Discussion in 'Burners and their construction' started by OMM, May 22, 2019.
Oh nooo....That's not CREEPY at all.....
That’s not creepy at all.... The creepy part is,...if you really want to think about it, we all here have or want a miniaturized crematories on our properties. Some might want to call them foundries or forges....
One of the, The head guys opinion was “we are just high-end Masonary guys. We’re just building a glorified oven”. I asked him “what is the difference” , he stated “afterburners with a second burn chamber , hearth burners with all the clocks and read outs. He stated that this furnace has a maximum capacity of 3 million BTU, at 2600°F at 1000 days plus, with little shock heating.
He specifically mentioned shock heating is anything less than 1000°F that is rapidly accelerated from less than, to above. He stated moisture should be chased out for 2 hours minimum. But above and beyond 1000°F you can go fulltilt.
I’ll probably replace the brick short life. The cast iron foundry I frequent, pours after six hours of heating.
The roof looks to be much worse than the walls. Talk about cracking, wow. Any idea how its constructed? The furnace isn't so creepy, but the worn transfer roller got my attention.
Maybe it's regulations or licensing requirements but......I'd say pack some plastic refractory in those cracks and carry on. I don't think the customers would care....
Yup.. Hair on the back of my neck sticking STRAIGHT UP!
Today I picked up the leftover brick (the new stuff)
I asked them if I could have the lighter ones. It is amazing the difference in weight.
The light ones = 3 pounds 11.9 ounces = 1.698 kg
The heavy ones = 6 pounds 15.8 ounces = 3.17 kg
Almost double the weight.
I only got 40. So now I need to start designing around that amount. I also got a roll of 2” fibre blanket (2’ by 12.5’).
The bricks I got have a 3500°F (I think by writing on the brick, correct me if I am wrong) rating and the fibre blanket 2300°F. He also gave me a half bucket of high temperature mortar. I guess it’s time to start building.
Shhhh...... I borrowed the wife’s scale. a little bit of silica Crystalline and sodium silicate never killed anyone???
get to work!
You got the right stuff and saved some serious cash. Nice haul.
Wow, you're all set. Nice!
Thanks guys and yes it is time to start building!
I am going to be building it very similar to the YouTuber Paul’s garage but 10 sided (Decagon, I will add a video below, sorry the video is torture). I will use the 2 inch thermal blanket to insulate the brick. I’m only going to use the mortar for the top brick, All other brick I am going to loose lay with somewhat of a hose clamp. The off cut from the top taper (he mortared together with a step to side walls). I think I’ll add this into the sides....
The top will have a 4” hole... and so will the bottom.
By my calculations, I should have 11.8” inside diameter, with 14” inside height.
I’ll start a new build thread.
Looking forward to your build thread. You're measurements sound pretty good.
It certainly would appear to be a 3500F designation. That's unusual but possible. In general, as the bricks become more dense, they are stronger and more refractory but less insulating. They also become harder to cut. Do the lighter weight bricks have markings too? Are the bricks 9" x 4.5" x 3" or less than 3" thick? Based upon density I was guessing around 2600F...but maybe higher if the bricks are thinner.
I realize that is tongue in cheek, but if you are going to use power equipment (Table saw, sander etc), I'd move them outside to perform the cutting and shaping. They will send fines into the air and coat everything in your shop and then become easily air borne in the future. Afterward, clean the saws and blow them off before moving them back inside. Besides the biohazard, the stuff is extremely abrasive and you'll want to remove it from the working surfaces of your equipment.
If you intend to hand shape with hand saw and abrasive blocking, I'd just keep it cleaned up as you go. Wear a respirator and change your clothes afterward......it's not worth it.
Which brick will you use? Have you tried cutting the high temp brick? The low temp stuff cuts like butter but high temp can require masonry saws.
Generally, you'd like to start with the highest refractory materials in the interior and then layers of the more insulating, lower refractory material as you build outward. Than can be inconvenient but you will have a steep temperature gradient across the wall and that's why the Mortar coated wool furnaces work.....the thin refractory layer is sufficient to lower the temperature for the much lower refractory wool behind it.
