Patent ID: 8518496
Filing Date: 2013-08-27
Classification: B23K,B32B,C22C,C23C,F22B,F23C,F23M,F28F

Abstract:
1. A method to slow the process of erosion and corrosion of a plurality of parallel tubes substantially vertically positioned in a tube wall at an interface with a refractory ledge of a refractory wall in a fluidized bed boiler, said method comprising: forming an erosion reducing recess in a fire side surface of at least one tube at a section of the at least one tube located proximate the refractory ledge; providing an erosion and corrosion resistant coating on a portion of the fire side surface of the at least one tube; extending the coating from the section proximate the refractory ledge laterally to each side of the at least one tube and longitudinally along the at least one tube to a distance of at least 12 inches from the refractory ledge and approximating an area where erosion or corrosion is expected to occur, the coating increasing a sidewall thickness of the at least one tube by at least 0.100 inches at the section proximate the refractory ledge; smoothly and gradually tapering a thickness of the coating in a direction away from the refractory ledge to nil over a distance of at least 12 inches from the refractory ledge; and maintaining at least a portion of the recess after the coating is applied thereto.