Sunday, February 1, 2015

The Foundry: Testing Everything and Pressure Tank Disaster

Alright no more messing around, time to fire up the foundry for real this time with the new burner, new oil tank, and blower.
First filtering the oil with a metal screen and funnel I made from a coffee can with a pipe floor flange bolted on the bottom.  This just screws onto the pipe welded on the tank for minimum leakage.  I say minimum because it still leaked, which is why the towel is there.
filtering oil with screen and funnel
Reconfiguring the burner with the new needle valve.
assembling burner with needle valve
I welded a pipe to formally attach the blower to the furnace, the burner fits through the pipe.
burner mounted in blower tube
All set up.
foundry set up with pressure tank, blower, and burner
Firing it up. The blower made a massive difference in the performance as I could turn the oil up more.  Also, I was able to run it with the lid closed because there was enough air.  Flames were coming out of the top, bottom, and around the lid.  It was probably the hottest it ever burned.  I was trying not to melt my face off while adjusting the oil valve because the heat was so intense.  One of my concerns was the blower motor overheating again, but the melt went so fast that I don't think it got a chance to.
lighting the furnace
Due to the intense heat coming out of the bottom of the furnace, the oil line busted a hole and unleashed a shower of oil everywhere.  To add to that, it seems the regulator on the oil tank wasn't working properly and the oil had been pressurized far more than I expected.  I kept turning it up waiting for the needle to read 5 PSI, but it never went up at all! I have terrible luck with pressure gauges.
oil line hole
Yeah, I think that was more than 5 PSI, more like lim. n→90PSI. 
oil leaked everywhere
To make matters worse, I couldn't even stop the leak right away since I had put the oil shutoff valve on the burner instead of the tank.  Also when I went to turn off the air, the regulator fell apart.  Next time I'll know not to trust a regulator from a trash picked air compressor.
pressure tank problems
Despite the tragic outcome, the metal did melt, (along with the furnace wheels).  The ingot tray was in the splash zone, but I didn't care and just poured the metal anyways.  The oil instantly ignited and the molten metal appeared to be on fire, it looked like something out of the Terminator series.  I didn't feel brave enough to try using the soap dish mold this time, it too was covered in oil, and I didn't even get a chance to preheat it.
ingot spill
We had a fun time cleaning up the oil with some sawdust, though I felt bad about spilling oil all over such pristine cement.  We thought it was funny how the tools that got rained on left such clean outlines.
oil devastation
It looks like the oil pan did its job in collecting the oil that dripped from the furnace, at least there's one leak that was prevented.  This oil stayed lit for quite a while afterwards.
oil pan on fire
Here is how the burner fit into the blower air pipe.  I think I will extend the oil input farther back so it won't be as close to the heat, and also so I can adjust the valve without melting my face.
burner mounted in blower tube view
I felt rather disenchanted after this session, seeing how pretty much everything went wrong at the same time.  However, everything also went right: the blower worked, the burner performed better than ever with the new valve, and we set a new record for melting time.  By the end of the day, I already had an idea to solve the pressure tank dilemma, and that is to pressurize the tank with a bike pump.  Hope is not lost, the end is the beginning, we're just getting started.

CONTINUE TO PART 10 -- Oil Tank Redemption

BACK TO PART 8 -- Building New Oil Tank

BACK TO THE FOUNDRY MAIN PAGE

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