CN110318124B

CN110318124B - Feeding device for carding machine

Info

Publication number: CN110318124B
Application number: CN201910243495.3A
Authority: CN
Inventors: C.米勒; R.比肖夫; P.耶利内克
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2018-03-29
Filing date: 2019-03-28
Publication date: 2023-02-24
Anticipated expiration: 2039-03-28
Also published as: CH714843A1; EP3546625A1; CN110318124A; EP3546625B1

Abstract

The invention relates to a method and a device for feeding fibrous material (4) to a carding machine (1). The device comprises a hopper (2), a hopper discharge (5), a feed channel (3) and a fan (18) for compacting the fibrous material (4) in the feed channel (3) to a specific fibrous packing weight. The hopper discharge device (5) has a feed roller (23), which feed roller (23) is driven by a frequency converter (23) having a feed chute (25) for metering the fibrous material (4) emerging from the hopper (2) and a split roller (7) for conveying the fibrous material (4) from the feed roller (6) to the feed channel (3). A control system (31) is provided, wherein a target volume flow (V) of the fan (18) and a set point pressure (P) in the feed channel (3) are associated with respective specific fibre filler weights for different fibre filler weights. A pressure measuring device (24) is arranged in the feed channel (3).

Description

Feeding device for carding machine

Technical Field

The invention relates to a device for feeding fibrous material to a carding machine, having a hopper, a hopper discharge, a feed channel and a fan for compacting the fibrous material in the feed channel into a fibrous wadding having a specific weight of the fibrous wadding, and to a method for controlling the weight of the fibrous wadding.

Background

The carding machine produces card slivers from fibrous material, which are subsequently further processed into yarns. However, nonwoven fabrics can also be made instead of carding slivers. In these cases, the carding machine is usually associated with a hopper supplied by a conveyor system with the fibres coming from the blowing plant. The fibers are transported in the form of a flock. The hopper is filled with the flock continuously or by on-demand control from the conveying system. In most cases, a pneumatic conveying system is used. From the hopper, the fibre flocks are introduced into the carding machine by means of a feed device in the form of a wad of fibres. The uniformity of the fibre wadding entering the carding machine plays an important role in the service life of the working elements of the carding machine and in the requirements placed on the carding quality. The uniformity of the card web or nonwoven produced by the card is also affected by the uniformity of the fibrous wadding entering the card. Another important technical factor in the carding process is the weight of the fibre wadding entering the card. The amount of the wadding by weight and the entry speed of the wadding into the card substantially determine the throughput of the card and are secondary factors for achieving a certain carding quality. The weight of the fibre wadding that can be processed by the carding machine can also be determined by the product to be processed.

A feed roll for continuously pulling lint from a hopper cooperating with the feed chute is arranged in the lower part of the hopper or, in an alternative type of design, in the lower part of the upper chute. The flock, pulled from the hopper by the feed roll, is fed via the opening roll to the feed channel for additional opening and homogenization. In the feed channel, the flock is shaped by means of compressed air to form a uniform wadding feed suitable for feeding to a carding machine. A fan is also provided which is associated with the feed device and which is capable of effecting a pressure increase in the feed channel and thus compacting the flock into a fibrous wad. Due to the pressure generated in the feed channel by the fan, the flock is compacted into a fibrous wad. Air flowing through the fan and entering the feed channel is drawn from the feed channel at its end via the air-permeable wall and returned to the fan.

From the prior art according to CH 693 419 A5, a feed of a carding machine is known, wherein the fibre flocks are discharged from a supply hopper via a feed roller and a shedding roller to a feed channel (feed chute) of the carding machine. In the hopper, air flowing through is applied to the fibrous material. At the lower end of the hopper, an air outlet opening is provided through which air leaves the hopper. The cross-section of the hopper is designed to be adjustable at the air outlet opening. One disadvantage of such a design is that it is not possible to adjust the density or filling level of the fibrous material in the hopper uniformly and automatically.

