What is a design disadvantage of a pressurized fluidized bed furnace?

The design disadvantage of a pressurized fluidized bed furnace involves the potential for erosion, corrosion, and fouling of turbine blades when the system is operational. In this type of furnace, the fluidized bed is maintained at high pressure, which can lead to the mobilization of granular materials and fly ash. This can cause abrasive wear on components, particularly turbine blades that are downstream in the process.

While other options highlight advantages of a pressurized fluidized bed furnace, such as higher fuel efficiency, improved heat transfer, and reduced emissions, these do not represent design disadvantages. Instead, they illustrate the operational benefits that can be derived from using this technology. However, the issue of wear and damage to turbine blades presents a significant concern that must be managed with appropriate material selection, design modifications, and maintenance strategies.