Diesel Burner

 Since I built a larger furnace, I can still melt aluminium with propane, but bronze,not so much. So it was time for a diesel burner.

Based a lot on a youtube video: Building A Burner. Thanks to swdweeb for the video, and some additional help he gave me along the way.

* A power Supply

* A PWM Controller

* A fuel Pump

I used a Danfoss 2GPH 60 degree oil furnace nozzle, and drilled out some steel bar and tapped it to make a holder.

I have a 250watt blower for the air supply.

Some things I learned along the way. 

• The fuel pump needs more than 5 amps - my benchtop supply tops out at 5 amps, and it was not enough.
• The power supply and PWM are 30amp, because they are cheap, I think the pump runs about 8-10 amps, and I didn't want to be near the limit.
• The 2GPH is too much, at 30% pwm I am bounded by the air I can push in.
• The 40mm hole I left in the furnace for a propane burner is kinda small for diesel. I wish I had 60mm instead, then I could push more air at a lower speed.

I'm going to get a 1GPH nozzle with a 45degree solid spray pattern, and see how that works. It should allow me to turn down the furnace with a higher degree of control.

I'm going to shorten the air hose, to hopefully allow more air in.

The grey connector which joins the air hose to the burner tube is 3d printed PLA. The air blowing through it keeps it plenty cool, it does not melt. Because this is bent at an angle, my diesel run is just a straight hollow tube.

I welded up a trolley for all the electrics the fuel, the blower, etc. This keeps things tidy, and makes it a lot easier to set up for a melt. The grey box at the top is all the electrics, including a NVR stop switch - just in case.

I also need to try Cooking Oil. I can buy that for about half the price of diesel, and it might be fine for melting aluminium.

And some aluminium fell to the floor of the furnace while I was doing a melt. That aluminium never fully melted, it just got to that soft stage, so I think I will put in a taller plinth and move the crucible up higher in the chamber, the bottom is "cold".