TITLE: Computer Modeling of Mixing and Agglomeration in Coal Conversion Reactors. First Annual Report, 15 September 1978-31 December 1979.

AUTHOR: M. F. Scharff;   H. B. Levine;   R. K. C. Chan;   M. J. Chiou;   D. E. Dietrich.

INST.  AUTHOR: JAYCOR, Del Mar, CA.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Feb 80,  108p.

ABSTRACT:

The purpose of this contract is to develop a method for understanding mixing, pyrolysis, and agglomeration in coal conversion reactors by simulating actual reactor operating conditions with realistic, time-dependent computer calculations of the internal fluid dynamic, heat transfer, and chemical processes. Describing the evolution of stickiness and its effect on particle collisions will permit quantitative calculations of agglomeration and define regimes of satisfactory reactor operation. The first reactor under study is the Westinghouse devolatilizer unit, which is designed to avoid caking agglomeration. An axisymmetric, time-dependent simulation of the fluid dynamics has been developed and used for initial cold-flow calculations. Gas-phase chemistry has been coupled successfully to the fluid dynamics. Particle chemistry, emphasizing coal pyrolysis, has been a focus of the work, and much progress is reported. A relationship has been developed to determine whether or not two colliding, viscoelastic particles will agglomerate. The sticking probability depends, among other things, on the diameters, relative velocities, and viscosities of the particles. During the coming year, these and other modules will be coupled to produce a method for analyzing mixing and agglomeration phenomena in the Westinghouse devolatilizer unit that later can be adapted to assist in optimization and scale-up of other (caking or ash) agglomerating reactors. (ERA citation 06:000068)

CONTRACT  NUMBER: AC01-78ET10329