FI121794B - Device for treating fiber suspension - Google Patents

Description

DEVICE FOR HANDLING THE CURRENT SUSPENSION

The present invention relates to a device for treating a fiber suspension. The device according to the invention is particularly well suited for sorting and / or precipitation of fiber suspensions 5 in the wood processing industry, i.e. situations where either fibers, liquid or both must be removed from the fiber suspensions. The device according to the invention can be well used e.g. paper machine reject treatment or branch separation after a pulp boiler butt, just to name a couple of preferred uses.

The starting point of this invention is the so-called. Stocker screws, previously treated e.g. U.S. Patent Nos. 3,947,314 and 4,160,722 and Fl Patent 89520. The prior art device is thus characterized in that the axis of the device is either vertical or slightly inclined, having a screw thread securing the lower end of the device to move the material to be processed, and 15 is surrounded by a screen surface through which the material flowing through is removed from the lower end of the device and the so-called. the reject material is removed from the upper end of the device. The device is often used in so-called. as a knife scrubber, i.e., the device aims to separate the fiber suspension from the branches and the corresponding larger solid bodies with the fibers and fiber flocs that travel with them and to accept them through the screen surface. During such acceptance, the fluid in the graft mass also passes through the screen surface, whereby the consistency of the reject mass is rapidly increased. The aim is to increase the consistency as much as possible, since the kneaded pulp removed from the appliance is usually returned to the soup.

Fig. 1 is a schematic axial sectional view of a prior art pulp processing apparatus 1. The Stocker ™ device consists on the outer sides of an outer jacket 10 consisting of the upper part 14 of the body, the central part of the body

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9 12, which may be either cylindrical or any other suitable shape, and the body

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° from the bottom 38. Frame-shaped upper part of the housing arranged at the upper end of the outer jacket 10 | 30 14 extends downwardly to form a reject material discharge chute 16.

co An actuator 18 is further mounted or otherwise arranged on the top of the body

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The lower end 38 is provided with a feed connection 20 for the material to be treated

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§ an outlet for accepting material 22. A solid is arranged inside the outer jacket 10

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a substantially cylindrical, or in some cases conical or otherwise 35 rotationally symmetrical, screen surface 24. Thus, there is 2 an elongate annular space 26 between the outer jacket 10 and the screen surface 24 into which the accumulating material accumulates after piercing the screen surface 24 is disposed on the inside of the screen cylinder 24. a threading member 30 acting as a transfer member so that together they form a screw 32, 5 for transferring upwardly the feed material from the joint 20, which rotates at a speed determined by the actuator 18 in a space 34 defined by the screening surface 24. to room 34.

More specifically, the lower body 38 of the body is partially cylindrical, having a sloping base 10 and a machined square top flange 42, a feed connection 20 and a scrap trap assembly 44. It also has a machined flange 46 for a combined screw dilution pipe 36 and lower bearing 56 for mounting and positioning and machined guard tube 48 for lower bearings 56.

The central body 12 of the body is square and its upper and lower flanges 50 and 42, respectively, are square and machined. The central portion is associated with said square machined accept shaft flange 22. The upper body portion 14 is associated with a lid 54 having a welded and machined housing for the upper bearing of the shaft 28.

20 The operating principle of the device is explained in the so-called. with reference to a knife cleaner. The material to be treated, in this case the fiber suspension, is fed from the unit 20 to the interior space 34 of the screen cylinder 24, where it is slowly moved upward by a screw 32. As it proceeds in space 34, fibers and liquid are separated from the suspension which fit through the openings of the screen surface 24 and are accepted into the space 26 where they exit through 22. The openings 25 of the screen surface 24 are secured by spraying the washing liquid from the openings on the surface ς of the hollow shaft towards the screen surface. The consistency of the suspension increases as the liquid is removed and

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^ having reached the upper end of the screen cylinder 24, the tendency is to have a mass without it? more loose liquid than fibers, but ready to be removed and

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° to be returned for example to the soup.

I 30 co Although the device described above is well-functioning in itself, it consists of several separate parts of σ> §, the manufacture of which requires e.g. precision machining. In addition to the device

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installation and maintenance require many different work stages due to the presence of several separate parts and are thus time consuming.

