An air breathing device, comprising:
- a casing;
- an air passage cavity encompassed by the casing;
- an air intake port or a plurality of air intake ports, the air intake port or each of the plurality of air intake ports connecting the air passage cavity to an outside of the casing through a corresponding air intake damper comprising a plurality of air intake damper blades and a plurality of air intake damper hinges, each of the plurality of air intake damper blades configured to rotate in a first direction around a corresponding hinge of the plurality of air intake damper hinges in response to an air pressure inside of the air passage cavity being less than an air pressure outside of the casing to open the air intake damper, and each of the plurality of air intake damper blades configured to rotate in a second direction around the corresponding hinge of the plurality of air intake damper hinges in response to an air pressure inside of the air passage cavity being more than an air pressure outside of the casing to close the air intake damper;
- an air discharge port or a plurality of air discharge ports, the air discharge port or each of the plurality of air discharge ports connecting the air passage cavity to the outside of the casing through a corresponding air discharge damper comprising a plurality of air discharge blades and a plurality of air discharge hinges, each of the plurality of air discharge damper blade configured to rotate in a third direction around a corresponding hinge of the plurality of air discharge damper hinges in response to an air pressure inside of the air passage cavity being more than an air pressure outside of the casing to open the air discharge damper, and each of the plurality of air discharge damper blade configured to rotate in a fourth direction around the corresponding hinge of the plurality of air discharge damper hinges in response to an air pressure inside of the air passage cavity being less than an air pressure outside of the casing to close the air discharge damper;
- an air tube configured to connect the air passage cavity to a mouth of a person wearing the air breathing device;
- an ultraviolet (UV) light source or a plurality of UV light sources inside the air passage cavity;
- a first UV light screen or a first plurality of UV light screens located inside the air tube, the first UV light screen or the first plurality of UV light screens configured to separate the air passage cavity from the mouth of the person;
- and
- a second UV light screen separating the air passage cavity from the air intake port and the air discharge port or a second plurality of UV light screens, each of the second plurality of UV light screens separating the air passage cavity from one of the plurality of air intake ports and one of the plurality of air discharge ports.