FI65831C - PROCEDURE FOR PRESS RELEASE OF FIXED FIBER MATERIALS - Google Patents

Description

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J®Tä l J ° 1) utlAccnimcsskhift Obööl c f4Ä Paten tti myaruic tty 10 07 1924 ^ 3 Patents iwniiniwm-htiimM ^ 1781/73 (22) Htk «mltpUv« —Aiw5lcnln | wlaf 31.05.73 '* (23) Alkuptivt — GUtlgtiMsdag 31.05.73 (41) Interpreters (ulklMfcii - Blhrit offantMg 08 01 74

Patent- och regletarstyreleen ^ Arnttkan λ ££ ΓοΑuti ^ krtfun pub * OTd 30.03.84 (32) (33) (31) Requested etoolkeui — Begird prlortuc 07.07.72

Austrian Österrike (AT) A 5867/72 (71) Maschinenfabrik Andritz Actiengesellschaft, 8045 Graz-Andritz,

Austria-Austria (AT) (72) Alois Wohlfarter, Graz, Austria-Austria (AT) (74) Berggren Oy Ab (54) Roller fitting for presses to remove water from a damp fibrous web - Valsanordning vid pressar vid avvattning av en fuktig fibermaterialbana

The invention relates to a roll arrangement for presses for removing water from a moist fibrous web fed substantially horizontally between two endless webs moving in the same direction over horizontally mounted pairs of rollers, the fibrous web and screen webs passing first in each and the lower rollers are horizontally displaced relative to each other, and the diameters of the upper and lower rollers of the pressing section decrease in the direction of travel of the screen belts.

The purpose of the above-mentioned roll arrangement for presses is to remove water from the fibrous material as simply and quickly as possible. By means of the rollers, the screen strips are pressed against the fibrous material, from which water is thus removed.

To speed up the drainage of water, the pairs of rollers are fitted in a wedge-shaped formation at the inlet end of the device. Thus, the pressure on the web of material increases with each roll. As more and more water is removed at each roll, the volume of the fibrous material also decreases, so that the distance between the rolls of the roll pairs must also be reduced in the feed direction.

2 65831 In such a plant, this wedge-shaped formation is called the wet end, i.e. the register part. This is followed by a pre-pressing section and then, as is known, the main pressing section of the plant. In the pre-compression section, the rollers are preferably arranged displaced relative to each other, in order to improve the compression of the fibrous material. The fibrous material, from which the water has now largely been removed, continues its journey to the main compression section. This consists of a larger pair of roller rollers operating at such a high compression pressure that even more water is squeezed out of the fibrous material.

Such a device is already known as a double belt press from the Austrian patent publication 198 131. In further development of these devices, efforts have been made to further increase their high production capacity per se by uniformly increasing the pressing pressure and the pressing surface applied to the fibrous material by the screen strip. The number of pairs of rollers could be further increased, but this measure is inappropriate due to the fact that the machine would become very large. Therefore, efforts have been made to increase the compression area, to distribute the pressure evenly, and nevertheless to keep the size of the machine as small as possible.

According to the invention, this is achieved in such a way that the vertical wheelbases between the rolls of the pairs of rollers decrease in the same direction, so that the angle of rotation of the screen strips on the rollers of the pressing part continuously increases.

The invention will now be described in more detail with reference to the accompanying drawing, which schematically shows a dewatering device with its roller arrangements. The drawing primarily shows the arrangement of the rollers in the dewatering device.

On the right side of the figure there are rollers 1 mounted in the same horizontal plane, and above these the same number of rollers 2, the distance of which to the rollers 1 below continuously decreases as water leaves the material in its direction of travel. Rollers 1 and 2 have approximately equal diameters, and the distance between the upper and lower rollers always decreases to the last roll 2, where the distance is very small. This grouping of rollers is called the wedge part.

65831 This wedge part is associated with a compression part. Here, the lower rollers 13 are arranged at certain distances from each other. The upper rollers 14 are arranged above the intermediate spaces of the rollers 3. The drive rollers 5 and 6 of the upper and lower screen strips 11 and 12 are further arranged at the end of the press section. The rollers 7 and 8 have upper and lower support rollers 9, 10 and The set of rollers for the upper screen belt 12, for example, thus consists of wedge rollers 2, press rolls 4, drive roller 5 and support roller 9 and pivot roller 7. 1, over the rollers 3 of the pressing part, the drive roller 6, the support roller 10 and the turning roller 8.

As already mentioned, the pairs of rollers 1, 2 are arranged one on top of the other in the wedge part, whereby the distances between the geometric axes of the rollers 1, 2 continuously decrease in the direction of travel of the screen strips 11, 12, so that a wedge-shaped entry occurs. Instead, the rollers 3 and 4 of the pressing part are not mounted one on top of the other, but in the intermediate spaces of each other, i.e. each roll 3 is followed by one of the rollers 4. In this part, too, the distances between the geometric axes of the rollers 3 and 4 continuously decrease in the direction of travel of the screen strips 11, 12. In addition, the diameters of the rollers 3 and 4 continuously decrease in the direction of travel. The advantage of this arrangement is that the angle of rotation of the screen strips (omslutningsvinkel) increases as the removal of water progresses. Due to the decrease in the diameters of the rollers 3, 4, the compression pressure also increases correspondingly. The diameters of the rollers 3, 4 are thus dimensioned according to the dewatering event. In the direction of travel of the screening belts 11, 12, the compression pressure increases in proportion to the degree of drying.

The drive rollers 5 and 6 are mounted relative to the last roll 3 so that the screen strips 11, 12 between this last roll 3 and the drive rollers 5 and 6 form an obliquely downward outlet for the dried pulp, as indicated by the dashed arrow.

The double arrow on the last roll 4 indicates that this roll can be adjusted vertically, and the other double arrows illustrate that the turning rollers 7, 8 can be set horizontally. The directions of rotation of the drive rollers are indicated by arrows, and the arrows in front of the wedge part between the screen strips 11, 12 indicate the direction of fiber supply.