Mixing tool for an industrial mixer, mixer and method

Abstract

The invention relates to a mixing tool (1) for an industrial mixer (18), comprising a holder (2) and a bolt (3) which is held by the holder (2) and which protrudes relative to the holder (2) for mixing. The invention also relates to a method for repairing a mixing tool (1) of a mixer (18) damaged by wear, wherein a worn bolt (3) is exchanged for a new bolt (3), but an arm (4) of the mixing tool (1) is not exchanged.

Description

[0001] Gebrüder Lödige Maschinenbau GmbH

[0002] G70710WG

[0003] Mixing tool for an industrial mixer, mixer and process

[0004] Description

[0005] The invention relates to a mixing tool for an industrial mixer, a mixer and a method.

[0006] An industrial mixer is a machine used in industrial processes to blend, granulate, homogenize, or emulsify various materials. Such mixers are used in numerous industries, including the chemical, food, pharmaceutical, construction, steel, and plastics industries.

[0007] An industrial mixer can consist of a drum and a shaft inside the drum. The shaft may pass through an end wall of the drum so that it can be driven from the outside. Mixing tools can be attached to the shaft. These tools may be made of metal. A protective coating may be present on the surface of the mixing tools to prevent wear. If such a protective coating wears out, the mixing tool must be repaired or replaced.

[0008] The purpose of the invention is to minimize the technical effort associated with wear and tear.

[0009] To solve the problem, a mixing tool can comprise the features of the first claim. A dependent claim relates to a mixer with the mixing tool. Another dependent claim relates to a method.

[0010] To solve the problem, a mixing tool for an industrial mixer can include a holder. The holder can hold the mixing tool body. The body can protrude from the holder for mixing. In case of wear, it may be sufficient to replace only the body. The body can be held interchangeably by the holder. The body can then be removed from the holder without damage. A new, unworn body can then be inserted into the holder and held in place.

[0011] The body, or at least a surface of the body, can be made of a material that is more wear-resistant than another material of the mounting. For example, another material might be steel, particularly a tough steel. The body, or at least a surface of the body, can then be made of a material that is more wear-resistant than steel. The surface of the body can, for example, be made entirely or predominantly of a ceramic.

[0012] The body can be a bolt. The body, for example a bolt, can form one end of the mixing tool. However, other shapes are also possible. For example, a body can be shaped like a plate.

[0013] An arm of the mixing tool can form one end of the mixing tool. The holder can be attached to the arm. The holder can project laterally from the arm. The holder can project obliquely from the arm or from a section of the arm. The holder can be twisted relative to a main surface of the arm. The holder can be detachably connected to the arm. The holder can be connected to the arm by at least one screw. The arm can include a wear-resistant protective layer on its surface. The protective layer can be at least 1 mm or at least 2 mm thick. The protective layer can be no thicker than 5 mm or no thicker than 4 mm. The protective layer can consist of a ceramic. The protective layer can consist of a carbide. In particular, the protective layer consists of tungsten carbide. Alternatively, the protective layer can consist of chromium carbide. The protective layer can consist of an oxide.Examples of possible oxides are aluminum oxide, zirconium oxide, chromium oxide or titanium oxide.

[0014] The arm may include a surface area without a protective coating. This unprotected surface area may be present at the end of the arm where the bracket is attached. A cover for at least one screw may be present on this unprotected surface area. The cover may be welded to the unprotected surface area.

[0015] The body can be held detachably from the bracket. The body can be fixed by a screw.

[0016] The bracket, arm and / or body can consist at least predominantly of metal, such as steel, especially tough steel.

[0017] A surface of the body can consist of tungsten carbide. The body can consist entirely of tungsten carbide.

[0018] A multiple body can be held by the bracket. Multiple bolts can be present as bodies, arranged, for example, parallel to each other. Bodies can be arranged at the same height. Bodies can be equidistant from each other. Bodies can be identical.

[0019] The distance between two adjacent bolts can be greater than the diameter of each bolt.

[0020] The length of a bolt projecting from the bracket can be greater than its diameter.

