DE29612081U1 - Device for cleaning a sieve - Google Patents

Description

Voith Sulzer Paper Machine jjqpbH*,." J .,* *..PA10324

"Screen Cleaner ¹¹

Device for cleaning a sieve

The invention relates to a device for cleaning a rotating screen used to form a fibrous web (e.g. paper web), in particular with the features specified in the preamble of claim 1. The invention is based on the documents DE 40 18 074 and DE 41 01 350.

Attempts have already been made with the known devices to achieve the highest possible cleaning effect with the lowest possible energy consumption and the lowest possible construction costs. The object of the present invention is to achieve even more favorable results in this respect.

This task is essentially solved by the combination of the features mentioned in claim 1. A significant advantage is that only a single ceramic strip is required to guide the sieve belt in the area of the cleaning device. In addition, since a cheap, commercially available element (e.g. a scraper blade) can be used for the cover mentioned in claim 1, very low manufacturing costs are achieved.

A further advantage is the following: The invention makes it possible to create a smooth transition from the slope of the air supply channel to the sieve guide surface of the ceramic strip. This allows an air wedge to form, which reduces the frictional resistance and enables a lower air blow-out pressure than before.

If desired, the water supply device of the device according to the invention can be designed as before as an additional water spray pipe, which injects water into the gusset tapering in the direction of the screen travel between the screen and the cover mentioned. Instead, however, according to a further idea of the invention,

pjp 2781 DSh PA1O324 05.07.96ROhZOa ₁ Oy ₁ SSMeSo (2919P2/1)

The supporting body of the cleaning device according to the invention not only has a cavity for supplying air, but also an additional cavity for supplying water. In addition, a second cover can be provided which - like the first cover - extends from the supporting body into the gusset and forms a water supply gap together with the first cover. This makes it possible to fill the mesh of the sieve belt with water in a simple manner by creating a water film, whereby a lower water pressure is required than before.

Further ideas and embodiments of the invention are described below with reference to the drawing.

Figure 1 shows a screen cleaning device in cross section.

Figures 2, 3 and 5 show modified details compared to Figure 1.

Figure 4 is a detail of a longitudinal section. Figure 6 shows a further modification of Figure 1.

The support body 1, which is designed as a hollow body and is used to supply the blowing air and the water for the water film, is equipped with only a single ceramic strip 2 (resting on a support strip 2') with a sieve guide surface 2a, over which the sieve S is guided.

The water supply 3 for filling the sieve mesh and for producing a water film takes place under low pressure through holes 4 in the supporting body cover plate 5 and the clamping strip 6 into a parallel gap 7, which is formed by two thin plates 8, 9 (scraper blades/steel blades).

The plate ends are set either at a small distance from the screen or slightly adjacent.

pjp 2781 DSh PAI0324 05.07.96 Röh/09.07.96 MeSc (2919P2/2)

The terminal block &bgr; with the separating plates can be removed to change the plates.

The channel height b can be adjusted by changing the thickness of the intermediate bar 10.

The air duct 12 is formed between the ceramic strip and the lower separating plate 9 as well as the guide 11 of the terminal strip.

The air supply for blowing out the water from the sieve S with the dirt particles takes place through the support body 1 via bores 13 in the cover plate 5 into the air duct 12.

The gentle transition from the slope of the air duct to the sieve guide surface 2a of the ceramic strip 2 allows an air wedge to form, which reduces the frictional resistance and enables a lower blow-out pressure than before.

The channel height a ¹ of the air channel 12 can be adjusted by changing the thickness of the plate 9 (see Figure 2). The thicknesses of the partition plates 8 and 9 can be adapted to the required pressure.

It is also possible to design the air duct 12' conically as a nozzle (Figure 3).

Plastic plates 14 are screwed on to seal the front side (Figure 4).

The format width is adjusted either via slider 15 in the feed channels or via slider 16, with which some of the feed holes 13 are blocked in the edge area R (Figure 4).

For use between the screen suction roller and the screen drive roller, to remove the edge band, the number of feed holes 13 in the edge area R (Figure 4) is increased (e.g. double the number) so that more water and more air are automatically fed into this area. The format width can also be adjusted using throttle screws 17, 18 (Figure 5).

pjp 2781 DSh PA10324 05.07.96ROhZOS-Oy ₁ SeMeSc (2S1SP2/3)

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It is also possible to supply water and air at increased pressure via additional lines 19/20 and 21/22 (Figure 6)

To detach the entire web from the screen, the water and air supply is increased via a control system.

The cleaning device is normally mounted in a similar way to a flat vacuum cleaner with the option of adjusting to the sieve S.

The device can also be mounted on pivoting levers for pivoting when changing the ceramic strip 2 or the terminal strip 6 with separating plates 8, 9.

pjp 2781 DSh PA10324 05.07.96 Röh/09.07.96 MeSo (2919P2/4)

Claims (7)

Voith Sulzer Papiermaschinen GmbH PA10324 "Sieb-Cleaner" Protection claims 1. Device for cleaning a rotating screen (S) used to form a fibrous web (e.g. paper web) with the following features: a) a strip (2) extending transversely to the running direction of the sieve (S), which rests on a support body (1), contacts the rotating, endless sieve with a sieve guide surface (2a); b) a compressed air supply device (12, 13) opens onto the bar (2); c) a wedge-shaped gusset tapering in the direction of the sieve travel is formed between the strip (2) and the sieve (S), into which a water supply device (3, 4) opens; d) characterized in that the air supply device (12) has a first cover (9) which extends from the carrier (1) into the gusset and forms an air supply gap (12) with the strip (2). 2) Device according to claim 1, wherein the support body (1) has a first cavity (la) which is part of the air supply device, characterized in that the support body has a second cavity (3) which is part of the water supply device. 3) Device according to claim 1 or 2, characterized in that the water supply device (3, 4, 7) has a second cover (8) which extends from the support body into the said gusset and forms a water supply gap (7) with the first cover (9). pjp 2781 DSh PA10324 05.07.96 Röh/09.07.96 MeSc (2919P2/5) 4) Device according to one of claims 1 to 3, characterized in that the first cover (9) is designed in the manner of a flat leaf spring, scraper blade or the like. 5) Device according to one of claims 3 or 4, characterized in that the second cover (8) is designed in the manner of a flat leaf spring, scraper blade or the like. 6) Device according to claim 4 or 5, characterized in that the free ends of the covers (8, 9) have a small distance from the sieve (S). 7) Device according to one of claims 1 to 6, characterized in that a clamping strip (6) is detachably attached to the support body, which clamping strip carries the cover (9) or both covers (8 and 9). pjp 2781 DSh PA10324 05.07.96 Röh/09.07.96 MeSc (2919P2/6)