Flow unit for measuring heats of mixing at subambient conditions Available to Purchase

A type of mixing flow unit for BT 2.15D SETARAM calorimeter was designed for measuring heats of mixing of two liquids or a gas and a liquid. A cooling system using a cryostat circulating a cooling agent (ethanol) through the instrument was proposed and tested for temperatures down to $−50°C$⁠. In addition, a special heat exchanger was constructed for cooling down fluids entering the calorimeter when experiments are performed at subambient temperatures. In comparison with cooling by liquid nitrogen, the operation is less expensive and no tedious manipulations with liquid nitrogen are needed. A procedure for measuring with the mixing unit was developed and the assembly was successfully tested in the temperature range from $−30to75°C$ and at pressures up to $14MPa$ using several binary systems (liquid-liquid) where reliable literature data were available. The proposed flow arrangement is much more efficient and convenient to use at subambient temperatures compared to conducting experiment in a batch mode, which is the approach still prevailing at these conditions.