CN114351297A

CN114351297A - Spinning preparation machine

Info

Publication number: CN114351297A
Application number: CN202111188152.5A
Authority: CN
Inventors: A·希尔特; T·沃尔菲尔
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2020-10-13
Filing date: 2021-10-12
Publication date: 2022-04-15
Also published as: CH717947A1; EP3985151A1

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 fibrous material inlet (6) and a transport air outlet (8) with a transport air outlet duct (9) and a distribution duct (11) leading from the fibrous material inlet (6) to the transport air outlet (8) via the at least two ramps (2-5). The distribution duct (11) is separated from the transport air outlet (8) by a perforating element (12), which perforating element (12) is designed to have a convex shape when viewed in the direction of the transport air outlet (8).

Description

Spinning preparation machine

Technical Field

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 chute mixer with at least two mixing chambers, the filling device has a fibrous material inlet and a transport air outlet with a transport air outlet duct, and a distribution duct leading from the fibrous material inlet to the transport air outlet via the at least two mixing chambers.

Background

In the fiber preparation system of a spinning mill, the supplied fibers or fiber clusters are prepared for use in a spinning machine. In a fiber preparation system, the fiber to be prepared for spinning is subjected to a number of processing stages. In the first stage, the fibers are removed from the fiber bag (bag) in the form of fiber clusters. So-called bale breakers are commonly used for this purpose. These fibre mats are transported out of the bale breaker by means of pneumatic mat transport and are transferred, for example, to a downstream cleaning machine.

Downstream of the cleaning machine, the fibre flocks are generally conveyed into a mixer which ensures, for example, that the fibre flocks are mixed by various chutes. The fibers are then removed from the mixer via a removal device, for example by means of a spiked curtain, and transported further. DE 37135902 a1 discloses a mixer with a plurality of filling chutes. These filling skids are filled simultaneously via a pneumatic transport system. By controlling the removal device of each chute, thorough mixing of the fibrous material is achieved.

EP 0874070 a1 also discloses a chute mixer with a plurality of chutes. The fibrous material is distributed to the various chutes or chambers of the mixer by pneumatic conveyance with the aid of transport air. The transport air is discharged from the chamber into the exhaust duct via the air-permeable side walls.

The chute mixer is divided into various chutes, which are open at the upper side and connected to pneumatic conveying lines. The incoming fibre flocks are distributed evenly to the various chutes via distributors. Downstream of the dispenser, the chute extends first in the vertical direction, after which it is bent through 90 °, so that the chute or its tuft filling now extends in the horizontal direction. Their horizontal extension ends with a curtain of staples that sweeps across all slides and removes fibers in a substantially vertical direction from bottom to top. This design of the mixer as a chute mixer ensures that: due to the different lengths of the runners (i.e. the distance the fibres have to cover), the fibres can be mixed, since the fibres fed to the mixer at different times and thus from different bales can be removed from the various runners simultaneously by the removal means. This type of construction of the chute mixer has proven itself.

A disadvantage of this design is that it is complicated to separate the fibrous material from the transport air. Each chamber or each chute is provided with an air-permeable wall, which also results in multiple risks of clogging. During operation, the permeability of the individual partition walls changes, which can lead to different filling of the slide due to pressure conditions, which must be corrected by corresponding control of the dispensing.

Disclosure of Invention

It is therefore an object of the invention to create a device which provides a simple separation of the fibre material and the transport air and avoids different influences on different filling levels of the mixer chute by separating the transport air from the fibres in a chute-wise manner (cut-wise).

This problem is solved by a device having the features of the independent claim. In order to solve this problem, a novel spinning preparation machine for mixing fibers 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 fibers. The spinning preparation machine is designed as a chute mixer with at least two chutes, the filling device has a fibrous material inlet and a transport air outlet with a transport air outlet duct, and a distribution duct leading from the fibrous material inlet to the transport air outlet via the at least two chutes. The distribution pipe is separated from the transport air outlet by a perforated element. The perforating element is designed to have a convex shape when viewed in the direction of the transport air outlet.

The transport duct is provided as a filling device, through which the fibre material is brought together with transport air as a fibre-air mixture into the distribution duct. The dispensing conduit remains open to the chute. Due to the flow directed through the fibrous material inlet, the transport air follows the distribution pipe to the transport air outlet. The transport air outlet is arranged on the opposite side to the fibrous material inlet so that the fibrous air mixture is swept over the chute. The fibres or fibre flocks fall down into the chute. At the end of the distribution pipe, a perforated element is mounted as a curved element to separate the fibrous material from the transport air and thus the distribution pipe from the transport air outlet pipe. When the fibre material is left open, the transport air passes through the perforations into the transport air outlet duct. The convex shape of the perforating element causes the fibre air mixture to accelerate in the upper region of the distribution duct upstream of the perforating element, which facilitates automatic cleaning of the perforating element. It has also been shown that the flow generated in the distribution duct due to the arrangement and shape of the perforating elements and the resulting pressure conditions in the individual runners are conducive to an even distribution of the fibres entering the runners. The positioning of the transport air outlet duct or the fibrous material inlet with respect to the longitudinal axis of the machine is of no consequence. The transport air outlet duct and the fibrous 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 ideally be integrated into an existing fiber preparation system of a spinning mill.

