Automatic spray cleaning apparatus and method

A cleaning method for removing material coated on the surfaces of a container comprising the steps of:

• forming a stream of cleaning liquid;
• directing the liquid stream at said surfaces so that the longitudinal axis of said stream forms an acute angle with said surface;
• and
• scanning said stream over said surface by moving said stream about a cleaning axis and longitudinally along such axis with a support means while maintaining said angle substantially constant over a given surface area during scanning at a given longitudinal position on said cleaning axis and while maintaining the spacing distance along the stream axis between the source of said liquid stream and the container surface substantially constant during said scanning at said given longitudinal position, without contacting said surface with said support means.

Cleaning apparatus for cleaning the surfaces of container tanks by spraying cleaning liquid at said surfaces, in which the improvement comprises:

• sprayer means for spraying said cleaning liquid under high pressure through a plurality of nozzles which each emit at least two streams of said liquid;
• support means for supporting said nozzles on support arms extending radially outward from a common support shaft which is supported to prevent nonaxial pivoting movement of said shaft so that the nozzles of each pair are space symmetrically about the axis of said common shaft;
• and
• means for balancing the reactive forces applied to said common shaft and to said inserted support arms by the liquid streams emitted from said nozzles so that substantially no total bending force is exerted on said common shaft or said support arms.

Automatic cleaning apparatus for removing material coated on the inner surfaces of containers by spraying cleaning liquid at said surfaces in which the improvement comprises:

• sprayer means for spraying said cleaning liquid under high pressure at cylindrical inner surfaces of said containers and including stream forming means for forming at least one stream of said liquid having a longitudinal axis;
• automatic drive means for moving said stream forming means over the container surfaces along a predetermined path to scan said container surfaces with said liquid stream, said drive means moving said stream forming means rotationally about a cleaning axis and longitudinally along said cleaning axis during the scanning;
• support means coupled to said drive means for supporting said sprayer means during said scanning, including first support means for causing the liquid stream to strike cylindrical container surfaces at an acute angle between said stream axis and the surface impinged thereby and for automatically maintaining said acute angle substantially constant over given surface areas of said cylindrical container surfaces during scanning as said stream forming means rotates about the cleaning axis at a given longitudinal position on said axis, and second support means for automatically maintaining the spacing distance along the stream axis between said stream forming means and the container surfaces substantially constant during said scanning at said given longitudinal position;
• and
• means for maintaining the pressure of said liquid stream substantially constant at said cylindrical container surfaces.