PRESSURIZED THERMOBALANCE APPARATUS FOR USE AT EXTREME CONDITIONS

A cold wall pressurized thermobalance was developed for obtaining thermogravimetric rate data at extreme conditions. A solid state, electronic balance was completely enclosed in a pressurized water-cooled vessel. Samples suspended from the balance were heated with an induction coil within the vessel. Design calculations indicate temperatures of 2000 K at 136 atm (2000 psi) hydrogen pressure are obtainable. Experiments were performed at sample temperatures up to 1633 K and pressures to 70 atm. Hydrogen, helium, methane, and argon were used. The measured rates were accurate to within 5 %. Signal fluctuations were correlated using the Grashof number, which reflects effects of natural convection. © 1979, American Chemical Society. All rights reserved.