Holdup correlations in slurry-solid fluidized beds

The use of slurry-solids fluid beds plays an important role in the development of synthetic fuels and the hydrogen processing of petroleum resids. In the H-Coal process in particular, coal oil slurries are processed over extrudates of hydrodesulfurization catalyst. The objective of this note is to present a model which describes the volume fraction occupied by the slurry phase. The accurate prediction of the liquid holdup is important not only for the calculation of the bed height in liquid solid fluidized beds, but also is required for the development of a model predicting the holdup in three-phase fluidized beds. In the present publication, the application of two different correlations is considered: (1) the Richardson and Zaki; and (2) Ramamurthy and Sabbaraju

Cold flow model for the H-Coal reactor. Part II. Data correlations

Experiments at ambient temperatures with extrudates of desulfurization catalyst fluidized with mixtures of nitrogen and coal char/kerosene slurries are used to simulate the fluid dynamics of the H-Coal reactor at actual operating conditions. Data from these studies presented in Part I are used to establish the validity of a model giving the volume fraction occupied by the gas, the slurry, and the catalyst phase. The importance of bubble terminal velocity and solids holdup in the gas wake volume in explaining bed contraction is discussed