US Patent 9790022 Container to deliver bulk granular material

A container is constructed to carry granular material from a quarry or source to the frac site. An open frame the size of a standard cargo container is constructed. An enclosed hopper is formed using flat sheet metal with bolted together perpendicular edges. The hopper is set within, and attached to, the frame. Top hatches provide for loading the hopper, and a lower sliding gate in a bottom opening provides for unloading the hopper. The bottom of the hopper is at an angle slightly above the angle of repose of the granular material carried therein.