Blown forge-picture update

Fred.Rowe

Fred.Rowe

Knifemaker / Craftsman / Service Provider
Joined
May 2, 2004
Messages
6,848
DSC00595.JPG

DSC00589.JPG

The fuel/air mixture column, on the right, needs to be TIG welded. Last thing to purchase; the 18" stainless gas flex lines to hook the fuel/air column to the forge body.
The 137cfm blower is mounted under the table, below the column. The knob at the base of the fuel/air column controls the air volume.
The control panel below the forge carries the low and high fan controls along with needle valves for the low and high burner settings.
The pid control had not been installed in the panel when this pic was taken.

I hope to have it ready to fire by the end of the month.

Happy to answer any questions, Fred
 
If I understand you, you are mixing the fuel/air in the column, and piping the mix to the burner ports? I would advise you to consider that pressurized fuel/air mixture is highly explosive.
I would sugest that you inject the fuel at each burner port. That allows the burners to be fine tuned individually to avoid hot spots, and keeps the mixture point at the burner flare.
Stacy
 
bladsmth said:
If I understand you, you are mixing the fuel/air in the column, and piping the mix to the burner ports? I would advise you to consider that pressurized fuel/air mixture is highly explosive.
I would sugest that you inject the fuel at each burner port. That allows the burners to be fine tuned individually to avoid hot spots, and keeps the mixture point at the burner flare.
Stacy
Click to expand...
I am mixing the fuel air in the column and piping it to the burners. I know this is not the normal approach. The entire assembly will have to be air tight.
I have another forge that is built on this principal that has been in use for the last two years. It is very accurate and burns quite smoothly with no malfunctions. The blower on this system is always on. I have never had the flame burn anywhere but the burner tips.
I am interested in any input you can give, Stacy.

Thanks Fred
 
If it has been working for you, maybe it is OK. But consider this scenario:
You are forging, with the system cranking away as normal. The power goes out/you trip on the cord/fan motor burns out . What might happen to the flame? Could it flash back ,up the air/fuel filled tubes to the air/fuel filled metal cylinder. ( Propane cylinders filled with propane and oxygen are commonly used as bombs in other parts of the world.) There is a very good reason that fuel and oxygen are mixed at the final point before the torch tip in welding (and why flash back arresters are required on job sites).
Stacy
 
bladsmth said:
If it has been working for you, maybe it is OK. But consider this scenario:
You are forging, with the system cranking away as normal. The power goes out/you trip on the cord/fan motor burns out . What might happen to the flame? Could it flash back ,up the air/fuel filled tubes to the air/fuel filled metal cylinder. ( Propane cylinders filled with propane and oxygen are commonly used as bombs in other parts of the world.) There is a very good reason that fuel and oxygen are mixed at the final point before the torch tip in welding (and why flash back arresters are required on job sites).
Stacy
Click to expand...
Stacy,

Good point! I do have the fuel running through an electric solenoid that is normally closed. It would close if the power were to go off.
The other forge is set up this way also.

They are calling me for dinner. I'll get back with you on this.

Fred
 
bladsmth said:
If it has been working for you, maybe it is OK. But consider this scenario:
You are forging, with the system cranking away as normal. The power goes out/you trip on the cord/fan motor burns out . What might happen to the flame? Stacy
Click to expand...

I have been wondering about this scenario with my forge. It is just a simple blown forge similar to indian george's design with the propane injected at the elbow. I know the pipe isn't going to explode in my case, but will it just flare up? I imagine the flame would go both ways, out the burner and the fan? I put a ball valve in the propane line for quick shut off just in case.

Fred, that forge looks really sweet.

-Mike
 
Mike,
With the injection at the elbow, and the injector facing toward the flare, the burner will operate as a (very poorly balanced) venturi burner if the blower is off, so you have little to fear. In Fred's setup, the mix point is so far from the chamber, that the flame would most likely come back toward the fuel source. One reason the blower arm is pointed upward in many setups is to prevent the propane from falling and pooling in the blower housing ( heavier than air). Fred's use of a solenoid is a good feature. It won't stop a back flash, but will greatly reduce the amount of fuel available to ignite.
Stacy
 
full flow check valves would also be an option for flash back. All my oxyacetylene torches have them. Great looking forge
 
ib2v4u said:
full flow check valves would also be an option for flash back. All my oxyacetylene torches have them. Great looking forge
Click to expand...
I did not consider the check valves as an option, but that would work as well.
Good idea!

Fred
 
You must log in or register to reply here.
Back
Top