Device in washing of a wire in a paper/board machine

Abstract: The invention concerns a device (10) in washing of a wire (H 1 ) in a paper/board machine, which device comprises, at one side (F 1 ) of the wire (H 1 ), a wash-nozzle pipe (11), by whose means the washing liquid is sprayed as a jet (S) onto the face (M 1 ) of the wire (H 1 ). In a way in itself known, at the opposite side (F 2 ) of the wire, the equipment comprises a suction device (12), through which the mist arising in the washing of the wire is absorbed out of connection with the device, and that, in the solution of equipment, directly alongside the suction device (12), at the same side (F 2 ) of the wire, there is a blow device (13), through which air is blown onto the face (M 2 ) of the wire (H 1 ) and through the wire.

Description: The invention concerns a device for removing the mist arising in high-pressure washing of a wire in a paper/board machine. From the applicant's s FI Patent 82,954 , a device is known for removing the mist arising in high-pressure washing of a wire. In the equipment, the washing mist is directed at the wire from one side of the wire, and the suction effect is applied to the mist arising in washing from the opposite side of the wire. Preferably, the suction duct of the suction device is placed as inclined in relation to the running direction of the wire so that the acute angle between the suction duct and the running direction of the wire is opened towards the running direction of the wire. In such a case, the mist can be guided accurately into the suction duct of the suction device. Moreover, in the solution of equipment, at the forward side of the suction duct in relation to the running direction of the wire, a separate rib is employed which can be positioned. By means of the rib, it is possible to regulate the guiding of the mist into the suction duct and, moreover, by its means, a detrimental effect of the boundary layer of humid air, carried on the face of the wire, upon the suction process is prevented. Moreover, from the applicant's s FI Utility Model Application U930584 of earlier date, such a solution of a device for removal of washing mist is known in which the rib that can be positioned has been replaced by a stationary, relatively wide ceramic or equivalent rib, which may reach contact with the wire. In such a case, the absorption of mist out of connection with the device is intensified further. In said solution, it is possible to use a plastic rib, which has been reinforced, for example, by means of wear-proof additive components. The rib may also be a ceramic one. As the wire may reach contact with the rib face in said embodiment, by means of the rib it is possible to deflect the wire, in which case the wire can be kept in contact with the rib also in such solutions of equipment in which it is necessary to be able to adjust the tension of the wire. In the present application, a further improvement is suggested for the solutions mentioned above. In the present application, it is suggested that, in addition to the washing device and the suction device, a device that blows drying air is employed after the suction device. In the present application, moreover, such a solution of equipment is suggested that the blowing of air that provides the drying, preferably an equipment for blowing of warm air, is placed at the same side of the wire at which the device for suction of washing mist is placed. Said arrangement of equipment is favourable from the point of view of the construction, because then the equipment for suction of the mist jet and the equipment for the supply of drying air can be constructed as a unified frame construction, which is provided with a connection for the moist air to be sucked off and an inlet connection for the air to be blown into connection with the wire as well as, moreover, an exhaust connection for the water gathered in the collecting trough. According to the present invention, the suction equipment preferably comprises two ribs, preferably made of ceramic ribs, placed at both sides of the suction duct; at the inlet side and at the outlet side (seen in the running direction of the wire). Further, the rib at the outlet side is fitted to form a blow gap, together with a third rib, which can be positioned, so as to blow drying air into connection with the wire. The equipment in accordance with the invention is mainly characterized in that, in a way in itself known, at the opposite side of the wire, the equipment comprises a suction device, through which the mist arising in the washing of the wire is absorbed out of connection with the device, and that, in the solution of equipment, directly alongside the suction device, at the same side of the wire, there is a blow device, through which air is blown onto the face of the wire and through the wire. The invention will be described in the following with reference to some preferred embodiments of the invention illustrated in the figures in the accompanying drawings, the invention being, however, not supposed to be confined to said embodiments alone. Figure 1 is a sectional view of an equipment in accordance with the invention. Figure 2A shows a displaceable third rib, which is connected with the mechanism of regulation of the air-blow nozzle gap. Figure 2B shows the construction of Fig. 2A as viewed in the direction of the arrow K 1 in Fig. 2A. Figure 2C illustrates the profiling of the supply of drying air across the machine width. Figure 3 is an