PelHeat Mobile Pelletizer

[PelHeat Ltd]

Hi Everyone

My name is Christopher Scott, I'm the director of PelHeat Limited in the UK. We are currently developing the PelHeat Mobile Pelletizer, I have recently created the website at www.pelheat.com, that contains some information on the project. The reason Ive posted this topic is really to hear your opinions on the principle of the product. We are a small company, and we currently only have plans to sell the unit in the UK, and purhaps Europe. However if there is enough interest from US, bringing the unit to the US might be a possibility.

Thanks

Chris

 

[webbie]

Interesting product.....

One question would be what the feedstock must be in terms of wood.....

It seems most wood is high in moisture content, and therefore drying the wood is a large part of the problem. Could you explain how this would be done in a mobile unit?

I can imagine a scenario where people would start to use pellet boilers and furnaces if they could have local production from something like this - for instance, land clearing companies could find houses that were very close by and deliver bulk pellets there. The same might go for industrial or commercial applications.

 

[Eric Johnson]

The pellet plants I've visited are paranoid about bark in addition to moisture. Does your machine make industrial grade pellets, or are you claiming that it can produce commercial-grade stove pellets from otherwise unprocessed wood residue?

 

[PelHeat Ltd]

Interesting product.....

One question would be what the feedstock must be in terms of wood.....

It seems most wood is high in moisture content, and therefore drying the wood is a large part of the problem. Could you explain how this would be done in a mobile unit?

I can imagine a scenario where people would start to use pellet boilers and furnaces if they could have local production from something like this - for instance, land clearing companies could find houses that were very close by and deliver bulk pellets there. The same might go for industrial or commercial applications.

Your correct controlling moisture within the raw material is the key issue; however in producing an affordable small-scale unit, moisture control equipment is not possible, as it is not in any other small-scale pellet equipment available.

We are currently experimenting with the simplest and cheapest methods for controlling moisture within the raw material, which will be included on our website. We have used a dehumidifier to control moisture within the raw material, which worked but was uncontrollable, i.e. it could easily dry the material too much.

We have been looking at dehumidifiers where you can set their relative humidity (how much moisture air can hold) at a certain level, and switch off when that level is reached. For example a if you set the dehumidifier to a relative humidity of 80%, the unit would reduce moisture in the air to that level and switch off, here is a link:

http://www.woodweb.com/knowledge_base/Ratios_Relative_humidity_to_moisture_content.html.

At 80% relative humidity the moisture content of the material will be 16%, perfect for making pellets, and an automatic process. If the moisture is a few percent too high, the pellet mill can be used to reduce moisture, because of the high temperatures in the mill.

Our unit can also make pellets from all kinds of biomass including Miscanthus, Reed Canary Grass, and Straw. We have even made pellets from wastes such as cardboard. The advantages of many of the crops is that their moisture content at harvest in many cases is correct for making pellets

Our product because of the fact it cannot control moisture its self, cannot make pellets by inputting material that has too much or too little moisture, this is the compromise in offering an affordable small-scale mobile unit. We are committed to educate users to different methods in material preparation. As we found our self’s, as the users skills increase with processing materials, it becomes much easier to understand what will and will not pelletize, and what to do. I have created a guide on our website at http://www.pelheat.com/Downloads.html , so interested parties can understand the process, and decide if producing pellets is for them.

Thanks for the interest

Chris

 

[PelHeat Ltd]

The pellet plants I've visited are paranoid about bark in addition to moisture. Does your machine make industrial grade pellets, or are you claiming that it can produce commercial-grade stove pellets from otherwise unprocessed wood residue?

Hi Eric

This is a very good question, to put it simply it completely depends what you are burning the pellets in (What make of pellet boiler/stove), and what level of maintenance you will accept (More bark in wood pellets, means more ash, thus more maintenance).

Pellet producers have to produce premium quality wood pellets, i.e. low bark because those pellets will be accepted by any pellet boiler or stove, and have the lowest maintenance levels possible for burning pellets, which is what consumers expect.

In terms of our unit, your pellets are only as good as your raw material. So if you input wood with bark, your pellet will have more ash than an industry premium pellet.

