Solid circulation around a jet in a fluidized-bed gasifier
Abstract
Particle circulation in the jet region of a fluidized bed gasifier is analyzed. Particle velocities were measured at corresponding points within a jet in the two dimensional bed, using the optical fiber probe and a Laser Doppler Velocimeter (LDV). The probe measurements compare well with the LDV results in the main jet region. Particle velocities were also measured with the probe in the dense phase region of the fluidized bed where measurements were not possible using LDV. The resulting flow maps clearly indicate solids circulation patterns around jets and identify dead zones formed on the distributor plate. The entering gas jet was modeled assuming that the dense phase is entrained into the gas stream. The solid particles are then conveyed upwards along the jet penetration distance. Typical conditions for a fluidized bed combustor were used and the model includes the reactions between carbon and carbon monoxide. The results indicate that considerable reaction occurs in the gas jets entering the reactor and that they should be considered in any careful analysis of its operation.
- Publication:
-
Final Report Lehigh Univ
- Pub Date:
- April 1981
- Bibcode:
- 1981lehi.rept.....C
- Keywords:
-
- Circulation;
- Fluidized Bed Processors;
- Gas Jets;
- Coal Gasification;
- Laser Doppler Velocimeters;
- Mathematical Models;
- Particles;
- Velocity;
- Fluid Mechanics and Heat Transfer