Patent ID: 7481605
Filing Date: 2009-01-27
Classification: B05B,B65G

Abstract:
1. A system for delivering and spraying powder coating materials, comprising: a powder reservoir; a feed line connected to said reservoir; a conveyance device for the pneumatic conveyance of powdered material connected to said feed line; a delivery line connected to said conveyance device; wherein said conveyance device includes: a first conveying chamber and a second conveying chamber, said first conveying chamber comprising a first rigid gas permeable filter element encircled by a first annular housing, said second conveying chamber comprising a second gas permeable rigid filter element encircled by a second annular housing; a first inlet pinch valve at said inlet of said first conveying chamber; a first outlet pinch valve at said outlet of said first conveying chamber; a second inlet pinch valve at said inlet of said second conveying chamber; a second outlet pinch valve at said outlet of said second conveying chamber; a first Y-shaped line section having one inlet and two outlets, with said inlet connected to said reservoir through said feed line and said outlets connected to said first inlet pinch valve and said second inlet pinch valve respectively; a second Y-shaped line section having two inlets and one outlet, with said inlets being connected to said first outlet pinch valve and said second outlet pinch valve respectively, and said outlet connected to said delivery line; one or more control valves being operable in a first mode of operation to selectively open or close said first and second inlet pinch valves and said first and second outlet pinch valves, and to selectively apply negative pressure or admit compressed gas through said first and second rigid gas permeable filter elements to draw in powdered material from said reservoir through said feed line into said first conveying chamber while said second conveying chamber forces powdered material, which had been previously drawn into said second conveying chamber, out of said second conveying chamber through said delivery line; and to draw powdered material from said reservoir through said feed line into said second conveying chamber, while said first conveying chamber forces powdered material, which had been previously drawn into said first conveying chamber, out of said first conveying chamber through said delivery line; said one or more control valves being operable in a second mode of operation to clean powdered material from said first and second conveying chambers, said first and second inlet pinch valves, said first and second outlet pinch valves, said first and second Y-shaped line sections, said feed line, and said delivery line by operating said one or more control valves to selectively open said first and second inlet pinch valves and first and second outlet pinch valves while selectively admitting compressed gas through said first and second rigid gas permeable filter elements to allow compressed gas to flow through said first and second conveying chambers, said first and second inlet pinch valves, said first and second outlet pinch valves, said first and second Y-shaped line sections, said feed line, and said delivery line.