Method and apparatus for measuring powder flow rate

摘要

A powder flow rate is measured based on a simple construction so as to provide method and apparatus for measuring the powder flow rate for example of a powder coating material, requiring less maintenance cost and facilitating change of color of the coating material. In the method for measuring powder flow rate: a density rho 1 of the powder within a tank is measured; the powder is drawn out from the tank into a conveying tube; a detecting fluid is blown at a flow rate Qf into the conveying tube a density rho 2 of the powder in the conveying tube is measured; and a powder flow rate Fm is measured based on an equation of Fm=Qfx rho 1x rho 2/( rho 1- rho 2). The density rho 1 of the powder in the tank may be measured by providing a pair of pressure measuring devices at different heights within the tank. The density rho 2 of the powder in the conveying tube may be measured through a measurement of electrostatic capacity, light transmittance or ultrasonic wave transmittance in the conveying tube.