Crusher

Abstract

A crusher (1) comprising: a ball mill (2) having a steel drum (3) containing a plurality of steel balls (4) therein, configured to obtain powder having a particle size of 25 μm to 500 μm, preferably 200 μm to 300 μm, i.e., the main size of each powder particle being 25 μm to 500 μm, preferably 200 μm to 300 μm; and a refrigeration circuit (6) for refrigerating at least a portion of the steel drum (3), comprising a refrigeration unit (5) suitable for supplying a carrier fluid at a temperature of -150 degrees or less, a sleeve (7) for the inflow of the carrier fluid supplied by the refrigeration unit (5), and a discharge sleeve (9) for complete circulation in the refrigeration circuit (6) and discharge of the carrier fluid at the end of transport to the suction duct (10) of the refrigeration unit (5).

Description

Technical Field

[0001] The present invention particularly relates to a crusher suitable for reducing materials selected from fabrics, leathers, or the like (regardless of whether they are of natural origin or obtained by a synthetic process) into very small pieces.

Background Art

[0002] An increasingly important problem that has emerged as a result of the spread of the circular economy relates to the way materials are recycled.

[0003] In fact, while recycling is easy for some materials (e.g., metals and glass), there are others that are difficult to process (which are essentially of high economic value).

[0004] Among these, it is appropriate to mention all materials used in the production of fabrics, leathers, and generally clothing, and / or upholstery, and / or components of furniture and the like.

[0005] Recycling polymeric materials can produce fabrics or materials with similar properties (e.g., fibers for the production of new clothing that may be used to provide clothing products, may be supplied to the fiber industry for the production of new clothing, can obtain yarns, polyester or polyethylene waste), while providing a recycling that allows obtaining new raw materials for the same industrial sector starting from fiber or leather material waste has been impossible until now.

[0006] The applicant of the present application is the right holder of International Publication No. WO 2022 / 089782 regarding an apparatus and method for producing clothing products and the like from fiber waste, and / or leather material waste, and / or clothing industry material waste, and / or materials with similar properties.

[0007] The technical solutions described in International Publication No. 2022 / 089782 are deemed suitable for the full achievement of the set objectives.

[0008] As a result of research activities on the apparatus described in International Publication No. 2022 / 089782, it has been recognized that in order to obtain semi-finished products that can be processed more easily to obtain high-quality finished products, it is necessary to optimize the crushing of materials selected from waste fabrics, surplus products and / or residual inventory, waste clothing, waste leather, waste clothing accessories, and similar materials. [Overview of the project]

[0009] Currently, there are no known types of crushers at the industrial level that can effectively perform the operations envisioned by the invention (and thus guarantee productivity that would attract sufficient interest for industrial applications), making it impossible to implement the contents of International Publication 2022 / 089782, even for the production of high-quality garment products (or semi-finished products suitable for their production).

[0010] The object of the present invention is to solve the problems described above and to provide a crusher suitable for operating on a probabilistic mixture of materials selected from waste fabrics, excess products and / or residual inventory, clothing waste products, waste leather, waste clothing accessories, and similar items. Among these objects, an object of the present invention is to devise a crusher suitable for providing materials that are divided into very small, uniform particles.

[0011] Another object of the present invention is to devise a crusher suitable for providing materials that may be used to implement the contents of International Publication No. 2022 / 089782 for the production of garment products and / or upholstery and / or furniture products having high quality standards.

[0012] Another object of the present invention is to devise a crusher suitable for providing materials that may be used to implement the contents of International Publication 2022 / 089782 for the production of semi-finished products suitable for the production of garment products having high quality standards, and / or upholstery and / or furniture products.

[0013] A further objective of the present invention is to provide a crusher that is low-cost, relatively simple to provide in practice, and has guaranteed applications.

