Feed screw for feeding materials into the processing screw compressor.

Abstract

The present invention relates to a feed screw (3) for feeding into a processing screw (2), comprising a housing (43) and screw shafts (49, 50), the housing (43) having at least two housing holes (47, 48) formed therein, the screw shafts (49, 50) being rotatably arranged in the at least two housing holes (47, 48). The at least two housing holes (47, 48) and the at least two screw shafts (49, 50) define a free volume (V(x)) on their respective cross-sections (E(x)), the free volume (V(x)) decreasing monotonically in at least some regions to continuously compress the material in the conveying direction (46). In this way, the supply of materials with low bulk density can be improved.

Description

[0001] This patent application claims priority to European patent application EP 21 155 262.5, the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a feed screw for feeding materials into a processing screw mill. Furthermore, this invention relates to a processing apparatus and a method for operating such a processing apparatus having a feed screw. Background Technology

[0003] According to WO 2015 / 051859 A1 (corresponding to US2016 / 0346984A1), a side-feed screw extruder for feeding material into an extruder is known. To release the material from accompanying gaseous substances (such as air), the side-feed screw extruder includes a degassing casing arranged upstream in the conveying direction on the casing of the side-feed screw extruder. The side-feed screw extruder includes a screw conveyor with a large inclination and thrust edge profile in the material feed opening area. In the downstream conveying direction, the side-feed screw extruder has a screw conveyor with a reduced inclination and a normal sealing profile. This compacts the material and conveys it to the extruder under pressure. Summary of the Invention

[0004] The object of this invention is to manufacture a feed screw compressor that improves the feeding of materials with low bulk density into a processing screw compressor. Specifically, the bulk density of the material should be at most 600 g / dm³. 3 Especially up to 250g / dm 3 Especially up to 200g / dm 3 Especially up to 100g / dm 3 For example, the material should be recycled. The feed screw should especially allow for high material throughput so that the material can be processed in a simple and economical manner within the feed screw.

[0005] This objective is achieved by a feed screw mill having the features described in claim 1. Because the free volume V(x) decreases monotonically in the conveying direction, the material is continuously compressed in a simple and reliable manner, at least regionally. This compression can be adjusted as desired by reducing the free volume V(x). The processing screw mill is fed together with the compressed material, thereby achieving a high fill level for the processing screw mill. Due to the high fill level, the processing screw mill can be operated in a simple and economical manner.

[0006] The monotonically decreasing free volume V(x) over a region should be understood mathematically specifically as meaning that the free volume V(x) does not change abruptly, but the local derivative of the free volume V(x) in the conveying direction is continuous and negative at least regionally. The local derivative may also be zero in some regions. Preferably, the free volume V(x) decreases strictly monotonically at least in some regions, such that the local derivative of the free volume V(x) is completely negative in the conveying direction in some regions. Preferably, the free volume V(x) decreases monotonically, particularly strictly monotonically, at least in the region between the downstream end of the supply opening and the feed opening, and especially throughout the entire region between the downstream end of the supply opening and the feed opening.

[0007] The free volume V(x) is defined as the product of the free cross-sectional areas A(x) of at least two screw shafts in cross-section E(x) at the conveying point x and the pitch H(x). The free cross-sectional area A(x) is the area between the housing and at least two screw shafts in cross-section E(x). The pitch H(x) is defined as the height in the conveying direction when the screw shafts rotate once or once with the inclination S(x) of at least two screw shafts in cross-section E(x). The pitch H(x) is a nominal value related to the inclination S(x) in cross-section E(x) when the inclination S(x) varies in the conveying direction, particularly when the inclination S(x) decreases strictly monotonically. If the inclination S(x) decreases strictly monotonically in the conveying direction, then the pitch H(x) is greater than the actual pitch of at least two screw shafts.

[0008] The inclination S(x) in the cross section E(x) is defined at the screw's outer diameter Da(x), i.e., at the thread tooth tip. If the rotation axes of at least two screw shafts intersect the cross section E(x) perpendicularly, then all thread tooth tips of the at least two screw shafts have the same inclination S(x), making the calculation of the free volume V(x) independent of which thread tooth tip is considered. If, due to the conical arrangement of the at least two screw shafts, the rotation axes of the at least two screw shafts intersect the cross section E(x) at an angle not equal to 90°, then the inclinations at the thread tooth tips in the cross section E(x) may differ slightly from each other. In this case, the inclination S(x) should be the average of the inclinations of all thread tooth tips of the at least two screw shafts in the cross section E(x).

[0009] To reduce the free volume V(x), the free cross-sectional area A(x) and / or the pitch H(x) decrease monotonically, particularly strictly monotonically, in at least some regions along the conveying direction. Preferably, the free cross-sectional area A(x) and the pitch H(x) decrease monotonically, particularly strictly monotonically, in at least some regions along the conveying direction. During conveying, the material is thus transverse to and compressed along the conveying direction.

[0010] Preferably, the feed screw is designed as a side-feed screw. The side-feed screw can be laterally connected to the processing screw. At least two housing bores penetrate each other and, particularly, have a horizontal V-shaped cross-section. Preferably, the feed screw is designed with two shafts. Specifically, the feed screw has exactly two housing bores and exactly two associated screw shafts. Preferably, the feed opening has a horizontal V-shaped cross-section. The at least two screw shafts are specifically designed for rotational drive and / or close engagement in the same or opposite directions.

[0011] At least two screw shafts each include a shaft and at least one screw element. The at least one screw element forms one and / or two parts with the associated shaft. In the case of a two-piece design, at least one screw element is detachably connected to the shaft in a rotationally fixed manner. At least one screw element of each screw shaft has a thrust edge profile on the effective tooth face and / or the driven tooth face. The thrust edge profile on the effective tooth face and / or the driven tooth face may differ in the conveying direction. In particular, the tooth flank angle on the effective tooth face and / or the driven tooth face may increase in the conveying direction. For example, in the conveying direction, the tooth flank angle on the driven tooth face may be increased more than the tooth flank angle on the effective tooth face. This results in good air intake performance in the area of ​​the feed opening and sufficient rigidity in the areas of the feed opening and the compressed material. The at least two screw shafts have a plurality of threads N, where: 1 ≤ N ≤ 3, particularly 1 ≤ N ≤ 2, and particularly N = 2. Therefore, each screw shaft has N threaded edges with associated thread tooth tips.

[0012] Preferably, the feed screw compressor includes a feed hopper arranged on the housing and leading to a feed opening. Preferably, the free inlet cross-sectional area of ​​the feed hopper increases and / or decreases and / or remains constant within a certain range in the descending direction. Preferably, the feed hopper is configured in a segmented manner. In particular, the feed hopper is connected to a degassing device. The feed opening forms a feed chute in the housing. Preferably, the free inlet cross-sectional area of ​​the feed chute increases and / or decreases and / or remains constant within a certain range in the descending direction.

[0013] The feed screw compressor preferably includes at least one temperature control device. The at least one temperature control device can be operated by temperature control fluid and / or electrical means. The at least one temperature control device includes, for example, at least one fluid passage and / or at least one electric heating element. The at least one fluid passage is specifically integrated into the housing. The at least one electric heating element is integrated into the housing and / or arranged on the exterior of the housing.

