Simple-Fire

Small Engines Charcoal Gasification
#181

So, will 1" pipe work still with a 55 gallon drum or should I go with a larger nozzle? (I will be running the 10 hp generator)

Also, should I still go up 4" from the bottom and then center the nozzle in the middle of the barrel or go a bit short of center?

From what I have read here, it seems that the placement of the nozzle depends on the velocity of the incoming air. Is it correct that with a 1" pipe I could have it centered, but if I were to use a smaller tig welding cup nozzle (1/2") I would have to move it closer to the incoming edge of the barrel due to the higher velocity?

Am I right in that the goal with the nozzle placement is to have the “candle flame” of the combustion zone in the center of the reactor container?

Thanks everyone for the help!

#182

Hi Tim, A 1" pipe is plenty large enough for your 10 hp generator. No problems there. Nozzle placement 4" from the bottom is a good location. This will give room for the ash to accumulate. Nozzle placement should be no less than 8" from the edge of the drum. You do not need to center it. The “candle flame” does not have to be in the center of the reactor container. Just get it far enough from the edge of the drum so the charcoal can form an insulating buffer. You are using a very big drum for a small engine and nozzle placement is not as critical in charcoal gasification as it is in wood gasification. Be aware that once you get your 55 gallon drum filled with charcoal and running your 10 hp engine it will probably run for at least 4 hours if not more. That drum holds a lot of charcoal!
Gary in PA

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#183

As I am thinking about the nozzle, I am wondering if other materials would work or not. Would copper or bronze pipe work and not oxidize (not sure)?

Also, if I go with the larger 55 gallon drum size, would I need a cyclone or not? (Maybe just a coffee can filter with open cell foam)?

Can someone explain when a cyclone is needed or not needed? I hope to build a number of different sized simple-fire’s now.

#184

Hi Tim,

A cyclone is a good match for wood gasification. If too much dust collect in your 55 gallon drum in time you will need to clean that out and screen the charcoal from the dust.

Jeff

#185

Hi Tim, No you do not need a cyclone on your proposed arrangement. A 55 gallon drum full of charcoal being sucked by a 10 hp engine will not pull much dust out. Go ahead and just use the foam filter. How about making it from a 5 gallon pail instead of a coffee can though. More surface area to help clean your charcoal gas.
Nozzle??? Yes, a copper pipe will work, so will an iron pipe, stainless steel, ceramic and so forth. Just start experimenting. I’ve used most of them and keep comming back to stainless steel for ease of use and price. Just figure the nozzle is a consumable item that needs replaced from time to time.
Gary in PA

#186

Copper does have a lower melting temperature, roughly equivalent to glass. I would guess one would have to run a really fine line to make good gas but not melt your nozzle.

#187

Gary or any of you charcoal experts, I need a little advice.

Using what I had on hand mostly I built a little larger simplefire for my mower (Snapper zero turn with a 19hp Kawasaki two cylinder). I had a left over piece of 16" diameter water heater and rigged up a nozzle with a number 15 tig cup on a 3/4"pipe. A 1.5" stainless pipe slipped over for a shield. It goes up to a 1" pipe on the outside of the 2" pipe cap.

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I ran 2" hose from the gasifier to a mixer (no filter just for the test run) and had a 1" pipe and 1" gate valve for an air inlet. After warming it up with a shop vac and figuring out I had to remove the valve to get enough air I got it running pretty good. I couldn’t move it around but did engage the blades and it seemed to have plenty of power.

Now the bad parts.

My charcoal is what has came out of my truck and been stored for over two years. It must have absorbed a lot of moisture because there was water collecting in the hose to the mixer.

Also the temps after running for a few minutes were around 300F in places around the water heater and 130 at the lid.

I think it will need to be a lot taller to get any run time out of it but I’m not sure if exhaust tempering will be enough to keep the temps down on the outside of the housing since I had plenty of water already. It may be better just to use this for a smaller engine. Mainly wanted to see what everybody’s thoughts were before trying to mount this thing.

