A study on the particle temperature in a conical fluidized bed using infrared thermography

Abstract

Of the three main modes of heat transfer in fluidized bed reactors, surface-to-bed heat transfer has been more thoroughly studied compared to gas-to-particle or solid-to-solid heat transfer. The difficulty in studying both gas-to-solid and solid-to-solid heat transfer processes is due to a limited ability to measure the temperature of the particles. The traditional method to measure temperature, such as inserting temperature probes into the bed, do not provide accurate results because these measure the temperature of the bed and not the solid particles. The present study introduces a technique using infrared thermography to measure the particle temperature. The particle temperature was measured using an IR camera, and a type-K thermocouple was used to measure the bed temperature. Glass beads with different sizes were used as bed material fluidized by air to study the effect that the inlet gas velocity and particle size had on the particle temperature. An increase in the inlet gas velocity resulted in a decrease in the particle temperature without a noticeable effect on the bed temperature, and an increase in the particle size resulted in an increase in the temperature of both the particles and the bed.