Pellet Machine for Aquaculture Fish Feed 0.5-5t/h | Supplier Guide
News 2026-07-06
Product Definition
A pellet machine for aquaculture fish feed is a ring die compaction system that converts fish meal, grains, protein concentrates, and oils into nutritionally balanced pellets for farmed fish and shrimp. The machine produces floating or sinking pellets with species-specific formulations, ensuring optimal growth rates and feed conversion ratios in aquaculture operations.
Technical Specifications & Performance Parameters
| Parameter | Value Range / Specification |
|---|---|
| Throughput capacity | 0.5 – 5.0 t/h (feedstock-dependent) |
| Main motor power | 55 – 160 kW (IE3 / IE4 compatible) |
| Ring die inner diameter | 400 – 800 mm |
| Pellet diameter | 1.5 – 12 mm (species-specific) |
| Pellet bulk density | 600 – 750 kg/m³ |
| Raw material moisture | 12% – 16% (optimal: 14% – 15%) |
| Specific energy consumption | 30 – 40 kWh/t |
| Pellet durability index (PDI) | ≥ 96% |
| Die service life | 700 – 1,000 hours |
| Roller shell service life | 500 – 800 hours |
| Maintenance man-hours | 4 – 6 h / month |
Structural Composition & Material Selection
The aquaculture fish feed pellet machine integrates four functional subsystems with defined material grades:
Mechanical System
- Ring die: Forged alloy steel (20CrMnTi) with carburised hardening layer (HRC 58–62)
- Roller shells: High-chromium cast iron (Cr26) with wear-resistant overlay
- Main shaft: Heat-treated 42CrMo4 steel with induction-hardened journals
- Gearbox: Helical-gear configuration, case-hardened to HRC 58–60
Support System
- Bearing housings: Ductile cast iron (QT600-3) with precision-machined seating
- Base frame: Welded structural steel, stress-relief annealed, with vibration-damping mounts
Lubrication System
- Centralised grease lubrication for bearings (NLGI grade 2)
- Forced oil circulation for gearbox (ISO VG 460) with temperature monitor
Control System
- PLC with HMI touchscreen for process monitoring
- Motor current feedback for load control
- Optional VFD for speed variation
- Extrusion/cooking control system for floating pellets
Manufacturing Process – Engineering Workflow
Step 1 – Ingredient Receiving & Grinding
Fish meal, grains, soybean meal, and other ingredients ground to ≤0.5–1.0mm (fine grind for aquafeed). Superfine grinding essential for small fish feed (1.5–3mm pellets).
Step 2 – Weighing & Mixing
Batch weighing system measures ingredients by formulation. Double-shaft paddle mixer ensures uniformity (CV ≤ 5%). Oil addition for energy density.
Step 3 – Conditioning & Cooking
Conditioner with steam injection at 0.3–0.5 MPa. Retention time 60–120 seconds. Mash temperature elevated to 85–100°C for starch gelatinisation and protein binding. Preconditioning for floating pellet expansion.
Step 4 – Pelletising (Core Forming Process)
Main motor drives ring die rotation at 4–7 m/s peripheral speed. Roller gap maintained at 0.10–0.25 mm. Pellet diameter determines die hole size. High compression for sinking pellets.
Step 5 – Counterflow Cooling
Ambient air drawn counter-current through pellet bed. Retention time 8–12 minutes. Pellet exit temperature ≤ ambient +5°C. Final moisture ≤10% for aquafeed stability.
Step 6 – Screening & Packaging
Vibrating screener removes fines. Product bagged or stored in bulk for aquaculture delivery. Minimal fines essential for water quality.
Industry Comparison – Aquafeed Pellet Options
| Feed Type | Pellet Size | Float/Sink | Ingredients | Typical Species |
|---|---|---|---|---|
| Shrimp Feed | 1.5–3mm | Sinking | High protein, marine meals | Shrimp, prawns |
| Starter Feed | 2–4mm | Floating | High protein, easy digest | Fish fry |
| Grower Feed | 4–6mm | Floating | Balanced protein | Tilapia, catfish |
| Finisher Feed | 6–10mm | Sinking | Energy-dense | Salmon, trout |
| Extruded Feed | 3–12mm | Floating | High starch | All species |
Differentiation (Shandong Changsheng Machinery):
Our aquaculture feed pellet mills produce high-quality pellets with PDI ≥96% – minimising fines and maintaining water quality. Multiple die sizes (1.5–12mm) accommodate all species from shrimp to salmon. Floating and sinking pellet options available through steam conditioning control. Stainless steel options for food-grade and corrosion protection from marine ingredients.
Application Scenarios by Buyer Role
Distributors / Importers
Focus on machine suitability for regional aquaculture species. Require floating/sinking pellet capability and fine-grinding options.
EPC Contractors
Integrating aquafeed production lines. Need hygiene, food safety, and water stability requirements.
Engineering Consultants / Technical Advisors
Evaluate aquafeed production and water quality impact. Require pellet stability and nutrient retention data.
End-user Production Facilities
Fish farms, shrimp hatcheries, and feed manufacturers. Demand water-stable, nutritionally complete pellets.
Core Pain Points & Engineering Solutions
Pain Point 1 – High water consumption and waste
Root cause: Poor pellet water stability – pellets disintegrate before consumption.
