Model for solids flow rate through loop seal in a circulating fluidized bed

A model for calculating the solids flow rate through the U-type loop seal in the circulating fluidized bed (CFB) was derived by combining the relationships for the solids flow rate in the recycle chamber and downcomer. The downcomer was considered as a transitional packed bed (TPB) and the recycle chamber as a bubbling fluidized bed (BFB). Ergun equation was applied to the downcomer and equations derived in our previous study for the solids flow rate to the recycle chamber. In estimating the mass flux of solids in the recycle chamber, it was reasonable to consider the effect of the relative velocity of gas to solid. Equations which included the effect of solids velocity were proposed for the superficial relative velocity of gas to solid, volume flux of bubble, and mass flux of solids in the recycle chamber. This model well predicted the solids flow rate in the loop seal. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.