에디 커런트 분리기: 작동 원리, 유형, 사양 및 선택 가이드
안 와전류 분리기 (ECS) recovers non-ferrous metals — aluminum cans, copper wire, brass fittings, zinc die-castings — from mixed waste streams by exploiting electromagnetic repulsion. If your recycling line processes municipal solid waste (MSW), auto shredder residue (ASR), electronic scrap, incineration bottom ash (IBA), or PET bottle flakes contaminated with aluminum closures, an eddy current separator is how you pull the non-ferrous value out. This guide covers the physics behind the technology, every ECS type Energycle offers, real operating parameters, and a step-by-step framework for specifying the right separator for your application.
What Is an Eddy Current Separator?
An eddy current separator is an electromagnetic sorting machine that separates non-ferrous metals from non-metallic materials on a conveyor belt. The core mechanism: a high-speed magnetic rotor spinning inside a non-metallic shell drum generates rapidly alternating magnetic fields. When conductive metals pass through these fields, electric currents (eddy currents) are induced inside the metal pieces, creating their own magnetic fields that oppose the rotor’s field. The resulting repulsive force launches non-ferrous metals forward off the belt, while non-conductive materials (plastic, glass, wood, paper) simply fall off the belt end by gravity.
The separation force depends on a material’s conductivity-to-density ratio. Aluminum (high conductivity, low density) separates most easily. Copper and brass (high conductivity but higher density) require stronger fields or slower belt speeds. Stainless steel and lead respond poorly to eddy current separation due to low conductivity or very high density.
How Does an Eddy Current Separator Work?
The working principle follows Faraday’s Law of electromagnetic induction and Lenz’s Law. Here is the step-by-step process:
1단계: 재료 공급
Pre-sorted material (ferrous metals already removed by magnetic drum or overband separator) feeds onto the ECS conveyor belt as a thin, uniform layer. A vibratory feeder upstream ensures monolayer distribution — stacked particles reduce separation efficiency by 30–50%.
Step 2: Magnetic Field Exposure
As material reaches the head pulley, it passes over the magnetic rotor spinning at 2,000–5,000 RPM inside a stationary shell. The rotor contains alternating N-S-N-S permanent magnets (typically NdFeB rare-earth) arranged around its circumference. This creates a rapidly changing magnetic field at the belt surface.
Step 3: Eddy Current Induction
When a conductive metal piece enters this alternating field, circulating electric currents (eddy currents) are induced within the metal. Per Lenz’s Law, these eddy currents generate their own magnetic field that opposes the external field — creating a repulsive (Lorentz) force that pushes the metal piece away from the rotor.
Step 4: Trajectory Separation
Three forces act on each particle simultaneously: (1) the eddy current repulsive force (forward/upward), (2) belt conveyor momentum (forward), and (3) gravity (downward). Non-ferrous metals, receiving the additional repulsive kick, follow a longer trajectory and land in the “metals” collection bin. Non-conductive materials simply drop off the belt end into a separate “non-metals” bin. An adjustable splitter plate between the two bins lets operators fine-tune the cut point.
Types of Eddy Current Separators
Different applications require different ECS designs. The main distinction is rotor geometry — concentric vs. eccentric — which determines the magnetic field pattern and optimal particle size range.
Concentric Pole Rotor ECS
The magnetic rotor is centered inside the shell drum. This produces a uniform, symmetrical field pattern ideal for standard recycling applications where particle sizes range from 20–150 mm. Concentric ECS units are the industry workhorse — used in MSW recycling, construction & demolition (C&D) waste, auto shredder residue, and general scrap processing. They offer reliable separation at high throughput with lower maintenance costs.
Eccentric Pole Rotor ECS
The magnetic rotor is offset (eccentric) inside the shell, creating an intense but localized field zone. This concentrates maximum magnetic energy at the separation point, making eccentric ECS units effective for fine particles down to 5 mm. Applications include IBA (incinerator bottom ash) processing, zorba/zurik sorting, WEEE (waste electrical and electronic equipment) recovery, and fine aluminum recovery from glass cullet. Our high-recovery ECS for fine aluminum uses this design.
