Transverse disc of a centrifuge screw, and solid-bowl screw centrifuge

Abstract

The invention relates to a transverse disc (60) of a centrifuge screw (30) for stabilising a screw hub structure. According to the invention, at least one opening (70) is formed at least in some sections on at least 75% of all the imaginary circle lines (71) of the transverse disc (60) between the centre point (M) and the transverse disc circumference (72).

Description

[0001] The invention relates to a solid-jacket screw centrifuge with a centrifuge screw, according to claim 1.

[0002] Solid-jacket screw centrifuges are characterized by a drum with a closed or solid jacket. The drum is rotated at high speed, allowing a multiphase mixture inside to be separated into at least a heavy phase and a light phase. The heavy phase is typically a solid phase, which is conveyed out of the drum by a screw, i.e., a centrifuge screw. For this purpose, the screw is mounted so that it can rotate within the drum and has a helix. The helix is ​​arranged around a screw hub.

[0003] The screw helix travels along the inner surface of the drum, conveying the heavier phase material to an axial end of the drum. At the end of the drum, the heavier phase material is discharged, for example, from a discharge cone. The multiphase mixture to be clarified is therefore located between the inner surface of the drum and the screw hub.

[0004] In certain solid-wall screw centrifuges, a large pond depth is desirable, particularly for clarification reasons. However, the pond depth is limited by the diameter of the screw hub and the resulting buoyancy and sedimentation effects of the mixture or light phase being clarified.

[0005] The diameter of the screw hub cannot be reduced indefinitely, as the stiffness and stability of the centrifuge screw depend on the diameter of the screw hub.

[0006] It is known from the prior art to design screw hubs such that they are reduced with respect to the screw hub wall. Recesses can thus be formed between individual screw hub walls, see e.g. KR 101 943 944 B1.

[0007] However, it is necessary to design such worm hub constructions with appropriate transverse discs so that the worm hub is stabilized.

[0008] Based on the existing state of the art, the object of the present invention is to provide a transverse disk for a centrifuge screw for stabilizing a screw hub structure, which on the one hand sufficiently stabilizes the screw hub structure, and on the other hand is designed in such a way that liquid, i.e., the centrate in the solid-bowl screw centrifuge, can flow out unhindered. The transverse disk is to be designed in such a way that its stiffness is not impaired.

[0009] Furthermore, it is an object of the present invention to provide a further developed solid-jacket screw centrifuge which is further developed with regard to the transverse disk.

[0010] This problem is solved with regard to the solid-wall screw centrifuge by the subject matter of claim 1. The dependent claims include at least suitable embodiments and further developments.

[0011] The invention is based on a transverse disk of a centrifuge screw for stabilizing a screw hub structure, wherein at least 75% of all circular lines of the transverse disk extending from the center to the circumference have at least one opening, at least partially. The circular lines in question are all those that can be formed in the radial extent between the center and the circumference of the transverse disk.

[0012] Preferably, in the theoretical or imagined embodiment, the distance between the circles is only 5 mm, in particular 2 mm, in particular 1 mm, in particular 0.5 mm. In such a consideration of the circles, the distance between the circles is preferably equal.

[0013] A transverse disk of a centrifuge screw is understood to be such a disk, which is formed transversely to the longitudinal axis of the screw hub.

[0014] The transverse washer serves in particular to stabilize such a worm gear hub construction, which is based, for example, on a structure of several longitudinal rods. A transverse washer can also be referred to as a support washer.

[0015] Starting from the center point and extending towards the circumference of the transverse disk, the transverse disk has imaginary circular lines. At least 75% of all imaginary circular lines have an opening or a segment of an opening, at least partially.

[0016] In other words, at least one opening or at least a partial opening is formed in at least 75% of the total diameter range of the transverse disk, at least partially across the respective diameter. In other words, at least one opening or at least a partial opening is formed on at least 75% of all diameters of the transverse disk, at least partially across the respective diameter.

[0017] Such a design of openings across a large portion of the diameter of the transverse disk allows for good flow of the liquid or centrate in the area of ​​the screw hub structure. At the same time, such a transverse disk exhibits sufficient rigidity so that it continues to provide good stabilization of the screw hub structure.

