EMG eMASS^® – Electromagnetic strip stabilisation

EMG eMASS^® is a turnkey system based on electromagnets for the non-contact stabilisation of fast-running ferromagnetic steel strips. Therefore the main area of application is the homogenisation of continuous hot-dip coating with considerable savings potential.

Accordingly the benefits of EMG eMASS^® can be seen in all types of coating, such as zinc, zinc-magnesium, zinc-aluminium-magnesium, GALVALUME^®* and aluminium-silicon. It is usable with typical strip temperatures between 460 °C and 600 °C, and even optionally up to 650 °C to 700 °C for aluminisation.

It has been proven that a strip stabilised using EMG eMASS^® can be better manufactured with very thin coatings of less than 100 g/m² (100 gsm total). Similarly, advantages can be seen for very thick coatings of 400 g/m² (400 gsm total) and more, as required for the supporting structures of PV modules.

The system is usually installed directly above the air knife and as close as possible to the nozzle lip that blows off the liquid metal layer. With experience gained from over 80 successful installations worldwide, EMG guarantees customised, optimal integration of EMG eMASS^® in the nozzle area.    

*GALVALUME^® is a registered trademark of BIEC International Inc.

• Area of application: all ferromagnetic steel qualities at a strip temperature of < 600 °C, typ. GI, GF, GL;
  higher strip temperatures (e.g. for hot-dip aluminisation) are available on request & austenite content </=30 %, others on request
• Weight (total) (additional air knife load): typ. 900 kg per strip side, including brackets for inserting EMG eMASS^® into the carrier system (8 pairs of magnets at a max. strip width of 2100 mm)
  • Strip thickness: typ. 0.3–3 mm (others on request)
• Mechanics    
  • Dimensions with carrier (W x H x D): typ. 8500 x 840 x 950 mm for max. strip width of 2100 mm
  • Actuator housing: one air-cooled stainless steel housing with a heat protection shield on each strip side, temperature-resistant according specified strip temperatures
  • Time for assembly or disassembly with a crane: typ. 20 min including connectors and cooling air connection
• Electro magnetic actuator    
  • Force: max. 250 N at max. 20 A, typ. operating distance 20 mm (magnet: 35 mm) and 3 mm sheet thickness; max. strip temperature 600 °C
• Strip position sensor    
  • Sensor type: eddy current sensor system consisting of sensor head, sensor cable and measurement amplifier
  • Measuring range / resolution: 10-50 mm / ≤ 0,1 mm
• Cooling fan    
  • Cooling air fan with intake filter: motor rating: 2.2 kW
  • Dimensions (W x H x D): 625 x 700 x 1000 mm
  • Ambient temperature: max. 50 °C
  • Temperature of intake air: max. 50 °C
• Control cabinet components    
  • Power input: 3~, max. 18 kVA, nominal voltage, customer-specific
  • Power amplifier: special power amplifier with high control frequency > 100 Hz; max power dissipation: 50 W
  • Cable set: 2 sets of max. 7 cables each, partially in protective hose, max. length 50 m
  • Dimensions (W x H x D) / weight: typ. 3600 x 2200 x 600 mm / typ. 1000 kg

As the market leader with a large number of different integration solutions worldwide, EMG will find the optimal solution for you. The better the strip stabilisation system is combined with the air knife and the closer the strip stabilisation is located to the level of the air knife lips (i.e. the technology point), the better the results for vibration damping and crossbow reduction and the more manageable it is during regular plant stops. 

For example, the beams can be straight or offset in order to arrange the EMG eMASS^® magnet housing as close as possible to the nozzle lip in combination with the job-specific design of the supporting structure. Flexible adapters are available for individual situations. Depending on the respective air knife, its vertical and horizontal travel options and its load capacities, the support structure can be attached to the air knife, for example to the air knife height adjustment or to the factory floor. Versions with horizontal and vertical adjustment of the carriers or the actuator housings are possible. 

In addition to retrofitting EMG eMASS^® in this way into existing systems directly at the operator's premises, there are joint, combined solutions for modernisations and new systems with various suppliers of air knives. In particular, the ‘Integrated Solution’ with complete mechanical and electrical integration of EMG eMASS^® in the air knife has been offered and successfully used worldwide for many years in close cooperation with DUMA-BANDZINK GmbH. 

Further information about the integrated solution can be found here: DUMA-BANDZINK: Air-Knives and Integrated Solution.

• Homogeneous metal layer over strip width and strip length 
• Stable passline of the strip and reduction of the crossbow
• Narrower nozzle gap
• Targeted and reliable production of low run weights 
• Lower air or nitrogen consumption
• Higher strip speed 
• Better weldability 
• Avoidance of strip damage when used in the cooling tower 
• Saving potential for coating material due to reduced overcoating