DEVICE FOR PROTECTION OF INTERNAL SURFACE OF STEAM-BOILER DRUMS FROM THERMAL STRESSES Russian patent published in 2000 - IPC

FIELD: heat power engineering. SUBSTANCE: device has screen consisting of metal plates and bushes and distance plates positioned between screen, walls of drum and pipe connection. Peculiarity of construction is in bush with slits which allows its installation with preset free clearance relative to walls of drum and pipe connection. Number of slits may be from 4 to 6. They are positioned at an angle of at least 45 deg to longitudinal axis of drum. Screen thickness makes up to 2-4 mm. Screens are positioned at distance of 1-3 mm from protected surface of drum and pipe connection. Metal sheets of screen cover protected surface of drum walls at a distance of 1-1.5 diameters of hole. EFFECT: enhanced efficiency of protection. 6 dwg