EP3985151A1 - Spinning frame - Google Patents

Abstract

The invention relates to a spinning preparation machine (1) for mixing fibers, with a removal device (25) for removing the air from the spinning preparation machine (1) and with a filling device for filling the spinning preparation machine (1) with fibers, the spinning preparation machine (1) as a Shaft mixer is formed with at least two shafts (2-5). The filling device has a fiber material inlet (6) and a transport air outlet (8) with a transport air outlet channel (9) and a distribution channel (11) leading from the fiber material inlet (6) to the transport air outlet (8) via the at least two shafts (2-5). The distribution channel (11) is separated from the transport air outlet (8) by a perforated element (12), the perforated element (12) being designed with a convex shape viewed in the direction of the transport air outlet (8).

Description

The invention relates to a spinning preparation machine for mixing fibers, with a removal device for removing the fibers from the spinning preparation machine and with a filling device for filling the spinning preparation machine with fibers. The spinning preparation machine is designed as a shaft mixer with at least two mixing chambers, with the filling device having a fiber material inlet and a transport air outlet with a transport air outlet channel and a distribution channel leading from the fiber material inlet to the transport air outlet via the at least two mixing chambers

In a fiber preparation plant in a spinning mill, delivered fibers or fiber tufts are prepared for use in a spinning machine. In a fiber preparation plant, the fibers to be prepared for spinning go through several processing stages. In a first stage, the fibers are separated from fiber bales in the form of fiber flocks. So-called bale openers are usually used for this. These fiber tufts are removed from the bale opener by a pneumatic tuft conveyor and taken to a downstream cleaning machine, for example.

Downstream of the cleaning machine, the fiber tufts are usually conveyed into a mixer which, for example, ensures that the fiber tufts are thoroughly mixed via various shafts. The fibers are then removed from the mixer via a removal device, for example by means of a needle lattice cloth, and transported further. the DE 37 13 5902 A1 discloses a mixer with multiple hoppers. The filling shafts are filled at the same time via the pneumatic transport system. A thorough mixing of the fiber material is achieved by controlling the removal devices of the individual shafts.

Next revealed the EP 0 874 070 A1 a shaft mixer with several shafts. The fiber material is distributed to the various shafts or chambers of the mixer with a pneumatic conveying system using transport air. The transport air is discharged from the chambers into an exhaust air duct via air-permeable side walls.

The shaft mixer is divided into different shafts, which are open at the top and are connected to the pneumatic conveying line. The incoming fiber tufts are evenly distributed to the various shafts via a distributor. After the distributor, the ducts initially extend in the vertical direction before they make a 90° bend, so that the ducts or their flake fillings now extend in the horizontal direction. Its horizontal extent ends in front of a riser slatted cloth, which sweeps past all shafts, essentially in a vertical direction from bottom to top, and removes the fibers. This design of the mixer as a shaft mixer ensures that, due to the different lengths of the shafts, i.e. path lengths that the fibers have to cover, the fibers are mixed by the fibers being fed to the mixer at different times and thus from other bales at the same time be removed from the various shafts by the removal device. This design of shaft mixers has proven itself.

The disadvantage of this design is that separating the fiber material from the transport air is expensive. Each chamber or shaft is provided with an air-permeable wall, which also results in a multiple risk of blockages. During operation, the air permeability of the individual partition walls changes, which means that the shafts can be filled differently due to the pressure conditions, which must be corrected by appropriate distribution control.

The object of the invention is therefore to create a device which provides for a simple separation of fiber material and transport air and thereby avoids a different influencing of the different fill levels of the shafts of the mixer by shaft-by-shaft separation of the transport air from the fibers.

The object is solved by a device having the features of the independent claim. A novel spinning preparation machine is used to solve the task proposed for mixing fibers with a removal device for removing the air from the spinning preparation machine and with a filling device for filling the spinning preparation machine with fibers. The spinning preparation machine is designed as a shaft mixer with at least two shafts, the filling device having a fiber material inlet and a transport air outlet with a transport air outlet channel and a distribution channel running from the fiber material inlet to the transport air outlet via the at least two shafts. The distribution channel is separated from the transport air outlet by a perforated element. The perforated member is formed in a convex shape as viewed in the direction of transport air outlet.

