Pellet presses are one term used to describe a pellet mill or pellet machine. Pellet presses come in various different sizes ranging from a small sized press such as the Mini Pellet Mill up to large scale commercial pellet plants. There are several different designs of pellet press including the flat die and the ring die designs.
The Flat Die Pellet Press Design Disadvantages
The flat die pellet press was the first design and it is the simplest design of pellet press. The majority of small pellet presses are based on the flat die design and they are manufactured in China. The advantage of the design are that they are very simple to produce and also very cheap to produce. However in terms of pellet quality and control of the process the majority of flat die pellet press are lacking the necessary features. Also the relationship between the rollers and die causes a skipping action. This skipping action means increased wear on consumables such as the roller and die and bearings. Skipping also generates increased friction which raises energy consumption of the pellet mill. These factors together mean that the flat die pellet press uses more energy to produce pellets.
The Ring Die Pellet Press Design Advantages
The flat die pellet press was developed at the turn of the 20th century, then around the 1950’s the design was improved with the ring die. All pellet mills that PelHeat offer are based on ring die designs. The majority of pellet presses used in large scale commercial pellet manufacture use the ring die pellet press design. The main benefits being reduced electrical consumption and increased life of the main consumable parts such as the rollers and die. The Mini Pellet Mill is one of the very few small pellet presses to work on the ring die design. First material is entered into the hopper, the material needs to be in particles smaller than 6mm and have a moisture content below 15%. Material is fed through the hopper via an auger into a conditioner where water and vegetable oil can be added. The material is then metered into the pellet mill compression chamber. To learn more about the equipment we offer and our consultation service please click the links above.
The pellet mill designs we offer here at PelHeat have a long history, for instance the pellet press designs used for the pellet plants actually date back to 1950’s animal feed plants. As this equipment has a large farmer client base the principle of a PTO pellet mill has been requested by our clients more than once and we have looked into the idea.
While technically simple the effect on the process and pellet quality do not meet the standards we demand of our products. The image you can see to the right is a typical example of a PTO pellet press imported from China. Typically for a pellet mill of that size you will able to produce 50 kg/s of wood pellets, up to 100 kg/h of animal feed and require a 30-40 HP tractor. We do appreciate from the customers perspective the principle setup may appear ideal. They already have a tractor so a separate diesel or electric motor is not required, reducing the cost of investment.
However there are limitations, and the first is of material input control. Many clients are not aware of how important the rate of feed into the pellet mill is on pellet quality and press productivity. On all our presses we have variable speed feed systems from a hopper. However with a PTO pellet mill setup there is only one source of power at one speed, therefore a variable speed control system is not possible. The second aspect is torque, while diesel engines do have a lot of torque compared to a gas/petrol unit they still cannot compare to an electric motor, particularly at variable speeds. There is also the question of running costs as a PTO setup is the most inefficient way to produce pellets.
Finally there are the serious safety concerns. Many people die each year from PTO related accidents, and with a pellet mill you are standing directly next to the shaft and many people choose not the fix the recommend protective covers. We do not wish to be responsible for any serious injuries or even deaths associated with using a PTO pellet mill, therefore this unfortunately something we cannot offer. However if you do decide to purchase a PTO pellet mill from say china and you need support to get the pellet mill operating you maybe interested in our five free guides and consultation service.
At PelHeat we only offer pellet mills and pellet plants that use the ring die design. There are several reasons why, but to boil it down the ring die pellet mill design is far more superior to the flat die pellet machine design. This is not just our opinion, if you go to visit a large scale wood pellet manufacturing plant today you will find that over 90% of those facilities will be using ring die presses.
Benefits Of The Ring Die Design
One of the main reasons that this is a superior design to the flat die press is that it does not suffer from roller skip. Due to speed differences between the point of contact between the rollers and die, roller skip is a significant issue for flat die pellet machines. Ring die systems do not suffer from this issue as there is no difference in speed between the die and rollers at any position.
The benefits of eliminating roller skip are reduced power consumption, extended consumable parts life and improved pellet quality. There is only one feature that flat die pellet mill manufacturers claim that it is superior to ring die presses and that is material flow of low density materials such as straw and other grasses. While this can potentially be an issue for some ring die pellet mills, it is not the case for our equipment.
The 22kw and 30kw presses we use in our pellet plants are built on a vertical material flow design, the same as flat die machines. Therefore our systems also have the single benefit of flat die pellet makers and none of the other issues. Our pellet mills and pellet plants have been used to produce pellets for many different sectors and industries.