axonometric view of an equipment in accordance with the invention. Figure 4 shows an embodiment in which a plate is used for guiding the jet/mist. As is shown in Fig. 1, the wire washing device 10 comprises, at one side F 1 of the wire, a wash-nozzle pipe 11, which sprays the high-pressure washing liquid and through whose nozzle openings the washing liquid is sprayed at a high pressure as a jet S onto the face M 1 of the wire H 1 . Further, the washing device 10 comprises a suction device 12 and a blow device 13, which have a common frame 14, at the opposite side F 2 of the wire H. The suction device 12 and the blow device 13 with their constructional parts, such as ribs 20a 1 ,20a 2 ,20a 3 , extend across the wire width. The suction device 12 comprises a suction duct 15, whose central axis X is placed at an oblique angle α in relation to the running direction L 1 of the wire H, said oblique acute angle opening in the running direction L 1 of the wire H 1 . A vacuum is applied to the suction chamber D 1 of the suction device 12, the mist jet arising in the wire washing being sucked through the suction duct 15 from the side F 2 of the wire into the suction duct 15 of the suction device 12 and further into the suction chamber D 1 . In the suction chamber D 1 , at least part of the water is separated into the collecting trough 17, from which it is passed through the drain duct 18 out of connection with the device. Part of the water that has been sucked is removed through the duct 16, and, in an embodiment of the invention, some of said removed portion of air can be passed through a separate cleaning stage and cleaning device into the blow device 13. The suction duct 15 comprises a straight duct portion 15a and, at its end, a curved duct portion 15b, which opens into the suction chamber D 1 . The equipment comprises three ribs 20a 1 ,20a 2 ,20a 3 in connection with the suction device 12 and the blow device 13. At both sides of the suction opening A 1 of the suction device 12, there are ribs; the rib 20a 1 at the inlet side in relation to the running direction L 1 of the wire, and at the opposite side of the opening A 1 , at the trailing side in relation to the running direction of the wire, there is the second rib 20a 2 . The ribs 20a 1 ,20a 2 are preferably ceramic, highly wear-resistant ribs. They can also be made of some other material, such as plastic. Each rib 20a 1 ,20a 2 and 20a 3 comprises a rather wide, about 20...60 mm wide face C 1 ,C 2 and C 3 , which may reach contact with the face of the wire H 1 . In the way shown in Fig. 1, moreover, the solution of equipment comprises a blow device 13 at the side of the suction device 12 at the side F 2 of the wire, blowing air, preferably very dry heated air, being produced out of the blow chamber D 2 of said blow device 13 into connection with the wire H 1 through the duct 19. The air is blown out of the chamber D 2 through the blow gap A 2 between the rib 20a 2 and the third rib 20a 3 into connection with the wire H 1 onto its face M 2 . The blow gap can also be profiled, in which case the blow effect is intensified at the desired point. Such points may be the lateral areas of the wire. The third rib 20a 3 is preferably displaceable in the running direction of the wire, in which case the width of the blow gap A 2 can be regulated. It is important that the suction device and the blow device should be placed at the same side of the wire (at the side F 2 ). Then, the blowing is carried out in the direction opposite to the direction of suction of the humid air, said direction being also opposite to the direction of passing of the washing water through the wire. According to the invention, the construction described above is also favourable because the suction device 12 and the blow device 13 are placed close side by side and constitute a compact, unified construction unit, which comprises a unified frame 14 that surrounds the device. Thus, the device is advantageous to construct, and the cost of its transportation to the installation site becomes low. According to the invention, three ribs have been used, of which the middle rib 20a 2 operates both as a component that defines the nozzle opening A 1 of the suction device 12 and as a component that defines the blow-nozzle opening A 2 of the blow device. Thus, the number of the rib components has been minimized. Fig. 2A illustrates the adjustability of the third rib 20a 3 shown in Fig. 1. As is shown in Fig. 2A, the third rib 20a 3 can be positioned in the direction L 2 , in which case the width of the blow gap A 2 can be adjusted by means of said positioning. As is shown in the figure, the third rib 20a 3 is connected by means of a T-joint to the fastening rib 21, which fastening rib 21 is further attached to the displaceable frame part 22, and the displaceable frame part 22 can be positioned in relation to the base frame 14 by means of a screw device 23 or equivalent. The displaceable frame includes a U-section opening 24, through which the screw 23 has been passed and fixed to the frame 14 of the equipment. The ribs 20a 1 ,20a 2 ,20a 3 are attached by means of a T-joint or an equivalent joint to a separate fastening rib 21, which is fixed further to the frame 14 of the equipment, in which case, when the ribs 20a 1 ,20a 2 ,20a 3 are replaced, they can be passed onto the fastening rib 21 from the end of the fastening rib. Fig. 2B shows the equipment of Fig. 2A as viewed in the direction of the arrow K 1 . The displaceable frame