Pellet mill attachment

[ihookem]

Maybe you could mix drain oil or old veggy oil with the dust so it acts like moisture, then just burn it with the oil still in it.

 

[dangerdoc]

How long is 'quickly' do you think? every ton of product? every 10 tons? Certainly a cost factor to be added in. I noticed both places have the dies advertised so I assumed you would likely need a spare set on hand.

I think you can plan on every 200-300 hours. The tonnage will depend on tons per hour the machine can produce.

I priced an inexpensive machine, more expensive machines may have more durable dies so your miliage may vary.

 

[RonMar]

Well from what I can see, the electric motor unit is direct drive so about 1800RPM input to the mill gearbox. The diesel run model is powered by a changfa diesel engine(pretty durable unit by most accounts). People take these and direct drive 4 pole 1800 RPM generator heads to make power plants. The belt drive from this engine to the mill gearbox in the E-bay pics shows nearly a 1:1 ratio, so again approx 1800 RPM into the mill on the diesel version. Since it is belt drive, that leads me to believe it has a fairly robust input bearing, so direct drive from a PTO shaft would probably be no problem. But I havn't seen a pully side view to confirm if it has an outer support bearing along with the input pully. The PTO version on the Pellet Pro site appears to be direct drive with no gears or pullies, at least as best I can tell from the small pic. It either has some different internal gears(unlikley IMO) or with 540 RPM input, it just runs at 1/3 the output capacity of the diesel version.

You will need a hammermill or some other form of material reduction to get the input material to less than 3MM-1/8" cube size.

Those lower prices on the E-bay auctions are FOB china. the price for the bare grinder for making your own PTO powered unit is under $1000. But, that means you are the importer, and will pay all customs, dock, unloading, inspection, storage and longshoremans coffee and donut fees associated with it's delivery to tacoma WA. Plus any shipping from tacoma to your final destination, which is why pellet pro charges what they do.

 

[Luremaker]

Best source for pellets is switch grass/hay field i was planning on using somthing like soy beans for a binding agent. I also have a maple house and all the sawdust from there I was hoping to include. look to waste first then to raw. making pellets from wood wouldent be a effective solution even the current stock is all sawdust like byproducts from lumber mills.

I am getting a pellet stove that can burn pretty much any thing that is dry and goes through the auger.

Shelburne Farms Tests Grass Pellet Heat

What kind of pellet stove are you getting? I have researched a little and most pellet stove manufacturers it seems do not recommend grass pellets. Do you know if Sheburne Farms has actually used any grass pellets other than a few test days?

GrassBioenergy.org: Frequently Asked Questions

 

[RonMar]

I E-mailed that vendor on E-bay and asked some questions. He said the nominal input RPM for the pellet mill is 2200 RPM. He said the diesel version is upgeared slightly to get from the nominal 2000 RPM of the engine to that 2200 RPM input. So I am guessing that the PTO version at Pellet Pro has a planetary gearbox on the input as it has the same pound per hour rateing with only a 540RPM input. It is a small pic, but if it is a planetary gearbox in that pic of the PTO model, it sure is a small one.

He asked if I was interested in a 3PH model, and I told him yes, and also in a similarly powered hammermil for processing the raw material. I also asked him for a total price delivered from the wharehouse in Tacoma into the back of my truck. He replied that he has sent a message to his supplier in China so We are waiting on what they have to say.

I could see a neat little 3PH assembly with both onboard. You drop sticks or chips from your chipper, or hay/grass into one chute, and get pellets out the other You will then of course have to cool and dry the pellets afterward...

Whatever pellet material you burn will have different combustion characteristics. A stove that can do multiple types will need a controller, pellet feed and possibly some airflow control that can provide differing volumes of combustion air and fuel to allow for this. That is probably why a manufacturer of a particular stove says use only 1 particular type of fuel. They probably havn't done the research to determine if a different type of pellet will burn correctly/safely in their design of stove.

 

[charlz]

So I am guessing that the PTO version at Pellet Pro has a planetary gearbox on the input as it has the same pound per hour rateing with only a 540RPM input. It is a small pic, but if it is a planetary gearbox in that pic of the PTO model, it sure is a small one.

It would appear all the gears are in the lower portion of the unit. Perhaps they just have to change out those gears to make it take a 540rpm input? I don't know if there is enough space in there? Wouldn't this effectively reduce the horsepower getting to the press portion though? Not sure if I could run one with my 16hp b7100 or not.

I could see a neat little 3PH assembly with both onboard. You drop sticks or chips from your chipper, or hay/grass into one chute, and get pellets out the other

It would seem that drying the source material, if required, would be the biggest and most expensive part of the challenge.

