In recent years, various retrofitting concepts have been used in drive technology. Usually new frequency converters are fitted – because a product is discontinued, because of a shortage of spare parts, or to increase throughput. One major factor today is also a high level of energy efficiency. To achieve this, aspects such as the drive motor, the locking system of batch centrifugals, the size of the basket load, and the efficiency of the converter all play an important role.
Optimum efficiency, higher throughput
In winter 2013, Südzucker in Ochsenfurt decided to upgrade their six BMA (G1750 type) centrifugals for white sugar. This involved, among other things, replacing the original control systems with up-to-date BMA automation technology. The integrated BMA DynFas FS measures the layer thickness in the basket, to ensure it is reached as precisely as possible. For the plant operator, this has the benefit that the converter and drive motor run at optimum efficiency. Excess capacities can result, so individual machines in the cluster can be shut down. An energy saver that reduces wear and tear in the long term.
The centrifugals' existing drive motors were replaced at the same time, with highly efficient state-of-the-art motors that were designed specifically for operation with converters. The frequency converters ensure that active power consumption is kept at an almost constant level. Another highlight is their maintenance-friendly design. With the use of more powerful drives, the batch rate per hour was increased, achieving a higher centrifugal throughput.
Lower energy costs thanks to sequencing
With higher-level BMA sequencing, interaction between all six centrifugals will in future be carefully coordinated. That will have an enormous impact, because electricity prices in many places are still based on peak demand. If the energy flow of all centrifugals in the cluster can be optimised with sequencing, peak loads and thus energy costs will be significantly reduced. A more even load profile for the centrifugals and, consequently, the whole factory will be the result. Electrical elements such as power units, compensation and switchgear will be exposed to less wear and tear.
Compared to traditional locking methods, the smart break management from BMA ensures smooth transportation of the finished sugar during maintenance of the centrifugal. This helps prevent overfilling of the sugar conveyors. With the visualisation of the sequencing, Südzucker now also has the flexibility to decide which of the two sugar transportation units should be used.
The centrifugal optimisation concept has caught on – and not only in Germany. Energy measurements taken in summer 2015 at a customer site in Brazil have also shown that state-of-the-art drive technology, the smart sequencing of processes, and the optimum basket load are key factors for efficient energy use. Smart energy management thus opens up unexpected opportunities for co-generation.