Degree Type

Dissertation

Date of Award

1989

Degree Name

Doctor of Philosophy

Department

Agricultural and Biosystems Engineering

First Advisor

Dwaine S. Bundy

Abstract

The objectives were to develop and evaluate a practical dust removal method for livestock housing using electrostatic precipitation techniques. Laboratory and animal housing studies were conducted;High voltage negative ionizing electrodes and positive collectors were used to charge and remove airborne dust particles from the air. Different negative ionizing electrodes, protective enclosures, and collectors were investigated in the laboratory. Ionizing equipment was compared in a test chamber with a measured dust sample introduced into the chamber before each trial. Particle count data were collected;Needlepoint and wire ionizing electrodes were compared and no significant difference was found between dust decay rates. Because of the electrical shock hazard with high voltage electrodes, protective enclosures with and without forced air movement were investigated. Enclosure type affected the level of corona discharge and ion distribution. Ion distribution was controlled by the electric field forces rather than movement of the forced air. Therefore, a 58% open plastic mesh protective enclosure was used. Area tube collectors with and without an insulating coating to reduce the shock hazard were also investigated. The coating reduced the dust removal rate by about 24%;Prototype tests were conducted in an animal production unit to obtain a quantitative estimate of dust removal under typical operating conditions. Two animal chambers with similar ventilation, temperature control, and management were used. Each chamber housed 48 nursery pigs;Particle count and mass samples were collected. Particle size ranges collected were the same between the animal study and laboratory study--0.5-1.0 micron, 1.0-2.0 micron, 2.0-5.0 micron, 5.0-10.0 micron, and greater than 10.0 micron. Mass samples were taken with a 0.8 micron filter and vacuum pump. All systems evaluated in this study resulted in a significant reduction in airborne dust concentration. Without ionization, typical particle counts were between 76 and 169 million particles per cubic meter (mppcm). With ionization dust control, particle counts were between 38 and 86 mppcm. Percent reductions of 57% to 66% of all dust particles were achieved with ionization. Comparing particle count and mass data indicates that particles greater than 2.0 micron are removed more effectively than particles less than 2.0 micron.

DOI

https://doi.org/10.31274/rtd-180813-12816

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Michael Alan Veenhuizen

Language

en

Proquest ID

AAI9114498

File Format

application/pdf

File Size

187 pages

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