DE3239954C2 - Roller press for webs of paper, textiles or the like. - Google Patents

Abstract

Roller press, especially for paper webs, with a cylindrical press roller (1) and with a press shoe (4) which can be pressed against it and which is guided in a stationary, roller-shaped support body (3). Through the press nip located between the press roll (1) and the press shoe (4), an endless, tubular, circumferential sliding belt is passed, the edges of which are each attached to a disc (7) rotatably mounted on the support body (3). In the area of the edges of the sliding band (5), the press shoe (4) has a freely cantilevered arm (6) which supports the relevant edge area of the sliding band.

Description

a) the press shoe (4) is guided in a stationary support body (3) which is approximately cylindrical Has shape;

b) on the side of the press shoe (4) opposite the contact surface there is one with a pressure chamber (4a) which can be filled with pressure medium;

c) an endless one revolving around ö & n supporting body (3) Gieitband (5) is passed through the PreBspait;

d) the edges of the sliding band (5) are, as is known per se, attached to a rotary body (7) each, which is rotatably mounted on the support body (3);

characterized,

e) that the press shoe (4) in the region of the edges of the sliding end (5) is one freely cantilevered Arm (6) which supports the relevant edge area of the sliding band.

2. Roller press according to claim I. characterized in that that the freely projecting arms (6) under the influence of the tension of the Glcitbandes (5) are elastically deformable.

■ 3. Roller press according to claim 1 or 2, characterized characterized in that the two arms (6) thicken towards the main body of the press shoe (4).

4. Roller press according to one of claims 1 to 3, characterized in that the sliding belt (5) supporting support surface of the arm (6)

a) in the area of the lateral end of the press gap, corresponding to the shape of the pressing surface of the Press shoe (4), concave shaped, (Fig. 2),

b) on the other hand, has a convex shape at its outer end (Fig. 3),

c) whereby the two forms merge steadily into one another.

The invention relates to a roller press for webs of paper, textiles or the like. According to the preamble of Claim 1. Such a roller press is known from document WO 82/02567. The one in such a The press zone formed by the roller press has a certain longitudinal extent in the running direction of the paper web to be treated, thanks to the concave shape (corresponding to the cylindrical V / alzenmantel of the press roll) Contact surface of the press shoe. In the direction transverse to the running direction of the paper web corresponds to Length of the press zone the width of the paper web.

Various, very different requirements are placed on roller presses of this type: First of all it must be ensured that the sliding tape can easily circulate around the support body without that the sliding band warps or wrinkles. For this purpose, it is common to adjust the width of the sliding band in known way (DE-OS 19 23 784 or 30 30 233, Fig. 2) to make greater than the length of the press shoe and the edges of the sliding band on each one rotation body, z. B. Washer to attach the au! to the Support body are rotatably mounted. If closed

ίο discs are used, there is the possibility of to put the interior under a certain internal pressure. The sliding band is hereby tensioned to a certain extent, in particular in the longitudinal direction, i. H. across the direction of rotation, which makes it more secure Another requirement is that the pressing force acting on the paper web over the width of the paper web should be as uniform as possible. To achieve this, according to DE-OS 30 30 233, the effective one makes Length of the pressure chamber which acts on the press shoe, as exactly as possible equal to the effective length the contact surface of the press shoe (this length is usually equal to the largest possible width of the paper web). In order to achieve this, one was previously forced to use the concave-shaped contact surface of the To delimit the press shoe as clearly as possible at both ends. I. E. which are parallel to the edges of the paper web running edges of the press shoe could only be rounded off slightly. This resulted in the following Problem on: On the one hand is the orbit of the sliding belt a substantially natural circular path in its edge regions; because it is, as mentioned, attached in these areas to the said bodies of revolution. The sliding band is in the area of the press zone on the other hand, forced to deviate from the circular orbit and the concave shaped contact surface to follow. Thus, the sliding tape suffers at the edges of the pressure surface that are parallel to the paper running direction a considerable spatial dimension. It is therefore, in these two areas, the demand

40 · as in the other zones, so that the danger premature wear and tear.

Previous attempts to prevent this risk:

1. According to DE-OS 30 30 233, the press shoe consists of a rubber-like elastic material; from it however, there are other problems.

2. Consideration was given to using the edges of the press shoe to protect the sliding band large rounding radii / u. But then you have to accept the disadvantage that the length of the pressing surface becomes smaller than the length of the pressure chamber; but this should be derived from the reasons mentioned above should be avoided. (The pressing force would no longer be sufficiently uniform

5'i distributed over the width of the paper web.)

3. In the known arrangement according to US-PS 43 30 023, the sliding belt is guided over several rollers in such a way that /.was the spatial one described Deformation does not occur; however, the structural effort required for this is considerable.

