Thank you guys for your positive comments about the Arduino datalogger upgrade. I intend to add a page of notes about some of the things I have learned “the hard way” along the line. I am not a C+ programmer, so I have written a lot of work-around code to get to where I need to be. The one comment I’ll make here: I see no need to use the Frescale MPXV7002DP pressure sensor in a gasifier monitoring system. The MPXV7007DP can easily read down to =/- 1/8" water column (about 32 pascals) so it can handle any “low suction”/“low pressure” situation you are likely to encounter with a gasifier.
Regarding Steve’s in depth reply: I have read it carefully and have assimilated as much of the info as I could. Here below, I take the whole commentary apart and address each issue. Thanks again, Steve. As you will see I found several actionable tasks to perform.
For reference: Steve has been viewing one of the videos on my youtube channel. The channel Is: http://www.youtube.com/feed/?frenchcreekvalley
Steve comment 1.:
Take heart. Tells you this basic hearth system can produce this amount of woodgas energy in that time frame.
He quotes 1-2 hours in hopper time on hardwood chips.
****Pete Reply 1: Yes, Tom Diesel and I have been talking for some time now. I agree with you. I will definetely convert the JXQ-10 to an imbert design like Tom has. Note, though, that Tom told me recently that he is going to build a WK type gasifier one of these days. (Right, Tom?) One of the reasons that I continue to work with the current system is to try to understand the dynamics of the thing completely. ----And to “get my feet wet”.
Steve comment 2.:
See his diagram and realize with his internal consticted hearth “Imbert” modifications he lost approx. 1/2 of his fuel capacity space above the grate. Chipped fuels in the same woods are always less dense tha chunked form. Bucket weigh them - you will see.
****Pete Reply 2: Yes, I always weigh everything. Without imbert-style nozzles, I can’t run chunks at all. I am always on the lookout for thicker wood chips, but so far, they are hard to find and most people who have wood chippers tell me that they really aren’t interested in the thickness; they just want to get them into the truck as fast as possible. Except for Greg Manning, who has been able to produce thicker chips.
Steve Comment 3:
So unmodified you should be able to get maybe 3-4 hours per internal hopper load.
******Pete Reply 3: My wood chips weigh about 10 pounds net per 5 gallon pail (4.54545 Kg/18.92705 liter pail). I can get a couple of them in there at once if I try hard. I usually figure fairly dry wood at about 9,000 btu/pound, so there’s gross the limit of heat on one loading. But, the way the gasifier works right now, it doesn’t matter at all whether the cover is open or not. I can add fuel any time.
Steve comment 4:
In your Putt-Putt video you observe the fresh fuel/still cold “Ram-jet” flare pressure pulsing clear back to the bottom of the grate. This is actually good for grate and char bed ash clearing. Once you go to loaded single cylinder engine running this will really help down out there too.
*****Pete Reply 4: Okay.
Steve comment 5:
You could see from your system pressure and flow obsevations that your system at 1 1/2 hour was gasses flow choking.
****Pete Reply 5: Yes, That’s where I decided that I need some sort of grate shaker, but, as you all can tell, I haven’t added one yet.
Steve comment 6:
Your blower motor sound change said this too. “I think” this was due to ash clogging in the grate/char bed area. Easy to prove. You have this mounted on inflated rubber wheels - get this happening again and with gloves give the whole hearth a good shaking. If ash flow cogging, you will see an immediate change in the flare or engine running performace.
****Pete Reply 6:This is a really good idea. Why didn’t I think of that?
Steve comment 7:
Your poker experience showed it was not a hopper fuel chunk bridging problem - no blower fan sound change - no flare change.
No changes with the system shaking - you will still be system flow clogged. These have an extremely small internal filtering chamber compartments. Really just like the small lower ash space designed to fuelgas supply the cooking stove for only ~2 hours at a time. Then cool down/ clean out for the next time.
Next time you observe system flow restiction if after the hearth shaking does not clear it - turn off your suction blower/turn off your engine, open the hopper cover to pressure and smoke vent and hot gloved hand pullout all of the filtering material. Close it all back up and try again without any filtering material at all just for a look-see, try-it, to prove it was NOT the flow area problem.
Soon as you do start power loaded engine running the much stronger gas pulling engine will be finally really heating up your system good, quick and claener versus the weaker stove suppling blower system. Your fuel consumption will min 2X, leaving 2X the wood ash to have to flow down and char surface clear and collect, separate out.
Sigh. Still a system flow clogged once you rule out ash and filter media clogging then it has always proven traced back to someone who was NOT been water wash system suppling and clogged up the internal baffling chambers and even the blower fan area with unwash down and out, now pulled through ash and soot drop outs.
Pete Reply 7: At one point in this test series, I forgot to check the fiberglass filter material that I had put in the output chamber. (Instructions say to use corn cobs or “activated” charcoal. Anyway, I found the fiberglass had turned into a black, gooey lump. Not sure what that situation was like at the time of the “putt-putt” test.
Steve comment 8:
These operator details are all actually JKQ-10 gasifier specific. I’ll leave it up to you if you want me to continue here on your thread “how to make it work for 10 hours for me” or you contact me directly through my membership page here on the DOW.
Area fellow here was statisfied with his “China Stove” set-up I advised in once up to a 6 hour engine run system. He could have done much better for run time, and responsibility. He’s very remote mountain and I was not very happy with his uphill creek in, to down hill creek water out, gas wash/cooling system. That creek runs into a Fed and State monitored protected salmon and steelhead trout spawning river. Easy solved with a couple of opened topped 55 gallon hopper/cooling/ash/soot settling out water cooling barrels and a 12 volt mini-pump.
Plus . . his local “grow” income source made me want to kinnda back out at earliest polite possible.
Pete reply 9: I use fresh cooling water into the left hand tank on my gasifier’s filter system. That water NEVER contacts the gas. But, as you say, this could be accomplished with a closed loop cooling system. As you probably know, Tom Diesel has already done this. He has 2 “radiators” on his system to handle this. I evaporate my “dirty water” and toss it out with the garbage.
Steve comment 9:
Pete there is something wrong with how you are picking up your “above” and “below” temperasture readings. Grate? From your Putt-Putt video you are getting good properly glowing hot down there with the pictured glow and your lower outer hearth paint color changes. My APL/GEK supplied probe always gives me min 1700-2000F (1000-1050C) above to 1400-1500F (800-850C) below on a properly drawn system. Is the thick poured in place refractory core in your hearth interfering with your temp picked up readings? It would be very hard to measure just what is happening with the temperatures moderated and redistributed out on the outside of all of that thermal mass.
Pete Reply 9: An excellent point!!! Another “why didn’t I think of that?”. And---- I REALLY should know better! I have made up many many thermocouples over the years, but I bought these SS, sheathed T/Cs on Ebay. I have calibrated my own homemade T/C’s, but not the ones I bought, assuming they’d be close. But, you are right. I have always been a little suspicious of the actual materials in use. Just because they say “Type K”, they might not even be Chromal/Alumel… I will definitely run calibrations on them. These sheathed T/C’s only stick 4 inches into the reactor area, but that IS enough to get them to the “red hot” zone above the grate, and into the hot gas stream below the grate.
I have been in contact with Kevin Chisholm, the Stak Properties folks and others JXQ-10 owners about this whole system. We seem to have concluded that there are many subtle differences (and some not-so-subtle) between various mfrs of the JXQ-10. It has been very frustrating to see that obervations that I make may or may not relate to the experiences of others.
End of comments.
Pete Stanaitis
