cone shaped forge

JTknives

JTknives

Joined
Jun 11, 2006
Messages
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i was thinking about a forge design to day that i would see what you thought. it would be a pipe forge cast from say kast-o-lite 30. the front door would be a 4" hole and the back door would be a 2" hole. the cast lineing would be in the the shape of a cone on the inside so it got smaller as you went back. the burner would be mounted twards the back. the rushing flame would inter and start to spin and the centrifacal force would make it travle where it can grow in size. kinda like tornado. what ya think.
 
My gut tells me that one of 2 things (or possibly both) will happen.

  1. There will be a nasty heat differential and the rear of the forge will be very hot.
  2. There will be incomplete combustion at the rear of the forge due to the restricted space and you'll have a very oxidizing atmosphere back there to turn all your steel into scale.

Not saying I know what I'm talking about, but my gut tells me that these are likely scenarios. What's wrong with a standard tube? Better yet, if you're using castable refractory, why not make a Zowada style spherical chamber? That's about as efficient and even heaing as you can get.

-d
 
JT., maybe a small torch burner model might save some time and money on experimenting? Keep at it and you may come up with a really good design. Good luck. O.
 
Thats much like a blow torch works, with the air coming in at the rear of the flame.
The main reason for building a symmetric design is the even heating that takes place. Thats what you want in a good forge. Even Heat!
Having control of the input air and fuel is the main consideration after size of the forge working area. You have to be able to tune a forge, after you light it.

Fred
 
the burner would be mounted just like any other pipe forge going in the side at the top of the chamber. the cone shape is to cause the flame to spin around the chamber and flow towards the larger door. front door could be say 6" and the back could be 4".
 
Jarod,.
If you want to build one like that for fun ( to see how it works) go ahead.
If you want to build one that works well, don't build it as a cone.
The fluid dynamics of a forge chamber require a few things to operate properly.
1) The chamber must be able to heat evenly.This will require a smooth and equal wall surface without corners. - ROUND-CYLINDER. A cone would have more surface in the front than the back, creating a very uneven heating.
2) The flame must spread out as evenly as possible to heat the entire chamber equally. This is accomplished by the angle of the burner to the long axis of the chamber, and the tangent of the burner to the circumference of the chamber. The flame should be directed along the chamber wall and at a 15-20 degree angle forward. A cylinder is condusive to this. A cone would make the flame travel at a different speed as it moved forward, allowing for uneven heating.
3) Atmosphere. The fuel/air mix of the burner is only part of the atmosphere. The outside oxygen that enters into the chamber affects it,too. If you made a cone shaped chamber with a forward facing burner, you would have a venturi effect that would draw air into the rear opening.By making the cone larger at the other end you would create a nozzle effect (think rockets) drawing the air in the back even faster.
Stacy
 
i dont think it would spin as much as you think, i would guess it will flow a bit but for the most part the smaller end will be hotter. not that i wouldnt be curious to try it anyway. if your going for spinning the heat flow to make a more even heat, i would consider a plain cylinder with the burner coming in at an angle.
-Lou
 
hey JT, google cone furnace and see what you come up with.

post your thoughts after you check it out. I got a new theory but I wanna see what you think first.

I've had square forges and round forges, the flame ina square forge
(if the burner is placed ona tangent) travels the same path as a round forge..

ina forge size matters, the burner needs to be sized to the forge.

to big a burner and the forge can not contain the heat output.

remember the guy that discovered micro wave metal sintereing? Nobody told him it he couldn't do it...so he did. :D
 
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