A preflushing unit (10) preflushes a breathing gas circuit (210) of a closed-circuit respirator (200). A basic body (20) has an inlet port (22), feeding breathing gas from a breathing gas supply (220), an outlet port (24) discharging breathing gas into the breathing circuit, and a flow section (32) fluid connecting a valve chamber (30). A valve body (40) with a sealing surface (42) is arranged in the valve chamber (30). An elastomer body (50) with a counter-sealing surface (52) in the valve chamber, fluid tight separates the flow section from a control section (34). The counter-sealing surface acts with a sealing force against the valve body for sealing the flow section. A control port (26) of the basic body provides a controlled feed of breathing gas from the breathing gas supply into the control section for pressure equalization between the flow section and the control section.

A wearable air sterilizer features an air disinfection chamber and a slidable face shield mounted on a headwear item such as a conventional baseball cap. The air disinfection chamber features one or more LEDs emanating ultraviolet light at a germicidal wavelength to inactivate airborne pathogens in the passing air and provide the user with a personalized air supply free from COVID-19 and other viruses.

A wearable air sterilizer features an air disinfection chamber and a slidable face shield mounted on a headwear item such as a conventional baseball cap. The air disinfection chamber features one or more LEDs emanating ultraviolet light at a germicidal wavelength to inactivate airborne pathogens in the passing air and provide the user with a personalized air supply free from COVID-19 and other viruses.

The present disclosure relates generally to respirators where inhaled air and exhaled air are separated into different channels to permit a user to always inhale fresh air. The respirators described herein can filter inhaled air, and optionally exhaled air.

The present disclosure relates generally to respirators where inhaled air and exhaled air are separated into different channels to permit a user to always inhale fresh air. The respirators described herein can filter inhaled air, and optionally exhaled air.

A face mask uses a neck hanger to facilitate the flow of filtered fresh air inside the face mask for inhaling. The neck hanger is a lightweight tube that has a U shape and hangs from the neck of a user. The neck hanger houses a fan with a filter at either side, and a battery with a controller circuit. Two flexible pipes connect the face mask to the neck hanger from either side. The neck hanger sucks the air from the environment using a fan and filters it before being blown into the face mask through a flexible pipe. The face mask's contaminated interior air through another flexible pipe is sucked be another fan and filtered by a filter before being released into the environment.

There is provided a method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user, the system comprising a fan powered by a battery in communication with a variable speed electric motor, the variable speed electric motor is controlled by an electronic control unit for delivering a forced flow of air through at least one filter to a user, comprising the steps of: (a) determining an estimated system run time by summing a battery run time remaining and a system run time; and (b) altering a speed of the variable speed electric motor when the estimated system run time is equal to or less than a desired system run time.

There is provided a method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user, the system comprising a fan powered by a battery in communication with a variable speed electric motor, the variable speed electric motor is controlled by an electronic control unit for delivering a forced flow of air through at least one filter to a user, comprising the steps of: (a) determining an estimated system run time by summing a battery run time remaining and a system run time; and (b) altering a speed of the variable speed electric motor when the estimated system run time is equal to or less than a desired system run time.

A process and apparatus to preclude unfiltered atmospheric gases and the products of human respiration including carbon-dioxide (CO.sub.2) with carbon-14 (.sub.14C) from contaminating greenhouse atmospheric gases which has utility in growing agricultural products with a reduced abundance of .sub.14C are disclosed. Agricultural products with reduced .sub.14C content can be grown in greenhouses with filtered atmospheric gases for the benefit of reducing harmful damage to human DNA. Agricultural production in greenhouses still requires humans to plant, maintain, and harvest crops in many cases. The process and apparatus allow for humans to access, work, and operate in these controlled environments without contaminating the atmospheric gases and agricultural products therein with respiration products and unfiltered atmospheric gases containing radioactive .sub.14C.

A process and apparatus to preclude unfiltered atmospheric gases and the products of human respiration including carbon-dioxide (CO.sub.2) with carbon-14 (.sub.14C) from contaminating greenhouse atmospheric gases which has utility in growing agricultural products with a reduced abundance of .sub.14C are disclosed. Agricultural products with reduced .sub.14C content can be grown in greenhouses with filtered atmospheric gases for the benefit of reducing harmful damage to human DNA. Agricultural production in greenhouses still requires humans to plant, maintain, and harvest crops in many cases. The process and apparatus allow for humans to access, work, and operate in these controlled environments without contaminating the atmospheric gases and agricultural products therein with respiration products and unfiltered atmospheric gases containing radioactive .sub.14C.