Wet blasting machines

A wet blast machine for cleaning or preparing surfaces of at least one product, said machine comprising:

• a treatment source for providing a treatment material, comprising a treatment pipe for providing the treatment material to a plurality of nozzles, the treatment pipe comprising a treatment bore, wherein each nozzle extends from the treatment pipe such that a nozzle inlet of each nozzle is in fluid communication with the treatment bore;
• a pressurized air source for pressurizing the treatment material;
• a plurality of pressurized air inlet pipes extending from the treatment pipe, each air inlet pipe comprising an air bore in fluid communication with the treatment bore and a respective one of the plurality of nozzles, for diverting a portion of the pressurized mixture of treatment material into the nozzle through the inlet of the nozzle, wherein each nozzle comprises:
• a central longitudinal axis;
• a plurality of internal diameters along the central longitudinal axis such that the nozzle has a non-uniform internal diameter along its longitudinal axis;
• the nozzle inlet for receiving the pressurised mixture of treatment material;
• an outlet for ejecting said pressurised mixture;
• and
• at least one hole in a wall of the nozzle, said at least one hole for feeding the one or more products into one of the plurality of nozzles at an angle relative to the central longitudinal axis of the nozzle such that the surfaces of the at least one product are exposed to the treatment material whilst within the respective nozzle, and wherein the at least one hole is in a portion of the nozzle such that the one or more products are exposed to the treatment material at a maximum flow velocity of the treatment material.