lagging of the auger and pipe elements and hose the particles reaching the surface will be sufficiently hard and sharp and particularly by virtue of the air pressure will have sufficient kinetic energy as to dislodge contaminants from the surface in essentially the same way as does sand in a conventional blast cleaning operation unlike sand however the ice particles will melt sooner or later so that the removal of the dislodged contaminants becomes relatively easily effected by filtration from the water it will be understood from the description of the charging chamber 2 that as each compartment defined by an adjacent pair of blades 7 moves away from the inlet opening 8 another such compartment takes its place so that while ever the rotor is turning and ice is being fed to the chute 3 a continuous supply of ice will be presented to the auger if in spite of the control of the speed of both the auger and of the rotor ice is presented to the auger at a faster rate than it can advance towards the hose 1 so that a compartment still contains ice after it has passed the opening 9 the remaining ice is discharged from the opening 10 into chute 22 the material discharged from the chute 22 is conveniently returned to the ice making machine again if ice is produced by the.