Studies of small particle suspensions for L.M.F.R. Part I - fluid flow with suspensions simulating the U-Na systems

Abstract

Velocities of 2.5 to 2.9 feet per second (76 to 88 centimeters per second), are needed to prevent settling of tungsten powder in a 1-in i.d. horizontal pipe from aqueous suspensions containing 6.1 to 7.0 percent by weight of tungsten. In one instance a narrow moving bed was observed at a velocity of 3.8 feet per second for a suspension containing 5.0 percent of tungsten but the formation of a moving bed as not reproducible. Settling has been observed at Reynolds numbers as high as 36,300. The equation of Dallavale, (4), (5) suitably modified predicts settling velocities in a horizontal pipe of the same order as those found experimentally for dense solid, micron-sized particles suspension. For fully suspended flow, the friction factors lie approximately 10 percent above the smooth tube, normal liquid curve. It was not found necessary to consider non-Newtonian relationships to correlate the pressure drop data. At mean Reynolds numbers above approximately 3500 "streamlines" ha been observed in the lower half of the pipe for fully suspended flow. This phenomena is discussed but a full quantitative theoretical explanation is needed toothier with further experimental work.