PHOTO: Dome Technology
PELLETS¦
SMOOTH MOVE: Conveyors are key in moving wood pellets from receiving into storage at Enviva's Port of Chesapeake, Va., export operation.
on the size of the storage, that can save millions of dollars.” Since the bulk of the work is done inside of the domes, inclement weather doesn’t typically hinder construction plans, Roberts points out, and because of their waterproof membranes, there isn’t a risk of rain or moisture seeping through cracks, as there can be with concrete structures over time. Additionally, the 1.5-inch-thick layer of polyurethane foam keeps the temperatures balanced from inside and outside the domes, so no condensation is created on the inside.
A 50,000-ton dome can be constructed in about four to five months, plus a couple of more months to install a pellet reclamation system and aeration in the floors, if it’s part of the engineering plan. After that, it’s ready to be filled with pellets. Typically, a truck loaded with pellets will pull up to a platform and empty its cargo onto grates. The pellets fall through the grates onto a conveyor, which carries them to the top of the dome, where the process is monitored in a head house that rests on the surface. Inside the dome, a ladder softly delivers the pellets to the floor.
FEBRUARY 2013 | BIOMASS MAGAZINE 25