[0014] These objectives and their respective goals, as well as other objectives that become clearer below, A ball mill comprising a steel drum containing multiple steel balls, configured to obtain powder having a particle size of 50 μm to 400 μm, preferably 200 μm to 300 μm, i.e., a dominant size of each powder particle of 50 μm to 400 μm, preferably 200 μm to 300 μm, and at least 60% of its mass, A refrigeration unit suitable for supplying carrier fluid at temperatures below -150 degrees Celsius, This is achieved by a crusher comprising a refrigeration circuit for refrigerating at least a portion of the steel drum, the refrigeration circuit comprising a sleeve for the inflow of the carrier fluid supplied by the refrigeration unit, and a discharge sleeve for complete circulation in the circuit and discharge of the carrier fluid at the end of transport to the suction duct of the refrigeration unit. [Brief explanation of the drawing]

[0015] Further properties and advantages of the present invention will become more apparent from the description of preferred but non-exclusive embodiments illustrated by the non-limiting examples of the accompanying drawings. [Figure 1] A schematic diagram of a possible embodiment of the crusher according to the present invention. [Figure 2] A schematic cross-sectional view of the drum of the crusher according to the present invention, obtained along the transverse plane. [Figure 3] A schematic side view of the crusher according to the present invention. [Modes for carrying out the invention]

[0016] Referring particularly to the figure, the crusher according to the present invention is generally designated by reference numeral 1.

[0017] The crusher 1 includes a ball mill 2, which is equipped with a steel drum 3 containing multiple steel balls 4.

[0018] The crusher 1 is configured to obtain powder having particle sizes from 25 μm to 500 μm, that is, it must be capable of providing powder in which the main size of each particle is from 25 μm to 500 μm.

[0019] With particular reference to a preferred embodiment, at least 60% of the mass of powder discharged from the crusher 1 shall preferably be powder with a particle size of 200 μm to 300 μm (an embodiment may specify that a value of 250 μm is considered ideal), i.e., the dominant size of each particle shall be 200 μm to 300 μm (an embodiment may specify that a value of 250 μm is considered ideal).

[0020] With regard to the utilization of the powder discharged from the crusher 1, it is identified that better results can be achieved if at least 70% of the powder has a particle size of preferably 200 μm to 300 μm (an embodiment is identified in which a value of 250 μm is considered ideal), i.e., if the dominant size of each particle is 200 μm to 300 μm (an embodiment is identified in which a value of 250 μm is considered ideal).

[0021] Generally, the higher the mass percentage of powder particles with a particle size below a predefined threshold, the better the results of the processing performed by the crusher 1.

[0022] Furthermore, the crusher is equipped with a refrigeration unit 5 suitable for supplying carrier fluid at temperatures below -150 degrees Celsius.

[0023] The crusher 1 further comprises a circuit 6 for refrigerating at least a part of the steel drum 3, which includes a sleeve 7 for the inflow of the carrier fluid supplied by the refrigeration unit 5 and a discharge sleeve 9 for the discharge of the carrier fluid at the end of the complete circulation in the circuit 6 and the transport to the suction duct 10 of the refrigeration unit 5. The discharge sleeve 9 is thus for discharge and constitutes the end of the outflow of the used carrier fluid.

[0024] In the attached drawings, for heat removal by conduction, the refrigeration circuit 6 is shown as piping (substantially a coil) arranged along the outer surface of the drum 3.

[0025] In this case, a rotary (annular) distribution unit may be appropriately interposed between the inflow sleeve 7 and the first duct 8, allowing the circuit 6 incorporating the drum 3 rotating via the refrigeration unit 5 to be supplied. The unit 5 is fixed but allows the free rotation of the drum 3. Similarly, the rotary (annular) distribution unit is also interposed between the discharge sleeve 9 of the circuit 6 and the suction duct 10 of the refrigeration unit 5 to allow the free rotation of the drum 3 (and the circuit 6 and its associated ports 7, 9) with respect to the fixed unit 5 (as the ducts 8, 10 are fixed).

[0026] Of course, this illustration is provided only by way of a non-limiting example regarding one of many possible embodiments: the introduction of a completely different refrigeration circuit 6 for lowering the temperature of the drum 3 (especially its contents) is not excluded.

[0027] The direct supply of a carrier fluid (such as liquid or gaseous nitrogen, or liquid or gaseous helium, or liquid or gaseous argon) to the surface or inside of the drum 3 is also not excluded.

[0028] It should be noted that the ball mill 2 may advantageously comprise at least one motor-driven element configured to drive the rotation of the drum 3 according to the rules of motion that may be set by the control and management unit.

[0029] This method makes it possible to apply rules of motion that allow for maximizing the effect of the ball on the material placed inside the drum 3. In addition to the controllable duration of the work cycle, the motor drive element of the drum 3 may be an electric motor driven via an inverter in order to control the direction and rotational speed of the drum 3.

