Thermal Phase Separation
A senior year Mechanical
Engineering Design Project completed in April, 1997.
of Nova Scotia
Halifax, Nova Scotia,
Group: Derek Bent, Ross Blakeney,
Peter D. Lewis, and Sandra MacAulay
Supervisor: Dr. Feridun Hamdullahpur,
B.Sc., M.Sc. (Tech. Univ. of Istanbul), Ph.D. (TUNS), P.Eng. Dean of Graduate
Studies and Research, TUNS
Environmental Dartmouth, Nova Scotia
Thermal Phase Separation (TPS) is an advanced thermal desorption
process used for the treatment of soils and sludges contaminated with
chlorinated hydrocarbons such as PCBs. The TPS is a two-stage process.
The first stage is the separation process where the organics are removed
from the soil or sludge. The second stage involves the clean-up and treatment
of air, water, and contaminates. This project involves examining the existing
TPS unit and recommending changes that improve the overall efficiency of
the system. The two main target areas were the gas and water cleanup systems.
Within these systems a few main components were identified and redesigned
to optimize their performance.
Areas of Focus
Cooling of the discharge soil.
A heat exchanger was recommended to improve soil cooling
after the thermal desorption process. This heat exchanger was an auger
assembly with a cooled jacket and internally cooled auger flights.
It was recommended that a cyclone be placed in the lines
transporting the hot gasses from the desorption chamber. The cyclone will
remove dust from the line and prevent it from entering the quench chamber.
Cooling of gases from the desorption chamber.
Several changes were recommended for the quench which
cools these hot gasses. The changes include new spray nozzles, a static
mixer, and mist elimination baffles. The changes will improve the efficiency
of the quench process.
Liquid sludge separation.
The liquid / sludge separation holding box was redesigned
to improve the separation efficiency.
These recommendations will improve the efficiency of the TPS process
and reduce operational costs.
to Design Projects 1996-1997