Conveying system for particulate materials

Claim 1

A PNEUMATIC HOPPER ASSEMBLY FOR PARTICULATE MATERIALS COMPRISING: A PRESSURE-TIGHT HOPPER; CONTROLLABLE INLET MEANS INTO THE TOP PORTION OF SAID HOPPER FOR MATERIAL TO BE CONVEYED; SAID HOPPER HAVING A GENERALLY FRUSTOCONICAL, DOWNWARDLY CONVERGENT BOTTOM WALL AND AN OUTLET AT THE BASE THEREOF; CONVEYING CONDUIT MEANS CONNECTED TO SAID OUTLET; AN ANNULAR PRESSURE MANIFOLD AROUND SAID FRUSTO-CONICAL BOTTOM WALL ADJACENT THE BASE THEREOF; PRESSURIZED FLUID INLET MEANS INTO SAID ANNULAR CHAMBER, TANGENTIALLY THERETO, COMMUNICATING ANNULAR OUTLET SLIT IN SAID BOTTOM WALL, COMMUNICATING WITH SAID MANIFOLD, AND DIRECTED UPWARDLY INTO SAID HOPPER ALONG SAID FRUSTOCONICAL WALL, CAUSING THE PRESSURIZED GASES INTRODUCED TANGENTIALLY INTO SAID ANNULAR MANIFOLD TO SWIRL OUT OF SAID SLIT IN A CONTINUOUS SPIRALING LAMINAR FILM ALONG SAID HOPPER WALL TO SUSPEND THE PARTICULATE MATERIALS THEREAGAINST; AND MEANS TO FORM A PRESSURE DIFFERENTIAL BETWEEN SAID CONVEYING CONDUIT MEANS AND THE TOP OF SAID HOPPER TO FORCE THE SUSPENDED MATERIALS THROUGH SAID OUTLET.