Analysis of milling operation with electro-hydraulic individual drives in the Ferrari Sugar Mill

The Ferrari Sugar Milltandem in Brazil is fully automated with variable speed for all the drives involved. The mills’ rollers are individually moved by electro-hydraulic drives (including the fourth roller in millone), thus offering a great advantage to automate the millin a very accurate way and to also measure the speed and torque in each of the rollers driven. The speeds and the torque of each roller of five four rollers mills tandem were registered continuously, providing information on the power consumed in each roller, in each milland in the whole tandem. The laboratory results were analyzed at the same time and the power consumption in the mills against the tonnage of fibre extracted was reported. Special attention was given to the possibility of changing the speed ratio of the fourth roll in relation to the top roll and measure the torque and power consumption, looking for the additional advantages of the corresponding individual drive. The operational results of the milling section of the factory were good, considering the size, number of mills and the crushing rate. Also, the power consumption in the mills was excellent for these conditions. The advantage of using the individual drive for the fourth roller in millnumber one was clearly observed during the season and the factory decided to drive all the fourth rollers individually in the near future.