[0021] A body, such as a bolt, can project at least 4 cm or at least 5 cm from the mounting. A body, such as a bolt, can be at least 5 cm, at least 10 cm, or at least 15 cm long. The maximum thickness of a body can be at least 2 cm or at least 3 cm. The maximum thickness of a body cannot exceed 6 cm or 5 cm. The maximum diameter of a bolt can be at least 2 cm or at least 3 cm. The maximum diameter of a bolt cannot exceed 6 cm or 5 cm.

[0022] A bolt can be made from either a

[0023] Solid material “solid bolts” according to ZNG811008 as well as from a

[0024] Material pairing “hybrid bolt” according to ZNG811020 will be used.

[0025] A solid bolt according to ZNG811008 can be formed from a base material which can subsequently be coated with a wear-resistant layer. The following base materials can be used:

[0026] Structural steel

[0027] stainless steel

[0028] - Wear-resistant steel 1.8714; 1.8722; 1.8734.

[0029] A bolt can be a hybrid bolt made up of several components. A hybrid bolt can comprise an outer and an inner core. The inner core can be inserted into a hole or passage in the outer core. The outer core can be made of a metal. The outer core can be made of a tough steel. A tough steel exhibits high resistance to fracture and deformation, especially under dynamic loads. Examples of tough steels are: S355J2 (structural steel according to EN 10025-2), 42CrMo4 (quenched and tempered steel according to EN 10083-3), 16MnCr5 (case-hardening steel according to EN 10084), 1.4301 (X5CrNi18-10, stainless steel V2A), AISI 4340 (high-strength alloy steel), AISI 4140 (comparable to 42CrMo4, chromium-molybdenum steel), Hadfield steel (X120Mn12, manganese steel).

[0030] The inner core can be made of a high-strength solid material with high wear resistance. The following base materials can be used for the inner core: aluminum oxide (Al₂O₃), zirconium oxide (ZrO₂), or tungsten carbide.

[0031] The inner core may be inserted into the outer core and bonded in place. A plate may be provided on one end face of the inner core, which may be made of steel, in particular a tough steel.

[0032] The hybrid bolt may have a coating as a protective layer.

[0033] To solve the problem, a mixer with a shaft and a mixing tool attached to the shaft can be provided. The mixing tool can be as described previously. During mixing, the body can be in contact with a drum wall of the mixer. There are then no other parts between the drum wall and the body. The body is then located in an area that is particularly susceptible to wear.

[0034] The mixer can be a vertical mixer. In this case, the shaft runs vertically inside the mixer. The mixer can also be a horizontal mixer. In this case, the shaft runs horizontally.

[0035] To repair a mixer tool damaged by wear, a worn body can be replaced with a new one without also replacing the tool arm. Several worn bodies can be replaced together with their screws, or just one or more worn bodies can be replaced. Alternatively or additionally, in one embodiment, the mounting bracket is replaced.

[0036] In one aspect, a mixing tool for an industrial mixer is provided. The mixing tool can include a holder. The mixing tool can include a body. The body can be held by the holder. The body can project from the holder for mixing. The body can be a bolt or a plate. The mixing tool can include a protective layer. The protective layer can be arranged on the body. The protective layer can be designed as a slip-on body with a blind hole. The protective layer can be designed as a slip-on sleeve. One end of the sleeve may be closed. Thus, a body with a blind hole can be a sleeve with a closed end.

[0037] The attached sleeve allows for easy replacement of the protective layer.

[0038] The sleeve with the closed end may have been manufactured in one piece. This means that several parts were not produced separately and then assembled to form the sleeve with a closed end.

[0039] The body can be the main element of the mixing tool. Examples of bodies include bolts, plates, pins, and paddles.

[0040] In addition to the attached sleeve, other methods are available for applying a protective layer to the bolt.

[0041] One alternative method is laser cladding with tungsten carbide. In this process, tungsten carbide is applied to the surface of the bolt using a laser beam. The laser beam melts the tungsten carbide material and metallurgically bonds it to the bolt's base material. Laser cladding allows for precise control of the layer thickness and geometry. The protective layer applied by laser cladding exhibits high adhesion to the bolt.