[0014] The feed screw compressor according to claim 2 ensures better material feeding into the processing screw compressor. For example, the first feed point x1 is the beginning of the screw shaft of at least two screw shafts. For example, the second feed point x2 is the end of the housing arranged adjacent to the end of the screw shaft of at least two screw shafts. The ratio of the first free volume V(x1) to the second free volume V(x2) at the first feed point x1 defines compression. The larger the ratio V(x1) / V(x2), the greater the compression of the material as it is conveyed from the first feed point x1 to the second feed point x2. The following applies to the first free volume V(x1): V(x1) = A(x1)·H(x1). Correspondingly, the following applies to the second free volume V(x2) = A(x2)·H(x2).

[0015] For the ratio of the first free cross-sectional area A(x1) at the conveying point x1 in the first cross-section E(x1) to the second free cross-sectional area A(x2) at the conveying point x2 in the cross-section E(x2), the following applies in particular: 1 ≤ A(x1) / A(x2) ≤ 8, especially 1.5 ≤ A(x1) / A(x2) ≤ 7, especially 2 ≤ A(x1) / A(x2) ≤ 6.

[0016] For the ratio of the first pitch H(x1) in the first cross section E(x1) based on the first inclination S(x1) to the second pitch H(x2) in the cross section E(x2) based on the second inclination S(x2), the following applies in particular: 1 ≤ H(x1) / H(x2) ≤ 8, especially 1.1 ≤ H(x1) / H(x2) ≤ 5, and especially 1.2 ≤ H(x1) / H(x2) ≤ 3.

[0017] The feed screw compressor according to claim 3 ensures better material feeding into the processing screw compressor. Since the outer diameter of at least two screw shafts decreases monotonically, particularly strictly monotonically, in at least some regions along the conveying direction, the at least two screw shafts are conical. Preferably, the outer diameter of the at least two screw shafts decreases monotonically, particularly strictly monotonically, along the entire length of the at least two screw shafts along the conveying direction. The local derivative of the outer diameter in the conveying direction is preferably constant. The conical design of the at least two screw shafts ensures a large free cross-sectional area in the feed opening region and / or high material compression during conveying.

[0018] For a tapered design with at least two screw shafts, a tapering K is defined, where: in

[0019] D a (x1) describes the outer diameter of the screw at the delivery point x1 corresponding to the beginning of the screw shaft of the at least two screw shafts, and

[0020] Da (x3) describes the outer diameter of the screw at the delivery point x3 corresponding to the end of the at least two screw shafts, and

[0021] L describes the length of the at least two screw shafts.

[0022] For tapered K, the following applies in particular: 0.05 ≤ K ≤ 1, especially 0.05 ≤ K ≤ 1.

[0023] For the ratio D a (x1) / D a (x3), in particular: 1≤D a (x1) / D a (x3)≤4, especially 1.2≤D a (x1) / D a (x3)≤3, especially 1.3≤D a (x1) / D a (x3)≤2.5.

[0024] The screw inner diameter D of at least two screw shafts i (x) is constant or monotonically decreasing or strictly monotonically decreasing in the direction of transport, at least in some regions.

[0025] For at least two screw shafts at the delivery point x1, the screw inner diameter D i The ratio of (x1) to the screw inner diameter D1(x3) of at least two screw shafts at the delivery point x3, with particular application as follows: 1≤D i (x1) / D1(x3)≤5, especially 1.25≤D i (x1) / D1(x3)≤4, especially 1.5≤D i (x1) / D1(x3)≤3.

[0026] The feed screw compressor according to claim 4 ensures better material feeding into the processing screw compressor. The following applies particularly to the taper K: 0.1 ≤ K ≤ 0.9, especially 0.15 ≤ K ≤ 0.8, especially 0.2 ≤ K ≤ 0.7, especially 0.25 ≤ K ≤ 0.6, and especially 0.3 ≤ K ≤ 0.4.

[0027] For the ratio D a (x1) / D a (x3), in particular: 1≤D a (x1) / D a (x3)≤4, especially 1.2≤D a (x1) / D a (x3)≤3, especially 1.3≤D a (x1) / Da (x3)≤2.5.

[0028] The screw inner diameter D of at least two screw shafts i (x) is constant or monotonically decreasing or strictly monotonically decreasing in the direction of transport, at least in some regions.

[0029] For at least two screw shafts at the delivery point x1, the screw inner diameter D i The ratio of (x1) to the screw inner diameter D1(x3) of at least two screw shafts at the delivery point x3, with particular application as follows: 1≤D i (x1) / D1(x3)≤5, especially 1.25≤D i (x1) / D1(x3)≤4, especially 1.5≤D i (x1) / D1(x3)≤3.

[0030] The smaller the taper K, the larger the length L. If the length L is too large, a large leverage force acts on at least two screw shafts, which will put great stress on the bearings used to support at least two screw shafts on the housing or gearbox bearings. In addition, if the length L of at least two screw shafts is too large, the production of the feed screw mill is uneconomical.

[0031] A larger taper K corresponds to a smaller length L. If the length L is too small, the conveying efficiency of at least two screw shafts will be poor.

[0032] The length L is specifically the distance between conveying points x1 and x3. The following applies in particular to length L: 0.3m ≤ L ≤ 4m, especially 0.5m ≤ L ≤ 3.5m, especially 0.7m ≤ L ≤ 3m, especially 0.9m ≤ L ≤ 2.5m.

[0033] In the axial section, the envelope of each screw shaft forms an angle with the associated axis of rotation, particularly at least 2 degrees and at most 10 degrees, particularly at least 2.5 degrees and at most 8 degrees, particularly at least 3 degrees and at most 6 degrees. The envelope of each screw shaft is defined by the screw outer diameter at each delivery point.

[0034] The feed screw compressor according to claim 5 ensures better material feeding into the processing screw compressor. The housing aperture decreases monotonically in at least some areas along the conveying direction, particularly strictly monotonically. The following applies to the relative clearance between the housing and at least one screw shaft at the conveying point x: in

[0035] D G (x) describes the aperture of the housing at the delivery point x, and

[0036] D a(x) describes the outer diameter of the screws of at least two screw shafts at the delivery point x.

[0037] Preferably, the relative gap s(x) is constant in the conveying direction x and / or increases in the conveying direction.

[0038] For the shell length L G The screw outer diameter D of at least two screw shafts at the feed point x1 corresponding to the beginning of the screw shaft. a The ratio of (x1) is preferably applicable as follows: 2≤L G / D a (x1)≤15, especially 3≤L G / D a (x1)≤10, especially 4≤L G / D a (x1)≤6.

[0039] The feed screw compressor according to claim 6 ensures better material feeding into the processing screw compressor. Since the rotation axes form an angle α, they extend towards each other in the conveying direction. The tapered arrangement of at least two screw shafts ensures a large free cross-sectional area in the region of the feed opening and / or high compression during conveying. Large-volume materials with low bulk density can be fed through the feed opening in a simple manner.

[0040] At least two screw shafts are concentrically arranged with their respective axes of rotation in at least two housing bores. Preferably, the feed screw compressor includes at least one electric drive motor and / or at least one gear, particularly a branch gear. Preferably, the gear has at least two output shafts whose respective axes of rotation form an angle β, where β = α. Due to this tapered design of the gears, the screw shafts can be rotated in a simple manner.