A transport channel is provided as a filling device, through which the fiber material is brought into the distribution channel with transport air as a fiber-air mixture. The distribution channel is kept open to the shafts. Due to the flow guided through the fiber material inlet, the transport air follows the distribution channel to the transport air outlet. The transport air outlet is arranged on a side opposite the fiber material inlet, so that the fiber-air mixture sweeps over the ducts. The fibers or the fiber tufts fall down into the shafts. At the end of the distribution channel, the perforated element is installed as a curved element to separate the fiber material from the transport air and thus separates the distribution channel from the transport air outlet channel. The transport air passes through the perforation into the transport air outlet channel while the fiber material is held up. Due to the convex shape of the perforated element, the fiber-air mixture is accelerated in the upper area of the distribution channel in front of the perforated element, which contributes to the automatic cleaning of the perforated element. It has also been shown that the currents arising in the distribution channel due to the arrangement and shape of the perforated element, as well as the resulting pressure conditions in the individual ducts, promote an even distribution of the fibers entering the ducts. The positioning of the transport air outlet channel or the fiber material inlet in relation to the longitudinal machine axis is irrelevant. The transport air outlet channel as well as the fiber material inlet can be provided both at the front of the machine and at the rear of the machine. Through this the machine can be ideally integrated into an existing fiber preparation system in a spinning mill.

The fibers pass through the individual shafts and are mixed by a deflection and with the help of the extraction device. The principle of the first vertical and then horizontal flow through the shafts before they reach the removal device is known from the prior art. As a removal device, for example, a needle lattice cloth can be used as an ascending conveyor, which on the one hand removes the fibers from the various shafts and on the other hand conveys the removed fibers to a fiber material outlet.

The shafts are advantageously surrounded by shaft walls which are impermeable to air. Since the separation of the transport air from the fibers is concentrated on the transition from the distribution channel to the transport air outlet channel and does not take place in an uncontrolled manner via individual shaft walls, the shafts can be filled evenly under constant flow and pressure conditions.

It is also advantageous if the distribution channel is surrounded on at least three sides by airtight channel walls. Attempts in earlier constructions to separate part of the transport air to the side of the distribution channel according to the distance covered have proven to be disruptive. This is also due to the fact that the fibre-air mixture is not homogeneous and the loading of the transport air with fibrous material is subject to constant fluctuations. The risk of clogging of the air-permeable elements is also minimized, in particular due to the foreseeable flow and pressure conditions in the case of a central separation of transport air and fibers. Due to the prevailing flow conditions and the pressure conditions in the shafts, the shafts are filled evenly even without appropriate guide elements such as flaps or plates in the distribution channel.

Preferably, the convex shape of the perforated element is formed from a row of flat screen elements. As an alternative to a perforated element designed in the shape of an arc of a circle, this is produced by lining up flat sieve elements. The individual screen elements are joined together in such a way that that an overall convex shape of the perforated element arises. The individual screen elements have a corresponding perforation 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 metal sheet by a corresponding folding process or by forming bent edges between the screen elements. The bending edges are to be considered as a limitation of the individual screen elements. The production of the perforated element can be simplified in this way compared to production by rolling a metal sheet into a large diameter and is less expensive. The narrower the design of the individual screen elements, the more the shape of the assembled or connected screen elements approaches a segment of a circular arc. A segmented construction of the convex perforated element has no decisive influence on the functioning of the perforated element or the flow conditions if the perforated element is made up of more than three screen elements.

The convex shape preferably corresponds to an arc of a circle with a radius in a range from 200 mm to 1000 mm, particularly preferably in a range from 400 mm to 800 mm. The size of the radius to be selected depends on the size of the spinning preparation machine. Such a configuration of the perforated element leads to advantageous flow conditions, which prevent fibers from getting stuck in the perforation. In order to achieve good air permeability and to avoid excessive dynamic pressure, the perforated element preferably has a perforation of 20% to 50%. This means that at least 20%, but no more than 50% of the surface is perforated, ie there is between 0.2 cm ² and 0.5 cm ² free passage per cm ² of area in the perforated element. Too high a perforation would allow good fiber to pass through the holes or get caught in the holes and create snag points.