part 22 includes a U-section opening 24, through which the screw 23 has been passed. When the screw 23 is opened somewhat, the frame part 22 and the fastening rib 21 attached to it can be positioned in view of adjusting the width of the blow gap A 2 . In the embodiment shown in Fig. 2C, by means of the screw arrangement, the width of the gap can also be adjusted in the cross direction of the machine, in which case it is possible to profile the supply of blow air across the machine width and thereby to regulate the drying capacity in the desired way. Different areas of the wire may have different requirements of drying. Thus, in the way shown in Fig. 2C, the rib 20a 3 may be composed of component ribs 20a 3 ,20a 3 ''..., in which case the blow gap can be shaped as desired by adjusting the component ribs 20a 3 ,20a 3 '',20a 3 '' in relation to the middle rib 20a 2 by means of the screws 23 ,23''. The profiling can also be carried out so that the blow box has been divided into compartments in the cross direction of the machine, into which compartments the air is supplied at different pressures. In such a case, the blow gap may be of invariable width and, yet, the blow capacity can be regulated across the wire width. Fig. 3 is an axonometric view of a construction unit in accordance with the invention. The construction unit 14 shown in the figure and consisting of a suction device and a blow device can be shifted as one compact solution to its site of operation in a paper/board machine. Also, at the opposite side of blowing (side F 1 ), there may be a suction box 100 so as to guide the blow air into the interior of the suction box 100 and further out of connection with the equipment. Fig. 4 shows an embodiment of the invention in which there is a jet guide plate 40 at the vicinity of the jet pipe, which plate guides the wash jet and the mist arising in washing towards the suction opening A 1 of the suction box. The plate 40 extends across the machine width, and its position is adjustable.

Claims: A device (10) for washing a running wire (H 1 ) in a paper/board machine, which device comprises, at one side (F 1 ) of the wire (H 1 ), a wash-nozzle pipe (11) by means of which a washing liquid is sprayed as a jet (S) onto a first face (M 1 ) of the wire (H 1 ), and, at the opposite side (F 2 ) of the wire, a suction device (12) through which mist arising in the washing of the wire is absorbed and removed from the wire, characterized by a blow device (13) through which air is blown onto the second face (M 2 ) of the wire (H 1 ) and through the wire, said blow device (13) being disposed downstream of the wash-nozzle pipe (11) at the same side (F 2 ) of the wire (H 1 ) as the suction device (12) and directly alongside the suction device (12). A device as claimed in claim 1, characterized in that the suction duct of the suction device (12), which terminates in the suction opening (A 1 ), is opened at an acute angle towards the running direction of the wire, in which case the mist arising in washing can be guided efficiently into the suction chamber (D 1 ) of the suction device (12). A device as claimed in the preceding claim, characterized in that there are ribs (20a 1 ,20a 2 ) at both sides of the suction opening (A 1 ). A device as claimed in the preceding claim, characterized in that there are ribs (20a 2 ,20a 3 ) at both sides of the blow opening (A 2 ), the rib (20a 2 ) being preferably fitted to define both the suction opening (A 1 ) and the blow opening (A 2 ). A device as claimed in any of the preceding claims, characterized in that the width of the blow opening (A 3 ) is adjustable. A device as claimed in the preceding claim, characterized in that the width of the blow opening (A 3 ) can be adjusted by displacing the rib (20a 3 ). A device as claimed in any of the preceding claims, characterized in that the rib (20a 3 ) can be positioned by displacing it in the machine direction (L 1 ), in which case the rib (20a 3 ) is connected to a frame part (22), which can be positioned by means of screw means (23) or equivalent so that the frame part (22) and the related rib (20a 3 ) can be placed in different positions in relation to the frame (14) of the device. A device as claimed in any of the preceding claims, characterized in that the ribs (20a 1 ,20a 2 ,20a 3 ) used in the equipment are attached by means of a T-joint or an equivalent joint to a separate fastening rib (21), which is further connected to the frame (14) of the equipment, in which case, when the ribs (20a 1 ,20a 2 , 20a 3 ) are replaced, they can be passed onto the fastening rib (21) from its end. A device as claimed in any of the preceding claims, characterized in that such an arrangement of equipment is provided that, if necessary, at least part of the air that is sucked by the suction device (12) is passed into the blow device (13). A device as claimed in any of the preceding claims, characterized in that such an arrangement of equipment is provided that the amount of air supplied by the blow device across the web width is adjustable, in which case the profile of the drying capacity can be regulated across the width of the wire. A device as claimed in any of the preceding claims, characterized in that, in connection with the jet pipe, there is a plate (40) that is used for guiding the jet/mist.

Inventors: KIVIRANTA SEPPO, KIVIRANTA, SEPPO
Applicants: VALMET CORP, VALMET CORPORATION
Application year: 1996
Main classification: D21F1
IPC codes: D21F1, B08B3, B08B5