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#188

Look out Marvin before you get hooked! This incredibly simple way to run an engine is wickedly addictive. They do get hot though but charcoal is a very good insulator. Does your nozzle terminate about a third of the way in? Did you flare it at night? if so what color was the flare? Nice nozzle by the way.

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#189

What was the size of the charcoal? We usually aim for 1/8 to 3/4" size with a good cross section of sizes. It should certainly be dried if it is that wet.

#190

Thanks Mr. Don
Nozzle was about 5" in. The outside was about even temperature all the way around the shell, just a little to hot though. No night flare, just a clear flame with a lot of moisture coming through.

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#191

I ran the charcoal over a 1/4" screen and it was up to 3/4" big. It didn’t feel wet and had a lot of dust floating around when I screened it. It went straight from my truck to a 55 gallon drum that’s been under a carport. I was really surprised to see that much water coming out.

#192

130 and 300f sounds about right. The moisture is above the reaction zone so no help there.

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#193

Hi Marvin, Yes, the charcoal will collect atmospheric moisture over time which will condense out as you note. You just have to cool the gas down and let the water condense out. Charcoal size is very important as noted and maybe try a slightly smaller screen than the 1/4". In other words, have more smaller pieces of charcoal mixed in to slow the flow of hot gases.
Personally, I’d like you to go to a 1" air inlet instead of the 3/4" one. Also shorten it up to four inches, It just looks too long. A shop vac for start up is way overkill unless you throttle it down, just too much vacuum. I have no problems starting on the old low vacuum bilge blowers.
Gary in PA

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#194

Thank fellows,
I’ll try to get some fresh charcoal sized a little better and rig up some exhaust recirculation to it.

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#195

Nice removeable nozzle!

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#196

Marvin,
Don’t forget the most important, i second Gary here, … don’t use to much vacuum to startup…

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#197

Marvin,

It is normal to have the surrounding moister into your charcoal, that would not be the main problem, unless rain is dripping on it.

As general rule: quality fuel in = quality gas out… ( The sht in is sht out principle… )

I check my systems as follows: after a steady , warming up the gasifier run, where the first fumes are smoke from the moister, i shut down my flame and let the gas flow… if the gasifier is warm, i have no smoke and the gas will burn easy, the engines will run and start smooth.
The gas will be smokeless and odorless.

Once i overpull, to much airflow in the gasifier, the incoming air has no time (dwell time) to convert all it contents, the gas will be more moist , more hot and less powerfull (high Co2 content)
The gas , after warm up, will keep some fumes, moister in the filters and the flame becomes more reddish on the tips.
( imo: technically this comes from the already converted humidity into H2, that will combust into Co2 and water after leaving the reduction zone, also generating heat and some methane… )

To clarify: if the engine asks 100 volumes, the nozzle should deliver less then 100 volumes, (somewhere between 60 and 80) measured at the same speed …
The rest of the volume is from the carbon going from solid into gas state.
The less Co2 in your gas, the better your gasifier.
O2 to be avoided coz it will create some after the hot zone combustion to… ( air passing the reduction zone caused by overpull ?)

The lenght of your nozzle: i use as indicator ( huray for stainless) the lengt of blueish colorisation from the nozzlepipe.
Just keep the blue line a bit away from your wall and it will be fine.

Start without the exhaust gasses to find the best for you, then ad some as needed.
If your hot zone gets to cold, gas quality will be poor.
I tend to work on the nozzle tip temperature, melted quite some stainless and ashes been vitrified often… sizing up or down, just make it hot enough to do the desired job, quench with exhaust if to hot…
The best of the Simple fire… Its simple, it works… and it is addictive… Thank you Gary G :grin:

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#198

2 pictures of the nozzle from my tuktuk, you see the vitrified bamboo charcoal is covering the nozzle tip and how far it heats up the pipe…

Oh yeah, stainless 1" pipe

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#199

Koen, I am surprised to see the obstruction caused by the vitreous carbon.
This should create a significant restriction?

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#200

Yes Thierry, it obstructed the flow, so i was not able to run longer…

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