Device and method for emptying a horizontal pulper

Abstract

The invention relates to a device and a method for completely emptying a horizontally extending treatment chamber. A rinsing device (35) is provided for emptying the treatment chamber (15). The rinsing device has a liquid supply (37) and at least one rinsing outlet (43) directed towards at least one longitudinal wall (18) of the treatment chamber (15). The rinsing liquid can be used to remove a layer of deposits that has formed between the working elements of the device and the wall.

Description

[0001] Device and method for emptying a horizontal pulper

[0002] The invention relates to a device and a method for emptying a horizontal pulper.

[0003] In conventional horizontal pulpers based on the drum principle, the water-added waste paper is shredded in the pulping zone by lifting, sliding, and falling, or by relative movement of the pulp components. Drums are generally operated with a continuous pulping process. This means that fiber suspension is continuously discharged at the drum outlet.

[0004] For example, EP 0 164 428 A1 discloses a horizontal pulping drum. The pulping drum for waste paper is rotatable about an approximately horizontal axis and is equipped with a closed peripheral wall that serves as a soaking drum for mixing water and waste paper, as well as for soaking the waste paper. A sorting drum with a perforated outer shell is connected to the pulping drum.

[0005] Waste paper treatment processes that utilize horizontal pulping drums offer the advantage of particularly gentle pulping, both for sensitive fiber types and for undesirable accompanying materials that can be sorted. However, fiber losses are high for fibers that are difficult to pulp compared to fiber pulping using a pulping trough. Losses in a pulping drum are high if the shear forces within the drum are insufficient to shred the raw material.

[0006] WO 2016 / 165860 discloses a horizontal pulper for dissolving HC pulps. The pulper is equipped with a U-shaped housing that is open at the top. Working elements connected to a shaft are arranged within the housing. The shaft is rotatably mounted, and the working elements act on the pulp. A gap is provided between the working elements and the U-shaped housing wall. The smallest radial gap is in the range of 5 cm to 50 cm. In this area, a surface layer can form, and it is not possible to completely empty the U-shaped housing through the mechanical conveying action of the working elements.

[0007] The object of the invention is to enable improved emptying of a horizontal pulper constructed in this way.

[0008] This object is achieved according to the invention by a device and a method according to the independent claims. Further advantageous embodiments of the present invention can be found in the subclaims.

[0009] By providing a flushing device for emptying the treatment chamber, the emptying of the treatment chamber can be assisted. The flushing device has a liquid supply and at least one flushing outlet directed toward at least one longitudinal wall of the treatment chamber. Liquid is introduced into the treatment chamber through the at least one flushing outlet. In the invention, the emptying is assisted by the supply of flushing water. The flushing water, on the one hand, causes dilution and, on the other hand, can exert force on a layer of deposits to cause them to be removed.

[0010] In a preferred embodiment, a plurality of flushing outlets are provided. This allows an entire section in the longitudinal direction to be exposed to flushing fluid, which advantageously reduces the time required for emptying. For even more targeted application, the flushing outlets can be designed as nozzles. As an advantageous further development, the nozzles can be pivotable.

[0011] In one embodiment, the flushing water is directed from above onto at least one of the longitudinal walls. This allows for the targeted removal of a layer of deposits, which can accelerate emptying.

[0012] In one embodiment, the flushing device is divided into several sections or can be divided into several sections. Actuable valves can also be provided for the subdivision. The sections can be supplied with flushing water at different times. Each section has at least one flushing outlet. Because the flushing device can only supply flushing fluid to a part of the device at a time, the flushing water supply required for this can be smaller. This has a beneficial effect on the required installation space. It also reduces the required pump power. This makes it possible to use existing pumps in the periphery of the device.

[0013] In one embodiment, it is provided that a pump provided for the removal of accepts is used for the application of rinsing water, wherein the liquid can be introduced by the pump, preferably for rinsing, at a pressure of 0.5 bar and / or can be flowed in at an initial flow velocity of at least 5 m / sec, preferably 10 m / sec.

[0014] Alternatively, the flushing device can be designed as a single unit with its own pump. Even in this case, it is advantageous if the pump's power can be kept low, which has a positive impact on costs. If the time required for emptying is paramount, providing a powerful pump and avoiding subdivision into sections may be preferable.

