Method and apparatus for elutriation of shot from mineral fiber

Abstract

An elutriation apparatus for de-shotting fibrous material carried in a liquid current comprises a battery of washing vessels located in sequence. A power driven mixing apparatus is provided in the first washing vessel of the sequence for dispersing the fibrous material. The upper section of each washing vessel is divided into two compartments by a baffle, while the vessel's lower section is unobstructed, whereby a current of liquid carrying fibrous material which is introduced into the upper section of the vessel to one side of the baffle travels downwardly and then underneath the baffle and upwardly to the vessel's upper section to the other side of the baffle. The latter upper section is provided with a spout for discharge of the fibrous dispersion from the vessel to the next washing vessel or to the separator apparatus located after the last washing vessel of the sequence for removal of the wash liquid from the de-shotted fibrous material. The bottom of each washing vessel is provided with a discharge apparatus for removal of the shot which settles during the cleaning operation. The elutriation method comprises the steps of (a) continuously flowing the liquid through the vessels, (b) delivering shot-containing fibrous material to the first washing vessel, (c) gently mixing this shot-containing material in the first washing vessel to convert the material into a dispersion of fibrous material and shot, (d) discharging from the washing vessels the shot which settles as the flowing liquid and associated dispersed materials pass through the vessels, and (e) separating the flowing liquid from the de-shotted fibrous material after passage of the flowing liquid and associated de-shotted fibrous material through the washing vessels.