[0041] Furthermore, the feed screw compressor may include at least two direct drives that directly drive the rotation of at least two screw shafts, i.e., without the insertion of gears. The feed screw compressor may include at least one angle compensation element, such as a universal joint and / or a drive belt and / or drive chain, which compensates for the angle between the respective rotational axis of the at least two screw shafts and the associated output shaft of the gear and / or the drive shaft of the driver.

[0042] To seal at least two screw shafts onto the housing, the feed screw compressor specifically features at least two packing glands. These at least two packing glands are specifically arranged on the outside of the housing, preferably in the area of ​​the gearbox lantern. This gearbox lantern mechanically connects the housing to the gears. The coupling of the at least two screw shafts to the corresponding output shafts of the gears occurs within the gearbox lantern.

[0043] The feed screw compressor according to claim 7 ensures better material feeding into the processing screw compressor. Ratio Da (x) / D i (x) is constant and / or decreases and / or increases in at least some regions along the conveying direction. This is achieved by means of the ratio D. a (x) / D i (x), adjusting the thread depth of at least two screw shafts in a desired manner. This thread depth affects the free volume V(x). For the ratio in

[0044] D a (x1) indicates the outer diameter of the screw at the delivery point x1 corresponding to the beginning of the screw shaft of the at least two screw shafts.

[0045] D i (x1) represents the inner diameter of the screw at the delivery point x1 of at least two screw shafts.

[0046] D a (x3) indicates the outer diameter of the screw at the delivery point x3 corresponding to the end of the screw shaft of the at least two screw shafts, and

[0047] D i (x3) represents the screw inner diameter at the delivery point x3 of at least two screw shafts.

[0048] For the ratio d, the following applies in particular: 0.62 ≤ d ≤ 1.22, especially 0.82 ≤ d ≤ 1. Preferably, the following applies: d = 1.

[0049] The feed screw compressor according to claim 8 ensures better material feeding into the processing screw compressor. Ratio H(x) / D a (x) is at least partially constant and / or decreasing in the conveying direction. Preferably, the following applies to the ratio. in

[0050] H(x1) indicates the pitch of at least two screw shafts based on the inclination S(x1) at the feed point x1 corresponding to the beginning of at least two screw shafts.

[0051] D a (x1) describes the outer diameter of the screw at least two screw shafts at the conveying point x1.

[0052] H(x3) represents the pitch of at least two screw shafts based on the inclination S(x3) at the feed point x3 corresponding to the screw ends of at least two screw shafts.

[0053] D a (x3) describes the outer diameter of the screws of at least two screw shafts at the conveying point x3.

[0054] For the ratio h, the following applies in particular: 0.5 ≤ h ≤ 1.5, especially 0.8 ≤ h ≤ 1.2, and especially 0.9 ≤ h ≤ 1.1. Preferably, the following applies: h = 1.

[0055] The supply opening has a length L in the conveying direction. Z The following applies specifically to length L. Z H(x1)≤L Z ≤2·H(x1), especially 1.2·H(x1)≤L Z ≤1.5·H(x1).

[0056] The feed screw compressor according to claim 9 ensures better material feeding into the processing screw compressor. The first housing portion 6 includes a feed opening, while the second housing portion 6 includes a feed opening. At least two housing portions allow for simple and flexible adjustment of the housing length L. G Because the outer shell has a larger length L G At least two screw shafts also have a greater length L. The compression of the material during conveying can be easily and flexibly adjusted via the length L of the at least two screw shafts.

[0057] At least two housing parts are arranged sequentially in the conveying direction and connected to each other to form a finished housing part 6 connected to the processing screw press.

[0058] The feed screw mill according to claim 10 ensures better material feeding into the processing screw mill. Since the shafts of each screw shaft are integrally formed with at least one associated screw element, at least two screw shafts can be manufactured in a simple manner such that the free volume V(x) is reduced in a desired manner in the conveying direction. The at least two screw shafts also have high rigidity. Each of the at least two screw shafts can contain at least one processing element, particularly at least one screw element and / or at least one kneading element, which is formed as two parts with and reversibly connected to the associated shaft. Therefore, for example, processing elements subjected to significant wear can be easily replaced. Moreover, the at least two screw shafts can be adapted in a simple manner to accommodate materials and / or desired material conveying and / or compression. For example, the at least two screw shafts can include processing elements with blades that crush the conveyed material. Preferably, each of the at least two screw shafts includes at least one kneading block having a plurality of disc-shaped kneading elements integrally connected to each other. No free volume is defined in the region of at least one kneading element of each screw shaft.

[0059] The feed screw compressor according to claim 11 ensures better material feeding into the processing screw compressor. At least one degassing device is specifically connected to the housing and / or the feed hopper. The at least one degassing device is specifically used to remove air during material feeding into at least two housing orifices and / or during material compression in at least two housing orifices. This simplifies and improves the filling and / or compression of the material in the at least two housing orifices in the feed opening area. In particular, the conveying efficiency or throughput of the feed screw compressor is improved. Preferably, the feed screw compressor includes components sequentially formed in the housing in the feeding direction.

[0060] Multiple degassing openings are provided. These openings are preferably formed on the lower and / or upper side of the housing. Specifically, individual degassing inserts are arranged within the degassing openings. Each degassing opening is connected to at least one degassing device. The at least one degassing device includes individual suction lines connected to the respective degassing openings and a suction unit for generating negative pressure. Each degassing opening has a free degassing area A. E The following applies to the free degassing area A. E Same average screw outer diameter D am The ratio of squares: 0.3 ≤ A E / D am 2 ≤6, especially 0.8≤A E / D am 2 ≤4.5, and especially 1.3≤A E / Dam 2 ≤3.5.

[0061] The following applies specifically to the average screw outer diameter D. am : in

[0062] D a (x1) represents the outer diameter of the screw at the delivery point x1 corresponding to the beginning of the screw shaft of the at least two screw shafts, and

[0063] D a (x3) indicates the outer diameter of the screw at the delivery point x3 corresponding to the end of the screw shaft of the at least two screw shafts.

[0064] The supply opening has a cross-sectional area A. Z The following are particularly applicable to supplying openings with a cross-sectional area of ​​A. Z Same average screw outer diameter D am The ratio of squares: 2 ≤ A Z / D am 2 ≤7, especially 2.5≤A Z / D am2 ≤5.5, especially 3≤A Z / D am 2 ≤4.5.

[0065] The feed screw compressor according to claim 12 ensures better material feeding into the processing screw compressor. The compression of the material forces liquid out of it. Before the liquid enters the processing screw compressor, it can be discharged from at least two housing openings via at least one discharge opening. The at least one discharge opening is arranged between the feed opening and the feed opening, preferably close to the feed opening. At least one discharge opening is formed on the bottom surface of the housing, allowing liquid to drain from at least two housing openings due to gravity. Therefore, at least one discharge opening enables dehumidification of the material in a simple manner.

[0066] The present invention is further based on the purpose of creating a processing device that can process materials with low bulk density in a simple and economical manner.

[0067] This objective is achieved by a processing apparatus having the features described in claim 13. The advantages of the processing apparatus according to the invention correspond to the advantages of the feed screw compressor according to the described invention. This processing apparatus can be further specifically implemented having at least one feature described with reference to claims 1 to 12.

[0068] Because the feed screw compressor draws in a relatively large amount of material and compresses it during conveying in the conveying direction, it achieves a high throughput when it reaches the processing screw compressor. This provides the processing screw compressor with a large amount of compressed material that can be easily absorbed. Therefore, the processing screw compressor can operate economically with high fill rates and high throughput.

