Figure 3 . Images of the
AMPH device at 1x (left), 20x (center), and 235x (right) magnification.
The width of the octagonal device is 27 mm. The column is comprised of
an internal solid framework surrounded by a solid outer shell. The
framework is built of porous walls that are ~150 μm
thick. The framework has a hexagonal honeycomb-like structure, and in
the vertical direction it follows an undulating pattern to minimize the
possibility of liquid droplets falling through the device without
interacting with the wicking structures. This undulation generates the
wave-like surface of the outer shell (Figure 1 (C)).
The column was first designed in CAD software (SolidWorks 2019) and then
manufactured via an additive printing process that employs direct metal
laser sintering: a laser melts metal powder one layer at a time,
gradually building on previous layers until the entire structure is
completed. The internal honeycomb is a high-porosity metal scaffold
created by scanning the laser quickly and at a heat intensity that is
too low to completely melt the metal powder. The solid outer shell is
made with laser power and scan settings that produce high-density,
non-permeable metal. The manufacturing was performed by
i3DMFGTM and printed with nickel-based Inconel 625
using custom print settings.
Distillation System
The distillation system consists of a microchannel recuperator to
precool the incoming air, a custom condenser that attaches to the cold
head of the stirling cryocooler, the distillation column, and a vacuum
can that contains these components and provide thermal insulation. The
same vacuum can, condenser, and recuperator were used for all
experiments, with the distillation column being changed for each set of
tests. The system configuration is shown in Figure 4.