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It is an object of the present invention to provide a fiber suspension handling device as described above for sorting and / or precipitating the fiber suspension, which removes fibers, liquid or both and has an improved structure so that installation and maintenance is simpler and faster.

To achieve these objects, the present invention relates to a device for treating a fiber suspension comprising at least: - an outer jacket, - a solid screen drum arranged within, having a screen aperture of 10 apertures, - a screw rotatably arranged on the screen drum and bearing at their ends, - from the connection with the screen drum at its upper part through which the fraction remaining inside the screen surface is removed, and 15 - from the drive unit connected to the upper end of the shaft for rotating the shaft, and - from the feed connection to the processed fiber suspension. The apparatus is characterized in that the screen drum acts as a body for supporting the screw shaft drive unit and the bearing, thereby forming a subassembly of the fiber suspension handling device that can be moved out of the housing 20 or into the housing.

The central idea of the present invention is to integrate the lower bearing shaft of a screw-type fiber suspension handling device into an assembly formed by a screen drum, a screw and an actuator to provide a movable subassembly. In such a subassembly 25, the screening drum acts as a guide frame from which both the screw drive unit drive unit and the bearing are supported and guided. This allows you to achieve cost savings in machine manufacturing (less machining, fewer parts,

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9) and gain flexibility in other construction of the device, since the body of the device can be made as a plate.

The upper end of the screen drum, preferably at the top of the screen area, has flanges. The shell of the apparatus σ> § is formed by a vessel having at least a wall portion and a bottom. The upper portion g of the diaper container has a support facing the inner portion of the diaper, preferably a flange against which the screen drum and ci thus subassemble is mounted and on which the screen drum is supported by flanges at its upper part 35 when the subassembly according to the invention is inserted. According to one embodiment, there may also be a second support, preferably a flange, on the lower part of the shell container, at a distance from the bottom, on which the flange of the bottom edge of the screen drum rests. In the shell vessel wall, typically in the area of the screen surface of the screen drum, there is a discharge connection for the fraction passing through the screen surface, typically 5 acceptors. A feed connection for the fiber suspension to be processed in the device is connected to the lower portion of the screen drum.

The fiber suspension transfer member is a screw-like structure consisting of a continuous helical band or sector-like threaded pieces connected to a rotating shaft.

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The subassembly according to the invention, in which the screen drum, screw, screw shaft actuator and bearing are combined into one subassembly, can be lifted by means of a lifting device by simple operations since it relies only on the supports inside the jacket vessel. The screw axis is, of course, connected to an actuator which is preferably attached to the screen drum via a cover 15.

According to one embodiment, the subassembly is in an inclined position on a sheath having at least one inclined wall having an opening and closing wall portion through which the subassembly is movable and / or serviceable.

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According to one embodiment, the jacket is provided with at least two subassemblies connected in parallel with the fiber suspension to be treated.

According to one embodiment, the diaper space is divided by a partition structure into at least two different compartments, each having at least one subassembly, and the inlet connections of the compartments are connected to different fiber suspension sources.

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9 According to one embodiment, the compartments are the same size.

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o | According to one embodiment, the compartments are of different sizes and have different number of cd subassemblies. According to one embodiment, the compartments are of different sizes and have section 05 subassemblies of different sizes. According to one embodiment, section 05 of the first section is connected to the outlet of the fraction passing through the screen surface into the feed section of the second section.

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to deal with said verse in another title.

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According to one embodiment, one compartment serves as a knife washer and the other as a reject washer.

According to one embodiment, one department serves as one of the 5 sorting steps of the sorting process and another department serves as the next sorting step.

With regard to the position of the fiber suspension handling device during use, the device is in most cases positioned slightly upright, but fully upright devices may also be used. Thus, it is essential for the device that its axis direction 10 deviates substantially from the horizontal and is closer to the vertical direction. The screw is in a substantially upright position, either straight up or slightly inclined, preferably up to 45 degrees.

