• NTB Hitech Ceramics

Ferrules

NTB Ceratuff AL98 alumina ferrules protect tube inlets of the "shell and tube" type heat exchangers from hot gas corrosion and abrasive particle erosion, in the Claus process sulphur plants, since, the operating conditions inside the Claus unit can reach temperatures of 1600?-1650?C, especially during start-up and shut-down. The ferrules, with their excellent corrosive and mechanical wear resistant characteristics, provide protection to the refractory wall from erosion by the hot gases. In specially designed Ceratuff ferrules, the intermediate collar rests against the tube openings. This ensures that the refractory castable is anchored and reinforced by the extended part of the ferrule. Other ferrules are designed with collars embedded in the refractory wall at two different distances from the hot face. The laminating effect of the collar is reduced, when these ferrules are installed alternately. These fully sintered ferrules are not recommended for thermal shock applications. NTB also manufactures ferrules with 85% to 95% fused alumina and approximately 20 % porosity. These are specially recommended for applications with extreme thermal shocks. However, these show a higher corrosive and abrasive wear than NTB AL98 recrystallised alumina ferrules. The ferrules are available in standard sizes or customized designs.