Apparatus for Controlled Hydrodynamic Electrochemical and Corrosion Studies in High-Temperature Aqueous Systems⁽¹⁾ Available to Purchase

An apparatus for performing electrochemical and corrosion studies in aqueous environments at elevated temperatures (25 to 250 C) under controlled hydrodynamic conditions is described. The apparatus incorporates an annular flow channel contained within a pressure vessel, which, in turn, is located in a single liquid phase once-through/recirculating high-pressure/high-temperature loop. Facilities are also included for electrochemical control of the test specimen. The mass transfer characteristics of the flow channel have been calibrated over the temperature range of 25 to 250 C by determining limiting currents for the oxidation of dissolved hydrogen in 0.1 M NaOH solution on platinized Alloy 600 as a function of rotation velocity of the flow-activating impeller. By assuming that previously established mass transfer correlations for annular systems hold over the entire temperature range and that the temperature dependence arises from the kinematic viscosity and hydrogen diffusivity, equivalent linear flow velocities have been calculated. At temperatures below 50 C, both the laminar and the turbulent flow regimes are accessible, but at higher temperatures, only turbulent flow was obtained.