The perforated element is advantageously divided into at least two areas, the areas having different perforations. For example, an upper half of the perforated element with a perforation of 28% and a lower Half of the perforated element executed with a perforation of 21%. Because of the resulting flow conditions, the differential pressure across the perforated element can be equalized in this way, and the transport air is separated off more evenly across the cross section of the perforated element. Such a design of the perforated element is favored in a construction by lined-up screen elements. More than two areas with different perforations are also conceivable. The individual screen elements can easily be provided with different perforations.

It is advantageous if the convex perforated element extends over an angle of more than 90 degrees. This increases the screen area and also improves the flow conditions. The flow conditions in front of the perforated element are also influenced in such a way that no or only a small amount of transport air is diverted from the distribution channel through the convex shape of the perforated element into the last shaft in front of the perforated element.

In a further development of the invention, a cover element for setting a negative pressure in the transport air outlet channel is provided on a 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 pressure and flow conditions at the perforated element are influenced by a targeted partial covering of the perforation of the perforated element and a desired differential pressure can be set across the perforated element. As a result, the passage of air through the perforated element is evened out. At the same time, the exiting transport air is kept free of large amounts of dust or fiber particles when using a filter cloth.

The perforation in the perforated element is advantageously formed by round or angular openings with a cross section of less than 0.1 cm ² . The small cross-sectional size of the individual openings prevents or at least prevents perforation severely restricted that good fibers pass through the perforated element into the transport air outlet channel.

Preferably the perforated element is made of metal. Alternatively, the perforated element is made of plastic. If 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 by the flow guided away over the perforated element due to the low edge height of the passages. If the dimensions of the shaft mixer are smaller, however, a perforated element made of plastic with sufficiently high stability and strength can also be used.

An air guide element is preferably provided in the distribution channel above a shaft partition wall between two shafts. The air guide element is designed as the upper end of the shaft partition. The flow from the fiber material inlet to the transport air outlet is briefly accelerated by the air guiding element, which leads to an improvement in the distribution of the fiber material to the shafts. The air guide element is advantageously provided with a convex end in its shape towards the distribution channel in order to prevent fibers from sticking.

It is advantageous if the transport air outlet channel has a larger cross section than the perforated element. The transport air outlet channel is arranged in a hood-like manner around the perforated element with a certain distance. The distance between a wall of the transport air outlet duct and the perforated element is preferably greater than 100 mm. As a result, the flow is calmed and the air passage of the transport air through the perforated element is made more uniform. Furthermore, a maintenance opening is preferably provided in the transport air outlet duct in order to be able to check the condition of the perforated element and, if necessary, to be able to clean the transport air outlet duct. At least part of the maintenance opening is advantageously transparent.

In an alternative to the hood-shaped design of the transport air outlet duct, the transport air outlet duct advantageously has a first section and a second section adjoining the first section, the first section being guided along the perforated element and the second section being guided away from the perforated element. The design of the first section of the transport air outlet channel is adapted to the convex, perforated element, resulting in an arc-shaped channel. The transport air flowing through the perforated element into the first section of the transport air outlet duct is subsequently deflected and guided along the perforated element and reaches the second section of the transport air outlet duct at the end of the perforated element.

Particularly preferably, the cross section of the first section and the second section of the transport air outlet duct is designed in such a way that the transport air reaches a minimum speed of 12 m/s. The value for the speed of the transport air in the transport air outlet duct is selected such that the dust produced and the fiber residues that have reached the transport air outlet duct through the perforation are entrained by the transport air. In this way, accumulation of dust and fiber residues in the transport air outlet duct can be avoided. A maintenance opening is preferably provided between the first section and the second section for inspection and necessary cleaning of the transport air outlet duct.

