Industrial vacuum loading apparatus

In a vacuum operated industrial loading apparatus of the type including a vacuum conduit system having an open inlet and exhaust fan means for creating a flow of air through the system from the open inlet, an enlarged separation chamber having an inlet and an air outlet connected in the conduit system and a material discharge outlet in the bottom wall thereof and spaced from the air outlet, a first filter screen mounted over the air outlet for filtering a solid material from air flowing through the separation chamber and a paddle wheel assembly mounted for rotation about a fixed axis within the separation chamber and including a plurality of radially extending arms cooperating with the walls of the separation chamber to define a plurality of individual conveyor chambers each movable successively past the filter screen to remove solid materials collected thereon and the discharge outlet to discharge the removed materials while maintaining at least a partial air lock between the material discharge outlet and the air outlet, the improvement comprising secondary air lock means including an elongated conduit having one end positioned over and communicating with said discharge outlet, said conduit extending downwardly from said bottom wall and terminating in an open bottom end, an elongated screw conveyor mounted within said conduit, said screw conveyor having a low pitch and normally acting to retard the flow of solid materials deposited into the upper end of said conduit and onto said conveyor through said discharge outlet by said paddle wheel assembly, and drive means for rotating said screw conveyor to convey the solid materials downwardly through said conduit to be discharged through said open bottom end whereby solid materials deposited onto said screw conveyor collect thereon and cooperate therewith to form said secondary air lock between said air outlet and the open end of said conduit, and wherein said separation chamber comprises a substantially cylindrical upright housing having a substantially cylindrical side wall and top and bottom end walls and having an opening in said side walls defining said air outlet, said filter screen being mounted over said air outlet in said side wall, said inlet being formed in said top wall and said discharge outlet being formed in said bottom wall at a point circumferentially spaced from said inlet and from said air outlet.