The fibers extend through the various chutes and are mixed by deflection and with the aid of a take-off device. The principle of a vertical and then horizontal flow through the chute before the fibre reaches the take-off device is known from the prior art. As a removal device, for example, a pin curtain can be used as an ascending conveyor which removes the fibers from the various chutes on the one hand and conveys the removed fibers into the fibrous material outlet on the other hand.

The chute is advantageously surrounded by a gas-impermeable chute wall. 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 is not uncontrolled via the individual chute walls, the chute can be filled uniformly under constant flow and pressure conditions.

It is also advantageous that the distribution conduit is surrounded on at least three sides by a gas-impermeable conduit wall. Efforts in earlier designs to separate a portion of the transport air to one side of the distribution pipe based on 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 load in the transport air with fibre material is subject to constant fluctuations. The risk of clogging of the air-permeable element is also minimized, in particular also due to foreseeable flow and pressure conditions and central separation of the transport air and the fibres. Due to the prevailing flow conditions and pressure conditions in the slide, the slide is filled evenly even without corresponding guiding elements (such as baffles or metal sheets) in the distribution pipe.

The convex shape of the perforating elements is preferably formed by flat screen elements arranged in a row. As an alternative to a perforated element designed in the shape of a circular arc, this is produced by arranging flat screen elements in rows. The individual screen elements are joined together in such a way that an overall convex shape of the perforated element results. The individual screen elements have corresponding perforations and are connected to each other, for example by welding, gluing or screwing. In an alternative production method, the perforated element can be formed from flat sheet metal by a corresponding folding process or by forming curved edges between the screen elements. The curved edges will be seen as a restriction to the individual screen elements. In this way the production of the perforating element can be simplified and more cost-effective than by rolling sheet metal to a large diameter. The narrower the individual screen elements are designed, the closer the shape of the assembled or connected screen elements is to a circular arc segment. If the perforated element consists of more than three screen elements, the segment-by-segment configuration of the male perforated element has no decisive influence on the function of the perforated element or on the flow conditions.

The convex shape preferably corresponds to a circular arc 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 perforating elements results in advantageous flow conditions that prevent fibers from getting stuck in the perforations. In order to achieve good breathability and avoid excessive dynamic pressure, the perforated element preferably has a perforation (or "perforation") of 20% to 50%. This means that at least 20% but not more than 50% of the surface is perforated, i.e. per cm in the perforated element²Area provides 0.2 cm²And 0.5 cm²Free passage in between. Too high a perforation will allow good fibresThe fiber passes through or snaps into the hole and creates an attachment point.

The perforating element is advantageously divided into at least two areas, which have different perforations. For example, the upper half of the perforating element is designed with 28% perforations and the lower half of the perforating element is designed with 21% perforations. 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 more uniformly split over the cross section of the perforated element. This design of the perforated element is advantageous in case a construction is used in which screen elements are arranged in a row. More than two regions with different perforations are also conceivable. Each screen element can easily be provided with different perforations.

Advantageously, the male perforating elements extend over an angular range of more than 90 degrees. This increases the screen area and improves flow conditions. The flow conditions upstream of the perforating element are also influenced in such a way that no or only a small amount of transport air is discharged from the distribution pipe into the last ramp in front of the perforating element through the convex shape of the perforating element.

In a further development of the invention, a cover element for setting the underpressure in the transport air outlet duct is provided on the side of the perforating 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 perforating element influences the pressure and flow conditions on the perforating element and enables a desired pressure difference to be set across the perforating element. As a result, the air is made uniform through the perforated element. At the same time, the escaping transport air is kept free of a large amount of dust or fibre parts when using the filter cloth.

The perforations in the perforating element are advantageously made of a cross-section of less than 0.1 cm²Is formed with rounded or angular openings. The small cross-sectional dimensions of the individual openings in the perforation prevent or at least severely restrict the passage of reusable fibres through the perforation element into the transport air outlet duct.

The perforating element is preferably made of metal. Alternatively, the perforating element is made of a plastic material. When the perforating 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 (due to the flow through the perforating element). However, in the case of smaller dimensions of the chute mixer, it is also possible to use a perforated element made of plastic material with sufficiently high stability and strength.