[0042] A second alternative method is the brazing of carbide plates. In this process, prefabricated carbide plates are brazed onto the surface of the bolt. The brazing alloy forms a metallurgical bond between the carbide plates and the base material of the bolt. The carbide plates are made of a wear-resistant material and protect the bolt from abrasion during the mixing process.

[0043] In another embodiment, the body is made entirely of tungsten carbide. In this variant, the entire bolt consists of tungsten carbide. There is no separate core made of another material. The bolt made entirely of tungsten carbide provides wear protection across its entire volume. This embodiment is suitable for applications with high wear requirements. One method for manufacturing a mixing tool involves placing a sleeve onto a body to provide a protective layer. The sleeve is placed onto a lower portion of the body. This lower portion of the body is intended for contact with the mixture during operation.

[0044] The sleeve is preferably made of tungsten carbide. Tungsten carbide exhibits high wear resistance and protects the body during the mixing process.

[0045] In an alternative embodiment, the protective layer is applied by laser cladding with tungsten carbide. In laser cladding, tungsten carbide is applied to the surface of the body using a laser beam. The laser cladding creates a metallurgical bond between the protective layer and the body.

[0046] In another alternative embodiment, the protective layer is applied by soldering on carbide plates. The carbide plates are soldered onto the surface of the body. The soldering creates a strong bond between the carbide plates and the body.

[0047] The body can be a bolt. In an alternative embodiment, the body is a plate.

[0048] The procedure may involve creating a blind hole in the body. This blind hole serves to hold the body in a fixture. The blind hole is created in an upper region of the body.

[0049] In one embodiment, the body is made of tungsten carbide. A body made of tungsten carbide exhibits high wear resistance throughout its entire structure.

[0050] A protective layer or the entire body can be made of a tungsten carbide material. Examples of tungsten carbide materials include sintered tungsten carbide, tungsten carbide-cobalt compounds, tungsten carbide-nickel compounds, and nanocrystalline tungsten carbide. A tungsten carbide material can offer a high level of wear resistance.

[0051] A protective layer can consist of alternative materials. Examples of alternative materials include titanium carbide, chromium carbide, boron carbide, and silicon carbide. Other alternatives include ceramic materials, hard metal alloys, and wear-resistant steel alloys. The choice of material may depend on the specific requirements of the mixing process.

[0052] They show

[0053] Figure 1: Mixing tool;

[0054] Figure 2: Sectional view of a mixing tool;

[0055] Figure 3: Mixing tool;

[0056] Figure 4: Bolt;

[0057] Figure 5: Mixer;

[0058] Figure 6: Bolt;

[0059] Figure 7: Bolt.

[0060] Figure 1 shows a mixing tool 1 for an industrial mixer. The mixing tool 1 can include a holder 2. The holder 2 can hold at least one body. The body can be a bolt 3. The holder 2 can hold a plurality of bodies, for example, bolts 3. The bodies or bolts 3 can project beyond the holder 2. The bodies or bolts 3 can form a first end face of the mixing tool 1 as shown in Figure 1.

[0061] The mixing tool 1 can include an arm 4. One end of the arm can form a second end face of the mixing tool 1, as can be seen in Figure 1. The holder 2 can be attached to the arm 4.

[0062] Bracket 2 can extend laterally from arm 4. Bracket 2 can extend laterally from arm 4 on both sides. Arm 4 can terminate at one end at the center of bracket 2, so that arm 4 and bracket 2 resemble the letter T. One section 5 of arm 4 can be angled relative to the other section 6 of arm 2 to facilitate mixing. This ensures that bolts 3 and section 6 of arm 4 do not lie in the same plane.

