How does a pellet feed production line work

As the core equipment of modern animal husbandry and feed industry, the pellet feed production line achieves the maximum retention of raw material nutritional value and morphological reconstruction through systematic physical processing and thermodynamic treatment. This article will analyze the whole process of the production line from raw material pretreatment to finished product packaging from the perspective of engineering principles, focusing on the mechanism of action and parameter control points of key technical nodes such as ring die granulation, and provide professional analysis with practical reference value for industry technicians.

Overview of pellet feed production line

The modern pellet feed production line is an integrated system that converts powdered raw materials into high-density pellets through mechanical processing. Its core value lies in improving feed nutritional utilization and storage stability. The typical production line consists of four modules: raw material pretreatment, mixing and modulation, pelletizing and molding, and cooling and screening. The overall automation level can reach more than 90%.

Raw material pretreatment system

The first process of the production line uses a multi-layer cleaning screen and a magnetic separation device to remove impurities and metal objects from the raw materials, and a hammer mill controls the raw material particle size within the range of 1-2mm. Special attention should be paid to moisture regulation at this stage. Operators accurately control the moisture content of the raw materials at 15%-17% by adding steam to create the best plastic conditions for subsequent pelleting.

Mixing and modulation section

The twin-shaft paddle mixer achieves rapid mixing in 3-5 minutes at a speed of 60r/min, and the coefficient of variation CV≤5%. The conditioner uses 0.2-0.4MPa steam to increase the starch gelatinization degree of the material to 35%-45%. The temperature of this process needs to be stabilized in the range of 75-85℃. Professional production lines will be equipped with liquid addition systems. These systems enable precise spraying of trace ingredients such as oils and enzymes.

Ring die granulation core process

After modulation, the roller forces the material to pass through the ring die hole (common aperture 2-8mm) in the ring die granulator under its pressure. This process generates 60-90℃ friction heat, which denatures the material protein to form a bonding network. Key parameters include a die roller gap of 0.1–0.3 mm and a spindle speed of 200–400 r/min. The working current fluctuation does not exceed 15% of the rated value.

Post-processing and quality control

The countercurrent cooler cools the high-temperature particles to room temperature using ambient wind temperature plus 5℃. After cooling, the residual moisture remains at or below 12.5%. The multi-layer grading screen removes broken particles, ensuring the powder content of the finished product is less than 5%, and the automatic packaging system completes the 25–50 kg standard packaging. Technicians equip modern production lines with near-infrared detectors (NIR) to monitor protein, fat, and other indicators in real time.

Energy efficiency and intelligent development

Advanced pellet feed production lines have reduced power consumption to 25–35 kWh per ton of feed. Meanwhile, the steam consumption is about 60 kg per ton. The latest trend is to integrate the MES system to achieve automatic recipe switching, fault warning, and energy efficiency optimization. This enables the overall efficiency of the production line to increase to more than 92%.