Figur 1

eine schematische Darstellung einer Spinnereivorbereitungsmaschine;

Figur 2

eine schematische Darstellung eines Schnittes an der Stelle X-X nach Figur 1;

Figur 3

eine erste Ausführung eines perforierten Elements;

Figur 4

eine zweite Ausführung eines perforierten Elements und

Figur 5

eine schematische Darstellung eines Querschnitts einer weiteren Ausführung des Transportluftaustrittskanals.

The invention is explained below using an exemplary embodiment and illustrated in more detail by drawings. Show it

figure 1

a schematic representation of a spinning preparation machine;

figure 2

a schematic representation of a section at point XX figure 1 ;

figure 3

a first embodiment of a perforated element;

figure 4

a second embodiment of a perforated element and

figure 5

a schematic representation of a cross section of a further embodiment of the transport air outlet channel.

figure 1 shows a schematic representation of a spinning preparation machine 1 according to the invention and figure 2 a schematic representation of a section at point XX figure 1 . A spinning preparation machine 1 is shown in the form of a shaft mixer with four shafts 2 to 5. The individual shafts 2 to 5 are separated from one another by shaft partitions 17 to 19, with the separation over the entire width B, but not over the entire height H of the shaft mixer is provided. Shafts 2 to 5 are intended as shafts 2 to 5 which are open at the top and bottom and are limited to four sides. For example, the shaft 4 is delimited by the shaft partitions 17 and 18 and the shaft outer walls 19 and 20. At the lower end of each shaft partition 17 to 19 there is a shaft partition end piece 20 which directly adjoins the shaft partition 17 to 19. The chute partition end piece 20 serves to divert the fiber flow which slides down the chute 2 to 5 from a vertical to a horizontal movement.

The fiber material is introduced into the spinning preparation machine 1 with the aid of transport air 10 through the fiber material inlet 6 in the form of a fiber-air mixture 7 and is guided through a distribution channel 11 via the shafts 2 to 5 to the transport air outlet channel 9 . The distribution channel 11 is delimited on three sides by an upper distribution channel wall 14 and two lateral distribution channel walls 15 and 16 . Opposite the shafts 2 to 5, the distribution channel 11 is open. In figure 1 this demarcation of the distribution channel 11 is displayed with the channel profile 12 as an auxiliary line. A perforated element 13 is inserted in the transition from the distribution channel 11 to the transport air outlet channel 9 . The perforated element 13 separates the distribution channel 9 from the transport air outlet channel 9. As a result, the transport air 10 is separated from the fiber material. The perforated element 13 has a convex shape with a radius R seen in the direction from the fiber material inlet 6 to the transport air outlet 8 . To improve the flow in the distribution channel 11, air guide elements 21 are attached above the shaft partitions 17 to 19.

The transport air 10 is discharged from the transport air outlet duct 9 via the transport air outlet 8 . The transport air outlet channel 9 is designed such that it covers the perforated element 13 in the form of a hood and is arranged with its walls at a distance A from the perforated element 13 . This shape allows the transport air 10 to pass unhindered through the perforated element 13.

The deflection of the fiber material in the individual shafts 2 to 5 and the subsequent horizontal transport with the aid of the conveyor belt 24 to the removal device 25 and the in turn increasing transport within the removal device 25 mixes the fiber material. The removal device 25 in the embodiment shown is formed by a lifting slatted cloth and a discharge roller. The mixed fiber material is transferred from the removal device 25 into an outlet channel 26 which leads to the fiber material outlet 27 .

figure 3 shows a first embodiment of a perforated element 13 which is composed of a plurality of individual sieve elements 28 . The screen elements 28 are designed as flat screen surfaces provided with a perforation 30 . The perforation 30 is in figure 3 shown schematically and extends evenly over all sieve elements 28 of the perforated element 13. The sieve elements 28 are arranged one behind the other in such a way that a convex element 13 in an arcuate configuration with a radius R results.

figure 4 shows a second embodiment of a perforated element 13 which is also composed of individual sieve elements 28 arranged one behind the other. The perforated element 13 is divided into two areas 29 and 31 , a first area 29 having a perforation 30 which differs from the perforation 32 in the second area 31 . The perforation 30 in the first area 29 is larger than the perforation 32 in the second area 31. This results in a more even flow through the perforated element 13 over its entire length. Perforations 30 and 32 are in figure 4 shown schematically and extend evenly over the corresponding sieve elements 28 of the areas 29 and 31 of the perforated element 13. Furthermore, the convex perforated element 13 extends over an angle α of more than 90 angular degrees. Due to the increased arc length of more than 90 degrees of angle, the transport air is better discharged through the perforated element 13.