[0069] The feed screw is preferably designed as a side-feed screw, which is laterally connected to the processing screw.

[0070] The processing screw compressor includes a housing having at least one housing bore. Associated processing element shafts are rotatably arranged in at least one housing bore for processing the supplied material. The processing screw compressor is preferably designed as a multi-screw compressor. Preferably, at least two housing bores are formed in the housing, penetrating each other and having a horizontal V-shaped cross-section. At least two associated processing element shafts are rotatably arranged in at least two housing bores and can preferably be driven to rotate in the same direction of rotation. The at least two processing element shafts are preferably designed to mesh tightly with each other. A material supply opening for supplying compressed material is formed in the housing, communicating with the feed opening of a feed screw compressor. The material supply opening is supplied with the material to be processed by the feed screw compressor. Preferably, the material supply opening of the processing screw compressor is formed laterally. The material supply opening corresponds in cross-section to the feed opening. At least two screw shafts preferably extend through the feed opening and project outside the housing. The projecting portions of the at least two screw shafts preferably open into the material supply opening and extend into at least two connecting holes, such that compressed material is conveyed into at least one housing bore of the processing screw compressor. At least two connecting holes extend at least two housing holes of the feed screw and specifically define, with at least two screw shafts, a free cross-sectional area that preferably decreases monotonically.

[0071] At least one processing element shaft of the screw press has an outer diameter D A and inner diameter D I The following applies in particular to the ratio D. A / D I 1.5≤D A / D I ≤1.8.

[0072] Applicable to ratio D: in

[0073] D a (x3) represents the outer diameter of the screw at the delivery point x3 corresponding to the end of the screw shaft of the at least two screw shafts, and

[0074] D i (x3) describes the screw inner diameter of at least two screw shafts at the conveying point x3.

[0075] For the ratio D, the following applies in particular: 0.66 ≤ D ≤ 1.61, and especially 0.94 ≤ D ≤ 1.48.

[0076] The processing apparatus according to claim 14 ensures simple and economical operation. Due to the screw outer diameter D... a The feed screw has a relatively large free cross-sectional area A(x1), which allows a large amount of material to be fed into the processing screw in a compressed form.

[0077] The processing apparatus according to claim 15 ensures simple and economical operation. The relatively large screw outer diameter D... a (x3) Ensure that compressed material is supplied to the processing screw in a simple and reliable manner at the desired throughput, and ensure that the latter can suck in the compressed material.

[0078] The present invention is further based on the objective of creating a method for processing apparatuses with low bulk density materials that can be operated in a simple and economical manner.

[0079] This objective is achieved by a method having the features described in claim 16. The advantages of the method according to the invention correspond to the advantages of the feed screw according to the invention and the processing apparatus according to the invention, which have already been described. The method according to the invention can be particularly further implemented having at least one feature described in the context of claims 1 to 15.

[0080] This material has a bulk density ρ. The following is particularly applicable to bulk densities ρ: 5 g / dm³ 3 ≤ρ≤600g / dm 3 Especially 10g / dm 3 ≤ρ≤250g / dm 3 Especially 15g / dm 3 ≤ρ≤200g / dm 3 Especially 20g / dm 3 ≤ρ≤100g / dm 3 The material has a maximum material size a. max In particular: 1mm≤a max ≤50mm, especially 5mm≤a max ≤35mm, especially 10mm≤a max ≤20mm.

[0081] The material is preferably a foil material. The foil material has a foil thickness t. The following are particularly applicable to foil thicknesses t: 10μm≤t≤400μm, especially 15μm≤t≤300μm, especially 20μm≤t≤200μm.

[0082] The material preferably includes recycled materials and / or fillers, such as powdered fillers and / or reinforcing materials or reinforcing fibers and / or fiber particles.

[0083] For example, recycled materials may be in the form of fragments, flakes, and / or granules. For example, recycled materials may be waste foil.

[0084] The feed screw compressor operates at a speed n, with the following being particularly applicable: 50 rpm ≤ n ≤ 1000 rpm, especially 100 rpm ≤ n ≤ 800 rpm, and especially 200 rpm ≤ n ≤ 600 rpm. The feed screw compressor further operates at a torque M per screw shaft. d The following applies in particular to torque M. d The ratio of the distance to each center distance a(x1) is 0.1 Nm / cm. 3 ≤M d / a(x1) 3 ≤0.8Nm / cm 3 Especially 0.15 Nm / cm 3 ≤M d / a(x1) 3 ≤0.5Nm / cm 3 And especially 0.2 Nm / cm 3 ≤M d / a(x1) 3 ≤0.35Nm / cm 3 .

[0085] a(x1) represents the center distance of the rotation axes associated with at least two screw shafts at the delivery point x1 corresponding to the beginning of the screw shafts.

[0086] The feed screw compressor is specifically designed for dimensionless throughput. in

[0087] Indicates the volumetric flow rate of the material supplied to the feed screw.

[0088] n indicates the rotational speed of at least two screw shafts, and

[0089] D a (x1) indicates the screw outer diameter of at least two screw shafts at the delivery point x1 corresponding to the beginning of at least two screw shafts.

[0090] The following applies in particular to throughput Φ: 0.1≤Φ≤1.2, especially 0.25≤Φ≤1, especially 0.3≤Φ≤0.8. Attached Figure Description

[0091] Further features, advantages, and details of the present invention will become apparent from the description of the following embodiments, wherein:

[0092] Figure 1 A side view of a processing apparatus having a processing screw and a feeding screw according to a first embodiment is shown.

[0093] Figure 2 It shows Figure 1Top view of the processing device in the middle.

[0094] Figure 3 The example shown is without the screw compressor. Figure 1 Side view of the feed screw compressor in the middle.

[0095] Figure 4 It shows Figure 3 A top view of the feed screw compressor in the middle.

[0096] Figure 5 It shows along Figure 2 The cross-section line VV passes through the longitudinal sections of the processing screw and the feed screw.

[0097] Figure 6 It shows along Figure 5 The section line VI-VI passes through the cross-sections of the processing screw and the feed screw.

[0098] Figure 7 It shows the direction along the beginning of the screw shaft. Figure 3 Section line VII-VII passes through the longitudinal section of the feed screw compressor.

[0099] Figure 8 It shows along one end of the casing Figure 3 Section line VIII-VIII passes through the longitudinal section of the feed screw compressor.

[0100] Figure 9 The graph shows the functional relationship between the throughput of the feed screw compressor and the rotational speed of different materials.

[0101] Figure 10 A longitudinal section of the inlet hopper region of the feed screw compressor according to the second embodiment is shown. Detailed Implementation

[0102] The following reference Figures 1 to 9 The first embodiment of the present invention is described. Figure 1 and Figure 2 The processing apparatus 1 shown includes a processing screw 2, a first feed screw 3 for supplying low bulk density material M to the processing screw 2, and a second feed screw 4 for supplying additive Z to the processing screw 2.

