John C. Chen

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Professor Emeritus

Ph.D. University of Michigan, 1961
M.S. Carnegie Mellon, 1959
B.ChE. The Cooper Union, 1956

Contact Information
tel: (610) 758-4098
fax: (610) 758-5057
e-mail: jcc0@lehigh.edu

Hydrodynamics and Heat Transfer in Fluidized Beds

Fluidized beds find wide application in chemical industry as reactors, combustors, absorbers, and heat exchangers. We are interested in the complex mechanisms of multiphase flow and heat transfer in such gas-particulate systems. Experimental research is carried out in our laboratory. Currently, our program is concentrated on "fast fluidization", the regime encountered in circulating fluidized beds. Special instrumentation has been developed to characterize particle clusters. This information is used in analytical models to represent the two-phase fluid mechanics. A pseudo-continuum approach, using kinetic theory analogy, is being formulated for computer simulation of steady-state flows.

Convective Boiling and Evaporation for Chemical Processing

Many processes in the chemical industry require the vaporization or boiling of multi-component fluids. We are investigating the phenomenon of interactive fluid flow, heat transfer, and mass transfer in such processes. Two-phase flow loops are used to measure convective boiling coefficients for both single component fluids and fluid mixtures flowing in tubes and tube bundles. Other projects are studying multi-component evaporation in falling films, important for processing of specialty chemicals, food products, and polymers. With support from the chemical industry, our goal is to seek phenomenological understanding through experimentation, and to develop models for engineering design.

Environmental Technology

Multi-phase transport phenomena are encountered in a great number of environmental technologies, ranging from treatments for reduction of emissions to remediation of waste products. Our research group utilizes its expertise in multi-phase transport phenomena to aid development of various environmental technologies, including the development of alternate refrigerants to reduce ozone depletion, fluidized combustion for direct combustion of coal with in-situ capture of SO2 and fire-suppressant technology using environmentally friendly fluids.