Abstract: A blending apparatus, inexpensive in construction and requiring a minimum of recirculation, is today essential for economical and thorough blending of particulate material, for example, plastic pellets of virgin material and of pellets that have been reconstituted from recycled material. Construction of the blender is low in cost because the customary receiver, and its piping, conventionally installed below the blender are eliminated. The novel convex baffle serves:(1) as a termination surface for the conventional perforated blending conduits; and (2) retains a toroidal annular volume of particulate material in position between the upper outer surface of the baffle and the inside wall of the blender. The particulate material passes through the blending tubes, drops into the blending area below the convex baffle, whereupon the small amount of particulate material in the toroidal block or "keystone joist" is released to proportionally blend with it.

Abstract: A blending apparatus, inexpensive in construction and requiring a minimum of recirculation, is today essential for economical and thorough blending of particulate material, for example, plastic pellets of virgin material and of pellets that have been reconstituted from recycled material. Construction of the blender is low in cost because the customary receiver, and its piping, conventionally installed below the blender are eliminated. The novel convex baffle serves: (1) as a termination surface for the otherwise conventional perforated blending conduits; and (2) retains a toroidal annular volume of a specific particulate material as determined by an analogous test apparatus in position between the upper outer surface of the baffle and the inside wall of the blender.

Abstract: A gravity blending apparatus and methods of gravity blending involving an improved venting arrangement, by means of which an increase in the "thru-put" flow rate of a gravity blender apparatus is provided by venting the underside of an inverted cone within a collecting chamber to one or more low pressure zones. Advantageously, such venting may proceed progressively from the underside of an inverted cone within the collecting chamber to a low pressure zone within the upper portion of the collecting chamber, with venting continuing by way of auxiliary or further venting conduit means to the underside of a material distributing, inverted cone in the lower portion of the base of the main bin of the gravity blender.

Abstract: Apparatus for blending free-flowing particulate material. The blender includes a hopper having a central blending tube disposed therein. The blending tube has axially and circumferentially spaced apart openings sized to pass the particulate material into the interior of the blending tube. Disposed within the blending tube are a plurality of baffles which create imperforate, annular areas above the openings. Also disposed within the hopper are a series of circumferentially cascading weir plates which divide the hopper into a plurality of compartments. Each of the compartments communicates with at least one of the openings in the blending tube. In a preferred embodiment the baffles are spaced apart unevenly along the axis of the blending tube so that the openings to the interior of the tube at a particular level service substantially equal volumes of the particulate material in the hopper. In this embodiment the topmost baffle has a lower open area substantially equal to the imperforate annular areas.

Abstract: A method of reducing the formation of fines and streamers in connection with the gas conveying of plastic particles (and the resulting conveying apparatus), characterized by the maintenance of particular acute angle relationships between the longitudinal flow direction of particles and the impact direction of shot-peening previously used to condition pipe section interior wall means.

Abstract: Disclosed is an apparatus for separating a pellet-like product from fines (e.g., dust) mixed therewith. The apparatus includes a vertically disposed housing having an upper fines outlet and a lower product outlet. An inlet conduit passes through the housing intermediate the fines outlet and the product outlet and terminates in an upwardly facing inlet nozzle. The inlet conduit receives quantities of product and fines along with a propellant fluid (e.g., pressurized air). An impact baffle is supported within the housing having a concave impact surface that faces the inlet nozzle and that is positioned to intercept the product pellets issuing from the inlet nozzle. The impact baffle is sized and supported to provide an annular flow oriface for the propellant fluid (and fines mixed therewith) between the impact baffle and the housing.