[0103] The processing screw compressor 2 includes a housing 5 having a plurality of housing portions 6 to 16 arranged front to back. The housing portions 6 to 16 are joined together to form the housing 5. The processing screw compressor 2 is designed as a multi-screw compressor. Two housing bores 17 and 18 are formed in the housing 5, which are parallel to each other and penetrate each other, and their cross-sections are horizontally V-shaped. Two processing element shafts 19 and 20 are concentrically arranged in the housing bores 17 and 18, and they are driven by an electric drive motor 21 to rotate about associated rotation axes 22 and 23. A branch gear 24 is arranged between the processing element shafts 19 and 20 and the drive motor 21. A coupling 25 is then arranged between the drive motor 21 and the branch gear 24. The processing element shafts 19 and 20 are driven by the drive motor 21 in the same direction, i.e., in the same direction of rotation about rotation axes 22 and 23.

[0104] The screw press 2 has an inlet zone 27, a plasticizing zone 28, a second inlet zone 29, a homogenizing zone 30 and a discharge zone 31 in the processing direction 26.

[0105] In the first inlet zone 27, the base material B to be processed is supplied to the processing screw 2. For this purpose, a first material supply opening 32 is formed in the outer casing 6. A hopper 3 is arranged on the outer casing 6, which leads to the first material supply opening 32. For example, the base material B is a granular plastic material. In the processing direction 26 downstream of the first material supply opening 32, material M is supplied to the processing screw 2. For example, material M is a recycled material. For this purpose, a second material supply opening 34 is formed in the outer casing 68. The second material supply opening 34 is formed laterally. A connecting hole extends laterally from the second material supply opening 34 through the outer casing 68 and leads to the outer casing hole 17. Material M can also be supplied exclusively through the second material supply opening 34 in the first inlet zone 27, without supplying any base material B through the first material supply opening 32. In this case, venting can be performed using the first material supply opening 32. The second material supply opening 34 can also be formed in the outer casing 6 or 7.

[0106] Base material B and material M are conveyed to plasticizing zone 28 and melted there into a material melt. The processing screw 2 includes degassers 35 and 36, which are arranged in the plasticizing zone 28 on the housing 10 and 11 and connected to the corresponding degassing openings in the housing 10 and 11.

[0107] The molten material is conveyed to the second inlet zone 29. In the second inlet zone 29, additive Z is supplied to the molten material. For this purpose, a third material supply opening, not shown in more detail, is formed in the outer casing 613. The third material supply opening extends laterally through the outer casing 613 and leads to the outer casing hole 17. The second feed screw 4 has a common design and is not described in more detail. The second feed screw 4 is laterally connected to or attached to the outer casing 613. In the second inlet zone 29, a degasser 37 is arranged on the outer casing 613, leading to a degassing port, not shown in more detail.

[0108] The material melt, together with additive Z, is conveyed to the homogenization zone 30. In the homogenization zone 30, the material melt and additive Z are mixed and homogenized.

[0109] In discharge zone 31, the molten material supplied along with additive Z is discharged. Nozzle plate 38 is arranged on the last housing portion 616, forming a discharge opening not shown in more detail.

[0110] To form the first entry zone 27, the plasticizing zone 28, the second entry zone 29, the homogenizing zone 30, and the discharge zone 31, the processing element shafts 19 and 20 typically include processing elements 39 and 40, which are rotatably fixed on the associated shafts 41 and 42. The processing elements 39 and 40 are designed as screw elements and / or kneading elements. Preferably, the kneading elements are designed as kneading discs, thereby, in particular, multiple kneading discs are connected as a single unit to form a kneading block. The processing element shafts 19 and 20 have an outer diameter D. A and inner diameter D I Specifically, the following applies: 1.5 ≤ D A / D I ≤1.8.

[0111] The first feed screw compressor 3 is designed as a dual-shaft side-feed screw compressor. The feed screw compressor 3 includes a housing 43 having two housing portions 44 and 45. The housing portions 44 and 45 are arranged sequentially in the conveying direction 46 and connected to each other to form the housing 43. Two housing holes 47 and 48 are formed in the housing 43, penetrating each other and forming a horizontal V-shape in cross-section. Two screw shafts 49 and 50 are respectively arranged in the housing holes 47 and 48, and they can be driven by an electric drive motor 52 via an angular branch gear 51 to rotate in the same direction around associated rotation axes 53 and 54.

[0112] The feed screw compressor 3 includes a connecting housing 55 that connects housing 43 to an angular branch gear 51. The connecting housing 55 is also referred to as a gearbox lantern. The two output shafts 56, 57 of the angular branch gear 51 extend into the connecting housing 55.

[0113] Screw shafts 49 and 50 each include screw elements 58 and 59, which are integral with the corresponding shafts 60 and 61. The ends of shafts 60 and 61 extend into the coupling housing 55 and are connected to output shafts 56 and 57 via coupling sleeves 62 and 63. To seal shafts 60 and 61, the feed screw compressor 3 includes packing glands 70 and 71 attached to the coupling housing 55.

[0114] The feed screw compressor 3 includes a movable frame 64, a connecting housing 55, and thus an angular branch gear 51 attached to the movable frame 64 with a drive motor 52 connected thereto and the housing 43.

[0115] The feed screw compressor 3 includes a feed opening 65 and a feed opening 66. The feed opening 65 is formed in the first housing portion 644. The feed screw compressor 3 includes a feed hopper 67 leading to the feed opening 65. The feed opening 65 is formed on the upper side of the first housing portion 644 and leads to the housing holes 47 and 48 via a feed chute. The feed opening 65 has a length L in the conveying direction 46. Z And has a free supply opening cross-sectional area A Z .

[0116] A feed opening 66 is formed at the end of the second housing portion 645 facing the processing screw 2. The feed opening 66 is formed and arranged in accordance with the second material supply opening 34. The screw shafts 49 and 50 extend over the feed opening 66 and lead to the second material supply opening 34. Therefore, the feed opening 66 is used to supply material M into the processing screw 2.

[0117] A discharge opening 68 is formed in the second housing portion 645 for discharging liquid. The discharge opening 68 is disposed on the lower side of the second housing portion 645. The discharge opening 68 can be closed by a closing element 69.

[0118] The conveying direction 46 defines the x-axis. The x-axis originates from the screw shaft beginning 72 of screw shafts 49 and 50. The origin or screw shaft beginning 72 is hereinafter referred to as conveying point x1. The housing end 73 of housing 43 is hereinafter referred to as conveying point x2. Furthermore, the screw shaft end 74 of screw shafts 49 and 50 is hereinafter referred to as conveying point x3. Perpendicular to the x-axis, the relevant cross section E(x) is generally defined at random conveying points as x1≤x≤x3. The x-axis and example cross section E(x) are shown below. Figure 6 As shown.

[0119] Screw shafts 49 and 50 are conical in design and conically arranged within the corresponding housing bores 47 and 48. Rotation axes 53 and 54 form an angle α, where: 0° < α ≤ 45°, particularly 1° ≤ α ≤ 20°, and particularly 2° ≤ α ≤ 10°. Output shafts 56 and 57 form an angle β in a corresponding manner, where: β = α.

