Great input and pictures Mr Pepe.
Have to say I’ve never seen this stout of hopper shaker bracketing. You’er not likely to crack and break with this.
Jim Mason does some wonderful expaining alright. All roads that lead to engine running with woodgas are Right.
On the fuel bridging problems.
Once past the fuel chunkiness mechanical locking up. Once past internal ledges hanging. I’ve still had problems going clear back to the very first gasifer I ever operated a very straight down into GEK II using just it’s tube-like straight in internal developer space without even using the external hopper tank.
Had bridging problems with even some of BepP’s earlier stuff.
Lots of shaker, even sideways bridging breaking up systems tried.
What I have personally seen was these bridges all had a componet of tars glueing to them. If the hearth was hard pulled to create a LOT of internal rising heat - bridging problem with the same fuels went away. As the gasifers advanced to hold in or recycle more heat back into themselves the bridging problems again with the same woodfuels went away. Got to where I could follow bridging problems based on the fuelwood moisture levels. Or the amount of fuelwood at the same moisture put into the same system.
That is where I came to evole the strong belief now that we need to balance out the gross amount of fuelwood moister AT ANY ONE TIME ALLOWED into the system to the available gasifier internal HEAT that be produced for the duration of that fuel load.
Have to keep those wood tars, hot, liquid, cooking and flowing downward.
Anymore as an operater of mostly other peoples gasifiers I operator “adjust” this fuel moisture loading to the actual gasifier hearth/engine loading.
I stopped believing the mantra of “make the fuel bin sized to convience”, “make the fuel hopped to match your wanted run times”. Yeah. Right. ONLY with perfect out of system kiln dried wood fuel or middle of the desert 1000 hour sun dried fuel m-a-yb-e. NOT what woodlands Rural living DOers actually have the majority of the year.
Try this on yours. Same wood fuel. Same wood fuel moisture. Pull your system up hotter making more heat by engine loading. Put in much less fuel wood. Batch by batch add more fuel wood to each batch until glue bridging begins. Now sun, woodstove, oven dry down this same amount of wood fuel and batch run again. BEST, yet; make the now loaded running engine heat do it’s own fuel wood drying for “free”.
I’m convinced. Only you can convince you. If you do become convinced you find this will drive forward you design principals.
My own personal system instead of now eleberate first lower hopper heating then upper condensate hooper converting the simple solution is to just use engine “wastes” heats to wonter wet better fuel wood moisture conditioning and not put these moistures into the hopper/gasifier in the first place and settle for shorted batch fuel cycles. Make the mositure load “foot” fit my gasifier “foot”.
Back to always needing an actual engine running for positive forward developement “benefits”.
In a not perfect world. With not perfect ingredents. With a not perfect oven. A Good Mom will still bake her kids cookies.
Hi Pepe; I think you will like your shaker. I noticed mine bridged after shutdown due to that one sq. ft. appx. area just sitting there cooking. Next day after cooling, I opened my hopper lid and started the shaker and after 10-20 seconds the whole center fell in filling the void. Remember not to shake during a run for more than 10-15 seconds every 10-15 minutes or so cuz the wood can pack together and block some air flow. But you.will get a feel for your own units operation. Very happy to see you getting to where you want to be. Dan
Hey Guys,
Thanks for comments and feed back.
Steve, Your info fits in well. I want to have several shorter runs anyway as it’s really time consuming to sit there and watch a full hopper burn away. I have seen the unburned fuel on the top peppered with creosote on the few times I shut down early in a burn, so I can imagine them gluing together especially at the next startup.
My first burn was 28 lbs and it went very well, no hop, skip or hesitating the entire burn.My second burn had about 50 lbs thinking a 2 hr run. It shut down real early in the burn. I’ll drop back to 40 lbs and try your suggestion.
As for engine exhaust I will use steel flex hose to direct the heat into my old copper cooler laid flat with some kind of cage over/around it to dry fuel. I’ll get there, man.
Dan, I used 1/4" plate for the top bolt on bracket plate, 3/16" angle (17" long) for the “legs” and 3/16" plate for the motor mount. I hope it isn’t too heavy. I’ve got a small pulley I’ll add some off center weight to. Any suggestions here? Thanks for the run time advice on the shaker. Compaction did cross my mind, but as I’ve said before, “crossing my mind is a short trip sometimes” lol.
You know, it just hit me that I totally forgot to manually shake my grate during either run, duh!
That trip’s getting shorter, Dan
Pepe
Yep! Seems we forget more than we remember as we age(ole to be young again with the knowledge and tools we have now). Bracket materials sound like a carbon copy of mine. I think I welded a piece of 1/4" flat eliptical piece to a steel pully maybe sticking out an inch or so from the shaft. Also a guard is a necessity as this offset spinning weight is very dangerous. Once operating properly with a timer you will not have to keep a constant eye on it. I actually went in the house and watched a 2 hr. movie and let the gasifier run on it’s own(it did fine). Looks like you have a 1725 rpm motor, thats good as 3600 rpm is too fast and the vibration cancels itself out. Dan
Thanks Dan, I was going to start with a small offset weight and see-feel how it worked. Glad I didn’t use my faster grinder motor- never thought about the smoothing out at higher rpm’s. I did notice your guard in your video. I’m also wondering what you used for a timer? Is it something from Radio Shack,etc? The off the shelf ones I looked at don’t have adjustable run time settings down to the seconds. You’re correct, running too long presents the problem of compaction and I’ve shot myself in the foot enuff already. Don’t want to be toeless!
