Research of glass fiber behavior in fiber length classifier.
Hopke-P; Baron-P; Deye-G; Cheng-YS
Proceedings of the AAAR 23rd Annual Conference, October 4-8, 2004, Atlanta, Georgia. Mount Laurel, NJ: American Association for Aerosol Research, 2004 Oct; :60
A fiber classifier was used to generate fibers that are monodisperse in length. It was first employed to study the influence of humidity on glass fiber behavior. The classifier configuration consists of two concentric tubular electrodes with a high voltage bipolar square wave electric field at the surface of the inner electrode. Conductive fibers placed in a gradient electric field are attracted to the inner electrode with a velocity approximately proportional to the fiber length squared. Thus, longer fibers will deposit on the inner electrode more rapidly than shorter ones. Fibers that are drawn to the inner electrode but have not been deposited, are removed in the classified flow at the bottom of the classifier. The shorter fibers not attracted to the inner electrode remain near the outer electrode. These fibers flow through a slot near the end of the outer electrode into what is termed the dump flow. Separation occurs when the aerosol containing polydisperse fibers pass between the two electrodes. An aerosol of polydisperse glass fibers was generated using an orbital fiber generator, subjected to a controlled humidity environment. Then, it was introduced into the fiber classifier as an annular flow surrounded by clean humidified air and classification percentage was measured using a particle counter over a range of relative humidity. From such observations, the influence of humidity on glass fiber behavior, especially on the process of dielectrophoresis in the classifier, was evaluated. Dielectrophoresis is the motion of a neutral object caused by an induced dipole moment in a nonuniform electric field and is sensitive to the fiber conductivity. It was believed that changing the humidity can change the conductivity of the glass fibers. Our study shows that glass fibers behave differently at extreme relative humidities.
Glass-products; Fiberglass-industry; Fiber-deposition; Aerosols; Environmental-factors; Controlled-environment; Humidity; Aerosol-particles
Proceedings of the AAAR 23rd Annual Conference, October 4-8, 2004, Atlanta, Georgia
Lovelace Biomedical & Environmental Research