A simple matter of equilibrium…that’s the secret of the Stoner. Using the principle of stratification in a fluidized product bed, the Stoner has the special property of retaining an inventory of heavy fraction to prevent loss of product with rejects. Named for its original application, the Stoner was developed over 50 years ago to meet the special needs of flour mills requiring the removal of stones, metal and glass, which could not be removed by screening, from wheat.