[0120] Screw shafts 49 and 50 have multiple threads N, where N = 2. Therefore, screw shafts 49 and 50 are formed by two threads. To increase the free cross-sectional area A(x) between the housing 43 and the screw shafts 49 and 50 in their respective cross-sections E(x), screw shafts 49 and 50 have threads on their respective effective tooth surfaces F. A and their respective passive tooth surfaces F P It has a thrust edge profile. Each has its own effective tooth surface F. A With tooth lateral angle γ A Correspondingly, their respective passive tooth surfaces F P With tooth lateral angle γ P Tooth lateral angle γ A and / or tooth lateral angle γ P The conveying direction 46 can be constant or variable, especially increased. Due to the double-thread design, the screw shafts 49 and 50 each have two threaded ridges 75 and 76 in their respective cross-sections E(x). Each threaded ridge 75 and 76 is located at the tip of its respective thread tooth, i.e., at the outer diameter D of the screw. a At point (x), each screw has its own inclination in its respective cross-section E(x). The inclinations of screw edges 75 and 76 differ slightly from each other due to angle α. The inclination S(x) of screw shafts 49 and 50 is defined as the average inclination of screw edges 75 and 76 in their respective cross-sections E(x). The inclination S(x) decreases strictly monotonically in the conveying direction 46. The inclination S(x) is generally as follows: Figure 6 As shown. The tilt angle S(x) defines the pitch H(x) for each cross section E(x). The pitch H(x) is a nominal value associated with the tilt angle S(x) in the cross section E(x). Since the tilt angle S(x) decreases strictly monotonically in the conveying direction 46, the pitch H(x) is greater than the actual pitch of the screw shafts 49 and 50. The pitch H(x) is defined as one revolution of the tilt angle S(x).

[0121] The free cross-sectional area A(x) and the corresponding pitch H(x) define the free volume V(x) of the cross-section E(x), where: V(x) = A(x)·H(x). Due to the conical design and the strictly monotonically decreasing pitch H(x) in the conveying direction 46, the free volume V(x) decreases strictly monotonically in the conveying direction 46. Because the free cross-sectional area A(x) and pitch H(x) decrease strictly monotonically in the conveying direction 46, the material M is compressed in the conveying direction 46 and is laterally compressed in the conveying direction 46 during conveying.

[0122] Screw shafts 49 and 50 have an outer diameter D in their respective cross-sections E(x). a (x) and the relevant screw inner diameter D i (x), which decrease strictly monotonically in the conveying direction 46. For D a (x) / Di (x), the following applies in particular: 1.55 ≤ D a (x) / D i (x)≤2.5, especially 1.8≤D a (x) / D i (x)≤2.2. Preferably, D a (x) / D i (x) is a constant in the transport direction 46.

[0123] The outer casing holes 47 and 48 have an outer casing hole diameter D in their respective cross-sections E(x). G (x), which decreases strictly monotonically in the conveying direction 46. Relative gap It is constant in the conveying direction 46 and / or increases in the conveying direction 46.

[0124] The following is particularly applicable to the ratio of pitch H(x) to screw outer diameter Da(x): 1 <H(x) / D a (x)≤2, especially 1.2≤H(x) / D a H(x) ≤ 1.5. a The ratio of (x) is constant, especially in the transport direction 46.

[0125] Figure 3 and Figure 6 The cross-sections E(x1) at conveying point x1, E(x2) at conveying point x2, and E(x3) at conveying point x3 are shown. Figure 7 The feed screw compressor 3 is shown in cross-section E(x1), while Figure 8 The feed screw compressor 3 is shown in cross section E(x2).

[0126] In cross section E(x1), screw shafts 49 and 50 have an outer diameter D. a (x1) and screw inner diameter D i (x1). The center distance between the rotation axes 53 and 54 is a(x1). The outer casing holes 47 and 48 have an outer casing hole diameter D. G (x1). The screw shafts 49 and 50, together with the housing 43, define the free cross-sectional area A(x1) of the housing holes 47 and 48.

[0127] Screw edges 75 and 76 have an inclination S(x1) in the cross section E(x1), which defines a pitch H(x1) of rotation. With respect to the cross section E(x1), the following applies to the first free volume V(x1): V(x1) = A(x1)·H(x1).

[0128] In the cross section E(x2) at the conveying point x2 or the end of the housing 73, the screw shafts 49 and 50 have a screw outer diameter D. a(x2) and the inner diameter D of the screw i (x1). The rotational axes 53, 54 have a center distance a (x2). The housing bores 47, 48 have a housing bore diameter D G (x2). The housing bores 47, 48 and the screw shafts 49, 50 define a free cross-sectional area A (x2). The screw threads 75, 76 have an inclination S (x2) in the cross-section E (x2), which defines a rotational pitch H (x2). With respect to the cross-section E (x2), the following applies to the second free volume V (x2): V (x2) = A (x2) · H (x2).

[0129] In the cross-section E (x2), the screw shafts 49, 50 have an outer screw diameter D a (x3) and an inner screw diameter D i (x3). The screw threads 75, 76 have an inclination S (x3) in the cross-section E (x3), which defines a rotational pitch H (x3). For the average outer screw diameter D am , the following applies:

[0130] For the compression V (x1) / V (x2), in particular: 1 < V (x1) / V (x2) ≤ 20, especially 2 ≤ V (x1) / V (x2) ≤ 15, and especially 4 ≤ V (x1) / V (x2) ≤ 10.

[0131] For the ratio A (x1) / A (x2), in particular: 1 < A (x1) / A (x2) ≤ 8, especially 1.5 ≤ A (x1) / A (x2) ≤ 7, especially 2 ≤ A (x1) / A (x2) ≤ 6.

[0132] For the ratio H (x1) / H (x2), in particular: 1 < H (x1) / H (x2) ≤ 8, especially 1.1 ≤ H (x1) / H (x2) ≤ 5, especially 1.2 ≤ H (x1) / H (x2) ≤ 3.

[0133] For the ratio In particular: 0.62 ≤ d ≤ 1.22, especially 0.82 ≤ d ≤ 1. Optimal: d = 1.

[0134] For the ratio In particular: 0.5 ≤ h ≤ 1.5, especially 0.8 ≤ h ≤ 1.2, particularly 0.9 ≤ h ≤ 1.1. Optimal: h = 1.

[0135] The screw shafts 49, 50 have a length L in the conveying direction 46. For the taper In particular: 0.05≤K≤1, especially 0.1≤K≤0.9, especially 0.15≤K≤0.8, especially 0.2≤K≤0.7, especially 0.25≤K≤0.6, especially 0.3≤K≤0.4.

[0136] For the ratio D a (x1) / D a (x3), in particular: 1≤D a (x1) / D a (x3)≤4, especially 1.2≤D a (x1) / D a (x3)≤3, especially 1.3≤D a (x1) / D a (x3)≤2.5.

[0137] The screw inner diameter D of at least two screw shafts i (x) is constant or monotonically decreasing or strictly monotonically decreasing in the direction of transport, at least in some regions.

[0138] For at least two screw shafts at the delivery point x1, the screw inner diameter D i The ratio of (x1) to the screw inner diameter D1(x3) of at least two screw shafts at the delivery point x3, with particular application as follows: 1≤D i (x1) / D1(x3)≤5, especially 1.25≤D i (x1) / D1(x3)≤4, especially 1.5≤D i (x1) / D1(x3)≤3.

[0139] The smaller the taper K, the larger the length L. If the length L is too large, a large leverage force acts on at least two screw shafts, which will put great stress on the bearings used to support at least two screw shafts on the housing or gearbox bearings. In addition, if the length L of at least two screw shafts is too large, the production of the feed screw mill is uneconomical.

[0140] A larger taper K corresponds to a smaller length L. If the length L is too small, the conveying efficiency of at least two screw shafts will be poor.

