1 reply to this topic

[wilson0019]

Hi all,

We had run our gasifier a couple of times. Last time when we ran it, we found the Tbred was much higher than Ttred, which is definitely not normal. The Tbred was tend to be higher than Ttred and both readings were above 1000C.

We had a discussion about this issue, and suspected if there would be some leakings around the combustion zone, or probably because we ran out off woodchips (we didn't use the 10gal hopper, instead, we just fed the drying bucket and sealed it with a steel lid), also, our another suspicion was if we used up all charcoals laid at the bottom of reduction bell (we never added any more charcoals before running and last time before running, we dragged some charcoal out).

I was wondering if we need to add some charcoals every time before running? How much we need to fill? We are using the 10 kW GEK Power Pallet.

BTW, we kept the readings of pressure on GCU display at the range of -30 ~ -60, I wonder if that reading equals 3" ~6" water in manometer?

Thank you all, let's enjoy our gasifiering

Wilson

[JayAlchemAPL]

Hi Wilson,

Your mentioning of the possibility of leaks may or may not be your issue, however its worth checking off the list. Because the GEK operates under a vacuum, if there are any leaks then air will leak into the system. This can cause localized combustion in that area. However this may only be the case if you have a large gap that air is able to enter. When you shut the GEK down, do you see any smoke seeping out any potential unsealed flanges or connections?

I believe that the above may not actually be your issue especially because you have readings in the 1000C range. This means that you have combustion, not partial combustion (gasification) occurring. As you run out of wood chips, your fuel to air ratio changes. Think of it this way: the design of the gasifier allows air into the reactor only at the anemic ratio for gasification --when the reactor is full of feedstock.  as you run out of feed stock, the volume of your fuel decreases and the air let into the reactor proportional to the available feed stock increases to the point that combustion starts occurring. The temperature increases as less energy goes to crack tars and support pyrolysis with the incoming feedstock.

running the reactor out of feedstock can also go on to have combustion in the cyclone and even the gas filter.


the charcoal added to the reactor is only for the first run. After the first run, come back the next day and open the top, you will see charcoal to the top of the lid from the previous run (though sometimes you may need to top it off with more charcoal but not usually). You layer the charcoal and chips in the reactor the first time to mimic what the reactor experiences within a snapshot during the run. This ensures that it will start up quickly.

yes the pressure readings you are seeing on the GCU are correct.

Keep us updated with your next run!