It’s not often that a game-changer comes along in nut processing, but one just has. This is the TOMRA 3C, a new optical sorting machine validated in field trials last year which achieves unrivalled sorting efficiencies and product yields.
Whereas mechanical sorters are well-suited to simpler sorting tasks, optical sorters offer even higher levels of accuracy, optimizing yields by reducing false rejects and enabling precise grading of the product, so that some rejected product can be retrieved for use. For these reasons, most large-volume processors use both mechanical and optical sorters, and now lower-volume processors are also adopting optical technologies. The arrival of the TOMRA 3C is an additional reason for progressing from mechanical to optical, and for upgrading from optical solutions that are not so effective.
The TOMRA 3C is superior to other, conventional optical channel sorters because it does not rely solely on double-sided RGB cameras, even though these (combined with high intensity, focused LED lighting) are powerful and effective. The crucial difference here is that the cameras can be complemented by either laser-detection or near-infrared (NIR) technology, to also examine the product according to structural and biological defects.
This unique combination of technologies enables the detection of product imperfections and contaminants even when defects’ colors are identical to those of good products. To give just one example of this, the color difference between good and poor brown hazelnuts is so small that cameras alone cannot detect it, meaning that, even if the shells are wanted, brown shells and brown stones may both get rejected.
The mechanical processes of the TOMRA 3C’s sorting system are quite straightforward. After produce falls from the hopper onto a shaker pan, it is spread evenly on the infeed chute. A few milliseconds after the product is inspected on both sides, the intelligent ejection system diverts defects into a reject chute and sends the good product on its way down the line via the accept chute.
The TOMRA 3C can be specified with two, three or four chutes of 500mm width. The option of having multiple numbers of chutes allows high throughput, but more than this, also offers great flexibility. While four chutes can be run in parallel to perform the same task to deliver extraordinarily high throughput (a 2000mm machine can handle 20 tonnes of inshell almonds per hour!), chutes can also operate independently from each other, meaning that processors can also choose, for example, to dedicate one or two chutes to the recovery lane or to reverse sorting.
This means that the TOMRA 3C can be located at different points on nut processing lines to fulfill different tasks – not only changing the game, but also able to play from different positions.