Previously we installed a miscanthus pellet plant for the production of fuel pellets. However one of the most common enquires are for small wood pellet plants. Not only do we offer testing services as well as the Mini Pellet Mill, we also conduct our own tests on the combustion results of various pellets. Our pellet boiler can cope with even high ash content fuels, this makes it an excellent pellet burner to see how some of these other fuel pellets burn, such as grass pellets. If you would like to learn more about the process please click on the consultation button on the right for five free guides.
Before I go into the challenges involved in producing a small single phase pellet mill I should just quickly explain to those who don’t already know what single phase means. 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.
The Single Phase Mini Pellet Mill
So to put it simply we have much less power available to play with on a single phase connection. However we took on even more of a challenge. High power consumption home appliances such as hobs and ovens have their own circuit breaker to the main fuse box, you cannot simply use a standard plug. To make our Mini Pellet Mill a truly portable device that could easily and quickly be setup in any location we did not want a fixed connection we wanted it to be through a standard plug socket. We achieved this as you can see in the video, but it is challenging.
Firstly we use the ring die pellet press design to reduce the wasted friction energy seen in flat die machines. We then specifically sized the die to suit a 2.2kw motor which is the largest motor that can be operated off a single phase connection. It is even possible to run the machine from a single phase US 110v supply. Something to note about electric motors is the start up torque which takes a lot of power, therefore keeping the peak within the limits of 110v is very difficult. Some of our competitors offer gas/petrol or diesel pellet makers. We only offer electric setups due to the limitations of internal combustion engine setups. The Mini Pellet Mill is the only machine we offer for single phase however, all our larger production equipment requires a three phase supply.
There is a question I often get asked in the emails I receive so I thought I would write a page to try and make things clearer. The question is “Can I use the Mini Pellet Mill to produce my own fuel pellets for my pellet stove?”. In one sense the answer is yes, the Mini Pellet Mill can produce fuel pellets equal to premium grade wood pellets if you have a suitable raw material. However the real question is not if it’s technically possible but if it is a practical use of time and can you recover your investment within a reasonable time frame? To these questions the answer is generally no for most people, however producing fuel pellets from home was not really what the Mini Pellet Mill was designed for.
When is there a need for a small pellet mill?
We offer the Mini Pellet Mill primarily so researches have a small pellet mill that operates on the same principles as large scale production machines so they can conduct tests. There are many small pellet presses on the market today, with the majority imports from China. However these machines follow the basic design of the flat die pellet mill which is today rarely used in commercial production plants.
The design and features of the Mini Pellet Mill are identical to most pellet presses in operation in pellet plants today. However while the Mini Pellet Mill is often used in laboratories it is also used in other circumstances. We do have customers who produce niche high value pellets such as custom bird, animal and fish feed and other high value pellets such as BBQ pellets.
While some of these customers may also produce fuel pellets for their own pellet stoves and boilers, its not the primary use for this small pellet maker. So in summary owning a small pellet mill is not an economic investment of money or time for the average person to produce their own fuel pellets without a secondary need for research or business.
At PelHeat we very occasionally have used pellet mills in stock. These would mainly be used Mini Pellet Mills that are surplus to requirements once a client decided to start the setup of their pellet plant, however many clients actually keep their Mini Pellet Mills as a testing/training machine. Any used pellet mill we do have in stock would be checked over first and serviced.
As part our consultation service we often get asked about other used pellet mills clients have seen on websites such as eBay. The prices of some of these machines are very low and the appeal is obvious, however the real condition of the machine and its potential to produce pellets it’s an unknown.
A Chinese Purchase Gone Wrong
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 is the former where its operator error you could potentially pick up a very cheap pellet maker that with the right help (with our guide and consultation service) could produce pellets. However it could have also been operator error that actually lead 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. Therefore the mill may have damaged bearings, rollers or die. In some cases the casting could be broken, you just don’t know.
So is a cheap used pellet mill worth the risk?
It’s a gamble for sure and one that only you as an individual can make. If there is no broken parts on the pellet mill we maybe able to give you the education you need on making pellets and using the equipment through our guides and consultation service to get it working and making pellets. If the die, rollers or bearings are broken depending on the type of press we maybe able to direct you in the right direction to get the replacement parts from China. However if the casting is broken really that’s game over and it’s only worth its scrap value.
Here at PelHeat we offer a very specific range of pellets mills and plants designed and made here in the UK. These machines use only high quality materials and ring die designs, therefore these presses are not suitable for all projects and budgets. We also offer a consultation service to help people looking for other equipment.
What is the productivity of pellet mills you have for sale?
