Abstract: An apparatus for the deburring or coating removal of workpieces which are subjected to direct heat exchange with a low temperature coolant, e.g. liquid nitrogen, has a transport path extending around a sling wheel to which a granular path medium is supplied via a hollow shaft which is cantilever journaled externally of the treatment chamber. The blast medium is fed to the sling wheel via a nonrotatable tube extending through the hollow shaft so that centrifugal force does not cause free flow media to adhere to the inner walls of the shaft and impede delivery to the sling wheel.