POWDER SUPPLY DEVICE

PURPOSE:To provide a powder supply device which can quantitatively supply a tracer powder used in measuring flow velocity of a fluid such as gas or liquefied gas into the fluid to be measured. CONSTITUTION:A disc 12 is provided inside a device body, a circumferential groove 13 is provided on the upper face of the disc 12, and a powder supply pipe 15 is provided piercing a casing of the device body and in capable of communicating inside to outside. And a nozzle plate body 17 having a powder communicating hole 20 piercing in the thickness direction is mounted at an end 15a in the inward side of the powder supply pipe 15 so that the powder supply device continuously supplies a powder F in the circumferential groove 13 carried continuously by rotation of the disc 12 to outside the device body. Also, in the neighborhood of the powder communicating hole 20 of the nozzle plate body 17, an air bypass passage 22 is provided piercing in the thickness direction with its lower opening 22b exposed above the circumferential groove 13.