You will then of course have to cool and dry the pellets afterward...

there is a video on youtube that looks like it is one of these mills, those pellets look very hot coming out. In the video on the PelletPros site those pellets do not look nearly as hot. I wonder if that is a factor of input material moisture?


Next trick is storing the pellets. By my calculations you would need about 4.5 (55gallon) drums per ton. Drums would be easy to move around with the tractor. I guess you could also use those fabric feed bags that handle 1000 or 2000lbs if your tractor could handle it.


I wonder how well the pellets hold up mechanically? Obviously the less you handle them the better but you wouldn't want them to turn back into sawdust in the stove.

 

[schmism]

I guess you could also use those fabric feed bags that handle 1000 or 2000lbs if your tractor could handle it.

put them on a pallet and lift the pallet with the 3pt

 

[RonMar]

It would appear all the gears are in the lower portion of the unit. Perhaps they just have to change out those gears to make it take a 540rpm input? I don't know if there is enough space in there? Wouldn't this effectively reduce the horsepower getting to the press portion though? Not sure if I could run one with my 16hp b7100 or not.

Perhaps they change the base gearing, but adding an additional 4:1 ratio. the vendor I asked the questions of got back to me and said they do not, at least his supplier does not make any base gear modifications. Pellet pro's may be having something custom built for a PTO application. The base price for the smaller press without motor is under $1K and since you are building the 3PH carryall for it, it would probably be best to put together a 4:1 pully arrangement to get the mill input up to 2200 RPM from 540.

As for HP needed, they run these easilly with a 15HP diesel. What is HP? HP is torque, or work performed over time. Lets say you have 1FT/LB of torque on a shaft turning 100RPM, and that equals a given HP. Double the torque at the same RPM(twice as much work being done), you double the HP. Double the RPM at the same torque(also twice as much work being done in a given time period) and you also double the HP. A gearbox is a torque multiplier/divider. lets say you have that same 1FT/LB-100RPM and you run it into a 2:1 gearbox. Your output will be 2FT/LB of torque, but at 50 RPM. Those two changes cancel each other out, so the net HP change is 0. There are of course friction losses in the gearbox, so you will loose a little HP in the form of gearbox heat.

It would seem that drying the source material, if required, would be the biggest and most expensive part of the challenge.

there is a video on youtube that looks like it is one of these mills, those pellets look very hot coming out. In the video on the PelletPros site those pellets do not look nearly as hot. I wonder if that is a factor of input material moisture?

Yes, probably a factor of moisture and also of mill speed. You squeeze anything it gets hot though from compression and from friction passing thru the dies. I think they need a certain ammount of moisture to form a good pellet though, so even if the source material is dry, I think they may need a final dry after pelletized.

Next trick is storing the pellets. By my calculations you would need about 4.5 (55gallon) drums per ton. Drums would be easy to move around with the tractor. I guess you could also use those fabric feed bags that handle 1000 or 2000lbs if your tractor could handle it.

I wonder how well the pellets hold up mechanically? Obviously the less you handle them the better but you wouldn't want them to turn back into sawdust in the stove.

Well the pellets I buy are made and dried, then bagged and thrown 50 to a pallet then wrapped and put in a wharehouse by forklift. then again by forklift to a truck and moved probably a thousand miles bouncing down the highway where they are unloaded by forklift. then again by forklift to my truck, then unloaded by hand to my storage area. This is a minimum af what they are moved and seem to hold up well. Homemade pellets would probably endure far less movement.

That vendor also quoted me a price of around $1K for a bare hammermill, but I am guessing it would also need a step up drive system to get from 540 to around 2000 RPM.

 

[charlz]

Yes, probably a factor of moisture and also of mill speed. You squeeze anything it gets hot though from compression and from friction passing thru the dies. I think they need a certain amount of moisture to form a good pellet though, so even if the source material is dry, I think they may need a final dry after pelletized.

Reading through the Testing Log and FAQ on the PelletPro's site it seems experimentation is the order of the day. They put through sawdust/planer shavings apparently without grinding or issue but then got some sawdust that needed water added to form pellets. Drying the pellets after the fact is certainly easier than drying the sawdust before. Looks like a certain amount of drying and cooling is required anyway.

Well the pellets I buy are made and dried, then bagged and thrown 50 to a pallet then wrapped and put in a warehouse by forklift. then again by forklift to a truck and moved probably a thousand miles bouncing down the highway where they are unloaded by forklift. then again by forklift to my truck, then unloaded by hand to my storage area. This is a minimum of what they are moved and seem to hold up well. Homemade pellets would probably endure far less movement.

The pellets in the pics on PelletPro's don't look like they are as 'shiny' which makes me wonder, but you are right, a lot less handling is needed. Dust might be more of an issue though.

