Mobile Retorts

[TGB]

...

Will try again later, TVI.

Most appreciated if you could. The info so far has been really good and most helpful.

 

For longer posts, I find it handy, to construct the post in a word processor of some ilk and save the file on a regular basis/every few mins. That way, if it goes honey-shaped, the core of the text done so far is saved and I'll only have lost a small section. When it comes to posting, it's a matter of copy+pasting into the reply box.

 

Note. Don't cut+paste. Because if it goes all honey-shaped before it is sent or even while it is sending. The product of your hard work could still be lost without a trace. So best to copy it; and if the send goes well, you can then delete the original construction. Or else if you think it'll come in useful for future replies, save it.

 

An extra plus, is the construction of text and or accompanying photos, can be carried out off-line. So if you get distracted, your work will be safe and the page won't time-out if your hungry pet/child decides to sponaiously dig up your prized camellia.

Edited April 11, 2014 by TGB

[the village idiot]

Good idea with the long posts. I thought for the time being I would send a series of shorter posts so I can send them off before the mysterious mistress of fate banishes them to the digital nether regions of doom.

 

Regarding lifespan of the kiln- this is a very pertinent question, and the honest answer is that I have no idea... yet. Robin and Geoff the designers and marketers of the exeter retort have done over 70 burns in their original prototype and it is still going, although due to the heat stresses involved in charcoal production it is now a rather different shape from when it started out.

On the face of it this sounds seriously alarming, but with charcoal kilns there is invariably metal warping and the exeter retort is designed so that it can be literally beaten back into shape. For this purpose it is handy to know a good local metal worker, or live within easy reach of exeter. Since I bought my kiln the inner chamber which holds the wood to be converted has been redesigned and strengthened, so should go a lot longer before needing attention.

Another weak point is the baffle plate which slides in between the charge chamber and the fire underneath. Robin and Geoff are experimenting with a stainless steel baffle but results are not yet out.

If the whole kiln wee to be made out of stainless it would probably outlast the sun but it would probably be at least double the price, and it wood be a brave woodsman who decided to take the plunge.

There are a handful of retort owners dotted about, some with the improved inner chamber and some who have got more burns under their lengths of baler twine than me. I will get a list of email addresses together as it would be well worth speaking to as many owners as you can, including the formidable Alan Waters who is almost certainly made of charcoal . I'll also post some thoughts on biochar, which the exeter retort was originally designed for. This is an exciting developing area well worth keeping an eye on.

 

Until we meet again, TVI

[TGB]

More interesting info. Than you again!

[the village idiot]

There was and maybe still is grant funding available to help with the purchase cost. It depends somewhat on geographical location and unfortunately I didn't qualify, but I know that some of the other retort owners got 40% of the cost paid.

It would be worth asking Robin and Geoff about this as I believe there may even be a Exeter retort grant application template floating around somewhere that potential applicants can use.

Getting the grant would obviously significantly reduce the payback time on the kiln.

 

It is probably worth saying at this point that charcoal production does not make you rich. It is quite hard work for, by many people's expectations, little return. I would struggle to make a living from charcoal alone, but it does play an important part in my woodland-management activities. It provides an income stream from all the ugly wood and neglected coppice material, and importantly you can get on with other jobs whilst the kiln does it's thing. You do need to stay in the vicinity though to keep an eye on the temperature.

 

If anyone wants to see a used retort in the flesh you are more than welcome to come for a woody walk and see the retort. I am close to Ipswich in Suffolk. I may even be able to rustle up a sausage! -Stop giggling at the back-

[TGB]

Yep, charcoal won't make someone rich quick. But at present, a lot of branches that would be suitable for charcoal production but nothing else, are either getting stockpiled and slowly rotting or burnt. But finding the time to tend 50gal drums is increasingly difficult. Plus conversion via a retort, can utilise smaller material than would normally worthwhile.

[TRADITIONAL LOGGERS]

How bad are the internal buckles in steelwork? Does it produce consistent loads of charcoal from all species?

[the village idiot]

The internal buckles on my (un-strengthened) inner chamber are quite severe. It is sagging around the support pillars which carry the weight of the charge chamber. It still works fine, but it means I can fit less wood in. The machine is going to exeter in the autumn to be rectified.

 

In terms of converting different species, I have only tried hornbeam, ash, oak, field maple, birch and hazel so far. All of these have converted perfectly and I see no reason why other species wouldn't do the same. I know that some of the other owners are using beech and softwood successfully. Hazel makes the best charcoal in my opinion.

 

The retort isn't fussy about the diameter of the material. I load my kiln with anything up to about 6' diameter. You really don't want to be messing around with splitting wood for charcoal if you can avoid it, and I charcoal all hardwoods that are too small for firewood.

 

I have a customer who sells 'species specific' charcoal into the london restaurants. They are always looking for more retort charcoal to buy in. I also have other good outlets for bulk charcoal which I can pass on if anyone decides to go for it. You will achieve a better margin selling direct to the retailer, or even better- direct to the public, there is however significant further processing involved.

[rovers90]

Whilst I whole heartedly agree with the production of UK charcoal and how it uses up timber that would not be used for anything else, I fail to see how the maths stand up.

 

You paid £10,000 plus vat = £12,000 and yet only achieve £130 per burn. The machine is not going to pay for itself until you have done 93 burns but you state the manufacturers have not done this number yet and the machine is already suffering from the use you have given it. And that does not take in to account your other costs either. From your excellent posts it sounds as if the machine would not reach this number of burns without constant modification and rectifying.

 

I'm in no way criticising, as I say I just fail to see how the numbers stack up and if the retort could eventually achieve that number of burns without more time and cost being expanded.

[the village idiot]

Hi Rovers90.

 

Your points are certainly valid. Investing in the exeter retort was a gamble and the payback period is undoubtedly long. The machine will need a certain amount of maintenance over time but this will not amount to huge sums and as long as the retort is looked after and not abused there is no reason why it couldn't go on making top notch charcoal for many years.

 

I appreciate that the exeter retort will not be compatible with everyone's business model, especially with our fixation on maximum profits and quick returns. Also, as mentioned in a previous post, other retort buyers have benefitted from a 40% grant for the purchase. This obviously shows the figures in a very different light. I did not manage to take advantage of the grant, but I am an idiot after all!

 

It is also worth pointing out that it is possible to achieve much more than £130 per burn if you set yourself up to supply direct to local shops or the end user. One of my customers is selling 6kg bags of mixed hardwood retort charcoal to the public for £17 plus delivery, and he cannot keep up with demand.

 

I believe somebody asked in a previous post about insulation. Both the doors and the body of the retort are insulated with a ceramic blanket type material. This does an excellent job, and even when placed directly on the ground the grass underneath remains un-scorched.

[hedgesparrow]

chap has one of the exeters and he got 100% grant for his believe half was from the county council. as it was promoting aciant crafts.

so may be orth asking council if they will fund a bit