[0030] More specifically, the crusher 1 according to the present invention, positioned in a selected component between the drum 3 and the refrigeration circuit 6, should be specified to include at least one sensor of a type selected from: a temperature sensor (which can, for example, monitor the temperature inside the drum 3 or the temperature of the carrier fluid circulating in the circuit 6); a carrier fluid flow rate sensor (to set the flow rate of the carrier fluid flow in the circuit 6 so as to ensure that the contents of the drum 3 are properly maintained at a predetermined temperature); and a visual sensor for confirming the size of individual particles to be crushed.

[0031] The visual sensor sequentially identifies the particle size of the powder particles, and accordingly controls the operation of the drum 3 to achieve predetermined values ​​for the above parameters in the shortest possible time.

[0032] The refrigeration unit 5 may preferably be a cryocooler: this definition means a device capable of bringing the carrier fluid to a temperature of 93K (-179.85°C) or lower.

[0033] The ability to allow the carrier fluid to reach very low temperatures is a significant advantage, as this effect embrittles the raw materials processed within drum 3.

[0034] In particular, the crusher 1 according to the present invention is suitable for crushing materials selected from waste fabrics, overproduction and / or residual inventory, waste clothing, waste leather, waste clothing accessories, and similar materials, the fibers of which are typically flexible and elastic (at ambient temperature), particularly prone to energy dissipation and highly deformable. Naturally, the properties of such materials make them completely unsuitable for effective crushing inside the ball mill 2; if the materials are instead maintained at cryogenic temperatures, they undergo changes that make them harder and more brittle, and thus may be crushed by collision with the balls 4 inside the drum 3. The lower the temperature (and closer to the vitrification temperature of the materials listed above), the more efficient and adaptable the resulting crushing will be. Naturally, different operating temperatures of the carrier fluid should be adopted depending on the different types of raw materials introduced (natural fibers, synthetic fibers, leather, etc.).

[0035] The raw materials supplied into the drum 3 are already coarsely ground so that each piece may react best with the heat and mechanical stress inside the crusher 1 according to the present invention.

[0036] The refrigeration unit 5 may preferably be selected from dilution type cryocoolers (which may be allowed to reach temperatures close to 0K, corresponding to so-called absolute zero, with a value of -273.15 degrees Celsius), cryocoolers based on the Gifford-McMahon refrigeration principle (equipped with a pneumatically driven refrigeration cycle), cryocoolers with cascade compressors, cryocoolers based on the evaporation of liquid nitrogen, cryocoolers based on the evaporation of liquid helium, cryocoolers based on the evaporation of liquid argon, and analogues thereof.

[0037] The choice of making the drum 3 and ball 4 from steel (preferably stainless steel) for the ball mill 2 stems from the need to use materials that do not impair mechanical properties when operating at cryogenic temperatures.

[0038] In the type of crusher 1 currently described, using a typical ball mill 2 results in frequent breakage and interruptions. For example, the balls (especially those made of ceramic or flint) become brittle and are damaged during the operation of the mill; similar problems may occur in mills equipped with drums made of materials other than steel (preferably stainless steel).

[0039] With particular reference to embodiments of undoubted interest in application and practice, it is identified that drum 3 may be advantageously configured for instantaneous containment of a given batch of material to be crushed, as a result of defining the internal dimensions of the chamber. In fact, the design of the ball mill 2 (particularly drum 3) is dependent on the capacity of individual batches, during which the mill 2 must be operable.

[0040] The productivity of crusher 1 is a parameter that guides its design.

[0041] For example, a productivity level considered effective for a prototype with guaranteed practical value is identified as 50 kg of shredded fiber waste per hour (assuming the material fed into the drum consists of fragments no larger than 6 mm in size).

[0042] Drum 3 must have at least one opening for feeding in the material to be crushed and for removing the resulting powder.

[0043] Preferably, there are two such openings: a first intake opening for feeding in the material to be crushed, and a second discharge opening for removing the resulting powder. The operations for feeding in the raw materials and removing the powder may be manual (performed directly by an operator), semi-automatic (for example, the operator is provided with the raw materials, but the removal is performed automatically to prevent the operator from coming into contact with the powder, which is close to cryogenic temperature), or automatic (both feeding in the raw materials and removing the powder are performed by an automated device).

[0044] In particular, the crusher 1 according to the present invention preferably comprises at least one conveying line configured for operations selected from: conveying the raw material to be crushed (e.g., fiber waste fragments) to a drum 3 and conveying the powder obtained at the end of the work cycle of the ball mill 2 to the next work station.

[0045] Naturally, the crusher 1 according to the present invention comprises two different operating methods.