Preferably, the subassembly according to the invention also includes an axle holder which is attached to the bottom of the subassembly, i.e. to the bottom of the screen drum. The lower bearing of the screw shaft is supported by this holder, which may be conical. In one embodiment, the shaft holder forms the bottom of the screen drum.

The present invention will be described in more detail with reference to the accompanying drawings, in which: Figure 1 is a schematic axial sectional view of a prior art fiber suspension processing device that can be used as a knot or reject washer; Figure 2 is a side elevation view of a preferred embodiment of the invention; Fig. 4 is a side elevation view of a preferred embodiment, Fig. 4 illustrates a device according to the present invention,

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Fig. 5 shows a preferred embodiment of the device according to the invention in a side view, g Fig. 6 shows a cd in another preferred embodiment of the device according to the invention, 05; Fig. 7 shows a preferred embodiment of the device according to the invention;

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Figure 8 shows a side view of another preferred embodiment 35 of the device according to the invention.

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Fig. 2 illustrates a fiber suspension handling device 60 according to the invention consisting essentially of an outer jacket 62 which may be either cylindrical or any other suitable shape. A substantially substantially 5 cylindrical, or in some cases conical or otherwise rotationally symmetrical, screen drum 64 is provided inside the outer jacket 62 with a screen surface 72 for passing through the accept portion of the fiber suspension. The upper end of the screen drum 64 is formed by a housing-like upper part which does not have a screen surface but is a reject material removal 66, for example a trough. Further, a cover part 68 having a drive unit for rotating the shaft is attached or otherwise arranged on the upper part of the body of the device. The actuator 70 mainly comprises a reduction gear, a belt drive, a motor mount and an engine. An elongated annular space 74 remains between the outer jacket 62 and the screen surface 72, in which the absorbed material accumulates after piercing the screen surface 72. Inside the screen drum 64, an axle 76 is rotatably provided with threaded strands 78 acting as transferring members of the fiber suspension 15. a transfer screw 82 which rotates at the speed set by the actuator 70 in the space defined by the screen drum 74. The outer jacket also has a connector 84 for removing material that has passed through the screen surface, typically the accept.

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The perforated screen drum has machined flanges 86 and 88 at the top and bottom ends. The upper end of the screw shaft has a ball bearing 90 and the lower end of the screw comprises plain bearings 92.

The invention is characterized in that the screw 82, the screen drum 64, and the associated cover part 68 and drive unit units 70, together with the lower bearing 92 ^ of the screw shaft 76, form a sub-assembly of the fiber suspension handling device

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9 out of the diaper or as a unit in the diaper.

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o | The top and bottom of the screen drum, preferably the top and bottom of the screen surface 72, have flanges co 86 and 88. The apparatus casing 62 is preferably formed by a cylindrical container having

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Section wall and bottom. The top of the diaper has a support facing the inside of the diaper,

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Preferably a flange 94 against which the screen drum is mounted and on which the screen drum rests

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is supported by the flanges 86 at its upper part when the subassembly 35 of the invention is placed inside the jacket. In the lower part of the shell vessel, at a distance from the bottom 7, there is also a second support flange 96 on which the flange 88 of the bottom edge of the screen drum rests. In the wall of the mantle container, below the screen drum, is a feed connection 80 for a fiber suspension to be processed in the device. In this embodiment, the shell vessel forms a combined feed and accept vessel having feed and accept ports.

Preferably, the subassembly according to the invention also includes an shaft holder 98 which is connected to the bottom of the subassembly to the lower portion of the screen drum 64. In this embodiment, the shaft holder is a downwardly directed cone mounted against the lower flanges of the screen drum 10. The lower shaft 92 of the screw shaft is supported by this holder such that the shaft engages a downwardly directed apex of the cone.

Fig. 2 is a bottom view showing how the subassembly of the invention can be lifted out of the jacket container 102 by a lifting device 102, for example for maintenance operations.

