FI93041C - Calendar - Google Patents

Description

93041

Kalan ten Kalander 5

The invention relates to a calender.

A TG or soft calender consists of two consecutive nips. When renewing the machine calender of an old paper machine into either a two-nip hot calender, i.e. the so-called TG-kalante-10 or soft-fish blades, the difficulty is often the lack of space. In the past, solutions have also been presented in which the two nips in question are mounted on top of each other. The paper web comes horizontally into the nip between the hot roll and the soft roll and passes from the above nip in a loop to another nip between the hot roll and the soft roll below the hot roll. In the case of the above-mentioned solution, the head 15 of the paper web becomes a problem. The transport of the headband and tin ribbon from the top to the bottom is difficult to perform.

Thus, the problem is either a large space requirement or, if the rollers are placed on top of each other, the difficulty of exporting the head.

20 The present application seeks to find a solution to both of the above problems. According to the invention, a calender is formed in which the nips are superimposed on the same line in a vertical plane and in such a way that the web from the first nip is guided directly vertically to the second nip. According to the invention, a calender is formed with two vertical body parts, wherein movable rollers are attached to the first body part. The rollers are attached to the frame by means of levers. An actuator, preferably a hydraulic cylinder, is connected between the levers and the body, whereby the nip loads can be adjusted by acting on the levers by adjusting the force and stroke length of the hydraulic cylinder. Nipples can also be opened with hydraulic cylinders. There are mechanical stops under the levers, so that the movable rollers can be reliably moved into nip contact with the counter rolls, the stops acting as safety arrangements which determine the second extreme position of the lever mechanism.

2 93041

The calender according to the invention is mainly characterized in that, when the nips are closed, the nip rolls are arranged to be in the same horizontal plane with their axes of rotation and that the nip rolls are respectively arranged to be located below the nip and in the same horizontal plane with their axes of rotation.

5

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

Figure 1A shows a prior art calender solution in which the nips N1 and N2 are located in the same horizontal plane.

Fig. 1B shows another prior art solution, in which space is saved compared to the solutions of Fig. 1A when the nips N1, N2 are superimposed in the same vertical plane, but in which the difficulty is to control the headband.

Figure 2 shows a calender according to the invention, in which the nips N1, N2 are located in the same vertical plane and in which solution the web is guided vertically directly from the first nip to the second nip.

20

Figure 3 shows another embodiment of a calender according to the invention.

Figure 1A shows a prior art calender solution, which may be a TG calender or a soft calender. The nips Nj and N2 25 between the hot roll and the soft roll are successively located in the same horizontal plane. The web Rj is guided through the nip Nj between the hot roll At and the soft roll A2 directly to the nip N2 between the soft roll A3 and the hot roll A4. The above solution takes up a lot of space horizontally. Thus, for example, for calender renewals, lack of space becomes a limiting factor for machine renewals.

• · 30 tsp: 93041 3

A solution to the above problem has been proposed shown in Fig. 1B, in which the web Rj is guided to the first nip Nj between the hot roll Aj and the soft roll A2 and nip Nj along the surface of the roll A2 to the soft roll A3 and along the surface of the soft roll A3 to the nip between the soft roll A3 and the hot roll A4 N2. The solution presented above saves space when the nips Nj and N2 are located in the same vertical plane and when all the rollers Aj, A2, A3 and A4 are located on top of each other. A major difficulty in the above solution is the export of the end of the paper web, because the web R} must be taken from the roll A2 in a loop-like manner to the roll A3. A problematic free travel distance e is formed between the rollers A2 and A3 in terms of web head removal, because the rollers A2 and A3 as soft rolls cannot be in contact with each other.

Figure 2 shows a solution according to the invention, which avoids the problems occurring both in the prior art of Figure 1A and in the prior art of Figure 1B. Referring to Figure 2, the nips N15N2 are closed. According to the invention, the web R is introduced on the roll 11,12 above the calender 15 into the nip Nj between the rollers 11 and 12 and is guided vertically downwards from said nip Nj as a web run Ra to the nip N2 between the rolls 13,14 located below. In the solution of Figure 2, the roll 11 is a soft roll and thus the web R can be introduced horizontally onto the roll 11 and along the surface of the roll 11 to the nip Nj between the roll 11 and the roll 12, the roll 12 being a hot roll. Pinch N! the web R20 is transferred as a vertical web run Ra to the nip N2 between the rollers 13 and 14 below. Correspondingly, from the nip N2, the web is guided along the surface of the roll 14 so that the web diverges in the direction of the circumferential tangent of the roll 14 as a web run Rb after passing on the roll surface by about 90 °. Roll 14 is a soft roll and roll 13 is a hot roll, respectively. When using hot calendering, the web can only be in contact with the hot roll for a short time. The above-mentioned roll arrangement acts alternately on the hot roll roll on each side of the paper web R and also ensures that the web is only in contact with the hot roll 12,14 in the nip N1, N2. The nips Nj and N2 are located in the same vertical plane Y. The rollers 11 and 12 are located in the same horizontal plane Xt with their central axes Gj and G2 and the rollers 13 and 14 are located in the same horizontal plane X2 with their central axes G3 and G4. The examination is made when the nips NltN2 between the rollers 11 and 12 and between the rollers 13 and 14 are closed.