[0141] The length L is specifically the distance between conveying points x1 and x3. The following applies in particular to length L: 0.3m ≤ L ≤ 4m, especially 0.5m ≤ L ≤ 3.5m, especially 0.7m ≤ L ≤ 3m, especially 0.9m ≤ L ≤ 2.5m.

[0142] In the axial section, the envelope of each screw shaft forms an angle with the associated axis of rotation, particularly at least 2 degrees and at most 10 degrees, particularly at least 2.5 degrees and at most 8 degrees, particularly at least 3 degrees and at most 6 degrees. The envelope of each screw shaft is defined by the screw outer diameter at each delivery point.

[0143] For the outer shell 43, the outer shell length L G With screw outer diameter D a The ratio of (x1) is preferably applicable if: 2 ≤ L G / D a (x1)≤15, especially 3≤L G / D a (x1)≤10, especially 4≤L G / Da(x1)≤6.

[0144] For the ratio D a (x1) / D A In particular: 1≤D a (x1) / D A ≤4, especially 1.5≤D a (x1) / D A ≤3, especially 1.8≤D a (x1) / D A ≤2.5.

[0145] Furthermore, for the ratio D a (x3) / D A Specifically applicable to the following: 1≤D a (x3) / D A ≤1.5, especially 1.1≤D a (x3) / D A ≤1.4, especially 1.2≤D a (x3) / D A ≤1.3.

[0146] For ratio Specifically: 0.66≤D≤1.61, especially 0.94≤D≤1.48.

[0147] The feed screw compressor 3 includes a temperature control device 77. The temperature control device 77 is used to heat and / or cool the housing 43. The temperature control device 77 includes a fluid passage 78 formed in the first housing portion 644. The fluid passage 78 is connected to a fluid pump (not shown in more detail). The fluid passage 78 is used to receive a temperature-controlled fluid. The temperature-controlled fluid can be heated and / or cooled in a conventional manner by means of a temperature control unit (not shown in more detail). For example, the temperature-controlled fluid is water.

[0148] The feed screw compressor 3 includes a degassing device 79. The degassing device 79 includes three degassing inserts 80, 81, and 82, which are inserted into corresponding degassing openings 83, 84, and 85 in the first housing portion 644. The degassing device 79 is as follows... Figure 5 As shown.

[0149] A first degassing opening 83 is formed on the lower side of the first housing portion 644 and faces the supply opening 65. A second degassing opening 84 and a third degassing opening 85 are formed in the first housing portion 644 downstream of the first degassing opening 83 in the conveying direction 46. The second degassing opening 84 is arranged on the lower side, while the third degassing opening 85 is formed on the upper side opposite to the second degassing opening 84. Degassing inserts 80, 81, and 82 are connected to the suction unit 92 via respective suction lines 86, 87, and 88 and via respective valves 89, 90, and 91. The volumetric flow rate in each suction line 86, 87, and 88 can be adjusted via valves 89, 90, and 91.

[0150] Each degassing opening 83, 84, and 85 has a free degassing area A. E For the free degassing area A E Same average screw outer diameter D am The ratio of squares, especially applicable when: 0.3 ≤ A E / D am 2 ≤6, especially 0.8≤A E / D am 2 ≤4.5, and especially 1.3≤A E / D am 2 ≤3.5.

[0151] Preferably, the free degassing area A of the first degassing opening 83 is... E The free degassing area A is greater than the degassing openings of 84 and 85. E .

[0152] The following is particularly applicable to length L of a 65-degree opening. Z H(x1)≤L Z ≤2·H(x1), especially 1.2·H(x1)≤L Z ≤1.5·H(x1).

[0153] For the supply opening cross-sectional area A Z Same average screw outer diameter D am The ratio of squares, especially applicable when 2 ≤ A Z / D am 2 ≤7, especially 2.5≤A Z / D am2 ≤5.5, and especially 3≤A Z / D am 2 ≤4.5.

[0154] The functional principle and operation instructions of processing device 1 are as follows:

[0155] In the first entry zone 27, base material B is supplied via the first material supply opening 32, and material M is supplied via the second material supply opening 34 into the outer shell openings 17 and 18. For example, base material B is in granular form. For example, material M, a recycled material, is mixed with base material B. Material M has a bulk density ρ, where: 5 g / dm³ 3 ≤ρ≤600g / dm 3 Especially 10g / dm 3 ≤ρ≤250g / dm 3 Especially 15g / dm 3 ≤ρ≤200g / dm 3 Especially 20g / dm 3 ≤ρ≤100g / dm 3 For example, material M exists in the form of fragments, flakes, and / or granules. Material M has a maximum size a. max Where: 1mm≤a max ≤50mm, especially 5mm≤a max ≤35mm, and especially 10mm≤a max ≤20mm. For example, material M is a foil material with a foil thickness of t, wherein: 10μm≤t≤400μm, particularly 15μm≤t≤300μm, particularly 20μm≤t≤200μm.

[0156] Material M is supplied to processing screw 2 via first feed screw 3. For this purpose, material M is supplied to housing holes 47 and 48 of feed screw 3 via feed hopper 67 and supply opening 65.

[0157] Material M is conveyed in the conveying direction 46 by means of screw shafts 49 and 50. For this purpose, screw shafts 49 and 50 are driven to rotate in the same direction by means of an electric drive motor 52 via angular branch gears 51. Since both the free cross-sectional area A(x) and the pitch H(x) decrease strictly monotonically in the conveying direction 46, the free volume V(x) also decreases strictly monotonically in the conveying direction 46. When conveyed, material M is therefore compressed in the conveying direction 46 and laterally compressed into the conveying direction 46. Since the local derivatives of the free cross-sectional area A(x), the pitch H(x), and the free volume V(x) are continuous in the conveying direction 46, i.e., they do not jump, compression occurs continuously in a simple and reliable manner. The local processes of the free cross-sectional area A(x), the pitch H(x), and the free volume V(x) are as follows: Figure 6 As shown.

[0158] Air that escapes from material M due to compression is drawn out via degassing device 79. The flow rates of each volume in suction lines 86, 87, and 88 can be adjusted as needed via valves 89, 90, and 91. The heat generated by compression can be removed from housing 43 by means of temperature control device 77.

[0159] Material M is dehumidified by compression, causing the liquid to accumulate in the outer shell holes 47 and 48. The liquid can be discharged through the discharge opening 68.

[0160] The compressed material M is supplied to the housing holes 17 and 18 through the feed opening 66 and the connecting hole of the housing part 68. The connecting hole formed in the housing part 68 continues to the housing holes 47 and 48 until the screw shaft end 74 or the housing holes 17 and 18.

[0161] Screw shafts 49 and 50 are driven by a drive motor 52 and an angular branch gear 51 at a rotational speed n and torque M per screw shaft 49 and 50. d Driven by rotation. The following applies particularly to rotational speeds n: 50 rpm ≤ n ≤ 1000 rpm, especially 100 rpm ≤ n ≤ 800 rpm, and especially 200 rpm ≤ n ≤ 600 rpm.

[0162] For the ratio M d / a(x1) 3 Specifically: 0.1 Nm / cm 3 ≤M d / a(x1) 3 ≤0.8Nm / cm 3 Especially 0.15 Nm / cm 3 ≤M d / a(x1) 3 ≤0.5Nm / cm 3 Especially 0.2 Nm / cm 3≤M d / a(x1) 3 ≤0.35Nm / cm 3 .

