Closed system and method for shot peening adjacently located tubes in a power generation system

摘要

A shot peening system for peening the tubes of a steam generator continuously generates a shot stream and withdraws the shot stream dispensing nozzle into a vacuum chamber in an end effector while repositioning the nozzle for peening the next tube. A load tank forms an air lock for recycling shot recovered and cleaned by the vacuum system to a pressurized peen tank which feeds the recycled shot to a feed valve for mixing with a flow of compressed air to generate the shot stream. The pressure on the shot in the feed tank and the pressure of the compressed gas supplied to the feed valve are independently regulated to adjust the concentration of shot in the shot stream. The feed valve is constructed for ease of assembly and repair, and directs flow of a purge gas across the shot feed orifice and into a purge line which cycles shot and debris purged from the feed valve to the shot cleaning equipment on the vacuum side.