[Stoves] WEB ROLLER BRIQUETTING PRESS ?

[AJH]

On Mon, 31 Mar 2008 13:21:41 +0200, adam u partner wrote:

>seeing all the bags of pillow-shaped charcoal briquettes here
>around in Europe (mainly sold at petrol stations)
>and written often "import" on the bags-
>it means that many companies succeed in producing these
>briquettes with roller presses.

Certainly Chris, it's a mature technology, just like ring die extruded
pellets have become. I looked into just his sort of arrangement to see
it I could make a smaller pillow briquette from charcoal fines, so
that it would feed in one of our pellet stoves but the finances
suggested a minimum annual throughput of 500 tonnes/annum were
required to justify the capital cost.

Some of the binders used in the imported barbecue briquettes in UK
were not acceptable for the standards being set for pellet fuels, they
included coal tar and bitumen amongst other things.

My experiments were mostly with starch ( I boiled up potato peelings
and used the liquid from that to mix my charcoal dust. I felt at the
time getting the right aggregate sizes was important to minimise the
amount of binder needed (i.e. the various sizes of char particle
should fit together well without voids, small particles being in the
interstitial spaces of larger ones). If you look at how they achieve a
smooth lime mortar by grading the sand carefully you will appreciate
the idea.

Even then I didn't make a very dense briquette using a meat mincer as
an extruder. I rolled the briquettes, still damp, through a shallow
container with PVA adhesive diluted to the strength used for sealing
concrete floors and this imparted a tougher skin.

AJH