Studies of small particle suspensions for L.M.F.R. Part IV concentration gradients in flowing suspensions

Abstract

A radiometric method and the apparatus used to measure concentration gradients in flowing suspension are described. Both iridium 192 and thulium 170 sources have been used to measure gradients. Traverses of both a horizontal and a vertical pipe, in which a tungsten-water suspension was flowing, have been made. Plots are given for various velocities of the concentration distribution in percent tungsten by weight across the pipe at right angles to the direction of flow. Very turbulent conditions, with velocities in excess of 13.4 feet per second (Re > 161,000) in a 1-in, square pipe, are needed before uniform suspension would be achieved. At 13.4 feet per second, the difference in concentration from top to bottom concentration. Much larger concentration gradients exist at lower velocities. In vertical flow no measurable concentration gradients exist for mean velocities of 2.6 to 6.3 feet per second, (Reynolds number 29,000 to 74,000) in a 1-in square pipe. Striations noticed in previous work near the settling point were again observed in this work.