skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Photothermal method of determining calorific properties of coal

Abstract

Predetermined amounts of heat are generated within a coal sample (11) by directing pump light pulses (14) of predetermined energy content into a small surface region (16) of the sample (11). A beam (18) of probe light is directed along the sample surface (19) and deflection of the probe beam (18) from thermally induced changes of index of refraction in the fluid medium adjacent the heated region (16) are detected. Deflection amplitude and the phase lag of the deflection, relative to the initiating pump light pulse (14), are indicative of the calorific value and the porosity of the sample (11). The method provides rapid, accurate and non-destructive analysis of the heat producing capabilities of coal samples (11). In the preferred form, sequences of pump light pulses (14) of increasing durations are directed into the sample (11) at each of a series of minute regions (16) situated along a raster scan path (21) enabling detailed analysis of variations of thermal properties at different areas of the sample (11) and at different depths.

Inventors:
 [1]
  1. (Berkeley, CA)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
865583
Patent Number(s):
US 4540285
Assignee:
United States of America as represented by United States (Washington, DC) LLNL
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
photothermal; method; determining; calorific; properties; coal; predetermined; amounts; heat; generated; sample; 11; directing; pump; light; pulses; 14; energy; content; surface; region; 16; beam; 18; probe; directed; 19; deflection; thermally; induced; changes; index; refraction; fluid; medium; adjacent; heated; detected; amplitude; phase; lag; relative; initiating; pulse; indicative; value; porosity; provides; rapid; accurate; non-destructive; analysis; producing; capabilities; samples; preferred; form; sequences; increasing; durations; series; minute; regions; situated; raster; scan; path; 21; enabling; detailed; variations; thermal; depths; predetermined energy; sample surface; calorific value; pump light; thermally induced; surface region; probe beam; light pulses; method provides; fluid medium; preferred form; light pulse; predetermined amount; method provide; thermal properties; energy content; scan path; phase lag; probe light; predetermined amounts; raster scan; coal samples; coal sample; minute region; minute regions; photothermal method; /356/374/

Citation Formats

Amer, Nabil M. Photothermal method of determining calorific properties of coal. United States: N. p., 1985. Web.
Amer, Nabil M. Photothermal method of determining calorific properties of coal. United States.
Amer, Nabil M. Tue . "Photothermal method of determining calorific properties of coal". United States. https://www.osti.gov/servlets/purl/865583.
@article{osti_865583,
title = {Photothermal method of determining calorific properties of coal},
author = {Amer, Nabil M.},
abstractNote = {Predetermined amounts of heat are generated within a coal sample (11) by directing pump light pulses (14) of predetermined energy content into a small surface region (16) of the sample (11). A beam (18) of probe light is directed along the sample surface (19) and deflection of the probe beam (18) from thermally induced changes of index of refraction in the fluid medium adjacent the heated region (16) are detected. Deflection amplitude and the phase lag of the deflection, relative to the initiating pump light pulse (14), are indicative of the calorific value and the porosity of the sample (11). The method provides rapid, accurate and non-destructive analysis of the heat producing capabilities of coal samples (11). In the preferred form, sequences of pump light pulses (14) of increasing durations are directed into the sample (11) at each of a series of minute regions (16) situated along a raster scan path (21) enabling detailed analysis of variations of thermal properties at different areas of the sample (11) and at different depths.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1985},
month = {1}
}

Patent:

Save / Share: