Spinning preparation machine

Abstract

The invention relates to a spinning preparation machine (1) for mixing fibers, comprising a removal device (25) for removing air from the spinning preparation machine (1) and a filling device for filling the spinning preparation machine (1) with fibers, wherein the spinning preparation machine (1) is designed as a chute mixer having at least two chutes (2-5). The filling device has a fiber material inlet (6) and a transport air outlet (8) and a distribution duct (11) which leads from the fiber material inlet (6) to the transport air outlet (8) via the at least two chutes (2-5). The distribution duct (11) and the transport air outlet (8) are separated by a perforated element (12) which is designed to have a convex shape when viewed in the direction of the transport air outlet (8).

Description

TECHNICAL FIELD

[0001] The invention relates to a spinning preparation machine for mixing fibers, comprising a removal device for removing fibers from the spinning preparation machine and a filling device for filling the spinning preparation machine with fibers. The spinning preparation machine is designed as a slide mixer with at least two mixing chambers, the filling device having a fiber material inlet and a transport air outlet with a transport air outlet duct and a distribution duct which leads from the fiber material inlet to the transport air outlet via the at least two mixing chambers. BACKGROUND

[0002] In a fiber preparation system of a spinning mill, supplied fibers or fiber clusters are prepared for use in a spinning machine. In the fiber preparation system, the fibers to be prepared for spinning are subjected to a plurality of processing stages. In a first stage, the fibers are removed from fiber bales in the form of fiber clusters. So-called bale breakers are usually used for this purpose. These fiber clusters are transported out of the bale breaker by means of pneumatic cluster conveying and are, for example, transferred to a downstream cleaning machine.

[0003] Downstream of the cleaning machine, the fiber clusters are usually transported to a mixer which, for example, ensures mixing of the fiber clusters by various slides. The fibers are then removed from the mixer via a removal device, for example by means of a spiked lattice, and continue to be transported. DE 37 13 5902 A1 discloses a mixer with a plurality of filling slides. These filling slides are filled simultaneously via a pneumatic transport system. By controlling the removal devices of the individual slides, thorough mixing of the fiber material is achieved.

[0004] EP 0 874 070 A1 also discloses a slide mixer with a plurality of slides. The fiber material is distributed to the various slides or chambers of the mixer by pneumatic conveying with the aid of transport air. The transport air is discharged from the chambers via gas-permeable side walls into a discharge duct.

[0005] The slide mixer is divided into various slides which are open at the upper side and are connected to a pneumatic conveying line. The incoming fiber clusters are distributed evenly to the various slides via a distributor. Downstream of the distributor, the slides first extend in the vertical direction, after which they are bent through 90° so that the slides or their cluster filling now extend in the horizontal direction. Their horizontal extension ends in a spiked lattice which essentially sweeps all the slides in the vertical direction from bottom to top and removes the fibers. This design of the mixer as a slide mixer ensures that the fibers are mixed as a result of the different lengths of the slides, i.e. the distances which the fibers have to cover, since the fibers which are fed to the mixer at different times and thus from different bales can be removed from the various slides simultaneously by the removal device. This construction type of the slide mixer has proved itself.

[0006] The disadvantage of this design is that the separation of the fibre material from the transport air is complex. Each chamber or each chute is provided with a gas-permeable wall, which also leads to a multiple risk of blockages. During operation, the gas permeability of the individual separating walls changes, which leads to different filling of the chutes due to the pressure conditions, which must be corrected by corresponding control of the distribution. SUMMARY

[0007] It is therefore the object of the present invention to create a device which provides a simple separation of the fibre material and the transport air and avoids different influences on the different filling levels of the mixer chutes by separating the transport air from the fibre in a chute-wise manner.

[0008] The problem is solved by a spinning preparation machine for mixing fibres according to the invention. In order to solve the problem, a new spinning preparation machine for mixing fibres is proposed, which comprises a removal device for removing air from the spinning preparation machine and a filling device for filling the spinning preparation machine with fibres. The spinning preparation machine is designed as a chute mixer with at least two chutes, the filling device has a fibre material inlet and a transport air outlet with a transport air outlet duct and a distribution duct which leads from the fibre material inlet to the transport air outlet via the at least two chutes. The distribution duct is separated from the transport air outlet by a perforated element. The perforated element is designed with a convex shape when viewed in the direction of the transport air outlet.

[0009] A transport duct is provided as a filling device through which the fibrous material is brought into the distribution duct together with the transport air as a fibre-air mixture. The distribution duct remains open towards the chute. Due to the flow being guided through the fibre material inlet, the transport air follows the distribution duct to the transport air outlet. The transport air outlet is arranged on the side opposite the fibre material inlet, so that the fibre-air mixture sweeps over the chute. Fibres or fibre clusters fall down into the chute. At the end of the distribution duct, a perforated element is installed as a curved element to separate the fibrous material from the transport air and thus the distribution duct from the transport air outlet duct. While the fibrous material remains open, the transport air penetrates through the perforations into the transport air outlet duct. The convex shape of the perforated element causes the fibre-air mixture to accelerate in the upper region of the distribution duct upstream of the perforated element, which promotes the automatic cleaning of the perforated element. It is also shown that the flow generated in the distribution duct and the resulting pressure conditions in the individual chutes due to the arrangement and shape of the perforated element both contribute to the uniform distribution of the fibres into the chutes. The positioning of the transport air outlet duct or the fibre material inlet relative to the machine longitudinal axis is irrelevant. The transport air outlet duct as well as the fibre material inlet can be provided both on the front of the machine and on the rear of the machine. This means that the machine can be ideally integrated into the existing fibre preparation system of a spinning mill.

[0010] The fibres extend through the individual chutes and are mixed by deflection and with the help of the removal device. The principle of the fibres flowing vertically and then horizontally through the chutes before reaching the removal device is known from the prior art. As a removal device, for example, a pin curtain can be used as an ascending conveyor, which on the one hand removes the fibres from the various chutes and on the other hand conveys the removed fibres into the fibre material outlet.

[0011] The chutes are advantageously surrounded by gas-tight chute walls. Since the separation of the transport air from the fibres is concentrated on the transition from the distribution duct to the transport air outlet duct and not uncontrolled via the individual chute walls, the chutes can be uniformly filled under constant flow and pressure conditions.

[0012] It is also advantageous that the distribution duct is surrounded on at least three sides by gas-tight duct walls. The efforts in earlier designs to separate part of the transport air to one side of the distribution duct according to the covered distance have proven to be disruptive. This is also due to the fact that the fibre-air mixture is not homogeneous and the load in the transport air with fibrous material is subject to constant fluctuations. The risk of clogging of the gas-permeable elements is also minimized, in particular also due to the foreseeable flow and pressure conditions and the central separation of the transport air and the fibres. Due to the prevailing flow conditions and pressure conditions in the chutes, the chutes are uniformly filled even without corresponding guide elements in the distribution duct, such as baffles or sheet metal.

[0013] The convex shape of the perforated element is preferably formed by flat sieve elements arranged in a row. As an alternative to perforated elements designed as circular segments, this is produced by arranging the flat sieve elements in a row. The individual sieve elements are joined together in such a way that the overall convex shape of the perforated element is produced. The individual sieve elements have corresponding perforations and are connected to one another, for example, by welding, gluing or screwing. In an alternative production method, the perforated element can be formed from a flat sheet metal by corresponding folding processes or by forming curved edges between the sieve elements. The curved edges are to be regarded as a restriction of the individual sieve elements. In comparison to production by rolling sheet metal to a large diameter, production of the perforated element can be simplified and made more cost-effective in this way. The narrower the individual sieve elements are designed, the closer the shape of the assembled or connected sieve elements approximates to a circular segment. If the perforated element consists of more than three sieve elements, the segmental construction of the convex perforated element has no decisive influence on the function or flow conditions of the perforated element.

[0014] The convex shape preferably corresponds to a circular segment with a radius in the range from 200 mm to 1,000 mm, particularly preferably in the range from 400 mm to 800 mm. The size of the radius to be selected depends on the size of the spinning preparation machine. This design of the perforated element leads to advantageous flow conditions which prevent the fibres from catching in the perforations. In order to achieve good air permeability and to avoid excessively high dynamic pressures, the perforated element preferably has a perforation of 20% to 50%. This means that at least 20% but not more than 50% of the surface is perforated, i.e. between 0.2 cm 2 and 0.5 cm 2 are provided per cm 2 of the perforated element. Too high a perforation would allow good fibres to pass through the holes or to catch in the holes and create attachment points.