High-Frequency ECS
Uses more magnetic poles (typically 18–30 poles vs. 12–16 on standard units) and higher rotor speeds to create rapid field alternation. This design targets the smallest non-ferrous particles (5–20 mm) where standard concentric units lose effectiveness. High-frequency ECS is essential for fine fraction processing in IBA plants, wire-chopping lines, and small WEEE recycling.
Wet Eddy Current Separator
Processes material in a water slurry rather than on a dry belt. Used where the feed is already wet (e.g., slag quench water, heavy media plant tailings) or where dust control is critical. Less common than dry ECS but necessary in specific metallurgical and mining applications.
Eddy Current Separator Type Comparison
| 유형 | Particle Size Range | 로터 속도 | Poles | 최고의 응용 프로그램 | 회수율 |
|---|---|---|---|---|---|
| Concentric (Standard) | 20–150 mm | 2,000–3,500 RPM | 12–16 | MSW, C&D, auto shredder, general scrap | 90–95% |
| Eccentric | 5–50 mm | 3,000–5,000 RPM | 14–22 | IBA, WEEE, zorba/zurik, fine aluminum | 85–93% |
| High-Frequency | 5–20 mm | 3,500–5,000 RPM | 18–30 | Fine fraction IBA, wire chopping, small WEEE | 80–90% |
| 젖은 | 5–80 mm | 1,500–3,000 RPM | 12–18 | Slag processing, wet mining tailings | 75–88% |
Key Operating Parameters
Five parameters determine eddy current separator performance. Optimizing these based on your specific material stream is the difference between 70% and 95% recovery rates.
1. Rotor Speed (RPM)
Higher rotor speed increases field alternation frequency and repulsive force — but only up to a point. Beyond the optimal RPM for a given particle size, performance plateaus or drops because particles receive too-brief field exposure. Typical operating range: 2,000–5,000 RPM. Start at 3,000 RPM and adjust based on recovery results. Fine particles need higher RPM; large aluminum cans separate well at lower speeds.
2. Belt Speed
Belt speed controls three factors: material burden depth (faster = thinner layer), dwell time in the magnetic field (faster = less exposure), and particle trajectory after separation. Optimal belt speed creates a single-particle-thick layer without stacking. Typical range: 1.5–3.0 m/s. Increase belt speed for high-throughput applications; decrease for fine-fraction recovery.
3. Splitter Position
The adjustable divider between metal and non-metal collection bins. Moving the splitter closer to the belt increases metal purity but reduces recovery; moving it further away increases recovery but allows more non-metal contamination. Set the splitter position based on whether your priority is maximum recovery (recycling revenue) or maximum purity (downstream process requirement).
4. Feed Layer Uniformity
The single most overlooked parameter. Stacked material blocks magnetic field access to lower layers, cutting recovery by 30–50%. Use a vibratory feeder to spread material into a uniform monolayer before it reaches the ECS head pulley. For wet or sticky material, install a pre-screening stage to remove fines that cause bridging.
5. Ferrous Pre-Removal
Ferrous metals (steel, iron) must be removed before the ECS. Steel pieces attract to the magnetic rotor shell, wrapping around it and damaging the belt, reducing non-ferrous separation effectiveness, and causing costly downtime. Always install a 자기 분리기 upstream — overband magnets, magnetic drums, or pulley magnets remove 99%+ of ferrous contamination.
Material Separation Performance
Not all non-ferrous metals separate equally. The governing factor is the conductivity-to-density ratio (σ/ρ) — higher ratios produce stronger separation forces. Here is how common materials rank:
| 재료 | Conductivity (MS/m) | Density (kg/m³) | σ/ρ Ratio | ECS Separation |
|---|---|---|---|---|
| 알류미늄 | 37.7 | 2,700 | 14.0 | Excellent — primary target metal |
| Magnesium | 22.6 | 1,740 | 13.0 | 훌륭한 |
| Copper | 59.6 | 8,960 | 6.7 | Good — needs slower belt or higher RPM |
| Brass | 15.9 | 8,500 | 1.9 | Moderate — larger pieces only |
| Zinc | 16.6 | 7,130 | 2.3 | 보통의 |
| Lead | 4.8 | 11,340 | 0.4 | Poor — density too high |
| Stainless Steel | 1.4 | 7,900 | 0.2 | Very poor — use sensor-based sorting |
This table explains why aluminum cans are the easiest material to recover with an ECS (highest σ/ρ ratio), while stainless steel requires sensor-based sorting technologies instead.
