Family and Neighborhood Risks: How They Relate to Involvement in Out-of-School Time Activities. Research-to-Results Fact Sheet. Publication #2008-06.

Abstract

A device which permits the conveyance of a dry fluid substance from one receptacle to another without the release of a significant amount of dust into the surrounding atmosphere is provided. The device is a housing with an interior volume divided into two sections and having an access opening and a discharge opening. A dry fluid substance is introduced into the device and into an inner chamber within the interior volume of the device which guides the substance from the access opening to the discharge opening and causes the separation of particulate matter from the substance. The particulate matter dispersed from the substance is drawn by a vacuum applied to the housing from the inner chamber into the filter chamber where the particulate matter is retained on a plurality of fine filter bag assemblies. At predetermined intervals, the vacuum applied to the device is shut off which causes the retained particulate matter to fall from the filter bags downwardly in the filter chamber through a pathway and discharged into the center of the stream of substance being discharged through the discharge opening. Thus, the particulate matter is reintroduced into the stream of substance at the point of discharge, but is delivered within the stream of substance which limits the creation of dust at the discharge point. In a preferred embodiment, the clean air chamber and filter chamber of the device are divided into quadrants and each quadrant is connected by a hose to the source of the vacuum. A valve positioned between the hose and the source of the vacuum permits the sequential closure of one section of the device while leaving the remaining sections open. This permits the particulate matter to be released from an individual section or sections of the device during the loading process. This can be regulated by conventional devices.