Sealing strip for sealing a positive or negative pressure zone of a roller, roller with such a sealing strip, and method for operating the roller

Abstract

A sealing device for sealing a positive or negative pressure zone of a roll for a machine for producing or processing a fibrous web includes a sealing strip and a lubricating device for introducing a lubricant between an inner surface of a roll shell and a sealing surface of the sealing strip when used as intended. The lubricating device includes a plurality of lubricant outlet openings and can be connected to a supply line for supplying lubricant. The lubricating device can be connected to the supply line through a plurality of inlets which are distributed over the length of the sealing strip. The sealing strip has a first and a second longitudinal-side end and the distance from at least one longitudinal-side end, preferably both longitudinal-side ends, to an inlet is at most 800 mm. A roll and a method for operating a roll are also provided.

Claims

1. A sealing device for sealing a positive or negative pressure zone of a roll or a machine for producing or processing a fibrous web, the sealing device comprising: a supply line for supplying a lubricant; a sealing strip having a sealing surface, first and second longitudinal ends, a length, and a plurality of mutually adjacent inlets distributed over said length of said sealing strip and spaced apart by distances therebetween; one or both of said longitudinal ends of said sealing strip each being spaced apart from a respective one of said inlets by at least 20 mm and at most 1000 mm; each longitudinal end being supplied by a respective one of said inlets being closer to said longitudinal end than said distances between said mutually adjacent inlets; and a lubricating device to be connected through said plurality of inlets to said supply line for introducing the lubricant between an inner surface of a roll shell of the roll and said sealing surface of said sealing strip during operation, said lubricating device having a plurality of lubricant outlet openings.

2. The sealing device according to claim 1, which further comprises one or both of said longitudinal ends of said sealing strip each being spaced apart from a respective one of said inlets by at least 50 mm and at most 800 mm.

3. The sealing device according to claim 1, which further comprises one or both of said longitudinal ends of said sealing strip each being spaced apart from a respective one of said inlets by 600 mm or less.

4. The sealing device according to claim 1, wherein said lubricating device is provided wholly or partly in or on said sealing strip or said lubricant outlet openings are formed in said sealing strip.

5. The sealing device according to claim 1, wherein said sealing strip has a longitudinal direction, and said inlets are spaced apart from one another in said longitudinal direction of said sealing strip by less than 2 m.

6. The sealing device according to claim 1, wherein said sealing strip has a longitudinal direction, and said inlets are spaced apart from one another in said longitudinal direction of said sealing strip by less than 1.75 m.

7. The sealing device according to claim 1, wherein said sealing strip has a longitudinal direction, and said inlets are spaced apart from one another in said longitudinal direction of said sealing strip by 1.5 m or less.

8. The sealing device according to claim 1, wherein said sealing strip has a longitudinal direction, said inlets include adjacent inlets, and said adjacent inlets are separated from one another in said longitudinal direction of said sealing strip by spacings being identical or differing by no more than 500 mm from one another.

9. The sealing device according to claim 1, wherein said lubricating device is provided wholly or partly in or on said sealing strip or said inlets are provided in said sealing strip.

10. A roll for a machine for producing or processing a fibrous web, the roll comprising: a positive or negative pressure zone; and a sealing device according to claim 1 for sealing said positive or negative pressure zone.

11. A method for operating a roll for producing or processing a fibrous web, the method comprising: providing a roll according to claim 10; and supplying said lubricating device with less than 2.4 l/min/m of lubricant.

12. The method according to claim 11, which further comprises supplying the lubricating device with between 0.4 l/min/m and 1.5 l/min/m of lubricant.

13. The method according to claim 11, which further comprises: supplying said lubricating device with 2.4 l/min/m or more of lubricant over a starting time period; and reducing the quantity of lubricant, after the starting time period, to less than 2.4 l/min/m.

14. The method according to claim 13, which further comprises reducing the quantity of lubricant, after the starting time period, to between 0.4 l/min/m and 1.5 l/min/m.

15. The method according to claim 13, wherein the starting time period is at least 30 seconds.

16. The method according to claim 13, wherein the starting time period is between 30 seconds and 5 min.

Description

(1) The invention will be explained in more detail below by using schematic drawings, the invention not being restricted to these embodiments.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(2) FIG. 1 shows a detail of a roll according to one aspect of the invention

(3) FIG. 2 shows a detail of a roll according to a further aspect of the invention in which an inner section of a supply line tapers continuously over its length;

(4) FIG. 3 shows an enlarged a detail of a roll according to a further aspect of the invention showing a sealing strip disposed in a holder and pressed against the inside of a roll shell; and

(5) FIG. 4 shows a detail of a roll according to a further aspect of the invention indicating spacings between the inlets and distances between the inlets and the ends of the sealing strip.

