German Swine Feed Manufacturer Achieves 10 TPH Consistent Pellet Output with Hongyang SZLH508 Ring Die Pellet Mill

Executive Summary

A mid-sized swine feed manufacturer in Lower Saxony, Germany  a region producing approximately 30% of the country’s pig feed commissioned Hongyang Machinery’s SZLH508 ring die pellet mill in early 2025 as part of a production line modernization. After eight months of continuous operation, the mill has sustained 10 metric tons per hour (TPH) output with a Pellet Durability Index (PDI) consistently exceeding 96%, while energy consumption decreased by 12% compared to the previous flat-die system. This case study documents the selection criteria, installation process, and performance data from the first 240 days of operation, offering a reference point for European feed mills evaluating ring die technology upgrades.

1. Industry Context: German Swine Feed Production

Germany is the largest pig producer in the European Union, with approximately 21.2 million pigs in inventory as of November 2023 (Statistisches Bundesamt, 2024). The country manufactures over 24 million tonnes of compound feed annually, of which swine feed accounts for roughly 38% — approximately 9 million tonnes (FEFAC, 2024). Lower Saxony and North Rhine-Westphalia collectively host more than 60% of the nation’s finishing pig population, making this corridor the most concentrated swine feed consumption zone in Europe.

The German compound feed sector operates under stringent regulatory frameworks: the EU Feed Hygiene Regulation (EC No 183/2005), the German Feedstuffs Ordinance (FuttMV), and the QS Qualität und Sicherheit GmbH certification system. Pellet quality  measured primarily by PDI and fines percentage  is not merely a commercial preference but a compliance parameter linked to animal welfare outcomes and nutrient digestibility benchmarks.

German feed mills have historically sourced pelleting equipment from domestic and other European manufacturers. However, rising capital expenditure and extended lead times for European-made ring die pellet mills have prompted a segment of mid-tier producers to evaluate Asian alternatives that can deliver comparable performance metrics with shorter delivery windows.

2. The Client Profile and Operational Challenge

The client  referred to here as “Betrieb M” for confidentiality  operates a single-line swine feed mill near Oldenburg in Lower Saxony, serving 12 contract finishing farms and three farrow-to-finish operations within a 60-kilometer radius. Annual output before the upgrade was approximately 28,000 tonnes, covering six pellet diameters (2.5 mm to 4.5 mm) across four formulation types: starter, grower, finisher, and lactating sow.

Prior to 2025, Betrieb M operated two concurrent flat-die pellet mills, each rated at 5 TPH but rarely achieving more than 4.2 TPH in sustained production. The principal challenges were:

1. Output instability: Throughput fluctuated by ±18% across shifts due to die wear progression, requiring operators to frequently adjust conditioner steam injection and feeder speed. An internal audit in Q3 2024 recorded 62 unplanned downtime events over 90 days, of which 41 were attributable to pellet mill blockages or motor overload trips.

2. Inconsistent pellet quality: PDI values  measured using the Holmen NHP100 tester per ISO 17830  averaged 92.3% for 3.5 mm finisher pellets, below the QS recommendation of ¥ 95% for swine feed. The mill’s nutritionist reported that fines content at the farm bin averaged 4.8%, leading to feed sorting behavior observed in grower pigs and a 1.7% increase in feed conversion ratio (FCR) compared to pellet samples tested directly at the mill gate.

3. Energy intensity: The flat-die configuration consumed 18.2 kWh per tonne of pelleted feed (measured at the main drive motor), which management considered 10-15% above the industry benchmark for ring die systems of equivalent capacity (FEFAC compound feed production benchmark data, 2023).

4. Maintenance overhead: Die and roller replacement cycles averaged 800-1,000 operating hours, translating to approximately 10 die changes per year per mill. Each changeover required 3.5-4 hours of downtime for cooling, disassembly, replacement, and recalibration.

3. Equipment Selection and Technical Rationale

Betrieb M issued a request for quotation (RFQ) in mid-2024 to six equipment suppliers three European and three Asian. The evaluation criteria were weighted as follows: sustained throughput (30%), pellet quality consistency (25%), energy efficiency (20%), total cost of ownership (15%), and delivery/commissioning timeline (10%).

