Wood gas, take 3

This is getting bigger and better. I'm convinced that this time I have a stove that can actually be used in the rural communities of South Africa.

For this experiment, I was given a big NAN tin (Thanks Mike) and I scavenged a Ricoffy tin from my kitchen. The results from this one, were beyond my wildest dreams... but I'm getting ahead of myself here. Let's tell the story in pictures.

As before, here's the stove. Packing in at 436 grams, it's quite a bit bigger than the previous one.

The wood for this experiment, came in at 694 grams.

And I decided to use some kindling to get things going faster. Weighing 50 grams.

That made a total of 744 grams of fuel. Not all the wood would fit into the stove, so I held 340 grams in reserve.

Everything ready, and the fire was lit at 20:36

A note here on starting the fire.
In my previous experiments, I started the fire from the bottom, and added wood. In this experiment, after being reminded of the concept of an upside down fire (Thanks Darren), I decided to try burning it from the top down. The result was faster gasification, and almost no smoke. The only caveat is, that you have to use enough kindling at the top, to make sure you have coals that will burn the wood below.

The kettle with 3 liters of tap water went on the flames at 20:40. As you can see, gasification was already happening.

Now things started cooking, and I was getting beyond excited. Something I should not have allowed, as I might have gotten better results if I remained calm. Thing is... I didn't expect this:

At 20:56 The water was boiling. That's right folks, 3 liters of water, boiled in 16 minutes on a total of 404 grams of wood.

At this point, I have not touched my reserve pile yet.

And the stove was still going like a house on fire... and at this point I should probably stop using puns, right?

In my fit of excitement, I thought I'd push the edge of the envelope, and try to boil another 3 liters of water.
So I dumped the hot water in the kettle and filled it again, with 3 liters of tap water.

The kettle was back on the stove at 20:58

A few minutes later, gasification failed.

With careful blowing on the stove, and adding wood from my reserve pile, I managed to get gasification going again.

A note on restarting gasification.
Just adding wood isn't a great idea, you get lots of smoke again. If you add wood and then add kindling on the top of that, you'd probably get better results and wouldn't have to blow the fire back into flame, like I had too.

All wasn't lost though, as I had the second lot of water boiling at 21:25.

If I remained calm here, I would have added all the reserve wood to the stove, before putting the kettle on again, and added some kindling to the top again. Unfortunately I wasn't thinking clearly and the water only boiled 27 minutes after going on. I still boiled 6 liters of water on a total of 744 grams of fuel. Not bad at all.

This time though, being out of fuel, I decided to keep the pot on and see how long the water would keep boiling. I didn't realize I was in for a long wait

At 21:46 the water was still boiling vigorously.

This picture shows the amount of steam coming out from under the lid.

It started rattling so much I had to lift the lid to bring down the noise levels.

At 21:50 I decided enough is enough, and did the sensible thing.

At 22:03, things started cooling down.

At 22:09, the water stopped boiling, and I took the pot off.

At 22:30, the stove was cool enough to handle.

So I collected my tobaco tin again. Remember the 23 grams it weighs.

Collected all the remains from the stove again.

And got quite a surprise, again. A total weight of 39 grams.

Leaving the weight of the remains at 16 grams.

And here's the summary:

The first 3 liters of water, boiled in 16 minutes, using 404 grams of fuel.
The second 3 liters of water, boiled in 27 minutes, using the remaining 340 grams of fuel.
The collected remains weighed 16 grams, adding an error factor of 4 grams makes the total 20 grams.

i.e. 2.68 grams of remains for every 100grams of fuel
i.e. 97.32% of fuel gone

The experiment was concluded at 22:40, with a total duration of 2 hours and 4 minutes. The fire kept going much longer than anticipated.

Personally, I find these results stunning. The nice thing is, that I have the build of this stove fully documented in pictures. The intention being to get it neatly set up, as short and simple as possible, and then to get the info out to rural communities.

Before I do that though, there is one more experiment that has to succeed:

I have to cook on this stove. I have to prepare a meal, not just any meal either. It would have to be a meal that would be cooked in the rural areas of South Africa.

That means pap, enough to feed at least one family, that being a rather relative term in this case.
I'll have to get a bigger pot to cook in and learn how to prepare pap. As luck would have it though, I'm married to a lady that knows her way around a kitchen, and she's no stranger to cooking fires either.

Expect to see all that happening soon.