That vendor also quoted me a price of around $1K for a bare hammermill, but I am guessing it would also need a step up drive system to get from 540 to around 2000 RPM.

I'd have a hard time buying a hammermill that way when I know there are lots around in my area that are not being used. There is one on my Craigslist for $150 right now and it is likely American made with parts still available.


So did you get a FOB to the back of your truck price for the pellet mill?

 

[shvl73]

So did you get a FOB to the back of your truck price for the pellet mill?

I'm curious as well.

 

[BXRICK]

A friend of mine designed, built, and owns two very large wood pellet plants on the east coast. He sells them as "New England Wood Pellets".
New England Wood Pellet - Home Page

Anyway, here's the non-secrets I know:
- A hammermill is a requirement, as is equipment to remove non-wood to help protect the press.
- The sawdust has to be REALLY dry before you start. It takes a lot of heat. A kiln-dried 2x4 is not good enough.
- Moisture (this is a trade secret, and I'm actually not sure what he uses right now and exacty how it's done) is then added back in right before pressing.
- Anyone can press a pellet with any wood. What matters is how much burnable wood you get into the pellet.

Basically, you take essentially all the moisture out, and then add a very little
back - just enough to get a bind. Any more, and you hurt the efficiency of the pellet (it contains more water and therefore fewer BTUs than necessary).

It's definitely a case where economy of scale works out.

 

[RonMar]

I'm curious as well.

That was what I asked for when I asked for prices from him, so I am assuming that is what I got, but I will confirm that.

 

[RonMar]

Well that was not the delivered price. If both the hammermill and the pellett mill without motor/shafting were ordered together, it would be roughly another $200 shipping and $600 in broker fees to get them onto the back of my truck...

 

[Bill Barrett]

I was just at a energy fair in Custer Wi., Got to see a pellet mill up close looked like the one in this thread. If any of you are machining savy, dies and rollers would be a piece of cake.
Edit; just looked at the link again, 259.00 for replacment dies isn't bad. Still would be fun to make them.

 

[charlz]

I was just at a energy fair in Custer Wi., Got to see a pellet mill up close looked like the one in this thread. If any of you are machining savy, dies and rollers would be a piece of cake.
Edit; just looked at the link again, 259.00 for replacment dies isn't bad. Still would be fun to make them.

Did you get to see it in action?

 

[Bill Barrett]

Did you get to see it in action?

No darn-it, the guy selling them wasn't even there. He had a pad to fill in name and address for more info.

 

[PoppaRex]

looks like this thread has somewhat died, so i'd like to revive it.

I've been thinking about this over the past year or two. Just bought a small tractor MF GC2310 (23 hp) and so i am now rethinking this with a little more seriousness.

So just some thoughts on the subject...

Has anyone made any progress?

Do the prices requested seem a bit high?

Can I build one?

Seems like the press and die are the key componant. Other than that you need the pto shaft and gear box. Is there any existing implement that delivers the gear ratio required to power a pellet mill? Can i cannibalize something to get what i need?

I saw some vague questions regarding moisture content. What i have found is that most sites reference a pre-pelleting content of 12 - 18% with a finished moisture <8%. SOme commercial places use the waste dust to generate heat for the dryers.

Also there was a comment about not pelleting durring the winter as it's too wet. I'd think the opposite. The air is much dryer in winter than spring. The difficulty is bringing the temperature up to drying temp, no?

I am looking at using miscanthus x Giganteus (Elephant grass) as my source. Trials in europe get up to 18 metric tones per acre. More if there was a method to keeing the leaves on. The leaves fall off leaving a bamboo-like cane up to 12 feet tall. I finally located a source and purchanges 4 plants. I'll see what the growth rate is truely like. Additionally, i am considering leaf waste from fall collections. Infrastrutire is already in place with town leaf collection sites. I am gussing that using such material as the source would eliminate the need for a hammermill and i might get away with a series of weed whackers in a tube design.

Have fun!
Poppa

 

[SFish]

Where I used to live (WV) it is wet in the summer and dry in the winter. Where I live now (CA) it is wet in the winter and dry in the summer. Steve

 

[PoppaRex]

Steve, we could make pellets there in the summer and here in the winter!

NOTE: After additional searching, i also find references to pre-pelleting moisture content needing to be in the 8 - 12% range. Must have to do with the particular type of material being used.

 

[Darren]

There's a commercial pellet plant in this county. One of the issues other than density is the quality of the saw dust. The plant buys hardwood saw dust by the tractor trailer load. They won't buy any saw dust that has pieces of bark. The saw dust must come from a mill that debarks the logs first.