like needles) similar to an exacto blade takes a new razor. They are just great for making small holes in stuff. The ball fill tip could be used but i would cut it back to a stub. You want one hole pointing down the length of main body tube, terminating prior to the vent holes so it blows past them specifically on its way to the flame. So the two side facing holes on your linked pic would not be helpful.

Air inlet adjustment is as easy as a tightish fitting ring over intake holes in the mixer body. This would have a tapered opening in it you slide around the intake, covering or revealing the actual intake hole. Blocking most of the intake would likely result in fuel gasses coming out like you already have unless it is all planned to work like a store bought.

As far as machining the orifice to receive a specific gass, trial and error could quickly pay off. And im sure reasonable sucess could be had in putting the needle or ball valve inline somewhere in the gas supply hose. Not going to be as easily controlled as a nice store bought. Not sure i would trust seals on something found in the hardware store getting hot at the torch end. Even reflected heat from the bottom of you ring stand/mesh square/flask could be enough to torch an improperly selected valve seat/o-ring.l

Above all else, if you attempt to use something home made, plan for the worst case scenario happening at any moment. Select the correct location for things to go wrong, ie. Not a basement. Never leave it unattended while on, and always disconnect the bastard when not in use. It would be shame to have a slow leak fill a room overnight leading to a chaotic re-distibution of your home to a pile of wood splinters and possible(probable) loss of life. The question is... Do you trust your skillz as a maker... To plug and play with fuel gas?
I
By far the safest option is buying one. But making one(if you have the skill) could be fun. I don't think it is magic, un-tameable or so problematic as some would lead you to believe
(Violet sin is not responsible for your choice to continue or modify your project, or any property/bodily/etc. damage)

Also have to say i love the user name "TinSandWich" :) good one


Yeah I figured I should buy one, it was just a fun weekend project :). I'll have to take a trip to the store where I buy my supplies anyways so I guess I'll ask if they have a decently priced bunsen.

My username "Tinsandwich" is actually an alternative name for the blues harmonica. It's not related to chemistry but it sounds good and it's got a bit of history behind it:D