Our equipment is focused on the small scale project. For instance for research such as lab testing and training before investment in a pellet plant we offer a Mini Pellet Mill. This very small ring die machine will produce between 20 kg/h and 100 kg/h depending on the raw material being processed. The pellets plants are also focused on the small scale, with a productivity ranging from 250 kg/h up to 2,000 kg/h for fuel pellets made from wood or other biomass materials. To learn more about this equipment and to watch several videos please visit our products page.
Why do you only have UK pellet mills for sale?
We have decided only to offer premium pellet production equipment because from our experience only quality machines can produce quality pellets. However the premium quality of the pellet mills we offer does mean they cannot fit in with everyone’s budget.
Please review the equipment we have to offer, if it cannot either meet the productivity per hour you require or fit in within your budget we do also offer a consultation service. With this service we will discuss your project with you to help provide guidance in purchasing and operating various types of pellet mills.
Here at PelHeat we focus on small scale pellet equipment from our Mini Pellet Mill to our pellet plants. The equipment we offer is designed and manufactured here in the UK. If the pellet plants below are not suitable for your project for any reason we also now offer an affordable consultation service.
The productivity per hour of these pellet plants ranges from 250 Kg/h of wood/biomass pellets (single pellet press) up to 2,000 kg/h of wood/biomass pellets (multiple press plant). For lower density materials such as feed pellets the productivity per hour of the plants is much higher, for instance a single press pellet plant can produce up to 1,000 kg/h of feed pellets.
The Pellet Plant Process
The video above gives an introduction to the features and components of a typical wood pellet plant. The process starts with a raw material bin feeding a gravity hammer mill. If the raw material is above 15% moisture a dryer would be installed before the hammer mill.
After the hammer mill a small amount of binder (modified corn starch) can be added to the raw material to aid the process. The material is then carried to the top of the pellet mill to the conditioner chamber, here small amounts of water/vegetable oil can be added to aid the process within the pellet press. After the pellets are formed a knife cuts the pellets to the desired length.
The pellets now pass over a screen known as a fines sieve to remove dust from the pellets before they are cooled and carried to a storage vessel. From here the pellets can be then packaged into small bags or large dumpy bags.
Automation and Labour Costs
Automation is very important when it comes to operating a pellet mill and pellet plant. One of the highest costs in all forms of manufacturer is labour. Therefore keeping labour costs under control and to a minimum is very important in keeping production costs down and profits up.
Many other small pellet production lines on the market today offer either no automation or very limited automation. For a pellet plant to be truly automated each process needs to be aware of the other. As you can see from the video below all of the components on this small pellet plant are linked together through one central control panel. This means that you have precise control over the process and if there is an issue at any stage of the process the control panel will alert you to the issue. No other small scale pellet plant offers you such a sophisticated pellet plant control system, replicating the process of professional plants.
Typical Small Pellet Plant Customers
Today pellets are been used in many different industries and markets. Wood pellets are just one example of the type of pellets that can be produced. Before the fuel pellet market even existed the animal feed market fulfilled most of the demand for small pellet plants and mills.
However now due to the rise in the cost of fossil fuels and the demand for low carbon renewable energy, wood pellets and other biomass fuel pellets are the fastest growing market for pellets. These pellet plants have been purchased by saw mills and other wood waste processors to make wood pellets to meet the demands of the industrial and domestic markets. Farmers are also installing these small scale pellet plants to process biomass materials such as Miscanthus, Straw, Hemp and other grasses into fuel pellets. There are many possibilities to produce pellets for different uses efficiently on a highly automated small scale pellet plant.
Installation and Commissioning Of The Pellet Plant
We can provide a complete turn-key installation of the pellet plant at your location. Once an order has been made and the plant has been delivered to your location, engineers can be sent to completely construct and wire up the electrics on the small pellet plant ready for use.
We will also provide a full commissioning of the pellet plant to check the plant is in full working order. Our team will spend a few days with the intended operator to teach them the process of operating the pellet plant and the necessary maintenance that needs to be carried out. The operator will be educated in the process of making quality pellets, and how to adjust the process to maximise pellet quality, minimise energy consumption and wear of consumables such as the roller and die. This service is vital for you to be able to efficiently operate the pellet plant safely and keep the small pellet plant running for hours on end.
What Materials Can Be Used In The Pellet Mill?
Many different materials can be compressed into pellet form for many different uses. Wood pellets are very popular and the pellet mill can process both hard woods and soft woods into pellet form. Wood pellets are generally used for fuel in pellet stoves or boilers, alternatively they are also used for animal bedding and for BBQ/smoking pellets.
