Vibratory finisher with blasting nozzle

A process for abrading flowable bulk parts, comprising:

• providing a vibratory treating device defining therein a horizontally elongated, upwardly opening treating channel having a width which is small relative to the channel length;
• supplying a flowable bulk mass containing a large quantity of bulk parts into said channel at a supply location so as to fill the channel to a depth less than the maximum channel depth;
• providing said flowing bulk mass with bulk insert tumbling elements mixed with said bulk parts to provide for carrying and spacing of the bulk parts as they are tumbled along the channel, the inert tumbling elements having a shape which is different from the shape of the bulk parts;
• vibrating the treating device so that the bulk mass flows lengthwise of the channel while undergoing a gentle continuous movement along a generally helical flow path which extends lengthwise of the channel away from the supply location and has numerous closely-adjacent transverse convolutions so that the individual bulk parts are gently rotatably tumbled in a generally transverse circular path and are simultaneously advanced lengthwise of the channel;
• providing a first discharge nozzle having a discharge orifice positioned closely adjacent and above and downwardly directed toward the helically flowing mass within the interior of said treating channel at a location between said supply location and a discharge location for said parts;
• discharging from the orifice of said discharge nozzle a downwardly directed abrasive spray defined by high-velocity air containing entrained abrasive particles to define a first spray zone which penetrates into the helically flowing mass over a substantial width and depth thereof and which contacts the helically flowing mass over a lengthwise extent which at least equals the forward advance per convolution thereof to effect abrading of the parts as they move through the spray zone due to the gentle rotatable tumbling of the parts transversely of the channel and the simultaneous lengthwise advancement thereof;
• providing a second discharge nozzle having a discharge opening position closely adjacent and above and directed downwardly toward the helically flowing mass within the interior of said treating channel at a location which is spaced downstream from said first discharge nozzle in a direction of flow of the flowing mass along the channel;
• discharging from the orifice of said second discharge nozzle into the continuous tumbling mass an abrasive spray defined by a high-velocity carrier fluid having entrained abrasive particles to define a second spray zone which penetrates into said helically flowing mass downstream from said first spray zone to effect further treating of the parts as they move through the second spray zone due to the vibratory helical tumbling movement thereof, the abrasive spray discharged from said second discharge nozzle having physical properties which are different from the abrasive spray discharged from said first discharge nozzle;
• the helical vibratory movement of the tumbling bulk mass along the channel causing and allowing the orientation of the individual bulk parts within the helically flowing mass to constantly change as the parts slowly move through the first and second spray zones so that different surfaces and edges of the parts are subjected to the high-velocity abrasive sprays which, in combination with the gentle tumbling contact of the parts with one another, effect surface treating of the parts;
• discharging the flowable bulk mass from the treating channel at said discharge location which is disposed downstream from said second spray zone;
• and
• continuing the vibration of the treating device to continue the gentle helical flow of the bulk mass from the supply location into, through and then downstream away from the first spray zone and thence into, through and downstream away from said second spray zone and thence downstream for discharge of the bulk mass at said discharge location so that the bulk mass is subjected to a first-in first-out treating operation.