Hi, do you have a automatic feeder or do you fill it each time?
4-5 hrs runtime is about what i like to do also.
What kind of updraft is your setup?
3 Likes
Hi Roger , mine is a typical simple fire updraft charcoal unit , apart from the nozzle is vertically positioned in the bottom of a 205 L / 55 gal drum once filled to the top it will last anywhere around the 5 hours mark maybe a bit less if i am really pulling a lot of power from my 7 KVA inverter generator .
The nozzle is a tungsten carbide type tube i put in maybe 4 years ago and is now i think , its now starting to show some wear after these years running 99% of the time with no water drip or exhaust return to cool it down
If i needed to extend the run time its as simple as un clipping the lid on the gasifier and throwing in more charcoal , placing lid back on and pulling any air out of the system and re starting the generator for another 4 or 5 hours
Dave
10 Likes
Dave you canât get any simpler then what you are doing. It is totally a KISS gasifier system you have going for power off grid.
Bob
7 Likes
Well Bob i have so many ideaâs and designs in my head i have wanted to try out , maybe improve some , but after i think its somewhere like 12 years now this set up just works plain and simple so why should i re invent the wheel i know its flaws and it is so predictable it may as well be running on regular fuel as i just hear a slight note change and i know its time to do something .
Dave
11 Likes
Hoping for 15kw continous power from the B20 Volvo engine, but ill start low and work my way up, its no problem to use a 20kw asynkron motor and just not push it so hard.
Heat buildup is what i think is the largest problem.
If i can build it KISS style i would love that.
3 Likes
15kw continuous is certainly possible, but make sure you do the math on volumetric fuel consumption for your targeted output before you commit to it.
The experienced folks around here will quickly point out the limiting factor is mostly about fuel production and processing, not gasifier design.
All things are not equal, but using a 55 gallon drum charcoal gasifier as an example, (with modest quality charcoal and modest engine efficiency), you probably have around 10kw hours available per filling.
Getting 15kw output from it is just a nozzle size adjustment, but you will have a 40 minute run time between 30 gallon fill ups.
4 Likes
Not entirely convertible but in terms of my pickup that ran on an updraft, I used a 55 gallon drum as the vessel and would get roughly 60~70 miles per fill up. It being about 80HP on gasoline, I would suspect it derated at best to 60HP(optimistic guess). I had the acceleration of a classic VW Beetle and had to keep it above 2000 RPM to maintain speed and not be hampered by terrain but it did best at 3000 RPM, just past the peak torque but it measures peak HP at 5000. Top speed I made was 55mph without going crazy.
That all being said I think at 15kw or 20kw I would guess youâd have a runtime of 2 hours, conservative guess if you used my 2 Liter 4 Cylinder as a benchmark.
4 Likes
It is very difficult to find a baseline with these things because of all the variables.
The numbers I used are pessimistic because I have a primitive system, but they are actually what Iâve measured so they might be useful to establish bounds on what is likely.
My data:
Charcoal- 1.33 lbs/ gallon, softwood, hot/direct char making process, probably 15% moisture content, at 3/4 minus grind (undoubtedly low energy charcoal)
Engine- unmodified air cooled Honda clone, 196cc, 3600 rpm (pretty much the worst engine setup you could find unless you used a flat head)
Gasifier- single nozzle updraft, high velocity, slagging, well insulated (probably fairly high conversion rate)
Output- 10kw hours, 33 gallons, 3.3 gallons/kwhr (2kg/kwhr)
Not exactly cutting edge, as the literature suggests an expected range of .7-1.3kg/kwhr electric for charcoal. For example;
âAppropriate gasifier systems with internal combustion engines can produce 1 kWh of electricity from 1.1 â 1.5 kg wood, 0.7 â 1.3 kg charcoal, or 1.8 â 3.6 kg rice husks.â
https://energypedia.info/wiki/Biomass_Gasification_(Small-scale)
If you use the middle of the range value of 1kg/kwhr electric and have 1.33lb/gallon (.16kg/liter) char, at 15kw output you would use about 94 liters (25 gallons) per hour.
With my 55 gallon drum gasifiers, the useful volume is about 33 gallons, which would make your refill interval 1 hour and 20 minutes.
6 Likes
Maybe thatâs why mine ran just a little bit more âEfficientlyâ, not that a comparison of a 196cc to a 2L and a Single vs Flute nozzle even begins to make sense, like you said too many variables. My charcoal was sized smaller generally and had a density of 1.8lb per gallon. Mixed species mostly softwoods. Itâs not that it ran any better itâs just that I min-maxed weight per gallon in the barrel. When I ran the wood chipper for crushing charcoal it had an awesome consistency, almost like flakes. I need to replicate that in a larger setup that isnât prone to suffocation like my cheap electric chipper succumbed to. Right now my current mill gets the same density per gallon as you. If I classified my stuff in the same range as previous, 1/8" to 1/2" I may get my numbers up.
5 Likes
Thatâs good info Cody.
1.8lbs/gallon with a smaller size char is consistent with the trend.
My charcoal when powdered (1/8 inch and down) has a density of 4 lbs per gallon. If you could find a way to gasify powdered charcoal, it would be ideal for processing, transport and handling, and run times.
I have some ideas but I havenât tried any of them.
Anybody know of a charcoal dust gasifier?
4 Likes
Chuck, here is one I made a few years ago from a gas water heater burner using char and dust that came through a window screen.
11 Likes
Very nice Don!
Any idea what a gallon of 1/4 minus charcoal weighs?
5 Likes
Sorry, no. I never weighed some.
3 Likes
What nozzle did you use? Your classic jumbo grate style or a Simple Fire type?
3 Likes
I used a ceramic tig cup fed pressurized air from a computer fan.
8 Likes
Do you have more details on here somewhere Don? That looks ideal for the guys wanting to use wood gas for cooking fuel.
3 Likes