Another type of design of the feed hopper is disclosed in CH 706 658 A1, for example. This publication shows a two-part hopper comprising an upper chute and a lower chute. The upper chute is filled with lint, which is then transported from the upper chute to the lower chute by the feeding device. The flock is conveyed from the chute to the carding machine in the form of a wad of fibres which is fed downstream from the chute through a feed channel without means for influencing the wad of fibres being provided inside the feed channel. The feed channel only transports the fibre wadding from the lower chute to the card. One disadvantage of such a design is that it is not possible to uniformly and automatically adjust the density or filling level of the fibrous mass in the feed channel before feeding the fibrous wadding to the carding machine.

Disclosure of Invention

It is therefore an object of the present invention to provide a feed device which automatically adjusts the compaction and filling level of the wadding in the feed channel, thereby enabling the card to be supplied with a uniform wadding of fibre.

Another object of the invention is to adjust the filling level in the feed channel over the working width of the card in order to achieve a constant and uniform feed of the fibre wadding to the card.

This object is achieved by a feed device having the features of the present application.

Proposed is a device for feeding fibrous material to a carding machine, having a hopper, a hopper discharge, a feed channel and a fan for compacting the fibrous material in the feed channel to a defined fibrous wad weight. The hopper discharge has a feed roller driven by a frequency converter, the feed roller having a feed chute for metering the fibrous material emerging from the hopper and a split roller for conveying the fibrous material from the feed roller to the feed channel. A control system is provided in which a target volumetric flow rate of the fan and a set point pressure in the feed channel are associated with respective specific fiber packing weights of different fiber packing weights. A pressure measuring device is provided in the feed channel. The control of the characteristics of the wadding at the downstream end of the feed channel is decisive, since the uniformity of the wadding entering the card is important. The air introduced into the feed channel by the fan is discharged from the fan via a gas-permeable portion of the feed channel at the downstream end of the feed channel. If the feed channel is now filled with fibrous material, the air introduced by the fan must pass through the fibrous material to reach the air-permeable portion at the downstream end of the feed channel. Whereby the fibre material is compressed by the air. The greater the compaction of the fibrous material, the more resistance to the airflow from the fan is experienced. The amount of compaction determines the weight of the fibrous filler of the fibrous material that is compacted into the fibrous filler. Thus, the weight of the fibrous filler is determined by the resistance of the fibrous material against the incoming air. The compaction of the fibrous material, which is decisive for achieving the weight of the fibrous filler, depends on the pressure applied to the fibrous mass of the air introduced by the fan. Due to this dependency, the pressure of the air flow introduced into the feed channel by the fan is specified.

By varying the filling level in the feed channel, air is forced to flow through the larger mass of fibrous material in order to reach the gas-permeable wall of the feed channel. The filling level in the feed channel therefore has a significant influence on the air volume flow. The filling level in the feed channel is set accordingly by adjusting the air volume flow.

Various types of fibers and blends thereof are processed in a carding machine. They differ in specific properties such as material (cotton, synthetic fibers, viscose, etc.) or fiber length (e.g. short or medium ply) or proportion of different fibers in the fiber blend. The weight of the fibrous wadding of the feed for the carding machine is established to be suitable based on the fibrous material to be processed, the throughput to be achieved and the requirements placed on the carding quality. The spinning specialist sets the fiber filler weight of the fiber material to be supplied on the basis of their relevant experience. The set point value of the pressure in the feed channel and the volume flow of the fan are stored in the control system for various fibre mat weights. A pressure measuring device arranged in the feed channel makes it possible to maintain a predetermined set point pressure by controlling the speed of the feed rollers and thus the amount of fibrous material reaching the feed channel. On the other hand, the filling level in the feed channel is defined by influencing the volume flow.

In case of a change in the throughput, for example an increase in the production of the carding machine, more fibre wadding is discharged from the infeed channel into the carding machine, resulting in a reduced level in the infeed channel. This is usually compensated by directly controlling the feed rate of the feed rolls. Despite direct control, if a decrease in the fill level occurs, the amount of air resistance to the fan is reduced and, therefore, the pressure in the feed channel decreases below the set point pressure. The control system responds to this by increasing the speed of the feed rollers to restore the set point pressure.