[0015] While the supplied rinsing liquid can flow through the normal stock outlet at the end of the pulping zone during the main phase of the rinsing process, additional, special openings are required for the actual emptying of the machine. In an advantageous embodiment, a closable lower outlet for draining suspension is provided in the lower wall section.

[0016] In a preferred embodiment, the lower outlet has a maximum diameter of 200 mm, preferably a maximum of 100 mm. This minimizes the risk of accumulations in the area of ​​the lower outlet, which could promote jamming.

[0017] In a preferred embodiment, at least one end outlet is provided in an end wall for draining the suspension from the treatment chamber. The suspension can be drained through this outlet. If this lateral outlet is located at the lowest point, the working chamber can be completely emptied through this outlet.

[0018] It has proven advantageous to provide a gap of preferably at least 1 cm, preferably 2 cm, as a lateral outlet between the shaft (23) and the end wall. A significant portion of the suspension can be discharged via this annular gap. There is no need for a further lateral outlet. Due to the selected dimension of the annular gap, it can be achieved that during normal operation with a significantly higher concentration of the suspension, no, or at least only a marginal portion, escapes through the narrow gap. The gap is also selected to be small enough that a maximum of suspension can escape into a downstream device, in this case the screening device. Due to the dimension of the gap, the escaped suspension cannot contain any heavy particles, which could cause damage to the screening device or downstream device.

[0019] It has proven advantageous to include the flushing device in a device for pulping fiber, especially waste paper. Especially in such devices, large gaps are provided between the working elements and the walls of the treatment chamber to prevent jamming caused by introduced, not yet dissolved material. However, this also carries the risk of a layer of deposits forming that cannot be removed from the treatment chamber during idle operation by the working elements.

[0020] The method according to the invention provides that a device in which a layer of deposits has formed on the wall of a treatment chamber during normal operation can be emptied by the method comprising the following steps. The layer of deposits is also removed.

[0021] The plan is for at least one section of the lower and / or longitudinal wall to be sprayed with liquid. The spraying serves the purpose of loosening deposits.

[0022] Spraying can be staggered in the different sections, preferably in sequential order. If spraying is carried out in sequential order, the amount of rinsing fluid entering the system is lower and can be discharged through the designated outlet openings.

[0023] Subsequently, deposits can be removed by switching the fluid supply to at least one other section of the work chamber and spraying the lower wall section of this section. This allows the entire treatment chamber to be freed of a layer of deposits, section by section, and the treatment chamber to be completely emptied. During and even during spraying, the suspension created by the rinsing fluid and the layer is removed. A lower outlet can be opened for this purpose. A side outlet can also be used to remove the suspension.

[0024] It can be provided that the shaft rotates with working elements so that the detached portion is discharged and / or conveyed towards the outlet. In a preferred embodiment, it is provided that, for complete emptying of a treatment chamber, the lower outlet is opened before the start of emptying. For this purpose, it may be necessary to open an outlet closed, for example, by a blind flange, so that a portion of the formed suspension is discharged via a lateral outlet (41, 48), and a lower outlet opening (39) is opened for the discharge of fiber suspension for complete emptying.

[0025] In one variant, a lateral connecting line to a downstream device is created, preferably installed before the start of the emptying process and removed again after the emptying process is complete. This allows a portion of the suspension formed by the rinsing liquid to be removed, and any fibers still contained in this suspension can be recovered as acceptable material.

[0026] The invention is explained below with reference to the figures. The figures show in detail:

[0027] Figure shows

[0028] Fig.1 : a schematic perspective view of an arrangement according to the invention for fiber processing fiber materials

[0029] Fig.2: Device according to the invention

[0030] Fig.3: a schematic perspective view of a device for fiber dissolution...

