vibrating screen

Abstract

A vibrating screen (1) suitable for use in pharmaceutical and food processing includes: a screen support frame (10) having an inner periphery (11) and an outer periphery (12); a screen (20) for solid particles, extending horizontally within the screen support frame (10) and vertically supported by the screen support frame (10); one or more vibrating motors (30) disposed on the outer periphery (12) of the screen support frame (10) and generating vibration components in a direction (z) perpendicular to the screen (20); at least Two internal annular discs (14.1, 14.2, 14.3), each having an inner edge and an outer edge, wherein each of the at least two internal annular discs (14.1, 14.2, 14.3) is mounted to the inner periphery (11) of the screen support frame (10) via its outer edge, wherein the at least two internal annular discs (14.1, 14.2, 14.3) are spaced apart from each other in a parallel plane; an inner sleeve (17) is disposed within a sleeve support frame (10). The inner sleeve (17) is mounted to the inner edges of the two (14.2, 14.3) of the at least two internal annular discs, wherein the upper internal annular disc (14.2) and the inner sleeve (17) of the two internal annular discs have continuous surfaces, and the lower internal annular disc (14.3) of the two internal annular discs has an opening (18) facing the external environment. This device (1) is capable of handling high throughput and meets the highest hygiene standards.

Description

TECHNICAL FIELD

[0001] The present invention relates to a vibrating screen for separating solid particles, particularly for use in e.g. pharmaceutical and food processing industries. However, in general, it is also applicable to a wider range of applications such as mineral processing, dewatering, treatment of waste fluid streams, quarrying etc. BACKGROUND

[0002] A conventional vibrating screen generally comprises a screen carrying frame for carrying a screen for separating solid particles. The screen extends horizontally within the screen carrying frame and is supported vertically by the screen carrying frame.

[0003] In one vibrating screen, the vibration of the screen carrying frame is generally generated by two vibrating motors which are arranged opposite to each other on the outer periphery of the screen carrying frame. One of the advantages of vibrating motors is that these motors can be mounted directly on the screen carrying frame, thereby avoiding any additional transmission means, gear trains, couplings and other moving mechanical parts which require lubrication, which can contaminate the environment of the equipment, which can be a critical issue, particularly in the pharmaceutical and food processing industries.

[0004] The vibrating motors generate vibrations by the rotation of eccentric weights mounted on rotating shafts. By employing two counter-rotating vibrating motors, a directional vibration can be generated. The vibrating motors mounted on the screen carrying frame not only generate components in the vertical direction (i.e. upwards and downwards) but also components towards and away from each other. In particular, the forces towards and away from each other act on the screen carrying frame. That is, with each rotation of the vibrating motors, the radial forces tend to stretch and compress the screen carrying frame in the radial direction. This breathing can also be observed for a single vibrating motor as well as for a larger number of vibrating motors due to the inertial mass of the frame. The higher the required screening force in the vertical direction, the greater the forces acting in the radial direction on the screen carrying frame, which in turn can lead to a breathing of the screen carrying frame and material fatigue. Material fatigue can lead to the appearance of micro-cracks on the frame or welds.

[0005] By using thicker material or hollow profiles as the screen carrying frame, a high stability of the screen carrying frame can be achieved.

[0006] However, a heavier frame will require more powerful vibrating motors to generate the vertical screening force, which in turn leads to an increase in the radial forces. Ultimately, this will mean an extremely heavy duty equipment which will consume a lot of energy during operation.

[0007] Using hollow profiles can reduce weight, but it presents significant hygiene problems. Microcracks may appear during vibrating screen operation, but this doesn't necessarily affect safe operation. However, bacteria can multiply in these tiny cracks and invade the hollow spaces within the profiles. When cleaning the equipment, disinfectants cannot reach these hollow spaces, making it nearly impossible to remove bacteria once they have entered. In the worst-case scenario, bacteria such as Salmonella can spread throughout the entire production line, making it difficult to pinpoint their source. In pharmaceutical and food processing, the only option is often to discard the entire system.

