The lomps of sand are placed inside the eylinderical cage which is supported by a number of coil springs. Two vibrating motors move the whole cage up and down disgonally and this moves the sand around. The rubbing action of the lumps and the impingement of the lumps against the inside wall of the cage break the lumps into individual grains which drop out of the cage through the shits.
Loose brick bits, small lumps and scrap metals remain in the cage. and after the completion of the work they will be taken out by vibration through the side door.