TITLE: Gas/Slurry Flow in Coal-Liquefaction Processes (Fluid Dynamics in 3-Phase Flow Columns). Quarterly Technical Progress Report, 1 April 1980-30 June 1980.

AUTHOR: D. H. S. Ying;   R. Sivasubramanian;   E. N. Givens.

INST.  AUTHOR: Air Products and Chemicals, Inc., Allentown, PA.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Aug 80,  54p.

ABSTRACT:

This work is a continuation of 3-phase flow to support the  design of the 6000 T/D dissolver for the SRC-I demonstration plant. The 6000 T/D SRC-I demonstration plant will employ verticle tubular rectors feeding slurry and gas concurrently upward through these vessels. This reactor is essentially an empty vessel with only a distributor plate located near the inlet. Because the commercial plant represents a considerable scale-up, this program is addressing the need for additional data on behavior of three phase systems in large vessels. Parameters are being studied at conditions that relate directly to the projected demonstration plant operating conditions. Gas velocity is the key element to maintain solid particles in suspension. Above the critical gas velocity, defined as the minimum gas velocity to achieve full solids suspension, solid accumulation is practically independentt of gas velocity; however, it increases linearly with decreasing liquid velocity at a fixed gas input rate. The effect of liquid and gas velocities on solids accumulation was studied in a 5-inch diameter column using 60/80 mesh sand particles. The mass transfer coefficient, k/sub L/a, is reduced by 30% in the presence of solids at all gas velocities. Batch and continuous experiments were conducted to study oxygen transfer in air/water and air/water/sand systems. Results from the 5-inch diameter column show that k/sub L/a increases with gas velocity in both 2-phase and 3-phase systems. The results also indicate that the k/sub L/a is independent of column height for the 5-inch diameter column. The effect of the absence of a distributor on fluid dynamics could not be clearly determined because of an unusual liquid level surge behavior. Results from liquid dispersion experiments confirm the earlier conclusion that liquid velocity has no effect on axial dispersion coefficients. (ERA citation 06:016353)

      CONTRACT  NUMBER: AC01-79ET14801