Poker Burner

[doubletop]

I spent the weekend making burners. Primarily to remake the burner I had done for my 3"vertical boiler http://www.homemodelenginemachinist.com/index.php?topic=8687.0)](http://www.homemodelenginemachinist.com/index.php?topic=8687.0)[/url] now I have soem tubeing of the right size, but as I was making parts I thought I'd have a go at a poker burner having seen a picture of one Ora Banda had done.

Somebody had suggested making burners out of stainless rather than copper so I thought I'd give it a go. It turns out to be way cheaper than copper, so stainless it is from now on.

Cutting the burner barrels on the mechanical hacksaw. (very usefull tool and way easier than cutting by hand)

Tubes turned to size and base plates rough cut

Barrels and base plates silver soldered and bases turned down to the barrel diameter

Squaring off the end of the poker burner tube

Three jet holders ready to be silver soldered into the burners

Poker burner on first firing. This is very encouraging as it worked 'out of the box'

I had intended to drill three rows of 1mm holes down the length of the tube but had left drilling these until after I'd done the soldering, so I could get everything lined up nicely. However, the tube had hardend and after the first of the 39 holes I gave up. 13 cross cuts in the mechanical hacksaw and I was cooking on gas. It looks like the horizontal boiler I have been considering doing is feasible. I'm going to base it on SandyC 3" vertical I've just made (see link above) but offset the center tube, not include the cross tubes and add some end to end stays. The space end where the burner sits on the vertical will become the smoke box. I just need to redo the calcs to see if the flue, without the cross tubes, is still within safety limits.

 

[cfellows]

I really like that burner. Is there some more information on it somewhere? What kind of fuel is it burning? Also, what is that adjustment on the outboard end?

Chuck

 

[doubletop]

Chuck

Its using a Coleman gas cylinder, from the camping store, so quite compact. The regulator is from a commercial ceramic burner I have. I'll get some photos and possibly some drawings sorted and add it to this thread. Got a few chores to do first though.

Pete

 

[doubletop]

Chuck

I've not forgotten that I promised more details on this burner but doing the drawing has been taking me longer than it took me to make the burner.

Another pic though showing the gas cylinder. It’s Gasmate not Coleman but checking the Coleman site they did use this type at one point. And looking at their spare parts page one of their camping stoves used a regulator that looks remarkably similar to mine. The regulator I am using is from a commercial burner.

Basically it’s the mixer tube from Sandy’s burner, with the shoulder turned to fit a piece of ½” stainless tube.

http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=get155

A 160mm length of ½” stainless tube with 13 slots cut with a hacksaw at 1cm spacing and an end plug in brass. Now you’ll also see a length of 3mm rod passing through the tube. This acts a a gas deflector/mixer and a means of locating the burner when its installed.

That's all really

Pete

 

[Ora Banda]

Pete... this is looking good, congratulations on getting a flame first time. I've found that the flame characteristics can vary unexpectedly once the burner is installed. I'd be interested to see what you find when you get to that stage.

The use of a "gas deflector" is very interesting, I've not see that before... the usual approach is to not interrupt the gas stream coming out of the jet... looks like you are setting a new paradigm on this thinking !

 

[doubletop]

I have no claim to the gas deflector idea. One featured in Sandy C's drawing (see link above), the burner from Primus barbecue, I robbed the jet from and a commercial ceramic burner all have them so I assumed it standard practice to help mix the gas and air.

I have tried the poker down a 1" tube to see if it would work in a boiler configured that way and it doesn't. I assume theres just not enough air flow. After a short while the jet ignites, which isn't good. So it looks like it will be used in something like a hedgehog boiler similar to Firebirds "a small boiler". http://www.homemodelenginemachinist.com/index.php?topic=2092.0

Pete

 

[Blogwitch]

Ora,

You will find that with most gas burners that use a jet, you require something to get the gas swirling after it enters the burner. Especially with ceramic burners, otherwise you find that the jet of gas hits the far end and only burns at that side of the burner.

It is a bit of a hit and miss thing when you make your own burners, and I used to try the burners out before cementing the ceramic in, by placing a bit of brass rod into the gas flow, and moving it about until I found the optimum position, then silver soldering it in.

For square or oblong burners, I used to use a piece of brass angle, with the pointy bit facing the jet. This seemed to defect the gas onto the outside walls and did a very good job of dispersing the gas about.


Bogs

 

[cfellows]

Thanks, Pete. Hadn't checked here for a few days and just saw your response. So, is the brass thingy with holes attached to the input end of the stainless tube what you are calling the regulator, the part that you got from a commercial burner?

Thx...
Chuck

 

[kuhncw]

Hi Pete,

While looking at your burner, I noticed your lathe. Is the headstock production or was it fabricated to fit an existing lathe bed? With the squared off corners I thought it might be a fabrication. It is a very nice looking machine. What is the brand or name?

Thanks.

Regards,

Chuck Kuhn

 

[doubletop]

Chuck^2

Apologies. For some reason I didn't get a notification of your posts.


Chuck 1

The brass thingy on the end of the stainless tube is the mixer tube (take a look at the SandyC burner drawings in the downloads section e.g. http://www.homemodelenginemachinist.com/index.php?action=tpmod;dl=item175)

The regulator is the bit that screws onto the gas can and allows the gas flow to be controlled. I have no drawings for this and it does need to be right. My original jury rigged connections to 9kg LPG bottle either ended up in next to no flame or a conflagration as the whole burner erupted. I have seen drawings for these as the boating fraternity build their own gas tanks and regulators. (being of the UK persuasion when I say gas I mean propane/butane and not petroleum).

Chuck 2

The lathe is a 1930's/40's Lorch LL, and you are right the headstock is homebrew. That's how I got it, so something happened in its history. The motor bracket is Lorch as I found it in the original catalogs here. http://www.s1p.de/05_w/wzg/wzge/fkae.html

Hope that helps

Pete

 

[kuhncw]

Pete, thanks for the reply and the link to the Lorch information.

I have a Hardinge Cataract bed that would be a good candidate for a home made headstock, but I don't need another project at the moment. I'll save a copy of the photo of your lathe.

Regards,

Chuck

 

[doubletop]

I went to my local MES the other day and had a rummage through the library to find a copy of K N Harris "Model Boilers and Boiler Making". I get to page 94 and there's the poker burner. Virtually as my "make it and see what happens" version the key to my relative success may be this, quoted from the book.

"A safe proportion for burner holes or slits is to keep them slightly smaller in size than the thickness of the metal burner tube or plate this reduces the likelihood of lighting back"

(Model Boliers & Boilermaking , K.N Harris ISBN 0 85242 377 2)

In my case I used stainless tube 12.5 mm dia and 1.2mm wall thickness, only because that's what the supplier had in stock. The hacksaw blade is about 1mm. So I accidentally met the criteria. I can see that using 12mm copper plumbing pipe won't meet the criteria as the walls aren't 1.2mm. So maybe that's the trick.

BTW in the same book is a picture of the spirit burner Firebird has made "Vapourising spirit lamp" but the book is a MAP/Argus publication the same source as ME and MEW where the original article came from.

Pete