If you use the 3500F bricks for the inner furnace surface, it will have very high refractory but also much higher mass and that will mean higher fuel usage and time to temp for first melt. This is where you need to decide if you really need the high refractory material. If it's an iron furnace maybe, but the lower refractory brick with a layer of Satanite would probably do just fine, and be lower mass and good insulator......always trade offs.
I've done that deed. Had to add a couple grooves for heating elements in my case.
You can Mortar or not. There are some pros and cons. Mortared bricks have tight joints that wont leak hot gas. Unmortared allows replacement of single bricks if damaged.
Good luck on your build.
Would a relatively cheap diamond wet saw be the way to cut these dense bricks? I wouldnt put one across my dewalt, but would have no problem with a 200buck harbor freight shitter. https://www.harborfreight.com/7-in-15-hp-bridge-tile-saw-62382.html When you're done, you could craigslist it or take it back. Probably cheaper than renting a tile saw from hd.
I'm sure it would. I don't know at what point an Insulating Fire Brick becomes a Dense Fire Brick. 2300F IFB is usually around 35lb/ft3 and dense castable as high as 150lb/ft3.
All the IFB I've worked (2300F and 2600F) you can literally cut with a knife, a few strokes of a rasp or coarse sand paper. For dense high refractory materials I've always used castable so I can put it where I want it without cutting.
I've got some dense fire brick and shudder at the thought of cutting it. If it's anything like mizzou, mask up big time.
Yes, I've got a cheap Princessauto diamond blade for my 5" angle grinder and I've been really impressed with it. it cut fast and clean. If you plan get one, two things you need to know, make sure you get a segmented blade, ( the solid blades need to be water cooled) and the dust from these blades is nasty so get a GOOD dust protection respirator.
On site they cut them all with a wet sliding diamond blade saw. But they mentioned they also have 2800°F blocks that are a little lighter (less dense, Not on site back at the warehouse) than the 3500°F blocks. I only got one off cut of the really heavy stuff. I thought it would make for a good plinth. The bricks I got 40 of are 2 1/2 x 4 1/2 x 9“ The really dense ones he said had the same 3500°F rating. The visual difference for me is the colour. The light ones are white and the heavy ones are orange-ish.
The White bricks (or light) he said they they use the wet saw to cut to size and then they use a drywall keyhole saw to shape them.
The heavy one would make a good plinth if you don't cast a round one. If ya had a wet saw, you could knock the corners off it. You know maybe the wife wants a nice brick sidewalk for the side door? Good excuse to buy a wet saw. Remember cardboard or it will become a permanent part of your crucible!
I cut my IFB's with a dry saw outdoors, but only because I could not find my wet attachment.
You don't need the water on IFB's, but as Kelly mentioned, if you cut them dry, you get a lot of dust everywhere.
The dense bricks really need wet sawing else they tend to overheat the blade.
They make some long stainless hose clamps, ie: like 36" long, and you can connect them in series too if you need a longer clamp.
I use then with light tension around my IFB's, to give a little room for thermal expansion.
I use a 1" Mizzou hot face, but if I used 3,000 F IFB's, I would not mortar them, since that makes replacement difficult/impossible.
At most, I would use a tiny amount of high temp refractory (like Plastic A) to seal any cracks that may open up, but it would be very shallow, and would not prevent you from replacing any single IFB.
Also note that a furnace with a smooth circular interior surface seems to flow better, and for my IFB's, I used a cut-off disk in an angle grinder to dress the interior surface of my IFB's to get a round interior, and that worked well.
Note that dressing the IFB interior surface may change the angle of the cut on the sides slightly.
Here is an example of the interior of the IFB's dressed freehand.
You can get it pretty accurate if you pay attention.
You can also sand the interior of the assembled IFB's to smooth out any irregularities.
As you can see, curving the interior surface threw off the fit of the last brick, and there is a slight gap, but with a hot face, the gap does not matter.
Separate names with a comma.