[0008] In this context, the present invention aims to increase the material production capacity of vibrating screens while providing a lightweight structure and maintaining high hygiene and safety standards. Summary of the Invention

[0009] The vibrating screen of the present invention includes: a screen support frame having an inner circumference and an outer circumference; a screen for solid particles extending horizontally within the screen support frame and vertically supported by the screen support frame; one or more vibration motors disposed on the outer circumference of the screen support frame, generating vibration components in a direction perpendicular to the screen; at least two inner annular disks, each having an inner edge and an outer edge, wherein each of the at least two inner annular disks is mounted to the inner circumference of the screen support frame via its outer edge, wherein the at least two inner annular disks are spaced apart from each other in a parallel plane; and an inner sleeve disposed within a sleeve support frame and mounted on the inner edges of two of the at least two inner annular disks, wherein the upper inner annular disk and the inner sleeve have continuous surfaces, and the lower inner annular disk has an opening facing the external environment.

[0010] This results in a lightweight structure, allowing the device to be driven by a relatively small vibrating motor. The at least two internal annular discs and the inner sleeve reinforce the screen support frame in the space between the two vibrating motors, thereby reducing the risk of pushing and pulling of the screen support frame and the formation of microcracks.

[0011] Furthermore, the structure contains no enclosed hollow spaces. Therefore, it reliably prevents the formation of environments conducive to bacterial growth. All surfaces of the vibrating screen can be easily cleaned and disinfected. The openings in the bottommost internal annular disc ensure that cleaning and disinfecting agents can reach all surfaces of the internal annular disc and the inner sleeve. Therefore, this equipment meets the highest hygiene and safety standards.

[0012] In the first embodiment of the present invention, the screen support frame is basically cylindrical in shape, thereby avoiding corners and facilitating cleaning and disinfection.

[0013] In another embodiment of the invention, the outer diameter of the screen support frame is greater than 800 mm to allow for screening of high-volume products.

[0014] In another embodiment of the invention, the outer edges of at least two inner annular disks are welded to the inner periphery of the screen support frame to keep the overall structure very simple.

[0015] In addition, the inner sleeve can be welded to the inner edge of the two inner annular discs.

[0016] In another embodiment of the present invention, the at least two inner annular disks include a first, a second, and a third inner annular disk, wherein the inner edge diameter of the uppermost inner annular disk among the first, second, and third inner annular disks is larger than the inner edge diameter of the other two inner annular disks.

[0017] In another embodiment of the invention, a plurality of webs extend inwardly from the inner periphery of the screen support frame and perpendicular to the at least two inner annular disks, the webs being connected to the inner periphery of the screen support frame and at least one of the inner annular disks. This can further increase the radial stiffness of the screen support frame.

[0018] Specifically, at least two of the webs are arranged parallel to each other on the inner circumference, opposite to a vibrating motor on the outer circumference, to further increase the radial stiffness of the screen support frame, especially in the direction of the radial force generated by the vibrating motor.

[0019] In another embodiment of the invention, each vibrating motor has a rotation axis extending in a tangential plane on the outer periphery of the screen support frame, the tangential planes of the vibrating motors being parallel to each other. By tilting the rotation axis, the screening force can be adjusted as needed.

[0020] Preferably, the axis of rotation in the tangential plane is symmetrically inclined with respect to the vertical axis of the vibrating screen.

[0021] In another embodiment of the invention, the vibratory motor is mounted on the outer periphery of the screen support frame via a bracket, and the bracket is fixed to the outer periphery of the screen support frame. This simplifies the adjustment of the rotation axis direction of the vibratory motor.

[0022] In another embodiment of the invention, the vibrating screen includes a spring assembly that vertically supports the screen support frame on the machine base or substrate.

[0023] The vibrating screen may also include a cover that seals over the screen support frame. In this case, the screen is clamped between the upper edge of the screen support frame and the lower edge of the cover by a clamping device.

[0024] Additionally, the output hopper can be clamped between the upper edge of the screen and the screen support frame.

[0025] The present invention will now be described in more detail with reference to the accompanying drawings, wherein: Attached Figure Description

[0026] Figure 1 This is a three-dimensional view of a vibrating screen according to a possible embodiment of the present invention.

[0027] Figure 2 yes Figure 1 A side sectional view of the vibrating screen.

[0028] Figure 3 yes Figure 1 A top view of the vibrating screen.