[0015] The perforated element is advantageously divided into at least two regions which have different perforations. For example, the upper half of the perforated element is designed with a perforation of 28% and the lower half of the perforated element is designed with a perforation of 21%. Due to the resulting flow conditions, it is possible to make the pressure difference across the perforated element more uniform and to make the transport air separate more uniformly over the cross section of the perforated element. This design of the perforated element is advantageous in the case of a construction using sieve elements arranged in a row. More than two regions with different perforations are also conceivable. The individual sieve elements can easily be provided with different perforations.

[0016] Advantageously, the convex perforated element extends over an angle of more than 90 degrees. This increases the screen area and improves the flow conditions. The flow conditions upstream of the perforated element are also influenced in this way, so that no or only a small amount of transport air is discharged from the distribution duct through the convex shape of the perforated element into the last flight in front of the perforated element.

[0017] In a further development of the application, a cover element for setting a negative pressure in the transport air outlet duct is arranged on the side of the perforated element facing the transport air outlet. The cover element can be designed as a filter cloth or as a cover plate. The targeted partial covering of the perforations of the perforated element influences the pressure and flow conditions on the perforated element and enables a desired pressure difference to be set across the perforated element. As a result, the passage of air through the perforated element is made uniform. At the same time, when a filter cloth is used, the escaping transport air is kept free of large amounts of dust or fibre parts.

[0018] The perforations in the perforated element are advantageously formed by round or angular openings with a cross section of less than 0.1 cm 2 The small cross-sectional dimension of the individual openings in the perforations prevents or at least strictly limits the passage of reusable fibres through the perforated element into the transport air outlet duct.

[0019] The perforated element is preferably made of metal. Alternatively, the perforated element is made of a plastic material. When the perforated element is made of metal, a small thickness, for example less than 1 mm, can be chosen, which in turn leads to better cleaning due to the low edge height of the channel as a result of the flow through the perforated element. However, in the case of smaller dimensions of the flight mixer, it is also possible to use a perforated element made of a plastic material with sufficiently high stability and strength.

[0020] The air guide element is preferably arranged in the distribution duct above the flight partition wall between two flights. The air guide element is designed as an upper closure of the flight partition wall. The air guide element briefly accelerates the flow from the fibre material inlet to the transport air outlet, which leads to improved distribution of the fibre material on the flights. The air guide element is advantageously provided with a convex closure against the shape of the distribution duct in order to avoid adhesion of fibres.

[0021] Advantageously, the transport air outlet duct has a larger cross section than the perforated element. The transport air outlet duct is arranged in the shape of a hood at a distance around the perforated element. The distance between the wall of the transport air outlet duct and the perforated element is preferably greater than 100 mm. As a result, the flow is calmed down and the air passage of the transport air through the perforated element is made more uniform. Furthermore, a maintenance opening is preferably arranged in the transport air outlet duct in order to check the condition of the perforated element and to be able to clean the transport air outlet duct if necessary. At least a part of the maintenance opening is advantageously designed to be transparent.

[0022] In an alternative to the hood-like design of the transport air outlet duct, the transport air outlet duct advantageously has a first portion which is guided along the perforated element and a second portion which adjoins the first portion, the second portion being guided away from the perforated element. The design of the first portion of the transport air outlet duct is suitable for a convex perforated element, such that an arched duct is produced. The transport air flowing through the perforated element into the first portion of the transport air outlet duct is then deflected and guided along the perforated element and reaches the second portion of the transport air outlet duct at the end of the perforated element.

[0023] It is particularly preferred that the cross section of the first and second portions of the transport air outlet duct is designed such that the transport air reaches a minimum speed of 12 m / s. The speed value of the transport air in the transport air outlet duct is selected in this way such that the resulting dust and fibre residues carried through the perforations by the transport air into the transport air outlet duct. This can prevent dust and fibre residues from accumulating in the transport air outlet duct. A maintenance opening is preferably provided between the first and second portions for the inspection and any necessary cleaning of the transport air outlet duct. BRIEF DESCRIPTION OF DRAWINGS

[0024] The application is described in more detail below on the basis of embodiments and with reference to the drawings. In the drawings:

[0025] Figure 1 is a schematic view of a spinning preparation machine;

[0026] Figure 2 is a schematic view of a cross section at the point X-X according to Figure 1

[0027] Figure 3 is a first embodiment of a perforated element;