[0063] Section 6 of arm 4 can be straight. The cross-section of section 6 of arm 4 can be at least predominantly constant and / or rectangular. The width and thickness of section 6 do not change if the cross-section is constant. The cross-section of section 5 of arm 4 can widen towards the support to provide stability to the support 2. The cross-section of section 5 of arm 4 can be at least predominantly rectangular. A rectangular cross-section of section 6 of arm 4 can be rotated relative to a rectangular cross-section of section 5. The support 2 can then be rotated relative to section 6 in the same way to achieve good mixing results. For example, it can be achieved in this way that the support 2, with the bodies attached to it, is tilted and rotated relative to a shaft in the mixing direction to achieve good mixing results.The aim is to convey the mixture towards the shaft and to enhance the mixing effect. This objective, whereby the support 2 with the attached bodies are tilted and rotated relative to a shaft when viewed in the mixing direction, can also be achieved through other geometries of the arm 4 and / or the support 2.

[0064] The arm 4 can be connected to the bracket 2 by means of one or more screws. The one or more screws may be located behind a cover 7. The cover 7 may be attached to the arm 4 by a weld.

[0065] The bracket 2 can have a receptacle for a body. The bracket 2 can have multiple receptacles for multiple bodies. A receptacle can extend through the bracket. A body can then be inserted into a receptacle from one side. From the other side, the body can be secured, for example, with a screw. There can be a stop inside the receptacle for a body. A body can then be inserted into the receptacle until it reaches this stop. The body is then partially inside the bracket 2 and partially outside of it. A screw can be driven into the body from the other side to secure it to the bracket 2. The stop inside the bracket can also act as a stop for the screw head, allowing for a countersunk screw.

[0066] The one or more receptacles can be one or more holes 8 that pass through the holder 2. Within each hole 8, there can be at least one constriction that can form a stop for a body such as a bolt 3. A body may taper, for example, by means of a step. The tapered end can then only be inserted a limited way into a correspondingly dimensioned receptacle. A stop within the receptacle can then be omitted. It can also be achieved that a body can only be partially inserted into the receptacle. The body can then, for example, be a plate with a bolt protruding from it. The bolt can then be inserted into the receptacle, but not the plate.

[0067] Figure 2 shows a section of a mixing tool 1 in a sectional view. Figure 2 illustrates that the section 5 of the arm 4 can be connected to the bracket 2 by means of a screw 11. A countersink 9 for the screw may be provided. The countersink 9 can be protected from external contamination by the cover 7. The cover 7 and the adjacent surface 10 of the arm 4 can be made of metal so that the cover 7 can be attached to the metallic surface by welding. The weld can be designed so that the cover 7 can be removed if necessary without causing significant damage to the arm 4. A bracket 2 can therefore be replaced with minimal effort if required. Since the adjacent surface 10 is metallic, a new cover 7 can easily be attached after a replacement.The screw 11 can be screwed into an internal thread of the bracket 2.

[0068] Exposed surfaces of the mixing tool 1 can be formed by a protective layer 12. The fact that there may be a metallic and therefore relatively unprotected surface 10 is unproblematic, since, as intended, rotation in the case of Figure 2 is to be counterclockwise and the surface 10 is then practically unaffected by wear.

[0069] Mounting bracket 2 may be subject to greater wear and tear compared to arm 4. Therefore, it can be advantageous to be able to replace mounting bracket 2 occasionally. However, the frequency of such replacements will generally be low compared to the need to replace the body or bolt 3.

[0070] Figure 2 illustrates a possible angular position of bodies or bolts 3 relative to the main part of the arm 4 (section 6). Bolts 3 can form an angle of, for example, 65° with a horizontal line if the main part of the arm 4 forms an angle of 90° with the horizontal line. The metallic surface 10 can then also form an angle of 65° with the horizontal line. Other angles are also possible instead of 65°, which can be greater than 50° and / or less than 80°.

[0071] Figure 3 shows the mixing tool 1 in another view. The end region of the mixing tool 1, formed by the arm 4, can include one or more holes 13 for attaching the mixing tool 1 to a shaft using screws. Figure 3 also shows that more than one screw 11 can be present to connect the bracket 2 to the arm 4. It is clearly visible in Figure 3 that, viewed in the mixing direction, the bracket 2 can not only be tilted but also twisted relative to the main part of the arm 4 (i.e., the area above the arm section 5).

