Experiments Using Latex Particles
Early work performed for the Subsurface Science
Program at the U.S. Department of Energy included study of the movement and
trapping of latex particles within heterogeneous mixtures of glass beads. The
picture above shows the flow cell used for the three dimensional experiments.
The tank is constructed of plexiglass for all
external walls. The experiments are run under confined conditions. To create
these conditions, the top of the cell is removeable
as shown in the top photo. After packing, the top can be attached as in the
bottom photo.
The tank consists of three sections. Two are reservoirs and one is the region
of the experimental medium. The experimental medium is placed in the large
region in the center of the cell. The screens which appear as grey surfaces in
these photos separate the experimental medium from the two reservoirs. The
reservoirs, then, are the regions between the left and right ends of the cell
and these gray screens.
The screens themselves are made of a white plastic lattice (seen most clearly
on the top and bottom of the tank in the upper photo) to which an 80 mesh
stainless steel screen has been attached (it is attached by melting the screen
into the lattice at several points using a soldering iron). The screens are
held in place with silicon glue. The white lattice is used on the top and
bottom of the tank to prevent short circuiting along these surfaces.
It might be noticed that there are a series of ports on the inflow and outflow
reservoirs. The purpose of these multiple ports is to allow injection of fluid
at a constant rate (through the center port), while mixing the reservoir to
ensure that concentration within the reservoir is uniform (mixing accomplished
with the four remaining ports).
Details of our results from the particle tracer tests may be found in two
papers published on this work. These are:
Silliman, 1995,"Paritcle transport through two-dimensional, saturated
porous media: influence of physical structure of the medium", Journal of
Hydrology, 167, 79-98.
Silliman, 1996, "The importance of the third dimension on transport
through saturated porous media: case study based on transport of
particles", Journal of Hydrology, 179, 181-195.