figure 5 shows a schematic representation 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 α of more than 90 angular degrees. In contrast to the hood-shaped design of the transport air outlet duct 9 as shown in figure 1 is shown, the transport air outlet duct 9 consists in figure 5 a first section 35 which is arranged behind the perforated element 12 and a second section 36 which follows the first section 35 and which brings the transport air 10 to the transport air outlet 8 . The flow 33 of the transport air 10 guided through the perforated element 13 into a first section 35 of the transport air outlet duct 9 and from the first section 35 into the second section 36 is represented by arrows. The transport air outlet 8 is shown as a flange, for example. A maintenance opening 34 is shown between the sections 35 and 36 of the transport air outlet duct 9 .

The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are just as possible as a combination of the features, even if they are shown and described in different exemplary embodiments.

Legend

1

spinning preparation machine

2 - 5

shaft

6

entry of fiber material

7

fiber air mixture

8th

transport air outlet

9

transport air outlet duct

10

transport air

11

distribution channel

12

channel course

13

Perforated element

14

Upper distribution channel wall

15 - 16

Lateral distribution channel wall

17 - 19

shaft partition

20

Manhole partition end piece

21 - 22

shaft outer wall

23

air deflector

24

conveyor belt

25

extraction device

26

exit channel

27

fibrous material exit

28

screen element

29

First area

30

Perforation first area

31

second area

32

Perforation second area

33

flow

34

maintenance opening

35

First section transport air outlet duct

36

Second section transport air outlet duct

A

Distance

B

Broad

H

overall height

R

radius

a

angle

Claims (15)

Spinning preparation machine (1) for mixing fibers, with a removal device (25) for removing the air from the spinning preparation machine (1) and with a filling device for filling the spinning preparation machine (1) with fibers, the spinning preparation machine (1) as a shaft mixer with at least two shafts (2-5), the filling device having a fiber material inlet (6) and a transport air outlet (8) with a transport air outlet channel (9) and a fiber material inlet (6) to the transport air outlet (8) via the at least two shafts (2-5 ) guided distribution channel (11), characterized in that the distribution channel (11) is separated from the transport air outlet (8) by a perforated element (12), the perforated element (12) having a convex, viewed in the direction of the transport air outlet (8). shape is formed. Spinning preparation machine (1) according to Claim 1, characterized in that the shafts (2-5) are surrounded by shaft walls (17-20) which are impermeable to air. Spinning preparation machine (1) according to claim 1 or 2, characterized in that the distribution channel (11) is surrounded on at least three sides by airtight channel walls (14, 15, 16). Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the convex shape of the perforated element (13) is formed from a row of flat sieve elements (28). Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the convex shape of the perforated element (13) corresponds to an arc of a circle with a radius (R) in a range from 200 mm to 1000 mm. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforated element (12) has a perforation of 20% to 50%. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforated element (13) is divided into at least two areas (29, 31), the areas (29, 31) having different perforations (30, 32). Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the convex perforated element (13) extends over an angle (a) of more than 90 angular degrees. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that a cover element for setting a negative pressure in the transport air outlet channel (9) is provided on a side of the perforated element (13) facing the transport air outlet (8). Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforation in the perforated element (13) is formed by round or angular openings with a cross section of less than 0.1 cm ² . Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforated element (13) is made of metal. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforated element (13) is made of plastic. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that in the distribution channel (11) each above a Shaft partition (17, 18) between two shafts (4, 5) an air guide element (21) is provided. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the transport air outlet duct (9) has a first section (35) and a second section (36) adjoining the first section (35), the first section (35) belonging to the along the perforated element (13) and the second section (36) is guided away from the perforated element (13). Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the transport air outlet channel (9) is designed in such a way that the transport air (10) reaches a minimum speed of 12 m/s.

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