Paper coater blowoff apparatus

Claim 2

The construction defined in claim 1 in which the collector chamber intermediate wall is flared and the collector chamber rear wall means is angular, and said flared and angular intermediate and rear walls converge to form a connected channel bottom wall forming a sump located within the suction chamber; and in which an upwardly convex curved wall projects from said flared wall into the collector chamber forming a vortex suppressor baffle within the collector chamber.

Claim 3

The construction defined in claim 1 in which an adjustable V-shaped member forms the common opening defining edge of the common suction and collector chamber rear wall means, and in which said V-shaped member has a flange projecting downwardly into the collector chamber forming a vortex suppressor baffle.

Claim 4

The construction defined in claim 1 in which the collector chamber intermediate wall is upwardly flared, in which the rear wall means is angular, in which the rear wall means terminates at the common opening defining edge, and in which the intermediate flared wall terminates in an upwardly inwardly curved opening defining edge.

Claim 5

The construction defined in claim 1 in which the spoiler blade means includes a blade having a top corner and having its flat surface extending at an angle toward the air knife acute with respect to a radial plane passing through the axis of the backup roll means and through said top corner.

Claim 6

The construction defined in claim 1 in which the spoiler blade means includes a blade having a tip corner, the blade having its flat blocking surface extending from said top corner and facing toward the air knife, and the blade having a curved upper edge extending from said top corner away from the air knife adjacent to but spaced from the traveling web, whereby a portion of the air and mist hugging the web and passing through the space between the spoiler blade and web hugs the curved spoiler blade edge beyond the flat blade surface and is directed into the collector chamber.

Claim 7

The construction defined in claim 1 in which the spoiler blade means includes a plurality of spoiler blades each having flat surfaces facing toward the air knife blocking flow of air and entrained mist discharged from the air knife means and hugging the coating surface of the traveling web, in which each spoiler blade has a surface opposite its flat surface, and in which said blades dirEct air and mist hugging the web into the collector chamber along their flat and opposite surfaces.

Claim 8

The construction defined in claim 1 including a mist separator, means connecting the mist separator with the suction chamber passage, and the suction means being connected with the mist separator to draw air and entrained mist from the blowoff box suction chamber through the suction chamber passage into the mist separator and to discharge air from the mist separator to the atmosphere.

Claim 9

The construction defined in claim 1 including coating material supply tank means, and conduit means connecting the collector chamber and supply tank means, whereby coating material liquid discharged into and collected in the collector chamber may be recycled to the supply tank.

Claim 10

The construction defined in claim 1 in which the suction chamber walls are formed of separable upper and lower sections, in which the upper section contains the rear wall means and the front and intermediate collector and suction chamber walls, and in which mounting means is provided for supporting and moving the upper and lower sections toward and away from the backup roll means, whereby said upper section may be detached from the lower section and moved out of normal operating position for access to the interior of said upper section.

Claim 11

The construction defined in claim 1 in which mounting means supports the blowoff box suction and collector chamber walls for movement toward and away from the backup roll means, and in which means is provided for moving said blowoff box walls toward and away from the backup roll means.

Claim 12

The construction defined in claim 1 in which vortex suppressor baffle means are mounted within the collector chamber extending parallel with the axis of the backup roll means, and in which said vortex suppressor baffle means are removably mounted within said collector chamber.

Claim 13

The construction defined in claim 1 in which the air knife means is adjustably mounted to vary its angle of impingement, in which vortex suppressor baffle means extends parallel with the axis of the backup roll means within the collector chamber and below the air knife means, and in which said baffle means is adjustable to coordinate its operation with adjustment of the air knife means.

Claim 14

In a coating apparatus blowoff box construction in which a web traveling along backup means and having a coating applied to one surface moves past air knife means directing in air jet at an angle against the coated web surface; the combination of blowoff box means including rear wall means, and front and end walls forming a suction chamber; walls including an intermediate wall forming a smaller coating material collector chamber within the suction chamber; the collector chamber walls having portions defining a top opening; the suction chamber front and rear wall means having inner edges, the suction chamber end walls having shaped upper edges matching the contour of the backup means, and said upper edges defining a suction chamber top opening at a location spaced above the collector chamber top opening and spaced below a coated web traveling along such backup means; the suction chamber rear wall means being in common the rear wall means of the collector chamber; the suction chamber opening edge at the top of the rear wall means defining in common a portion of the collector chamber opening and being located adjacent and below the air knife means; the intermediate wall having an upper edge defining another portion of the collector chamber opening, and said upper intermediate wall edge being spaced from and substantially close to the front suction chamber wall upper edge defining an opening to a suction chamber passage formed between said front and intermediate walls; suction means for the blowoff box means communicating with said suction chamber passage; spoiler blade means mounted within the blowoff box means extending parallel with the backup means and spaced a fixed distance away from the backup means and Extending transversely of the suction and collector chamber openings and into said suction and collector chambers between said intermediate walls and rear wall means; said spoiler blade means having a flat surface blocking the flow of a substantial portion of air-knife-discharged air which hugs the coated surface of the traveling web passing along said backup means and the mist formed by the air-knife-discharged air entrained by said coated-surface-hugging air, and directing said blocked air and entrained mist into said collector chamber; said spoiler blade means including a first blade having front and rear surfaced and a shaped edges between said front and rear surfaces, the front spoiler blade surface being the flat blocking surface and intersecting the shaped edge at a sharp corner, said shaped edge extending from said sharp corner parallel to tangency with the backup means, and said shaped edge then curving rearwardly downwardly to said rear blade surface.