Industry data: Standardized maintenance can reduce the failure rate from 23%
to 7% (statistics from China Mineral Processing Technology Association in
2025)
1. Core component defense system
1. Excitation coil protection (accounting for 52% of failures)
- Temperature monitoring: Embedded PT100 temperature sensor, set to
automatically reduce current at 65℃ (insulation life is halved for every 1℃
overtemperature)
- Moisture-proof treatment: Impregnate the coil with H-grade insulating paint
(such as silicone resin), and initiate heating and dehumidification when the
humidity exceeds 85%
- Overload prevention: Equipped with a current relay that immediately cuts
off power if the current exceeds 10% of the rated value
- Turn-to-turn detection: Measure inductance with an LCR meter monthly
(maintenance required if fluctuation >5%)
2. Stability maintenance of vibration system (accounting for 28% of
failures)
- Spring selection: 60Si2MnA material + shot peening (hardness HRC45-50),
with a stiffness deviation of <3%
- Dustproof sealing: Install a fluororubber dust cover (temperature
resistance -30~200℃), and clean the accumulated dust weekly
- Amplitude calibration: laser vibrometer detection (horizontal/vertical
amplitude difference < 0.2mm)
- Anti-loose upgrade: Apply threadlocker (such as Loctite 243) to the bolt,
and add a Belleville spring washer to the nut
II. Golden Rules for Daily Maintenance
1. Pre-shift inspection (a must-do item within 5 minutes)
- Coil temperature recording (alarm at ±5℃ compared to historical data)
- Measurement of spring compression (replacement if free height reduction
>3%)
- Clean the air-cooled filter screen (clean immediately if the pressure
difference exceeds 300Pa)
2. Weekly maintenance (30-minute key items)
- Magnetic pole cleaning: Use a copper scraper to remove adsorbed iron chips
(thickness > 2mm increases energy consumption by 15%)
- Insulation test: 2500V megohmmeter test (coil-to-ground resistance
>500MΩ)
- Bolt retightening: torque verification of critical parts (e.g., the exciter
bolt requires 80N·m)
3. Quarterly deep maintenance
- Bearing lubrication: filling with high-temperature lithium-based grease
(with the grease filling amount controlled at 30% of the cavity)
- Air gap calibration: adjust the parallelism of the magnetic pole surface
with a feeler gauge (error < 0.1mm/m)
- Dust removal of control cabinet: compressed air purging (pressure < 0.3
MPa)
III. Establishment of intelligent early warning system
1. IoT monitoring configuration
- Vibration sensor: installed on the bearing pedestal (frequency range
5-5000Hz)
- Temperature cloud map: infrared thermal imager scans coil hot spots (alarms
when temperature difference >8℃)
- Current harmonic analysis: Capture phase loss/grounding faults in
real-time
2. Three-level alarm mechanism
- Primary: Parameter out of range (SMS notification)
- Intermediate: deteriorating trend (automatic production reduction)
- Advanced: Emergency shutdown (e.g. vibration >12mm/s)
IV. Environmental adaptability transformation
1. High dust working conditions
- Positive pressure dustproof cabinet: Supply filtered air (pressure 500Pa)
to the control cabinet
- Labyrinth seal modification: The sealing level of rotating components
reaches IP65
2. High temperature environment (>40℃)
- Water-cooled coil: conductivity of circulating pure water <10μS/cm
- Ceramic insulation layer: Al₂O₃ coating with reflectivity >90%
3. Corrosive climate
- Stainless steel bolt: 316L material (as a substitute for carbon steel)
- Protective coating: polyurea elastomer (thickness ≥1mm)
V. Actual case of a quartz sand factory in Jiangsu
Problem background: The magnetic separator experiences 5 malfunctions per
month, resulting in downtime losses exceeding 380,000 yuan per year
Renovation measures:
1. Coil upgrade: H-grade insulation + intelligent temperature control
2. Vibration system: Install dust cover + adjust spring preload
3. Deploy IoT platform: real-time monitoring of current/vibration
achievements:
- The failure rate has decreased from 18 times per year to 2 times per
year
- Electricity consumption per ton of sand decreased by 0.7 kWh
- Awarded as a provincial intelligent manufacturing demonstration project
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conclusion
The stable operation of electromagnetic dry powder magnetic separators
requires triple safeguards: "human defense + technical defense + intelligent
defense":
1. Human defense: Strictly implement pre-shift inspection and weekly
maintenance
2. Technical defense: Upgrade of key components (coil/spring/seal)
3. Intelligent prevention: deploy predictive maintenance system