Since I've been off work this past week, I pulled out the hopper (while under fire!
) and burned some more of the bitty from Valier's that I had on hand.
I think I'm done trying to burn this stuff in the DS1500. The bimetal t-stat just seems to react too slowly to control the amount of volatiles this Valier coal puts out. Even banking the coal, during the first hour of the burn, the stove top temp rockets up to 600+ degrees.
On Friday, I just topped off the fire with about 15 lbs of coal, and it was very windy, 40+ MPH gusts. I figured it was only a little coal, so why bother banking.... That was a mistake. I walked away and came back about 20 mins later and the fire was ROARING and the top of the stove was reading 760 degrees! My double wall stovepipe was pushing 300. I was getting a little nervous so I dialed back the underfire air, and turned the overfire back about 1/2 way (another mistake). About 5 minutes later, I had the worst puffback I've ever seen. It sounded like a bomb going off. There was smoke everywhere. Luckily it had just come out of the air vents, nothing was broken, and my stove pipe screws held.
Yesterday, I topped off with 20-25 lbs of bit, banking it. It went from a nice, stable burn, to raging. The stove top was flirting with 600 degrees again. I let the bitty burn down and today I put the hopper back in, and loaded up with good 'ole UAE Harmony anthracite.
I hate to throw in the towel, but I think I need to get a proper stove for bituminous. The DS Manual says not to exceed 600 degrees, and I'm kind of concerned about damaging my new stove. I would like a heat source for my garage, and I've been thinking of a warm morning 400 for out there, and sticking to anthracite in the house. I'm also open to other suggestions. As much as I like the looks of the antique stuff (i.e. florence hot blast), I'd like to keep costs in check.
*EDIT* - Sometimes I think I worry too much... I ran my old dutchwest in the 800-900 degree range on the coldest nights last year... In the early 1990s, on wood, I ran the thing so hot that the inside of the blower passages glowed red and the catalytic thermometor was maxed out at 1700F (dumb teenager!) Wouldn't dream of running those kind of temps now.