[0031] Fig. 4: Device with flushing device

[0032] Fig.5: Outlet shaft

[0033] Fig.6: Outlet flange

[0034] Fig.7: Sectional view of the device

[0035] Additional features, aspects, and advantages of the invention or its embodiments will become apparent from the detailed description in conjunction with the claims. Fig. 1 shows an arrangement 1 for processing fibrous materials, in particular for dissolving and sorting fibrous materials. In particular, the arrangement 1 is suitable for dissolving fibrous materials with high consistency in the HC range, and in particular for waste paper materials. The arrangement 1 comprises a dissolving device 11 and a sorting device 51. The dissolving device 11 is designed to dissolving fibrous material, and the sorting device 51 is designed for subsequently sorting the dissolved fibrous material. A heavy-parts separator 71 is arranged between the dissolving device 11 and the sorting device 51 for separating heavy parts such as wires, metal parts, plastic components, etc., which can be found in the fiber material, which is usually supplied in the form of bales. In addition, a feed 3 is provided for feeding the fiber material, particularly in the form of bales, into the dissolving device 11. In addition to the fiber material, dilution water is also added to dissolve the fiber material and form a fiber suspension. Further dilution can also be provided for treatment in the sorting device.

[0036] Both the pulping device and the sorting device 51 can be driven by a drive 5. A reject discharge opening 65 is provided at the end of the sorting device. A pump 15 is provided for discharging a fiber suspension separated as acceptable material.

[0037] Figure 2 shows a section of the arrangement from Figure 1. It shows the input area 3 for feeding waste paper from the rear. Below the input area, the shaft 23 is shown in the area of ​​the inlet into the housing 13 of the pulping device 11. Liquid feeds 37 of a rinsing device 35 are shown. These liquid feeds 37 are guided into the housing 13 of the pulping device 11. A sorting device 51 is connected to the pulping device. The shearing part separator 71 can also be seen in the background. Figure 3 shows an exemplary pulping device 11 with a housing 13. A shaft 23 is arranged in the housing 13. The shaft 23 is rotatably mounted about an axis of rotation parallel to a longitudinal axis of the housing 13. On the outer surface of the shaft 23, blade-like working elements 25 are arranged on the circumferential side and can be brought into engagement with the fiber material.A leading edge of the rotating blade-like working elements 25 can be inclined at an angle relative to a tangent applied to the circumference of the shaft 23, which is in particular less than 45° and preferably less than 30°. In particular, the working elements 19 can be disc-shaped or wing-shaped.

[0038] The housing 13 of the opening device 11 is designed in the form of a trough that is open at the top, U-shaped in cross-section and extends horizontally along shaft 23. In particular, it is provided that the trough of the housing 13 has, in its lower region, an inner wall that is partially circular in cross-section, in particular semicircular. The smallest radial distance 27 between the working elements 25 and an inner wall of the housing 13 of the opening device 11 is approximately 200 mm, preferably 300 mm, see Figure 7. This large radial distance 27, the radial direction being designated by 26, largely prevents the introduced, not yet opened fiber material from becoming trapped between the wall 16 of the treatment chamber 15 and the working elements 25. Figure 7 shows the radial region 24 swept over by the working elements 25.

[0039] In the embodiment shown here, the pulping device 11 is divided into an input zone 29 and a treatment zone 31. It can be provided that the diameter of the shaft 23 is larger in the input zone 29 than in the treatment zone 31. The pulped fiber material can be evaluated axially and / or laterally, in particular, and is continuously fed to the sorting module 50 after pulping. In particular, it can be provided that the pulped fiber material can be evaluated laterally in the region of upwardly moving working elements 25, so that the ejection is assisted by the moving working elements 25.

[0040] In addition, the opening device 11 can be equipped with a shredding device with various shredding elements. The shredding elements are intended to prevent foreign matter from wrapping around the shaft or from reaching a critical size that would impair the function of the working elements 25. The shredding elements are intended to shred torn fragments of a winder, and in particular, spinning parts such as cords, wires, plastic parts, and foreign matter in general. These shredded foreign matter are then removed from the fiber suspension by the heavy particle separator 71 and discharged. The shredding elements can be provided in both the input zone 29 and the treatment zone 31.

[0041] The rotating shaft 23 achieves a continuous pulping process, resulting in effective material utilization and uniform and stable processing of the fiber. In particular, speck-free pulping is possible for high-density fibers and raw materials that are difficult to pulp, which can be assisted if necessary by conducting the pulping at higher temperatures and / or adding chemicals. Typically, a fiber suspension with a pulp density of at least 4% by volume is achieved in the pulping device 11. The rotating working elements 25 enable the fiber to be thoroughly mixed and kneaded to form a fiber suspension, so that sufficiently high shear forces are exerted on the fiber components still to be separated in order to pulp the fiber in an energy-efficient manner.

