Roller graders

Roller-grader or roller-sizer

Grading using stainless steel rollers or tubes.

The turning rollers (tubes) carry the product from one side of the grader to the other and during this movement the distance between the rollers increases continuously. The results is that the smaller products falls between the rollers in the beginning and the biggest product comes out at the end.

Depending on your design you can classify 2 to 6 sizes. They are suitable for large and small capacities. The width of the equipment largely determines capacity.

Perpendicular under the rollers small conveyor belts are placed that receive the different sizes.

These conveyors can be bi-directional, that gives the possibility to choose which size comes out of the grader at which side.

An important advantage of this kind of sizers or graders is that they can easily be calibrated (size adjustment), even during operation.

The roller-sizer seen from above. The product leaves the inspection table and falls into the sizer. And the sizer drops the product, according to size, on the 4 bi-directional conveyors below the rollers.

A side view of the roller-sizer. This particular machine has an input capacity of 25 tons of potatoes per hour. The entry capacity is always the indicated as the capacity, because it is not known how many kilos leave each exit. That depends on the product, many small or many large.

The smooth gray area at the bottom of the picture is a soft material not to bruise the potatoes or onions as they leave the inspection table.