![]() ![]() Such chemically treated carbon is known as "activated carbon." The type of activated carbon employed in a given filter cartridge depends on the specific type of industrial contaminant to be screened. The adsorptive properties of carbon can be enhanced by impregnating the particles with specific reactants or decomposition catalysts. However, inorganic vapors are not usually strongly adsorbed on carbon. Carbon based filtrants are commonly used because they can adsorb large quantities of organic gases, especially high molecular weight vapors like those used in chemical warfare. The filter cartridge is a plastic canister 3-4 inches (8-10 cm) across and 1 inch (2.5 cm) deep, which contains a filtration aid. Raw MaterialsĪ full-face gas mask consists of a filter cartridge, flexible face covering piece, transparent eye lenses, and a series of straps and bands to hold the device snugly in place. This article will focus on manufacture of the full face type of mask used for industrial applications. They may be designed for military as well as industrial use but, even though the two types are similar in design, the military masks must meet different standards than those used in industry. ![]() These masks are produced in several styles, some that cover only the mouth and nose and others that cover the entire face, including the eyes. Today APRs are used to filter many undesirable airborne substances, including toxic industrial fumes, vaporized paint, particulate pollution, and some gases used in chemical warfare. In addition, masks have been made more comfortable and tighter fitting with modern plastics and silicone rubber compounds. ![]() Since that early time, there have been significant advances in gas mask technology, particularly in the area of new filtration aids. Morgan's device later evolved into the gas mask, used in World War I to protect soldiers against chemicals used in warfare. When the Cleveland Waterworks exploded in 1916, Morgan showed the value of his invention by entering the gas-filled tunnel under Lake Erie to rescue workers. The first APR was patented in 1914 by Garret Morgan of Cleveland, Ohio, an African American inventor also credited with major improvements in the traffic signal. The latter type, known as an Air Purifying Respirator (APR), consists of a tight-fitting face piece that contains one or more filter cartridges, an exhalation valve, and transparent eye pieces. Masks may be designed to carry their own internal supply of fresh air, or they may be outfitted with a filter to screen out harmful contaminants. A gas mask is a device designed to protect the wearer from noxious vapors, dust, and other pollutants. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |