Distribution of Particles from Inlet Pipe in Fluidized Beds with Different Inlet Structures

For actual industrial process, catalyst particles usually flow into the fluidized bed reactor from one side by inlet tube, which is a crucial part to transport the particles from one reactor to another one. However, the particles are not uniform distribution in inlet region of fluidized bed due to too large size of reactor and limit of internals, particularly for the catalyst cooler in FCC. The cooler is a fluidized bed with several vertical tubes to exchange heat. The uneven particles distribution in the inlet region not only impacts the heat exchange between cold tubes and hot particles but also causes the erosion and even leak of tubes. Therefore, the distribution of particles in inlet region of fluidized bed is investigated for three inlet structures in this paper. For the original structure without internal, most particles rapidly flow to the opposite region with inlet region due to particles with a high velocity. In order to improve the distribution of particles, two new structures are developed, which are made of a decelerate plate and a rectifier plate. Their decelerate plates has different slant angle, which are 15 ° and 0 ° respectively. Moreover, the rectifier plate of structure 2 is grooved. For two new structures, the particles distribution becomes more uniform and the erosion is weakened after the two inlet structures were installed, while the structure 2 has superior effect.