The best of the best burners!

Impressive! Can you point me to the details of your burner and furnace?

 

College trys are encouraged here! Every new idea starts as a blasphemy.

Pete

 

My furnace information is somewhat outlined in this thread: http://forums.thehomefoundry.org/in...ats-of-satanite-to-high-temperature-wool.589/

But the summary is it is simply a 30 gallon barrel cut down some in height, lined with 2” of 2600 wool which is covered with a couple thin coats of Satanite. It started life with a poorly designed lid not well suited to the muffler I had to put on it. It now has a IFB modeled after yours and coated with bubble alumina. (Only three runs with the new lid so too soon to make many pronouncements about its durability—-so far so good.)

I use an A20 crucible on a now 5” plinth and a Hago siphon with 8 pounds fuel and a 20v leaf blower combustion air source.

I am pretty well convinced it is not some special design magic that made the furnace run well, but just better tuning. I used to take a more laissez faire approach and was less tuned in to some of the Ursula-related discussion about the importance of combustion location and plinth height than I feel I am now and also used to run too much compressed air. This “new knowledge” all gained from contributions by many here on this forum. For those bits of info I am most grateful. I will add a qualifying “I think” to all of this paragraph. I suspect that a somewhat heavier furnace of similar dimensions (especially the plinth elevation) would perform well. Maybe a bit slower, sure. But, I was especially careful this time to keep right on the jagged edge of just below oxidizing mix, turned down the compressed air to barely on (it actually registered zero on the gauge but it was on a little) as soon as combustion continued well.

The real test comes to see if the same good response happens next time. And, of course, next time will involve more metal as have most prior melts. So, direct comparisons of one melt to the next are difficult.

Denis

 

Thanks, Denis. Too many people here and I can't keep them straight. I remember your furnace and muffler stack. What a pain to have to put up with. But when you have to you have to.

You could sure cook some brass.

With 2" of wool does the drum metal get hot?

 

I'm all for the ol' college try. Remember this?

 

The drums heats to about 450F to 500 IIRC. So yes, quite hot.

Yes, the noise concern seems kinda weird. I mean I run for an hour or two if consecutive melts. Not that loud really unmuffled. But there is construction in the neighborhood nearly constantly. Someone just got a bee in her bonnet. Most surprisingly, I thought all was very cordial with the husband and I tried hard to keep it that way. Then the email... Oh well.

Denis

 

Buy them some ear plugs and tell them to piss off. My crapsman shopvac is louder than my furnace. Anyone complains about the noise coming off mine is getting stuffed IN IT.

 

I started to say that 4" of wool in a larger can would cool the can nicely but had second thoughts. With 500F on the outside you have significant heat loss through the insulation which is keeping the hot face a couple hundred degrees cooler. You might find that more insulation would dramatically decrease the hot face wool life. You're trying to melt metal not save fuel. Don't mess with what works.

Jason: I have a neighbor like you. And so does he...

 

To the guys that use drip burners. Are they really drip or are they more of a stream? Today I was testing my Kwiky (using water only) and with 12 inches of gravity I was getting a flow rate of 6 L per hour. It was a steady stream. When I turned on the combustible air it kind of went to a spader. I am using a four stage hi pressurized blower.

Can the guys using drip burners start with Diesel fuel, with a blowtorch?
Generally how do the guys that drip feed get their furnace up to temperature before they introduce motor oil?

 

I guess this is a bump.

Trying to keep the best of the best still alive...

Many thoughts are in the drip... to keep things simple. I agree after two hours of testing burning, and testing different elevations.

I had my best success (almost overload) with no siphon and about 4 feet of head pressure from gravity. About 1 L per minute Diesel and about 3/4 of a litre per minute with oil.

I am thinking that it is possible to use schedule 40 half-inch to deliver the air and fuel mixture. I think I might be able to deliver this from two separate burn tubes with a pretty simple design. I’ll test one first.

 

Knock yourself out man, I'm up to my neck in glass and welding work. I'm happy to watch.

