US Patent 7409952 Portable breathing apparatus

A portable breathing apparatus has a respirator and a filter. The filter has a multifunctional strainer, a photocatalyst element, an exhauster, a high-pressure generator and an active carbon net in the interior thereof. Via the exhauster, external air can be filtered by the multifunctional strainer and mixed with ozone and negative ions generated from the photocatalyst element and the high-pressure generator thereby filtering and sterilizing the external air. Furthermore, the external air passes through a tube via the active carbon net to the respirator. Hence, it is easy for people wearing the portable breathing apparatus to breathe and experience the functions of air sterilization and filtration.