The hydrodynamics of two (water-air, water-solids) and three (water-air-solids) phase fluidized beds have been studied in a large two-dimensional column. Two solids were used, namely 6 mm glass beads and 2.6 mm irregular gravel.

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Heat transfer from a vertical grid jet within a 2 ft diameter and 4 ft deep fluidized bed of cracking catalyst was studied. The test nozzle diameter was varied from ¼ to 1 in. and the nozzle velocity from 50 to 250 ft /sec which is within the range of industrial practice. The axial temperature data have been related to a Froude, a Reynolds and a Nozzle number: In (δT/δTo) = –58.1 Fr−0.562 No1.08 Re−0.112 A simple jet quenching model yielded heat transfer coefficients between the fluid bed and grid jet which ranged from 300 to 1200 Btu/ft2 hr.o F.

Four experimental aspects of momentum dissipation of grid jets in a gas fluidized bed of cracking catalyst are reported. First, an investigation was made into the radial distribution of axial momentum for air jets issuing from vertical long nozzles into a minimally fluidized bed. The theory of Abramovich was compared with these experimental results. Second, data on the distribution of axial momentum along the axis for vertical air jets issuing from single and multi‐hole grids were compared with previous work. Third, the axial dissipation of vertical air jets loaded with fluid cracking catalyst issuing into air and also into a fluid bed was studied. Finally, the shape of the boundary of a jet dissipating into a fluid bed was compared to that given by theory.

Entrainment from a gas fluidized bed of cracking catalyst in a 2‐ft diameter column equipped with continuous solids recycle has been studied. Radial profiles of entrainment rate and mean particle size were relatively flat. The entrainment rate decreased rapidly with increasing height above the bed and with decreasing fluidizing velocity. The existence of a transport disengaging height above which the entrainment rate and mean particle size become essentially constant was confirmed experimentally. This may be taken as the height above the bed surface at which the inverse Froude number becomes equal to 1000.