The invention is therefore based on the object of eliminating the risk of wear described above without adf the attachment of the sliding tape edges to the named To have to do without rotating bodies and without the uniformity of the pressing force distribution suffers over the width of the paper web.

This object is achieved according to the invention by the

Features of the characterizing part of claim 1 The sliding band is released by the protruding arms in the critical transition area between the zones different circulation paths supported, so that the risk of wear is largely eliminated In longitudinal section seen, the support surfaces of the two arms can form a continuous continuation of the contact surface, however, they are gently curved toward the axis of rotation of the rotating bodies. Another advantage The invention is that the possibility remains, the effective length of the pressure chamber as precisely as possible to make equal to the effective length of the contact surface of the press shoe, so that it is as uniform as possible Press force distribution is achieved. In some circumstances, however, the pressure chamber can also be shorter than that Be contact surface. The opposite case, in which the pressure chamber is significantly longer than the contact surface however, is avoided.

Appropriate refinements are set out in the subclaims specified.

The features of claim 4 are of particular importance. This ensures that the risk of wear and tear on the sliding band is almost completely eliminated because the previous one through the four corners of the contact surface of the press shoe caused stress concentration and the high alternating bending stress are now significantly reduced

The invention is explained in more detail below with reference to the drawing

The F i g. 1 shows a roller press in a longitudinal section running transversely to the direction of travel to the paper web according to line I-I of FIG. 2.

The F i g. Figure 2 shows a cross section along the line 11-11 of Fig. 1.

3 shows a cross section along the line III-III of FIG. 1.

The roller press consists essentially of a cylindrical press roller 1 with an axis of rotation 2, also one essentially cylindrical fixed support body 3, one embedded therein, against the press roll 1 press-on press shoe 4 and aur one of the fixed support body 3 and the press shoe 4 wrapped around it endless sliding belt 5. The press roller 1 and the press shoe 4 together form a press nip, through which the sliding band 5 and also the paper web 10 to be dewatered (guided on both sides through two felt belts 11 and 12) are passed through. In Fig. 1 is only indicated schematically that the press roll 1 in a bearing 13 which is supported on a machine frame 14, and that the support body 13 in Pivoting levers 15 rests so that it is pressed against the press roller 1 or can be lifted off from it.

The press foot 4 has on both of its edge areas each has a freely cantilevered arm 6 which supports the relevant l ^ and of the sliding band 5. According to Fig. 1 sim <l the arms 6 with the rest of the press shoe body 4 formed in one piece. But they can also be attached subsequently to the press shoe body 4 as separate parts be set. In this case they can if necessary be made of elastically deformable material (e.g. plastic).

The sliding band 5 is fastened to an end disk 1 at each of its two edges. Of these end disks, FIG. 1 only visible. The end disks 7 are mounted on the stationary support body 3 in bearings 8 and can thus rotate together with the sliding band 5. The outside diameter of the end disks 7 in the illustrated embodiment is slightly smaller than the outside diameter of the support body 3. However, these two outside diameters can also be chosen to be the same size.
A pressure chamber 4a delimited by seals is formed between the press shoe 4 and the support body 3. Pressure medium can be supplied to this via a channel 46 in order to thereby press the press shoe 4 against the press roll 1. The length of the part of the press shoe 4 acted upon by the pressure medium is denoted by L. This is also the effective length of the contact surface of the press shoe 4. The support surfaces of the freely cantilevered arms 6 adjoin this Ar.preßfläche on both sides; these are rounded (viewed in longitudinal section, FIG. 1) with a very large radius of curvature R , ie curved in the direction of the axis of the support body 3. Preferably, the extreme ends of the two arms 6 are not touched by the sliding band 5. 1 it can also be seen that the width B of the paper web 10 is only slightly smaller a '= · the length L of the Ar.preßfläche

Of course, care will be taken to ensure that the contact surface of the press shoe touched by the sliding band 5 4 and the support surfaces of the arms 6 form a single, continuous surface. The in F i g. 2 shown The cross section runs through the arm 6 at the point where the contact surface is in the support surface of the arm 6 passes. There the support surface of the arm 6 has the same concave shape as the contact surface of the Press shoe 4. This is due to the cylindrical shape of the press roller 1. The cross section shown in FIG cuts the arm 6 near its outer end. There is the support surface, in contrast to FIG. 2, convex shaped, in adaptation to the essentially cylindrical shape of the support body 3. It goes without saying that that in the area between the sectional planes II and III there is a smooth, steady transition from one to the other Shape of the arm 6 is provided.

1 sheet of drawings

Claims (1)

Patent claims: 1. Roller press for webs of paper, textiles or the like. With a cylindrical press roller (1) and with a press shoe (4) which can be pressed against this and which is connected to the roll shell of the press roll (1) Formation of a press board of a certain length (in the circumferential direction) a concave one Has contact surface, furthermore with the following features: