Effect of Nozzle Depth on Pneumatic Conveying Characteristics of Suction Nozzle with Injection Pipe

In the vacuum system of pneumatic transport, the authors have proposed, that a suction nozzle equipped with an injection pipe at the center, would provide a highly-dense therefore a highly-efficient method of transporting a powder. In this paper, we examine the effect of nozzle length, the inserted depth of the suction nozzle into the powder bed. The resulting data show that the nozzle performance improved in a range of lower nozzle depths, but saturated in a range of higher nozzle depths with no insertion length of injection pipe. The powder behavior near the suction nozzle at different nozzle depths was observed with powder flow visualization.