System and method of coating a proppant
View Patent ↗A system for adding dust control solution to a vertically falling first stream of a substantially dry particulate proppant, where the first stream has effective diameter, the system including a stationary, generally horizontal, deflector plate with drop-off edge, the plate mounted into the stream whereby the proppant collides with the plate and cascades from the plate around the drop-off edge to create a second stream of the particulate proppant having the general shape of the drop-off edge with a stream thickness and nozzles for spraying dust control solution into the second stream.
1. A system for loading a mass of essentially dry, free flowing dust free proppant particulate material into a transport vessel for immediate transportation to the hydraulic fracturing site for use in a fracturing operation, said system comprises a loading device receiving a supply of said particulate material having a D99 particle size of 50-2000 microns for discharging said particulate material by gravity in a vertical downwardly, unrestrained first stream of free falling particulate material, said first stream having an effective diameter and extending from an upper location downwardly in a gravity controlled given path, a fixed generally flat and generally horizontal deflector plate with a peripheral drop-off edge having a selected shape larger than said effective diameter, said plate mounted in a position to intersect said given path of particulate material so the falling particulate material in said first stream drops onto said deflector plate, forms a plate protecting dead bed of particular material on said plate and then cascades downwardly from around the peripheral drop-off edge creating a second free falling stream of particulate material having horizontal shape conforming to said selected shape of said peripheral drop-off edge and a width where said effective diameter of said first stream as at least 5 times said width of said second stream; a plurality of nozzles located below said deflector plate and generally facing said second stream; a pressurized supply of dust control solution to supply pressurized dust control solution to said nozzles for spraying into said second free falling stream of said particulate material; and, said transport vessel being located below and in line with said second stream to accumulate from said free falling second stream a mass of said proppant particulate material spray coated with said dust control solution while remaining free flowing.
2. A system as defined in claim 1 wherein said proppant is frac sand.
3. A system as defined in claim 1 wherein said coated particulate material has a moisture content of less than 0.3 percent so it remains free flowing.
4. A system as defined in claim 1 wherein said discharge device is a silo.
5. A system as defined in claim 1 wherein said discharge device is a transloader.
6. A system as defined in claim 5 wherein said transloader has an outlet structure and said drop-off edge of said deflector plate is not continuous and extends from a first point on said structure to a second point on said structure.
7. A system as defined in claim 1 wherein said drop-off edge is generally circular and said second free falling stream is generally in the shape of a cone.
8. A system as defined in claim 1 wherein said second stream width is less than 3 inches.