30 October 1998

Brushes gentle touch

BRUSH and star roller cleaning systems on harvesters are gentler on the crop than turbines and produce a cleaner sample, maintains Stephen Brown, project manager for British Sugars research and development department.

Perceived benefits of the concept seem to have caught the imagination of northern European growers.

Swedish manufacturers Thyregod demonstrated the system on an 8t capacity Standen-Thyregod T7 three-row trailed harvester. In stony soils, stone separation is carried out by a brush between the first and second webs.

For heavy conditions, the brush is replaced by three rubber primary cleaning rollers – with downward pressure and additional cleaning coming from an upper brush – which rotate clockwise to feed the beet to the cleaning elevator at the rear of the harvester.

To increase the degree of soil removal the operator can reverse the direction of rotation of the centre roller, which automatically reverses if, in the event of a blockage, hydraulic pressure rises above 170 bar for more than 10 seconds.

The cleaning systems are assembled in a cassette which, says Thyregod, enables a changeover time of around two hours.