The concept Idea was; continious operation.
My first gasifeir project, Pascal's third, started with the goal to come to an automatic working gasifier that could meet the energy and heating needs of a complete autark home. For that purpose the build machine should be able to run 24 hours a day, seven on seven. The wish to Feed that gasifier with a simple feeder in a simple manor, not using sluises nor rotary valves, eliminated the Imbert's style types and made it a must to improve the open top gasifiers in such a way that our open top, unlike the previous open top's, known as tar makers, would be able to produce engine grade woodgas easy and comfortable.
The DriZzleR and the limits of that design.
With creative thinking good observation and a bit of luck a new type of gasifier was invented, equiped with a load depended level sensor, feeded in drip feed mode, "The DriZzleR"
Repeated operation, by different operators with independend builds, prooved that "The DriZzleR" is one of the very few, if not the only open top gasifier, that is able to produce engine grade gas without a much exstensive or poluting (scrubber) gas cleaning train behind it.
After a lot of testing, Pascal and I, are now able to produce with the DriZzleR and a VW 1.6l car engine, on pellets, 14 hours combined electricity and heating, and some 4 hours the same on woodchips. That is not bad and many would be happy with this results, but it is far from the goal we've set.
With a turning-grate, set on time interval, or presure drop sensing, the working time could be easy expanded, but that would be at the cost of, waisting a lot of valuable, not completely gassed out, charcoal.
On woodchips: even a turning grate would not be enough to run continously. Why? As I stated almost a year ago on this forum, minimum a grate sraper is needed too, to cope with the impurety's that are sneaking in with the chips.
Pascal and I Tested the past year almost dayly different fuels, delivered from various sources; The conclusion is that woodchips, having too many dirt in them, (stones, nails, bit of glass and ceramic and klinker), making it impossible to run the gasifier in a simple way continiously, unattented. A simple grate finger and a simple turning grate can not coop with a big nail that falls in the grate verticaly. More sofisticated and expensive automatic grate cleaning devises are needed.
The upsite down DriZzleR, grateless.
Trying to simplifice such complicated grates is one way to go. Going grateless is the other.
A good way to design a grateless gasifier is to turn the DriZzleR upside down. Have the open top as open bottom. Making the drip feed into a push feed. Fload the flaming pyrolyse zone with forced air.
Is a grateless non reduction gasifier revolutionary or something new?
Some of good people on the German Holz Gibt Gas forum are running already several years with good succes grateless and reductionless gasifiers. One of them is an gentleman named Pertl wich based his build on numerous patents, some already almost hundred years old. Grateless designs are nothing new, nor revolutionary, nor secret, lots of patents information.
Pertl produced with his grateless and reductionless design, from the begin of his build up to 8.2.2009 (after that he did not kept trac) 240.000 Kw warm water and 132.000 Kw electricity.
Another hard working succesfull gasser is, Holzigas, with the same VW 1.6L car engine as Pascal uses, He heats and energise his home already several thousend of hours, this from 2009 on; He has to replace his second hand VW engines regulary. (No sweat because in German they are death cheap. 50 to 100 euro's.
Seeing the concept could maybe solve the grate connected problems, we are tempted to explore also the posibility's of an upside down DriZzleR for continious operation.
What with the standard DriZzleR?.
Does that means we give up the regular DriZzleR. No way. This concept is so technicaly simple and elegant. It can be build by anybody without much pain. If you run it in intervals, some hours, then little cleaning, then some hours again, Just as most imbert types are run, it will produce the same good gas an easier way.
The DriZzleR will be further developed, It has a small but steady growing user comunity and news on it will be posted regualry. Side on side with the other new gasifier project The upside down DriZzleR.