Sugar Centrifuge and AC DrivesHeidi Ahola, ABB Industry Oy, Helsinki1/10Production Process (Beet)DiffusionSlicingWashingConveyorEvaporatingSUGARCookingCentrifugesFilteringPackagingConveyorPumpPumpPulp pressPulpSteam from Power PlantBeetThis symbol shows where an AC Drive would improve the process.Sugar IndustryCane sugar processCustomer needsAC Benefits2/10Operation principle Centrifuge separates particles from basic liquid The operation is cyclic, most motor power is needed for accelerating and decelerating Regenerative brake is neededCentrifuge3/10Speed Control What is actually being controlled? The processing sequence duty cycle Special requirements of the application? High inertia to be accelerated and decelerated Regenerative drive for the efficient braking Often a part of the multiple drive system Communication access to the process control system Demanding environment, no contamination allowedCentrifuge4/10Centrifuge process cycle1200RPM8004000kW300200100-100-200-300+-1342TimeSpeed (RPM)Power (kW)Sugar Industry55/10Centrifuge Reactive Power,AC Drive vs. DC Drive1200RPM8004000kVAr3002001001342AC kVarDC kVArDC Reactive Energy = 6.48 kVArhAC Reactive Energy = 0.74 kVArhTimeSpeed (RPM)Sugar Industry6/10Centrifuge Cycle Diagram1200RPM8004000kW300200100-100-200-300TimeCentrifuge N:o 1 2 3 4 5 6 1 Power/kW for Motor N: 1Total Power of 6 MotorsSpeed of Centrifuge N: 1Sugar Industry7/10Benefits of AC DrivesProcess Benefits Optimum centrifugal speed gives high production of the right quality Increased production capacity No harm from the dusty environment Low energy consumption with regenerative unit = Short Payback Time Centrifuge8/10Benefits of AC DrivesSavings Low active power Low reactive power Reduced Current and smaller cables because of Soft Start and regenerative unit No current peaks to the network Low maintenance costsCentrifuge9/10ReferencesCentrifuge10/10