Advantageously, fibrous filler weight control is provided in the control system. To control the weight of the fibrous filler, the control system determines an actual value of the weight of the fibrous filler. Determining the actual fibrous filler weight is known from the prior art; such a process is described, for example, in EP 2 867 392 A1. If there is a difference between the predetermined target fibre fill weights, on the basis of which on the one hand the setpoint values for the fan volume flow and the pressure are assigned and on the other hand the actual fibre fill weight is assigned, the setpoint value for the pressure is corrected while maintaining the setpoint value for the fan volume flow. This is because a correction of the weight of the fibrous filler requires a change in the pressure in the feed channel. However, a filling level of the feed channel determined by the volume flow may remain.

The actual value of the fiber filling weight is determined by means of the calculation of the weight of the produced card sliver or nonwoven, the total draft of the card and the output of the deposition. The individual fibers of the fibrous material are parallelized in the carding machine and leave the carding machine in the form of a nonwoven fabric or a card sliver. In this process, the wadding is pulled apart so that the produced card sliver leaves the card at an exit speed that is greater than the entry speed of the wadding into the card. This process is called drawing. This drafting takes place on a plurality of rollers arranged in the carding machine. The individual drafts occurring from roll to roll can amount to the total draft of a so-called carding machine. The total draft of the card is known from the operating state of the card and is determined by the machine control itself. The total draft of the card corresponds to the ratio of the exit speed of the card sliver or nonwoven to the entry speed of the wadding of fibers. By controlling the drives at the inlet and outlet of the carding machine and the control variables from the outputs to the respective motors, the machine control determines the speed of the motors and hence the peripheral speed of the rollers driven by the motors. Other means for determining the entry or exit speed include measuring means such as the rotational speed of the rollers or shafts. Contaminants and short fibers are removed from the fibrous material in the carding machine by cleaning and parallelization of the fibrous material. The system components removed from the fibrous material are referred to as waste. The amount of waste can be determined by means of a waste function based on the throughput. The machine type and the waste function of the fibrous material to be processed are usually determined once by empirically measuring the waste amount under different production conditions and with different fibrous materials. For example, the measurement of the weight of the sliver at the outlet of the carding machine is carried out by measuring the disk roller nip or a radiation measuring system for measuring the nonwoven.

Preferably, the fan has a drive with an inverter for controlling the motor speed. In this way, the fan can be set directly to the new set point value by the control system. As an alternative to a drive with frequency control, a control gear or control means may be provided in the air inlet or air outlet duct of the fan. In order to achieve a uniform distribution of the fibrous material over the entire width of the feed channel, a new speed set point value must be established. The uneven distribution of the fibrous material results in an irregular fibrous wadding in the feed channel when seen over the working width of the card. In this case, the weight of the wadding of fibres will not be the same over the entire width of the card, due to the presence of holes or edge tears of the wadding of fibres at the outer end of the feed channel. This may also lead to a reduction of the possible throughput or, in case of an up-regulation of the weight of the fibrous wadding, to an excessive weight of the fibrous wadding in the central area of the feed channel. The air volume flow in the feed channel has an influence on the filling level. In some cases, excessive volume flow may result in uneven compaction of the fibrous filler due to the formation of vent channels in the fibrous filler from the feed channel to the air permeable region of the feed channel wall.

It is also advantageous if a sensor for measuring the opening of the feed chute is provided. The density or compaction of the flock removed from the hopper by the feed rollers also has an effect on the fibrous packing formed in the feed channel. At high densities, the air permeability of the fibrous material is reduced and a lower filling level in the feed channel is reached at the same pressure set point value. However, compensating for this by adjusting the pressure in the feed channel is not satisfactory in all cases, since stagnant adjustments lead to excessive reaction times, which may cause clogging of the feed channel in case of a temporary rise in the filling level. In the case of high density lint in the hopper, removal of the lint with the feed roll causes the feed chute to open. The feed chute is elastically supported and opened or closed by the lint as needed. By detecting the position of the feed slot sensor and properly considering the speed of the feed rollers, variations in lint density can be quickly identified. This makes it possible to reduce the feed when dense lint occurs, thereby preventing clogging of the feed passage. The configuration of the sensor may be a distance measuring sensor or a displacement measurement (e.g. of inductive or capacitive type) or a rotation angle sensor, corresponding to the design of the feed chute and/or its movement.

