Study on atomic sodium release from pulverised coal particles in a pre-mixed natural gas flame
Atomic sodium release during coal combustion has been shown to be a significant factor in fouling and corrosion of heat transfer surfaces within industrial coal-fired boilers. Although there has been significant research into the final forms of sodium from combustion, information about the release of sodium is limited. An initial study of the release of atomic sodium from pulverised coal particles in a pre-mixed natural gas flame was conducted using planar laser induced fluorescence, PLIF. Measurements were made of the intensity of sodium fluorescence, coal particle velocities and gas phase temperature within the flame in a purpose-designed laminar flame facility that provides similar time-temperatures history to coal particles in their early stages of combustion in an industrial coal-fired boiler. The velocity of the coal particles was measured to be about 6.1 m/s using particle streak velocimetry obtained from the natural luminescence of the hot particles and a 2.25 ms gate of the CCD camera. Temperatures were measured using thermocouples, and the maximum measured temperature was ~1500 °C. Calibration of the sodium fluorescence was not undertaken, but useful information was obtained of the release rate of sodium atoms from combusting pulverised coal particles.
The fate of sodium during pulverized coal combustion
Abstract The distribution of sodium in the different sizes of fly ash produced during coal combustion provides useful insights into the vaporization and condensation mechanisms for sodium. For the residual fly ash, the departure of the concentration of sodium from an inverse square dependence on particle size can be used to infer the degree of sodium vaporization. For low-rank coals most of the sodium vaporizes at combustion temperatures
Rotating dialysis cell as in vitro release method for oily parenteral depot solutions.
The purpose of the study was to investigate an in vitro release method based on a rotating dialysis cell for parenteral oil depot formulations using different model conditions and test formulations. The total amount of drug released from the rotating dialysis cell was in accordance with the theoretical values calculated from the partition coefficients. The release rates were shown to depend on the total amount of drug available for the release process and to follow first order kinetics. The rotating dialysis cell has a potential as in vitro release method for characterization of oily depot formulations for parenteral administration.