Sciencemadness Discussion Board

Bunsen burner + Propane tank

trezza - 6-4-2011 at 08:54

Hello everyone, I want to buy a propane/LPG bunsen burner, But I'm not sure how I would go getting the tubing and regulators to hook it up. This is the Burner:
8mm inlet

And this is the type of Gas tank I want to hook it up to:


Saw a video of someone with a bunsen burner hooked up to a small portable Propane tank, but I'd rather use a large one like in the picture!.

mr.crow - 6-4-2011 at 09:09

You can get adapters to connect a large tank to a small tank appliance. Look in a camping or RV type store. Still need a regulator for the burner.

smuv - 6-4-2011 at 09:26

I did it with just a normal propane BBQ regulator from any hardware store, it has a nipple on the outlet, cut the stock black tubing off (you need pliers to cut the metal crimp) and replace that hose with vinyl tubing of the proper diameter, hold the tubing on tightly with hose clamps or a zip-tie.

The pressure is just a touch low for running a Bunsen burner, but it is acceptable. You can find adjustable regulators, but they are much more expensive.

bwpatton1 - 9-4-2011 at 19:04

I was looking at doing this, since my house is all electric. Does anyone know what pressure Bunsen burners need/prefer. That and the pressure the standard propane regulator puts out. I think I saw a cheap adjustable regulator with gauge somewhere....It was rated something like 0-30PSI.
Found it!-Adjustable regulator

[Edited on 10-4-2011 by bwpatton1]

Arthur Dent - 10-4-2011 at 06:27

Even the regulator from an ordinary propane torch can be used... Here's my setup.



Not a trace of leakage from the tube which is snugly inserted on top of the headless regulator. the only problem is that it's very sensitive at the lower end of the output scale, not much rotation between completely closed and a 3 to 5 cm flame.

But it works! I don't use it as much as I used to since I got my hotplate.

Robert

bwpatton1 - 10-4-2011 at 06:58

Wow, that is awsome. I would have never thought of that. I just might have to use that method as my dad has one of those torches he never uses! Thanks Arthur! Well, at least until I can afford the real set up. What kind of tubing is that? Is it just regular poly from the hardware store or is it some kind of gas tubing?

Arthur Dent - 10-4-2011 at 07:22

Yes, just plain transparent PVC tubing. Ideally, the orange/brown rubber tubing used in labs would be easiest to plug in / pull out and it's much more flexible, but the PVC does a great job.

I wouldn't recommend translucent poly tubing because it's just not flexible enough and you would run the risk of having your bunsen burner flip on its side if you move the tank while it's in operation.

Be careful, when the regulator valve is fully opened, the flame can get as high as 2 feet!

Robert





bob800 - 10-4-2011 at 08:18

Avogadro's Lab Supply also sells an (overpriced) regulator specifically for Bunsen burners: http://www.avogadro-lab-supply.com/item.php?item_id=379. It works well for my burner, but Arthur's suggestion is probably better if you don't want to pay a ridiculous $45!

Magpie - 10-4-2011 at 08:42

More info:

http://www.sciencemadness.org/talk/viewthread.php?tid=14588#...

Formatik - 10-4-2011 at 09:36

Quote: Originally posted by Arthur Dent  
Even the regulator from an ordinary propane torch can be used... Here's my setup.


...


A note on this setup.

Do not tilt the propane canister horizontally while heating, because after some time liquid propane will come out into the tube if done so. And then an out of control flame develops because the liquid in the tube starts evaporating into larger volumes of gas. Keep the canister vertical.

If you do tilt the canister, then use only a slight angle maybe around 50ยบ, and then constantly keep an eye on it. I have left one alone before when heating something for a few hours (never a good idea, at least it was in a mostly cemented area), but because the canister had a tilt, an out of control flame formed and torched what I was heating worse even burning the cork on the clamp creating a ton of smoke and triggering a very loud fire alarm, that took a while to turn off.

I also suggest to use two separate clamp stands with clamps, one to hold the middle of the Bunsen burner, another clamp to grab the torch regulator wherever best either around the torch snout near the middle or around the circular fitting. That's just to keep them in place, and to further reduce fire danger from this type of setup.

I use shorter tubing, but this is for convenience. I also position the tube-in part of the Bunsen away from what I'm heating when a third clamp holds the flask, etc. in case the glass or ceramic container breaks, it shouldn't slice into the tubing.

mr.crow - 10-4-2011 at 16:43

I like the idea of hacking a propane torch. The torch also has a tiny hole to regulate the flame. Will this interfere with the Bunsen burner?

Arthur Dent - 11-4-2011 at 16:11

@ Formatik: I second all of your recommendations. The setup seen above was hastily put together for the photo, but when I used that setup, I did use a test-tube clamp, which fit precicely the threaded fitting of the torch and I had a long piece of orange tubing that I used to hook-up the burner to the tank.

I found that the PVC is quite flexible but not as much as the medical grade rubber. So your suggestion of using a clamp on the burner itself is indeed good advice.

@ mr. crow: When you prepare the torch for usage with a bunsen burner, when you unscrew the burner head on the angled output tube, you'll see a small fitting with a tiny hole at the end of the threaded tube, you must slide it out and remove it because if you don't, the pressure of the gas will push it into the tube get stuck in it because the torch head isn't there anymore to hold it down...

Robert

trezza - 11-4-2011 at 17:03

I have one of those blue cannisters for a blowtorch but it is a 65/35 propane/butane mix, would they be safe to use?

Formatik - 12-4-2011 at 05:13

Butane is liquid at a much higher temperature than propane, and the cold from the tank could cause or promote it to condense in the tubing. I don't know for sure. If you are working in warm temperatures (and keeping it upright), I doubt any liquefaction happens.

Once an out-of-control flame develops, it can be quite intimidating, because it can not be turned off after having turned off the torch regulator, you just have to stand by as the angry flames subside.

I've used mainly vinyl for tubing. Polyethylene is too hard, it makes the fits more difficult and less snug. Vinyl is also said to have good compatibility with natural gas, so it should be as good with propane. I have not noticed any cracking, etc.