[0028] Figure 4 is a second embodiment of a perforated element, and

[0029] Figure 5 is a schematic view of a cross section of a further embodiment of a transport air outlet duct. DETAILED DESCRIPTION

[0030] Figure 1 is a schematic view of a spinning preparation machine 1 according to the application, and Figure 2 is a schematic view of a cross section at the point X-X according to Figure 1 ​Fig. 1 shows a schematic view of a cross-section at the point X-X. A spinning preparation machine 1 of the slide mixer type is shown, which has four slides 2 to 5. The individual slides 2 to 5 are separated from one another by slide partition walls 17 to 19, which separation is provided over the entire width B but not over the entire height H of the slide mixer. The slides 2 to 5 are provided as slides 2 to 5 which are open at the top and the bottom and limited on four sides. Slide 4 is, for example, delimited by slide partition walls 17 and 18 and slide outer walls 19 and 20. At the lower end of each slide partition wall 17 to 19, a slide partition wall end piece 20 is provided which directly adjoins the slide partition wall 17 to 19. The slide partition wall end piece 20 serves to divert the fibre flow sliding downward through the slides 2 to 5 from a vertical movement into a horizontal movement.

[0031] The fibre material is introduced into the spinning preparation machine 1 in the form of a fibre-air mixture 7 with the aid of the transport air 10 through a fibre material inlet 6 and is guided through a distribution duct 11 above the slides 2 to 5 to a transport air outlet duct 9. The distribution duct 11 is delimited on three sides by an upper distribution duct wall 14 and two lateral distribution duct walls 15 and 16. The distribution duct 11 is open opposite the slides 2 to 5. In the Figure 1 In the figure, this delimitation of the distribution duct 11 is shown with the aid of the duct line 12. A perforated element 13 is inserted into the transition from the distribution duct 11 to the transport air outlet duct 9. The perforated element 13 separates the distribution duct 11 from the transport air outlet duct 9. As a result, the transport air 10 is separated from the fibre material. The perforated element 13 has a convex shape with a radius R when viewed in the direction from the fibre material inlet 6 to the transport air outlet 8. In order to improve the flow in the distribution duct 11, an air guiding element 21 is attached above each of the slide partition walls 17 to 19.

[0032] The transport air 10 is discharged from the transport air outlet duct 9 via the transport air outlet 8. The transport air outlet duct 9 is designed in such a way that it wraps around the perforated element 13 in the shape of a hood and is arranged with its wall at a distance A from the perforated element 13. This shape allows the transport air 10 to pass unhindered through the perforated element 13.

[0033] The deflection of the fibre material in the individual slides 2 to 5 and the subsequent horizontal transport to a removal device 25 with the aid of a conveyor belt 24 and the further increase in transport within the removal device 25 allows the fibre material to be mixed. In the embodiment shown, the removal device 25 is formed by a pin curtain and a discharge roller. The mixed fibre material is transferred from the removal device 25 into an outlet duct 26, which leads to a fibre material outlet 27.

[0034] Figure 3A first embodiment of the perforated element 13 is shown, which consists of a plurality of individual screen elements 28. The screen elements 28 are designed as flat screen surfaces provided with perforations 30. The perforations 30 are schematically shown in Figure 3 and extend uniformly over all screen elements 28 of the perforated element 13. The screen elements 28 are arranged one after the other in this way, so that they result in a convex element 13 in the form of an arcuate configuration with a radius R.

[0035] Figure 4 A second embodiment of the perforated element 13 is shown, which also consists of individual screen elements 28 arranged one after the other. The perforated element 13 is divided into two regions 29 and 31, the first region 29 being designed with perforations 30 that are different from the perforations 32 in the second region 31. The perforations 30 in the first region 29 are larger than the perforations 32 in the second region 31. This results in a more uniform flow through the perforated element 13 over its entire length. The perforations 30 and 32 are schematically shown in Figure 4 and extend uniformly over the corresponding screen elements 28 of the regions 29 and 31 of the perforated element 13. Furthermore, the convex perforated element 13 extends over an angle a of more than 90 degrees. The increased arc length of more than 90 degrees results in a better discharge of the transport air through the perforated element 13.

