关键词: 循环流化床, 提升管, T型弯头, 出口结构, 两相流

Abstract: The pressure drop characteristics of T-abrupt exit of the riser were analyzed based on dynamic pressure data of gas-solids two-phase flow in a circulating fluidized bed equipment by using FCC catalyst particles, and varying the operation parameters and equipment dimensions. The pressure drop of T-abrupt exit changed linearly with inlet particle density, and quadratically with inlet gas velocity. It increased significantly with the decrease of outlet tube area of T-abrupt exit. Further, the pressure drop of T-abrupt exit decreased as blind tube length increased, but changed little above a specific length, because increased blind tube length changed the pressure distribution along the upper riser. As blind tube length increased, inlet pressure of T-abrupt exit decreased, hence pressure drop decreased. There was a negative pressure zone along the upper riser and blind tube, which constrained gas-solids two-phase flow in the riser. The longer the blind tube, the longer the negative pressure zone and the greater the constraint.

Key words: circulating fluidized bed, riser, T-abrupt exit, exit configuration, two-phase flow