Conversely, if the density of the lint is reduced, the feeding can be increased by increasing the speed of the feeding roller, thereby preventing the feeding passage from idling due to insufficient supply. Taking into account the density of the flock by measuring the opening of the feed chute allows the feed channel to have a short construction.

Furthermore, a device is proposed which is capable of adjusting the filling level in the feed channel independently of the fibre wadding density. The device for feeding fibrous material to a carding machine comprises a feed channel and a fan for compacting the fibrous material in the feed channel to a defined fibrous wadding weight. The fan has a drive with a frequency converter for speed control or a control device for controlling the volume flow. A filling sensor is provided in the feed channel to measure the filling level. The fill sensor may be implemented as a single sensor or as a plurality of sensors. The uniformity of the fill level must be ensured over the entire working width of the card. Examples of conceivable sensor configurations include optical or production volume sensors. For reasons related to construction, the specified filling level (set point value) is the same for all types of applications of a particular feed channel design due to geometry.

It is advantageous to provide a volumetric flow control that calculates a correction of the fan speed or position of the control device from a comparison of the measured fill level with a target fill level. Due to the built-in feed channel, the target filling level can be present as a fixed value in the control system. Alternatively, the fixed value can also be determined by the installation position of the filling sensor, so that a measured value of the filling level results in a difference of the direct measured value from the target filling level.

Furthermore, a carding machine with a device for feeding fibrous material is proposed, wherein the device is embodied according to the above description.

Furthermore, a method for supplying a carding machine with a certain quantity of fibrous material is proposed, in which the fibrous material is fed from a hopper with a feed roller into a feed channel, which feed roller cooperates with a feed chute via a split roller downstream of the feed roller and is fan compacted in the feed channel into a fibrous wadding having a wadding weight. The target volume flow of the fan and the set point pressure in the feed channel are related to the weight of the selected fibrous pack to be supplied. In the feed channel, the actual pressure is measured using a pressure sensor, and the drive of the feed roll is controlled by means of a frequency converter on the basis of a comparison of the set-point pressure in the feed channel with the actual pressure, while maintaining the desired volume flow.

Advantageously, the distribution of the set point pressure is influenced by the fibrous wadding weight control means on the basis of the selected fibrous wadding weight while maintaining the target volume flow. Since the venting channel is formed by the fibrous filler from the feed channel to the air-permeable region of the feed channel wall, an excessive volume flow of air in the feed channel can lead to uneven compaction of the fibrous filler. Preferably, the change in set point pressure due to the weight control of the fibrous wadding with a constant target volume flow is compensated by a corresponding adjustment of the speed of the feed roll. The speed is regulated by means of a frequency converter associated with the drive or control gear. Furthermore, it is advantageous to achieve a compensation of the target volume flow by correspondingly adjusting the speed of the fan or the position of the control device in order to maintain the filling level.

Furthermore, it is advantageous to measure the opening of the feed chute with a sensor. Thus, the measured opening of the feed chute may preferably be used as a correction factor for controlling the feed rollers. This serves the purpose of preventing clogging or short supply in the feed channel due to variations in the density of the flock in the hopper.

Drawings

Further advantages of the invention are described in the following exemplary embodiments. In the drawings:

fig. 1 is a schematic side view of a carding machine according to the prior art;

fig. 2 shows a schematic view of a device according to the invention in a first embodiment;

fig. 3 shows a schematic view of a device according to the invention in another embodiment; and

fig. 4 shows a schematic view of a device with fill level control according to the invention.

