Sciencemadness Discussion Board

Turning normal Bunsen into a propane one

NEMO-Chemistry - 8-9-2016 at 09:55

Hi

Is it possible to use a normal Bunsen with a propane/butane gas bottle? ideally without having to swap the regulator.

I noticed on bottled gas the flame is too high and normally blows out, so will opening up the hole in the gas outlet on the bunsen decrease the pressure enough to use it?

If so any idea what size hole? I have a heating mantle but a bunsen would be handy now and then, not handy enough to warrant the spending of money on though :D.

Dr.Bob - 8-9-2016 at 10:09

Most Bunsen burners are set up for natural gas, they need a different orifice for propane. Simpler to buy a propane one, or just use a torch head for a propane cylinder, as finding the right parts will cost more than a new Bunsen burner, and is not trivially swapable in most cases. And you can use a propane torch for so many useful things. I use them for fixing chips in glass, soldering pipes/wires, and much more.

Mailinmypocket - 8-9-2016 at 10:12

Shouldn't be a problem, in my experience anyways. It sounds like the gas is coming out too fast, what kind of regulator are you using?

For bottled gas I find that a blowtorch attachment for small propane tanks is best. Just unscrew the burner head and keep it, and plug your tube on the end of the gas pipe and secure it safely. It Gives very fine gas flow control to allow you to experiment and get it working well.


Mailinmypocket - 8-9-2016 at 10:24

Oh maybe if it's for natural gas my method doesn't work. I got mine from a lab but I always assumed it was natural gas in the taps. Looking at the burners though they are printed with LPG and the other "Cylinder". Does yours say anything on the base?

Maker - 8-9-2016 at 10:44

I've got a natural gas bunsen I use with a propane tank. It works but the flame is about 8 inches long (Safety flame is about a foot and a half :o ), it really needs a nozzle with a smaller orifice.

XeonTheMGPony - 8-9-2016 at 12:10

Natural gas uses a larger orifice as it contains less energy per unit volume then LPG

LPG uses a smaller orifice..

It will be simpler to make your own or buy one, in an emergency I have had to hone out LP jets to work on Natural gas.

NEMO-Chemistry - 8-9-2016 at 13:23

Cheers guys, looks like i had the orifice hole the wrong way around! I thought opening it up would help but seems like i need a smaller one.

I can buy a special regulator but thats £25, or i like the idea of a propane torch head.....

Dont know at the moment, at least i know i cant do it the way i thought. I have 6 natural gas ones i got from school, but we cant get natural gas at home. I might buy a special regulator with flow control on it.

We use mainly Bunsen burners at school, i like the speed you can heat at and the fact you dont ruin the burner by spilling stuff on it :D

Dr.Bob - 9-9-2016 at 06:06

If you have extras, you could try to modify one, but might not be trivial. If you know someone in a machine shop, they might be able to modify the orifice, either plug the hole and redrill it, press it to squish the hole some, or put a tiny nozzle in the existing one. I don;t think a regulator will help much, it is the flow, not the pressure that is the issue, and while they are related, it is hard to do it that way.

NEMO-Chemistry - 9-9-2016 at 06:57

I wonder if that JBweld stuff might be useful? cover over the hole completely and then redrill...

Sounds like a 'bored on Sunday' Job :D.

Morgan - 9-9-2016 at 07:40

Stoichiometric air-fuel ratios of common fuels
Fuel By mass By volume [1] Percent fuel by mass

Natural gas 17.2 : 1 9.7 : 1 5.8%
Propane (LP) 15.5 : 1 23.9 : 1 6.45%
source: wikipedia, http://en.wikipedia.org/wiki/Stoichiometric

By volume was interesting
http://wiki.gekgasifier.com/w/page/6123822/Stoichiometric%20...


[Edited on 9-9-2016 by Morgan]

zed - 16-9-2016 at 14:38

Geeze, I've done that. Propane through a Bunsen Burner, worked fine for me.

The torch attachment to a hand-held propane cylinder, has a volume/pressure adjustment on it.

Of course, your Bunsen Burners and Propane cylinders, may differ from mine. And, you might require a finer gradation of flame control.

Me, I just unscrewed the burner tip, leaving the control knob in place. Then I slipped some latex tubing over the threaded tube end, and attached it to my Bunsen Burner.

Might or might not be good for a gentle flame. If you need gentle, perhaps a spirit lamp?

At any rate, works for me. Got no natural gas in my house. I was very impressed when a natural gas leak, leveled one of my neighbors houses, some years ago. Not for me, baby!

PS. There is a wire stand available, that holds yer handheld torch at a friendly angle, for Bunsen Burner duty. At least, there used to be.

Change; I am against it.

[Edited on 16-9-2016 by zed]

[Edited on 16-9-2016 by zed]

Chemetix - 26-9-2016 at 02:34

I stick a small piece of stainless steel mesh in the outlet of the burner to give more complete combustion of the gas, and with some crimping, allow for low flow rates. It's a bitch not being able to use natural gas, so many of my burners are designed for natural gas or Erdgas as the Krauts term it, but I cant get town gas at my work without paying a fucking fortune. This is a topic of interest as I'm working on a fuel generator to mimic town gas. I'll post with results of course.

zed - 5-10-2016 at 10:36

Since America has started fracking, we are awash in ethane and propane. We cannot dispose of all of it, by mixing it in with "natural gas" (methane), because E and P...are hotter fuels. They pack a lot more energy per given volume.

Thus, plans were made, to sell this excess gas to Europeans for cracking.

Propane itself is a nice fuel, and pretty compressible. Popular for forklifts, and some commercial truck engines. Nice for welding and glassblowing, but special tips may be required. Though I have heard that tips normally utilized for acetylene may be usable in the short term.

I'm gonna check and see if someone offers a Bunsen Burner, actually designed for propane.

https://www.youtube.com/watch?v=kzF464RDzk4

https://www.youtube.com/watch?v=genlWhHpg2Q

Well, based on what I've seen on youtube, plus my own experience.......
with the right propane source, and the right bunsen burner, everything works fine, as is.

Of course, I'm in the U.S.. Here, equipment is inexpensive, shipping fees are reasonable, and delivery is almost instantaneous.

I realize guys in Oz and Blighty, may not have the same kind of access......and prices may not be quite so friendly.

[Edited on 5-10-2016 by zed]

[Edited on 5-10-2016 by zed]

[Edited on 5-10-2016 by zed]

Magpie - 29-10-2016 at 10:12

I'll add my experience with lab burners. I have the burners shown in the picture below. The two ss burners are Humbolt Tirrill and Meker burners, respectively. They are both marked "cylinder" which I'm interpreting as meaning non-natural gas, as natural gas would likely be hard-piped. The other two red Cenco burners were purchased from university surplus. All of these burners function satisfactorily on propane from the 14.1 oz cylinder shown. I must use the step-down regulator, however.

I have natural gas piped to my home for heating. I could get a tap installed in my hood. However, I really don't want the gas company's craftsmen mucking around in my lab.

lab burners.jpg - 153kB

[Edited on 29-10-2016 by Magpie]