Specifications Reference
Energycle manufactures eddy current separators in working widths from 600 mm to 2,000 mm. Here are representative specifications across our range:
| 모델 | 벨트 폭 | 처리량 | 모터 파워 | 로터 직경 | 로터 속도 |
|---|---|---|---|---|---|
| ECS-600 | 600mm | 1–3 t/h | 4kW | Ø300 mm | Up to 4,000 RPM |
| ECS-800 | 800mm | 2–5 t/h | 5.5kW | Ø300 mm | Up to 4,000 RPM |
| ECS-1000 | 1,000 mm | 3–8 t/h | 7.5kW | Ø350 mm | Up to 3,800 RPM |
| ECS-1200 | 1,200 mm | 5–12 t/h | 11kW | Ø350 mm | Up to 3,800 RPM |
| ECS-1500 | 1,500 mm | 8–18 t/h | 15kW | Ø400 mm | Up to 3,500 RPM |
| ECS-2000 | 2,000 mm | 12–25 t/h | 22kW | Ø400 mm | Up to 3,500 RPM |
All models feature VFD (variable frequency drive) for rotor speed adjustment, NdFeB rare-earth magnets, replaceable non-magnetic shell, and adjustable splitter plate. Visit our eddy current separator product page for full specifications and configuration options.
산업 응용 분야
Eddy current separators serve every industry that needs to recover non-ferrous metals from mixed material streams:
Municipal Solid Waste (MSW) Recycling
In materials recovery facilities (MRFs), ECS recovers aluminum cans and other non-ferrous metals after magnetic separation removes steel. A typical MRF processes 20–50 t/h and recovers 95%+ of aluminum cans with a single ECS pass. The recovered aluminum generates $800–$1,500/ton revenue — often the highest-value stream in MSW recycling. See our complete MSW 분류기 lineup.
자동 파쇄기 잔류물(ASR)
After end-of-life vehicles are shredded, the mixed output contains aluminum engine parts, copper wiring, brass fittings, and zinc die-castings among plastic and glass. Multi-stage ECS processing (coarse fraction + fine fraction) recovers 85–92% of non-ferrous metals from ASR, adding $50–$120 per vehicle in recovered metal value.
Incineration Bottom Ash (IBA)
Waste-to-energy plant bottom ash contains 5–12% non-ferrous metals by weight — primarily aluminum and copper. Processing IBA through screening, magnetic separation, and eccentric/high-frequency ECS recovers metals worth €40–€80 per ton of ash processed. This application requires fine-particle ECS capability (down to 5 mm) due to the granular nature of IBA.
Electronic Waste (WEEE)
After shredding, e-waste contains copper, aluminum, brass, and precious metals mixed with plastic and circuit board fragments. ECS recovers the bulk non-ferrous metals; downstream sensor-based sorting or density separation further purifies the output. Typical recovery: 80–90% of aluminum and copper from shredded WEEE.
PET 병 재활용
Aluminum closures and rings must be removed from PET flake streams to achieve food-grade purity. An ECS positioned after crushing and washing removes 98%+ of aluminum contamination, bringing metal content below the 50 ppm threshold required for bottle-to-bottle recycling. Learn more about achieving ≤50 ppm metal in recycled pellets.
Construction & Demolition (C&D) Waste
Demolition debris contains aluminum window frames, copper pipe and wire, brass fixtures, and other non-ferrous metals. After primary crushing and ferrous removal, ECS recovers these high-value metals from the mixed aggregate, wood, and concrete stream.
