Creating Friction by Crushing Wood Fiber

Just a thought on this subject. In the plasticizing process of plastic injection molding, plastic pellets are introduced into the barrel of the molding machine at one end of a square threaded screw. The screw rotates creating shear energy and frictional energy. For different materials different flight shapes are used to optimize this energy and plasticizing of the polymer. The barrel is heated normally using 3-4 separate zones of band heaters. During the injection process the square thread rotates forcing the pellets forward through the banks of heater bands. The screw rotation action generates heat which is supplemented with the heater bands and heat can be controlled by reducing the heat input to the heater bands for certain shear sensitive materials like thermoplastic elastomers. It is evident that some materials generate more friction and shear heating during this rotation of the screw than others. I wonder what type of wood you are using and in what for etc.

Now to your process. If you feed pulverized wood and feed it into a similar contraption you may drive off the wetness of the wood. So instead of adding saturated steam, you may generate enough shear energy to excite the moisture in the wood to turn to steam which may act to lube the passage of wood from the inlet to the outlet.

This may be an overly simplistic concept. In practice you may have problems with wood resin gumming up the screw etc. It would be relatively easy to experiment with an old molding machine.

I know that in this area of California I have witnessed massive old molding machines being cut up for scrap in the last year or two, as there is no market for old machines in the area. Check local mold shops, see if they would experiment with an obsolete machine or if they know of such machines at their competitors or friends shops.

Is pulverizing the wood chips between two rollers (similar to the 'mangle' your mom used to dry the clothes with), a viable idea. It is relatively easy to heat the rollers to aid in the drying process but the brute force approach of squeezing/wringing the chips will certainly eliminate moisture without heat. Scraping off the processed chips will be done with a doctor blade on the exit side of the mangle.You could also feed in a liner paper, plastic or even a metal liner material through the rolls to aid in soaking up the moisture and resin and giving you a useable sheet of wood.

I am kind-of shooting from the hip with wild ideas as there is not a lot to go on as far as your planned end result. More detail will draw out the bright minds who peruse this sight to help people.

Good luck.

2Tinker, I like the molding screw and will look into it. I have several designs on the opposing rolls that may work but still hope to develop a design using twin conical screws, long pitch to short pitch, to facilitate bulk feeding and compression with few moving parts and a uniform feed rate.

We are simply 'drying' uniform fir wood chips, the consistency of the finished product and exact feed rate doesn't matter...it's feeding a boiler firebox.

It's good to see another Tinker is still alive!

Oregon I see you have started a new thread , I just posted under the old "drying wood chips "thread to let you know I found a drum dryer on e bay located in California that I believe would be your best bet to achieve drying of large quantities of chips. Again it is Item #190296411464 in construction equipment under (other) subheading .I think that's the way to go I bet it could be had for a fraction of the asking price.

Best of luck Traditional

Traditional, we may be moving a drum debarker (for logs) from Louisiana to Oregon in a few weeks that is built like the one in Ebay. It is 15'-3" diameter, 80'long and weighs 280,000 lbs.

I sure hope we don't need something as large as the peanut dryer for the wood chips!

I think your up to something that far exceeds "a small independent community"

why the need for misdirection I doubt if anyone cares if your starting a facility other than the competition but seeing as we are on the opposite ends of the country that would be your business.

Traditional, I didn't mean to ruffle your feathers! The big drum debarker is being purchased by one of my sawmill customers. My part was to design a plan for how to break it down into legal loads for the railroad and reassembly at their facility. They don't know about and won't be involved in the chip drying project.

Did you see in a prior post where we are now going to process only 2 tons per hour?

Not ruffled except I have had chip buyers come up with story's about end use rather than being up front I hope your project comes together as planned

Traditional, I hope I find a feasible plan before I miss out on the opportunity! I'm almost out of time and am still not confident enough to submit a proposal that I could stand behind. I have benefitted greatly from the knowledge, experience and brainpower of this group. If I miss this opportunity I may still venture into this field.

Thanks!

If the requirement is to reduce moisture and as a product deliver pressurized water ( steam after pressure reduction) then your intentions to provide mechanical energy to boil the water is highly inefficient.

If you still want controlled fiber separation , how do you see your process being better than the Defibrator disc approach? You can recover heat in clean steam after fiber separation through a dirty to clean steam exchanger

I recall that in mechanically pressing water from wood products you quickly reach a limit whjere the internal cell water will not come out. Pressing alone will not get you to 30%

Biomass, thanks for your input, I want to reduce moisture only...don't care about steam or water or boiling or contrlled fiber size. Is the Defibrator disc the same as I mentioned in the hardboard plant?

What if we tear or shred the chip before pressing? How many psi and how much time to eject moisture down to 30%? What would you do?

Check out this equipment. We ran trials on woodwaste and it was as effective as anything seen We did not go ahead as we had a sludge component which limited results

http://www.saalasti.fi/bark-master-eng.html

Biomass, very impressive and expensive looking. How many psi will they put out? I like the swing open design for regulating pressure, following bulk material pile size and especially the ability to pass a rock without stopping the process.