Apparatus for controlling electric charge on finely divided powder and finely divided spraying

摘要

An apparatus for controlling an amount of electric charge on a finely divided powder supplied into a powder transportation pipe in a substantially discrete particle state and transported therethrough in a stream of a compressed gas having a very small water content whose dew-point is 0° C. or less where electric charge is produced by friction on the powder by the collision thereof against the inner wall of the transportation pipe, controls the dew-point of the compressed gas, and the controls amount of frictional electric charge produced on the powder by uniformly spraying the powder onto a grounded sheet surface in a discrete particle state by use of a swinging nozzle.