Converting chippings into fire bricks?

[hesslemount]

Does anyone know of a process that can convert your usual chippings into fire bricks? The reason I ask is I remember about 20 years ago the cub scouts used to sell fire bricks made from old newspaper which they mached and made into bricks. With so many chipping generated by so many of us it'd be ideal if we could pioneer a nationwide project with an institution such as scouts whereby they could use our chippings to make fire bricks. I know the fuel pellet product is well known and established now so why not make "the fire brick"? I'm tipping that the hardest part of the process (and probably the idea's downfall) will be in drying the chippings.

 

Just throwing ideas out into the mix here to see if anything comes of it. Anything which promotes our by products as a useable resource has to be beneficial to all involved.

[skyhuck]

You need hundreds of tonnes of force!! It generates a great deal of heat so drying the chip would not be an issue, but the equipment is VERY expensive to buy and maintain.

[Mick Stockbridge]

It generates a great deal of heat so drying the chip would not be an issue, but the equipment is VERY expensive to buy and maintain.

 

We had a pile of chip catch alight at the farm about a month ago. I assumed it was kids but the fire brigade reckoned it was internal combustion.

[skyhuck]

We had a pile of chip catch alight at the farm about a month ago. I assumed it was kids but the fire brigade reckoned it was internal combustion.

 

Not kids, imo.

 

Chip gets very, very hot! it ferments and will spontaneously com-bust.

[garth mc garth]

we had an indoor grass silage clamp catch fire once, fire brigade was using thermal imaging equipment to guide me to what parts of the clamp to dig out with the telehandler so they could cool it off. same goes with dung and woodchip, they all heat up as they decompose

[Mick Stockbridge]

Not kids, imo.

 

Chip gets very, very hot! it ferments and will spontaneously com-bust.

 

Ah spontaneous! Thats the word i should have used, not internal.

[skyhuck]

Ah spontaneous! Thats the word i should have used, not internal.

 

Would be both mate, as it would start in the middle of the pile.

[County4x4]

The briquetting process is a little more tolerant of moisture levels than pelletising for instance, but you need to be a fair way down from the levels in green chip. Too much moisture causes problems because when the briquettes are compressed by whatever means, the moisture turns to steam and expands - blowing the briquettes up in the process!

 

I would also think that chip may be a bit coarse on its own - you'd need some finer materials in there as well to get it to bind properly. It's the lignins and resins etc in the wood itself that are softened by the heat generated by compression - around 80 tons per square inch if memory serves - and these basically glue the briquette together.

 

I looked at an Indian built machine a year or two back which worked on a piston compressor rather than a hydraulic press or screw extruder - the installed cost would have been in the region of £45k. Fantastic piece of kit though - looked like "Old English" engineering - all huge lumps of cast iron and massive bearings with two half ton flywheels - not like these modern Euro jobs all encased in sheetmetal cabinets with buttons and lights and computer links to the manufacturers etc! It was pretty basic but very durable by all accounts - not like the screw extruders where the plants have welders working full time repairing the screws - they sometimes only work for an hour before they're knackered and need re-facing! They will also work with chopped straw, bark, nut shells, rice husk etc etc.

 

Cheers,

 

Andy

[surreyarborist]

What about binding the chips together with wax ie like a candle

[T14EES T14UNK]

What about binding the chips together with wax ie like a candle

 

A bit like DuraFlame logs. I think they were a byproduct of a pencil factory in the US weren't they. Chips might just need a bit more wax. How about some conifer resin to bind it?