Electromagnets have been used in industrial lifting applications for over a century. Their working principle and key components are well established. These consist of a ferrous core, fitted with pole shoes (polarities) at its extremities, and an electrical conductor winding, typically made of aluminum or copper, surrounding part of the core. When direct current flows through the winding, the magnet is energized, creating the lifting force.
SGM Electro Lifting Magnets are engineered for heavy-duty applications, featuring a high-permeability steel casing designed with significant safety margins. The bottom plate is made of wear-resistant manganese steel with an extra-heavy cross-section, ensuring durability and reliability even in demanding conditions.
The casing is fabricated using deep-welded submerged arc welding for maximum structural integrity. To optimize volume efficiency and heat dissipation, SGM windings are primarily manufactured with anodized aluminum strips, a material choice that enhances performance and extends the magnet’s operational lifespan.
Every element of SGM electromagnets is meticulously designed to maximize lifting capacity, mechanical strength, and thermal efficiency, setting new industry benchmarks for performance, endurance, and reliability.
How Industrial Electromagnets Work
The lifting force of an electromagnet depends on three key factors:
- Core Size & Geometry – A larger ferrous core provides greater lifting capacity.
- Number of Winding Turns – More turns in the winding result in a stronger magnetic field.
- Direct Current Intensity (Amperes, Idc) – Higher current increases magnetic force.
Once an electromagnet is manufactured, its core size and number of turns are fixed, while the current can be adjusted by regulating the direct voltage (Vdc). The electrical resistance (R) of the winding material also plays a role, as it increases with temperature, affecting current flow (Ohm’s Law: Vdc = R × Idc).
Heat Management in Electromagnets
Electromagnets generate heat due to electrical resistance (Joule effect), which impacts performance. The main factors influencing internal temperature are:
- Material Temperature – The temperature of the load being lifted, especially in hot applications.
- Duty Cycle – The percentage of time the magnet remains energized.
- Current Density – The level of electrical current passing through the winding.
- Winding Material – The thermal and electrical properties of the conductor.
SGM electromagnets are designed with conservative electrical density to optimize heat dissipation and ensure long-term efficiency. The use of anodized aluminum strips for windings further enhances cooling and performance stability over time.
Electro Lifting Magnets (EM): Key Benefits
- Versatility – Electro lifting magnets generate a deep and powerful magnetic field, making them ideal for a wide range of applications. They are particularly effective in situations where direct contact between the magnet pole shoes and the load is limited or where air gaps exist, such as handling ferrous scrap or structural steel bundles.
- Adjustable Force – The lifting force of an electromagnet can be fine-tuned by adjusting the voltage or current supplied to the magnet, providing flexibility in handling different materials.
- High-Temperature Applications – SGM electromagnets are suitable for handling hot materials up to 650°C (1,200°F), making them ideal for steel mills and foundries.
Electro Lifting Magnets (EM): Limitations
- Dependence on Continuous Power Supply – Electromagnets require a constant electrical current to maintain lifting force. To ensure safety in case of power failure, a battery backup system is recommended, along with proper protection and maintenance of power cables to prevent accidental disconnections.
