Grouping of air nozzles in a fluidized bed boiler, grid for a fluidized bed boiler and fluidized bed boiler

摘要

An air nozzle arrangement for a fluidized bed boiler, comprising an air feed pipe and an air nozzle which limit an air feed duct configured to supply air to the furnace of the fluidized bed boiler. The air nozzle arrangement comprises a surface configured to guide coarse material along said surface. At least part of said surface is thermally insulated from the air nozzle and/or the air feed pipe. Furthermore, at least part of said surface is configured to protect at least part of said air nozzle and/or air feed pipe. Thus, the temperature of said surface is configured to be high when the fluidized bed boiler is in operation, whereby the solidification of molten material of the fluidized bed in the air nozzle arrangement is reduced.