Ultrasonic Filtration and Particulate Removal

Capability Title  Ultrasonic Filtration and Particulate Removal
Laboratory Los Alamos National Laboratory (LANL)
Capability experts Jim Coons
Description  

Low-energy ultrasonic separation is being developed at LANL for broad industrial application. Its fundamental construct is the removal of particles in liquid media. It cuts energy by moving particles a short distance where they meet up with other particles to form large aggregates that settle quickly to effect separation. This construct can be applied to a broad range of industrial applications such as concentrating and dewatering microalgae in seawater, removing fines from bioprocess and mineral streams, and for coalescing emulsion droplets. Emerging particle and membrane technologies can transform this construct for molecular separations as well. Molecules too small to concentrate in an ultrasonic standing wave can be adsorbed onto particles called Solid Mass Separating Agents (SMSAs). SMSAs can be tailored with high affinity for specific molecules and high responsivity to ultrasonic fields. Energetically wasteful separations cost industries billions of dollars every year, and developing energy efficient technologies is essential for US industries to remain viable in globally competitive markets. Ultrasonic separation is a low-energy technology that will serve many roles in an energy efficient future.

LANL’s ultrasonic capabilities are available to test a wide range of industrial separation challenges. Our devices are designed to address scale optimization and system performance for energy efficient removal of particulates. These ultrasonic vessels are designed for batch and continuous operation over a range of scale, to identify optimum vessel design considerations for specific particle-liquid applications. This unique set of scaling vessels is driven by a range of control and RF power options, which are also being developed for energy efficient power delivery. With these unique capabilities, LANL stands ready to address industry separation needs.

Limitations Ultrasonic separation works from density and sound speed property contrasts between particles and the liquid media. The more contrast there is, the less energy is needed for particle separation. In order for ultrasonic forces to dominate, particulate sizes between 1 and 100 microns are targeted. High temperature gradients, transient heating and convection flows in the vessel disrupts the acoustic field and aggregate settling. While piezoelectric components are known to degrade at temperatures above 200°C, LANL components are engineered to perform around room temperature.
Unique aspects LANL has extensive ultrasonic capabilities encompassing a wide range of vessel designs and application experience ranging from microalgae dewatering, chemical solids separation, lignocellulosic fines removal, and cellulosic particles removal from a variety of industrial streams. Our unique approach to system design includes scale-up, system performance assessment, and accurate radiofrequency energy measurement. LANL also has a wide range of instrumentation to measure particle/media properties impacting the performance of not only ultrasonic separators, but also more conventional process operations such as membrane filtration, centrifugation, gravity settling, and pumping. This extensive property assessment capability provides a basis for separations technology choice.
Availability LANL’s ultrasonic separation capabilities are available to support industrial partners and governmental collaborations.
Citations/references
  • 2 patents pending
  • J. E. Coons, D. M. Kalb, T. Dale, and B. L. Marrone, “Getting to Low-Cost Algal Biofuels:  A Monograph on Conventional and Cutting-Edge Harvesting and Extraction Technologies,” Algal Research 6 (2014) 250-270, DOI: 10.1016/j.algal.2014.08.005.

 

Photo of a flow-through ultrasonic vessel
Flow-through ultrasonic vessels designed for continuous operation are available at multiple scales (subset shown).

 

Photo of fours batch ultrasonic separators of different sizes
Batch ultrasonic separators are available for scaling tests (subset shown).

 

Ultrasonic separation of cellulosic fines in a small-scale ultrasonic separator.