FREQUENCY-CONVERTER CONTROLLED DRIVES FOR BATCHWISE PULPING

Measurements on high consistency and low consistency pulpers with elec tric drives controlled by frequency converters have shown considerable advantages over conventional drive concepts. Smooth start under lull load at high torque and low current, no torque impulses, no current pe aks and less wear. The pulping-process can by optimised by adapting it to the requirements of the processed material, - pulp or waste paper. A reduction of the final shive content and a reduction of the pulping time cause a higher production capacity oi the pulper. Considerable s avings in energy costs were achieved by operating at the minimum suita ble speed. Instalment of frequency converters in existing plants is ea sely possible and they can also be integrated into an existing process control system.