Disc filter

Abstract

The invention relates to a disc filter (10) comprising a cover (13) having walls (13A, 13C, 13D, 13E, 13F), the cover (13) comprising at least one inspection opening (14) in at least one wall (13A, 13C, 13D, 13E, 13F), the disc filter (10) comprising at least one inspection cover assembly (20), the inspection cover assembly (20) comprising a cover (21) and a security element (22), the inspection cover assembly (20) being configured in an openable manner to cover the inspection opening (14). The cover (21) is movable in a sliding manner to open the inspection opening (14) for visually inspecting the interior of the disc filter (10). The security element (22) is a see-through security element (22), and the security element (22) is located in an outer position with respect to an inspection cover (21) on a corresponding wall (13A, 13C, 13D, 13E, 13F) of a cover (13) of the disc filter (10).

Description

Technical Field

[0001] The present invention relates to a filter sector for filtering a fluid and solid mixture, in particular related to pulp and fiber web production. More specifically, the present invention relates to a disc filter. Background Art

[0002] As is known from the prior art, in a fiber web machine (especially in a paper machine and a board machine), the fiber web is produced and processed in an assembly formed by a plurality of devices arranged continuously on the production line. A typical production and processing line includes a forming section composed of a headbox and a forming unit, a pressing section, and subsequent drying sections and a reel. The production and processing line may also include other devices and parts for finishing the fiber web, such as a size press, a calender, a coating section. The production and processing line usually also includes at least one rewinder for forming a customer reel and a reel packaging device.

[0003] A fiber suspension containing recycled fibers and / or virgin fibers is processed before the headbox to be fed into the headbox for producing a fiber web. The processing system of the pulp suspension includes, for example, a pulping section, a deashing system, a detrashing system, a coarse filtration section, a centrifugal purification section, a fractionation section (screening section), a fine filtration system, a fiber thickening system (fiber concentration system), and a fiber refining system.

[0004] As is known from the prior art, different types of disc filters are used to separate liquids from a fiber suspension. A disc filter generally includes: a hood, inside which, in a vat, the disc filter includes a fiber suspension that contains a bath; a rotatable horizontal axis; and a plurality of filter discs spaced along the axis, which are supported on the axis or on a core assembly constructed on the axis.

[0005] Disc filters are well known in the art. Considering the operation of a fibrous web production line, the disc filter is one of the key factors according to the desired operation and is one of the most important pieces of equipment for producing the pulp supplied to the headbox of the fibrous web production line. If the disc filter does not operate as required, it may lead to significant losses in fibrous web production. During the operation of the disc filter, disturbances and / or malfunctions may occur in the operation of the disc filter, for example some filter discs may become blocked, or the fibres of the fibre suspension may accumulate on the inner surface of the tank, or the internal flow of the fibre suspension may not meet the requirements. Therefore, in order to check whether there are disturbances and / or malfunctions in the disc filter and in order to check whether any maintenance is required, in the current construction, the cover of the disc filter is provided with an openable inspection cover to allow visual inspection of the filter discs and the operation of the disc filter. The inspection cover is usually located on the longitudinal side of the cover and on the top of the cover. The inspection cover is usually configured as a hinged door which provides the openability of the inspection cover when inspection is required. At other times, the inspection cover is closed to prevent process steam and / or suspension from splashing outside the disc filter. Now, for safety reasons, the inspection cover assembly usually also includes a grille which is provided to cover the opening behind the inspection cover. Thus, the grille is located inside the cover surface relative to the inspection cover located on the cover surface. When the inspection cover is opened for inspection, the grille provides safety for the inspector and prevents the person performing the inspection from putting their hand or any other part of their body into the cover via the inspection opening. Thus, safety is provided, but as a result the grille provides a structure on which the fibres of the fibre suspension can easily adhere and accumulate, thus causing fibre accumulation. These fibre accumulations may cause disturbances during the operation of the disc filter and during the subsequent processing of the fibrous web production line and / or the equipment in front of it (for example when the fibre accumulation breaks off and falls into the fibre suspension). In particular, the fibre accumulation may provide an undesired substrate for bacterial growth. Especially in the case where the fibre suspension processed in the disc filter is to be used for producing food boards, even the ultimate health risk to the consumer has to be prevented. Summary of the Invention

[0006] An object of the present invention is to manufacture a disc filter in which the above problems are solved or at least minimized.

