A Method of Testing the Pour Point of Petroleum Products on a Refrigerated Sloping Surface

The method of testing pour points of pure substances and multicomponent hydrocarbon mixtures basing on the analyses of the path lengths of passing of equal volumes of substances along the tracking grooves on the refrigerated sloping metallic panel has been presented. Repeatability of the method makes up +/- 0.3 degrees C, which surpasses the repeatability of testing pour points by the known international standards (ASTM D5853-95, ASTM D97-09, ISO 3016, GOST 20287-91) 57 times. Operability of the method has been shown on the example of testing pour points of hexadecane, octadecane, and paraffinic oil. It has been established that experimental curve plotted in coordinates (length of sample passing path - temperature), can be presented by the sum of two terms, the first of which is described by hyperbola with asymptote at temperature, equal to the pour point of the sample, which actually corresponds to the flow regime, and the second term is described by the parabola of variable exponent and the contribution to drop rolling regime. Drop rolling has a greater contribution into the experimental curve with the increase of the panel slope angle, and with the greater difference between the temperature of the panel and the pour point of the sample.