Hi all, If you really want to dry something cheap use a greenhouse. See this technology http://www.parkson.com/products/thermo-system . Bruce Green
On Sat, Apr 14, 2012 at 2:25 PM, Luke Gardner <[email protected]> wrote: > Greg, > I like it, there is certainly more than one way to skin a cat. > I was leaning toward auguring up and out of a receiving hopper to a very > slow moving and long declined trommel that has sections of screen to drop > the fines out early on, and have airflow (salvaged heat) blown through the > trommel opposite the flow of the wood to carry the moisture away. > I would agree that the passive approach takes about a full day of good > solar... 10 hours if the layer is thin enough. > I found by scattering them on a tarp (for easy collection) that the top > surface nearly "flashes" off dry very quickly. and then some hours later > in good summer sun, if you pick a chip up it is dry on top and there will > be condensation hanging out below it on the tarp, and its back will still > be wet. It's like they beg to be flipped over and placed somewhere else. > I believe that with minimal agitation (slow tumbling) in a thin migrating > stream they could be dried rather quickly. > anyone? > Luke > > > > -----Original Message----- From: Greg Manning > Sent: Saturday, April 14, 2012 5:23 AM > > To: Discussion of biomass pyrolysis and gasification > Subject: Re: [Gasification] Wood Chip classificaton > > Good Morning All. > > This is getting interesting. > > > I spoke with Pete a while back about this, and need to correct a > statement I made to him. > > "correction the fines (under 3/16" bits) do need to be sifted out" > this was about a statement I made to him on the phone, about this > thread. > > As far as drying wood chips, 3 things I have found are: > > 1) Sifting the fines before storage (even green) does promote faster > drying (this is relative as they still take a long time to dry). > > 2) The "top" about the first 2-3 inch layer of chips in a screened bin > dry quite quickly (days) where as the stuff at the bottom NO drying > action has taken place. > > 3) Removal of that "top layer" of dry chips to another area does > indeed cause the next 3-4" layer to dry quickly as well, and so on if > removed, as they dry. > > I've studied this problem in depth, and have a somewhat simple > (ya-right) method of drying. > > Sun, I'm in the process of designing a "sun lift", where as chips are > augured to an inclined day lift, the lift consists of a wide belt (48 > inches) that is inclined on just slightly less than the angle of > repose for the chips (about 30 degrees from horizontal), AND/OR, has > ledges that a small thin layer of chips rest on. This lift is some 12 > feet tall, and once the chips reach the top they are captured in a > covered trough that connects to a chute that sends them to a second > storage area. > > Here's the thing, the lift is rain protected, and has a sheet of clear > glass or plexiglass covering the area exposed to the sun. > > The process ONLY runs during warm sunny days, and at that, the chips > entering the bottom take the entire day (10 hours) to reach the top. > > using a light meter sensor that only triggers the units operation once > the sun gets to "X" brightness (cloudy days would not trigger the > unit). > > Preliminary findings are that sample configurations of chips sitting > as a thin layer on a sheet of plywood (with the 30 degree inclination) > take about 6-7 hours to be "bone dry" in the sun with a small flow of > air from the base upwards (chimney effect) I simply used a couple of > 2x6's on the sides to support a plexiglass cover and a bathroom > exhaust fan to provide the airflow. > > This was a test "mock-up" to simulate the slow moving "belt" system I > am thinking of. > > the chips that where placed on the board in the morning where 45+% > moisture green, a the end of the 7 hours, they where very "crisp" to > the touch, and snapped with a loud "crack" (indication of being very > dry) when pinched sideways, tested end of cycle moisture was under > 13-15%. the layer was rough, but for the most part, I would say 2-1/2 > inches thick. > extrapolation of the cost to do this is based on the following: > > 1/4 HP electric motor running for 10 hours a day at 10 cents a > kilowatt (I pay less than that, but know that some areas pay more) MY > sample motor under load uses 2.5 amps to work, therefore 2.5amps times > 115 volts equals 288 watts/hour (VA's close enough) so say 4 hours > costs 10 cents or 25 cents a day, times 31 equals $ 7.75 a month ( > I've rounded up on the costs, as to cover the cost of the bathroom > vent fan also). > > Because the system runs so slowly the 1/4 hp motor (through two 60:1 > reduction units one feeding the other) should develop enough torque to > run the belt and in-feed auger both. the output is gravity and I make > the assumption that someone would check on the unit at least once > every 2 days. > > Greg Manning > > ______________________________**_________________ > Gasification mailing list > > to Send a Message to the list, use the email address > Gasification@bioenergylists.**org <[email protected]> > > to UNSUBSCRIBE or Change your List Settings use the web page > http://lists.bioenergylists.**org/mailman/listinfo/**gasification_lists.** > bioenergylists.org<http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org> > > for more Gasifiers, News and Information see our web site: > http://gasifiers.**bioenergylists.org/<http://gasifiers.bioenergylists.org/> > > ______________________________**_________________ > Gasification mailing list > > to Send a Message to the list, use the email address > Gasification@bioenergylists.**org <[email protected]> > > to UNSUBSCRIBE or Change your List Settings use the web page > http://lists.bioenergylists.**org/mailman/listinfo/**gasification_lists.** > bioenergylists.org<http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org> > > for more Gasifiers, News and Information see our web site: > http://gasifiers.**bioenergylists.org/<http://gasifiers.bioenergylists.org/> >
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