INSTRUMENT FOR MEASURING MASS FLOW RATE OF POWDER, AND ELECTROSTATIC POWDER COATING APPARATUS UTILIZING THE SAME

摘要

A miniaturized, inexpensive instrument for measuring the mass flow rate of powder, which is capable of directly outputting the mass flow rate of powder and whose characteristics are not influenced by the kind and physical properties of the powder. The instrument can be easily manufactured, installed, operated, maintained, and color change can be easily done. A constant powder feeder, which is constructed based on this instrument and an electrostatic powder coating system utilizing this feeder has a high performance and a high operational efficiency. A measuring gas with a regulated flow rate is turned into a thin-layer of high-speed gas jets by a dispersion means, thereby powder is cross-dispersed and introduced into a measuring tube, the pressure difference generated therein is measured, and a feeding means is subject to feedback control so that the output of the pressure difference coincides with a set value.