Hongyang Machinery’s SZLH(HYPM)508 was selected after a comparative trial conducted at Hongyang’s Changzhou demonstration facility in September 2024, where Betrieb M shipped three tonnes of its own finisher formulation (corn-soybean meal based, 14.7% crude protein, 3.9% crude fiber) for test pelleting. The SZLH(HYPM)508 achieved:

- Average throughput: 10.3 TPH over a 4-hour continuous run (die: 4.0 mm  70/70 mm effective thickness, compression ratio 1:8.5)

- PDI: 97.1% (Holmen NHP100, 60-second test)

- Specific energy consumption: 15.6 kWh/tonne at the main drive

The SZLH(HYPM)508 is a belt-driven ring die pellet mill with a 508 mm internal die diameter, 160 kW main motor, and a dual-motor forced feeder configuration. Its key differentiators included a stainless steel conditioner with a 2.5-meter retention length providing 45-90 seconds of conditioning time (adjustable via paddle angle), a pneumatic die hoist system enabling single-operator die changes in under 40 minutes, and an automatic lubrication system with programmable grease intervals synchronized to operating hours and tonnage.

The total installed solution consisted of: SZLH(HYPM)508 ring die pellet mill, HYSC-3.0 twin-shaft paddle conditioner, HY-FD2000 forced feeder, and an integrated PLC control panel with Modbus TCP communication to the plant’s existing SCADA system. The installation was completed in February 2025 during a scheduled 5-day maintenance window, with Hongyang dispatching two commissioning engineers for on-site supervision, alignment, and load testing.

4. Operating Results: January-August 2025

After the commissioning phase (first 30 days, with throughput gradually ramped from 6 to 10 TPH), production data for the subsequent seven months (March-September 2025) were compiled by Betrieb M’s quality assurance department. The following table summarizes key performance indicators:

The most significant improvement from the nutritionist’s perspective was the sharp reduction in fines at the point of consumption. Betrieb M’s internal trial on a 400-head grower barn (25-60 kg body weight, 42-day period) reported an FCR of 2.38 with SZLH508-produced pellets, compared to 2.44 with the previous pellet supply  a 2.5% improvement. While acknowledging that multiple variables influence on-farm FCR, the nutritionist attributes a measurable portion of this gain to reduced feed wastage from sorting behavior.

Energy savings of 2.8 kWh per tonne, multiplied by annual production of approximately 28,000 tonnes, yielded an estimated annual saving of 78,400 kWh  equivalent to roughly 31 tonnes of CO2 under Germany’s 2024 electricity grid emission factor of 0.395 kg CO2/kWh (Umweltbundesamt, 2024). At an industrial electricity rate of approximately ¬0.18/kWh in Lower Saxony, this represents a direct cost reduction of over ¬14,000 per year.

5. Operator Experience and Maintenance Feedback

Betrieb M’s maintenance supervisor reported that the pneumatic die hoist system reduced die changeover time from the previous 3.5-4 hours to approximately 35-45 minutes, with a single operator and one assistant. The automatic lubrication system eliminated a daily grease schedule of eight manual points per machine, replacing it with a bi-weekly cartridge check.

The plant manager noted that the Modbus TCP integration with the SCADA system provided real-time visibility of motor current, bearing temperatures, conditioner steam pressure, and die temperature  parameters that were previously monitored only through periodic manual readings. This data stream has enabled the QA team to correlate pellet quality fluctuations with specific process deviations, reducing the root-cause analysis time for quality incidents from approximately two hours to 15 minutes.

Two areas for future improvement were identified: first, the client requested a direct coupling drive variant (in place of the belt-drive) for a potential second line expansion, citing perceived marginal efficiency gains at the belt transmission; second, the operator interface language was initially set to Mandarin, requiring Hongyang’s remote support to switch to English. Hongyang has since updated the HMI firmware to default to English for European deployments.

6. Conclusion

The Betrieb M deployment demonstrates that a modern ring die pellet mill from an Asian manufacturer can meet the throughput, pellet quality, and reliability requirements of German compound feed production when the equipment is properly specified for the formulation and operational context. Key success factors included pre-purchase trial pelleting with the client’s own feedstock, thorough on-site commissioning support, and a PLC architecture compatible with existing plant automation.

For mid-tier European feed mills facing capacity constraints or aging pelleting assets, Hongyang’s HYPM series represents a cost-effective modernization pathway with documented performance data now available from a German reference site. The 8-month dataset presented here  while limited in duration compared to a multi-year evaluation covers sufficient operating hours to provide a meaningful baseline for PDI stability, energy consumption, and maintenance burden.

Hongyang Machinery continues to collect operating data from this installation at quarterly intervals and will publish updated findings as the equipment accrues additional service years.