Liquid metal irrigation of a packed bed

Abstract Liquid hold-up and gas phase pressure drop data are reported for mercury irrigation of a packed bed of 1 4 in. steel raschig rings with countercurrent flow of hydrogen and nitrogen. The static hold-up of mercury was found to decrease slightly with increasing liquid rates. This effect, not observed in aqueous or organic liquid irrigations, is attributed to an increased mobility of the liquid in the bed because of the greater energy associated with the flow of dense media such as a liquid metal. When nitrogen was the gas phase, the static hold-ups, dynamic hold-ups and irrigated liquid specific surfaces are all larger than those observed under comparable conditions with hydrogen as the gas phase. This is considered to be due to the greater interfacial tension of mercury and nitrogen. An empirical correlation is developed between the liquid hold-up, gas phase pressure drop, gas mass flow rate and gas density. It is suggested that this type of correlation would be of value for estimating the hold-up of molten metal or slag in high temperature systems, where direct measurement would be difficult, but where a room temperature analogue could be readily constructed.