Detailed Description

Fig. 1 shows a carding machine 1, which is equipped with a hopper 2, a hopper discharge 5 and a feed channel 3. After having passed the various processing steps of the blowing plant, the fibre material 4 arrives in the hopper 2. The fibrous material 4 passes through a hopper discharge device 5 to a feed channel 3, which comprises a feed roller 6 and an opening roller 7 and an air supply device 8. An air supply device 8 is provided in the hopper discharge device 5 in order to support the transfer of the chips from the opening roller 7 to the feed channel 3 and to ensure the compaction of the fibre wadding 11 in front of the feed device 10 of the carding machine 1. The air supply device blows air 8 tangentially along the opening roller 7 into the feed channel 3 and thereby compresses the fibre flocks into a wad of fibres 11, which has a high wad weight, which is necessary for further processing in the carding machine 1. The air 8 blown in by the air supply device flows through the lint discharged from the opening roller 7 into the feed channel 3. The gas stream leaves the feed channel 3 through a gas-permeable area 9 of the wall at the end of the feed channel 3.

A feed device 10 after the feed channel 3 feeds the flock (now in the form of a homogeneous wadding feed 11) into a lickerin module 12 of the carding machine 1. A card feed roll with a feed chute for metering the fibrous wadding 11 is provided for the feed device 10. The flock discharged from the fibrous wad feed 11 by the feed device 10 is further opened by the lickerin comprised in the lickerin module 12 and at the same time a part of the impurities contained therein is removed. The last taker-in of the taker-in module 12 finally delivers the fibres to the carding cylinder 13, the carding cylinder 13 breaking completely and parallelizing the fibres. For this purpose, the carding cylinder 13 cooperates with a lid assembly 14. After the fibers have partly undergone several rotations on the carding drum 13, they are removed from the carding drum 13 by the doffer roller 15, fed to the sliver forming unit 16 and finally deposited in cans (not shown) in the form of a card sliver 17.

Fig. 2 shows a schematic view of a device according to the invention in a first embodiment. The fibrous material 4 is removed from the hopper 2 by a feed roll 6. For this purpose, the feed rollers 6 cooperate with the feed chute 25. The feed chute 25 is provided with a spring mechanism 26, which spring mechanism 26 presses the feed chute 25 against the feed roll 6. The feed chute 25 is opened by the fibre material 4 more or less against the spring mechanism 26, and the fibre material 4 is taken out of the hopper 2 by the feed roller 6 according to the density of the fibre material 4. The feed roll 6 conveys the fibrous material 4 to the opening roll 7. The opening roller 7 transfers the fibrous material 4 from the feed roller 6 into the feed channel 3, where the fibrous material 4 is further transported to the carding machine.

Below the opening roller 7, air 8 is introduced into the feed channel 3 by a fan 18 with a drive through an air supply duct 19. The flock in the feed channel 3 is conveyed by air towards the card and is compacted into a wad of fibres 11 at the end of the feed channel 3. The air 8 introduced into the feed channel 3 by the fan 18 is again discharged from the feed channel 3 through the air-permeable region 9 in the wall of the feed channel 3 at the end of the feed channel 3 and returns to the fan 18 via the return line 28. A leakage air opening 29 is provided in the return line 28. The leakage air openings 29 serve the purpose of compensating for the loss of air position along the entire air supply from and to the fan 18, which may leak. The fibre wadding 11 is formed by air 8 from the fibre flocks at the end of the feed channel 3 and is compacted by the air pressure. The pressure is created because the air 8 has to overcome the resistance to flow through the fibre packing 11 in order to pass through the air-permeable area 9 from the feed channel 3 to the return line 28. A fibrous wadding 11 having a certain filling level 34 is formed in the feed channel 3.

A pressure sensor 24 for measuring the actual pressure of the air 8 in the feed channel 3 is arranged in the feed channel 3. The pressure in the feed channel 3 is decisive for the density of the fibrous wadding 11 and thus represents the specification of the weight W of the fibrous wadding achieved at the end of the feed channel 3.