[0046] The first method of operation provides batch grinding, in which the materials listed above are loaded into drum 3 while crusher 1 is stopped, then drum 3 is closed and the grinding cycle begins. When grinding is complete, crusher 1 is stopped and the resulting powder is collected.

[0047] A second method of operation provides continuous grinding: in this case, the loading of the materials listed above occurs continuously during the operation of the crusher 1, and similarly, the recovery of the produced powder occurs continuously when it reaches a desired (set) particle size, estimated using, for example, a classifier introduced into the recirculation system.

[0048] The scope of protection of the present invention also preferably extends to any apparatus for producing semi-finished products constituting raw materials for additive manufacturing, comprising at least one shredder (with a maximum size of less than 15 mm and preferably capable of providing fragments of about 5 to 7 mm) selected from blade crushers, impact mills, mills and similars. The apparatus downstream of the shredder preferably comprises at least one crusher 1 of the types described above.

[0049] Furthermore, the apparatus preferably includes at least one mixer for mixing the powder output from the crusher 1, which has at least one other substance selected from polyethylene glycol, polyether, and an organic binder as a solvent, thereby obtaining a mixture that constitutes a semi-finished product (to which the production of the apparatus is relevant).

[0050] The term "mixture" means any mixture, blend, or heterogeneous mixture that is solid, viscous, powdery, or liquid (but not exclusively, preferably thermoplastic granules, pellets, or blocks).

[0051] Furthermore, the apparatus may efficiently include at least one extruder for a mixture constituting a semi-finished product, which is located in an operating unit having at least two shafts.

[0052] In one possible embodiment, the mixer may be incorporated into an extruder that mixes the material at the suction before discharge.

[0053] The extruder may be suitable for additive molding, injection molding, and any method of delivering the finished product, which generally involves softening the material to form a new shape of a desired form.

[0054] In this embodiment, the mobile extruder is capable of depositing a layer of mixture onto a predetermined surface, thereby providing at least a portion of products selected from garment products, upholstery elements, furniture products, fashion accessories, gadgets, packaging components, and similar items. The deposition performed by the mobile extruder constitutes an implementation of a technique known as additive manufacturing, but the use of the extruder for injection molding and / or any other type of molding is not excluded.

[0055] Since it is possible to provide crushing of target materials (e.g., fibers, leather, and similar materials) with respect to target dimensional parameters (e.g., powder particle size of about 250 μm) through experimental laboratory processes, the crusher 1 according to the present invention is therefore recognized as an entirely new type of apparatus compared to the background art.

[0056] The crusher 1 according to the present invention is actually composed of a ball mill 2 equipped with a cryogenic crushing chamber (i.e., a chamber inside the drum 3): as shown, the crusher 1 is suitable for automatic or partially automatic operation.

[0057] By combining the increased embrittlement of the raw materials obtained through operation in a cryogenic environment with the effect of ball 4 (which can impart the desired kinetic energy to ensure the maximum crushing effect of the raw material fragments present in drum 3), the process can be operated using either a heterogeneous input matrix with the stochastic randomness of various components or a homogeneous matrix, and in either case, the desired degree of crushing can be obtained.

[0058] When installed in the apparatus according to the present invention, the crusher 1 must be equipped with upstream and downstream conveyors for connection to other operating processes present. To ensure proper control of the crusher 1 by other processes of the apparatus, the introduction of buffer stations interposed between the crusher 1 and the subsequent processes is provided.

[0059] Preferably, the crusher 1 cooperates with other processes of the apparatus according to the present invention using monitoring and data acquisition control in accordance with the logic standards of Industry 4.0.

[0060] Preferably, the present invention solves the problems described above and provides a shredder 1 suitable for operating on materials selected from waste fabrics, surplus products and / or residual inventory, clothing waste products, waste leather, waste clothing accessories, and similar items.

[0061] Preferably, the crusher 1 according to the present invention is adapted to supply material to be broken down into very small, uniform particles (as specified, the current preferred target is to obtain powder having a particle size of about 250 μm, but in the future, it is not ruled out to adopt different particle size values ​​within the previously specified range).

[0062] Preferably, the crusher 1 according to the present invention is suitable for providing materials that may be used to implement the contents of International Publication No. 2022 / 089782 for the production of garment products and / or upholstery and / or furniture products having high quality standards.

