Factors Affecting Clans Waste Heat Boiler Design and Operation

摘要

The Claus Waste Heat Boiler(WHB)is a critical piece of equipment in a Sulphur Recovery Unit(SRU);its fundamental purpose is as a heat transfer device used in energy recovery.Sulphur plant operators have recently been experiencing higher than normal WHB failure rates,perhaps from oxygen enrichment and pushing rates.The WHB has become the weak link in the SRU;consequently,increased attention is now being given to its design and operation.New performance standards are being considered to limit the mass flux of future designs;however,this may be an unwarranted oversimplification.In this work,we demonstrate that although mass flux is certainly a parameter for design consideration,there are a host of additional factors particularly on the water side also having vital consequence.In some cases,limiting mass flux may lead to other unintended complications.Unless the boiler is treated as a heat transfer device with simultaneous chemical reactions and radiation,these complications may go unnoticed.Several important parameters beyond mass flux are evaluated and shown to have notable effects on WHB economics,reliability,safety,and on overall Claus unit performance.