[0007] In particular, an object of the present invention is to provide a disc filter in which the contradiction between safety and the disadvantage of fibre accumulation adhering to the grille is eliminated or at least minimized.

[0008] In particular, an object of the present invention is to provide an improved disc filter which has a safe inspection cover but does not have the problem of fibre accumulation.

[0009] To achieve the above - mentioned objects and those objects that will become apparent hereinafter, the main features of the disk filter according to the present invention are described as follows. The advantageous aspects and features of the present invention are described as follows.

[0010] According to the present invention, a disk filter includes a housing having walls, the housing including at least one inspection opening in at least one of the walls, the disk filter including at least one inspection cover assembly including a cover and a safety element, the inspection cover assembly being configured to cover the inspection opening in an openable manner, wherein the cover is movable in a sliding movement to open the inspection opening for visual inspection of the interior of the disk filter, the safety element is a see - through safety element, and the safety element is located in an external position relative to the inspection cover on the corresponding wall of the housing of the disk filter.

[0011] According to an advantageous feature of the present invention, the housing of the disk filter includes at least one door on at least one wall of the housing, and the inspection opening and the corresponding inspection cover assembly are located on the door. The housing of the disk filter is provided with at least one door (usually several doors) to provide access for replacing the filter disks and / or the filtering sections of the filter disks, for example, in the case where one or more filter disks are damaged.

[0012] According to an advantageous feature of the present invention, the disk filter includes a plurality of inspection openings and corresponding inspection cover assemblies.

[0013] According to an advantageous feature of the present invention, the walls of the housing of the disk filter include a top wall and two side walls, and the top wall and the side walls include a plurality of inspection openings and corresponding inspection cover assemblies.

[0014] According to an advantageous feature of the present invention, the walls of the housing of the disk filter include a top wall and two side walls, the side walls include doors, and at least one door includes an inspection opening and a corresponding inspection cover assembly.

[0015] According to an advantageous feature of the present invention, the see - through safety element is made of a grille.

[0016] According to an advantageous feature of the present invention, to facilitate the sliding movement of the cover, the corresponding wall of the housing of the disk filter is provided with a sliding groove or track.

[0017] According to an advantageous feature of the present invention, to facilitate the sliding movement of the cover, the door is provided with a sliding groove or track.

[0018] According to an advantageous feature of the present invention, the wall includes an inspection opening, and the inspection opening is provided with a recess for the closed position of the cover of the inspection cover assembly.

[0019] According to an advantageous feature of the present invention, a maintenance platform is provided around the housing of the disk filter (and / or on top of the housing of the disk filter).

[0020] The term "fiber suspension" refers to a liquid and a suspension that contains at least fibers and a liquid, as well as other possible components. Fibers refer to recycled cellulose fibers and / or newly produced cellulose fibers (i.e., virgin cellulose fibers). In this specification and the claims, terms such as "top", "bottom", "side", etc. should be interpreted considering the disc filter in its normal operating position.

[0021] With the disc filter according to the present invention and its advantageous features, many advantages are achieved: The inspection cover assembly provides safety for the inspector and eliminates or at least minimizes the adhesion and accumulation of fibers within the inspection cover assembly, thereby preventing bacterial growth within the disc filter, providing safe production of food plates, and thus providing consumer safety. The inspection cover assembly is simple and unique.

[0022] The exemplary embodiments of the present invention presented in this patent application should not be construed as limiting the applicability of the appended claims. The verb "comprising" and its derivatives are used in this patent application as open-ended limitations that do not exclude the presence of features not mentioned. Unless otherwise explicitly stated, the features described below can be freely combined with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] However, when read in conjunction with the drawings, various aspects of the present invention, as well as its additional objectives and advantages, will be better understood from the following description of some example embodiments. And hereinafter, the present invention will be described in more detail with reference to the drawings, in which:

[0024] Figure 1 An advantageous example of the disc filter is schematically shown in an external view, and

[0025] Figures 2A - 2B An advantageous example of the inspection cover assembly of the disc filter according to the present invention is very schematically shown. DETAILED DESCRIPTION

[0026] During the course of this specification, similar numbers and symbols will be used to identify similar elements according to the different views showing the present invention. For the sake of clarity, some repeated reference numerals may be omitted in the figures.