The device operates in such a way that the material to be treated, in this case the fiber suspension, is fed from the joint 80 into the interior space 100 of the screen cylinder 64, where it is slowly moved upward by a screw 82. As it proceeds through space 100, fibers and fluid 20 separate from the openings in the screen surface 72 and accept into space 74, where they exit through 84. The opening of the apertures of the screen surface 72 can be ensured by spraying the washing liquid from the apertures (not shown) on the surface of the hollow shaft towards the screen surface. The consistency of the suspension increases as the fluid is discharged and upon reaching the upper end of the screen cylinder 64, a tendency is made for a fiber suspension ready to be removed for further use.

Fig. 3 shows another preferred embodiment of the device according to the invention.

The difference with the device of Fig. 2 is that the screen 62 'surrounding the screen drum. In the embodiment of Fig. 3c °, the shell vessel 62 'acts as an acceptor vessel having an accept outlet | 108. At the top of the jacket vessel are supports 94 'and 96', preferably flanges, on which the sub-assembly cd of the invention rests on a section 05 flange 86 'at the top of the screen surface 72'. In this case, the bottom section of the 05 assembly of the subassembly according to the invention forms the bottom 104 of the screen drum with a feed connection 80 'in the vicinity.

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for the fiber suspension to be treated. Particular to this embodiment is that the feed tube 106 35 is passed through the jacket vessel through its upper part 8

In the embodiment of Fig. 3, the sub-assembly according to the invention also includes an axle holder 98 'formed by a screen drum base 104. The lower shaft 92' of the screw shaft is supported by this holder such that the shaft engages the center portion of the base.

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Figure 3 illustrates one example of the flexibility provided by the subassembly of the invention in the overall structure of a fiber suspension handling device. The screen drum is surrounded by a jacket receptacle 62 'which acts as an acceptor. The subassembly according to the invention is, in a sense, "dependent" on the cover portion of the diaper container on which the upper flanges of the 10 screen drums rest. Through the cover portion of the jacketed vessel passes a fiber suspension feed tube which is connected to an inlet at the bottom of the screen drum. The diaper can also serve as an accept / storage tank for accept when the container is sized this way. The liquid surface 63 'in the shell vessel may extend to the side of the screen surface.

Figure 4 shows the structure of the device according to the invention in an inclined position. A subassembly formed by the screen drum 110, the screw 112, and the actuator 114 is provided on the sheath 116, which rests on the feet 122 of the device. The fiber suspension to be treated is introduced through 118 into the lower portion of the diaper and further into the screen drum. The mantle also has an accept outlet 120. The reflex is removed from the top of the 20 screen drums to one through 124. For removal from the diaper, the subassembly is secured to the lifting device 126. According to the invention, the wall portion of the diaper is constructed to include an opening and closing portion 128 through which the subassembly can be moved away and back. In an inclined construction, this cover 128 of the device body can be easily opened over a long distance, so that many other operations besides moving the subassembly are also possible, such as e.g.

^ cleaning of clogged screws is easy. Alternatively, the cover portion may also be formed by a fully removable wall portion of the sheath (not shown).

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o co ° Naturally openable and closable cover part of cover or removable cover part of cover may | 30 may also be in a device in which the jacket and subassembly are in an upright position.

Thu 05 § The subassembly according to the invention offers the possibility of flexible solutions in a 05 § fiber suspension handling device, for example, in terms of capacity or different process steps

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performance.

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Figure 5 illustrates a fiber suspension handling apparatus in which two subassemblies 140 of the invention are arranged in parallel in the same jacket container 142. The subassemblies are supported by their flanges 144 or the like on the inner wall of the diaper, such as flanges 146. At the bottom of the diaper 5 there is a feed space 148 and above it a space 150 for passing through the screen surface of the screen drum, such as an accept. In this embodiment, the aforementioned spaces 148 and 150 are separated by a lower support structure 146 of the subassemblies. A fiber suspension 152 is introduced into the sieve drums of the subassemblies, which is carried upward by the screws. The separated accept is removed through 154 and 10 retained within the screen drum through reject links 156. By arranging the subassemblies in the same jacket container in parallel, two or more can increase the capacity of the fiber suspension handling device in a simple manner. The maintenance and similar operations of the device are simple to perform when each of the subassemblies can be individually moved from the jacket.