[0018] In one embodiment of the invention, a diameter region of the transverse disk, which defines a central opening of the transverse disk, can in particular be designed without opening(s). Such an opening-free section can provide additional stability to the transverse disk.

[0019] In a particularly preferred embodiment of the invention, an opening or a section of an opening is formed at least partially on all imaginary circular lines of the transverse disk. In other words, it is particularly preferred that at least one opening or at least a partial section of an opening is formed over the entire diameter range of the transverse disk with respect to each diameter.

[0020] It is possible to construct the transverse disc in such a way that the liquid or centrate can flow out across the entire diameter range of the transverse disc.

[0021] Preferably, the openings of the transverse disk are designed such that these openings have different geometries and / or opening sizes and / or arrangement patterns.

[0022] The geometry of an opening refers to its shape. It is possible that the transverse disk has several openings with different geometries.

[0023] In other words, the opening size refers to the opening area. Liquid can flow through and / or out of the opening. It is possible for the openings to have different dimensions.

[0024] The arrangement pattern is understood to mean the arrangement of several openings, wherein at least two openings form an opening group, and wherein several opening groups can be arranged distributed across the transverse disk. Furthermore, it is possible for the transverse disk to have a group of openings that form several openings evenly distributed across the transverse disk. Preferably, a group of openings is formed from several similarly designed openings. Similar openings are understood to be openings that have the same geometry and the same cross-sectional area.

[0025] In one embodiment of the invention, the transverse disk has several openings that are cam-shaped, egg-shaped, or elliptical. Preferably, such openings are arranged in pairs. A pair of such openings thus forms an opening group. Several such opening groups can, in turn, be arranged evenly across the transverse disk.

[0026] A cam-shaped opening is understood to be an opening that essentially has the shape, particularly the cross-sectional shape, of a cam lobe on a camshaft. Specifically, such an opening has the shape of a steep cam. In other words, such an opening is formed from two circular segments whose centers of radius lie on a common axis of symmetry of the opening. The circular segments are, in turn, connected to each other segmentally by straight lines.

[0027] Furthermore, the openings can be egg-shaped or elliptical. In a particularly preferred embodiment of the invention, two such openings are arranged relative to each other to form an opening group.

[0028] In a particularly preferred embodiment of the invention, six openings are each cam-shaped, egg-shaped, or elliptical, with two openings forming an opening group. The three opening groups thus formed are arranged uniformly in the circumferential direction on the transverse disk.

[0029] The transverse disk according to the invention can furthermore have several openings starting from the circumference of the transverse disk, which are designed as recesses of the circumference of the transverse disk.

[0030] These recesses are preferably U-shaped.

[0031] Preferably, such recesses, in particular U-shaped recesses, are arranged in pairs. In a particularly preferred embodiment, the transverse disk has six such recesses, in particular six such U-shaped recesses. Two of the recesses form an opening group. The three opening groups thus formed are arranged uniformly in the circumferential direction on the transverse disk. In the circumferential direction, opening groups formed from U-shaped recesses preferably alternate with opening groups formed from cam-shaped openings.

[0032] Preferably, the U-shaped recesses in the direction of the center of the transverse disk have a length such that, in a radial extension from the center to the circumference of the transverse disk, the U-shaped recesses lie at least partially on congruent circular lines to the openings, which are cam-shaped.

[0033] In a further embodiment of the invention, the transverse disk has several openings which are circular in shape.

[0034] Preferably, the circular openings are arranged in pairs. In other words, two circular openings form a group of openings.

[0035] Preferably, six circular openings are formed. Six such openings can form three groups of circular openings. The opening groups are again arranged uniformly in the circumferential direction on the transverse disk.

[0036] Furthermore, it is possible that circular openings are arranged as individual openings, i.e., not grouped together. It is also possible that the transverse disk has several different configurations of circular openings. For example, a first type of circular opening may be arranged as groups of openings. A second type of circular opening may each be arranged as an individual opening.

[0037] In a further preferred embodiment of the invention, a group of openings consisting of circular openings and a group of openings consisting of U-shaped recesses are each formed in the same circular segment. The group of openings with circular openings is formed internally, i.e., internally in the direction of the center point.

