Twin wire former

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the angle (β), at which the two wire belts (2, 3) run upward in relation to an imaginary second horizontal plane (H2) after the first deflection device (10), assumes a value between 10° and 90°, preferably between 25° and 40°.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• isobaric dewatering elements (18, 19), as they are known, are arranged between the first deflection device (10) and the separating device (11), between which the forming fibrous web (4) runs, enclosed between the two wire belts (2, 3).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• after the separating device (11), there is arranged at least one flat suction element (20), which acts on the wire belt (2) which carries the forming fibrous web (4).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• at the second deflection device (15), deflection of the wire belt (2) is carried out in such a way that the wire belt (2) subsequently runs downward at an angle (γ) less than 60°, preferably less than 40°, in particular less than 25°, relative to an imaginary second vertical plane (V2).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• a further sheet forming device (22), preferably a hybrid former, is arranged after the second deflection device (15).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the second deflection device (15) is a suction roll (13), a shoe (21) with foils or a shoe with foils and with applied vacuum.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the distance (A) between the lower vertex (10.SU) of the first deflection device (10) and the upper vertex (15.SO) of the second deflection device (15) assumes a value between 1 and 8 m, preferably between 3 and 6 m.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the first deflection device (10) is a closed roll (16), an open roll or an open roll with applied vacuum.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the separating device (11) is designed as a suction separator (17) and/or as a vacuum shoe.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the forming roll (7) has a diameter (D7) of greater than 1200 mm, preferably greater than 1635 mm, in particular greater than 1760 mm.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the forming roll (7) has a dewatering capacity which has a value of at least 50%, preferably of at least 65%, of the total dewatering capacity of the twin-wire former (1).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the forming roll (7) is designed as an open roll.

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• the roll diameter (D16) of the deflection roll (16) is greater than the roll diameter (D7) of the forming roll (7) and/or the roll diameter (D13) of the suction roll (13).

The twin-wire former (1) as claimed in one of the preceding claims,

• characterized in that
• it has an overall height (H) in a range from 2 to 8 m, preferably from 3 to 6 m.

Use of the twin-wire former (1) as claimed in one of the preceding claims, in particular in a former rebuild.