Pacific Northwest National Laboratory (PNNL) scientists have invented an ingenuous yet simple particle separation technology to clean up any legacy radioactive waste from nuclear weapons production.
According to the scientists, the said technology not only decreases the time and money needed for radiological tank waste or fracing fluids cleanup, it could also benefit other industrial applications such as food processing, advanced manufacturing, aerosol science, supercritical fluids, oil and gas, and environmental waste processing.
The patent-pending 3D printed filter design is based on a ‘mesofluidic separations’ process that removes different sized particles out of slurried substances at a phenomenal 90 gallons per minute!
It is exceptionally cost effective and can operate for much longer periods and at lower operating pressures than classic dead-end filters and cross-flow filters before the inevitable plugging.
In tests, the PNNL team utilized buckets of granular oxides mixed with water into a slurry to simulate radioactive waste. This bench-scale demonstration maintained 94% flow over seven hours with no work stoppage from clogging.
Furthermore, the tests worked at a rate of 90 gallons per minute through a three-inch pipe, which is an optimal flow for industrial operations.
According to lead inventor Leonard Pease, the cleverly designed separation system—nicknamed “pachinko” by the team—resembles a series of hollow hockey pucks filled with rows of individual posts.
Each row of descending posts is slightly offset from the row above and this allows them to create unique flow fields that cause larger particles to move in the desired direction.
Pease contends in a full-scale system, multiple sets of pucks with different post designs could guide particles to their own ‘express lane’, separating relatively large pieces (about the size of a lemonhead candy) down to 20 microns (the size of a white blood cell).
“You gain economies of scale without adding more costly infrastructure,” says Pease, alluding to how the pucks can be stacked one behind the other.
What’s more, the separator works in both horizontal and vertical mode, including top-down and bottom-up flows, making it all the more appealing for broad industrial uses.
Image and content: Andrea Starr/Pacific Northwest National Laboratory