[0029] Figure 4 yes Figure 1 A three-dimensional view of the screen support frame and vibrating motor of a vibrating screen.

[0030] Figure 5 yes Figure 3 A cross-sectional view of the structure shown.

[0031] Figures 1 to 5 An embodiment of the vibrating screen 1 of the present invention is illustrated. Detailed Implementation

[0032] The vibrating screen 1 includes a screen support frame 10, a screen 20 for separating solid particles, one or more vibrating motors 30, a cover 40, an output hopper 50, a clamping member 60, and a spring assembly 70.

[0033] The screen support frame 10 can be substantially cylindrical, having an inner circumference 11 and an outer circumference 12. It can be made of a metal sheet (preferably stainless steel) by forming a circular sleeve and welding the ends together.

[0034] However, non-circular shapes are also possible; for example, the screen support frame 10 can be rectangular.

[0035] A screen 20 for separating solid particles is vertically supported by a screen support frame 10 and extends horizontally (x, y) within the screen support frame 10. In the illustrated embodiment, the screen 20 may include a wire mesh 21 mounted on a perforated support plate 22, which is supported by the upper edge 13 of the screen support frame 10. The screen 20 can be removed from the screen support frame 10 and secured by clamping members 60 located at the outer periphery 12 of the screen support frame 10.

[0036] In the illustrated embodiment, the vibration force is generated by two vibration motors 30, which are arranged opposite each other on the outer periphery 12 of the screen support frame 10. However, the number of vibration motors 30 can be less, it can be a single vibration motor, or it can be more than two. The vibration motors 30 are arranged and configured to generate vibration components along the z-direction perpendicular to the screen 20. Each vibration motor 30 preferably includes an eccentric counterweight mounted on a rotation shaft. The vibration motors 30 operate in a counter-rotating manner to generate directional vibration, which includes a radial component in the xy-plane of the screen 20 in addition to the vertical component in the z-direction (i.e., upward and downward).

[0037] like Figure 4 As shown, the rotation axis A of each vibrating motor 30 extends within the tangential plane of the outer periphery 12 of the screen support frame 10, while the tangential planes of the two vibrating motors 30 are parallel to each other. By tilting the rotation axis A of the vibrating motor 30 relative to the vertical axis V of the vibrating screen 1, the radial and vertical components of the vibration force can be adjusted.

[0038] In the illustrated embodiment, the axis A in the tangential plane is symmetrically inclined relative to the vertical axis V of the vibrating screen 1, such that with each revolution of the vibrating motor 30, the vertical components add to each other, while the radial components cancel each other out.

[0039] As already mentioned, the vibratory motor 30 is arranged on the outer periphery 12 of the screen support frame 10. The vibratory motor 30 can be directly mounted to the outer periphery 12, or, as shown, mounted to the outer periphery 12 of the screen support frame 10 via brackets 31, for example, by welding. The vibratory motor 30 can be fixed to the brackets 31 with screws, and each bracket 31 has a mounting plate 32 for the vibratory motor 30. The mounting plate 32 is spaced apart from the outer periphery 12 of the screen support frame 10. Optionally, an adjustment mechanism can be provided between the vibratory motor 30 and the brackets 31 to facilitate the adjustment of the rotation axis A.

[0040] In order to reduce or prevent the screen support frame 20 from being pushed and pulled (i.e., elastic deformation) under the radial component force of the vibrating motor 30, the screen support frame 10 is provided with a specific internal reinforcement structure.

[0041] The reinforcing structure includes at least two inner annular discs. In the exemplary embodiment shown in the figures, the reinforcing structure includes first, second, and third inner annular discs 14.1, 14.2, and 14.3, each inner annular disc having inner edges 15.1, 15.2, and 15.3 and outer edges 16.1, 16.2, and 16.3. Each of the first, second, and third inner annular discs 14.1, 14.2, and 14.3 is fitted to the inner periphery 11 of the screen support frame 10 via its outer edges 16.1, 16.2, and 16.3, preferably by welding. These welds extend along the entire outer edges 16.1, 16.2, and 16.3, thereby preventing any gaps between the inner annular discs 14.1, 14.2, and 14.3 and the inner periphery 11.