[0072] Figure 4 shows a view of a bolt 3. The bolt 3 can comprise a metallic core 15, which may be made of steel, for example. A protective layer 14, which may be made of tungsten carbide, for example, can be applied to the steel. The protective layer 14 is only partially shown to allow a view of the metallic core 15. The protective layer 14 does not need to completely cover the metallic core 15. Thus, the area that is located in the mounting bracket 2 when assembled can have a metallic surface without a protective layer 14. It may be sufficient to protect only one end 17 from wear by a protective layer 14 that is more wear-resistant than the core 15.

[0073] The end of the bolt 3, which can be inserted into a holder 2, can have a blind hole 16 with an internal thread to allow the bolt 3 to be fastened with a screw. The opposite end 17 can taper, which can be advantageous for mixing. The taper can be conical. The angle of the cone's surface can be between 10° and 15°. Figure 4 shows an example of an angle of 15°.

[0074] Figure 5 shows a cross-sectional sketch of a mixer 18. The mixer 18 can include a shaft 19. The shaft 19 can, for example, extend horizontally into the drum 20 of the mixer 18. The drum 20 can be cylindrical. The shaft 19 can pass through an end wall of the drum 20. The shaft 19 can have two shaft mountings 21 inside the drum. A mixing tool 1 can be attached to a shaft mounting 21, for example, by screws. Another bolt 2 with possible dimensions is shown in Figure 6. The dimensions are given only as examples. Other possible dimensions may deviate, for example, by up to 20% from the dimensions shown in Figure 6.

[0075] The core of the bolt 2 can be made of various materials. The core of the bolt can consist of an inner core 23 and an outer core 24. The outer core 24 can be made of a metal, such as steel. The outer core 24 can have a passage into which the inner core 23 is inserted, for example, up to an optionally provided stop. The passage adjacent to the inner core 23 can be closed by, for example, a plate-shaped part 22. The remaining accessible part of the passage can form a blind hole 16 with an internal thread. A protective layer 14 can be applied to at least one half of the bolt 2. The load-bearing capacity of the bolt 2 can be improved by providing the inner core 23.

[0076] The inner core 23 can be made of a ceramic. The inner core 23 can be made of an oxide such as aluminum oxide, zirconium oxide, or a carbide such as tungsten carbide.

[0077] FIG. 7 shows a sectional view of a bolt 3 for a mixing tool 1. The bolt 3 forms an interchangeable body of the mixing tool 1.

[0078] The bolt 3 has a core 24. The core 24 forms the main body of the bolt 3. The core 24 extends almost the entire length of the bolt 3.

[0079] The bolt 3 has a blind hole 16. The blind hole 16 is located at the upper end of the bolt 3. The blind hole 16 extends from the upper end face of the bolt 3 downwards into the core 24. The blind hole 16 is designed to be received in a holder 2 of the mixing tool 1. The blind hole 16 may have a V-shaped geometry at its base.

[0080] The bolt 3 has a protective layer 14. The protective layer 14 can be designed as a slip-on sleeve. One end face of the slip-on sleeve can be closed. The sleeve can be made of tungsten carbide. The protective layer 14 consists of tungsten carbide. The protective layer 14 can surround a lower region of the outer core 24. The protective layer 14 can extend over a substantial part of the length of the bolt 3. The protective layer 14 provides protection against wear during the mixing process. The upper region of the bolt 3 with the blind hole 16 is designed for insertion into the holder 2. The lower region of the bolt 3 with the protective layer 14 is designed for contact with the mixture.

[0081] The bolt 3 and the attached protective layer 14 can be shaped such that the protective layer 14 does not protrude beyond an adjacent surface of the bolt 3 after being attached. Alternatively, the bolt 3 and the attached protective layer 14 can be shaped such that the protective layer 14 does not recede beyond an adjacent surface of the bolt 3 after being attached.

[0082] In an alternative embodiment, the body is a plate instead of the bolt 3.

