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RECORD NUMBER: 267 OF 453

OLS Field Name OLS Field Data
Main Title Modification and Characterization of Dry Material Feeder Delivery of Red and Violet Dye Mixtures.
Author Higuchi, M. A. ; Steinhagen, W. H. ;
CORP Author ManTech Environmental Technology, Inc., Research Triangle Park, NC. ;Alltech Associates, Inc., Cary, NC.;Health Effects Research Lab., Research Triangle Park, NC.
Publisher c1991
Year Published 1991
Report Number EPA-68-02-4450; EPA/600/J-91/112;
Stock Number PB91-207050
Additional Subjects Aerosol generators ; Feed mechanisms ; Azo dyes ; Anthraquinones ; Dyes ; Mixtures ; Dusts ; Exposure chambers ; Performance testing ; Statistical analysis ; Precision ; Design ; Reprints ; Inhalation toxicology
Holdings
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Status
NTIS  PB91-207050 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 11/26/1991
Collation 15p
Abstract Uniform delivery of dry material for stable concentrations of aerosols in inhalation exposure chambers is essential in inhalation experiments. The paper characterizes an AccuRate dry material feeder with modifications, for different helix sizes, actuation rates, nozzle types and dye mixtures. The basic design of the AccuRate dry material feeder used to deliver precise quantities of dye mixtures is inadequate for aerosol exposure research. To improve delivery, a push-pull type solenoid was mounted to the feeder and connected to a microprocessor controlled timer for actuation. Without the actuator, the coefficient of variability increased with smaller size helixes and reached 35, 34 and 121% for 1/2, 3/8, and 1/4 inch helixes, respectively. With the actuator, the coefficient of variability was reduced to 2.5, 4.8 and 8.8% for the same helix sizes and red dye mixture. The optimum actuation rate was determined to be 90 cycles/min. The use of the stainless steel nozzle improved feed rates by presumably limiting any additional amount of electrostatic charge on dye particles. The modification, addition of actuator with rate of 90 cycles/min to the AccuRate feeder greatly decreased the amount of variability in feed rates for all helixes and dye mixtures, while increasing the dye flow rates. The modification is recommended when dry material characteristics are such that accuracy and precision of feed rates cannot be optimized. (Copyright (c) 1991 by Hemisphere Publishing Corporation.)
Supplementary Notes Pub. in Inhalation Toxicology, v3 p223-235 Mar 91. Prepared in cooperation with Alltech Associates, Inc., Cary, NC. Sponsored by Health Effects Research Lab., Research Triangle Park, NC.
NTIS Title Notes Journal article.
Title Annotations Reprint: Modification and Characterization of Dry Material Feeder Delivery of Red and Violet Dye Mixtures.
Category Codes 68G; 57Y
NTIS Prices PC A03/MF A01
Primary Description 600/10
Document Type NT
Cataloging Source NTIS/MT
Control Number 124123322
Origin NTIS
Type CAT