The invention provides a sorting and grading device of a pulsating liquid-
solid fluidized bed and a method thereof. The sorting and grading device comprises a light product overflow trough, a central feed
pipe, a sorting tank, a pulsating liquid
distributor, a pulsating
current generator, a heavy product collecting base-cone section, a sensor for measuring the concentration of the heavy
product layer, a programmable controller, a heavy product discharging fluidized chamber and an underflow discharging
automatic control actuator. The method comprises the following steps: firstly, water is thrown into a sorting
machine in a pulsating way by the pulsating
current generator, to form an upward varying-accelerated pulsating-type ascending current; accordingly, low-density or fine-fraction materials can be subjected to upward accelerated movement under the action of the accelerated pulsating-type ascending current, thus achieving the overflow
discharge of the low-density or fine-fraction materials as the light or fine-fraction products; and high-density or coarse-fraction materials can be settled downwards in the
fluidized bed, thus achieving the
discharge of the high-density or coarse-fraction materials as the heavy or coarse-fraction products. Accordingly, the process for sorting materials by density on the basis of pulsating
fluidization or the process for grading materials by fraction on the basis of pulsating
fluidization can be achieved. The device and method of the invention have the advantages of simple operation, low
energy consumption, low sorting
lower limit, wide fraction range, high sorting accuracy and high reliability.