Screw Press for Biomass Briquetting

I would try to tackle this with a fairly large diameter hydraulic piston pushing on a 2.3" diameter rod. From there, it is simple arithmetic.

On the long term you will get screwed yourself.

Wear and tear vs. a hydraulic cylinder. We used to shorten wood by 50% to compress the fibers and hydraulics turned out the best.

There really isn't a formula for the screw press, maybe intellectual properties. And the "close interlocking bonds" you talk about I beleive your referring to "lignum".

This is the 'glue' that hold it together. I understand its a form of a polymer. Which you would have come across in your research.

And the amount of lignum varies with plant species.

What kind of research? Library research or process research?

Or production output?

I had also done quite a bit of research in this for my line of work.

And what you are talking about is basically an extruder. China does make quite a bit of these. I'll see what kind of information I have, it may point you in the right direction.

Yes Phoenix911, you are correct it is called "lignum".

No wonder I can not find any formula for the design of said screw extruder.

It is library research which suggested for at least 25,000 psi to achieve 'gluing'.

Any help is greatly appreciated Phoenix911, I am having a hard time talking to fabricators here in my area. I am afraid they do not have the technical know-how to help.

I am afraid they do not have the technical know-how to help.

Been there and I know what you're saying

I'll pull what I have.

Not knowing your requirements I'll put this on the table, there are a lot of used briquetting equipment (in good shape) on the market now. (U.S.) Including extruders

Also keep this in mind, the diameter of your logs, depending on the moisture content any bigger you may have to make them hollow.

So you're fixed on a screw press for extruding... there are other ways.

But.... on the smaller production scale. China dominates the market with their equipment in price.

Also keep in mind, that the press is only part of the process, you may require a shredder/grinder and also drying equipment as well.

btw, welcome to CR4

I have some going info, private message me your email, and I'll send it.

Also some of it you can down load direct. Google "Designing the Sugar Cane Charcoal Extruder" you'll get a number of hits from MIT and others.

The one that I have is;

Designing the Sugar Cane Charcoal Extruder
By, Dexter W. Ang

Submitted to the Department of Mechanical Engineering
In Partial Fulfillment of the Requirements for the Degree of
Bachelor of Science in Mechanical Engineering

Maybe something like this is a thing to consider. Although it's quite lowtech and small output it does work.

with a briquette having a surface area of 0.005m^squared (0.05m x 0.1m) you'd have to press with 172.368.932 Pa (25.000 PSI) x 0.005msq = 861.844,66 Newton.

I'd use a lever or a hydraulic press if I were you (as also pointed out by others.)

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https://www.youtube.com/watch?v=G_LW38THm2s

https://www.youtube.com/watch?v=zomrikxAkiE

https://www.youtube.com/watch?v=oG9DKYCklLw

https://www.youtube.com/watch?v=PibuFjMZjNo

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As I said maybe to low tech but you could scale it with hydraulic automated presses and a conveyor belt.

Hope it's useful,

Dennis

I'd use a lever or a hydraulic press if I were you (as also pointed out by others.)

Not necessarily, It depends on the process, we rented a continuous mixer and extruder (Company's name was Brabender, based out of Germany, the distributor was based out of Canada)

One machine that does both mixing and extruding because we were reincorporating the tar back into the charcoal, so that the charcoal would have a binder for pelletizing.

Because we had stripped everything out of the charcoal for farther process to get the product we wanted.

But a press also doesn't take away from its validity at least for R&D.

Prior to running the above process with the mixer/extruder combo (as a pelletizer), I had used a 50 ton press in our maintenance shop to press samples just to find out the best ratio to use.

Cross sectional area is just over 4 in² so you need to generate a little over 100,000 lb force.

Assuming that you can easily apply 50 lb force to the end of you handle ("on the last crunch") you need a mechanical advantage of 2000.

If the handle is about 1ft long that's a circumference of about 75" So if the threads are about 75/2000 = 0.0375 (about a mm) apart you should be OK.

I've completely ignored friction in screw thread, but I reckon you will be able to exceed that 50 lb easily, especially if you add some weight, and, "spin" it down.

Not everything has a <...formula...>.

Hey guys,

Thank you for all the help.

I am now looking for a hydraulic press to test the biomass I will be briquetting. If all tests go well I will be looking into hydraulic press.

Fingers Crossed

additional info:

get your biomass under 10% and better yet under 7% moisture. raise the temp to 300 Fahrenheit. this "melts" the lignum. allowing better adhesion

Hello,

I tried pressing the biomass and achieved compaction. However when I tried carbonizing the briquette it unravels. Would you know of a solution to prevent this?

You either have a lower lignum in your biomass or the temperature isn't high enough for the lignum to bind.