TITLE:
Mass Transfer in a Centrifugal Turbine Agitator-Pump
AUTHORS:
Valery Katz, Gedalya Mazor
KEYWORDS:
Calcium Removal, Dispersion, Mass Transfer, Modeling, Adequacy
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.5,
April
25,
2014
ABSTRACT:
This
article is a continuation of the research, centering on a vacuum-filtration
system, which is designed to reduce the concentration of calcium in water; a
process is also known as—water softening. The problem of solving the
concentration distribution of the initial (embryonic) particles of CaCO3-particles,
which were introduced into the limited volume of the apparatus with a turbine
agitator-pump, is addressed through the use of diffusion and deterministic-stochastic
models of mass transfer. The solution of the extreme problem allows determining
the most important process parameters, such as time of dispersions
homogenization and the dispersion mass flow rate to the surface of a special
filter. For these parameters a comparative analysis of the adequacy of the
theory was found through experiments, performed in the study. We found that
uniform distribution of concentrations along the height of the apparatus is
achieved by the angular velocity of the rotation 400 rpm for the turbine with 6
- 7 blades at the time of homogenization 14s. In this case, the dispersion mass
flow to the surface of the cylindrical filter is 3 50 mg/s at an average
concentration of the introduced CaCO3 particles, which is equal to 10
g/L. We determined that the accuracy of the results depends on: the coordinates
of the material input in the apparatus volume, the surface shape of the filter
and the volumetric flow rate of the liquid (water), being discarded by the
turbine blades in the normal direction to their surface.