An impeller for a centrifugal blast wheel machine includes a hub provided at one end of the impeller, with the hub being configured to be coupled to the motor. The hub further includes a ring provided at an opposite end of the hub, with the ring defining a media inlet to receive blast media. The impeller further includes a plurality of cylindrical vanes positioned between the hub and the ring. The plurality of cylindrical vanes is spaced from one another on peripheries of the hub and the ring. The plurality of cylindrical vanes defines a plurality of impeller media outlets constructed and arranged to allow egress of blast media upon rotation of the impeller.

The centrifugal projector (1) of the present invention has: a side plate (11), a plurality of blades (3) attached to the side plate (11), a control cage (41-45) disposed on a radial inner side of the side plate for releasing the projection material between blades from an opening portion (41a-45e), a distributor (22), disposed on a radial inner side of the control cage, for mixing and supplying the projection material to the control cage, and a rotary shaft (14) for rotating the side plate, blades and distributor; wherein the blades are formed to be pitched so that a radial outer side (3c) thereof is positioned to a rear in the rotational direction (R1) compared to a radial inner side (3b) thereof; the control cage (41-45) has a plurality of opening windows (41a-45e), or a single opening window in which a portion or all of a plurality of opening windows are respectively overlapped and integrated into a single piece.

An abrasive grain jet grinding device having a belt partially wrapped around an impeller with blades between a shaft-side disc and an open disc and an open peripheral surface between the blades, a nozzle tangential to the disk at the point of separation between the belt and the peripheral surface, wherein the blades held between the shaft-side disc and the open disc are formed from thin plates to finely partition the circumference of the discs, are inclined forward in the direction of rotation of the discs, are provided densely so that multiple adjacent blades overlap each other, and are set with narrow gaps between the blades to form a large number of storage chambers for the abrasive grains.