Method for producing classifier wheels, rotors and stators, and machine and bearing housings, also with cooling or heating ducts for wind classifiers and comminution devices, in particular classifier mills and impact mills, for fractionating, micronizing, grinding and homogenizing different products, even clumpable and sticky products

Abstract

The invention relates to a novel method for producing classifier wheels, stators or rotors for comminution devices, in particular classifier or impact mills, for grinding and homogenizing different, even clumpable and sticky products, wherein once the properties of the pulverulent, granular or fibrous products or product mixtures to be comminuted or separated are determined, a production data set for the constructive design of the stator, classifier wheel or rotor is determined on the basis of the anticipated abrasion or material properties of the products or product mixtures. The material or a material mixture is then defined and a material data set processed. On the basis of the respective production and material data sets, an additive manufacturing device, in particular a 3D printer, is commissioned, and the particular classifier wheel, stator or rotor with its predetermined use-typical properties is additively manufactured, with longer lifetimes and uniform wear in the monolithic construction with different, additively combined materials being achieved.

Description

[0001] Process for the production of separator wheels, rotors and stators as well as machine and bearing housings, also with cooling or heating channels for air classifiers and comminution devices, in particular separator mills and impact mills, for fractionating, micronising, grinding and homogenising various, also sticky and sticky materials

[0002] Description

[0003] The invention relates to a method for producing classifier wheels, rotors and stators as well as machine and bearing housings, also with cooling or heating channels for air classifiers and comminution devices, in particular classifier mills and impact flow mills, for fractionating, micronising, grinding and homogenising different, also sticky and sticky materials, consisting of a cylindrical or conical or truncated cone-shaped base body with means for accommodating a drive and with conveyor blades and openings in classifiers or impact elements in mills, according to the preamble of claim 1.

[0004] Classifier wheels for devices for separating dusty, fibrous, or granular materials based on settling velocity under the influence of grain shape, size, and density are state-of-the-art. Such classifier wheels consist of a substantially cylindrical body with a concentric core or journal for accommodating a drive shaft, a plurality of flow openings distributed around the cylinder circumference, and a fines outlet.

[0005] Air separation is a process for separating dust-like materials. The separation is based on the settling velocity and is influenced by particle size, shape, and density. One quality criterion of an air separation system is its separation efficiency, whereby, if possible, all particles larger than the separation threshold are separated into the coarse material and smaller particles into the fine material.

[0006] Furthermore, rotors for impact mills are state-of-the-art. Such rotors are made of a metallic material and have a base body in a truncated cone shape, for example.

[0007] Impact elements for crushing the feed material are mounted on the outer circumference of the truncated cone.

[0008] In addition, it is known to design these impact elements to be replaceable so that in the event of wear, the entire base body of the rotor does not have to be replaced.

[0009] Further developments in the state of the art also show a screwless fastening of the striking elements, based on a tongue and groove construction.

[0010] Classifier wheels for countercurrent centrifugal air classifiers, for example, according to DD 290318 A7, have numerous holes on their outer surface that extend through to the interior of the classifier wheel. These holes are usually evenly distributed over the entire outer surface of the classifier wheel.

[0011] DE 41 40 656 CI discloses a classifying wheel for centrifugal wheel air classifiers with slot-shaped openings.

[0012] According to the teaching of DE 10 2004 053 530 B4, the task of specifying classifier wheels in an improved form was solved, whereby a longer service life with more uniform wear and a finer separation limit should be achieved.

[0013] In this regard, it is known to manufacture the base body of the separator wheel from a monolithic block, with the cylinder shell thickness being significantly greater than in the prior art. Between flow openings created, for example, by milling, webs remain in the cylinder shell, ensuring sufficient strength even in the event of wear.

[0014] The aforementioned cylindrical body is made of plastic, in particular a hard polymer, and is manufactured by casting and subsequent machining.

[0015] It is also possible to arrange a metal insert in the cylindrical body.

[0016] EP 3 568 520 B1 discloses a method for manufacturing a disc-type refiner segment for refining lignocellulosic material. Production data for the refiner segment are initially provided.

[0017] This data is then fed to a 3D printer, which then creates a pattern of a refiner segment.

[0018] This pattern then forms a mold for casting the actual disc-type segments.

[0019] WO 2019 / 141351 A1 relates to a 3D printing process for producing electromechanical components in which electrical conductors are embedded during the printing process.

[0020] From numerous investigations attributable to the applicant and its many years of experience, it has been shown that special classifying wheels or special rotors for impact mills must be developed for certain material components or material mixtures that are to be subjected to comminution treatment.

[0021] On the one hand, it is important to ensure that unavoidable abrasion of the comminution component is not, or only to a minimal extent, reflected in the fines, i.e., in the discharge device. On the other hand, a key task is to find an optimized geometry for the classifier wheels or for the impact elements of rotors, depending on the desired fineness down to the micrometer or nanometer range.

[0022] To manufacture such classifier wheels or rotors, it was previously necessary either to produce the final product from solid materials by machining or to resort to casting processes, which usually still require fine machining, in particular machining.

[0023] In particular, casting processes that require the prior production of a casting mold are only profitable if a larger number of corresponding crushing devices are to be produced.

[0024] The method described in the prior art of introducing a metal core into the interior of a classifier wheel is also technologically very complex, since a sufficiently strong connection between the metal core and the surrounding base body must be ensured.

[0025] From the above, it is therefore an object of the invention to provide a further developed method for the production of separator wheels or rotors for comminution devices, which makes it possible to react to different applications and separation tasks without resulting in a significant increase in costs in the production of the relevant components of the comminution device.