However wood is just one material which can be compressed into pellet form. Many other biomass materials can also be compressed into pellets such as Miscanthus, Reed, Hemp, Switchgrass and other straws and grasses. You may have a more unique material which you wish to compress into pellet form. Our small scale pellet plants are highly flexible and can be quickly modified to change the parameters to pellet different materials.
The Mini Pellet Mill: For The Home, Lab or Small Workshop
If you are interested in producing pellets on a small scale, the Mini Pellet Mill is the most advanced small pellet mill on the market. Though small in size the Mini Pellet Mill has features seen only previously on professional large scale professional pellet mills.
Testing, Training and Research
Through replicating the compression process of commercial machines the Mini Pellet Mill can be used to conduct material tests and training before investment in a pellet plant. Many of our Mini Pellet Mill customers originally started discussing their need for a small scale pellet plant and decided to start their project with the Mini Pellet Mill.
Single Phase or Three Phase Supply
The pellet maker uses a 3kW electric motor which operates at full capacity on a three phase electrical supply. We can setup the machine to operate from a single phase supply where the motor runs at 2.2kW through a standard electrical socket. The press can be setup to operate from most international voltages and Hz, including US domestic 110V supplies.
Raw Material Hopper
Material is fed into the top of the machine, at the base of the hopper is a variable speed feed auger which moves the material into the conditioner below. Before the raw material is placed into the hopper it must be reduced to a suitable particle size. We now also offer a Mini Hammer Mill for final size reduction.
Raw Material Conditioner
Once the raw material drops in the conditioner there are two drip tanks which can hold water and vegetable oil as well as other liquids. Small amounts of these liquids can be added to the raw material to either increase or reduce compression within the pellet mill die. The conditioner then mixes the raw materials and liquids consistently while metering the material into the die chamber.
Raw Materials and Productivity
The Mini Pellet Mill can process many different raw materials from wood, straws, grasses, energy crops and feed materials. We also have clients processing other unique and niche materials.
For wood pellets and other biomass pellets to be used as a fuel between 20-30 kg/h can be produced. For feed pellets up to 100 kg/h is possible depending on the diameter of the pellets.
Ring Die Design With Twin Rollers
The Mini Pellet Mill features a ring die design which is used by most commercial pellet plants, the majority of small pellet presses use the inferior flat die design.
The design of the Mini Pellet Mill also enables good access to the pellet die compression chamber for cleaning and maintenance. Four bolts secure the door which can quickly be removed as seen in the video above.
The ring die design produces pellets of a higher quality more consistently. It features reduced roller and die wear compared to flat die pellet mills and its is also more energy efficient. Material enters the center of the die from the conditioner above. The two rollers then compress the material through the die and they are cut to size with the adjustable knife.
Typical Mini Pellet Mill Customers
There are many multinational companies, national research centres and universities using this press for research and testing purposes in labs. We also have many clients using this press to produce pellets for market research before investment in a pellet plant and to help secure funding. There are a wide range of circumstances where the Mini Pellet Mill is good starting point for a pellet project.
The Mini Pellet Mill is manufactured here in the UK and we export around the world.
£4,995 + Delivery
If you would like a quotation on the Mini Pellet Mill for your project please complete the form below.
What is the price of the Mini Hammer Mill?
If you raw material requires size reduction before it can be used in the Mini Pellet Mill we also offer the Mini Hammer Mill as an additional tool. The hammer mill works on gravity and material flows from top to bottom and it mounted to a worktop. It has a 0.75kW single phase motor (240V/50Hz). The Mini Hammer Mill has a weight of 30kg and a productivity per hour of 10-100 kg/h depending on the raw material. We supply the Mini Hammer Mill with 3mm and 6mm screens. The price is £1,495 + Delivery.
Can you prepare a Mini Pellet Mill quote with delivery costs included?
Yes, as part of the quotation whether you are based in the UK or abroad we can prepare a Mini Pellet Mill quotation including delivery. We can quote door to door for either sea freight or air freight in most cases. If required we can also quote just to your closest sea/air port so you can arrange collection. If you have your own import agents that you would prefer to use we can also quote ex factory with just the packaging costs.
Is the Mini Pellet Mill suitable for making fuel pellets at home?
While the size and scale of the Mini Pellet Mill means it can be operated from home, its not a viable machine for the production of fuel pellets from home. The Mini Pellet Mill has a productivity per hour of 20-30kg/h for high density fuel pellets of either softwood, hardwood or other biomass materials such as straws and grasses. As the Mini Pellet Mill requires supervision of the process it means that producing 20-30 kg/h is not a viable use of the your time, as it also does not factor in the material preparation time and packaging of the pellets. There are many small pellet mills advertised on the internet as been suitable for producing pellets from home, however in reality in most cases its not a viable project.
