Intro: Build a Propane Jet Burner - Brewing, Seafood, Wok Burner
In a previous Instructable I showed how to make a super sized propane jet burner with 4 burners. This is a follow up video after I received a few requests on how to make a smaller one. This is a single jet burner that I estimate pushes out around 80,000-100,000 BTUs.
This burner can be used for boiling large pots of water or oil for cooking seafood or deep frying. This burner heats things up in a hurry, I think I have a good design figured out. I already have one for my wok station (check out my Instructable on that too), deep fry station and one for boiling seafood.
The build requires some welding but it could be brazed as well or you can see if a welding shop or automotive repair shop will weld everything in place once the parts are fabricated and fitted. Total time of welding is less than 5 minutes. If someone was creative you could do it all by fitting everything and using some straps to hold all the parts together. Just welding it was much easier and faster. Regardless you can take this theory and make your own design too.
You may be asking why build a burner, I found it hard to find one to meet my needs, any of the commercial ones available do not push out the btu's in a focus flame like this. Once you have the cost of the high pressure regulator, you can run multiple burners off the regulator. The cost of each burner is around 15 dollars in materials.
Important Warning: Do not attempt this Instructable if you do not have experience with propane and how it burns. If you are not comfortable around propane do not attempt this. When propane is used properly it is a very safe fuel but bad things can still happen. This burner is very large and can damage you and your property. You have been warned, I take no responsibility if something goes wrong.
Always wear safety equipment when lighting and working on the burner. At a minimum, safety glasses or face shield, cotton long sleeves or leather, do not wear synthetic materials as if they catch on fire they will melt to your body.
Also do not use this burner indoors, it is suitable for use as an outdoor appliance only.
Step 1: Parts and Tools
- 3" OD x 6" Schedule 40 steel pipe
- 1/2 steel pipe High Pressure Propane Regulator or 3-5 PSI regulator (they are usually red in color)
- 1/2" steel pipe
- 1/2" steel cap 1/2" to 3/8" reducer bushing or
- 1/2" ball valve rated for propane
- Fittings to plumb the burner to the propane source
- PTFE tape or pipe dope
- Drill or Drill Press
- 1.2 or 1.3 mm drill bit
- Various hand tools
Step 2: Watch the Video
I recommend you watch the video to get a full understanding of how the burner works and is constructed. The written steps follow.
Step 3: Burner Theory
I will explain some theory on how came to my burner design. Propane will only burn at a very narrow fuel to air ratio. If the propane and air mixture is too rich or too lean it will not ignite. Where this becomes very important is sizing the burner tube and the orifice hole size.
This propane burner is a venturi burner, the basic operation is high pressure propane gas is forced out through the orifice hole, as the gas travels through the burner tube it mixes with air that is sucked in through the back of the burner tube.
I came to my design through trial and error. I started with a burner tube that I thought would give me the flame size I wanted (in this case 3" diameter) and then started with a small orifice hole and increased the size of the orifice until I could get the propane light. From there I tweaked the intake of the burner by restricting it using tape. I found if the intake was too large the propane would burn at high propane flow but once I turned it down it would go out, restricting the air allowed it to burn at lower propane flow. Don't mistake high pressure vs high flow, you can have high pressure but low flow.
Step 4: Body of Burner
The body of the burner is just a piece of 1/2" steel pipe with threads on each end. One end is capped off with a steel cap. I had left over 1/2" pipe from other projects so I just welded the end closed and welded on a 1/2 thread coupler but it's easier just to buy the pipe and cap. The length for mine was around 14" but you can make it as long or as short as you like.
Depending on the propane regulator you get and the size of the fitting on the hose you will need to get a coupler and reducer bushing to plumb the 1/2" pipe to the hose.
Step 5: Drilling the Orifice Hole
The orifice hole was drilled into the 1/2" pipe, the location is up to you, I put it in the middle of the pipe. I first filed flat the tube so the hole could be drilled easily, prevents the drill bit from skating. The sizing of the orifice hole was determined by a process of trial and error. I eventually landed on a 1.2 or 1.3 mm hole, I found 1.3 mm produces a nice strong flame but 1.2mm burned slightly cleaner.
Also a tip is if you have a drill with a chuck that will not grasp a tiny drill bit, use some metal tape and wrap it around the drill bit to build out the diameter of the shaft. It should hold tightly in the chuck.
Step 6: Weld on the Burner Tube
The burner tube is welded in place on the 1/2" tube, centering it over the orifice hole. If you don't have a welder you can get a mechanic shop that does metal repairs to tack it in place for you or it can be brazed in place as well.
Step 7: Weld on the Feet
The feet to hole the burner up right is made up of some 1" angle steel. Two pieces were welded to the body of the burner. For my application the burner will be mounted to a deep fry station so I drilled some holes in the feet for mounting.
Step 8: Plumbing the Burner
To connect the burner to the propane can be done many different ways. I like using a quick connect as I have multiple propane appliances. But the hose and regulator can be connected directly to the burner. The fittings can be bought any place that sells pipe fittings for natural gas or propane. Where ever you purchase the high pressure propane regulator will sell the fittings to plumb it to the burner. Also make sure to plumb inline a ball valve, you will use this to control the flow of the propane to adjust the flame size.
Make sure to use PTFE tape on all fittings to ensure a leak free seal and test for leaks using soapy water.
Step 9: Tweaking the Choke
To tune the flame of the burner, some metal tape was applied to the bottom of the burner tube. This acts as a restricter plate or choke to reduce the amount of air entering the burner, helping to reach the correct propane to air mixture. You can figure this out yourself: if the flame goes out when you turn down the propane then you probably need to restrict the amount of air.
On this burner I taped 1/4 of each side of the bottom of the tube (see picture).
Step 10: Electric Start (optional)
Lighting of the burner is done using a BBQ lighter or long match. But to make things easier a electric start was installed. You can find them in the BBQ section at the Home Depot or Walmart. The ones with batteries work much better than the single push button type and only cost slightly more but both types work fine.
Installation is simple, there are two lead wires that connect to the power module, one of the wires goes to the body of the burner as a ground, the other goes to an electrode. Two holes were drilled in the burner tube, a hole was tapped for a bolt so it could be screwed and held in place. This acts as the ground and one of the electrodes that came with the kit was installed in the second hole. They should be installed close together so the arcing happens over the flow of the propane. (see pictures)
A coat of high heat BBQ was applied to the burner to prevent rusting.
Step 11: Testing and Mounting
Lighting the burner is simple the propane was kept at a low flow and the pressure around 2-5 psi, using a BBQ lighter apply the flame to the middle of the burner tube while the propane is on. It will light with a roar! To adjust the flame size I use the ball valve.
If you follow the theory and construction the burner should work just fine.
Good luck and be safe.