To make it possible to continuously analyze particle size by removing representative partial stream while guaranteeing the isokinetic capturing conditions of a main stream in a pneumatic conveyance conduit loaded with particles.
The method for continuously collecting powder or dust-like sample from gas stream loaded with particles comprises the steps of removing sample main stream loaded with the particles in a pneumatic conveyance conduit 17, and sending it to a particle size measuring unit 10 via a capturing tube 9. To reduce the rotation, the main stream in the conduit 17 is passed through a venturi-like sectional converging unit 3 having 10 to 60% of the sectional area of the conduit 17. Then, the partial stream is captured in parallel with the flowing direction of the main stream at the downstream of the unit 3, and the sample is captured from one or more test tubes. With respect to the jet mill 14 where product to be comminuted and propulsion air are continuously introduced, the particle size distribution measured at the continuously captured sample stream is used as a control factor, and the factor of deciding the distribution of the mill 14 is regulated so that the distribution in the product stream remains constant.
MATEIASU BENTSU
IERUKU RAINAA SHIYUMITSUTSU
HAIKO HERORUTO
