Washing leafy greens: sand deserves special attention

Sormac conducted both theoretical and experimental research in its own laboratory on soil particles with a focus on how they can be removed and separated from the product. To assess the settling speed in water, grain size and a gentle flow are important. The latter is optimally achieved in a washing or transport flume. In food processing, a flume is a water-filled channel used to transport, wash, or cool fresh produce like vegetables and fruits. It gently moves products through different processing stages while helping to remove dirt and debris. A flume uses laminar flow where the fluid travels smoothly and steadily, with minimal mixing or turbulence.
 

Due to the long retention time and the laminar flow in the flume, the particles have time to loosen and settle. They are then removed via a so-called “sand trap.” In the case of very large amounts of sand, such as with products like lamb's lettuce, a pre-installed sand remover offers a solution.

Intensive research provided insight into how many particles of a certain diameter are removed in a flume of a certain length. The results of this research are used to optimise Sormac's washers and processing lines.

Both the Washing Flume WF and the Transport Flume TF from Sormac are very suitable for separating soil particles from the product.