Tool for excavating an object

A tool for excavating an object comprises a jetting system having a nozzle arranged to receive a fluid and abrasive particles via an abrasive particle inlet, and arranged to impinge the object to be excavated with a jetted stream of the fluid mixed with the abrasive particles, the tool further having a recirculation system arranged to recirculate at least some of the abrasive particles from a return stream, downstream of the impingement of the jetted stream with the object to be excavated, back to the jetting system via the abrasive particle inlet, the abrasive particle inlet having an entrance window in which a device in a path fluidly connecting the return stream with the entrance window keeps the abrasive particle inlet free from objects of the same size or larger than the size of the window while allowing passage of the abrasive particles.