The air guide element is preferably arranged in the distribution duct above the chute partition wall between the two chutes. The air guiding element is designed as an upper closure of the chute partition wall. The air guide element accelerates the flow from the fibrous material inlet to the transport air outlet briefly, which results in an improved distribution of the fibrous material on the chute. The shape of the air guiding element against the distribution duct is advantageously provided with a convex closure in order to avoid adhesion of fibres.

Advantageously, the transport air outlet duct has a larger cross section than the perforating element. The transport air outlet duct is arranged at a distance around the perforating element in the shape of a hood. 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 perforating element becomes more uniform. Furthermore, a service opening is preferably provided in the transport air outlet duct in order to check the condition of the perforating element and to be able to clean the transport air outlet duct if necessary. At least a part of the service opening is advantageously designed to be transparent.

In an alternative to the hood-like design of the transport air outlet duct, the transport air outlet duct advantageously has a first portion and a second portion adjoining the first portion, the first portion being guided along the perforating element and the second portion being guided away from the perforating element. The design of the first part of the transport air outlet duct is adapted to the convex perforating element, so that an arched duct is created. 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 at the end of the perforated element to the second portion of the transport air outlet duct.

Particularly preferably, the cross-section of the first and second section of the transport air outlet duct is designed such that a minimum velocity of 12 m/s of the transport air is reached. The speed value of the transport air in the transport air outlet duct is selected in such a way that the resulting dust and fibre residues which enter the transport air outlet duct through the perforations are carried all the way by the transport air. This can prevent dust and fibre residues from accumulating in the transport air outlet duct. A service opening is preferably provided between the first and second portions for inspection and any necessary cleaning of the transport air outlet duct.

Drawings

The invention is explained in more detail below on the basis of embodiments and with reference to the drawings. In the drawings:

FIG. 1 is a schematic view of a spinning preparation machine;

FIG. 2 is a schematic view of a cross section at point X-X according to FIG. 1;

FIG. 3 is a first embodiment of a perforating element;

FIG. 4 is a second embodiment of a perforating element, an

FIG. 5 is a schematic illustration of a cross-section of yet another embodiment of a transport air outlet duct.

Detailed Description

Fig. 1 is a schematic view of a spinning preparation machine 1 according to the invention and fig. 2 is a schematic view of a section at point X-X according to fig. 1. A spinning preparation machine 1 of the slide mixer type is shown, which has four slides 2 to 5. The individual ramps 2 to 5 are separated from one another by ramp partition walls 17 to 19, which separation is provided over the entire width B of the ramp mixer, but not over the entire height H. The runners 2 to 5 are provided as runners 2 to 5 which are open at the top and bottom and limited on four sides. For example, the chute 4 is bounded by

chute divider walls

17 and 18 and chute

outer walls

19 and 20. At the lower end of each chute partition wall 17 to 19, a chute partition wall end piece 20 is provided which directly adjoins the chute partition wall 17 to 19. The chute divider wall end piece 20 serves to divert the flow of fibers sliding down through the chutes 2-5 from vertical movement to horizontal movement.

The fibre material is introduced into the spinning preparation machine 1 through the fibre material inlet 6 in the form of a fibre air mixture 7 with the aid of transport air 10 and is guided to the transport air outlet duct 9 through a distribution duct 11 above the slideways 2 to 5. 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 pipe 11 is open opposite the skids 2 to 5. In fig. 1, such a delimitation of the distribution pipe 11 is shown with the pipe course 12 as an auxiliary line. The perforating element 13 is inserted in the transition from the distribution duct 11 to the transport air outlet duct 9. The perforated element 13 separates the distribution pipe 9 from the transport air outlet pipe 9. As a result, the transport air 10 is separated from the fibre material. The perforating element 13 has a convex shape with a radius R, when viewed in the direction from the fibrous material inlet 6 to the transport air outlet 8. To improve the flow in the distribution duct 11, an air guiding element 21 is attached above each of the chute partition walls 17 to 19.

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

The deflection of the fibre material in the respective chutes 2 to 5 and the subsequent horizontal transport to the removal device 25 with the aid of the conveyor belt 24 and the increased transport again in the removal device 25 allow the fibre material to be mixed. In the embodiment shown, the removal device 25 is formed by a curtain of staples and a discharge roller. The mixed fibre material is transferred from the removal device 25 into an outlet conduit 26 leading to a fibre material outlet 27.

