Abstract: A separator suitable for processing agriculture products in a fluidized bed flowing through an inclined trough under the influence of gravity. The fluidization medium is recirculated from the output end of the trough back to the input end thereof using a recirculation drum horizontally disposed laterally encircling the output end of the trough and supported for rotation about its own longitudinal axis. The inner surface of the drum includes an endless series of receiving pockets for collecting sand below the output end of the trough and lifting it thereabove. A damper at the output end of the trough is used to accelerate the establishment of the fluidized bed therein by temporarily obstructing the flow of fluidized bed. An ultrasonic sensor is used to determine the depth of the trough and based thereon to control the rate at which fluidization medium is provided thereto.