# Mechanical briquette press

## Main Question or Discussion Point

Dear Sirs,

we have bought a mechanical piston operated briquett press and we have a question regarding mechanical briquette presses, if anyone has any knowledge about them. We produce briquettes mainly from dryed oak wood, 8-10% kiln dryed.

The problem: we have a mechanical briquette press from a company Spaenex (Germany)... the output is 300-400kg/h and the power is 15kw. The problem is that the briquets are pressed but they get soft and break very easy.

Our theory is that the problem is something with the conic (tapared) die? The conic (tapered) die is maybe not the right shape, how should the die be like? The die must be smaller at the start and then bigger to the end? We habe so far made 2 dies but we didnt get the best results yet...

With best regards,

Nejc

Related Mechanical Engineering News on Phys.org

As per i think you have to add some additives at mixing stage.

This will strengthen the briquette and make it hard.

Danger
Gold Member
Welcome to PF, Posterslo.
I might be misunderstanding your question, but it seems to me that you have your die in backwards. The output should be the final shape that you want, which would mean that it goes from larger to smaller rather than the other way around.

Well if you have the drawings of the Dies Then I can give them the look and What is Pressure exerted by your machine.

ups, i wrote it wrong :), we have it right in the maschine, i ment going from bigger diameter like 52mm to 48mm thats to the middle of the die and then in the middle from 48 mm to 50mm, the final briquette diameter is 50mm.

Now we dont know if we should make it 52->48mm to the middle of the die or trought the whole die... or should we make it 52->48 to the middle and then 48->50 to the end. And also the angle is the problem.

No, no, the maschine must go without additives, because these kind of high pressure presses are making briquttes without it.

the pressure is about 2000 kg/cm2

i dont have a drawing but here are two pictures of the die

#### Attachments

• 80.3 KB Views: 349
• 72.8 KB Views: 359
Well if it up ---- > down process then it will have the top area to be lesser than lower area .

As when the die returns it can easily get away without breaking the corners.

The Variation of the top and bottom can be handle with close proximations

the sawdust is pushed with a pistion trought that die, the shape of the die is really important for the briquette quallity, also the friction must be there so the material gets hot to around 170 degres, so that the lignin in the wood can act like an adhesiv.

i dont have a drawing but here are two pictures of the die
I have attached the basic design. to get the briquttes without break.

#### Attachments

• 4.6 KB Views: 315

adhesive purpose can be solved by it :)

Danger
Gold Member
we dont know if we should make it 52->48mm to the middle of the die or trought the whole die... or should we make it 52->48 to the middle and then 48->50 to the end.
I'm not an engineer (or any other kind of scientist), but my gut instinct is that you should go from 52-50. If that doesn't provide enough compression, increase your input stage to 54 or so. Wait for a real engineer to respond, though; I don't want you wasting your money on my advice if it's wrong.

thanks for your help, yes the problem is we cant finds anybody who knows exactly how the die must be, we know that it must be slightly tapered from start, but how much, for how long...etc...we tryed to contact companys who produce these maschines with no response yet....

hat is the shape of your punch and how far into the die does it go?

Zivjo Nejc,
Mi se ukvarjamo z prodajo opreme za peletiranje in briketiranje...mogoce ti lahko pomagam na kaksen nacin,ce si pa ze resil tezavo bi se vseeno rad slisal steboj ker smo tudi mi kupli eno briketirko od istega proizvajalca pa bi rad poklepetal o tem steboj.
Hvala ti vnaprej!
Lep pozdrav ,
Primoz K. - 070 259 025
Eko Navitas doo