[0027] In Figure 1In FIG. [not specified], a disk filter 10 is shown as seen from the outside. The disk filter 10 includes: a housing 13. Inside the housing 13, within the tub formed by the housing 13, the disk filter 10 includes a fiber suspension that contains a bath; a horizontal axis; and a plurality of filter disks that are spaced apart along the axis and are supported on the axis. The housing 13 has a cylindrical shape with two longitudinal sidewalls 13C, 13D, as well as a top wall 13A and a bottom structure 13B. The housing 13 also has end walls 13E, 13F that enclose the internal space of the disk filter 10. Around the housing 13 of the disk filter 10 and on top of the housing 13 of the disk filter 10, maintenance platforms 11, 12 are provided to provide easy access for operators and / or maintenance personnel to the disk filter 10. The disk filter 10 includes at least an openable and normally lockable door 15 located on the longitudinal side of the disk filter 10 to provide access to the interior of the disk filter 10 during maintenance interruptions, such as when one or more of the filter disks are damaged, for replacing the filter disks and / or the filtering sections of the filter disks.

[0028] The door 15 and / or the walls 13A, 13C, 13D, 13E, 13F of the disk filter 10 (usually the top wall 13A and the sidewalls 13C, 13D) have inspection openings 14 with inspection cover assemblies 20 for operators and / or maintenance personnel to inspect for any interference and / or malfunctions during the operation of the disk filter.

[0029] In Figures 2A - 2B a preferred example of the inspection cover assembly 20 for covering the inspection opening 14 located on the door 15 of the disk filter 10 is shown in more detail ( Figure 1 ). The inspection cover assembly 20 can also be located on any of the walls 13A, 13C, 13D, 13E, 13F of the housing 13 of the disk filter 10 (usually on the top wall 13A and the sidewalls 13C, 13D). Generally, as Figure 1 shown, several inspection cover assemblies 20 are located on the door 15 (the door is located on the longitudinal side of the housing 13 of the disk filter 10) and on the top wall 13A of the housing 13 of the disk filter 10. The inspection cover assembly 20 includes a slidable cover 21 to expose the inspection opening 14, thus providing the possibility of visual inspection. Therefore, the cover 21 opens in a sliding manner. In Figure 1 the example of Figures 2A - 2B , the cover 21 opens by sliding downward, but considering the space requirements and the positioning of the inspection cover assembly 20, the cover 21 can also slide upward or laterally as needed. In Figure 2A the sliding cover 21 is in the closed position, and in Figure 2BThe middle sliding cover 21 is in the open position. Thus, the cover 21 slides between the closed position and the open position (and vice versa), and can also stop at a position between the closed position and the open position. For the sliding movement of the cover, the corresponding walls 13A, 13C, 13D, 13E, 13F of the cover 13 of the disk filter 10 or the door 15 may be provided with sliding grooves or tracks. In addition, the inspection opening 14 in the corresponding walls 13A, 13C, 13D, 13E, 13F of the cover 13 of the disk filter 10 or the door 15 may be provided with a recess for inspecting the closed position of the cover 21 of the cover assembly 20 to position the cover 21 tightly to close the inspection opening 14. The cover 21 may also include a handle 23 to facilitate opening and closing of the cover 21.

[0030] The inspection cover assembly 20 further includes a transparent safety element 22, which provides safety for the inspector to prevent the person performing the inspection from putting their hand or any other part of the body into the cover 13 of the disk filter 10 through the inspection opening 14 when the cover 21 is in the open position for inspection. In the inspection cover assembly 20, in the closed position of the cover 21, the safety element 22 is located in front of the cover 21. Thus, in the inspection cover assembly 20, in the position where the inspection cover assembly 20 is located on the door or on the walls 13A, 13C, 13D, 13E, 13F of the cover 13 of the disk filter 10, the sliding cover 21 is first positioned from the inside of the cover 13, and then the safety element 22 is positioned from the outside of the cover. This also provides an additional distance between the safety element 22 and the rotating disk of the disk filter. The safety element 22 may be made of any transparent material, transparent glass material, or transparent plastic material, or transparent composite material or grid-type material. Preferably, the safety element 22 is a grid, more preferably a metal grid, such as Figures 2A - 2BAs shown. This further provides that occasionally when the interior of the disk filter 10 needs to be cleaned, the hose can pass through the grid holes of the safety element grid to supply the cleaning fluid to the interior of the cover 13 of the disk filter 10. The inspection cover assembly 20 according to the present invention provides openability for visually inspecting for interference and / or faults in the disk filter 10 and for checking whether any maintenance is required. The inspection cover 21 is configured as a slidable cover 21, which provides the openability of the inspection cover 21 when inspection is needed. During other operating times, the inspection cover 21 is closed to prevent process steam and / or suspension from splashing outside the disk filter 10 and onto the safety element 22. For safety reasons, the inspection cover assembly further includes a safety element 22 (advantageously a safety element grid 22), which is provided to cover the inspection opening 14 and is located in front of the inspection cover 21 (i.e., the outer position as seen from the inspection cover 21). When the inspection cover 21 is opened for inspection, the safety element 22 (advantageously a safety element grid 22) provides safety for the inspector, preventing the person performing the inspection from putting their hand or any other part of their body into the cover 13 via the inspection opening 14. Thus, safety is provided. The safety element 22 (advantageously a safety element grid 22) located in front of the inspection cover 21 (i.e., the outer position as seen from the inspection cover 21) prevents any fiber attachment and accumulation of the fiber suspension and the formation of fiber accumulation on the safety element 22. Thus, the operation of the disk filter 10 and subsequent processing in the fiber web production line and / or the equipment preceding it are free from interfering fiber accumulation. In particular, the substrate for bacterial growth is avoided, the safe production of food boards is provided, and further health risks to consumers are prevented.

