A dedusting apparatus for cleaning dirt and debris from particulate material, comprising: a housing having laterally spaced side walls, longitudinally spaced front and rear walls and vertically spaced top and bottom walls, said housing being divided into a front chamber and a rear chamber with a generally vertical transverse central wall therebetween extending between said side walls and between said top and bottom walls, said central wall being formed with a main opening therein, said rear chamber being divided into an upper area and a lower area, said upper area including a first generally horizontal floor extending between said central wall and said rear wall and separating said upper and lower areas (19a, 18a), a product infeed located at an upper portion of said front chamber for the introduction of particulate material to be cleaned into said front chamber; a product outlet opening located in a lower portion of said front chamber for the discharge of particulate material from said housing; an air inlet in said lower area of said rear chamber and being in flow communication with said main opening to direct a flow of air into said front chamber; an air outlet in said upper area of said rear chamber and being in flow communication with said front chamber via exit openings located at an upper portion of said front chamber; and a primary wash deck apparatus mounted between said front wall and said central wall to be in flow communication with said main opening so that air from said air inlet will flow upwardly through said wash deck apparatus to separate said dirt and debris from said particulate material received on said wash deck apparatus from said product infeed, said primary wash deck apparatus being detachably mounted to said central wall. a housing having laterally spaced side walls, longitudinally spaced front and rear walls and vertically spaced top and bottom walls, said housing being divided into a front chamber and a rear chamber with a generally vertical transverse central wall therebetween extending between said side walls and between said top and bottom walls, said central wall being formed with a main opening therein, said rear chamber being divided into an upper area and a lower area, said upper area including a first generally horizontal floor extending between said central wall and said rear wall and separating said upper and lower areas (19a, 18a), a product infeed located at an upper portion of said front chamber for the introduction of particulate material to be cleaned into said front chamber; a product outlet opening located in a lower portion of said front chamber for the discharge of particulate material from said housing; an air inlet in said lower area of said rear chamber and being in flow communication with said main opening to direct a flow of air into said front chamber; an air outlet in said upper area of said rear chamber and being in flow communication with said front chamber via exit openings located at an upper portion of said front chamber; and a primary wash deck apparatus mounted between said front wall and said central wall to be in flow communication with said main opening so that air from said air inlet will flow upwardly through said wash deck apparatus to separate said dirt and debris from said particulate material received on said wash deck apparatus from said product infeed, said primary wash deck apparatus being detachably mounted to said central wall.