Wear is defined as damaging gradual removal or deformation of material at solid surfaces. On a chemical basis, wear is called corrosion. In mechanical terms, wear is erosion, or more specifically abrasion.
Abrasion In Refractory
Abrasion is defined as the loss of material that occurs when hard particles, also called abrasives, are forced against and move along a solid surface. The notion that abrasion is a loss is important to remember here, as it will also define the testing for abrasion resistance.
Early in its history, Resco was confronted with abrasion challenges while it was serving the petroleum refining industry just after World War 2. It was at this time that technology for the Fluid Catalytic Cracking Unit abbreviated the FCCU, and was being perfected.
The FCCU is a pair of furnaces that are pressure vessels. One vessel is called the reactor in which gasoline is made by cracking crude oil. A fine, but abrasive, alumina catalyst is used for the cracking reaction.
The second vessel is the regenerator in which carbon that is deposited on the catalyst is burned off, regenerating the catalyst. Inside the vessels are refractory-lined cyclones that remove the catalyst from the gas stream. Between the two vessels are transfer lines that convey the catalyst. The vessels operate at about 1500°F, so the transfer lines have to be refractory lined. The refractory must be abrasion resistant to survive the 5 to 8-year campaign between FCCU repairs.
Resco’s most famous product is RESCOBOND AA-22S, which is the abrasion-resistant hard refractory castable that protects the transfer lines. The photo shows an installation of AA-22S in a transfer line. AA-22S is commonly placed into the hex-steel mesh for both the transfer lines and the vessel cyclone linings, and it is known the world over.