Where ECS Fits in a Recycling Line
An eddy current separator never operates alone. Here is the typical position in a recycling line and the equipment it works alongside:
Typical processing sequence:
- 크기 감소 — shredder or crusher breaks material to processable size
- 상영 — trommel or vibrating screen separates material into size fractions
- Ferrous removal — 자기 분리기 (overband, drum, or pulley) removes steel and iron
- Eddy current separation — ECS recovers non-ferrous metals from remaining stream
- Further sorting — sensor-based sorting, density separation, or manual QC for final purity
For maximum recovery, many facilities use two ECS units in series: a concentric unit for the coarse fraction (>20 mm) and an eccentric or high-frequency unit for the fine fraction (5–20 mm). This dual-stage approach recovers 15–25% more non-ferrous metal than a single-pass system.
5-Step Selection Framework
Use this framework when specifying an eddy current separator for your operation:
Step 1: Characterize Your Feed Material
Identify the non-ferrous metals present (aluminum, copper, brass, zinc), their particle size distribution, percentage by weight in the feed, and moisture level. This determines whether you need a concentric, eccentric, or high-frequency ECS design and what recovery rate to expect.
Step 2: Determine Required Throughput
Measure your feed rate in tons per hour. The ECS belt width must handle this volume while maintaining monolayer feed distribution. A 1,000 mm belt handles 3–8 t/h depending on material bulk density; wider belts for higher throughput. Always size for peak capacity plus 20% margin.
Step 3: Choose Rotor Configuration
Concentric rotor for particles >20 mm (standard applications). Eccentric rotor for particles 5–50 mm (fine fraction, IBA, WEEE). High-frequency rotor for particles 5–20 mm (maximum fine-particle recovery). If your feed contains both coarse and fine fractions, plan for two ECS units in series.
Step 4: Verify Upstream Equipment
Confirm ferrous pre-removal is adequate (≤0.5% ferrous in ECS feed). Verify screening/sizing produces the correct size fraction for your ECS type. Ensure vibratory feeder or spreading conveyor is included for uniform monolayer distribution. Missing any upstream step significantly reduces ECS performance.
Step 5: Calculate ROI
Estimate annual non-ferrous recovery tonnage × metal value per ton = gross revenue. Subtract ECS operating costs (electricity, belt replacement every 12–18 months, rotor shell replacement every 3–5 years, maintenance labor). Most ECS installations achieve payback within 6–18 months based on recovered metal value alone — aluminum recovery at 95% rates generates $800–$1,500/ton revenue.
Maintenance and Troubleshooting
Eddy current separators are relatively low-maintenance compared to other recycling equipment, but regular checks prevent costly downtime:
| 간격 | 일 | 세부 |
|---|---|---|
| 일일 | Visual inspection | Check belt tracking, splitter position, and discharge areas for material buildup |
| 주간 | Belt tension check | Verify belt tension and alignment; misalignment causes uneven wear and reduced separation |
| 월간 간행물 | Bearing lubrication | Grease rotor and drive bearings per manufacturer schedule |
| 월간 간행물 | Shell inspection | Check non-magnetic shell for wear marks from ferrous contamination; replace if worn through |
| 분기별 | Magnetic field check | Verify rotor magnetic field strength with a gaussmeter — NdFeB magnets degrade <1% per year |
| 매년 | Belt replacement | Replace conveyor belt; inspect drive components, rollers, and bearings |
| 3–5 years | Shell replacement | Replace non-magnetic rotor shell (carbon fiber or stainless steel) when worn below minimum thickness |
Common issues and solutions:
- Low recovery rate → Check feed layer uniformity (most common cause), verify rotor speed matches particle size, inspect splitter position
- Metal in non-metal bin → Increase rotor speed, reduce belt speed, or move splitter further from belt
- Non-metal in metal bin → Decrease rotor speed, increase belt speed, or move splitter closer to belt
- Belt damage → Ferrous contamination reaching rotor; improve upstream magnetic separation
- Excessive vibration → Check rotor balance, bearing condition, and belt tracking alignment
Getting Started with Energycle
Energycle manufactures 와전류 분리기 in concentric and eccentric configurations with belt widths from 600 mm to 2,000 mm. We also provide complete sorting and recycling line integration including:
- Free material testing — send us a sample of your waste stream and we test separation performance on our ECS units
- Custom rotor configurations — pole count, magnet grade, and rotor speed optimized for your specific material
- Complete line design — from shredding through screening, magnetic separation, eddy current separation, and sensor sorting
- After-sales support — spare belts, replacement shells, remote troubleshooting, and on-site commissioning
재료 유형, 처리량 요구 사항, 원하는 출력 크기를 가진 with your material type, throughput, and target metal recovery — we will recommend the right ECS configuration and provide a detailed quotation within 48 hours.
