28 November 2012 – The Zest WEG group recently commissioned an installation at a sugar mill in Mozambique that has led to improvements in centrifuge performance and achieved significant energy savings.
The scope of supply included three 132 kW squirrel cage electric motors from WEG`s W22 range and three WEG AFW11 variable speed drives with an active front end to drive the mill’s centrifuges. The drives supplied are equipped with a regenerative unit that regenerates energy back to the supply under braking conditions and the design of the motors was also customised to avoid any change on the existing installation.
The mill’s existing motor had external cooling and additional 18.5 kW motors were used to draw clean air in from the outside atmosphere for this purpose. The solution provided by Zest Weg eliminated the need for this external cooling system, saving energy
Although it has successfully completed several installations in the sugar sectors of other African countries, this is the first project of its kind to be carried out by Zest WEG in Mozambique.
In addition to a 30% improvement in productivity, the quality of the sugar from the new centrifuges also improved at the mill. The existing system had taken too long to slow down and the sugar had dried out more, creating a caking effect. With the new system, the mill operating team has more flexibility and control over the drying times.
The installation, fully customised to integrate with existing technology, was installed and commissioned within a week to ensure minimum downtime on the production process.
At the same time, the Zest WEGgroup team installed an 800 kW motor in another area of the mill to control the cane cutter and a 1.8 MW slip-ring motor to power the cane shredder.