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Magnetic determination of average catalyst temperatures in fluidized beds
Author(s) -
Cale Timothy S.,
Merson J. A.
Publication year - 1992
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690380913
Subject(s) - fluidized bed , voltage , mechanics , fluidization , permeameter , particle (ecology) , magnetic field , moment (physics) , materials science , chemistry , thermodynamics , analytical chemistry (journal) , environmental science , physics , classical mechanics , geology , chromatography , oceanography , hydraulic conductivity , quantum mechanics , soil water , soil science
A magnetic method to measure the time and spatial average temperature of supported nickel catalysts in fluidized beds is detailed. It is an extension of a magnetic method developed in this laboratory to study fixed beds. The RMS output voltage of an AC permeameter is used to follow changes in the magnetic moment, hence temperature, of the catalyst upon starting or stopping ethane hydrogenolysis. The theory of the thermometry in fluidized beds is detailed and the observed RMS output voltage vs. time traces for typical experiments are explained. Simulations indicate that signals generated by the moving particles are largely averaged out, since the direction of the magnetic moment of each catalyst particle follows the applied field and is independent of movement. Filtering in the frequency domain can be used to further reduce the effects of particle movement. Calibrations needed to convert AC permeameter output voltage changes to changes in sample temperature during experiments on two distinctly different fluidized beds are the same as for the respective fixed beds. Depending somewhat on the sample moment, the average solid temperature can be determined with a repeatability of a few tenths of a degree.