Apparatus for separating material from a pneumatic conveyor

Claim 1

Apparatus for separating material from a pneumatic conveyor comprising, in combination: A. duct means, at least one portion thereof having a rectilinear axis, said duct means having a passageway therethrough for conveying material on a stream of gas; and B. separator means, interposed in said duct means at said rectilinear portion, for removing conveyed material from said duct means, said separator means comprising, in combination: a. a gas-permeable endless belt having two parallel rectilinear sections of travel arranged to traverse said passageway at an angle of approximately 45* at said rectilinear portion of said duct means, such that material conveyed in said duct means will impinge on one of said rectilinear sections; b. drive means for continuously moving said rectilinear sections of said endless belt in opposite directions across said passageway at a speed such that the total speed as well as the component speed of said conveyed material in the direction of said rectilinear axis of said duct means remain substantially constant when said material impinges on said one rectilinear section; c. two rotatable roller means of the same diameter, each arranged on opposite sides of said passageway of said duct means, for holding said endless belt in positIon across said passageway, at least one of said roller means being coupled to, for rotation by, said drive means; d. means providing quick-removal of said endless belt comprising, in combination: i. brace means arranged at both ends of said two roller means for holding said two roller means in spaced apart relation; ii. rail means connected to said duct means adjacent and parallel to each of said brace means for slidably holding said brace means; iii. means for locking said brace means in a particular position along said rail means; iv. closure means connected to said duct means at one end of said brace means for providing a closable opening for said endless belt, said roller means and said brace means wherein said closure means includes first handle means to facilitate manual opening; and v. second handle means, connected to said brace means, to facilitate manual movement of said brace means along said rail means so that said endless belt, said roller means and said brace means may be inserted in and removed from said duct means as a unit; e. seal means, arranged at one end of said one rectilinear section of said endless belt, for preventing the flow of gas past said end into or out of said duct means while permitting the removal of material from said duct means by said one rectilinear section, said seal means comprising, in combination: i. a first roller, connected to said drive means and arranged to rotate against one side of said one rectilinear section at said one end with a surface speed equal to that of said endless belt, said first roller having a surface made of soft resilient material to prevent the flow of gas between said first roller and said one rectilinear section while permitting the removal of material therebetween; and ii. a second roller arranged to roll against the other side of said one rectilinear section of said endless belt at the point opposite said first roller; f. wiper means, arranged to contact said surface of said first roller, for scraping material off of said first roller after it has been removed from said passageway; and g. suction means for removing particles of material which penetrate said one rectilinear section and do not pass through the other rectilinear section of said endless belt comprising, in combination: i. a suction housing arranged between said two rectilinear sections and adjacent to said other rectilinear section of said endless belt; and ii. means for establishing a lower pressure in said suction housing relative to the pressure immediately outside of said suction housing, including at least one bypass tube connecting said suction housing with the region of said passageway which is downstream of said endless belt; whereby the material conveyed on said stream of gas through said passageway in said duct means impinges on said one side of said one rectilinear section of said endless belt and is conveyed out of said passageway while said stream of gas passes through both of said rectilinear sections of said endless belt and remains in said passageway.