 

Guys with drip burners like brute, hotshot, and moya are generally preheating with propane. The numbers you stated in your last post for fuel flow are much higher than you can use or afford. The fuel consumption you'll see here are more on the order of <1gal/hour up to about 3. Even with the right amount of air, the size and configuration of our furnaces limits how much combustion we can support. As for the half inch cumbustion air pipe, the amount of air needed to burn even 1 or 2 gal/hr would be moving too fast as Melterskelter mentioned in the Kwiky thread. You've gotten a lot accomplished on open air, but it seems like nows the time to get your rig in a furnace and see what will actually work in an enclosed environment.

Pete

 

Pete, we all want to see what a 16gph furnace looks like!

"Its not how fast you mow, it's how well you mow fast!" ~ John Deere

 

@Jason very true.

But 1 L per minute would be close to just over 13 gallons per hour and .75 L per minute would be just under 10 gallons per hour.

I did the Diesel/oil burn test at my cottage over the Canada day long weekend. The roar brought out a few neighbours for viewing.

With the back pressure with open burn, I melted the the little red handles and slightly deformed the lens of the pressure regulator. Live and learn.

 

1 L per minute X 60mins in an hour = 60liters an hour... 60/3.785= 15.85 GPH.

13 or 16, that's still a ton of fuel per hr to run through our little furnaces. When I tuned my Kwiky, I think I remember tuning for about 1.5gph. The motor oil I run is some used thick airplane crap. I have to warm it up a bit in the winter and still toss a little jet-A at it to help it move. Maybe if I tuned it for 2-3gph, it might move a little easier through a bigger hole?

 

My Oopsie. I was using the imperial gallon per hour not the US gallon

 

The US is the one with the screwed up system. Except I never wrapped my head around an Imperial gallon. You want a real mind screw... Try getting a call from an airport tower and they report winds in meters per second! Doing that math while fighting crosswinds and crazy gusting winds sucks big time.

 

I’m OK with meters per second, 28M/S is about 100 km an hour or 62 mph.
Some really get me. I don’t know how you keep them all straight.

 

Yeah, but these asshats will report it like this on short final....... Winds 230 degrees 8.5M/S gusting 11.7M/S. Now QUICK! WTF is that? Your crosswind limitation is 22kts and you are landing on runway 16. Legal or not? I just mash the rudder and if the nose still won't line up with centerline, I'm outta there.

I'd guess probably not due to the 80degree angle so this is probably over 22kts crosswind component.

 

A couple notes on running my siphon burner yesterday. I did a 50 pound melt of iron followed by a 25 pound melt burning diesel.

Instead of using the on-site 5hp vintage compressor (quiet and capable) I decided to see how well I could do melts using my little 109 dollar pancake compressor:
Bostitch BTFP02012 6 Gallon 150 PSI Oil-Free Compressor

I used just 8 pounds compressed air to warm up the furnace for 8 mins .of and then turned down to 2 pounds or so for the rest of the melt. Combustion air was provided by a repurposed “battery-powered” (I converted to a 20v DC power supply) leaf blower as is usual in my setup. Fuel is pressurized at 8 PSI by a common 12v fuel pump.

I poured the 50 pounds at 55 minutes from cold start at 2580 and the second melt of 30 pounds took 35 mins or so. The compressor was cycling on every 3 mins or so during the low pressure part of the run and maybe got 30 secs rest during the initial high pressure part of the melt. Even though my compressor is “quiet” by pancake standards, it is still annoyingly loud. So, if I am to use it in the future, it will be in a sound-deadening box. But, as far as delivering enough air, it did indeed.

Side note: the reason for testing it is I may need to move to a new location as the owner of my present borrowed location is suffering declining health. The nice old vintage compressor won’t be at the next location. Bummer!

I tried running the siphon for a while at near zero pressure but found the diesel was not getting adequately burned and started dripping out the bottom of the furnace. That’s problem might not exist for everyone as my nozzle is a ways back in my burn tube. If the nozzle were closer to the end, the fuel might flash better and burn ok with only combustion air.

Denis

PS. Happy 4th to my US neighbors and good day to the rest of you. ;-)