10 August 2001

How helical concave has helped out

A "HELICAL" concave designed to boost the outputs of Case Axial Flow rotary combines has proved to be successful after two seasons in the UK, according to Norfolk-based importer Defama.

Aussie background

Originally built for threshing crops grown in Australia, the concave is equipped with helically-arranged bars rather than the straight bars on the factory-fit Wide Wire concaves.

To give an aggressive threshing action at the start of the rotor, the helical concave replaces the front Wide Wire version, with the two other standard ones remaining in place.

The concave receives crop at 90í to the rotor which enables grain and straw to be separated more aggressively, says Defama.

Even discharge

Improved threshing is also claimed to allow a more even discharge of straw out of the combine and an even flow of grain onto the sieves.

This also enables the gap between the concave and rotor to be increased so rotor speed can be reduced, boosting throughput by 10%, claims Defama.

Further benefits of the helical concave are said to be less power requirement and greater threshing performance in a wide range of crops.

Price tag for the component is £608 and £714 for 60 and 80 series combines, respectively. &#42