FI56566C - VIRAPARTI I EN PAPPERMASKIN MED BANBILDNING MELLAN TVAO VIROR SOM OMSLUTER EN FORMERINGSVALS - Google Patents

Description

E3SF7] [B] (11) NOTICE] PUBLICATION

ALJU j UTLÄGGNI NGSSKRIFT bODD 6 C (45) Patent granted il C2 1930 i% aiFv Patent meddelat V 'V (51) Kv.lk.' / Int.CI.1 D 21 Ϊ 1/00 FINLAND —FINLAND (21) P «T« nttlhtk * mu * - Paumameknlng 312/72 (22) Hakamispilvt - Antttknlnf * dt | OU.02.72 (23) Alkuplivt — Glltl | h «tfdag 0 ^ .02.72 (41) Become Public - Blivlt offsntllg 07.08.72

Patent- j «reki rter I hall itu, NftaMWp ™» j * monthMullutam pvm.-

Patent- och raglstarttyralaan v 'An * ökan utlifd oeh utl. «Required publication 31.10.79 (32) (33) (31) Pyydetty atuolkaua—

Federal Republic of Germany-Förbundsrepubliken! Iy ski and (DE) P 2105613.3-27 (71) J.M. Voith GmbH, Heidenheim / Brenz, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Christian Schiel, Heidenheim-Schnaitheim, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (7 * 0 Oy Kolster Ab (5 * 0 Wire section in a paper machine between two pennants wrapped around a shaping roller - Viraparti i en pappermaskin med banbildning mellan tvä viror som omsluter en forme-ringsvals

The invention relates to a wire section of a paper machine with an extruded pulp feeder, a forming cylinder with a perforated casing for forming the web, and two wires wrapped around the forming cylinder, which form a feed opening after the discharge point (separation point), wherein each wire in the area between the discharge point and the separation point formed by the suction box or suction roll runs substantially straight, and wherein the outer wire carries with it the formed paper web. The point of separation and the point of exit may be located at a longer distance from each other, but the displacement of the two wires in this direction is completely irrelevant. Only double-wire formers in which the formation of the track takes place essentially by the forming cylinder itself, such as the double-wire former described in DOS 1,809,779 · This means that in addition to the forming cylinder, at most one fixed dewatering part is connected to the front of the cylinder 2 565 (DOS 1 925 UOT) account right after it.

Since the dewatering takes place between two wires, i.e. on both sides of the dewatering gap, a considerable dry matter content is achieved with the double wire designers, despite the relatively short web formation zone of the forming cylinder and possibly a fixed dewatering section connected forwards or backwards. However, the dry matter content at the end of the leaf formation zone is not sufficient to avoid interference causing track interruptions. These disturbances may be due to the fact that at the point of separation, where the uniformly formed fibrous web becomes separated from the second wire together with the second wire, parts are torn from the fibrous web, which again fall back onto the web behind the separation point. The shorter the distance between the point of entry and the point of separation and the higher the speed of the machine, the more difficult the problem becomes.

To solve the problem, one could consider the use of a protective device, such as an assembly line, which would prevent detached parts from falling back onto the track.

However, this is not useful because the parts stick outside the guard and fall off the track again. In addition, there is often not enough space for such tools.

The object of the invention is to invent, in connection with a double wire designer of the type described, measures which avoid the interruption of the track and reduce the susceptibility to interference.

According to the invention, this object is achieved in that the outlet is located in the upper ascending quarter of the forming cylinder to remove particles detached from the paper web at the separation point and that the outer wire is above the inner wire above and that particles which become detached from the track when the track separates from the inner wire cannot fall onto the track itself. On the other hand, they fall on the inner wire, where they cannot cause damage. According to the invention, when the exit point is placed in front of the point of the cylinder of the forming cylinder, it follows that the water is in a way "peeled" off the outer wire before the exit point by a gravity component acting against the direction of travel.

If this is not the case, but the exit point is at or behind the upper legal point, then the water adhering to the outer wire becomes entrained by the gravity component acting in the direction of travel and arrives at the separation point where it can again strike the track and thus damage the separation. Both said features according to the invention thus act together, the purpose of both being to separate the second wire purely together with the formed web from the second wire.

However, a double wire designer is already known in the past, in which the intertwined, outer wire is also the leading wire of the web (DOS 2,000 661). In this case, however, the leaf-forming zone 3 SSS66 extends over the upper, rising quadrants and the upper, descending quadrants, where gravity acts in the direction of travel of the track.

According to the invention, the outer wire is further turned around at the point of separation by means of a suction box or a suction roller, but the inner wire is kept substantially flat. If the area of the suction box or suction roller in contact with the wire is large enough, not only a good removal of the web from the inner wire is achieved, but at the same time additional dewatering.

In the developed form of the invention, the outer wire is turned over by more than 90 ° between the point of separation and the transition point of the felt web. The turning angle can be 180 ° and larger. As a result, an additional advantage of the invention is that the conductive wire of the web rises more or less sharply before the turning point and becomes guided downwards after the turning point. As is generally known in the papermaking industry, this control is advantageous, since in this case also the 1st press felt receiving the web from the wire in direct contact 11a conveys the web below it through the 1st rotary press. This has the advantage that the press roller in contact with the paper, which has to be scraped clean, can be set so that the scraping point is not on the felt and the track.

The invention will be further elucidated with reference to the drawing. Both figures show a shaping cylinder 1 with which a pulp feed nozzle 2 is connected. Two wires 3 and U wrap around the shaping cylinder 1. The two wires form a wedge-shaped inlet slot 5 in the lower region of the shaping cylinder. They pass together away from the shaping cylinder 1 at the exit point 6.

The suction box 7 shown in Fig. 1 has a suction surface 8 with a bend 9. The bend forms a separation point where the outer wire U together with the track 11 formed by the forming cylinder 1 becomes separated from the inner wire 3. As can be seen, the track 11 and the outer wire are located above the inner wire 3. The discharge felt 12 is guided through a fixed suction box 13 to the track 11 and separates it from the outer wire U.

In the double wire shaper shown in Figure 2, only a single suction roll turns the outer wire between the point of separation and the point where the path passes to the discharge felt.

Claims (2)

1. A wire section of a paper machine having an extrudate pulp feeder, a forming cylinder with a perforated casing for forming a web, and two wires wrapped around the forming cylinder, which form a feed opening opening in the lower part of the forming cylinder after the discharge point (separation point), wherein each wire in the area between the discharge point and the separation point formed by the suction box or suction roller passes substantially linearly and the outer wire carries the formed paper web, characterized in that at the discharge point (9) ) in the upper rising quarter of the shaping cylinder (1) and that at the separating point (9) the outer wire (U) is above the inner wire (3). Wire section according to Claim 1, characterized in that the web-supporting wire (U) is turned around by more than 90 ° (at 1U) between the separation point (9) and the web exit point.