Blower air pressure/volume

[Alex w]

I’ve recently made a forge blower out of a fan it doesn’t give off high pressure but gives constant air to my forge. It takes longer to heat up stock but is quieter than my other blower by a long shot. I’m just wondering if it’s enough and if not what I can do to improve it, if you have a suggestions. 

 

[Glenn]

Increase the air supply pipe between the fan and the fire to 4 inches. Make the adapter from 4 inch to reduce down to a usable size for the fire at the forge location.  This will allow as much volume as possible to get to the fire. Put a way to spill any excess air that is not needed.  Usually a opening between the fan and the air supply pipe of 3-4 inches is all that is needed on a strong fan. Aim the fan closer or reduce the air gap for more air, aim not so close for less air. 

[Smoggy]

Can you give details of the fan you'e made Alex, there may be away to improve it, also your supply to the tuyere as Glenn refers to may be restricting flow if you're now working at a lower pressure. Is it aside or bottom draft forge and what fuel are you using? Pictures are always useful if you can supply some.

 

 

[Alex w]

3 hours ago, Smoggy said:

Can you give details of the fan you'e made Alex, there may be away to improve it, also your supply to the tuyere as Glenn refers to may be restricting flow if you're now working at a lower pressure. Is it aside or bottom draft forge and what fuel are you using? Pictures are always useful if you can supply some.

 

 

I am using a bottom draft forge and using coal

[Daswulf]

A couple issues I can see. 1 your air inlet pipe is restricting as is, and will collect ash blocking it further. ( a T pipe will be way better for a bottom blast coal forge. Think of the T on its side the long part is your air inlet then one part goes up to your forge pot and the other is capped or better, put a weighted flap cap on it to collect and dump ash. ) 

2 the box on the fan is sort of a good idea but it doesn't efficiently direct the air to the pipe so you are barely even getting what the fan can produce. 

 

[Alex w]

Okay, how can I make the design more efficient because that’s all I have. 

3 hours ago, Daswulf said:

A couple issues I can see. 1 your air inlet pipe is restricting as is, and will collect ash blocking it further. ( a T pipe will be way better for a bottom blast coal forge. Think of the T on its side the long part is your air inlet then one part goes up to your forge pot and the other is capped or better, put a weighted flap cap on it to collect and dump ash. ) 

2 the box on the fan is sort of a good idea but it doesn't efficiently direct the air to the pipe so you are barely even getting what the fan can produce. 

 

 

[Daswulf]

Firstly, what kind of tools do you have at your disposal? 

Fixing/ replacing parts of it will vary weather you have a welder( or access to one or someone with one) or if you are going at it without one but atleast have some simple tools like a drill and 4-1/2" grinder or hacksaw. 

[Alex w]

I have a stick welder 2 angle grinders (one 4 1/2, one 9 inch) I just don’t have thick steel tubing to weld with because the thin tubing I have now will just melt

[ThomasPowers]

Do you have any wood or even cardboard and duct tape to make a pyramidal funnel in front of the fan box to direct the air into the pipe a bit better? Can you re do it to remove any of the right angle bends in the air flow? (How would you change it so water would flow better through it?  Air works the same way...)

[Alex w]

I am in the process of getting some tubing for it to flow better so I could re do it

[Daswulf]

Here is my T pipe. Mine is 2" black pipe but it could be square as well. This setup will give you a better air blast where ash won't accumulate and block airflow. 

You could cut an opening on the bottom of the elbow already attached to your pot and add an extension down as the ash dump then attach the blower to the angle off the side. If you can't weld it, the square pipe could be cut so that it could be sheet metal screwed together. 

Also what Thomas mentioned about the box for the fan will help as well. 

[Alex w]

Thank you for the idea

[Frosty]

Alex: All you're doing is directing air it does NOT need to be heavy steel, you can use plastic vacuum hose to a few inches from the fire as long as air if slowing it's golden. I make my tuyeres from truck exhaust pipe. 3" for the vertical and 2" for the horizontal to the blower. A simple sheet steel flange and it screws to the forge table and a screw clamp exhaust flap cap makes the ash dump.

I use my drill press and hole saws to make holes in the pipe and match the curve so welding it up is easy, everything matches exactly.

Stick around a while and you'll figure out I LOVE my hole saws.

Frosty The Lucky.

[Alex w]

Thank you this has helped me alot