Grain Optical Sorter

Short answer: A grain optical sorter feeds kernels in thin streams past high-speed cameras and blows out any particle that does not match the accepted colour or shape. The configuration depends on what you need to reject — colour defects alone, or foreign matter that looks like good grain — and on how much good product you can accept losing in the reject stream.

How it works

Grain enters a hopper and a vibrating feeder spreads it evenly onto inclined chutes. The kernels slide down in single layers and fall past an inspection zone where cameras, lit from both sides, capture each particle. Software compares what it sees with the sorting settings. When a particle falls outside the accepted range, a fast air ejector fires a short pulse and pushes it into the reject channel; accepted grain continues to the main outlet.

The machine depends on three things working together: steady, even feeding; clean viewing windows and stable lighting; and a reliable supply of clean, dry compressed air.

Which configuration fits

Form	Suits	Watch out for
Visible light	Rice, beans, seeds with colour or spot defects	Cannot easily separate foreign matter of similar colour
Visible light with near-infrared	Products where glass, stones or plastic are a concern	Higher investment; settings need careful validation

Sorting can be arranged in one pass or as a primary sort followed by a re-sort of the rejects, depending on defect rate and how much good grain you need to recover.

What we need from you to quote

• Grain type and typical kernel size
• Samples of accepted product and of each defect to remove
• Expected defect rate in the incoming grain
• Target throughput, stated on feed input per hour
• Acceptable carry-over ratio
• Compressed air availability and dust conditions at the installation site

Where it sits in a line

In a rice milling line the sorter usually sits after whitening and polishing, before packing. In a grain milling line it can follow cleaning to remove damaged kernels before grinding. Sorted grain then goes to bins and to a multihead weigher or bagging scale.