[0042] The first, second, and third inner annular disks 14.1, 14.2, and 14.3 are spaced apart from each other in a parallel plane, preferably a horizontal plane. In the illustrated embodiment, the first inner annular disk 14.1 is disposed above and parallel to the second inner annular disk 14.2, and the second inner annular disk 14.2 is disposed above and parallel to the third inner annular disk 14.3.

[0043] The reinforcing structure also includes an inner sleeve 17, which is disposed within the screen support frame 10 and attached to the inner edges 15.2 and 15.3 of two of the first, second and third inner annular disks, where the two annular disks are the second and third inner annular disks 14.2 and 14.3.

[0044] The inner sleeve 17 is basically cylindrical and preferably connected to the inner edges 15.2 and 15.3 by annular welding.

[0045] like Figure 2 , 4 As shown in Figure 5, the upper inner annular disk 14.2 and the inner sleeve 17 of the two inner annular disks connecting the inner sleeve 17 have a continuous (unbroken) surface, i.e., without any openings; while the lower inner annular disk 14.3 has an opening 18 facing the external environment, preferably a downward opening. The two inner annular disks 14.2 and 14.3, the screen support frame 10, and the inner sleeve 17 form an annular channel 18a with a box-shaped cross-section, which, together with the single first inner annular disk 14.1, significantly increases the radial stiffness of the screen support frame 10.

[0046] However, in some cases, the first inner annular disk 14.1 can be omitted. In some other cases, the first inner annular disk 14.1 can be replaced by a second annular channel 18a with a box-shaped cross-section, thus resulting in a total of four inner annular disks.

[0047] For cleaning and disinfection purposes, the opening 18 is large enough to prevent bacterial growth in the circular channel 18a by rinsing it with a cleaning agent and / or disinfectant.

[0048] Optionally, multiple webs 19a, 19b may be disposed between the screen support frame 10 and the inner annular disks 14.1, 14.2, and 14.3. The webs 19a, 19b may extend inwardly from the inner periphery 11 of the screen support frame 10 and are perpendicular to the inner annular disks 14.1, 14.2, and 14.3. Specifically, the webs 19a, 19b may be connected (e.g., by welding) to the inner periphery 11 of the screen support frame 10 and to at least one of the inner annular disks 14.1, 14.2, and 14.3.

[0049] In the embodiment shown in the attached drawings, the upper web plate 19a is disposed on the uppermost side, i.e., the upper side of the first inner annular disk 14.1, and the lower web plate 19b is disposed on the lowermost side, i.e., the lower side of the third inner annular disk 14.3.

[0050] At least two of the webs 19a and 19b can be arranged parallel to each other on the inner perimeter 11, opposite to a vibrating motor 30 on the outer perimeter 12, thereby further increasing the radial stiffness of the screen support frame 10 in the direction of the radial force generated by the two vibrating motors 30.

[0051] The output hopper 50 is inserted vertically into the screen support frame 10 from the top and is clamped between the screen 20 and the upper edge 13 of the screen support frame 10. The output hopper 50 collects any material passing through the screen 20 and may have an output opening 51 for connecting, for example, a bag, container, etc. The output opening 51 may also lead to an output conveyor.

[0052] It should be noted that the diameter of the inner edge 15.1 of the uppermost inner annular disk in the first, second, and third inner annular disks is larger than the diameters of the inner edges 15.2 and 15.3 of the other two inner annular disks 14.2 and 14.3. The inner edges 15.1, 15.2, and 15.3 of the inner annular disks 14.1, 14.2, and 14.3 are cleared off from the outer wall of the output hopper 50.

[0053] The cover 40 sealably covers the screen support frame 10 and the screen 20. The cover has an inlet 41 for the product to be screened and at least one radial outlet 42 for solid materials that are too large to pass through the screen.

[0054] The screen 20 is clamped between the upper edge 13 of the screen support frame 20 and the lower edge 43 of the cover 40 by the clamping member 60.

[0055] In a preferred embodiment, the output hopper 50, screen 20, and cover 40 are then stacked on the upper edge 13 of the screen support frame 10 and are all secured together by a clamping member 60 configured to pull the cover 40 against the screen support frame 10.

