Single Phase Pellet Mills, what are the Problems when making Wood Pellets?

Hi, I’m Chris. I started PelHeat.com back in 2007.

When it comes to making wood pellets, your choice of pellet mill is limited by your available source of power. For domestic properties and some commercial buildings, a single phase connection is used which has a voltage between 110v – 240v. For many commercial buildings, a three-phase connection is available which can carry a higher voltage of between 230v – 400v. When it comes to using a single phase pellet mill various limitations have to be acknowledged. These include the maximum power the pellet mill can consume.

The Power restrictions of Single Phase

Single Phase Pellet Mill
A single phase mini pellet mill

If you only have access to a single phase electrical supply you are limited by the maximum power draw the pellet mill can demand. On a standard domestic two/three pin plug the maximum motor draw without tripping will be around 2.2kW. If there is a dedicated connection (similar to that used for a cooker), potentially the motor size could be increased to around 7kW.

However, if you are intending to make wood pellets this is not a lot of power to play with. Quality wood pellet production requires high compression, which in turn demands a high power input from the pellet mill. Without sufficient power, a single phase pellet mill can run into problems.

Potentially Increased Pellet Mill Die Blockages

Blocked pellet mill die
A blocked die on a single phase pellet mill can easily happen.

The number of Amps (power) a pellet mill draws depends on the type of material being processed. For instance, a single phase pellet mill can quite happily process an oily animal feed mix into low-density pellets. However, when it comes to processing wood pellets there are more intensive power demands. As wood has a higher material density and the pellets are also produced to a higher density this can lead to complications. As the single-phase pellet mill starts to process wood pellets the amps will increase. If there is a change with the raw material feed rate or the moisture content changes this could lead to issues.

As the pellet mill starts to work harder to push the wood through the die the motor amps rise. With a single phase pellet mill, it’s very easy to reach the limit of around 6 amps. After this point, the electrical connection will trip out. If this happens with the material left in the die it will start to cool down and harden. Depending on the condition of the die this could lead to a pellet mill die blockage.

Productivity per Hour Restrictions

As a roughly general rule when it comes to making wood pellets it requires 1kW of pellet mill power to produce 10kg/h of productivity. Therefore, on a single phase connection and motor power of 2.2kW, the productivity per hour will be 22kg/h. This is where you really have to weigh up the value of your time to the volume of wood pellets produced.

Wood Pellets
It takes 1kW of power to produce 10kg/h of wood pellets

A pellet mill is not a ‘set and forget’ operation. You need to be actively engaged, monitoring the raw material and pellet press at the same time. Therefore, what you really need to consider is if 22kgs of wood pellets are worth an hour of your time. There is also the matter of pellet mill maintenance to factor in. Furthermore, it’s not really an hour of your time, it’s even more. You also have to factor in the time taken to prepare the raw material ready for the pellet mill. That means reducing it to a suitable particle size and moisture content.

You can only run One Piece of Equipment at a Time

Single Phase Hammer Mill
Single phase hammer mill

As previously stated, a single phase connection means all available power is used by the pellet mill. Therefore, there is no surplus power available to run a hammer mill for particle size reduction. If there was suitably available power you could be using the hammer mill while the pellet mill does its job. As with single phase, there isn’t sufficient power, you have to use one piece of equipment at a time. This therefore obviously increases the total time it takes to produce a fairly small quantity of wood pellets.

There are small hammer mills on the market that use small diesel engines. This would obviously mean you could be using both the pellet mill and hammer mill at the same time. It should be noted that small Chinese diesel engines are not very efficient. Therefore the cost to process the material could be much higher than you would expect.

Is there a use for a Single Phase Pellet Mill?

From reading the above it should be clear that a single phase pellet mill is not a viable pellet production setup for volume. The cost per ton when you factor in the labour/time is not viable. However, there is still a viable use for single phase pellet mills.

Research and testing before investment in a pellet plant is probably the number one use for single phase pellet mills. Before a significant investment is made in a pellet plant a pilot project can be set up to produce small volumes of pellets. This can be a ‘proof of concept’ to help to secure funding. It can also be a useful setup to train future pellet plant operators.