Solution: PDI ≥96% with proper conditioning. High shear and compression for water stability. Minimal fines reduce waste.
Pain Point 2 – Variable pellet size requirements
Root cause: Different life stages and species require different pellet sizes.
Solution: Quick-die change system enables rapid pellet size changes. Multiple die sizes available (1.5–12mm).
Pain Point 3 – Oil addition affecting pellet binding
Root cause: High oil content (10–20%) reduces pellet binding – crumbling during handling.
Solution: Post-pelletising oil coating. Proper conditioning for binding. High compression dies.
Pain Point 4 – Nutrient degradation from processing heat
Root cause: High processing temperatures degrade sensitive nutrients (vitamins, enzymes).
Solution: Optimised conditioning temperatures (85–100°C). Reduced dwell time. Heat-sensitive nutrients added post-pelletising.
Critical Risk Warnings & Mitigation Measures
Risk 1 – Fines causing water quality deterioration
Mitigation: PDI ≥96%. Gentle screening and handling. Dust extraction. Regular pellet quality testing.
Risk 2 – Mould growth in stored feed
Mitigation: Final moisture ≤10%. Clean storage conditions. Regular stock rotation.
Risk 3 – Salmonellosis risk from raw materials
Mitigation: Pathogen testing of ingredients. Proper heat treatment. Hygiene protocols.
Procurement Selection Guide – 7 Executable Steps
Step 1 – Identify aquaculture species and life stage
List species, pellet sizes (1.5–12mm), and floating/sinking requirements. Multiple sizes required for different growth stages.
Step 2 – Determine required capacity
Calculate feed requirement across species. Select model with 20% capacity margin.
Step 3 – Select die hole diameters
1.5–3mm (shrimp/starter). 4–6mm (grower). 6–10mm (finisher). 10–12mm (large fish).
Step 4 – Specify conditioning system
Steam conditioning for sinking pellets. Preconditioner with water addition for floating pellets.
Step 5 – Verify utility requirements
Power, high-pressure steam, and water. Confirm with site facilities.
Step 6 – Plan for food-grade hygiene
Stainless steel options. Food-grade lubricants. Clean-in-place capability.
Step 7 – Establish quality control
Moisture testing. PDI testing. Water stability testing. Nutrient analysis.
Engineering Case Study – Salmon Feed Mill in Norway
Project Background
A salmon feed mill in Norway produces 10,000 tonnes/year of extruded salmon feed (6–10mm sinking pellets). Mill expanded to produce trout and tilapia feed.
Initial Problem
Existing mill produced only one pellet size – limited to salmon feed. Clients demanded floating pellets and multiple sizes.
Root Cause Analysis
No ring die pellet mill with quick-change capability. Additional equipment required for floating pellet production and size flexibility.
Solution Implemented
Installed Shandong Changsheng aquafeed pellet mill (3.0 t/h capacity). Multiple die sizes (4mm, 6mm, 8mm, 10mm). Preconditioner for floating pellet production.
Final Data Results (12-month average)
| Metric | Before (Single Size) | After (Multi-Size Capability) |
|---|---|---|
| Pellet sizes available | 1 size | 4 sizes |
| Floating pellet capability | No | Yes |
| Market share (aquafeed) | 40% | 65% |
| Annual revenue | $8 million | $13 million |
| Quick-change die time | N/A | ≤45 minutes |
Frequently Asked Questions (FAQ)
1. What ingredients are used in aquaculture feed?
Fish meal, soybean meal, grains, oils, vitamins, minerals, and fish oils.
2. What pellet sizes are available?
1.5–12mm – customisable for different species and life stages.
3. What moisture is required for aquafeed pellets?
12% – 16%, with 14% – 15% optimal for pellet quality.
4. What is the typical capacity range?
0.5 – 5.0 t/h depending on model and feedstock.
5. Can I produce floating pellets?
Yes – with steam preconditioning and proper formulation. Floating pellets require expansion.
6. What is the difference between floating and sinking pellets?
Floating: lower density, higher starch, steam expansion. Sinking: higher density, higher protein, higher compression.
7. What is the durability of aquafeed pellets?
PDI ≥96% – essential for water stability and minimal waste.
8. Can I produce shrimp feed on the same machine?
Yes – with fine-grinding and 1.5–3mm die. Shrimp feed requires smaller pellets.
9. What is the specific energy consumption?
30 – 40 kWh/t depending on feedstock and pellet size.
10. What safety measures are required for aquafeed?
Food-grade hygiene. Pathogen testing. Contamination prevention. Regular quality testing.
11. What is the payback period?
Typically 18 – 30 months depending on production volume.
12. What is the shelf life of aquafeed pellets?
3–6 months if stored dry and cool (<12% moisture).
Author & E-E-A-T Credentials
Author: Dr. Chen Wei
Title: Senior Mechanical Engineer, Pelletising Systems Division
Experience: 14 years in biomass densification and feed processing equipment design
Notable Projects:
- Commissioned 6 aquaculture feed pellet lines across Norway, China, and Vietnam (2019–2025)
- Developed floating pellet production protocols and water stability optimisation
- Co-author of “Industrial Pellet Mill Maintenance and Optimisation” (Engineering Press, 2022)
Affiliation: Shandong Changsheng Machinery Co., Ltd.
