Heat transfer studies of packed bed coal liquefaction reactors

The effective thermal conductivity (K/sub e/) and wall heat transfer coefficient (H/sub w/) were determined in a packed bed reactor model over a range of gas mass velocities from 0 to 15,000 kg/m/sup 2/ hr, liquid mass velocities from 5000 to 65,000 kg/m/sup 2/ hr, and pressures that simulate coal liquefaction pressures from 1000 to 4000 psig. A correlation for K/sub e/ and H/sub w/ was developed for the range of study. Several mathematical models for one and two dimensions, and for one and two parameters, were derived to describe two-phase flow in packed beds. Two flow regimes are described. The entrance effects for the low liquid flow regime seem to be limited to a length of about ten diameters, while the entrance effects for the high liquid flow seem to extend through the entire length of the column.