[0056] The vibrating screen 1 is placed on the spring assembly 70 of the vertical support screen bearing frame 10.

[0057] In one specific embodiment, the vibrating screen 1 includes: a screen support frame 10 having an inner perimeter 11 and an outer perimeter 12; a screen 20 for separating solid particles, the screen 20 extending horizontally within the screen support frame 10 and vertically supported by the screen support frame 10; one or more vibration motors 30 disposed on the outer perimeter 12 of the screen support frame 10 and configured to generate a vibration component in a direction z perpendicular to the screen 20 and a vibration component in a radial direction xy of the screen 20; at least two inner annular disks 14.2, 14.3, each having an inner edge 15.2, 15.3 and an outer edge 16.2, 16.3; and an inner sleeve 17. Each inner annular disk 14.2, 14.3 is connected to the inner perimeter 11 of the screen support frame 10 via its outer edge 16.2, 16.3, and the two inner annular disks 14.2, 14.3 are spaced apart from each other in a parallel plane. The inner sleeve 17 is disposed within the screen support frame 10 and mounted on the inner edges 15.2 and 15.3 of the inner annular disks 14.2 and 14.3. The upper inner annular disk and inner sleeve 17 of the inner annular disks 14.2 and 14.3 are unbroken surfaces without any openings; while the lower inner annular disk 14.3 has an opening 18 facing the external environment, thereby defining an annular channel 18a together with the screen support frame 10, which is opened at the opening 18. Optionally, this specific embodiment can be further modified with respect to the features shown above, for example, by adding another inner annular disk 14.1 or changing the number of vibration motors 30.

[0058] The vibrating screen 1 of this embodiment meets the highest hygiene and safety standards for pharmaceutical and food processing. Specifically, the device 1 and its components can be cleaned and disinfected without causing biohazard. Cleaning agents and disinfectants can reliably reach all surfaces. Hidden hollow spaces that could only enter through tiny cracks, etc., where bacteria could multiply almost undisturbed, are completely avoided.

[0059] In addition, by using a vibrating motor 30 located on the outer periphery 12 of the screen support frame 10, the risk of lubricant contamination is minimized.

[0060] Due to the lightweight structure of the reinforced screen support frame 10, a relatively small vibration motor 30 can be used.

[0061] Radial forces are easily absorbed by the high radial stiffness of the reinforced screen support frame 10, making it possible to use large diameters of 800 mm or more with high throughput.

[0062] Therefore, the present invention provides an extremely simple solution to complex technical problems.

[0063] This invention has been described in detail with reference to exemplary embodiments and further modifications. However, the invention is not limited thereto, but includes all embodiments as defined by the claims. Specifically, even if not explicitly described above, technical features may be combined with each other, provided that this is technically feasible. Exemplary embodiments are intended to illustrate all aspects of the invention and are provided solely for the purpose of completeness of disclosure and enhanced understanding. However, this does not mean that all features described in combination must actually be combined with each other. Rather, it is explicitly stated herein that it is intended to cover all technically possible sub-combinations and permutations of the features in this disclosure, and their detailed description is omitted only for the sake of brevity.

Claims

1. A vibrating screen (1), comprising, A screen support frame (10) having an inner periphery (11) and an outer periphery (12), The screen (20) for solid particles extends horizontally within the screen support frame (10) and is vertically supported by the screen support frame (10). One or more vibration motors (30) are disposed on the outer periphery (12) of the screen support frame (10) and generate vibration components in a direction (z) perpendicular to the screen (20). At least two inner annular disks (14.1, 14.2, 14.3), each having an inner edge (15.1, 15.2, 15.3) and an outer edge (16.1, 16.2, 16.3), wherein, Each of the at least two inner annular discs (14.1, 14.2, 14.3) is mounted to the inner periphery (11) of the screen support frame (10) via its outer edge (16.1, 16.2, 16.3), wherein the at least two inner annular discs (14.1, 14.2, 14.3) are spaced apart from each other in a parallel plane. An inner sleeve (17) is disposed within the screen support frame (10) and mounted on the inner edges (15.2, 15.3) of the two (14.2, 14.3) of the at least two inner annular disks, wherein the upper inner annular disk (14.2) and the inner sleeve (17) of the two inner annular disks have continuous surfaces, and the lower inner annular disk (14.3) of the two inner annular disks has an opening (18) facing the external environment.