[0083] Reference symbol list:

[0084] 1 - Mixing tool

[0085] 2 - Bracket

[0086] 3 bolts

[0087] 4-arm

[0088] 5 - Section of the arm

[0089] 6 - Other section of the arm

[0090] 7 - Cover

[0091] 8-hole

[0092] 9 - Sinking

[0093] 10 - Metallic surface of the arm

[0094] 11 - screw

[0095] 12 - Protective layer

[0096] 13 - Hole in the end area of ​​the arm for fastening

[0097] 14 - Protective layer of the bolt

[0098] 15 - Metallic core of the bolt

[0099] 16 - Blind hole with internal thread in the bolt

[0100] 17 - Tapered end of the bolt

[0101] 18 - Mixer

[0102] 19 - Mixer wave

[0103] 20 - Mixer drum

[0104] 21 - Shaft fastening

[0105] 22 - plate-shaped part

[0106] 23 - inner core

[0107] 24 - (outer) core

Claims

1. Gebrüder Lödige Maschinenbau GmbH G70710WO Claims 1. Mixing tool (1) for an industrial mixer (18) with a holder (2), with an interchangeable body which is held by the holder (2) and which projects opposite the holder (2) for mixing.

2. Mixing tool (1) according to the preceding claim, characterized in that the body is a bolt (3) or a plate.

3. Mixing tool (1) according to one of the preceding claims, characterized in that the body forms an end of the mixing tool (1) and an arm (4) forms an opposite end of the mixing tool (1), wherein the holder (2) is attached to the arm (4).

4. Mixing tool (1) according to the preceding claim, characterized in that the holder (2) extends laterally from the arm (4) in the shape of a T.

5. Mixing tool (1) according to the preceding claim, characterized in that the holder (2) projects obliquely from the arm (4) or from a section (5, 6) of the arm (4).

6. Mixing tool (1) according to one of the four preceding claims, characterized in that the holder (2) is detachably connected to the arm (4).

7. Mixing tool (1) according to the preceding claim, characterized in that the holder (2) is connected to the arm (4) by at least one screw (8).

8. Mixing tool (1) according to one of the six preceding claims, characterized in that the arm (4) comprises a protective layer (12) on its surface.

9. Mixing tool (1) according to the preceding claim, characterized in that the protective layer (12) is at least 1 mm or at least 2 mm thick and / or that the protective layer (12) is not thicker than 5 mm or not thicker than 4 mm.

10. Mixing tool (1) according to one of the two preceding claims, characterized in that the arm (4) comprises a surface area (10) without a protective layer (12) on which a cover (7) for covering a screw is welded, wherein the surface area (10) is present at the end of the arm (4) to which the holder (2) is attached.

11. Mixing tool (1) according to one of the preceding claims, characterized in that the body is held by a screw (8).

12. Mixing tool (1) according to one of the preceding claims, characterized in that the holder (2) consists at least predominantly of metal such as steel.

13. Mixing tool (1) according to one of the preceding claims, characterized in that a surface of the body consists of tungsten carbide (15) and / or the body consists entirely of tungsten carbide (15).

14. Mixing tool (1) according to one of the preceding dependent claims, characterized in that a plurality of bolts (3) are provided as bodies which are arranged parallel to each other.

15. Mixing tool (1) according to the preceding claim, characterized in that a distance between two adjacent bolts (3) is greater than the diameter of each bolt (3).

16. Mixing tool (1) according to one of the two preceding claims, characterized in that the length of a bolt (3) projecting from the holder (2) is greater than its diameter.

17. Mixing tool (1) according to one of the preceding dependent claims, characterized in that the bolt (2) comprises a core (24) and a protective layer (14) designed as a sleeve on the core (24).

18. Mixing tool (1) according to one of the preceding dependent claims, characterized in that the bolt (2) comprises an outer metallic core (24), an inner core (23) formed of a ceramic inserted into the outer core and a protective layer (14) on the outer core (24).

19. Mixer (18) with a shaft (19) and a mixing tool (1) attached to the shaft (19) according to one of the preceding claims.

20. Method for repairing a mixing tool (1) damaged by wear with a mixer (18) according to the preceding claim, characterized in that a worn body is replaced with a non-worn body, but not an arm (4) of the mixing tool (1).

21. Method according to the preceding claim, characterized in that only one or more worn bodies together with screws (11) or only one or more worn bodies are replaced.

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