In the embodiment of Figure 6, the two subassemblies 160 of the invention are arranged in the same jacket vessel 162 to form compartments 170 and 172, but each has its own separate supply and acceptance space. Separate spaces are formed by placing a partition 164 in the interior of the mantle container. A different treatable fiber suspension 176 can be introduced into the feed space 166 than the feed space 168 (arrow 20 180). The compartment 170 may be coupled and arranged so as to be suitable for branch separation and the second compartment 172 for washing the reject, respectively. According to another embodiment, the aforementioned compartments can be coupled and fitted to the different sorting steps of the sorting process, whereby, for example, one compartment 170 has, for example, a second stage of branch separation and another section 172 has a third stage of branching. Hereby, the screening surfaces 25 of the screening drums of the compartments may have different perforations, and the acceptance fraction from the sorting step where the coarser fraction is recovered is further processed in another section having a smaller screening surface. Then, the acceptance line 174 of the compartment 170 is connected to the compartment 168

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9 from feeder 180. In compartment 172, the accept is removed from feeder 178.

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o | Figure 7 shows a modification of the embodiment of Figure 6. Fig. 7 illustrates another two-compartment fiber suspension handling apparatus in which an inner wall 192 is provided with a partition 192 for forming compartments 194 and 196 in which σ> g subassemblies of the invention are placed. Fiber suspension processing equipment

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the treatment compartments do not have to be the same size, but depending on the larger capacity requirement 35, a larger number of subassemblies having 10 screen drums can be placed in one compartment than in another compartment. In Fig. 7, one compartment is provided with one subassembly 198 and another with two subassemblies 200. The screening surfaces 202 and 204 of the compartment screen drums may have different properties, such as perforation, depending on the fiber suspension or fiber suspension fraction treated in the compartment. In the second compartment, two subassemblies 200 are connected in parallel to increase capacity. The feeder and acceptor outlet of compartment 194 are indicated by arrows 212 and 210, respectively. Inlet 196 and acceptor outlet compartment 196 are marked with arrows 208 and 206, respectively.

Figure 8 shows another preferred embodiment of the invention.

The compartments 224 and 230 formed by the partition wall 222 of the fiber suspension handling device 220 are of different sizes, whereby the diaper vessel may also be asymmetric. The subassembly 226 of the larger compartment 230 is also larger than the subassembly 228 of the smaller compartment 228. In the embodiment of Figure 8, the smaller compartment 224 is lower than the larger compartment. The present invention thus provides a compact fiber suspension processing device that can perform even various process steps and space utilization is efficient. The device shown in Fig. 8 can be advantageously applied to branch washing and reject washing, or to performing various sorting steps, such as the 2nd branch separator and the third branch separator. The inlet connector of the compartment 224 and the outlet compound of the accept 20 are indicated by arrows 238 and 236, respectively. Inlet 230 and acceptor outlet 230 are indicated by arrows 234 and 232, respectively.

The device according to the invention can advantageously function as a kneader or reject scrubber at a pulp or paper mill or for performing various sorting steps. The most revolutionary difference with respect to the known structure is that in the new construction, the lower bearing of the screw shaft ^ attaches to a subassembly comprising a screen drum, a screw and a screw driver such as its gear and drive motor. This sub-assembly can be installed,

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9 position, service and lift as a whole. Precisely tolerated parts co-important for the operation of the device can be mounted against the flanges of the screen drum which | 30 are precision machined during the manufacture of a screen drum. The cd frame parts of the new construction can be manufactured with plate working tolerances, almost without machined surfaces.

σ> o co σ> § The operating principle of the device according to the invention in the process of treating the fiber suspension is C 1 similar to that of the known structure. The device may also include a scrap trap 35 to remove heavy impurities.

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The device of the invention provides many advantages to similar known fiber suspension handling devices. Especially with regard to the "body" of the device, manufacturing is considerably less expensive than the present construction: fewer parts, less material thickness 5 required, since the body does not have to be machined so that the upper and lower bearings are aligned on the body flanges.

It is possible to make various variations of the subassembly according to the invention as shown above, for example in Figures 2 and 3. In addition, Fig. 3 shows 10 exemplary subassemblies mounted on a type, whereby the feed tube of the fiber suspension to be treated is integrated.

