A beginner makes a burner

[joco-nz]

A little show and tell on an LPG (propane to some) burner I built in preparation for a home forge based off a 9kg (5 gallon) LPG bottle.

First some various bits and pieces to be made use of ...
Pressure controllable valve

One of two fittings for the 5mm ID gas hose. Notice the "fun" ball end that creates a gas seal.

MIG tip for 0.6mm wire. M6 threaded into some M8 2mm wall copper tube.

black pipe nipple. Some work has been done on this, one thread removed, the other will eventually be removed as well. Hit with a wire wheel, inside has been "reamed" with a 15mm drill to nock the worst of the weld seam off.

Now starting to make some of the brass fittings for th gas feed into the accelerator. This fitting is designed to mate with the ball ended hose bard from BOC. This barb is for the 5m of gas grade hose I got. The ID is 5mm which is just odd enough to not be able to take the standard 6mm barbs typically for sale in these parts. Starting brass is around 19mm from memory. The thread is 5/8-18 and the inserted area is a 60 deg taper (30 deg off center line).

The other side of this fitting is tapped BSP 1/4-19 and a standard BSPT 1/4 nipple is installed.

A gas grade ball valve is added along with another BSPT 1/4 nipple and another custom fitting that supports the copper pipe which will be threaded M8 into this custom adaptor.

Accelerator tube installed

The next step is the creation of a busing style coupling that the accelerator is inserted into with a close slip fit and which will be inserted into the burner tube. The intent is to allow this same accelerator to be used in this 1/2" burner and also into a yet to be built 3/4" burner.

So ... time to start on the burner tube. The 1/2" black pipe is mated with a 20mm ID galv section of pipe which will be the air control sleeve.

The ait slots have been made in the burner body, the control sleeve has been bored to size and the accelerator adaptor bushing sized to fit pipe.

The flare is created using some SS pipe kindly donated by Bruce E.

Some more work and the burner tubing all done.

And now on to th test firing. This has been done at night so you can actually see the flame. In normal sunlight its basically invisible.

[ame]https://www.youtube.com/watch?v=-b-VM6cVK4k&feature=youtu.be[/ame]

 

[MRA]

Hey, that's nice. I'm running on air-blown waste oil, which is much cheaper, and also much noisier, smokier, smellier and messier, and which leads one to stockpiling gallons of other people's mildly hazardous waste

 

[joco-nz]

Cheers . Some more tuning to do. I looked into waste oil burners but then I would need a place to source and store said oil. I have enough grief from SWMBO as it is.

 

[tornitore45]

I am not familiar with this type of design. Could you delight us with a mini lesson on how this burner is designed to work?
What does the accelerator does?
Where does the gas enter the larger tube? From the Accelerator tip?
How does the gas mixes with air?

Thanks

 

[joco-nz]

Mauro - This design is my take on the 1/2" burner described within "Gas Burners for Forges, Furnaces and Kilns" by Michael Porter. I'll annotate a picture of the overall burner and some of the key elements.

Cheers,
J.

 

[joco-nz]

Here are some annotationed burner pics.

The basic concept is that the accelerator increases the spped of the gas flow through a slowly reducing pipeline internal diameter. The length of the this is assembly is intended to allow enough length for this acceleration to happen. Idea is that maximum gas speed means improved Venturi effect which improves the amount of air that gets pulled into the burner tube.

Cheers,
James.

 

[jimsshop1]

Nice job James. I'm trying to perfect one of my own out of 1" pipe. May I ask what pressure you have the adjustable regulator set at?

Thank you from Pennsylvania, USA!

Jim

 

[tornitore45]

Thank you James for the clear and detailed explanation.

 

[joco-nz]

Jim - running around 6 psi. I’ve played with up to 12psi but other than using gas faster couldn’t see any improvement in the flame. Interestingly the flame stayed neutral. So the limiting factor might have been the 0.6mm MIG tip. I have some 0.8mm tips that are supposed to usable with a 3/4” or 1” pipe based burner tube.

My plan is to create the 3/4” based burner, which is supposed to be ok with either sized MIG tip, and use the same coupling concept to be able to swap accelerator between them as needed. The coupling is a close, feel the air suction style, sliding fit onto the accelerator.

Cheers,
J.

 

[jimsshop1]

James,

Thanks for the info. I'm using a .035 welding tip or somewhere around 8-9 mm. I was getting too much gas and not enough air so I am going to drop down to a .025 which is closer to what you have. I also did not have a regulator. I found though the flame changes characteristics once inside the enclosed furnace I made. It has a 3" hole in the top of the lid for feeding and I can slide up to a 1-1/4 burner in there. I'm still learning also. Thanks again and be careful!

Jim