Can the Mini Pellet Mill really make 100% hardwood fuel pellets?
Yes, the Mini Pellet Mill can take 100% hardwood sawdust which has been properly prepared and produce high density fuel pellets compatible to all of todays highest standards. To be properly prepared first the moisture content of the hardwood sawdust must be below 15%, generally 12% produces the best results. If the hardwood sawdust is too dry then the Mini Pellet Mill with its drip tank can add sufficient water into the process which is then mixed through the conditioner before it enters the compression chamber. The particle size of the hardwood sawdust must also have passed through a 5mm screen to be processed through a 6mm die. 6mm is the standard diameter for fuel pellets for the use in pellet stoves and boilers.
What about using pellet binders in the Mini Pellet Mill?
A powered binder such as modified corn starch at a 1-2% inclusion can make the process of making pellets a lot easier. For instance it can reduce the chance of die blockages and slightly increase the productivity per hour. It can also widen the moisture tolerance, so good pellets can be produced slightly outside of the ideal moisture zone. A pellet binder such a modified corn starch is commonly used in the pellet industry as processing aid.
Can the Mini Pellet Mill make pellets from paper and cardboard?
The answer to this question is technically yes, however its more difficult than processing other biomass materials and requires additional equipment. Where with biomass/wood a hammer mill is suitable for size reduction below 5mm, a hammer mill is not suitable for paper/cardboard. Once paper or cardboard is processed through a hammer mill the result is a very light fluffy material. The issue is that this material will not flow through the hopper on the Mini Pellet Mill or will get caught up in the feed auger/conditioner. Also once in the compression chamber this light fluffy material does not fall in the compression gap between the rollers and die consistently. The only way to process paper and cardboard with the Mini Pellet Mill is to use a cross cutting shredder which will produce small 5mm x 5mm squares which will then flow through the Mini Pellet Mill hopper and feed augers.
I have a range of biomass materials I need to trial, is the Mini Pellet Mill able to make pellets from a wide range of biomass?
If as part of your project you need to produce pellets from a wide range of biomass materials of different densities we can provide the Mini Pellet Mill with a low, medium and high compression 6mm die set. Along with the water and oil drip tanks fitted to the Mini Pellet Mill this will give you the flexibility to test a wide range of biomass materials and mixtures. A different compression ratio is achieved by manufacturing the die with a different inlet taper on the entry of the hole. The objective is to achieve a pellet of sufficient density without creating too much compression that the rollers cannot force the material through the die, which would lead to a blockage.
Can the Mini Pellet Mill be used to produce feed pellets?
Yes, in fact we can offer a wider range of pellet mill dies for the Mini Pellet Mill for feed pellet production compared to processing wood pellets in which we only offer the 6mm dies. For feed pellets we can offer the Mini Pellet Mill with dies as small as 2.8mm a scale up in various mm increments up to 8mm. Please note the Mini Pellet Mill can produce feed pellets for fish but they are only suitable for bottom feeding fish, as the pellets will sink.
Can grass and straw pellets be produced with the Mini Pellet Mill?
Yes, many different grass and straws can be made with the Mini Pellet Mill. Straws generally have a moisture content below 15% when properly stored, however with grasses the moisture content made need attention and drying. Examples of grasses include switchgrass, reed canary grass and miscanthus. Straws such as wheat and barley straw can also be processed however first the material must be processed through a hammer mill such as the Mini Hammer Mill to produce particles below 5mm.
Do any clients use the Mini Pellet Mill for production purposes?
Yes, while the low productivity per hour is not viable for producing standard grade wood pellets for fuel, there are other niche businesses that can still be profitable. For instance the Mini Pellet Mill could be used for the production of small volumes of custom feed/animal pellets that contain certain vitamins or supplements. It could also be the production of niche flavours and varieties of BBQ smoking pellets. In these examples the high value per kg of the pellets means the low productivity per hour of the Mini Pellet Mill is still viable.
Is the Mini Pellet Mill suitable for processing chicken manure waste/used horse bedding?
We get asked this question quite a lot and for good reason. Once processed into pellets chicken manure/horse manure can have a high value when properly packaged and sold to garden centres for instance as a soil conditioner. The Mini Pellet Mill can process chicken manure and horse manure as long as the moisture content is below 15% and the material has been reduced in size, for instance with the Mini Hammer Mill. This small press can be a good starting point to produce small volume of pellets in properly packaged branding to try and secure suitable distributors. With distributors on board this would make it a lot easier to secure the required finance for a pellet plant.