Patent ID: 7943012

Claim:
A device for protecting spraying equipment in a paper or board machine, the spraying equipment being mounted adjacent to a first moving surface of the machine for applying a treatment medium thereon within a machine-wide application zone having opposing upstream and downstream sides, said device comprising: a machine-wide protecting cover defining a single-chamber internal space configured to enclose the spraying equipment and defining an opening directed toward the first moving surface, the opening extending over the application zone, said protecting cover comprising: first and second machine-wide wall elements extending transversely to the machine direction along the upstream and downstream sides of the application zone, respectively, each of the first and second wall elements being spaced apart from the first moving surface so as to define respective machine-wide first and second gaps therebetween; a sealing arrangement comprising at least one machine-wide mechanical sealing device, the sealing device being: operably engaged with the first and second gaps; configured with respect to the first and second gaps to selectively restrict passage of at least a portion of a boundary layer air flow created adjacent the first moving surface and contaminants contained therein through at least one of the first and second gaps and into the internal space; and replaceable with a replacement sealing device, the replacement sealing device being configured to one of maintain, decrease and increase a size of at least one of the first and second gaps; a capture air supply system comprising the at least one machine-wide mechanical sealing device operably engaged with the first gap and configured to supply to the internal space at least a portion of a radial inner layer of the boundary layer air flow as capture air for capturing contaminants contained within the internal space; and an evacuating system operably engaged with the internal space and configured to selectively and continuously evacuate the capture air with contaminants therefrom.