The lifting height required for maintenance work above the unit can be reduced, especially if the unit is constructed with a slope. The subassembly allows for easy assembly of the device 15 even when the device is tilted.

The construction according to the invention allows different mounting methods while the main component or subassembly of the device remains unchanged.

The advantages of the device according to the invention also appear in the maintenance procedures. The parts essential to the operation of the device are more easily accessible than in known designs. It is easy to construct service hatches on plate parts. In an inclined construction, the "cover" of the body can be easily opened over a long distance, so that it is easy to clean a blocked screw, for example.

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Claims (13)

An apparatus for treating fiber suspension, comprising an outer jacket (62, 62 ', 116, 142, 162,190, 220), a fixed screen drum (64, 110) disposed therein, the screen surface of which (72, 72') is provided with apertures, a screw (82, 112) rotatably arranged within the screen drum and consisting of a fiber suspension transfer member (78) and a shaft (76), the ends of which are provided with bearings, 10. a tube (66, 66 ', 124, 156) which stays in communication with the screen drum in its upper part and through which a fraction remaining on the inside of the screen surface is removed, as well as a drive device unit (70, 114) coupled to the shaft (76) for rotation of the shaft (76). and a feed tube (80, 106, 118, 176, 180, 208, 212, 234, 238) for the fiber suspension to be treated and an outlet tube (84, 108, 120, 154, 174, 178, 206, 210, 232, 236) for the fraction which permeated the screen surface, characterized in that the screen drum (64, 110) acts as a body supporting screw the drive assembly unit (70) and bearing system (92) of the shaft (76), forming a subassembly of the fiber suspension processing device, which subassembly can be moved away from the manhole or into the manhole. Device according to Claim 1, characterized in that the outer manifold is constituted by a sheath vessel (62 '), the upper part of which is provided with a support (94', 96 ') directed against the inner part of the sheath, preferably a flange against which the sub-assembly is mounted and on which the sub-assembly is supported by the flanges (86 ') in the upper part of the screen drum 5. cv in CO 0 Apparatus according to claim 2, characterized in that the male member is a vessel (62) having a wall part and a bottom, and in the lower part of which, at a distance from the bottom, is also a second support (96). preferably a flange against which the flange (88) on the bottom edge of the screen drum rests. o co CD o o C \ l Device according to any of the preceding claims, characterized in that the part composition is in an inclined position within the male insert (116) which has at least one oblique wall with a wall part (128) which can be opened and closed, through which the wall part the part composition can be moved and / or entertained. 5 Device according to any of the preceding claims, characterized in that at least two part compositions (140) which are connected in parallel in relation to the fiber suspension (152) to be treated are arranged within men (142). Apparatus according to any one of claims 1 to 4, characterized in that the casing space (162, 190, 220) is divided into at least two different sections (170, 172; 194, 196; 224) by means of a partition structure (164, 192, 222). 230), each of which compartments have at least one subassembly (160, 198, 200, 226, 228), and the compartment feed pipes (176, 180, 208, 212, 234, 238) are coupled to 15 different sources of fiber suspension. Device according to claim 6, characterized in that the compartments (170, 172) are equal in size. Device according to claim 6, characterized in that the compartments (194, 196) are different in size and have different number of sub-compositions (198, 200). Device according to claim 6, characterized in that the compartments (224, 230) are different Large and have different Large sub-compositions (226, 228). 25 Device according to claim 6, characterized in that the outlet pipe (174) of the fraction which penetrated the screen surface of the first compartment (170) is coupled to the feed tube (180) of the second compartment (168) for treating said fraction in the second compartment. . CO ° 30 X Apparatus according to any of claims 6-10, characterized in that one co-section functions as a twig washer and the other as a reject washer. o CO σ> o o CM Device according to any of claims 6-10, characterized in that one compartment functions as a screen step in the screening process and a second compartment as a subsequent screen step. Device according to any of the preceding claims, characterized in that the sub-assembly comprises a holder (98, 98 ') for the screw shaft connected to the bottom edge of the screen drum (64). δ (M i CO o CO o X and CL CD O) o CD O) o o (M