[0042] The rinsing device 35 is described in more detail with reference to Figure 4. A first liquid supply 37 and a second liquid supply 37' are shown for supplying rinsing liquid. The rinsing device 35 shown here is divided into two sections 47 and 47'. The two sections 47, 47' can be supplied with rinsing liquid separately. This makes it possible to subject the sections to a rinsing process and thus to cleaning one after the other. This reduces the amount of rinsing liquid required at any one time, allowing the use of existing pumps. For example, a pump already used to transport the extracted accepts can be used. During a large part of the cleaning process, the accepts produced can be used for rinsing. This recirculation eliminates the need for pumping out. This means that the pump intended for accepts can be used.At the end of the cleaning process, filtrate can be added instead of the accepted material to further reduce the pulping density in the pulping tank.

[0043] The reference numerals marked with 'denote the components of the flushing device 35 of a second section 47'. Two sections are shown here as examples, but additional sections could also be provided.

[0044] The rinsing liquid supplied via the liquid supply 37 is fed via a distributor 38, 38' to a plurality of rinsing outlets 43, 43'. The rinsing outlets are arranged along the longitudinal direction 21 of the shaft 23. The rinsing outlets 43, 43' are directed parallel to or slightly obliquely toward the longitudinal wall 18. For good separation from the wall, the angle between the rinsing outlet and the longitudinal wall 18 in the direction of the circular segment-shaped wall section should not exceed 30°. Rinsing outlets can be provided on both sides. However, it may also be sufficient for rinsing liquid to flow in from one longitudinal side and for the flow to shoot the rinsing water up the wall to the opposite side.

[0045] By tangentially injecting flushing liquid, for example recirculated accepts, via downward-directed nozzles 45, 45' along a longitudinal wall 18 of the side wall of the container at a speed in the range of 5 m / sec, preferably at least 10 m / sec., the layer of deposits, also referred to as the edge layer, can be loosened from the wall. These loosened components can be flushed through a weir opening in the direction of the sorting device 51. After flushing has been stopped in the dissolving area, any suspension still contained therein that cannot flow over the weir can flow out through an annular gap 49 between the shaft and the end wall 19, see Figure 5. In the illustrated embodiment, an annular channel 48 is connected to the annular gap. The suspension can be discharged into the downstream sorting device 51 via the annular channel 48.The suspension produced during emptying has a lower concentration compared to normal operation. For example, the suspension produced during emptying can have a concentration that is at least 30% lower. It has proven particularly advantageous for the concentration of the suspension to be in the range of a maximum of 2.5%. This ensures that a portion of the resulting suspension is discharged via the annular gap 49 during emptying. Any remaining suspension can be drained off via a lower outlet 39. Preferably, the lower outlet 39 is not permanently present, but is formed with a flange 40. An outlet opening 39 with subsequent discharge can be mounted above this flange 40 for emptying. Since a portion is already discharged via the end wall 19, the lower outlet 39 can be small, e.g., with an opening diameter of a maximum of 100 mm.This can prevent or at least reduce the risk of deposits during normal operation.

[0046] Alternatively or in addition to the annular gap 49 and the lower outlet 39, an end-side lateral outlet 41 can be provided. Again, a flange 42 can be provided in the end face 19 so that the lateral outlet 41 can be mounted for emptying. A discharge via an inlet-side end wall 57 into a screening device 51 can be provided. Here, the dissolving device 11 and the screening device 51 are arranged adjacently, and thus only a short connecting piece 61 is required for discharging rinsing liquid into the screening device 51, see Figure 6. The rinsing liquid can flow via the connecting piece toward the sorting device 51. The lateral outlet 41 and also the lower outlet 39 are implemented here as closable outlets. Figure 7 shows a schematic section through a dissolving device. The area 24 swept over by the working elements is coaxial with the shaft 23.Gap 27 is clearly visible. This gap is designed to prevent the shaft from jamming. However, if no material is fed in, a layer of deposits remains. The flushing device 35 is provided to remove such a layer of deposits.

