Patent ID: 8702849

Claim:
A dust screen for a topside inspection hatch of a dry bulk storage unit, for use during pneumatic transfer of frac sand from a transport vehicle via an active air stream inlet to said storage unit, comprising: a bag open at a first end and formed of a low density twill fabric having a rated air permeability between 15 and 35 CFM; said bag further having a net surface area in square feet exceeding the ratio of the pneumatic capacity of the transport vehicle in CFM to the rated air permeability of said dust screen in CFM; and an elastic band disposed within a sewn hem surrounding said open first end of said bag to attach said open end of said elongated bag around and in contact with a rim of said inspection hatch; wherein said dust screen, installed over said topside inspection hatch, is configured to inflate upward from said hatch to expose the full area of said dust screen to air exhausting from said hatch while retaining air-borne dust particles within said dust screen such that they settle into said storage unit, wherein no separate container is required to collect said dust particles.