[0038] In a preferred embodiment of the invention, the transverse disk is formed from six circular sectors, wherein three circular sectors each have opening groups with cam-shaped openings, and three circular sectors each have one opening group formed from U-shaped recesses and one opening group formed from circular openings. The circular sectors thus formed are arranged alternately.

[0039] The circumference of the transverse disk features recesses, preferably essentially semicircular, which are evenly distributed. These recesses, particularly the semicircular ones, serve to accommodate longitudinal rods that essentially form the worm gear hub structure.

[0040] In other words, the transverse disk preferably has a number of preferably essentially semicircular recesses on the circumference of the transverse disk that corresponds to the number of longitudinal bars which in turn form a screw hub of a solid shell screw centrifuge.

[0041] In one embodiment of the invention, twelve such semicircular recesses can be formed.

[0042] Furthermore, it is possible that the transverse disk has at least as many recesses on its circumference as correspond to the number of longitudinal bars that form the worm hub.

[0043] The number of recesses, preferably substantially semicircular, can be greater than the number of longitudinal bars. Therefore, a transverse disk can be provided that can serve as a transverse disk for several differently designed screw hubs. In other words, it is not necessary for the transverse disk to have only a number of recesses, preferably semicircular, that corresponds to the number of longitudinal bars. Rather, it is possible for individual recesses, for example every second semicircular one, to be designed as an additional fluid passage.

[0044] An opening may also be formed at the center of the transverse disk. This central opening may be circular with additional circular segment-like recesses, in particular three circular segment-like recesses. A circular segment-like recess is defined as a recess formed from a circular segment, where the circular segment is a portion of a circular area bounded by a circular arc and a circular chord.

[0045] Preferably, the circular segment-shaped recesses, in particular the three circular segment-shaped recesses, are formed uniformly in the circumferential direction around the circular shape of the central opening thus formed.

[0046] In a further embodiment of the invention, it is possible that the circular segment-like recesses, in particular the three circular segment-like recesses, are arranged in the transverse disk in such a way that in the circumferential direction, an opening group, which is formed from two circularly shaped openings, and a circular segment-like recess of the central opening alternate.

[0047] Preferably, three groups of openings, each consisting of two circular openings, and three circular segment-shaped recesses are formed. Preferably, at least one imaginary circular line of the transverse disk intersects both the circular segment-shaped recesses and the groups of openings, each consisting of two circular openings.

[0048] In a further embodiment of the invention, openings can also have a rhombus shape and / or a polygon shape and / or a pointed arch shape and / or a triangular or quadrilateral shape with at least partially curved sides.

[0049] The material of the transverse disk is formed between the individual openings of the transverse disk. This material is preferably made of metal.

[0050] In one possible embodiment of the invention, the openings are of such a size and arranged relative to one another that the material of the transverse disk is formed as ribs. The ribs can be straight and / or curved. Forming ribs creates a particularly advantageous ratio of opening sizes to the remaining material of the transverse disk.

[0051] The invention relates to a solid-wall screw centrifuge with a centrifuge screw which at least partially comprises a screw hub formed from longitudinal rods. According to the invention, at least one transverse disk according to the invention is arranged in the screw hub.

[0052] It is possible that several transverse disks according to the invention are formed in the worm hub. Furthermore, it is possible that the transverse disks arranged in a worm hub have different designs. It is possible that at least one of the formed transverse disks is a transverse disk according to the invention, whereas the other transverse disk(s) have a different design.

[0053] In a particularly preferred embodiment of the invention, the transverse disk forms an axial passage for a centrate produced in the solid-jacket screw centrifuge, independent of the pond depth formed in the drum of the solid-jacket screw centrifuge.

[0054] In other words, the use of the solid-wall screw centrifuge according to the invention, which has a transverse disk according to the invention, effectively prevents the solid material from accumulating in the drum in such a way that the openings or recesses formed as standard on the circumference of the transverse disk are blocked with solid material.

[0055] Rather, the liquid / centrate can flow freely due to the design of the transverse disc according to the invention. According to the invention, axial passage for the liquid / centrate is enabled at any pond depth without the centrifuge screw, in particular the screw formed from longitudinal rods, losing stability.