Fig. 3 shows a first embodiment of the perforating element 13, which consists of a plurality of individual screen elements 28. The screen element 28 is designed as a flat screen surface provided with perforations 30. The perforations 30 are schematically shown in fig. 3 and extend evenly over all screen elements 28 of the perforated element 13. The screen elements 28 are arranged one after the other in such a way that they produce a male element 13 in an arcuate configuration with a radius R.

Fig. 4 shows a second embodiment of the perforating element 13, which also consists of individual screen elements 28 arranged one after the other. The perforating element 13 is divided into two

areas

29 and 31, the first area 29 being designed with perforations 30 which are different from the perforations 32 in the second area 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 perforate element 13 over its entire length. The

perforations

30 and 32 are schematically shown in fig. 4 and extend uniformly over the corresponding screen elements 28 of the

areas

29 and 31 of the perforated element 13. Furthermore, the male perforating element 13 extends over an angle α of more than 90 degrees. An increased arc length of more than 90 degrees results in a better discharge of transport air through the perforated element 13.

Fig. 5 is a schematic view of a cross-section of a further embodiment of the transport air outlet duct 9. The perforating element 13 is shown as a circular arc having a radius R and an angle alpha exceeding 90 degrees. In contrast to the hood-like configuration of the transport air outlet duct 9 as shown in fig. 1, the transport air outlet duct 9 in fig. 5 consists of a first portion 35, which is arranged behind the perforating element 12, and a second portion 36, which is downstream of the first portion 35 and carries the transport air 10 to the transport air outlet 8. The flow 33 of the transport air 10 through the perforated element 13 into the first section 35 of the transport air outlet duct 9 and from the first section 35 into the second section 36 is shown by arrows. The transport air outlet 8 is shown by way of example as a flange. The service opening 34 is shown between the

parts

35 and 36 of the transport air outlet duct 9.

The invention is not limited to the embodiments shown and described. Within the scope of the claims, modifications are possible and combinations of features are possible even if these features are shown and described in different embodiments.

List of reference numerals

1 spinning preparation machine

2-5 slideway

6 fibrous Material Inlet

7 fiber air mixture

8 transport air outlet

9 transport air outlet duct

10 transporting air

11 distribution pipe

12 pipeline route

13 perforating element

14 upper distribution pipe wall

15-16 lateral distribution duct walls

17-19 chute partition wall

20 slideway partition wall end piece

21-22 outer chute wall

23 air guide element

24 conveyer belt

25 removing device

26 outlet duct

27 fibrous material outlet

28 Screen element

29 first region

30 perforation of the first zone

31 second region

32 perforation of the second area

33 flow

34 service opening

35 first part of the transport air outlet duct

36 second part of the transport air outlet duct

Distance A

Width B

Total height of H

Radius R

The angle alpha.

Claims

1. 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 with at least two chutes (2-5), wherein the filling device has a fiber material inlet (6) and a transport air outlet (8) with a transport air outlet duct (9) leading from the fiber material inlet (6) to the transport air outlet (8) via the at least two chutes (2-5) and a distribution duct (11), characterized in that the distribution duct (11) is separated from the transport air outlet (8) by a perforation element (12), the perforating element (12) is designed to have a convex shape when viewed in the direction of the transport air outlet (8).

2. Spinning preparation machine (1) according to claim 1, characterized in that the slideways (2-5) are surrounded by air-impermeable slideway walls (17-20).

3. Spinning preparation machine (1) according to claim 1 or claim 2, characterized in that the distribution conduit (11) is surrounded on at least three sides by a gas-impermeable conduit wall (14, 15, 16).

4. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the convex shape of the perforating element (13) is formed by a row of flat screen elements (28).

5. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the convex shape of the perforating element (13) corresponds to a circular arc with a radius (R) in the range from 200 mm to 1000 mm.

6. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforating element (12) has a perforation of 20% to 50%.

7. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforating element (13) is divided into at least two regions (29, 31), the regions (29, 31) having different perforations (30, 32).

8. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the male perforating element (13) extends over an angle (a) of more than 90 degrees.

9. 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 duct (9) is arranged on the side of the perforating element (13) facing the transport air outlet (8).

10. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforations in the perforating element (13) consist of a cross section of less than 0.1 cm²Is formed with rounded or angular openings.

11. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforating element (13) is made of metal.

12. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the perforating element (13) is made of plastic material.

13. The spinning preparation machine (1) according to at least one of the preceding claims, characterised in that an air guiding element (21) is arranged in the distribution duct (11) above a chute partition wall (17, 18) between the two chutes (4, 5).

14. 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) being guided along the perforating element (13) and the second section (36) being guided away from the perforating element (13).

15. Spinning preparation machine (1) according to at least one of the preceding claims, characterized in that the transport air outlet duct (9) is designed such that the transport air (10) reaches a minimum velocity of 12 m/s.