In this study we experimentally investigated powder conveyance in a horizontal rectangular channel using fluidizing air. The conveying system consisted of a powder discharge vessel and a horizontal rectangular channel at the side of the vessel. The air velocities at the bottom of the vessel and the horizontal channel were changed experimentally. The powder was glass beads that are Geldart A particles, with a mean diameter of 53 pm, a particle density of 2523 kg/m(3) and a minimum fluidizing velocity of 4.329 mm/s. We measured the mass of the transported powder, the bed height of the powder in the vessel, the air pressures at the bottom of the vessel and the horizontal channel, and the flow pattern during powder conveying. Sufficient powder conveying could not be obtained when air was not supplied to the bottom of the vessel. On the other hand, the powder could be transported smoothly when air was supplied to the bottom of the vessel and the air velocity at the bottom of the horizontal channel exceeded the minimum fluidizing velocity. In this case, the powder was discharged smoothly from the vessel to the horizontal channel, and then the powder flowed easily toward the exit of the horizontal channel. The mass flow rate of the powder was in proportion to the falling velocity of the powder in the vessel, where that velocity was related to the discharge of the powder from the vessel. Therefore, it is found that the discharge of the powder from the vessel had significant effect on the horizontal conveying of fluidized powder in this system. (C) 2011 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.