Pellet stoves generally need pellets with low ash, or the stove will not operate properly. We have a more general approach in that we want to make use of more biomass that’s available, that means wood with various levels of ash, Miscanthus pellets, Straw pellets, even cardboard pellets. To do this we require a boiler that can handle fuels with various levels of ash content, however we have to carry out more maintenance than someone burning premium wood pellets. We have chosen this approach for cost reasons, as we can obtain what ever is the cheapest raw material, but also for environment reasons because there is only a limited amount of premium wood available, and for the pellet market to grow and be a realistic heating option more that just premium wood must be used. But it’s not for everyone.

There is more on this subject on our website at:
http://www.pelheat.com/Pellets.html

Thanks for the interest

Chris

 

[PelHeat Ltd]

Hello Everyone

Just a quick post to inform you of an update on our progress with the mobile Pelletizer. We hope to have a product available by around July all things going well. Here is a link to our Blog on the update post.

(broken link removed)

We are now working with an established British engineering company based in Sheffield, the engineering capital of the UK. They have many years experience exporting their products all over the world, and we will now be able to bring the product to the US when development is complete.

Thanks for the interest

Chris

 

[renewablejohn]

Would that be July 2009 or is this a different machine to the one which was supposed to be ready in July 2008. Not being cynical but I would have thought you needed to test the equipment on the UK market prior to Marketing in the US.

 

[PelHeat Ltd]

Hi John

The first prototype proved the principle for process, however after further evaluation we decided continued development and testing was required before we made the product available for purchase.

Before the units are made available to the market we are producing two final test production machines, one is going to a US organisation and one to a UK organisation.

If there are no issues with the final design, the product will be available for purchase by anyone, in the UK or elsewhere. We hope to reach this stage by July this year. At some point in the future I will be informing our mailing list that the units will be produced to order on a first come first serve basis.

 

[drdoct]

Christopher, I've got a few questions. Your hammermill looks a little small. What size screen are you using? Is it a stirrup mill or just plain old hammers? I guess it all depends on what the final product will be. I grind wheat bran through a 6/64 with no problem, but I'm using a full circle hammermill. Have you experimented on a universal mill like a Kemutec? http://www.kemutec.com/htm/products/kek/mills/universal.htm . I would think the best type of mill would be an acm from Hosokawa. (broken link removed to http://www.hosokawa.co.uk/acm.php) . I've seen corncob furfural go in an acm at 40+% moisture and exit around 9%. They heated their air intake using a furnace to get it dry. You'll lose some of that moisture just by grinding alone too. Not sure how well that cyclone works sideways though. Kice makes a horizontal separator that works good for when you don't have the space to run a big cyclone vertically. (broken link removed to http://www.kice.com/products/cyclones/HZS.1000.pdf) . How much moisture loss are you seeing when you pelletize? I would think you could firm up the pellet and drop another 10-15% off the pellet mill. All that depends on how long it's sitting in the die being forced out. I use this type of equipment every day in our flour mill. I just don't know how your going to keep it all on that little trailer to make it work. Something else you definitely need is a feeder on your hammermill. The Mikro mills have auger feeders on them look at the 4 TH mill. What is your capacity on this mill? Just by looking at it I would say +- 500lbs an hour or so. I guess it all depends on what you are pelletizing though. I've got a few old cpm pellet mills here... I should start playing with them to see what I could come up with. If there is anything you think I could help you with them pm me and I'll try to see if I can get you an answer.

ps... it's somewhat hard to see the exact setup because the pictures are from so far away.

 

[PelHeat Ltd]

The pictures are of the first prototype unit; the design now is very different.

The hammer mill uses plain old hammers, and we use a range of screens depending on what needs to be processed, and what pellet diameter is produced.

The productivity of the hammer mill far exceeds the productivity of the pellet mill.

A cyclone separator can work up to 45 degree, however at the cost of efficiency. The new design means the cyclone will be in the vertical position and then lower for transportation.

The first machines will have no drying facilities and will require a material with moisture content around 15%. We are looking at drying solutions, and I have had talks with Hosokawa on developing a system similar to the one you describe.

We are now using a slightly larger twin axel trailer.

There is more detail on the new designs at:

(broken link removed)

If you keep an eye on the Blog, any updates will be posted there.

