Why can the fire protection gas mask be anti-virus?

Fire-fighting gas mask is a special personal protective equipment for personal protection, and it is also a personal protective equipment for soldiers. It is worn on the head to protect people's respiratory organs and face, and prevent bacteria, dust, toxic and harmful gases, toxic gases, steam and other toxic substances from harming people. . Fire gas masks are widely used in petroleum, chemical, machinery manufacturing and other fields, and can also play an important role in protecting the personal respiratory system from severe smog and photochemical smog in the city. Fire protection gas mask can be divided into full face mask and half face mask, full face mask can be divided into positive pressure type and negative pressure type. Why do you say that the fire protection gas mask can protect against viruses?
First of all, the fire protection gas mask is divided into two parts: the mask and the tank. Through these two aspects, the anti-virus mask can be more effective anti-virus.
Secondly, the fire protection gas mask adopts the principle of air pump to form a sealed environment. There is a nasal mask in the mask, and an inhalation valve is installed in the mask to control the entry of gas. There is an exhalation valve under the mask. The exhaled air can be discharged from the exhalation valve, but the entire gas mask cannot enter the mask when in use. Outside air enters the mask through the gas filter, and then enters the inlet nasal mask through the inhalation valve for human breathing. The exhaled air is discharged from the mask through the exhaust valve. In this way, the gas mask of the gas filter tank plays a role of anti-virus.
Finally, the internal structure of the filter consists of melt blown cloth layer, activated carbon layer, chemical agent layer and melt blown cloth layer from top to bottom. The blown dust layer can play the role of the dust layer and the dust layer. The activated carbon layer is the main body of the filtering effect. The adsorbed activated carbon can adsorb toxic gases, and then differentiate and purify it through the chemical reagent layer. This is the anti-virus principle of the poison filter tank. The filter adopts 1.5mm coal columnar activated carbon, which is not easy to be broken, and the pore structure is developed to maximize the absorption of toxic gases.