[0036] Figure 5 is a schematic view of a cross section of a further embodiment of the transport air outlet duct 9. The perforated element 13 is shown as a circular arc with a radius R and an angle a of more than 90 degrees. In contrast to the hood-like configuration of the transport air outlet duct 9 as shown in Figure 1 , Figure 5 the transport air outlet duct 9 in consists of a first portion 35 arranged behind the perforated element 12 and a second portion 36 downstream of the first portion 35 and carrying the transport air 10 to the transport air outlet 8. The flow 33 of the transport air 10 through the perforated element 13 being guided into the first portion 35 of the transport air outlet duct 9 and from the first portion 35 into the second portion 36 is shown with arrows. The transport air outlet 8 is shown by way of example as a flange. A maintenance opening 34 is shown between the portions 35 and 36 of the transport air outlet duct 9.

[0037] The invention is not limited to the embodiments shown and described. Modifications can be made within the scope of the claims, even if features are shown and described in different embodiments. Combinations of features are possible.

[0038] List of reference signs

[0039] 1 Spinning preparation machine

[0040] 2-5 Slide

[0041] 6 fibre material inlet

[0042] 7 fibre air mixture

[0043] 8 transport air outlet

[0044] 9 transport air outlet duct

[0045] 10 transport air

[0046] 11 distribution duct

[0047] 12 duct line

[0048] 13 perforated element

[0049] 14 upper distribution duct wall

[0050] 15-16 lateral distribution duct wall

[0051] 17-19 slide separation wall

[0052] 20 slide separation wall end piece

[0053] 21-22 outer slide wall

[0054] 23 air guiding element

[0055] 24 conveyor belt

[0056] 25 removal device

[0057] 26 outlet duct

[0058] 27 fibre material outlet

[0059] 28 screen element

[0060] 29 first region

[0061] 30 perforations of the first region

[0062] 31 second region

[0063] 32 perforations of the second region

[0064] 33 flow

[0065] 34 maintenance opening

[0066] 35 first portion of the transport air outlet duct

[0067] 36 second portion of the transport air outlet duct

[0068] A distance

[0069] B width

[0070] H total height

[0071] R radius

[0072] a angle

Claims

1. A spinning preparation machine (1) for mixed fibres, comprising a removal device (25) for removing fibres from the spinning preparation machine (1) and a filling device for filling the spinning preparation machine (1) with fibres, wherein The spinning preparation machine (1) is designed as a slide mixer with at least two slides (2-5), wherein the filling device has a fiber material inlet (6) and a transport air outlet (8) and a distribution pipe (11), the transport air outlet having a transport air outlet pipe (9), the distribution pipe extending from the fiber material inlet (6) to the transport air outlet (8) above the at least two slides (2-5), characterized in that the distribution pipe (11) is separated from the transport air outlet (8) by a perforated element (13), the perforated element (13) being designed to have a convex shape when viewed along the direction of the transport air outlet (8).

2. Spinning preparation machine (1) according to claim 1, characterized in that The slide (2-5) is surrounded by an airtight slide partition wall (17-20).

3. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that The distribution pipe (11) is surrounded on at least three sides by airtight pipe walls (14, 15, 16).

4. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that The convex shape of the perforated element (13) is formed by a row of flat screen elements (28).

5. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that The convex shape of the perforated element (13) corresponds to an arc with a radius (R) ranging from 200 mm to 1000 mm.

6. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that The perforated element (13) has 20% to 50% perforation.

7. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that The perforated element (13) is divided into at least two regions (29, 31), each region (29, 31) having a different perforation (30, 32).

8. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The convex perforated element (13) extends over an angle (α) of more than 90 degrees.

9. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, A cover element for setting a negative pressure in the transport air outlet duct (9) is provided on the side of the perforated element (13) facing the transport air outlet (8).

10. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The perforations in the perforating element (13) are formed by round or angular openings with a cross section of less than 0.1 cm 2 .

11. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The perforated element (13) is made of metal.

12. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The perforated element (13) is made of plastic material.

13. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, An air guiding element (21) is disposed in the distribution pipe (11) above the slide partition wall (17, 18) between the two slides (4, 5).

14. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The transport air outlet duct (9) has a first portion (35) and a second portion (36) adjacent to the first portion (35), the first portion (35) being guided along the perforated element (13) and the second portion (36) being guided away from the perforated element (13).

15. The spinning preparation machine (1) according to claim 1 or claim 2, characterized in that, The transport air outlet pipe (9) is designed to allow the transport air (10) to reach a minimum speed of 12 m / s.

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