An Advanced On-Load Boiler Cleaning Solution For Waste And Biomass Fired Boilers Based On Water As Cleaning Medium

摘要

The range of fuels fed to waste incineration plants extends from well-sorted domestic refusethrough mixed waste fractions to fuel mixtures that may additionally contain various types ofhazardous waste and biomass. This diversity results in a great number of fuel and ashcompositions. Among these are fuels with high as well as low calorific values and simple fuelashes just as highly problematic fuel ashes. The latter can lead to increased slagging in thefurnace and massive fouling in the convective passes of the boiler as well as acceleratedcorrosion. The plant operator is consequently faced with considerable challenges associated withunscheduled boiler downtime and production losses.The paper describes a fully automated, highly efficient and precise on-load boiler cleaning systemto control fouling in the superheater region of a boiler. The novelties of this system for cleaningthe convective pass of a boiler are the cleaning medium, which is water instead of the commonlyused steam, and the advanced positioning system of the spraying nozzle. The system allowstargeted, local cleaning of the convective heat exchanger surfaces of biomass boilers and wasteincinerators during operation.This paper points out challenges faced by plant operators and suppliers of boiler cleaningtechnology caused by the heterogeneous fuel composition, and describes in a well monitoredcase study how these challenges can be successfully met with process know-how and advancedcleaning technology.