Date of Award

2000

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemical Engineering

First Advisor

Arthur M. Sterling

Abstract

Gas-solid fluidization is a subject having wide engineering applications overlapping different industries. A relatively unique application of fluidized bed technology resulted from a convergence of medical studies of thromboresistant materials with engineering development of gas impermeable and corrosion resistant coatings for artificial heart valves. The objective of this research was to study, through experimental measurements, gas-particle hydrodynamic behavior in the spouted bed, with an emphasis on biomedical manufacturing of prosthetic heart valves. Laboratory-scale and pilot-scale experiments were conducted to investigate the gas and solid phase behavior, such as minimum spouting velocity, pressure profile, particle velocity profile and particle density distribution. Gas phase hydrodynamics at different temperature were compared using two different physical models. Pressure fluctuation phenomena was also studied and related to the behavior of bed and gas-solid mixing. Experimental results were very promising. Pressure, particle velocity, and particle density distribution data will be further used to verify the numerical model. And they will also be used to direct the operation in the production unit of Sulzer Carbomedics Inc. Using a half-column model, stability of the spouted bed was analyzed both visually and using the pressure fluctuation analysis. Results showed that the reactor being used for pyrolitic coating of heart valve parts at Carbomedics Co., with the geometry of standard inlet and 40° of the cone angle, is operated at in the unstable regime. The geometry of the reactor plays an important role in determining the stability of the spouted bed. Experimental results also showed that the wall effect in the half-column model has negligible effect on the gas and solid phase behavior.

ISBN

9780599905986

Pages

119

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