Portable, low-power air filtration system
An air filtration system is described that is suited for CBRN and ColPro applications, and has an integrated inertial particle separator (IPS) and scavenge fan blower as a pre-dust/particle filter, a variable speed fan blower, and a filter housing that mounts two gas-particulate filter sets. The variable speed fan blower, managed by a motor control unit and motor speed algorithm, automatically adjusts its speed to maintain constant air flow regardless of its altitude.
1. A fan blower for providing chemically and/or biologically filtered air, comprising:
a blower enclosure having an air inlet, an air outlet, and an internal cavity; and,
a fan assembly positioned within said internal cavity to move air from said air inlet out through said air outlet; said fan assembly comprising a mixed flow fan and a permanent magnet motor coupled to and driving rotation of said mixed flow fan;
an atmospheric pressure sensor in communication with ambient air outside said fan blower;
a static air pressure sensor in communication with said internal cavity;
a first chemical and biological agent sensor;
a microprocessor configured to adjust a speed of said fan assembly based on sensor readings of said atmospheric pressure sensor and sensor readings of said static air pressure sensor; and said microprocessor being configured to trigger an alarm based on data from said first chemical and biological agent sensor;
an inertial particle separator disposed adjacent to, and upstream of said mixed flow fan; and,
a scavenge fan connected to said inertial particle separator that removes separated, particle-containing air from said inertial particle separator; said scavenge fan further comprising an exhaust tube having an outer, open end positioned outside of said fan blower, so as to expel said particle-containing air from said fan blower.
2. The fan blower of claim 1 , wherein said mixed flow fan comprises a first fan connected to a second fan via a common axle, and a plurality of stationary vanes located on a stationary member and being disposed between said first fan and said second fan.
3. The fan blower of claim 2 , wherein said permanent magnet motor further comprises a motor stator connected to said stationary member, and a permanent magnet rotor fixed to said common axle and disposed radially inwards of said motor stator.
4. The fan blower of claim 2 , wherein said first fan and said second fan have a diameter of about 6 inches.
5. The fan blower of claim 1 , wherein said first chemical and biological agent sensor is positioned adjacent to said air outlet of said blower enclosure.
6. The fan blower of claim 5 , further comprising a second chemical and biological agent sensor positioned adjacent to said air inlet of said blower enclosure and said microprocessor being configured to compare sensor readings of said first chemical and biological agent sensor and said second chemical and biological detection sensor.