Hi all, Wanted to provide an update on our testing of our gasifier. I'll give a couple of shout-outs here but I fear I'll miss some; if I miss you, I mean no offense!!
First off, here is a video of our Sept 13 run. As compared to our previous videos, our product gas appears to be much better quality than in our earlier efforts. http://www.youtube.com/watch?v=XBCzguKuJkI 1) Per Stephen Maupin and Doug Williams's suggestions, we redesigned our flare apparatus. We are sure it is NOT technically perfect, probably not even close, but that change certainly made a noticeable difference in the appearance of the flare. 2) Arnt Karlsen and Ted Carbone each get a big "thank you" for discussions regarding increasing the constriction at our reduction zone. While I was agonizing over the pain of trying to build a constriction into/upon the existing wall AND ALSO preserve our thermocouples, Ted pointed out that we could go the other way, from the center out. One heavy, large SS funnel, turned upside down, stuffed tightly full of Kaowool and simply resting on the grate and, there we go, smaller reduction zone. Saved our thermocouples and solved the question of how to create a mechanically stable and reasonably gas-tight restriction. Couple of observations: Our start-up time was significantly shortened after this change. Our reduction zone TC gave much more stable temp readings during steady-state (1500 - 1700F, 815-925C, depending on other conditions). And as a side note to several folk, with that change, under our best steady-state conditions, our oxidation zone is now reading hotter than our reduction zone. When the system is running very well, the oxidation zone will poke a bit over 2000F (1090C). Neither zone is yet hot enough, per advice from some of you on this board, but we are higher than previous and apparently now in proper order of higher heat to lower. But still work to do on this topic. 3) Apart from both this discussion board and off-line conversations, we also dug back into our library of gasification literature for a refresh and review of the old art. One monograph in particular, "Driving on Wood" (aka, "The Pegasus Unit") caught our attention. Chapter 11 of that book includes many sketch diagrams of WWII era systems. We realized that pretty much all of those sketches included some sort of a "bucket-of-wood" type of filter (or a first-cousin equivalent of that). We did not have that in our system. But we do now. That addition to our system made a notable improvement to our gas quality. Granted, that is post-gasification clean-up, but we'll take it. We know from math modeling and from empirical observations that we would like our air flow to be higher than it is, so we are still working on that challenge. We also know from studying our sequence of filters that we still have room for improvement on the overall gas clean-up. BUT, as can be seen in the most recent video, versus our earlier work, we've made some positive progress. And we offer our heartfelt thanks to all of you who offered suggestions and food for thought!! -brian _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org UNSUBSCRIBE HERE; http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
