(Acoustic Barrier Particulate Separator)
The acoustic barrier particulate separator separates particulates in a high temperature gas flow. The separator produces an acoustic waveform directed against the gas flow, causing particulates to move opposite the flow. The particulates drift to the wall of the separator, where they aggregate with other particulates and precipitate into a collection hopper. The acoustic barrier particulate separator differs from other separators by combining both high efficiency and high temperature capabilities.
The figure below presents a conceptual design. High temperature inlet gas flows through a muffler chamber and an agglomeration segment before entering the separation chamber. In the separation chamber, particulates stagnate due to the acoustic force and drift to the chamber wall, where they collect as a dust cake that falls into a collection hopper. The solids are transported from the collection hopper by a screw-type conveyor against a clean purge gas counterflow. The purge gas cools the solids and guards against contamination of particulates by inlet-gas volatiles in the process stream.
The gas flows past the acoustic source and leaves the separation chamber through an exit port. The gas then passes through another muffler chamber and flows through sections where it is cooled and any remaining gas-borne particulate samples are collected. Finally, the gas is further scrubbed or filtered as necessary before it is discharged.
The separator can remove the entire range of particle sizes; it has a removal efficiency of greater than 90 percent for submicron particles and an overall removal efficiency of greater than 99 percent. Due to the large diameter of the separator, the system is not prone to fouling.
This technology can treat off-gas streams from thermal desorption, pyrolysis, and incineration of soil, sediment, sludges, other solid wastes, and liquid wastes. The acoustic barrier particulate separator is a high-temperature, high-throughput process with a high removal efficiency for fine dust and fly ash. It is particularly suited for thermal processes where high temperatures must be maintained to prevent condensation onto particulates. Applications include removal of gas-borne solids during thermal treatment of semivolatile organics, such as polychlorinated biphenyls, and gas-phase separation of radioactive particles from condensible hazardous materials.
The acoustic barrier particulate separator was accepted into the SITE Emerging Technology Program in 1993. The principal objective of this project will be to design, construct, and test a pilot-scale acoustic barrier particulate separator that is suitable for parallel arrangement into larger systems. The separator will be designed for a flow of 300 cubic feet per minute and will be tested using a simulated flue gas composed of heated gas and injected dust.
EPA PROJECT MANAGER:
Ronald Lewis
U.S. EPA
National Risk Management Research Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
513-569-7856
Fax: 513-569-7105
TECHNOLOGY DEVELOPER CONTACT:
Robert Goforth
General Atomics
Nuclear Remediation Technologies Division
MS 2/633
P.O. Box 85608
San Diego, CA 92186-9784
619-455-4057 or 619-455-2984
Fax: 619-455-3233