Dr. J.S. Chang

Dr. J.S. Chang

Professor Emeritus
Department of Engineering Physics

McMaster University
1280 Main Street West, Hamilton
Ontario, Canada  L8S 4L7

B.Eng , B.Edu.Eng., M.Eng. (Musashi Int. of Tech.), Ph.D. (York)

 

In Memory of Professor J.S. Chang

Research Interests

Integrated Electrostatic-Non-Thermal Plasma Flue Gas Cleaning Systems

NOx and SOx emissions from coal and oil power stations are the major causes of acid rain. CO 2, N 2O and CH4 emissions cause a greenhouse effect which leads to abnormal heating, and can create a temperature inversion layer that traps pollutants. There is a vital interest in controlling these emissions - near term for acid rain and long term for the greenhouse effect.

Canada is committed to reducing the level of acid gas and toxic emissions from its coal burning plants. The options being considered to meet the stringent gas regulations include: fuel switches, installing wet Flue Gas Desulphurizers (FGD), in-furnace sorbent injection, catalyst reduction and electron beam or corona plasma processes.

The objective of the program is to develop a cost effective way of operating existing electrostatic precipitators (ESP) with specially designed prechargers and/or pulse energization when used to collect high resistivity ashes and ultrafine particles (toxic emissions).  NOx, SOx, and volatile organic compounds in flue gases will be removed by a flow stabilized corona discharge plasma reactor or/and electron-beam reactors.  

The goal of the project will be to obtain sufficient information to upgrade existing gas cleaning systems to integrate flue gas cleaning systems which consists of an in-furnace electrohydrodynamic (EHD) sorbent or agent injection system, pulse-energization of ESP's, corona discharge induced plasma reactor, and pulse energized cold prechargers. Laboratory experiments and a pilot plant scale test will be conducted.

Nuclear Reactor Thermalhydraulics, Electromagnetic Hydrodynamics, and Two-Phase Flow Diagnostics

Involved in research related to the safety of nuclear reactor primary heat transport system (PHT) for both fission and fusion power plants. Fission reactor safety topics include the reactor heat transfer and fluid dynamics in postulated accidents, the transient response of PHT systems under plant operation, and the monitoring and diagnostics of two-phase flow in CANDU, Advanced PWR and MAPLE reactors.

Two-phase flow diagnostics by a real-time ultrasonic, thermo image, neutron radiography, and electric method are also being developed.

The goal of the project will be a development of three-dimensional high speed two-phase flow imaging techniques.  McMaster Nuclear Reactor was used as a neutron source in the project.

Fusion reactor topics include the investigation of the electromagnetic field (EMF) effect on the PHT system in gas-liquid, gas-powder and gas-liquid metal two-phase flow. The results also applied to evaluate the "Lightning and Nuclear EMP" protection of nuclear power plant PHT system. Thermalhydraulics design and tests of ITER fusion reactor test facility is under investigations.

Water, Liquid and Solid Waste Treatments by Thermal Plasmas

Drinking and waste water treatments were mainly conducted by chemical methods.   However, more recently, the cost effective and efficient techniques based on the plasma technologies, such as ozone injection (the remote plasma technique), UV irradiations (the indirect plasma technique) etc., were commercialized.  In this project, the advanced direct plasma water treatments based on the pulsed arc electrohydraulic discharge technique will be developed for the removal of toxic metals, VOC's, TOC's, POP's and Nitrogen compounds from the water to improve BOD as well as sterilization.

In the project of thermal plasma solid and liquid waste treatments, the high temperature (up to 20,000K) generated by dc plasma torches will be actively used to treat used automobile tires, plastics, incineration bottom and fly ashes from municipal waste and sludges for de-toxifications and recycle to construction materials.  In this project, neutron activation analyses based on McMaster Nuclear Reactor, and McMaster Accelerator were used for the trace composition analyses.

Publications

K. Uchimura, G.D. Harvel, T. Matsumoto, M. Kanzaki and J.S. Chang, "An Image Processing Approach for Two-Phase Interface Visualized by a Real Time Neutron Radiography Technique", J. Flow Measurement & Instrumentation, 9, 203-210 (1999).

J.Y. Park, I. Tomcic, G.F. Round and J.S. Chang, Simultaneous Removal of NOx and SO2 from N2-O2-CO2 Mixture Gases by Corona Radical Shower Systems, J. Phys. D.: Appl. Phys. 32, 1006-1018 (1999).

K. Urashima, J.S. Chang, J.Y. Park, D.C. Lee, A Chakrabarti and T. Ito, "Reduction of NOx from Natural Gas Combustion Flue Gases by Corona Discharge Radical Injection Techniques", Trans. IEEE Industry Appli. Soc., 34, 934-939 (1998).

S. Kanazawa, J.S. Chang, G.F. Round, G. Sheng, T. Ohkubo, Y. Nomoto and T. Adachi, "Removal of NOx from Flue Gas by Corona Discharge Activated Methane Radical Showers", J. Electrostatics,  40 & 41, 651-656 (1997).

 J.S. Chang, A. Chakrabarti, T.A. Myint and A. Miziolek, "Removal of Carbon Tetrachloride from Air Stream by a Corona Torch Plasma Reactor", Japanese J. Appl. Phys., 36, 5018-5024 (1997).

C.N. Norris, J.S. Cotton, M. Shoukri, T. Smith-Pollard and J.S. Chang", Electrohydrodynamic Effects on Flow Redistribution and Convective Boiling in Horizontal Cocentric Tubes under High Inlet Quality Conditions, ASHRE Trans:Research, 4228, 222-236 (1999).

G.D. Harvel, K. Hori, K. Kawanishi and J.S. Chang, "Cross- sectional Averaged Void Fraction Distribution Measurements in a Vertical Annulus Two-Phase Flow by Real Time Neutron Radiography and X-Ray Computed Tomography Techniques", Flow Measurement and Instrument, 10, 134-153 (2000).

J.S. Chang, B.W. Gu, P.C. Looy, F.Y. Chu and C.J. Simpson, "Thermal Plasma Pyrolysis of Used Old Tires for Production of Syngas", J. Environmental Sci. & Health, A31, 1781-1799 (1996).

J.S. Chang, P.C. Looy, K. Nagai, T. Yoshioka, S. Aoki and A. Maezawa, "Preliminary Pilot Plant Tests of a Corona Discharge-Electron Beam Hybrid Combustion Flue Gas Cleaning System", IEEE Trans. Industry Application, 32, 131-137 (1996).

A. Zukeran, P.C. Looy, A. Chakrabarti, A.A. Berezin, S. Jayaram, J.D. Cross, T. Ito and J.S. Chang, "Collection Efficiency of Ultrafine Particles by an Electrostatis Precipitator Under DC and Pulse Operating Modes", Trans. IEEE Industry Appl. Soc., 35, 1184-1191 (1999).