Coalgun- Puff backs & Explosions

whistlenut wrote:I think that type of timer is on-off and repeatable. You need to be able to 'accumulate ten minutes of run time for the stoker motor, before you issue a command to run the ashing motor for 2 minutes. I will look over the specs in a few minutes, but you DO NOT want to have the stoker run 10 min, ash for two minutes all day. Only when the accumulated ten minutes occurs, then it runs for 2 minutes. The run time is KEY, because that will indicate the the appropriate ash has been created. It is not very scientific, but we are not t in the return trajectory planning stages.....only trying to safely burn black rocks to keep the family warm...and our workshops.....

You may be in luck, and trust me, all the rest is hocks-pocus. Combustion air needs a helping hand......purging itself. Fuel depth in the hopper is not the issue, as long as it does not run out.

Thanks Whistlenut! While you were typing this, I was adding more to my previous post, so please also go back and re-read it.

The LC unit has LED's for C degrees and F degrees, and my F (Fahrenheit) LED is glowing. The SV and hysteresis settings are correct as per Darren's instructions.

I'd say the unit only ashes about every 3rd or 4th time the fan cycles on for a thermostat heat call. It's hard to say how long my individual heat calls (fan cycles) run, since that is sometimes dependent on how many of my homes 4 zones are calling for heat at or near the same time, and that is dependent upon how cold it is outside. 15 to 17 minutes seems about right for a typical fan running cycle though.

Sometimes, when it does ash, it may ash for nearly the entire fan cycle, and sometimes it only ashes for a small fraction of a fan cycle (and everywhere inbetween). This being dependent upon the ash grate temperature.

As to ash accumulation, I'm getting about 28 lbs. of ash out for every 300 lbs. of coal going in. Ash accumulation over time and over feed lbs. added seems rather consistent (with the big difference being that I'm seeing half or less the ashes this season with UAE Harmony vs. last season with Blaschak). Size is pea, and both Harmony and Blaschak appear to have just about the same overall range of nugget sizes.

The last time I actually looked through the draft port door after a fan cut-off there was a nice orange glow to the burning coals.

When there is no wind assistance, my chimney draft tends to hold at a steady 0.03" of WC (in these weather conditions).

I just tossed 120 lbs. of coal into the hopper, topping it off. Time to see if my puff-backs return.

I have no way of knowing that my ash grate thermocouple is reading accurately. The only thing I can say is that the ashes that come out of my Coal Gun never seem to be very hot. I could probably go straight to a garbage bag with them (though I generally leave the ash bucket out for a couple hours to fully cool first, being cautious). I have two ash buckets that I alternate.

If I knew how to do it I guess could take the thermocouple probe out and place it into measured hot water to see what the LC unit reads.

No puff-backs following my loading it with 120 lbs. yesterday. That is down from the 160 lbs. that I had been feeding it. Either feeding it 120 lbs. or less is the key, or dropping the SV to 100 degrees is the key (or both were steps in the right direction).

Yanche wrote:The temperature sensor is a thermocouple sensor.  Type K.  There was one member that suggested that they are now using Type J, which has a narrower temperature range. 

By this do you mean greater precision for the J thermocouple?

Yanche, by what principle and mechanism does your older S130 ash? Is it as a percentage of fan running time? Are you experiencing any puff-backs?

I just had another puff-back. Ash level in the pan is substantially more now than it was earlier today, so my assumption is that sometime during the day it must have ashed long and hard and dropped the fire down low again. It seems as if ashing more predictably and more evenly in quantity over time (as opposed to temperature) would be of potential benefit.