SynopsisMeasurements were made of the total holdup, gas pressure drop and flooding velocities for flow through packed beds at low superficial velocities of liquid for various degrees of wetting between the liquids and solids.Correlations for both static and dynamic holdup, and a flooding diagram which is valid for non-wetting as well as wetting flow, were obtained.An instability of the bed, in which a transition from a stable to a fluidiced bed occurred, was observed before the onset of flooding in some experiments. A diagram was developed to differentiate f luidisation from hooding in relation to the flow conditions. The diagram indicates that, in blast , furnaces, fluidisation of the coke bed is likely to start before the onset of flooding by the slag. The abnormal flow phenomena which could occur in the furnace are discussed in terms of the fluidisation of the coke bed in the dropping zone.

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SynopsisWustite micropellets (Feo .s4iO) were isothermally reduced at 900N 1 100 °C with H2, CO and their mixtures. The e ffect of reducing gas composition and the total gas pressure on the rate of reduction was investigated. The kinetics and mechanisms of reduction deduced from the microscopic examination, surface area measurements and carbon analysis were found to depend mainly on the reducing gas composition. The highest rate of reduction was obtained in H2 while the slowest was in CO. The reduction with H9-CO mixtures was not additive.

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