FI104505B - Channel for paper machine / board machine - Google Patents

Description

104505

Paper machine / board machine duct En duct i samband med en pappersmaskin / board machine 5

The invention relates to a channel in connection with a paper machine or board machine through which fibrous water is led from the wire part of the paper machine / board machine to the wire well.

In prior art solutions, fiber-containing return water is led from the wire section to the wire well 10 through high flow cross-sectional channels. The channels comprise removable cover covers. The channels are preferably rectangular cross-sections. Depending on the amount of water, a variable height air / water boundary layer is formed in the duct, whereby dirt is deposited on the duct walls at the boundary layer and further adversely affects paper machine / board machine operation.

15 This application proposes an improvement to the above problem. The application proposes the use of a water channel in which air and water are separated by a partition. The partition wall is preferably a movable structure, being in one embodiment of the invention formed by a flexible rubber hose. The rubber hose will flex due to changes in water volume 20 and keep the water separate from the air. A rubber hose is attached to the duct walls. In another embodiment of the invention, the rubber hose may also be a free-floating raised structure within the duct.

The channel structure according to the invention is characterized by what is claimed in the patent claims 25.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, but which are not intended to be limited thereto.

Fig. 1A schematically shows a short circulation of a paper machine / board machine, the channel of which enters a wire well according to the invention.

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Figure IB is an enlarged scale view of a prior art wire well channel.

Fig. 1C shows a solution according to the invention for preventing the accumulation of dirt on the inner wall of a duct.

Figure ID is a sectional view I-I of Figure 1C.

Figure 2 shows another preferred embodiment of the invention.

10

Figure 3A shows a third preferred embodiment of the invention consisting of an air-filled hose. Figure 3A shows a flow position.

Fig. 3B shows the arrangement of the device of Fig. 3A at a higher flow rate, whereby the air-filled hose 15 has elongatedly moved to the open top of the duct.

Figure 4A illustrates an embodiment of the invention in which a compressible air-filled hose is located in a duct, at its upper end, with the duct closed in cross section.

Figure 4B shows the state of the inflatable hose of Figure 4A at the top of the duct with a larger volume of water.

Figure IA is a schematic representation of the water circulation of a paper machine / board machine. The channel 10 is arranged between the wire section 11 and the wire well 12 as a return channel for fibrous water 25 from the wire section 11 to the wire well 12.

Fig. 1B shows a channel 10 on the inlet side of the wire pit 12 of Fig. 1A in an axonometric partial view. In the prior art solution, dirt builds up on the inner surface of the channel 10 of the liquid-air interface.

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Fig. 1C shows a solution according to the invention for preventing the accumulation of dirt. The resilient wall 13 is disposed in channel 10.

Figure ID shows a cross-section I -1 of Figure 1C. As shown in the figure, the resilient wall 13 is fitted to the channel 10 so that the ends 13a1 and 13a2 of the wall 13 are connected to the bottom wall 10aj of the channel 10 having a rectangular cross-section and vertical to the angles Ej and E2. The wall 13 separating the water space and the air space is a flexible, preferably rubber mat that adjusts to the amount of water flowing in space Dj. In addition, in Fig. 1D, a loose ceiling is shown with reference numeral 10a ^. In the figure, the second boundary position of the flexible wall 13, which is achieved with a greater amount of water, is shown in broken lines 10 tj.

Figure 2 illustrates another embodiment of the invention in which a flexible wall 13, preferably a rubber mat 15, is attached to the upper edges J 1, J 2 of the vertical walls 10a2 and 10a3 of the duct so that said flexible structure is U-shaped and resting on its flange Dj of airspace D2.

Fig. 3A illustrates an embodiment of the invention in which the air-filled hose Mj is placed inside a channel 10 having a rectangular cross-section and is arranged to float freely on the water space Dj according to the amount of water.

Fig. 3B shows an inflatable hose Mj which has been transferred to the upper part of the channel 10 with more water.

Figure 4A and 4B show an otherwise similar embodiment to Figure 3A but with the figure. In the solution, the inflatable hose M2 is located inside a channel 10 comprising four walls and, depending on the amount of water in the water space Dj, the hose M2 is compressible such that the condition of the inflatable hose M2 shown in FIG. Essential in all of the above embodiments is to prevent the formation of a 30 air / water boundary layer in the duct 10 using a separate partition 13, 104505 4 that separates the air and water space Dj, Dj and follows the water height so that no harmful dirt collecting air and the water boundary layer.

Claims (8)

Channel (10) in connection with a paper machine or board machine through which fibrous water is led from the wire section (11) of the paper machine / board machine to the wire well (12), characterized in that the channel (10) comprises a wall (13) (Dj) and airspace (D2), thereby preventing the formation of a boundary layer of dirt collecting water and air on the duct walls. Channel according to claim 1, characterized in that the wall (13) following the water level 10 is formed by a flexible structure which deforms according to the water level. Channel according to the preceding claim, characterized in that the flexible wall (13) is a rubber mat which is fixed at its edges to the angles (E 1, E 2) of the channel (10) having a rectangular cross-section 15. Channel according to claim 1, characterized in that the wall (13) for monitoring the water level is connected to the upper edges (J1, J2) of the side walls (10a2 and 1033) of the channel (10) having a rectangular cross section, shaped above the surface of the water and follows its height. via channel changes (10). Channel according to one of the preceding claims, characterized in that the channel is open at the top or comprises a removable cover (10a ^) and that the channel (10) has a rectangular cross-section. 5, 104505 Channel according to one of the preceding claims, characterized in that the wall (13) which follows the water level in the duct is an elevation which follows the height of the water surface by floating in water. 30 104505 Duct according to the preceding claim, characterized in that the float is an inflatable hose (Mj). Duct according to Claim 1, characterized in that the wall (13) following the water level 5 consists of a compressible air-filled hose (M2). 104505