The conveying characteristics of powder material transport are investigated for a pilot plant pneumatic conveyor. The experimental system is a closed loop dense phase pneumatic conveying system incorporating a 'Turbuflow' system. Powder materials like cement, flyash, pulverized coal and rawmeal have been conveyed, and their suitability to be conveyed in dense phase are investigated. Useful conclusions are drawn for the design and layout of the dense phase pneumatic conveying system. © 1993, Society of Powder Technology Japan. All rights reserved.