PelHeat Mobile Pelletizer

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

Webmaster said:

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.

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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

Eric Johnson said:

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?

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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

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.

http://pelheatblog.com/2009/01/12/pelheat-update/

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

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.

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:

http://pelheatblog.com/2009/01/12/pelheat-update/

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

Chris

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.

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