Abstract: A biological hazard mitigation apparatus permitting a material handling operation in the vicinity of a work area includes a plenum pneumatically coupled and proximate to one side of the work area, a filter sized to trap biological hazards and including an exhaust port, a blower including an inlet port and an exhaust port, and ducting pneumatically coupling the exhaust port of the filter to the inlet port of the blower, wherein the filter is disposed in the plenum, and adjacent surfaces of the filter and the plenum are substantially equal in surface area. If desired, the ducting includes first and second ducts, permitting a silencer to be disposed between the first and second ducts. Methods for operating the apparatus are also described.

Abstract: A biological hazard mitigation apparatus permitting a material handling operation in the vicinity of a work area includes a plenum pneumatically coupled and proximate to one side of the work area, a filter sized to trap biological hazards and including an exhaust port, a blower including an inlet port and an exhaust port, and ducting pneumatically coupling the exhaust port of the filter to the inlet port of the blower, wherein the filter is disposed in the plenum, and adjacent surfaces of the filter and the plenum are substantially equal in surface area. If desired, the ducting includes first and second ducts, permitting a silencer to be disposed between the first and second ducts. Methods for operating the apparatus are also described.

Abstract: A one-piece fan rotor optimized for construction and safety performance criteria is provided. The rotor has a hub with a radial cross-section defined by an I-beam. A plurality of unequally-spaced rotor blades are disposed circumferentially around and extend radially outward from the hub. Each rotor blade has a root portion coupled to the hub with the root portion defined by a concave fillet circumventing the rotor blade. For rotational balance, at least one of the forward side and backside of the hub incorporates an axially extending pad. Methods are provided for controlling stress on the rotor and for balancing the rotor.

Abstract: A one-piece fan rotor optimized for construction and safety performance criteria is provided. The rotor has a hub with a radial cross-section defined by an I-beam. A plurality of unequally-spaced rotor blades are disposed circumferentially around and extend radially outward from the hub. Each rotor blade has a root portion coupled to the hub with the root portion defined by a concave fillet circumventing the rotor blade. For rotational balance, at least one of the forward side and backside of the hub incorporates an axially extending pad. Methods are provided for controlling stress on the rotor and for balancing the rotor.