2026/07/16
In the industrial production system for organic fertilizer, the half-wet material crusher, twin-screw windrow turner, and double-roller extrusion granulator form a core three-stage equipment assembly covering everything from raw material pretreatment to finished granule formation. The process integration and parameter matching among these three units directly determine the production line's output efficiency and product quality stability.
The fermentation stage marks the beginning of the production line, where the twin-screw windrow turner plays an indispensable role in driving aerobic fermentation. Designed specifically for trough-style fermentation, this equipment utilizes a counter-rotating dual-shaft mechanism; two main shafts equipped with continuous spiral blades rotate synchronously in opposite directions, generating powerful shearing and lifting forces on the material within the fermentation trough. With a turning depth of 1.6 to 1.8 meters and a span covering 6 to 12 meters, the machine significantly enhances space utilization within the fermentation workshop. During the turning process, the twin-screw turner lifts anaerobic material from the bottom of the trough to the surface for full contact with air, providing ample oxygen for aerobic microbial proliferation while simultaneously breaking up material clumps and forcing the release of free moisture. This process shortens the traditional 60-to-90-day fermentation cycle to just 7 to 15 days and boosts nitrogen retention to over 85%. Even after full decomposition, the fermented material retains a high moisture content (25% to 50%) and contains significant fibrous matter and clumps; consequently, it must undergo fine processing in a half-wet material crusher before proceeding to the next stage.
The half-wet material crusher serves as the critical link connecting the fermentation and granulation stages. This equipment features a structural design utilizing two-stage rotors operating in series. Material first enters the upper-stage rotor crushing zone, where high-speed rotating hammers shatter it into fine particles. It is then propelled into the lower-stage rotor crushing zone for further fine pulverization; simultaneously, the particles collide and grind against each other at high speeds within the chamber—achieving an optimal "hammer-on-material" and "material-on-material" crushing effect—before the resulting fine powder is discharged directly from the outlet. Unlike conventional crushing equipment, this half-wet material crusher is designed without a bottom screen, fundamentally resolving industry-wide issues such as clogging, wall adhesion, and poor discharge flow caused by wet materials. It accommodates a wide range of moisture content for bio-fermented organic fertilizer materials, handling levels between 25% and 55%. The finely crushed material is uniform in texture, loose, and breathable; this effectively improves the subsequent granulation rate and prevents issues such as uneven particle size or crumbling caused by material clumping.
The finely crushed material then enters the granulation stage, where a double-roller extrusion granulator completes the transformation from powder to granules. This equipment employs a dry extrusion process, utilizing a pair of counter-rotating, high-strength rollers with regularly arranged arc-shaped grooves on their surfaces. After being evenly fed into the gap between the rollers by a forced feeder, the material undergoes plastic deformation under an extrusion pressure of 50 to 150 MPa and is pressed into the roller grooves to form a dense sheet or "cake." Upon release from the rollers, this sheet undergoes crushing, granulation, and screening to yield high-density, high-strength finished granules. The entire process requires no added water, heating, or drying, thereby eliminating the drying and cooling steps essential to traditional wet granulation and reducing energy consumption by 30% to 50%. The double-roller extrusion granulator has strict requirements regarding raw material moisture content—specifically 18% to 22% for organic fertilizer—which aligns perfectly with the moisture levels of material processed by the half-wet material crusher. The precise coordination of process parameters across three pieces of equipment—with the windrow turner controlling fermentation maturity, the crusher regulating fineness and moisture content, and the granulator managing molding pressure and granule strength—forms a complete technical closed-loop for the dry production of organic fertilizer, offering a highly efficient, energy-saving, and eco-friendly systematic solution for the resource utilization of organic waste.