[0163] Because the feed screw 3 has a large free cross-sectional area A(x1) in the region of the supply opening 65, a relatively large amount of material M can be supplied to the feed screw 3. The material M is then compressed in the manner described above during conveying, which allows the processing screw 2 to easily and reliably draw the compressed material M into the first inlet zone 27. Regarding the dimensionless throughput of the feed screw 3... The following applies in particular: 0.1≤Φ≤1.2, especially 0.25≤Φ≤1, and especially 0.3≤Φ≤0.8. This indicates the volumetric flow rate of material M supplied to the feed screw compressor 3.

[0164] Base material B and material M are conveyed along the processing direction 26 to the plasticizing zone 28, where they are melted to form a material melt. Any escaping gases can be removed via degassers 35 and 36. In the second inlet zone 29, additive Z is typically supplied to the material melt, which is uniformly mixed in the homogenization zone 30. Any escaping gases can be removed sequentially via degasser 37. The material melt supplied along with additive Z is then discharged through nozzle openings in the outlet zone 31.

[0165] Figure 9 The graph shows the throughput of the feed screw compressor 3 in kg / h as a function of the rotational speed n in rpm for different materials M1, M2, and M3. Material M1 has a bulk density ρ1 = 37 g / dm³ 3 Material M2 has a bulk density ρ2 = 41 g / dm³ 3 Furthermore, material M3 has a bulk density ρ3 = 16 g / dm³ 3 In comparison, a conventional feed screw compressor with a maximum rotational speed of n = 600 rpm for material M1 has a maximum throughput of 100 kg / h, material M2 has a maximum throughput of 160 kg / h, and material M3 has a maximum throughput of 70 kg / h.

[0166] The following reference Figure 10 A second embodiment of the invention is described. In contrast to the first embodiment, the feed screw 3 includes a split feed hopper 67. The feed hopper 67 has a partition 93, thus forming a degassing channel 94 within the feed hopper 67. The degassing channel 94 is connected to another degassing device 79 via a suction line 95. Air escaping during material M supply can be directly removed via the suction channel 94. Further details regarding the construction and operating principles of the processing device 1 and the feed screw 3 can be found in the preceding embodiments.

Claims

1. A feeding screw for feeding material into a processing screw compressor, comprising: -Outer shell (43) - At least two outer casing holes (47, 48) are formed in the outer casing (43) and penetrate each other. - A supply opening (65) is formed in the housing (43) for supplying material (M) into the at least two housing openings (47, 48). - A feed opening (66), formed in the housing (43), is used to supply the material (M) to the processing screw (2), and - At least two screw shafts (49, 50) are rotatably arranged in the at least two housing holes (47, 48) for conveying the material (M) from the supply opening (65) to the feed opening (66) in the conveying direction (46). in, The at least two housing holes (47, 48) and the at least two screw shafts (49, 50) in their respective cross-sections (E(x)) define the free volume. ,in A(x) describes the free cross-sectional area in the cross-section (E(x)). H(x) describes the pitch of the screw shaft (49, 50) based on the inclination (S(x)) in the cross-section (E(x)), and X describes the conveying point in the conveying direction (46). as well as In order to continuously compress the material (M), the free volume V(x) decreases monotonically in at least some regions along the conveying direction (46). Its characteristic is that the tapering K= Defined as a tapered configuration of the at least two screw shafts (49, 50), where 0.05 ≤ K ≤ 1 applies, where D a (x1) indicates the outer diameter of the screw at the delivery point x1 corresponding to the beginning (72) of the screw shafts (49, 50) of the at least two screw shafts (49, 50). D a (x3) indicates the outer diameter of the screw at the delivery point x3 corresponding to the screw shaft ends (74) of the at least two screw shafts (49, 50), and L describes the length of the at least two screw shafts (49, 50). The at least two screw shafts (49, 50) define the screw outer diameter D in their respective cross-sections (E(x)). a (x) and screw inner diameter D i (x), where: 1.55 < D a (x) / D i (x) ≤ 2.

5.

2. The feed screw compressor according to claim 1, characterized in that, A first free volume V(x1) is defined in a first cross section (E(x1)) at a first conveying point x1 of the at least two screw shafts (49, 50), and a second free volume V(x2) is defined in a second cross section (E(x2)) at a second conveying point x2 of the at least two screw shafts (49, 50), the second conveying point x2 being located downstream of the first conveying point x1 in the conveying direction (46), wherein: 1 < V(x1) / V(x2) ≤ 20.

3. The feed screw compressor according to claim 1, characterized in that, The outer diameter (D) of the screws of the at least two screw shafts (49, 50) a (x) decreases at least within the region along the conveying direction (46).

4. The feed screw compressor according to claim 1, characterized in that, The aperture (D) of the at least two outer casing holes (47, 48) G (x) decreases at least within the region along the conveying direction (46).

5. The feed screw compressor according to claim 1, characterized in that, The rotation axes (53, 54) associated with the at least two screw shafts (49, 50) form an angle α, where: 0° < α ≤ 45°.

6. The feed screw compressor according to claim 1, characterized in that, For D a (x) / D i (x), applicable to: 1.8 ≤ D a (x) / D i (x) ≤ 2.2。 7. The feed screw compressor according to claim 1, characterized in that, The at least two screw shafts (49, 50) define the pitch H(x) and screw outer diameter D in their respective cross-sections (E(x)). a (x), where: 1 < H(x) / D a (x) ≤ 2.

8. The feed screw compressor according to claim 1, characterized in that, The outer casing (43) includes at least two outer casing portions (44, 45).

9. The feed screw compressor according to claim 1, characterized in that, Each of the at least two screw shafts (49, 50) includes a shaft (60, 61) and at least one screw element (58, 59), the shaft (60, 61) and the at least one screw element (58, 59) forming an integral unit with each other.

10. The feed screw compressor according to claim 1, characterized in that... Includes at least one degassing device (79).

11. The feed screw compressor according to claim 1, characterized in that, At least one discharge opening (68) is formed in the housing (43).

12. A processing apparatus having - Processing screw compressor (2), which is used to process material (M), and - A feed screw (3) for supplying the material (M) to the processing screw (2) according to claim 1.

13. The processing apparatus according to claim 12, characterized in that, The processing screw compressor (2) has an outer diameter of D. A At least one processing element shaft (19, 20). The at least two screw shafts (49, 50) have a screw outer diameter D in the cross section (E(x1)) at the delivery point x1 corresponding to the beginning of the screw shaft (72). a (x1), where: 1 ≤ D a (x1) / D A ≤ 4.

14. The processing apparatus according to claim 12, characterized in that, The processing screw compressor (2) has an outer diameter of D. A At least one processing element shaft (19, 20). The at least two screw shafts (49, 50) have a screw outer diameter D in the cross section (E(x3)) at the delivery point x3 corresponding to the end of the screw shaft (74). a (x3), where: 1 ≤ D a (x3) / D A ≤ 1.

5.

15. A method for operating a processing device, comprising the following steps: - Provides the processing apparatus (1) according to claim 12, and - The material (M) is fed through the feed opening (65) into at least two housing holes (47, 48) of the feed screw (3). - The material (M) is conveyed along the conveying direction (46) to the feed opening (66) and the material (M) is continuously compressed at least within a certain area during conveying. - The compressed material (M) is supplied to the processing screw compressor (2).

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