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:
-
- Berkeley, CA
- Issue Date:
- Research Org.:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- OSTI Identifier:
- 865583
- Patent Number(s):
- 4540285
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01N - INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- 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 = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}