Raschig rings, or cylindrical packings, are considered part of the first generation of random packings. The first generation of random packing production dates from around 1895 to the late 1950s. These packings have a simple shape and a high production rate. Fluid moves more quickly through these packings, so they have lower pressure drop. They also have a lower specific surface area compared with other packings. The combination of these factors results in lower efficiency compared with other packings. Metal cylindrical packings have proven themselves as mass-transfer media in a wide range of applications. Metal Raschig rings have a long historical track record of improving efficiency in phase separations.
Since 1914, when Friedrich Raschig invented this type of tower packing, random tower packings have been extensively developed. Depending on tower operating conditions — such as operating temperature, humidity level, chemical corrosiveness, and so on — metal sheets of varying thicknesses and materials (carbon steel, stainless steel, etc.) can be used. Because of the low cost of Raschig rings, this product is widely used across industries such as oil, gas, petrochemicals, refineries, sulfuric acid plants, sugar, chemical industries, and others.
