JWZL-688 Vertical Pellet Mill – High-Moisture Biomass Processing

Project Summary

This installation features a Kingwood JWZL-688 vertical biomass pellet mill configured for processing high-moisture and complex biomass materials. The JWZL-688 is a 2-2.3 t/h capacity vertical ring die pellet mill from Kingwood’s standard product line, designed to handle feedstocks that present challenges for conventional pellet mills due to elevated moisture content or material variability.

The vertical ring die configuration positions the die perpendicular to the ground, with material fed from above and pellets extruded radially outward. This orientation simplifies die and roller maintenance compared to horizontal designs, as the ring die can be lifted vertically out of the pellet chamber without disassembling surrounding components. The transcript indicates the equipment is designed for “high moisture or complex materials,” suggesting the customer processes feedstocks such as agricultural residues, forestry waste, or mixed biomass streams that require robust pelletizing equipment.

The JWZL-688 incorporates several features addressing the operational demands of continuous industrial pellet production. A water cooling system enables extended run times without thermal shutdown, critical for facilities operating multi-shift schedules. The stainless steel pellet chamber resists corrosion from acidic or chemically active feedstocks, extending service life in applications processing materials like straw, bagasse, or bark. The nodular cast iron body and large gear quenching process reduce mechanical noise and vibration, contributing to stable long-term operation.

Equipment and Configuration

The JWZL-688 uses a top-range frequency conversion motor that outputs grid torque power, allowing the mill to maintain consistent pelletizing force across varying feedstock conditions. Four-bearing roller assemblies provide multi-layer mechanical protection, distributing loads and reducing the risk of catastrophic bearing failure during operation. An adjustable cutter mechanism allows operators to modify pellet length to meet customer specifications or optimize downstream handling characteristics.

A safety mechanical protection device is integrated into the drive system to prevent accidental damage from foreign objects or material jams. This feature is particularly relevant for operations processing field-collected biomass where metal fragments, stones, or oversized material may occasionally enter the feed stream despite upstream screening.

The JWZL-688 is part of Kingwood’s vertical pellet mill product line, which ranges from the 1-1.5 t/h JWZL-420 to larger models including the JWZL-928 (4-5 t/h). For procurement teams evaluating capacity requirements, the JWZL-688’s 2-2.3 t/h output positions it as a mid-range option suitable for regional pellet producers or captive fuel production facilities serving industrial boilers or district heating systems. Additional context on Kingwood’s vertical pellet mill range is available at /product/jwzl-928-vertical-biomass-pellet-mill/.

The transcript does not specify auxiliary equipment such as hammer mills, dryers, or coolers, but industrial pellet production typically requires integrated systems to achieve target moisture content (typically <10% for storage stability per ISO 17225 standards) and pellet temperature reduction before packaging.

Watch the Project

The video below shows the JWZL-688 installation and highlights key design features including the vertical ring die assembly, stainless pellet chamber, and four-bearing roller configuration.

Sources

• YouTube video QRQiQ7NPbOs (Kingwood site footage)
• IEA Bioenergy Task 40, “Biomass Pellet Production and Trade Statistics 2023”
• ISO 17225-2:2021, “Solid biofuels — Fuel specifications and classes — Part 2: Graded wood pellets”