Abstract: A powder feed device for supplying a powder dispensing apparatus such as a powder spray gun of an electrostatic powder deposition system. Entrained powder is extracted from a fluidization tank and transported through a half-inch diameter tube or hose to the dispensing apparatus. To prevent clumps of powder and/or powder adhering to the walls of the tube or hose while permitting reduced air flow speed of about 2 to 3 m/s an electric field is provided in the tube or hose and applied by an outer conductor extending around the tube or hose and an inner wire conductor inside the tube or hose extending in the direction of the flow of entrained powder, which conductors are connected across an AC voltage source. The electric field may operate constantly or intermittently.

Abstract: Transmission of a slurry along a pipeline by ultrasonic sound waves introduced at an angle to the direction of flow of the slurry particles to intersect the moving particles with a forward and lifting component. Ultrasonic generators or transducers are placed along the bottom of a pipeline at preselected angles relative to the pipeline and flow of material therealong. The ultrasonic waves are in the nature of mechanical waves and may be of a given frequency for specific types of solids. The slurry for which this apparatus is particularly adapted is a slurry of coal particles in the range of approximately 30 to 70% solids by weight with a general spatial concentration of approximately 50%. The mechanical ultrasonic waves propagating in the slurry, which is an elastic body, lift the particles by the angular components of the waves and propel the particles along the pipeline by the horizontal components of the ultrasonic waves.