DETAILED DESCRIPTION OF THE INVENTION

(6) FIG. 1 shows a roll 1 having a roll shell 11 and an end face 12. Such a roll can be, for example, a suction roll 1. A sealing device 2 is provided in the interior of the roll 1. The former comprises a sealing strip 3, which is arranged in a sealing strip holder 3a, and a lubricating device 4. The lubricating device 4 shown in FIG. 1 is largely located in the sealing strip 3. A multiplicity of lubricant outlet openings 5 are arranged beside one another. These openings 5 are placed such that the emerging lubricant gets between the sealing surface of the sealing strip 3 and the roll shell 11. For the supply of the lubricating device 4 with lubricant, e.g. with lubricating water, a supply line 6 is provided, which comprises an inner section 7 which extends in the interior of the roll shell 11, and has a storage volume of at least 500 cm.sup.3/m, in particular of at least 2000 cm.sup.3/m, based on the length of the sealing strip, and an outer section 8. Via a plurality of inlet segments 9, 9a, the lubricating device 4 is connected to the inner section 7 of the supply line 6 at a plurality of inlets 10, 10a. In advantageous embodiments, the spacings of two adjacent inlet segments 9, 9a and/or two adjacent inlets 10, 10a can each be equal. Alternatively or additionally, provision can also be made for the inlet segments 9, 9a to be arranged such that their spacing from one another in the longitudinal direction of the roll 1 is less than 2 m, in particular less than 1.75 m, preferably 1.5 m or less. The spacing of an inlet segment 9a or an inlet 10a from a longitudinal end of the sealing strip 3 can preferably be at most 800 mm, in particular at most 600 mm, preferably 400 mm or less.

(7) The inner section 7 of the supply line in FIG. 1 comprises a pipe-shaped part. This pipe advantageously be made of a material (e.g. metal or plastic) which is more rigid than the inlet segments 9, 9a. It is possible, for example, to use pipes having internal diameters of 25 mm (corresponding to a storage volume of about 500 cm.sup.3/m), 40 mm or 50 mm (corresponding to storage volume of about 2000 cm.sup.3/m). The inlet segments 9, 9a can be designed, for example, as hose segments.

(8) FIG. 2 differs from FIG. 1 in that the inner section 7 consists of a pipe 7 which tapers continuously over its length.

(9) FIG. 3 shows a sealing strip 3 in a holder 3a, which is pressed against the inside of the roll shell 11 of the roll 1 by means of a pressure hose 13. Such a use of a pressure hose for pressing onto a moving surface such as a roll shell is a measure which is usual and known to those skilled in the art. As distinct from the embodiments shown in FIGS. 1 and 2, in FIG. 3 the lubricating device 4 is not integrated into the sealing strip. The lubrication is implemented by means of a number of spray nozzles, which provide the outlet openings 5. The spray nozzles are connected to the inner section 7 of the supply line via inlet segments 9.

(10) A further advantageous feature which, in FIG. 3, is implemented together with the spray nozzles but which is also possible in combination with a lubricating device 4 integrated into the sealing strip 3, consists in the inner section 7 of the supply line extending at least partly at least partly on or in the sealing strip holder 3a. This inner section 7 provides the storage volume of at least 500 cm.sup.3/m, and can, for example, have the form of a cylinder or a tapering cylinder.

(11) In FIG. 4, essential components of the invention are illustrated, once more schematically. In a sealing strip 3 with an integrated sealing device, the lubricant outlet openings 5 are supplied with lubricant via inlets 10, 10a. The inlets 10, 10a are connected to the inner section 7 of the supply line via inlet segments 9, 9a. The spacings of the longitudinal end of the sealing strip 3 from the first inlet 10a and from the first inlet segment 9a are designated by d1 and d5, while the spacings of adjacent inlets 10, 10a and adjacent inlet segments 9, 9a from one another are designated by d2, d3, d4. The number of four inlets here is exemplary. It is entirely possible for more or fewer inlets/inlet segments to be provided

(12) The following table indicates some advantageous spacings of the inlet segments and the inlets.

(13) TABLE-US-00001 Example no. d.sub.1 d.sub.2 d.sub.3 d.sub.4 d.sub.5 #1 400 mm 1360 mm 1360 mm 1360 mm 400 mm #2 640 mm 1200 mm 1200 mm 1200 mm 640 mm #3 540 mm 1250 mm 1300 mm 1250 mm 540 mm

(14) As it can be seen, the “inner” spacings d2-d4 can be equal or differ by a few millimeters. This can be necessitated, for example, by the installation situation.

LIST OF DESIGNATIONS

(15) 1 Roll 2 Sealing device 3 Sealing strip 3a Holder 4 Lubricating device 5 Lubricant outlet openings 6 Supply line 7 Inner section 8 Outer section 9, 9a Inlet segment 10, 10a Inlet 11 Roll shell 12 End face 13 Pressure hose