Pepe.
Pepe, I am posting 3 pics. of my timer. If you type in the name and repeat cycle timer it should come up. I think it was about $60.00 on line. Can’t remember who I got it from. It’s a little touchy and the numbers sometimes don’t line up with the time wanted exactly but it works good and you just plug it in and plug your vibrator into it. Let me know if you can’t find it(if possible as I have not received any notifications from DOW in sometime ???) Hope the pics. help. Dan
The whole idea should be also not to waste ( whats in a word…)
Seen the good example from doing things the right way in the movie from Patrick Johnson…
Imagine you put a extra drum ( filled with fresh feed stock) beside your gasifier, rotating or not, blowing all the exhaust trough as an extra flu gas filter… extracting the air for your gasifier out of this drum as well (mixture of course)
If the drum would be rotating, that movement could be used to actuate the grate shaker…
As Steve pointed out so many times… use what you got any way… and i will ad : you need it any how…
My two cents…
@Dan and Pepe,
I know there are 2 directions the grate can shake, horizontal or vertical.
I am working on a solution for mine, but not quit sure which i should choose from…
(Thinking on using the starting relay from an electric Car starter to generate a vertical movement in my feedstock…)
I have a timer just like the one Dan has shown and they work great. If you are interested in running a DC set up here are the timers I use.
Timing will be determined by many factors, how hard your shaker hits and size weight and density of your fuel. My advice is be modest at first as a bridge is easier to fix than a clog.
Hi Koen,
I have a horizontal rotatable grate with 2" sides and 1" or so less diam than the shell (housing). It sits on a 3/4" threaded rod run up through the bottom. I use a pr of vise grips to rotate it. (when I remember). With the threaded rod this grate is shaken back and forth through about 45 or 50 degrees. If you keep rotating mine in one direction it will move out of “adjustment” (imbert design dimensions on chart).
I haven’t seen a vertical shaker yet. I’m not sure I like the vertical movement for no particular reason though.
. The starter relay sounds like a good idea, but will it pull the fully loaded grate back to the starting point? I’m not sure if this is what you meant to use it for. A ratcheting system could work kicking it around x degrees per shot. A little more complex, I think. I’m doing the manual for now (see pics), but Dan Cox has a neat motor driven rotating grate, check out his posts here and his youtube vids, very informative, well thought out, diligently pursued and interestingly presented with some candid humor.
Pic 1 General build info
Pic 2 Wrench on welded on nut rotates grate
Pic 3 Size of grate, about 3/4" space around it. Attachment plate too large, see pic 4
Pic 4 Hot gas flowing down through fire tube cannot use that portion of the glowing char above that large plate and a cool cone develops there and little or no reduction takes place there.Heat loss and less reduced gas equals lower quality gas. This is also my intro to internal leaks as I only spot welded the fire tube to its flange and gas was sucked around the tube by passing the reduction zone all together further reducing the quality of the gas. The flare had a lot of orange in it, compared to my present almost colorless gas.
Note also in Pic 4 that the firetube support flange is welded in and the firetube flange is gasketed and bolted to prevent gas by passing the reduction zone. Don’t skip this step, it’s a bear to tear down to do this after your gas doesn’t flare or burns smoky or has a moisture plume present in the flare.
The nozzles were 1/4’ holes drilled in plugs, not as shown.
Pic 5 I reduced the area affected by the support rod. Next time I will use four 1/4" x 3/4" x 5" arms welded to the rod to support the grate to further promote flow through the system. The new grate profile is supposed to help prevent clogging through better flow path.Exposes a lot of char edges to hot gas flow… less prone to plugging than the small grid screen. Semi self clearing.
One more note, the grate height is adjustable for operating experimentation. I haven’t tried this yet. My gas is burning real clean so I’m not going to mess with this adjustment.
These are part of my 75% operator’s learning curve.
Hope this helps. Pepe
Matt, Thanks for the feed back on the timer, I’ll check it out. So far that gasket material seems to be working ok.
Hi Guys
In theme with this fuel bridging problem phenomena here is a video by New Zealander Steven Amptramp back in April this year on his first operating his largish VictoryGasWorks “Woody” model gasifier on an unloaded 13 hp single cylinder engine:
He is reaching the correct conclusions that he is underdrawing this large 4 cylinder engine capable sized gasifer. He can’t make this gasifier smaller. I think his Radia Pine wood will be fine once he figures out to irregular side chunk it up to prevent flat on flat chunk stacking.
His only solution past increased engine loading to increase the gasifer internal heat WILL be to shake it.
He sure could use this DanC style bracket shaker with a DC starter motor mounted to it. (He’s dedicated off-grid since 1996.) EASY to make a DC starter spin out of balance counter weighting at the drive gear assembly. And they were designed for intermittent operation anyhow.
A comment on his youtube CNCmachiningisfun channel video back to this thread topic would be nice. Google owned now YouTube will not play nice with my yahoo address and any longer allow me post comments - barely lets me even watch anymore.
Hey Pepe like your newer grate grid. Up-bumping on a grate with some of the hard, hard, wood chars like oak and hickory can be beneficial to fracture the lumps for more new reactive edgesexposure .
Always a mistake though with soft, soft wood chars like pine and others as is will crumble them up and the gasses flow clog at the grate.
Hi Steve; Yes this google yahoo thing is a pita, it stopped me from commenting(coincidentaly to Steve)unless I accepted google plus. I did accept g. plus and was very unhappy with it’s prying and demanding ways. So I went to help and found out how to delete g. plus and did it. My youtube account seems to be working better now. Lots of folks unhappy with these forced upon us changes. Also agree,you have to keep it hot! Dan
Hi All,
Dan, I thought you said I would like my new vibrator? I love it, man, thanks for your vids, they are great teaching tools from one of the most determined gassers I know.
Here’s a vid of my last run, my best engine run yet. Next up is a new filter system. I noticed I forgot the 2 outer bolts on my motor mount, that’s the vib heard in the vid. I also didn’t pound in the milk can cover all the way so I got an air leak. Maybe that contributed to my lower temps, but still a great run. I also noticed that my air adjustment was on the lean side from my previous run. I saw some comments about this here recently. All interesting 75% tidbits.
Enjoy, Pepe
Sorry, Video got deleted by accident on You Tube. I’ll work on reconstructing it.
Pepe
I knew you would like it as it shakes the daylights out of the whole unit. I hardly ever use my grate turner anymore as the vibrator not only shakes the hopper, it shakes the grate too. kill two birds with one stone. Your small engine is not going to keep the heat high enough for Tar elimination(at least I do not think so).You need to get a thermocouple and check the tenps. in the restriction area.Try to get and keep at or above 2000°F. No tar can survive that.Soon that thing will be running itself. Have fun, Dan P.S. Thanks for compliments!
Hi Dan, The 8 hp is the only engine I had ready to run. I have a twin cylinder 18 HP B&S engine on a rider that will be next up as soon as I check it out on gasoline. My 4 cylinder IH Cub tractor has only about 10 - 11 HP, totally surprised me considering it easily pulls a 12" plow. Is your thermocouple permanently installed and what brand, etc is it?
Thanks, Pepe
Pepe; The only sure way to know for sure is to check temps… My thermocouple is NOT permanently installed. I just check once in a while until you get the feel of your unit. Once you get use to it and run it on the same size and type of wood on a regular basis, you will only check it now and then. I am posting three pics for you. just go on line with the info in the pics and you should be able to find them. I think the thermocouple was 20-30 dollars and the pyrometer(meter) was appx.60 dollars. If you don’t have a port to reach the restriction hole, you will have to make one. First two pics are labels on thermocouple package tube and the third pic is the actual pyrometer. I’m proud of your successful hard work, keep it up. Dan
Hi Dan, Thanks for the compliment and information. It’s certainly nice to have a trusted source that we consult with. My neighbor has a 1966 or so 4 wd scout with a 4 cyl low rpm high torque engine that I can have for “scientific purposes”. 152 cc, 92 HP. I haven’t taken a good look at it yet, but will today. I don’t have a lot of time or bucks to rebuild anything.
Pepe
Hi Pepe; Just watched your newest video. I can’t respond to comments on youtube now because I deleted Google SUCKS(plus) because they are very intrusive on putting photos and more out there weather we like it or not. Anyways, Your 18 h.p. engine may be fine. You will be able to tell when you can check your temps. with a thermocouple. In an emergency you could do like I did in my log splitter video and siphon off gas from flare tube to run smaller engines. You waste a little gas that way but you keep the temps. up with the vacuum and keep the Tars out and keep your small engines running. Dan
With my GEK gasifier and the Pyrocoil GEK Wiki / Tower of Total Thermal Integration option I can run my generator with as little as a 700 watt load and still maintain enough heat. The heat from the exhaust is used to heat the upper section of the gasifier. This is supposed to char the wood chips also but the generator I am using ATM is a marine generator with a water cooled exhaust manifold. So there is not as much heat available as there could be (it is only the manifold outer jacket that is being cooled, the water is not being put into the exhaust as it would in a boat).
With this set up I only get a very small area in the auger that gets any sticky tar build up and after about 70 hours running it is a small area only around 3 MM thick.
Hey Guys,
Gary, thanks for the info and comment, that is one neat looking set up.
Dan, I like the idea of pulling gas off like you mentioned, now if I could only find that one way valve I “had”! I’m going to play with the rider here, real soon, yeah!
Rather than try to put the puffer back in my movie I’ve made a short clip (15 sec ) and here’s the link to it.