[0063] Preferably, the crusher 1 according to the present invention is adapted to provide materials that may be used to implement the contents of International Publication No. 2022 / 089782 for the production of semi-finished products suitable for subsequent production of garment products and / or upholstery and / or furniture products having high quality standards.

[0064] Effectively, the crusher 1 according to the present invention is relatively simple to provide and low-cost: these properties make the crusher 1 and the apparatus equipped therewith a practically guaranteed innovation.

[0065] The present invention as thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims, and all of the details may be further replaced by other technically equivalent elements.

[0066] In the embodiments shown, the specific properties shown with respect to a particular example may actually be interchangeable with other different properties present in other embodiments.

[0067] In fact, the materials used, as well as the dimensions, may be any materials that meet the requirements and are in line with the latest technology.

[0068] The disclosures of European Patent Application Publication No. 23158831.0 asserted in this application are incorporated herein by reference.

[0069] Where any technical feature referred to in any claim corresponds to a reference numeral, such reference numeral is included solely for the purpose of enhancing the understanding of the claim, and therefore does not have any limiting effect on the interpretation of each element exemplified by such reference numeral.

Claims

1. A ball mill (2) comprises a steel drum (3) containing a plurality of steel balls (4), and is configured to obtain powder in which at least 60% of the mass has a particle size of 25 μm to 500 μm, preferably 200 μm to 300 μm, i.e., the main size of each powder particle is 25 μm to 500 μm, preferably 200 μm to 300 μm. A refrigeration unit (5) suitable for supplying carrier fluid at a temperature of -150 degrees or lower, A crusher comprising: a refrigeration circuit (6) for refrigerating at least a portion of the steel drum (3), the refrigeration circuit (6) having a sleeve (7) for the inflow of the carrier fluid supplied by the refrigeration unit (5), and a discharge sleeve (9) for complete circulation in the refrigeration circuit (6) and discharge of the carrier fluid at the end of transport to the suction duct (10) of the refrigeration unit (5).

2. The crusher according to claim 1, wherein the ball mill (2) comprises at least one motor drive element configured to drive the rotation of the drum (3) according to rules of motion which may be set by the control unit and the management unit.

3. A crusher according to one or more of the preceding claims, characterized in that it comprises at least one sensor of a type selected from a temperature sensor, a carrier fluid flow sensor, and a visual sensor for checking the size of individual particles to be crushed, which is arranged on a component selected from the drum (3) and the refrigeration unit (6).

4. The crusher according to one or more of the preceding claims, characterized in that the refrigeration unit (5) is a type of cryogenic cryocooler selected from a dilution type cryocooler, a cryocooler based on the Gifford-McMahon refrigeration principle, a cryocooler having a cascade compressor, a cryocooler based on the evaporation of liquid nitrogen, a cryocooler based on the evaporation of liquid helium, a cryocooler based on the evaporation of liquid argon, and analogues thereof.

5. The crusher according to one or more of the preceding claims, wherein the drum (3) is configured for instantaneous containment of a predetermined batch of material to be crushed, thereby defining the dimensions inside the chamber.

6. The crusher according to one or more of the preceding claims, wherein the drum (3) is provided with at least one opening for feeding in the material to be crushed and for removing the resulting powder.

7. The crusher according to claim 6, characterized in that the opening has two openings: a first suction opening for feeding the material to be crushed in a manner selected from manual, semi-automatic, or automatic; and a second discharge opening for removing the resulting powder in a manner selected from manual, semi-automatic, or automatic.

8. A crusher according to one or more of the preceding claims, comprising at least one conveying line configured for operations selected from: conveying the raw material to be crushed to the drum (3); and conveying the resulting powder to the next work station.

9. Preferably, at least one shredder selected from blade shredders, impact mills, mills and similar devices, A crusher (1) as described in one or more of the preceding claims, At least one mixer for mixing the powder output from a crusher (1), having at least one other substance selected from polyethylene glycol, polyether, and an organic binder as a solvent, to obtain a mixture constituting the semi-finished product as a result, An apparatus for producing semi-finished products that constitute raw materials for additive manufacturing, characterized by comprising the above.

10. The apparatus according to claim 9, comprising at least one extruder for the mixture constituting the semi-finished product, arranged in an operating unit having at least two shafts, for a deposit layer of the mixture on a predetermined surface, and as a result comprising at least a portion of products selected from garments, upholstery elements, furniture products, fashion accessories, gadgets, packaging components, and the like, relating to a type of technology known as additive manufacturing.

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