Measurement of combustion kinetics of a single char particle in an electrodynamic thermogravimetric analyzer

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(89)90088-6· OSTI ID:6083076

Bar-ziv, E; Jones, D B; Spjut, R E; Dudek, D R; Sarofim, A F; Longwell, J P

A new device for studying single-aerosol-particle kinetics at elevated temperatures, particularly designed for studying kinetics of gas-solid or gas-liquid combustion, is presented. The device is referred to as the electrodynamic thermogravimetric analyzer (EDTGA). An electrically charged particle is levitated by means of electrical forces. Particles of diameters of 1-250 ..mu..m can be levitated in this device. The EDTGA consists of an electrodynamic chamber with a quadrupole-type two-dimensional cross section, a heating system based on a new CO/sub 2/ laser, a temperature measurement system applying two- and three-color infrared or visible pyrometry, and a position-control system that automatically adjusts the DC voltage required to maintain the particle centered in that chamber. The EDTGA is capable of continuous or pulsed heating of the particle to temperatures exceeding 3000 K, continuous measurement of the temperature of the particle, and continuous weighing or sizing of the particle. Heating rates can exceed 10/sup 6/K s/sup -1/. The time resolution of the measurement is 0.2 ms. Two weighing methods are presented in this paper: techniques based on electron loss, and methods based on the drag force. It is shown that heating by infrared radiation causes only a minor inhomogeneity in the internal temperature field of the irradiated particle. The maximum internal temperature difference is only a few degrees in particles with temperatures exceeding 1500 K. The kinetics of oxidation of synthetic char-Spherocarb particles, in the diameter range 140-200 ..mu..m, were studied in this device. The particle's diameter, density, CO/sub 2/ surface area, and temperature were measured. The use of the EDTGA at temperatures above 1500 K is discussed.

• Research Organization: Nuclear Research Center-Negev, Beer-Sheva (IL); Dept. of Mechanical Engineering, MIT, Cambridge, MA (US); Dept. of Material Sciences and Engineering, MIT, Cambridge, MA (US); Dept. of Chemical Engineering, MIT, Cambridge, MA (US)
• OSTI ID: 6083076
• Journal Information: Combust. Flame; (United States), Vol. 75:1
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
42 ENGINEERING
CHARS
COMBUSTION KINETICS
COMBUSTION CHAMBERS
DESIGN
THERMAL GRAVIMETRIC ANALYSIS
CARBON DIOXIDE
CROSS SECTIONS
ELECTRON LOSS
EXPERIMENTAL DATA
GASES
INFRARED RADIATION
LIQUIDS
MIXTURES
OPTICAL PYROMETERS
OXIDATION
PARTICLES
SOLIDS
TEMPERATURE MEASUREMENT
TWO-DIMENSIONAL CALCULATIONS
VERY HIGH TEMPERATURE
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DISPERSIONS
ELECTROMAGNETIC RADIATION
FLUIDS
GRAVIMETRIC ANALYSIS
INFORMATION
KINETICS
MEASURING INSTRUMENTS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS PRODUCTS
PYROMETERS
QUANTITATIVE CHEMICAL ANALYSIS
RADIATIONS
REACTION KINETICS
THERMAL ANALYSIS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry
421000 - Engineering- Combustion Systems