A control system 31 is also shown. The characteristic curves of the target volume flow V and the setpoint pressure P of the air 8 are stored in the control system 31. The desired weight W of the fibrous filler is input into the control system 31 via input 33. The corresponding target volumetric flow V and setpoint pressure P are assigned to the fibre wadding weight W by the control system 31. The actual pressure in the feed channel 3 is measured by means of a pressure sensor 24. By comparing the set point pressure with the actual pressure, a suitable correction of the speed of the feed roll 6 is calculated in the control system and the speed of the feed roll 6 is corrected via a frequency converter 23 acting on the drive 22 of the feed roll 6. A constant pressure and a constant volume flow in the feed channel 3 are thus ensured.

Fig. 3 shows a schematic view of a device according to the invention in another embodiment. The present arrangement of the device, which is the same as the arrangement of fig. 2, comprises a hopper 2, a feed roller 6, a feed chute 25 with a spring load 26, a split roller 7 and a feed channel 3, as well as a fan 18 with an air supply duct 19 and a return line 28. The description of the leakage air opening 29, the air-permeable area 9 and the filling level 34 can also be gathered from fig. 2.

A pressure sensor 24 for measuring the actual pressure of the air 8 in the feed channel 3 is arranged in the feed channel 3. The pressure in the feed channel 3 is decisive for the density of the fibre wadding 11 and thus represents the specification of the weight W of the fibre wadding achieved at the end of the feed channel 3.

A control system 31 is also shown. A characteristic curve of the target volume flow V and the setpoint pressure P of the air 8 is stored in the control system 31. The desired weight W of fibrous filler is input into the control system 31 via input 33. A corresponding target volumetric flow V and setpoint pressure P are assigned to the fiber fill weight W by the control system 31. The actual pressure in the feed channel 3 is measured by means of a pressure sensor 24. By comparing the set point pressure with the actual pressure, a suitable correction of the speed of the feed roll 6 is calculated in the control system and the speed of the feed roll 6 is corrected via a frequency converter 23 acting on the drive 22 of the feed roll 6. Thus ensuring a constant pressure and a constant volume flow in the feed channel 3.

Furthermore, in the embodiment shown in fig. 3, the control system 31 is connected to a fibrous wad weight control device 30. The target wadding weight of input 33, corresponding to the wadding weight, is compared to the actual wadding weight on the card. In case of a corresponding deviation, the setpoint pressure P in the feed channel 3 is increased by the control system 31. The speed of the drive 22 of the feed roll 6 is varied by the control system 31 via the frequency converter 23. In order to maintain the target volume flow V despite the change in the setpoint pressure P, the speed of the drive 20 of the fan 18 can be regulated by the control system 31 via the frequency converter 21, or alternatively, instead of the speed of the fan 18 in the return line 28, a control device 32 can also be provided which can also change the volume flow. Since the air-permeable region 9 of the wall of the feed channel 3 forms an air-venting channel from the feed channel 3 to the fibrous filler 11, an excessive volume flow of air 8 in the feed channel 3 can lead to uneven compaction of the fibrous filler 11.

In the embodiment shown, an opening sensor 27 is additionally provided on the feed chute 25. The opening sensor 27 measures the opening state of the feed chute 25 and thereby provides information about the density of the fibrous material 4 currently removed from the hopper 2 by the feed rollers 6. This information is processed by the control system 31 and applied as a correction factor to control the speed of the drive 22 of the feed roll 6.

Fig. 4 shows a schematic view of a device according to the invention with control of the filling level 34. The present arrangement of the device with respect to the hopper 2 with fibrous material 4, the feed roller 6, the feed chute 25, the split roller 7 and the feed channel 3 partly filled with fibrous wadding 11, and the fan 18 with the air supply duct 19 and the return line 28 is the same as the arrangement according to fig. 2. The description of the leakage air openings 29, the gas permeable area 9 and the filling level 34 can also be gathered from fig. 2. The fan 18 delivers air 8 with a specific volume flow to the fibre wadding 11 through the air supply duct 19 and the feed channel 3. As a result, a filling level 34 is formed at the end of the feed channel 3, which represents the area of the feed channel 3 filled with fibrous filler 11. The fill sensor 35 is arranged near the target fill level. The current filling level 34 or the difference between the current filling level 34 and the target filling level is forwarded to the volumetric flow control device 36. By means of corresponding control signals, the volume flow control device 36 controls the speed of the fan 18 and/or its drive 20 by means of the frequency converter 21. As an alternative to controlling the speed of the fan 18 by its drive, the position of the control device 32 present in the supply or discharge line of the fan 18 can be suitably varied by means of the volume flow control device 36.