[0056] The solid shell screw centrifuge according to the invention can be either a 2-phase solid shell screw centrifuge or a 3-phase solid shell screw centrifuge.

[0057] An embodiment of the solution according to the invention is explained in more detail below with reference to the accompanying schematic drawings.

[0058] This shows: Fig. 1 shows a longitudinal section of a solid-wall screw centrifuge according to the invention, which has at least one transverse disk according to the invention; and Fig. 2 shows a representation of a transverse disk according to the invention.

[0059] In the following, the same reference numbers are used for identical and equivalent parts.

[0060] In Fig. 1 A solid-bowl screw centrifuge 10 is shown, extending essentially along a horizontal longitudinal axis 12. The solid-bowl screw centrifuge 10 has an outer housing 14 in which a drum 16 is rotatably mounted about the longitudinal axis 12. By rotating the drum 16 at high speed, a centrifugal force can be generated within it, by means of which a material to be clarified can be separated into a heavier and a lighter phase. For this purpose, the drum 16 is supported by a first drum bearing 18 and a second drum bearing 20. The solid-bowl screw centrifuge 10 shown is a two-phase solid-bowl screw centrifuge. However, the transverse disk according to the invention can also be implemented in a three-phase solid-bowl screw centrifuge.

[0061] The drum 16 has an inlet 22 for the material to be clarified, an outlet 24 for the heavy phase, and an outlet 26 for the light phase. A drive 28 is provided for rotating the drum 16. The outlet 26 acts as an overflow for the light phase located radially inside the drum, so that it automatically exits there when a predetermined level, the so-called pond depth 52, is reached in the drum 16.

[0062] To discharge the heavy phase located radially outside the drum 16, a centrifuge screw 30 is provided in the drum 16. The centrifuge screw 30 is rotated relative to the drum 16 by means of the drive 28. This causes the heavy phase material to be discharged radially inwards along a cone formed on the drum 16 and thus towards the outlet 24.

[0063] The centrifuge screw 30 is designed with a screw hub 32 extending longitudinally to the longitudinal axis 12, which is radially surrounded on the outside by a screw helix 34. The screw hub 32 thus serves to support the screw helix 34 in the radial direction, to transmit torque from the drive 28 to the screw helix 34, and in particular to absorb tensile and shear forces. The cylindrical longitudinal section 36 of the screw hub 32 is designed with a lattice structure 56.

[0064] The grid structure 56 is designed by means of twelve longitudinal bars 58, which are arranged at equal intervals around the circumference of the worm hub 32 in its longitudinal direction, i.e. parallel to the longitudinal axis 12.

[0065] The preferred number of longitudinal bars 58 is between 8 and 16, particularly between 10 and 14. The longitudinal bars 58 each form a radially outer contact surface for the screw helix 34 and are radially inner supported by transverse disks 60. The longitudinal bars 58 extend across the transverse disks 60, which are oriented transversely to the longitudinal axis 12 and thus form an inner support for the longitudinal bars 58.

[0066] Between each pair of transverse discs 60, there are between two and six diagonal struts 64.

[0067] In the conical longitudinal section 38, the screw hub 32 is formed with a cylindrical surface 44. The cylindrical surface 44 is essentially closed and is designed in particular by means of a sheet or a tube surface. The centrifuge screw 30 is rotatably mounted by means of a first screw bearing 40 and a second screw bearing 42.

[0068] The inlet area 48 is defined in particular by the inlet pipe 46. The inlet pipe 46 serves to feed the material to be clarified centrally into the interior of the screw hub 32 within the inlet area 48. Due to the screw hub 32, which is formed from longitudinal rods 58, the solid-jacketed screw centrifuge 10 has a large pond depth 52.

[0069] In Fig. 2 A transverse disk 60 according to the invention is shown enlarged.

[0070] It can be seen that a multitude of openings 70 are formed in the transverse disk 60. These openings 70 have different geometries, cross-sections, and arrangement patterns. The openings 70 are arranged, geometrically designed, and have such opening sizes that at least one opening 70 or a section of an opening 70 is formed at least partially on at least 75% of all circles 71 of the transverse disk 60 extending from the center M to the circumference 72.

