No abstract

The velocity of glass beads entrained with air flow in a horizontal square duct was measured in a range of pressures: 760-1 mmHg,ua: 10, 18 m/sec, dv\ 81.5-184microns, D: 2.45 cm. It is pointed out that with respect to the flow regions in duct and around particle the present experimental conditions are considerably different from those in previous works at atmospheric pressure. Data obtained under reduced pressure are correlated within ±30 %by the following equation, which includes the Cunninghamcorrection coefficient Cm.(ua -up)/ua = 1.22Cmdpu0aA j/a=air velocity [cm/sec], up -particle velocity [cm/sec], dp =particle diameter [cm].