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Post by pyrolyse on Jan 5, 2017 8:09:00 GMT -8
Has anybody tried using wood briquettes in a Batch Box rocket? The reason I´m asking is that wood briquettes are really cheap in my neck of the woods and also widely available in supermarkets and so on. But... briquettes are meant to be used in either regular woodstoves or wood boilers, and by design they burn more slowly than regular wood. But they also have some qualities which are better than regular wood. They have a much more ideal moisture content, usually lower than 10%, and therefore are easier to ignite and burn more cleanly. But again, they are mostly designed for a slow burn in woodstove, which is sort countering the fast burn of the batch box. So basically, has anybody tried this?
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Post by peterberg on Jan 5, 2017 11:10:17 GMT -8
Yes, been there, done that, Pini-Kay briquettes to be precise. It works, not really slow but hot and fast although a takes bit longer than real dense tree species. Not much difference, since these things aren't as irregular as real firewood you need to stack a bit sloppy so there's some air gaps between them.
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Post by drooster on Jan 5, 2017 12:10:43 GMT -8
Peter : with a controlled heat source producing similar gassing to dry wood you may be able to tweak performance even closer to ideal, and tweak firebox+fuel arrangement and air channels too. I'm doubtful on Pyrolyse's "really cheap" claim but it could be interesting.
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Post by pyrolyse on Jan 5, 2017 12:32:09 GMT -8
Well Drooster, the local bargain hardware store (something called Jem&Fix) has bags of 10kg briquettes for 10 danish kroner (1.40 dollars) a couple of times throughout the heating season. That´ s pretty cheap.
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Post by pyrolyse on Jan 5, 2017 12:38:00 GMT -8
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Post by peterberg on Jan 5, 2017 12:44:37 GMT -8
These briquettes looks like RUF type. Never used those, but if you want to know what the difference is I could order some I guess.
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Post by pyrolyse on Jan 5, 2017 12:49:20 GMT -8
Yeah, exactly, they are the RUF type briquettes. Wow, that would be really nice of you to do that! Are briquettes a popular biofuel in Holland?
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Post by drooster on Jan 5, 2017 13:25:45 GMT -8
Ten kroner for ten kilos sounds good. (I don't use dollars)
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jrl
Junior Member
Posts: 101
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Post by jrl on Jan 5, 2017 19:44:31 GMT -8
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Post by pyrolyse on Jan 7, 2017 7:29:55 GMT -8
They look very similar to the RUF-type briquettes. Do you know which type of wood they are made from? The RUF-types are made from pine tree or some other type of light coniferous wood, and they burn pretty quickly and disintegrate (swell up and ignite) during the burn phase. The fact that they disintegrate during the burning phase is rather annoying in a regular wood stove, because they then burn too quickly and they also leave a very fine fly ash, which goes literally everywhere when you open to refill - but that´s rather ideal in the Batch Box, is it not? We want a large burning surface and an intense fire, right?
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jrl
Junior Member
Posts: 101
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Post by jrl on Jan 12, 2017 8:48:26 GMT -8
They look very similar to the RUF-type briquettes. Do you know which type of wood they are made from? The RUF-types are made from pine tree or some other type of light coniferous wood, and they burn pretty quickly and disintegrate (swell up and ignite) during the burn phase. The fact that they disintegrate during the burning phase is rather annoying in a regular wood stove, because they then burn too quickly and they also leave a very fine fly ash, which goes literally everywhere when you open to refill - but that´s rather ideal in the Batch Box, is it not? We want a large burning surface and an intense fire, right? I agree. They are ideal for the batch box in the sense that you get all that surface area igniting at once. That is after they swell and fall apart. The second load is always an absolute roaring fire laying new bricks down on top of the disintegrated ones that I spread around with a poker. I'm certain they are softwood like pine, but CT Biobricks brand doesn't advertise that. There are several other brands sold in my local area that all advertise being made from softwoods.
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Post by Vortex on Jan 12, 2017 10:10:03 GMT -8
Be careful not to put them so they are wedged tight in a firebox. I've seen them push the sides off of a stove when they 'swell up' - give them some room to expand.
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Post by peterberg on Jan 24, 2017 8:52:07 GMT -8
On the 10th of januari I ran a test with RUF briquettes, 6 of those. The development of the burn was very slow, so I started the test again when the burn was coming on. The briquettes were stacked in, a handful of splinters on top and lit with a barbecue lighter. I'm inclined to think one would need more kindling to set the pile alight. The diagram is just one, the test not optimized for this fuel, just following my own ingrained habits. The results are quite good, a smooth curve and high efficiency, nothing wrong with it. The CO decreased down below 500 ppm at 18 minutes and stayed there for 46 minutes. So, are RUF briquettes useable in a batch box rocket? I would say: yes, definitely.
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Post by woodrascal on Jan 26, 2017 7:12:49 GMT -8
It's worth considering that over here in the UK anyway, that 'RUF' briquettes can be of a huge range in quality and feedstock materials - RUF is the name of the briquette making MACHINE...
I've seen briquettes for sale (with the 'RUF' stamping) that have been made from various things including sawdust, planings, woodchip and rather alarmingly, MDF!
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Post by pyrolyse on Jan 26, 2017 16:55:39 GMT -8
I know it's the name of the pressing machine, but I have only seen briquettes made from sawdust. But I will agree that (especially the RUF-types) can be of varying quality.
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