Burner efficiency?

[Daniel Macina]

Can a Venturi burner be as efficient or near as efficient as a blown burner? You always hear that blown burners are much more efficient because they only run them at say 2 psi as opposed to a Venturi burner that they run at say 10 psi. But with a blown burner you're just dumping gas through an unrestricted hole. With a Venturi you're shooting gas through a very very small hole You might run a Venturi at higher psi but does that necessarily mean that you're using more propane?

 

[KenH]

I think the reason the blown burner forges are considered "better" is because the blower puts more air into the forge allowing more gas to be used, thus running hotter. Perhaps there is better mixing also which would help efficiency. There is only so much energy in a cu ft of gas, the only trick is to get as much of it as possible when burning. This needs the "best" air/gas mix ratio.

My forge is venturi, but I've been wanting to put a blower on it - just don't do enough forging. Maybe with cold weather coming on I can do more?

 

[DanF]

If both are well designed, both are efficient. I have more control over chamber temps with the blown burner.

 

[Daniel Macina]

The only reason I hesitate not to do some sort of a blown burner is i fairly frequently lose power in my neck of the woods and I'm scared to think of what would happen with that blower went off while the Forge was running. I really do enjoy working with Coal but it is getting harder to find, getting more expensive, and I am somewhat concerned about the long-term health risk of burning coal. I flip-flop too much just need to pick one instead of trying to find one that will do everything and eventually just build several forges. It's very hard for me to make up my mind on what to do on some of this because I have very little money for knife making so I just get One or two big projects done a month. Getting my new grinder built then the next project will be A propane forge of some sort. I've never really run a propane forge that I liked ( mainly because I can never get the burner angle correct.) so I'm just trying to figure out what route to go.

 

[Von Gruff]

I am a proponent of the venturi burner and whether it is because of the size of my forge or the 3 small burners but when I HT some stainless blades this morning it took less than 5 minutes to get it to heat (1960F) at 10lb then drop it back to under 2lb to maintain that heat.

 

[DanF]

Can a Venturi burner be as efficient or near as efficient as a blown burner? You always hear that blown burners are much more efficient because they only run them at say 2 psi as opposed to a Venturi burner that they run at say 10 psi. But with a blown burner you're just dumping gas through an unrestricted hole. With a Venturi you're shooting gas through a very very small hole You might run a Venturi at higher psi but does that necessarily mean that you're using more propane?

Daniel, I think you said it, the Venturi has a very small aperture, so, trying to compare the blown psi to the venturi psi is like comparing apples to oranges (kinda like your finger over the end of a water hose, yeah, I know it's more complicated than that).

If I had not wanted to heat treat or forge larger billets, my Atlas mini is a gas-sipping 'lil fool and i would not have needed the blown. But, the chamber is small so it gets very hot, from forging temps to welding temps, but is just about impossible to take down lower than just under 1500F

If I had your concerns with electricity outages, I'd go with a venturi with a larger chamber than the mini's.

 

[Daniel Macina]

I could put a solenoid on a blown burner that would cut off the propane if the blower ever lost power but they are fairly expensive and by the time I buy a decent blower and Got some castable it would be a pretty expensive Forge and I just don't know if I want to spend quite that much just yet. It would be a great forge through.

Thanks for putting up with my rambling and repetitive questions. LOL. I have a Ron Reil burner I started probably two years ago and never finished maybe I'll finish that out and just see how I like it. So many options, so little money.

 

[DanF]

I almost could not believe the $$ I had in my blown forge by the time it was finished, but my wallet believed it!

 

[Daniel Macina]

If I built my blown ribbon burner Forge it would be just like @Vombrown forge. I love that Forge. Just don't know if I have the money for the castable. Even if I built a smaller One then he has I believe I would still need at least two bags of castable.

 

[Vombrown]

If I built my blown ribbon burner Forge it would be just like @Vombrown forge. I love that Forge. Just don't know if I have the money for the castable. Even if I built a smaller One then he has I believe I would still need at least two bags of castable.

Daniel, I used exactly 2 bags for 2 ribbon burners and the forge. You can figure out the cubic feet of wet castable per bag and calculate it backwards to get the size if you want to use 1 bag. I feel like the size I built was the optimum size, well I won't "outgrow" it for the foreseeable future. Whatever you do don't build it too small. it won't be long before you were wishing you saved a little more and built it larger.