What size of coal can typically be burned in a fluidized bed boiler?

In a fluidized bed boiler, the typical size of coal utilized ranges from approximately 1.6 mm to 6 mm. This size range is crucial for effective combustion and to ensure the coal can be fluidized properly within the bed. The coal particles need to be small enough to allow for good mixing and contact with the air, which enhances combustion efficiency and ensures uniform heat distribution throughout the bed.

Using particles that are too small may lead to excessive losses of coal in the flue gas, while particles that are too large may not fluidize properly, leading to poor combustion and heat transfer. Therefore, the size range of 1.6 mm to 6 mm is optimal for balancing effective combustion, minimizing emissions, and maintaining operational efficiency in fluidized bed systems. This understanding is vital for anyone preparing for exams or working with this type of boiler technology.