we've found the manometer to be the most important gauge on a gasifier. the manometer is set up to measure pressure drop across the reactor. we use this to know how hard we are pulling the reactor and keep it in the no tar zone.
i propose this can be the equivalent of a speedometer for a gasifier. it is very easy to use. here's the summary numbers you want to see, in inches of h2o. 12+: Overpull 10: Maximum 8: OK 6: Good 5: Ideal 4: Good 2: OK 1: Minimum 0-1: Underpull these numbers are taken from the larger instruction set on How to Operate a Downdraft Gasifier. this is our attempt to come up with an easy "speedometer and tachometer" for a gasifier. no complicated science. just driving gauges. the full instructions are here: http://gekgasifier.pbworks.com/The-Masonic-Method%3A-How-to-Operate-a-Downdraft-Gasifier the excerpted part on using the manometer is here: ------------------------------------- Your Gasifier Speedometer (aka: the manometer) The most helpful gauge for informed gasifier driving is a manometer measuring the pressure drop across the reactor. The pressure drop across the reactor tells you to an approximation how fast you are pulling the reactor-- or in other words, how much gas you are making. For good results, you need to pull gas between the min and max gas rate acceptable for the gasifier hearth dimensions. Pulling too fast or too slow will create problems. -Pull too slow and you'll make a mess of tar. -Pull too fast and you'll make soot, weak gas, and ultimately clinkers. This min and max gas rate band is fairly narrow, thus the need for an experienced operator to find it. Fortunately we can quantify this "good band" and have the “newbie” read a gauge to approximate "expertise". Our tests have shown the min-max pull rate band as 2" to 10" of h2o vac across the reactor (before filtering). Stay within these limits and you'll have good results. For even better results, try to stay in the sweet spot,, which we consistently find to be 4-6"h2o vac range. You can push things up to about 12" and idle down to about 1", but you are tempting trouble at these extremes. Here's these "speedometer" manometer numbers as a chart. You might want to print these out and keep them with your gasifier. 12+: Overpull 10: Maximum 8: OK 6: Good 5: Ideal 4: Good 2: OK 1: Minimum 0-1: Underpull These values can be read manually via a simple manometer, or we can use the same values to inform idiot lights and electronic automation. In all these cases, the critical new learning here is that we can formalize the min-max rate, and make informed operating decisions in relation. We do not need to guess, nor do we need to rely on years spent face down in the black goo. These numbers assume a well configured gasifier with reasonable hearth geometry and nozzle sizing. We can get close to reasonable dimensions using the standard Imbert charts. For further refinement of these dimensions and configurations, see the tuning section below. Yes, different gasifier types, sizes and fuels will introduce some variations in this scale, but they are less than one would fear. Also, these variations can be quantified with the same formal system, and thus compared between machines. Refinements and addenda are expected to the above guidelines as others use it. here's my proposed numbers for what you should see. -- ------------------------------------------------------------------------------ Jim Mason Website: http://www.whatiamupto.com Current Projects: - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs - Shipyard Announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org
