Apparatus and method for cleaning and recovering paint in painting plants

A paint recovery and cleaning trolley for an apparatus for applying paint provided with a conveyor belt for conveying pieces to be painted, the conveyor belt having an upper outward section and a lower return section, the trolley including:

• a paint recovery subunit, in its turn including:
• a reverse roller in contact with the lower return section of said conveyor belt, which in use recovers paint from the conveyor belt,
• a doctor blade tangentially placed with respect to said reverse roller for all its length, to allow the accumulation of a solvent and wetting said reverse roller;
• a doctor blade scraping the reverse roller so recovering paint;
• a doctor blade scraping the lower return section of said conveyor belt,
• at least one nozzle for supplying a solvent compatible with the paint in use,
• a collecting hopper collecting said solvent, placed under said reverse roller,
• a paint collecting reservoir,
• a cleaning subunit, in its turn including:
• a reverse roller in contact with the lower return section of the conveyor belt, which in use recovers paint from the conveyor belt,
• a doctor blade tangentially placed with respect to said reverse roller of the cleaning subunit for all its length to allow the accumulation of a solvent and wetting said reverse roller,
• a doctor blade scraping the lower return section of said conveyor belt,
• at least a nozzle for supplying a solvent,
• a collecting hopper collecting said solvent, placed under said reverse roller of the Cleaning subunit,
• a solvent collecting reservoir,
• wherein in each subunit the respective components reverse roller, doctor blades and return section of the conveyor belt form a closed chamber having the shape of a triangular prism of which said components represent the rectangular faces, said chamber containing said solvent, which drips from the triangular faces of said chamber into the respective collecting hopper;
• wherein there are provided three positions of the trolley with respect to the apparatus for applying paint, said three positions including
• an operative position, in which said trolley is totally inserted under said conveyor belt, and the paint recovery subunit and the cleaning subunit are lifted so that they are in contact with the lower return section of said conveyor belt;
• an inactive inserted position, in which said trolley is totally inserted under said conveyor belt, but the paint recovery subunit and cleaning subunit are lowered so that they are not in contact with the lower return section of said conveyor belt;
• a lateral extracted position, in which said trolley is totally extracted from the apparatus for applying paint;
• wherein a shift from the operative position to the inactive inserted position is performed owing to at least one tongue provided in the sides of said trolley, which couple with a plate moved by a pneumatic cylinder of the apparatus for applying paint allows the lifting of said trolley, said pneumatic cylinder being integral with a frame of the apparatus for applying paint.

A paint recovery and cleaning trolley for an apparatus for applying paint provided with a conveyor belt for conveying pieces to be painted, said conveyor belt having an upper outward section and a lower return section, the trolley including:

• a paint recovery subunit, in its turn including:
• a reverse roller in contact with the lower return section of said conveyor belt, which in use recovers paint from the conveyor belt,
• a doctor blade tangentially placed with respect to said reverse roller for all its length, to allow the accumulation of a solvent and wetting said reverse roller;
• a doctor blade scraping the reverse roller so recovering paint;
• a doctor blade scraping the lower return section of said conveyor belt,
• at least one nozzle for supplying a solvent compatible with the paint in use,
• a collecting hopper collecting said solvent, placed under said reverse roller,
• a paint collecting reservoir,
• a cleaning subunit, in its turn including:
• a reverse roller in contact with the lower return section of the conveyor belt, which in use recovers paint from the conveyor belt,
• a doctor blade tangentially placed with respect to said reverse roller of the cleaning subunit for all its length to allow the accumulation of a solvent and wetting said reverse roller,
• a doctor blade scraping the lower return section of said conveyor belt,
• at least a nozzle for supplying a solvent,
• a collecting hopper collecting said solvent, placed under said reverse roller of the cleaning subunit,
• a solvent collecting reservoir,
• wherein in each subunit the respective components reverse roller, doctor blades and return section of the conveyor belt form a closed chamber having the shape of a triangular prism, of which said components represent the rectangular faces, said chamber containing said solvent, which drips from the triangular faces of said chamber into the respective collecting hopper
• wherein in said paint recovery subunit and in the cleaning subunit said solvent follows two distinct paths which are distinct up to their end, in that in the paint recovery subunit the solvent which accumulated on the reverse roller and collected in its respective hopper is channelled to a solvent recovery reservoir through a collector and a funnel, said solvent being recirculated from said solvent reservoir to its respective nozzle through a pump;
• while in the cleaning subunit the solvent which accumulated on the reverse roller and collected in its respective hopper is channelled to a solvent recovery reservoir through a collector and a funnel;
• said solvent being recirculated from said solvent reservoir to its respective nozzle through a pump.