US Patent 7435315 Arrangement for stabilizing a web

The object of the invention is an arrangement for stabilizing a paper web (3) in a paper machine, which arrangement comprises at least three cylinders (4, 5, 6) which have been arranged so that a pocket space is formed between them, a blow box (7) arranged in the pocket space, which blow box has a blow nozzle (12), in which a nozzle slot (19) has been arranged, a separate wall (10), substantially in the direction of the blow box (7), which wall has a first edge and a second edge that are substantially parallel, which has been attached from its first edge to the blow box (7), whose height in the travelling direction of the paper web (3) is 25-300% of the height of the blow box (7) in the travelling direction of the paper web (3), in the second edge of which wall there has been arranged a boundary layer air doctor (15), which extends substantially unto the surface of the cylinder (4, 5, 6), and which wall (10) has been attached to the blow box (7) so that the blow box (7) and the wall (10) form a space in the area between the opening nip (8) and the closing nip (9) following it, into which space an underpressure can be arranged in order to support the paper web (3) towards the fabric (2) in the area between said nips (8, 9).