4,93041

The calender 10 comprises body parts 10a and 10b. Rollers 11 and 13 are mounted on the lever arms 15 and 16 of the body portion 10a by bearings 17 and 18. The lever arm 15 is articulated to pivot from the hinge point 19a relative to the body 10a. An actuator 20, preferably a hydraulic cylinder, is connected between the lever arm 15 and the body 10a. The cylinder 20 moves the lever arm 15. The lever arm 16 is articulated to pivot at the hinge point 19b relative to the body 10a. Correspondingly, an actuator 21, preferably a hydraulic cylinder, is connected between the lever arm 16 and the body 10a. The cylinders 20 and 21 are articulated from the articulation points Ct and C3 to the body 10a and from the articulation points C2, C4 to their lever arms 15,16.

By acting on the hydraulic cylinder 20, the lever arm 15 is moved and the roll 11 is moved. The cylinder 20 is used to open and close the nip N1 between the rollers 11 and 12 and to adjust the nip pressure in the nip Nj. By means of the hydraulic cylinder 21, the lever arm 16 is moved and the nip N2 between the rollers 13 and 14 is opened and closed and the nip pressure in the nip N2 is adjusted. By changing the dimensions and position of the lever arm 15,16 with respect to the body 10a and by changing the connection points and directions of the hydraulic cylinders 20 and 21 15, the movement distances and nip forces of the rollers 11 and 13 can be influenced already in the design phase of the calender 12. Below the levers 15,16 are mechanical stops 24a, 24b in the body 10a. They determine the second extreme positions of the rollers 11,13 with the lever arms 15,16 in the extreme position against the stop 24a, 24b. The rollers 12 and 14 are in a fixed position with respect to the body 10b 20 and are mounted for rotation by bearing means 25 and 26. The nips N1 and N2 are traction nips, the rotation of the roll being traced to one or both of the nip rollers 11,12; 13.14.

Fig. 3 shows another embodiment of the invention which is otherwise similar to the embodiment of Fig. 2 except that the calender comprises spreading rollers 22 and 23. The paper web R is introduced onto the spreading roll 22 and passed from the spreading roll 23 as a approximately vertical web run Rc to the nip Nt between rollers 11 and 12. Since the web run Rt is vertical, the web does not come into contact with the roll 11 or 12 other than in the nip Nj. Thus, either of the rollers 11 or 12 may be a hot roll. Between the nip Nt and N2 30 there is a second spreading roller 23, from which the web is led to the nip N2 between the rollers 13 and 14. From the nip N2, the web is guided along the surface of the soft roll 14 for a distance of about 90 °. From the roll 14, the web R is guided in the direction of the circumferential tangent of the roll 14 as a horizontal web run away from the connection of the calender 10.

Claims (8)

A calender comprising at least two roll nips (Nj, N2 ...) between which a paper web (R) is introduced on a paper web surface treatment line, which calender comprises such nips between rolls (11,12; 13,14 ...) (Nj, N2 ...), which are superimposed in the same vertical plane (Y), whereby during operation the paper web (R) is passed in a vertical web run (Ra) from the upper nip (Nj) to the lower nip (N2), characterized in that the nips (Nj, When N2 ...) is closed, the rollers (11,12) of the nip (Nj) are arranged to be in the same horizontal plane (Xt) with their axes of rotation (Gj, G2) and that the rollers (13,14) of the nip 10 (N2) are arranged to be located below the nip (Nj) and in the same horizontal plane (X2) as its axes of rotation (G3, G4). Calender according to Claim 1, characterized in that the web (R) is introduced into the first nip (Nj) in a horizontal web run (Rj) and fed 15 nips (Nj) to the first roll (11), and along the roll (11) by about 90 °, the roll (11) is a soft roll and the second roll (12) of the nip (Nt) is a hot roll, whereby the paper web is in contact with the hot roll (12) only in the nip (Nj) and the web is led from the nip (N 1) in a vertical web run (Ra) below to the second nip (N 1 and from the nip (N 2) along the soft roll (14) by about 90 ° and further away from the roll (14) in the circumferential tangent of the roll 20. Calender according to one of the preceding claims, characterized in that the calender comprises, before the first nip (Nj), a spreading roll (22), the spreading roll (22) being arranged above the nip (Nj), whereby the web can be led directly to the nip (Nj) without coming into long-term surface contact with either of the nip rolls (11 or 12), and in which case either of the rollers (11 or 12) may be a hot roll in the cutter blade (10) and the web is guided from the nip (Nj) in a vertical web run (Ra) to below to the nip (N2) and further out of the nip (N2). Calender according to one of the preceding claims, characterized in that the calender comprises body parts (10a, 10b), the lever body (15, 16) of the articulation points (19a, 19b) being connected to the second body part (10a) and that rollers (11,13) are mounted on the lever arms (15,16) by bearings (17,18). Calender according to the preceding claim, characterized in that there is an actuator (20, 21), preferably a hydraulic cylinder, connected between the lever arm (15, 16) and the body (10a), the actuator (20, 21) being used to move the lever arm (13,16) and a roller (11,13) mounted thereon. Calender according to the preceding claim, characterized in that the hydraulic cylinder 10 as an actuator (20, 21) is connected from the articulation point (C1, C3) to the body part (10a) and from the articulation points (C2, C4) to the lever arm (15, 16). 6 93041 Calender according to one of the preceding claims, characterized in that the device comprises a stop (24a, 24b) in connection with the body (10a) which determines the second extreme position of the lever arm (15, 16) when the nip (Nj.N1) is closed by the lever arm (15, 16) when positioned against the stop (24a, 24b). 8 93041