CFD analysis of turbulent slurry flow through the sensing region of near IR diffuse transmission and reflectance probes mounted in a pipe flow.

摘要

Scope and method of study. In the current research, CFD analysis of a chemical slurry consisting of liquid Xylene flowing with 2 amino, 4, 6 dimethyl pyrimidine (ADP) particles in a pipe has been considered primarily. Some cases of comparison of slurries of ADP-Xylene and CaC03-water are also considered. The diameter of the pipe is 0.0508 m. The length to diameter ratio of the pipe is 70. A geometric model of an FTIR/NIR probe is mounted asymmetrically on the wall of the pipe and major concentration was given to the flow in the sensing region of the probe. Fluent (Ansys) has been employed as the simulation software to predict the end results of the flow. K-epsilon Turbulence model and mixture multiphase model are employed for analysis. Particle sizes of 100 and 400 microns are considered and a comparative study is done based on variation in particle size.;Findings and conclusions. In the probe vicinity, fluctuations are observed in axial velocity profiles along the centerline and the axes parallel to centerline and passing through probe sensing region. Axial velocity profiles are analyzed along vertical axes at different axial position. These profiles hold fair agreement with the literature. Particle volume fraction profiles are analyzed along different axes parallel to x, y and z directions but lying in the probe sensing region. It has been noticed that variation in particle volume fraction magnitude is negligible. Thus volume fraction is nearly constant in the probe sensing region. The particle volume fraction for 100 and 400 micron particles size are compared along the axes in the sensing region of the probe. It has been found that 100 micron particles have higher particle volume fraction magnitudes than 400 micron particles. This is in good agreement with literature. Axial velocity profiles of ADP-Xylene slurry is compared with that of CaC03-water slurry. The axial velocity of ADP particles is found to be higher than that of CaC03 particles due to density difference between the particles. This agrees well with the literature.