Phupongskorn T., Rirksomboon T., Lister D., Steward F., 2012, Determination of Impinging Jet Correlation and Dissolution of Materials, Chemical Engineering Transactions, 29, 967-972.
The rate constant for the dissolution in water of a range of materials may be important for designing process equipment or determining the mechanisms of chemical reactions. A jet-impingement apparatus has been used to study dissolution rates by directing a jet of water onto a pellet surface of the material of interest at high velocity to ensure that dissolution is controlling at the given conditions. The apparatus has been used to measure the dissolution rate constant of magnetite under the conditions of power system coolants – often a controlling parameter in steel corrosion. For unequivocal measurements of the dissolution rate constant, the mass transfer characteristics of the apparatus need to be known in order to extrapolate mass transfer coefficients to the conditions of interest. Experiments have been performed using pellets of cast plaster of Paris of different purities and single crystals of the same material (gypsum – CaSO4·2H2O), as well as pellets of trans-cinnamic acid, potassium bitartrate and aspartic acid. The dissolution rate constants for single crystal gypsum and aspartic acid were determined and found to be in good agreement with literature values and the commercial plaster result led to a mass-transfer correlation for the jet-impinging apparatus in reasonable agreement with a published correlation. However, the commercial plaster tended to have a higher solubility than pure plaster or gypsum crystals; its dissolution rates were higher than those of the other materials studied, which were in the same range.