[0026] Furthermore, the new process to be developed should make it possible to provide different structures in the respective base body of the comminution device in a quasi-monolithic design, so that correspondingly less abrasive materials can be used only where there is a high mechanical load.

[0027] A partial object of the invention is to be able to design the method in such a way that the inertial mass of the comminution device rotating at high speed, in particular classifier wheels or rotors for impact mills, is reduced while maintaining at least the same strength. The object of the invention is achieved by the method according to claim 1, with the subclaims representing at least expedient embodiments and further developments.

[0028] The invention therefore relates to a process for the production of separator wheels, stators or rotors for comminution devices, in particular impact flow mills, for grinding and homogenising different materials, including those which are prone to build-up and sticky, whereby these assemblies basically consist of a cylindrical or conical or truncated cone-shaped base body with means for accommodating a drive as well as with conveyor blades and openings in the case of separators or impact elements in the case of mills.

[0029] According to the invention, the properties of the dust-like, granular or fibrous goods or corresponding mixtures of goods to be crushed or separated are first determined.

[0030] After these properties have been determined, particularly with regard to the expected abrasion of the comminution equipment, a production data set is developed for the structural design of the respective classifier wheel or rotor or stator on the basis of the expected abrasion and material properties of the goods or mixtures of goods.

[0031] Subsequently, the material or material mixture, or even a layered material construction, is determined for the respective separator wheel, rotor, or stator, with possible variation of the material or material mixture across the geometric dimensions of the base body and / or in relation to the impact elements, especially integrated ones. A material data set is then derived.

[0032] In the next step, the production and material data sets for the respective production are fed into an additive manufacturing facility, in particular a 3D printing facility.

[0033] This is then used for additive manufacturing of the respective classifier wheel, stator or rotor with its pre-determined or predetermined application-typical properties, whereby longer service life and even wear in the monolithic structure are achieved through and with different, additively combined materials, such as plastics, metals and / or composite materials.

[0034] In a further development of the invention, after producing a reference sample, this sample is used in a separating or comminuting device and operated at an n-fold higher load or capacity to simulate shortened continuous operation. This is followed by an analysis of the detected or detectable signs of wear and tear, along with an update of the production data set and / or the material data set.

[0035] With these updated data sets, appropriate series production or small series production can then be initiated.

[0036] Another development of the invention provides the possibility of determining incompatibilities between the constructive additive materials and the milled or feed material in advance to avoid possible contamination. Following this, the relevant materials are excluded or replaced for the additive manufacturing process. This prevents or reduces unwanted contamination of the fine material due to the unavoidable abrasion of the comminution device, which can lead to harmful contamination.

[0037] In addition, it is possible to add additives to the materials to be processed in order to, for example, detect wear at an early stage using optical means.

[0038] If this is implemented, for example, in the form of a layered structure, where the layers of a given thickness differ in their color from the outside to the inside, a color change or a color change can be used to conclude that wear is no longer acceptable and the corresponding rotor, stator or classifier wheel can be replaced.

[0039] An additive multi-layer or sandwich arrangement of different materials can be provided on structural parts or geometric sections of the classifier wheel or rotor that are subject to particularly high loads, for example in the area of ​​the fine material outlet or the impact elements.

[0040] Furthermore, it is possible to integrate monolithic components into the base body or to embed them in the base body during the additive manufacturing step.

[0041] These can in particular be components that increase stability.

[0042] Machine and bearing housings for comminution equipment can also be manufactured using the process described above. A particular advantage arises when integrated cavities or channels, especially heating or cooling channels, are created.

Claims

Claims 1. A process for the manufacture of separator wheels, rotors and stators as well as machine and bearing housings, also with cooling or heating channels for air separators and comminution devices, in particular separator mills and impact flow mills, for fractionating, micronising, grinding and homogenising different, also sticky and sticky materials, these consisting, among other things, of a cylindrical, conical or truncated cone-shaped base body with means for receiving a drive and with conveyor blades and openings in the case of separators or impact elements in the case of mills, characterised by the following steps: - Determining the properties of the dust-like, granular or fibrous materials or mixtures of materials to be crushed or separated; - Determination of a production data set for the structural design of the stator, separator wheel or rotor based on the expected abrasion and material properties of the goods or mixtures of goods; - Determination of the material or a material mixture for the respective separator wheel or the stator or rotor with possible variation of the material or the material mixture over the geometric extension of the base body and / or related to the impact elements and derivation of a material data set; - Feeding the production and material data set to an additive manufacturing facility, in particular a 3D printing facility; - additive manufacturing of the respective classifier wheel, stator or rotor with its predetermined application-specific properties, whereby longer service life and uniform wear are achieved in the monolithic structure with different, additively combined materials, such as plastics, metals and / or composite materials.

2. Method according to claim 1, characterized by Production of a reference sample of a stator, separator wheel or rotor and insertion of this into a separating or crushing device and operation of this with an n-fold higher load or capacity to simulate a shortened continuous operation, analysis of detected wear phenomena and updating of the production data set and / or the material data set.

3. Method according to claim 1 or 2, characterized by Determination of incompatibilities between the additive materials required for construction and the grinding or feed material in order to avoid possible contamination and exclusion or replacement of relevant materials for the additive manufacturing process.

4. Method according to one of the preceding claims, characterized in that additives are added to the materials to be additively processed in order to carry out early wear detection, in particular by optical means.

5. Method according to one of the preceding claims, characterized in that an additive multi-layer or sandwich arrangement of different materials is provided on particularly stressed structural parts or geometric sections of the classifier wheel, stator or rotor, for example at the fine material outlet or impact elements.

6. Method according to one of the preceding claims, characterized in that monolithic components are integrated or embedded during the additive manufacturing step.

7. Method according to claim 6, characterized in that stability-increasing or stiffening components are embedded.