The demand for wood pellets and other biofuels is growing steadily, driven by high energy prices and the desire for climate-friendly alternatives. However, before wet wood chips can be turned into standardized pellets, one crucial step must be taken: crushing. This is where AMANDUS KAHL’s pan grinder mill comes into play, providing an obvious efficiency boost right from the outset.
The production of wood pellets involves a series of processing steps. The pan grinder mill can handle fluctuations in product properties and reliably crushes coarse raw materials, such as wood chips, up to size G50, even when they contain up to 60 percent moisture. The centerpiece of the machine is the combination of pan grinder rollers and die. Thanks to the crushing and shearing action, particles are produced that are smaller and better suited structurally to the subsequent processing steps. Thus, difficult-to-process raw material is transformed into a perfectly prepared starting product, forming the basis for energy-efficient pellet production.
Wood crushing in detail: How the pan grinder mill works
Compared to traditional wet mills, the pan grinder mill offers a number of process-related advantages. It defibrates wood in a more uniform and energy-efficient manner, transversely to the fiber direction. While a hammer mill breaks wet wood chips into long, needle-like structures, a pan grinder mill produces significantly shorter particles with pre-damage in the fiber direction.
The vertical product supply into the pan grinder mill ensures the generously sized grinding chamber is uniformly filled as the product falls freely. This eliminates the need for forced feeding and allows large volumes of product to be processed smoothly and without blockages. Intense shear forces act between the pan grinder rollers and the die, defibrating the product to a defined particle size.
Pan grinder mills use flat dies, which have a smaller bore length-to-diameter ratio than flat-die pellet mills. This prevents unnecessary friction in the bores. Consequently, the particles are defibrated, not compacted. The result is a homogeneous particle structure achieved with minimal energy consumption.
With a circumferential roller speed of just 2.5 meters per second, the pan grinder mill operates with minimal vibration and noise. There is no need for explosion protection measures inside the machine, nor for complex equipment such as cyclone, filter, fan and exhaust air system.
From wood chips to standard-compliant pellets
DThe advantages of using a pan grinder mill for crushing become apparent in practical pellet production. Not only does the pan grinder mill make the entire pelleting process more efficient, but it also makes it less complex. The resulting particle structure is more homogeneous, making it better suited for producing standard-compliant pellets. For the production of domestic fuel pellets, the dry grinding process that usually follows drying is unnecessary, as the particle structure achieved with the pan grinder mill is already suitable for further processing.
Using the pan grinder mill in combination with the flat-die pellet mill from AMANDUS KAHL makes the overall process particularly energy-efficient because it can process coarser particle structures into standard-compliant pellets.
Higher performance with lower energy consumption
Using a pan grinder mill rather than a dry hammer mill in the production line reduces the amount of electrical energy required for wet grinding and pelleting by up to 35 kWh/t, depending on the bore diameter of the die. These savings add up to several thousand megawatt hours per year, which is a significant cost factor in pellet production, particularly when production volumes are high.
AMANDUS KAHL manufactures twelve different sizes of pan grinder mills with throughput rates of up to 30 t/h and a power range from 30 to 600 kW. Therefore, the machine manufacturer's product portfolio is suitable for both smaller plants and large-scale industrial projects.
Conclusion: The pan grinder mill ensures efficient and sustainable wood pellet production
The pan grinder mill is a key component of an energy-efficient production chain, transforming coarse, moist wood chips into a structurally homogeneous product and optimizing the entire process all the way to the finished wood pellet.
For operators of wood pelleting plants, this means fewer process steps, lower energy consumption, and reduced operating costs. With 150 years of experience in mechanical and plant engineering, AMANDUS KAHL offers a solution that combines technology, economic efficiency, and sustainability.