The other exception of use for a single phase pellet mill is for producing BBQ wood pellets. As the profit margins are so high for BBQ wood pellets it can be viable to produce them on a single phase pellet mill.

Final thoughts on Single Phase Pellet Mills

Many people start off looking into purchasing a pellet mill to make wood pellets from home. However, before such a decision is made it’s very important to learn as much about the process as possible. Making good quality wood pellets is a challenge, and even more so using a low powered single phase pellet mill. To make the process easier to deal with its recommend to consider a low inclusion pellet binder. This will aid the process and partly address the issue of power limitations with a single phase pellet mill.

Before you purchase a single phase pellet mill it is a good idea to have a chat with a local electrician who will advise on the best way proceed. A dedicated connection for the pellet mill will probably be their recommendation.

I hope you found the above useful. Remember, before you make any purchase make sure you have researched the process of making pellets thoroughly. With this website, I’m trying to produce as many helpful hints and tips from my experience over the years.

Is a Used Pellet Mill worth the Risk?

Hi, I’m Chris. I started PelHeat.com back in 2007.

When it comes to making wood pellets, looking for a used pellet mill may be an option to reduce your initial investment. However, there are potential risks you need to consider before such a purchase. Also before you consider purchasing any equipment I would encourage you to read my posts on how to make wood pellets. You will learn about the best raw materials to make wood pellets from and the perfect moisture content.

Why is the Used Pellet Mill available for Sale?

Used Pellet Mill
Used pellet mill from China

The fact is many of the used pellet presses for sale on eBay are where the individual has purchased a Chinese pellet mill and experienced issues. Now those issues could be down to user error due to a lack of information/experience on the process of producing pellets or the issue could be with the press itself. Either way, it will lead to the item going up on eBay with comments such as ‘barely used’.

If the issue was operator error you could potentially pick up a very cheap pellet maker that with the right help could produce wood pellets. However, it could have also been operator error that actually led to an issue with the press. The rollers may have been clamped down again the die, large pieces of raw material used in the machine etc. They may have found frequent pellet mill die blockages to be too frustrating. The risk is that in some cases there may be damaged bearings, rollers or die. In other cases the pellet mill casting could be broken, there is an element of risk to any used pellet mill purchase.

Are you actually Saving any Money with a Used Pellet Mill?

Flat Die Pellet Mill
Most used pellet mills available are flat die machines made in China.

Let’s presume you are considering purchasing a used/second-hand flat die pellet mill. Odds are that the machine was produced in China. However, there are a lot of resellers on the Internet making the process of making wood pellets appear much easier than it really is in order to sell their pellet mills. So an individual purchases the pellet mill only to realise the process is a lot more complicated than they thought. They try to get a refund which is refused so they try and shift the pellet mill on eBay.

They know they won’t be able to sell the pellet mill for what they purchased it for so try and get between 50% and 75% of the original purchase price. However, the fact is many of these resellers are marking up the price of the Chinese pellet mills by 200-300%. Therefore a second hand (potentially damaged) pellet mill on eBay may still be significantly overpriced.

Purchasing Directly from China

The reality is to is often a better deal to purchase a new pellet mill directly from China than to purchase a used pellet mill from eBay. You can use an import agent however they are going to charge you quite a significant service charger for purchasing a single press. So there are two options.

Asking to Purchase a ‘Sample’ Machine

Common Chinese Pellet Mill
A typical example of Chinese pellet mill

So the best place to get in contact with Chinese pellet mill manufacturers is Alibaba which is an online Business to Business market place. Simply search for pellet mill and various companies will appear. You can contact the companies and explain to them you are potentially interested in starting a business selling their products. You request to purchase a single unit as a test sample. Some will refuse but some will agree to the deal. You can then use the Escrow service offered by Alibaba. They then hold the money on the purchaser’s behalf and only release the payment to the seller if you are happy with the purchase.

Purchasing a Pellet Mill through AliExpress

So AliExpress is basically the retail side of Alibaba, instead of being business to business its sales to consumers. You may not be able to secure quite such a good deal as purchasing a ‘test sample’. However, you will be able to get a much better deal than purchasing a pellet mill from a reseller adding a 200-300% markup. You can also pick up spare parts of the pellet mills at a fairly reasonable price as well.