자주 묻는 질문
How does an eddy current separator work?
An eddy current separator works by spinning a magnetic rotor at 2,000–5,000 RPM inside a non-magnetic shell drum. When non-ferrous metals pass over the rotor on a conveyor belt, the rapidly changing magnetic field induces eddy currents inside the metals. These eddy currents create opposing magnetic fields (per Lenz’s Law), generating a repulsive force that launches metals off the belt into a separate collection bin, while non-conductive materials simply fall off the end.
What metals can an eddy current separator recover?
Eddy current separators recover non-ferrous metals including aluminum (cans, extrusions, castings), copper (wire, pipe, fittings), brass, zinc die-castings, magnesium, and other conductive non-magnetic metals. Aluminum has the highest recovery rate (95%+) due to its high conductivity-to-density ratio. Copper and brass recovery is also good (85–92%) with proper rotor speed and belt speed optimization.
What is the difference between concentric and eccentric eddy current separators?
A concentric ECS has the rotor centered inside the shell, creating a uniform field ideal for particles 20–150 mm — the standard choice for most recycling applications. An eccentric ECS offsets the rotor to concentrate maximum field intensity at the separation point, enabling effective recovery of fine particles down to 5 mm. Choose concentric for general recycling; eccentric for IBA, WEEE, and fine-fraction applications.
What particle size can an eddy current separator process?
Standard concentric ECS units effectively separate particles from 20 mm to 150 mm. Eccentric and high-frequency models extend the lower range to 5 mm. Particles below 5 mm generally cannot be separated by ECS and require alternative technologies like electrostatic separation or wet gravity concentration. For best results, screen your material into size fractions and use the appropriate ECS type for each fraction.
How much does an eddy current separator cost?
Small ECS units (600 mm belt width, 1–3 t/h) start around $15,000–$25,000. Mid-range models (1,000–1,200 mm, 5–12 t/h) cost $30,000–$65,000. Large industrial units (1,500–2,000 mm, 12–25 t/h) range from $70,000–$150,000. Most installations achieve payback within 6–18 months from recovered metal value — a facility recovering 100 kg/h of aluminum generates $80,000–$150,000 annual revenue at current market prices.
Why is ferrous removal needed before an eddy current separator?
Ferrous metals (steel, iron) are attracted to the ECS magnetic rotor rather than repelled. They wrap around the shell, damaging the belt, blocking non-ferrous metal separation, and requiring costly emergency shutdowns for removal. Always install magnetic drums, overband magnets, or pulley magnets upstream to remove 99%+ of ferrous metals before the ECS.
Can an eddy current separator recover copper?
Yes, but copper is harder to separate than aluminum due to its higher density (8,960 kg/m³ vs. 2,700 kg/m³ for aluminum). Despite copper’s excellent conductivity, its lower conductivity-to-density ratio means the repulsive force relative to gravity is weaker. Optimize copper recovery by using slower belt speeds, higher rotor RPM, and an eccentric rotor design. Expect 85–92% copper recovery with proper optimization.
What maintenance does an eddy current separator require?
Daily: visual inspection of belt tracking and discharge. Weekly: belt tension check. Monthly: bearing lubrication and shell wear inspection. Annually: belt replacement. Every 3–5 years: rotor shell replacement. NdFeB magnets degrade less than 1% per year and typically last 15–20+ years. Total annual maintenance cost is typically 3–5% of equipment purchase price — far lower than most recycling machines.