Chris

 

[drdoct]

I'm thinking instead of using a bin/silo for storage between the hammermill and pelletmill you should use a vertical mixer. That would allow you to make a mix if you need to add binders to the mixture before pelletization. Also, I don't know how much you've worked with silo systems, but bridging is a serious problem especially with things just milled. A mixer would eliminate this bridging problem. This whole platform is going to be mega expensive though. Especially in stainless. Hammermill--$50K+, Cyclone & airlock $3K+, Pelletmill $50K+, Diesel motor & hydraulic systems $40K+... it seems to go on and on. I don't know many people willing to invest $250,000 into something that fits on a single trailer and pumps out 1000 pounds of pellets an hour that would equal about $100 an hour for pellets. Add in the diesel fuel and costs associated with bagging/transfer to silos and feeding the machine... I just don't see the return at all. Don't get me wrong... I really love figuring these things out, but it just seems a little much. Now... if you used carbon steel and could find equipment used that you could refurbish... then I could see it working. Or for someone like me that has a whole shop of this type of equipment... maybe. Mine wouldn't be mobile though, it'd be 3phase here at the plant. I'm not trying to burst your bubble or anything... just wondering where the return comes in? Am I that far off on prices? I know I cannot afford new stainless equipment so I'm just wondering how farmer joe would be able to swing this.

 

[PelHeat Ltd]

Bridging is definitely an issue, which we have experienced; therefore we re-designed our hopper to have a double auger system, with a horizontal auger then length of the hopper feeding the vertical auger to the pellet mill. Both augers will be powered via the hydraulics and be variable speed to tailor to the chosen raw material.

There are various reasons for the unit being mobile which are explained on the Blog. Also not all locations have 3-phase power. So diesel power and hydraulics are the only option for a mobile solution. The Perkins diesel unit can also operate on bio-diesel.

The productivity of this unit will range between 100-200kg/h for high-density materials for example hard and softwood pellets, and 200-300kg/h for low-density materials like straws and grasses.

We estimate the units at current exchange rates to cost be less than $40,000.

 

[drdoct]

So using the maximum 300 kg/h which is 661 lbs it will take a little over 3 hours to make a ton of pellets. A lot of people don't understand how hard it is to make pellets. We used to make animal feed pellets and our pelletmills were always going down. It's hard to keep bearings in the rollers because of all the heat and pressure and dust. I like the idea of using recycled vegetable oil as a binder though. It may create a bigger fire hazard. I remember lots of burned pellets and I would think that when those hit the air and have oil right at the flash point then it may create a little problem. Maybe not though. On your bin system... one of the biggest secrets to getting material to flow freely is to have at least one side of the silo straight. This makes the hopper look like an offset, but it works. Live bottoms do work great too as long as they are the same width as the bin. You will need a feeder on the hammermill also because mills do not like inconsistent feedings. This could be as easy as a screw conveyor (auger) that swings out and sits on the ground with a little hopper on it, geared to the speed of your hammermill capacity. On the wood, do you start off with sawdust or wood chips? Does the hammermill work very good on grasses and straws? We grind our wheat screenings with a hammermill, but it doesn't produce anything like a powder or anything uniform. I really hope you can get it all tuned up and be able to sell these for around $40,000. I sure had your equipment costs way higher. WAY. Have you made many pellets off your prototype? Do you just cool them on a tarp or something? We used a cooling tower when we made feed pellets. I'd love to see a video when you get it all running. I find it all interesting and challenging.

 

[PelHeat Ltd]

Yes, one side of the hopper will be vertical, and the horizontal auger will be the full length of the hopper. Keeping pellet mill and hammer mill bearings properly attended is very important, and high quality temperature resistant grease must also be used.

We have successfully processed a wide range of materials through the hammer mill, including wood chips, straw and grasses. The input material must have a diameter smaller than 1 inch, and for grasses and straws it’s generally easier to load the hammer mill if the material has been pre-processed, via a forage harvester for example. We don’t currently use a screen below 3mm, some particles do pass through which are larger, however the percentage is insignificant.

We have made many different types of pellets with the equipment. For example on www.woodpelletmill.com, all the pellet images are of pellets we have produced on our equipment. Pellet cooling can simply be carried out in a well-ventilated area. In the future we hope to develop a pellet cooling and bagging solution to accompany the original equipment. We also intend to do the same for a raw material dryer and mixer.

Thank you for your interest and support. Designing a unit such as this is very challenging due to space, size and weight restrictions. However we feel our new designs produce a good small-scale unit for raw material size reduction and pellet compression.

Chris