[0071] In other words, the transverse disc 60, due to its formed openings 70, allows axial passage of the centrate at any pond depth 52 prevailing in the solid-wall screw centrifuge 10. At the same time, the stability of the transverse disc 60, and thus of the screw hub 32 or the centrifuge screw 30, is not negatively affected.

[0072] First, an opening 70 / 80 can be seen, which is formed at the center M of the transverse disk 60. This opening 80 has a circular shape 81 with additional circular segment-like recesses 82. In this case, three circular segment-like recesses 82 are formed. The circular segment-like recesses are evenly distributed around the circumference of the circular shape 81. In other words, the circular segment-like recesses 82 are each arranged at a 120° angle to one another.

[0073] Starting from the center point M in a radial direction, further openings 70 are arranged, which are designed as circular openings 73. These circular openings 73 have the smallest opening size compared to all other openings 70 of the transverse disk 60.

[0074] It can be seen that these circular openings 73 are arranged in pairs. Two circular openings 73 form an opening group 83. There are six circular openings 73 and thus three opening groups 83.

[0075] The opening groups 83 are again arranged uniformly in the direction of the circular arc on the transverse disk 60. In other words, the opening groups 83 are again arranged at 120° angles to each other. It can be seen that the opening groups 83 are arranged in relation to the central opening 80 such that each opening group 83 is positioned between two circular segment-like recesses 82. In other words, the opening groups 83 are again arranged at 120° angles to each other. It can be seen that along the exemplary circular line 71', both the openings 73 and the circular segment-like recesses 82 of the opening 80 are formed in sections.

[0076] In addition, three circular openings 73' are formed. These openings 73' have a smaller diameter than the circular openings 73. The three circular openings 73' are each radially internal to a recess 90. Furthermore, the circular openings 73' are radially extended to the center-to-center spacing of the circular openings 73 of the opening groups 83.

[0077] The transverse disk further has openings 70, which are cam-shaped. These cam-shaped openings 74 are in turn arranged in pairs.

[0078] It can be seen that six cam-shaped openings 74 are formed, with a total of three opening groups 84 being formed with respect to the cam-shaped openings 74. A cam-shaped opening 74 is understood to be an opening which, viewed from above, has the shape of a cam on a camshaft. It can be seen that the shape of the openings 74 corresponds to the shape of a steep cam. In order to form such a cam-shaped opening 74, the openings have two circular segments, namely the first circular segment 75 and the second circular segment 76. The second circular segment 76 is larger and has a larger radius than the first circular segment 75.

[0079] The two circular segments 75 and 76 are connected by means of connecting lines 77, so that the cam shape of the openings 74 is formed. It can be seen that all cam-shaped openings 74 are arranged such that the smaller circular segments or the smaller arc segments 75 point in the direction of the circumference of the transverse disk 72 and the second circular segments or the larger arc segments 76 point inwards towards the center point M.

[0080] The opening groups 84 are arranged such that, in the circumferential direction U, an opening group 84 and an opening group 83 are arranged alternately. Based on the exemplary circular line 71", it can be seen that on this circular line 71", both the circular openings 73 and the cam-shaped openings 74 are partially formed.

[0081] The transverse disk also has openings 70, which are designed as U-shaped recesses 78. A total of six such U-shaped recesses 78 are formed on the transverse disk 60.

[0082] Two of these recesses 78 are arranged in pairs to form an opening group 88. A total of three opening groups 88 are thus formed, which are evenly distributed across the transverse disk 60. The opening groups 88 are arranged at 120° intervals between each other.

[0083] Based on the exemplary circular lines 71‴ and 71*, it can be seen that on these circular lines 71‴ and 71* both the cam-shaped openings 74 and the U-shaped recesses 78 are formed at least partially.

[0084] The transverse disk 60 further has recesses 90 on its circumference 72. These recesses are essentially semicircular. The recesses 90 serve in particular to receive and fix longitudinal rods 58 of a worm gear hub 32.

[0085] In this case, twelve such recesses 90 are formed. Therefore, it is possible to form a worm gear hub 32 from twelve longitudinal bars 58. However, it is not necessary to accommodate a longitudinal bar in all recesses 90. In other words, if there are fewer than twelve longitudinal bars, for example, every second recess 90 can remain empty.

