Extreme Dust Protection: Jiwei Spin-11 Rotary Paddle Level Switch Achieves “Zero Intrusion” in Carbon Black Silos

Summary

This article details the application of Jiwei’s Spin-11 rotary paddle level switch in Hengfeng Carbon Black/Tire Manufacturing operations. The working condition involves ultra-fine, highly permeable carbon black powder under extremely harsh environments, where instrument housings are long-term covered and blackened by carbon dust. However, thanks to Jiwei’s innovative high-grade shaft sealing technology and the market’s highest-quality movement, the core bearings and internal movement remain completely free from dust intrusion during long-term operation. This outstanding dust-proof performance not only resolves long-standing instrument failure issues but also earns high trust from the customer, leading to large-scale repeat purchases.

I. Project Background and Extreme Condition Challenges

1. Industry and Material Characteristics

This case applies to the upstream processes of rubber/tire manufacturing—carbon black production and storage. As a key reinforcing filler in rubber products, carbon black presents extreme characteristics that pose stringent requirements on level measurement devices:

• Ultra-fine and highly permeable: Carbon black particle sizes typically range from nanometers to microns, far finer than ordinary dust, with strong “fluidization” tendencies and penetration capabilities that can breach standard instrument seals.
• High adhesion and abrasion: Carbon black easily sticks and accumulates, while its abrasive nature accelerates wear and failure of moving parts, especially bearings and shaft seals.
• Harsh environment: Production areas often experience high temperatures and humidity fluctuations, further aggravating carbon powder adhesion and instrument housing corrosion.

2. Pain Points of Traditional Instruments

Before adopting Jiwei products, most conventional rotary paddle switches used by the customer had the following issues:

• Bearing seizure and motor burnout: Dust penetration at the shaft or movement connection causes bearing wear, seizure, and eventual motor overload, with instrument life typically less than one year.
• Frequent maintenance and safety risks: Instruments required weekly or even daily cleaning, and frequent cover opening in dusty environments increased safety and explosion risks.
• False signals: Instrument failure prevented accurate material level detection, impacting downstream batching system automation and continuity.

II. Jiwei Spin-11 Rotary Paddle Level Switch Technical Breakthroughs

To meet the “zero intrusion” requirement for carbon dust, Jiwei’s Spin-11 series rotary paddle switches feature revolutionary sealing upgrades, ensuring absolute cleanliness of the internal movement under extreme conditions:

1. Core Sealing: Triple Labyrinth Shaft Seal Technology

To resist nano-scale carbon dust penetration, the Spin-11 employs a three-layer labyrinth shaft seal design:

• Layer 1 (core barrier): Precision labyrinth or high-quality mechanical seal prevents dust penetration under axial pressure.
• Layer 2 (external protection): Wear-resistant FKM lip seal acts as the first physical barrier against dust.
• Layer 3 (internal isolation): High-precision double-sealed grease bearings form the final barrier, completely isolating the movement from the external environment.

2. Internal Movement Isolation and High-Quality Components

• Highest-quality movement: Motor, gearbox, and circuit board use the market’s top components, selected and tested for ultra-low energy consumption, high stability, and long service life, ensuring reliability in harsh environments.
• Die-cast aluminum housing, IP65 protection: Movement is enclosed in a high-sealing aluminum housing, achieving IP65 protection against dust and water jets, keeping components dry and clean.
• High-torque drive: Custom high-start torque motor ensures reliable rotation even if blades are instantly buried in dense carbon powder, preventing overload damage.

III. Application Performance and Customer Value Validation

1. On-Site Operation

After installation, the Spin-11 switches operated long-term at the top and sidewalls of carbon black silos. The housings and blades became fully covered and blackened by thick carbon dust. Visual inspection suggested the instruments were heavily contaminated.

However, planned internal inspections revealed that core bearings and movement chambers remained clean as new, with zero dust intrusion. This validates the reliability of IP65 protection and the three-layer shaft seal under ultra-fine dust conditions.

2. Significant Economic and Safety Benefits

• Maintenance eliminated: Continuous, zero-failure operation, with routine inspection cycles extended from weekly to several months.
• Interlock safety ensured: Stable signal output guarantees accurate automatic feeding and low-level warning, preventing screw conveyor dry running and enhancing production continuity.
• Reduced operational costs: Extended instrument life (expected over three years) avoids downtime losses and high replacement costs.

3. Customer Trust and Large-Scale Repeat Purchases

Due to Spin-11’s exceptional performance and zero-intrusion reliability, the customer placed high trust in Jiwei products. Within a year, all traditional switches in existing silos were replaced with Spin-11, and the product was designated as the sole supplier for new production lines, resulting in multiple large-scale repeat purchases. This demonstrates the Spin-11 series’ industry-leading performance in high-penetration dust environments.

IV. Conclusion

The successful application of Jiwei Spin-11 rotary paddle switches in carbon black silos sets a benchmark for extreme dust-proof instrumentation. Through innovative and rigorous sealing design and top-quality movement, the instruments maintain internal cleanliness and stable operation even under the harshest conditions. This case provides a highly reliable, long-life solution for industries facing ultra-fine, highly penetrative dust measurement challenges.