Gas-particle two-phase jet flow from slot nozzle and micro-blasting process

Abstract

Recently micro-blasting process has been widely used to process brittle material, and at that time a conventional circular nozzle was commonly used. But, the cutting performance of the circular nozzle does not process a large area well so the use of a slot nozzle is considered. In this study, in order to improve the cutting performance of the micro-blasting nozzle, a new slot nozzle with a large aspect ratio is proposed and the flow characteristics and cutting performance are examined precisely by experimental and numerical analysis. Main results show that (1) setting the circular vane in the slot nozzle perpendicular to the stream can diffuse particle flow uniformly at the nozzle exit and then particle velocity distribution becomes uniform, (2) expanding the nozzle outlet at an angle, uniform air and particle velocity distributions at the nozzle exit can be obtained, (3) in spite of setting obstacles in the nozzle, a fine cutting efficiency is obtained compared to the conventional micro-blasting circular nozzle.