A New Paradigm in Clean Conveyance: The Critical Application of Stainless Steel Horizontal Feeders in High-End Aquafeed

1. Application Background and Production Challenges
A certain aquafeed production line is responsible for manufacturing extruded floating pellets, using a mixture of fish meal, soybean meal, and oils (moisture content 12%–14%, containing trace amounts of salt and acidic oils).
The existing screw feeders had three major shortcomings:
① The carbon steel housing was corroded by acidic oils, resulting in rust spots that caused iron ion contamination in the raw materials (test results exceeded national standards by 30%), which affected the feed’s color and palatability;
② Gaps between the screw blades became clogged with wet material, causing the screw to seize, requiring the line to be shut down for cleaning four times a month;
③ Frequent fluctuations in feed rate caused torque deviations in the extruder exceeding 10%, resulting in a pellet uniformity pass rate of only 86%.

2. Equipment Selection and Customized Design
A 304 stainless steel horizontal feeder was selected, with the following optimized configuration:

Conveying Structure: Stainless steel scraper chains paired with U-shaped wear-resistant guide rails, with scraper spacing reduced to 200 mm to prevent slipping and accumulation of oily materials;

Drive Control: Installation of load cells linked to a variable frequency drive (VFD) to monitor material layer thickness in real time and automatically adjust speed, with a response time of ≤0.5 seconds;

Residue Prevention: The interior of the housing features mirror-polished surfaces (Ra ≤ 0.8 μm), and a pneumatic gate is installed at the tail end to automatically close during shutdown, preventing oil dripping and material clumping.

3. Operational Results and Data Comparison

Quality Improvement: Iron ion content in feed decreased from 180 ppm to 22 ppm; the expansion rate of extruded pellets increased from 89% to 96%; and the sinking rate is <3%;

Efficiency Improvements: Feeding accuracy stabilized at ±1.5%; torque fluctuations in the extruder narrowed to ±3%; continuous operation cycles extended from 7 days to 45 days;

Simplified Maintenance: Wear on stainless steel slideways is only 1/5 that of carbon steel; daily maintenance requires only 10 minutes of high-pressure water jet cleaning of the inner walls per shift, reducing annual labor hours for maintenance by 120 hours.

4. Implications for the Industry
This case study demonstrates that stainless steel horizontal feeders, when used to convey feed ingredients containing fats and salts, not only mitigate the risk of metal contamination but also resolve the challenge of “bridging” in viscous materials. They provide a clean, stable, and long-cycle conveying solution for the production of high-quality aquatic feed, making them particularly suitable for premixing and conditioning processes with strict hygiene standards.