2. The vibrating screen (1) according to claim 1, characterized in that, The screen support frame (10) is basically cylindrical.

3. The vibrating screen (1) according to claim 1, characterized in that, The diameter of the outer periphery (12) of the screen support frame (10) is greater than 800 mm.

4. The vibrating screen (1) according to claim 1, characterized in that, The outer edges (16.1, 16.2, 16.3) of the at least two inner annular disks (14.1, 14.2, 14.3) are welded to the inner periphery (11) of the screen support frame (10).

5. The vibrating screen (1) according to claim 1, characterized in that, The inner sleeve (17) is welded to the inner edge (15.2, 15.3) of the two inner annular disks (14.2, 14.3).

6. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, The at least two inner annular disks include a first, a second, and a third inner annular disk. 14.1, 14.2, 14.3), wherein the diameter of the inner edge (15.1) of the uppermost inner annular disk (14.1) among the first, second and third inner annular disks is greater than the diameter of the inner edges (15.2, 15.3) of the other two inner annular disks (14.2, 14.3).

7. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, Multiple webs (19a, 19b) extend inward from the inner periphery (11) of the screen support frame (10) and are perpendicular to the at least two inner annular disks (14.1, 14.2, 14.3), the webs (19a, 19b) being connected to at least one of the inner periphery (11) of the screen support frame (10) and the inner annular disks (14.1, 14.2, 14.3).

8. The vibrating screen (1) according to claim 7, characterized in that, At least two of the webs (19a, 19b) are arranged parallel to each other on the inner periphery (11), opposite to a vibrating motor (30) on the outer periphery (12).

9. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, At least two vibration motors are provided, each vibration motor (30) having a rotation axis (A) extending in the tangent plane of the outer periphery (12) of the screen support frame (10), and the rotation axis (A) of the vibration motor (30) is parallel to each other in the tangent plane of the outer periphery (12) of the screen support frame (10).

10. The vibrating screen (1) according to claim 9, characterized in that, The axis of rotation (A) in the tangential plane is symmetrically inclined with respect to the vertical axis (V) of the vibrating screen (1).

11. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, The vibration motor (30) is mounted on the outer periphery (12) of the screen support frame (10) via a bracket (31), and the bracket is fixed on the outer periphery (12) of the screen support frame (10).

12. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, The spring assembly (70) vertically supports the screen support frame (10).

13. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, The cover (40) seals over the screen support frame (10), wherein the screen (20) is clamped to the upper edge (13) of the screen support frame (10) and the lower edge (43) of the cover (40) by means of the clamping member (60).

14. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, The output hopper (50) is clamped between the screen (20) and the upper edge (13) of the screen support frame (10).

15. The vibrating screen (1) according to any one of claims 1 to 5, characterized in that, Two vibrating motors (30) are arranged opposite each other on the outer periphery (12) of the screen support frame (10).

16. The vibrating screen (1) according to claim 6, characterized in that, Multiple webs (19a, 19b) extend inward from the inner periphery (11) of the screen support frame (10) and are perpendicular to the at least two inner annular disks (14.1, 14.2, 14.3), the webs (19a, 19b) being connected to at least one of the inner periphery (11) of the screen support frame (10) and the inner annular disks (14.1, 14.2, 14.3).

17. The vibrating screen (1) according to claim 8, characterized in that, At least two vibration motors are provided, each vibration motor (30) having a rotation axis (A) extending in the tangent plane of the outer periphery (12) of the screen support frame (10), and the rotation axis (A) of the vibration motor (30) is parallel to each other in the tangent plane of the outer periphery (12) of the screen support frame (10).

18. The vibrating screen (1) according to claim 17, characterized in that, The axis of rotation (A) in the tangential plane is symmetrically inclined with respect to the vertical axis (V) of the vibrating screen (1).

19. The vibrating screen (1) according to claim 18, characterized in that, The vibration motor (30) is mounted on the outer periphery (12) of the screen support frame (10) via a bracket (31), and the bracket is fixed on the outer periphery (12) of the screen support frame (10).

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