[0086] The transverse disk 60 is formed from alternately arranged circular sectors 94 and 95.

[0087] A first circular sector 94 comprises a circular segment-like recess 82 and an opening group 84 formed from cam-shaped openings 74. A second circular sector 95 comprises an opening group 83 formed from circular openings 73 and an opening group 88 formed from U-shaped recesses 78. Furthermore, a circular opening 73' is formed in each of the second circular sector 95.

[0088] Circular sectors 94 and 95 are arranged alternately relative to each other in the circumferential direction U. A total of three first circular sectors 94 and three second circular sectors 95 are formed.

[0089] Due to the differently designed openings 70 or 73, 74, 78 and 80, it is possible to form an axial passage for centrate produced in the solid shell screw centrifuge 10, regardless of the pond depth 52 formed in the drum 16 of the solid shell screw centrifuge 10. Reference symbol list

[0090] 10 Solid shell screw centrifuge 12 Longitudinal axis 14 Outer casing 16 Drum 18 First drum bearing 20 Second drum bearing 22 Inlet for material to be clarified 24 Outlet for heavy phase 26 Outlet for light phase 28 Drive 30 Centrifuge screw 32 Screw hub 34 Screw helix 36 Cylindrical longitudinal section 38 Conical longitudinal section 40 First screw bearing 42 Second screw bearing 44 Closed shell surface 46 Inlet pipe 48 Inlet area 52 Pond depth 56 Grid structure 58 Longitudinal bar 60 Transverse disc 64 Inclined brace 70 Opening 71, 71', 71", 71‴, 71* Circle line 72 Transverse disc circumference 73, 73' Circular opening 74 Cam-shaped Opening 75 first circular segment 76 second circular segment 77 connecting straight line 78 U-shaped recess 80 opening center 81 circular shape 82 circular segment-like recess 83 opening group 84 opening group 88 opening group 90 recess 94 first circular sector 95 second circular sector M center U circumferential direction

Claims

1. Solid bowl screw centrifuge (10) with a centrifuge screw (30), which comprises at least in some sections a screw hub (32) formed from longitudinal bars (58), wherein at least one transverse disk (60) for stabilizing a screw hub construction (56) is arranged in the screw hub (32), characterized in that at least one opening (70) is formed at least in some sections on at least 75% of all the imaginary circular lines (71) of the transverse disk (60) from the center point (M) to the transverse disk circumference (72), wherein recesses (90), which are arranged so as to be distributed evenly, are formed on the transverse disk circumference (72), wherein the recesses (90) serve to receive the longitudinal bars (58).

2. Solid bowl screw centrifuge (10) according to claim 1, characterized in that an opening (70) is formed at least in some sections on all imaginary circular lines (71) of the transverse disk (60).

3. Solid bowl screw centrifuge (10) according to claim 1 or 2, characterized in that the openings (70, 73, 75, 78, 80) of the transverse disk (60) have different geometries and / or opening sizes and / or arrangement patterns.

4. Solid bowl screw centrifuge (10) according to one of claims 1 to 3, characterized in that several openings (74) of the transverse disk (60) are formed in a cam-shaped or egg-shaped or elliptical manner and are in particular arranged in pairs.

5. Solid bowl screw centrifuge (10) according to one of the preceding claims, characterized in that starting at the transverse disk circumference (72), several openings (78) of the transverse disk (60) are formed as recesses, in particular as U-shaped recesses, which are in particular arranged in pairs.

6. Solid bowl screw centrifuge (10) according to one of the preceding claims, characterized in that several openings (73) of the transverse disk (60) are formed in a circular manner and are in particular arranged in pairs.

7. Solid bowl screw centrifuge (10) according to one of the preceding claims, characterized by an opening (80), which is formed in the center point (M) of the transverse disk (60) and which has a circular shape (81) additionally with further circular segment-like recesses (82), in particular three circular segment-like recesses (82).

8. Solid bowl screw centrifuge (10) according to one of the preceding claims 1 to 7, characterized in that independently of the pond depth (52) formed in the drum (16) of the solid bowl screw centrifuge (10), the transverse disk (60) forms an axial passage for a centrate formed in the solid bowl screw centrifuge (10).

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