A classifier cleaning and optimization device is provided. The device includes a chamber that is adapted to contain a fluidized bed, an array of two or more adjacently arranged inclined plates positioned above the fluidized bed wherein an inclined channel is formed between each pair of adjacent inclined plates, and a means for introducing a process liquid into the chamber between the fluidized bed and the array of inclined plates such that in use, the process fluid travels through at least one of the inclined channels. A method of cleaning the separation section of a classifier is also disclosed herein.