Sunday, November 29, 2009
I have two doors for my oven. One door is made of wood, but has a steel backing (see earlier post), and this is used after the fire is out. The door is then set in place when baking bread.
The other door, that I just adapted today is used while the fire is burning. What I did was to cut the top of the door, but I left a space at the bottom of the door so that when it sits on the hearth, it doesn't sit on it completely.
So, there's a large space at the top of the door for exhausting the smoke and a small space at the bottom for constricting the flow of oxygen that the fire is calling for. This definitely makes it easier to start and maintain a fire. I believe this is called The Venturi effect.
For the scientifically minded, the Venturi effect is a special case of the Bernoulli effect, in the case of fluid or air flow through a tube or pipe with a constriction in it. The fluid must speed up in the restriction, reducing its pressure and producing a partial vacuum via the Bernoulli effect. It is named after the Italian physicist Giovanni Battista Venturi.
Without a door like this, the fire seems to be buffeted from all sides and does not burn as well.
The two bricks in front of the door are there to keep the door in place.
Posted by Breadhunter aka Stu Silverstein at 10:48 AM