[0031] In the foregoing description, although some functions have been described with reference to certain features, these functions may be performed by other features, whether or not described. Although some features have been described with reference to certain embodiments or examples, these features may also be present in other embodiments or examples (whether or not described). The present invention has been described above with reference to some advantageous examples, but the present invention is not limited to these examples. As defined by the following claims, many modifications and changes can be made within the present invention.

Claims

1. A disc filter, the disc filter (10) comprising a cover (13), the cover (13) having walls (13A, 13C, 13D, 13E, 13F), the cover (13) comprising at least one inspection opening (14) located in at least one of the walls (13A, 13C, 13D, 13E, 13F), the disc filter (10) comprising at least one inspection cover assembly (20), the inspection cover assembly (20) comprising a cover (21) and a safety element (22), the inspection cover assembly (20) being configured to cover the inspection opening (14) in an openable manner, characterized in that The cover (21) is movable in a sliding manner to open the inspection opening (14) for visual inspection of the interior of the disc filter (10), the safety element (22) is a see-through safety element, and the safety element (22) is located in an outer position relative to the cover (21) on the corresponding wall (13A, 13C, 13D, 13E, 13F) of the cover (13) of the disc filter (10).

2. The disc filter according to claim 1, characterized in that The housing (13) of the disc filter (10) comprises at least one door (15) located on at least one of the walls (13A, 13C, 13D, 13E, 13F) of the housing (13), and the inspection opening (14) and the corresponding inspection cover assembly (20) are located on the door (15).

3. The disc filter according to claim 1 or 2, characterized in that: The disc filter (10) comprises a plurality of inspection openings (14) and corresponding inspection cover assemblies (20).

4. Disc filter according to any one of the preceding claims, characterized in that The walls (13A, 13C, 13D, 13E, 13F) of the cover (13) of the disc filter (10) include a top wall (13A) and two side walls (13C, 13D), and the top wall (13A) and the side walls (13C, 13D) include a plurality of inspection openings (14) and corresponding inspection cover assemblies (20).

5. Disc filter according to any one of the preceding claims, characterized in that The walls (13A, 13C, 13D, 13E, 13F) of the cover (13) of the disc filter (10) include a top wall (13A) and two side walls (13C, 13D), the side walls (13C, 13D) including doors (15), and at least one of the doors (15) includes an inspection opening (14) and a corresponding inspection cover assembly (20).

6. Disc filter according to any one of the preceding claims, characterized in that The see-through security element is made of a grid.

7. Disc filter according to any one of the preceding claims, characterized in that For the sliding movement of the cover (21), the corresponding walls (13A, 13C, 13D, 13E, 13F) of the housing (13) of the disc filter (10) are provided with sliding grooves or tracks.

8. The disc filter according to any one of claims 2 to 7, characterized in that: For the sliding movement of the cover (21), the door (15) is provided with a sliding groove or track.

9. Disc filter according to any one of the preceding claims, characterized in that The wall (13A, 13C, 13D, 13E, 13F) including the inspection opening (14) is provided with a recess for inspecting the closed position of the cover (21) of the cover assembly (20).

10. Disc filter according to any one of the preceding claims, characterized in that A maintenance platform (11, 12) is provided around the cover (13) of the disc filter (10) and / or on top of the cover (13) of the disc filter (10).

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