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Title: Determining inert content in coal dust/rock dust mixture

Abstract

A method and apparatus for determining the inert content of a coal dust and rock dust mixture uses a transparent window pressed against the mixture. An infrared light beam is directed through the window such that a portion of the infrared light beam is reflected from the mixture. The concentration of the reflected light is detected and a signal indicative of the reflected light is generated. A normalized value for the generated signal is determined according to the relationship .phi.=(log i.sub.c `log i.sub.co) / (log i.sub.c100 -log i.sub.co) where i.sub.co =measured signal at 0% rock dust i.sub.c100 =measured signal at 100% rock dust i.sub.c =measured signal of the mixture. This normalized value is then correlated to a predetermined relationship of .phi. to rock dust percentage to determine the rock dust content of the mixture. The rock dust content is displayed where the percentage is between 30 and 100%, and an indication of out-of-range is displayed where the rock dust percent is less than 30%. Preferably, the rock dust percentage (RD%) is calculated from the predetermined relationship RD%=100+30 log .phi.. where the dust mixture initially includes moisture, the dust mixture is dried before measuring by use of 8 to 12 meshmore » molecular-sieves which are shaken with the dust mixture and subsequently screened from the dust mixture.« less

Inventors:
 [1];  [2]
  1. (Finleyville, PA)
  2. (Oakmont, PA)
Publication Date:
Research Org.:
National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV
OSTI Identifier:
866828
Patent Number(s):
US 4799799
Assignee:
United States of America as represented by Secretary of (Washington, DC) NETL
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
determining; inert; content; coal; dust; rock; mixture; method; apparatus; transparent; window; pressed; infrared; light; beam; directed; portion; reflected; concentration; detected; signal; indicative; generated; normalized; value; determined; according; relationship; phi; log; c100; -log; measured; 100; correlated; predetermined; percentage; determine; displayed; 30; indication; out-of-range; percent; preferably; calculated; initially; moisture; dried; measuring; 12; mesh; molecular-sieves; shaken; subsequently; screened; measured signal; transparent window; generated signal; dust mixture; infrared light; rock dust; light beam; reflected light; signal indicative; coal dust; inert content; /356/250/

Citation Formats

Sapko, Michael J., and Ward, Jr., Jack A.. Determining inert content in coal dust/rock dust mixture. United States: N. p., 1989. Web.
Sapko, Michael J., & Ward, Jr., Jack A.. Determining inert content in coal dust/rock dust mixture. United States.
Sapko, Michael J., and Ward, Jr., Jack A.. Sun . "Determining inert content in coal dust/rock dust mixture". United States. https://www.osti.gov/servlets/purl/866828.
@article{osti_866828,
title = {Determining inert content in coal dust/rock dust mixture},
author = {Sapko, Michael J. and Ward, Jr., Jack A.},
abstractNote = {A method and apparatus for determining the inert content of a coal dust and rock dust mixture uses a transparent window pressed against the mixture. An infrared light beam is directed through the window such that a portion of the infrared light beam is reflected from the mixture. The concentration of the reflected light is detected and a signal indicative of the reflected light is generated. A normalized value for the generated signal is determined according to the relationship .phi.=(log i.sub.c `log i.sub.co) / (log i.sub.c100 -log i.sub.co) where i.sub.co =measured signal at 0% rock dust i.sub.c100 =measured signal at 100% rock dust i.sub.c =measured signal of the mixture. This normalized value is then correlated to a predetermined relationship of .phi. to rock dust percentage to determine the rock dust content of the mixture. The rock dust content is displayed where the percentage is between 30 and 100%, and an indication of out-of-range is displayed where the rock dust percent is less than 30%. Preferably, the rock dust percentage (RD%) is calculated from the predetermined relationship RD%=100+30 log .phi.. where the dust mixture initially includes moisture, the dust mixture is dried before measuring by use of 8 to 12 mesh molecular-sieves which are shaken with the dust mixture and subsequently screened from the dust mixture.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1989},
month = {1}
}

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