[0047] List of reference symbols

Claims

Patent claims 1. Device for fiber processing (9) with a horizontally extending treatment chamber (15) with lateral end walls (19) and with at least one lower circular segment-shaped wall section (17) and with a rotatable shaft (23) running in the longitudinal direction (21) of the treatment chamber (15), wherein the shaft (29) is provided with working elements (25) extending in the radial direction (26) and a gap (27) exists between the wall (16) and the working elements (25), characterized in that a rinsing device (35) with a liquid supply (37) with at least one rinsing outlet (43) directed towards at least one longitudinal wall (18) of the treatment chamber (15) is provided for emptying the treatment chamber (15).

2. Device according to claim 1, characterized in that a plurality of flushing outlets (43) are provided and these flushing outlets (43) are designed as nozzles (45).

3. Device according to one of the preceding claims, characterized in that the flushing water is directed from above onto at least one of the longitudinal walls (18), wherein the outlet opening of the at least one flushing outlet can be located below the shaft when viewed in the vertical direction.

4. Device according to one of the preceding claims, characterized in that the flushing device (35) has a plurality of sections or can be divided into a plurality of sections, wherein sections (47) each having at least one flushing outlet (43, 43') can be supplied with flushing water at separate times.

5. Device according to one of the preceding claims, characterized in that a pump (7) provided for the removal of acceptable material is used for the application of rinsing water, wherein the liquid is introduced by the pump (7) at a pressure of 0.5 bar, preferably for rinsing, and / or flows in at an initial flow rate of at least 5 m / sec, preferably 10 m / sec.

6. Device according to one of the preceding claims, characterized in that a closable lower outlet (39) for discharging suspension is provided in the lower wall section (17).

7. Device according to claim 6, characterized in that the lower outlet (39) has a maximum diameter of 200 mm, preferably of a maximum of 100 mm.

8. Device according to one of the preceding claims, in particular according to one of claims 6 or 7, wherein the treatment chamber (15) comprises an end wall (19) at the axial end, characterized in that at least one end outlet (41, 49) is provided in the end wall (19) for discharging the suspension from the treatment chamber (15).

9. Device according to one of the preceding claims, in particular according to one of claims 6 to 8, characterized in that the shaft (23) penetrates the end wall (19) of the treatment chamber (15), wherein between the shaft (23) and the end wall (19) a gap (49) of preferably at least 1 cm, preferably 2 cm is provided as a lateral outlet (41).

10. Device according to one of the preceding claims, characterized in that the device (9) is a device for dissolving (11) fibrous material, in particular waste paper.

11. Arrangement comprising a device (11) according to one of the preceding claims for dissolving fibrous material and a screening device (51) arranged adjacent to the end wall (19), characterized in that a connection (61, 48) for suspension exists or can be provided between the treatment space (15) of the dissolving device (11) and a working space of the screening device (51).

12. Arrangement according to claim 11, characterized in that the shaft (23) of the opening device (11) is connected to a shaft (67) of the sorting device (51) or are connected to one another, wherein an annular channel (48) around the shafts (23, 67) extends from the opening device (11) into the sorting device (51).

13. Method for emptying a device with a horizontally extending treatment chamber (15) and with radially extending working elements (25) that can be driven in rotation in the treatment chamber (15), wherein a radial gap (27) exists between the working elements (25) and the wall, comprising the following steps: -spraying at least one section (47) of the lower and / or longitudinal wall section (17, 18) with liquid, preferably at least temporarily with recirculated accept material, for loosening a layer of fiber deposited on the lower wall section (is the shaft stationary?) - subsequently switching the liquid supply (37) to at least one further section (47') of the working space and spraying the lower wall section (17) of this section - discharging the suspension formed by the liquid and the fiber layer via at least one outlet (39, 41, 48) - Discharge of any remaining amount of suspension via a lower outlet opening (39).

14. The method according to claim 13, characterized in that a part of the suspension formed is discharged via a lateral outlet (41, 48) and a lower outlet opening (39) for discharging fiber suspension is opened for complete emptying.

15. Method according to claim 13 or 14, characterized in that suspension discharged via the end wall (19) is fed into a working space of a subsequent device (51).

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