The invention is not limited to the exemplary embodiments which have been shown and described. Modifications are possible within the scope of the claims in accordance with combinations of features, even if such combinations are shown and described in different exemplary embodiments.

List of reference numerals

1. Carding machine

2. Hopper

3. Feed channel

4. Fibrous material

5. Hopper discharging device

6. Feed roller

7. Opening roller

8. Air (a)

9. Breathable zone of wall

10. Feeding device

11. Fibrous filler

12. Licker-in module

13. Carding drum

14. Cap assembly

15. Doffer roller

16. Yarn strip forming unit

17. Sliver of carding machine

18. Fan (Ref. TM. Fan)

19. Air supply duct

20. Driver (Fan)

21. Frequency converter (Fan)

22. Driver (feed roller)

23. Frequency converter (feed roll)

24. Pressure sensor

25. Feed chute

26. Spring mechanism

27. Opening sensor

28. Return line

29. Leakage air opening

30. Weight control device for fiber filler

31. Control system

32. Control device

33. Input weight of fibrous filler

34. Fill level

35. Fill sensor

36. Volume flow control device

Weight of fibrous filler of W

Vtarget volume flow

P set point pressure.

Claims

1. A device for feeding fibrous material (4) to a carding machine (1), having a hopper (2), a hopper discharge (5), a feed channel (3) and a fan (18) for compacting the fibrous material (4) in the feed channel (3) to a specific fibrous wadding weight, wherein the hopper discharge device (5) has a feed roller (6) driven by a frequency converter (23) and has a feed chute (25) for metering the fibrous material (4) from the hopper (2) and a split roller (7) for conveying the fibrous material (4) from the feed roller (6) to the feed channel (3), characterized in that a control system (31) is provided in which a target volume flow (V) of the fan (18) and a setpoint pressure (P) in the feed channel (3) for different fibre wadding weights (W) are assigned to the respective specific fibre wadding weight (W), and, a pressure sensor (24) for measuring the actual pressure is provided in the feed channel (3), wherein the drive (22) of the feed roll (6) is controlled by means of a frequency converter (23) on the basis of a comparison of the set-point pressure and the actual pressure in the feed channel (3) while maintaining the target volume flow.

2. An arrangement according to claim 1, characterized in that a fiberfill weight control arrangement (30) is provided in the control system.

3. Device according to claim 1 or 2, characterized in that the fan (18) has a drive (20) with a frequency converter (21) for speed control.

4. Device according to claim 1 or 2, characterized in that a control device (32) is provided in the air inlet or air outlet duct of the fan (18).

5. Device according to claim 1 or 2, characterized in that a sensor (27) is provided for measuring the opening of the feed chute (25).

6. Device according to claim 1, characterized in that the fan (18) has a drive (20) with a frequency converter (21) for speed control or a control device (32) for controlling the volume flow, and in that a filling sensor (35) for measuring the filling level (34) is arranged in the feed channel (3).

7. A device according to claim 6, characterised in that a volumetric flow control device (36) is advantageously provided which calculates a correction for the speed of the fan (18) or the position of the control device (32) from a comparison of the measured filling level (34) with a target filling level.

8. A carding machine (1) having at least one device according to any of claims 1 to 7.

9. A method of feeding a specific amount of fibrous material (4) to a carding machine (1), wherein the fibrous material (4) is conveyed from a hopper (2) via an opening roller (7) downstream of the feeding roller (6) by means of a feeding roller (6) cooperating with a feeding chute (25) to a feeding channel (3) and is compacted in the feeding channel (3) by means of a fan (18) into a fibrous wad (11) having a fibrous wad weight (W), characterized in that a target volume flow (V) of the fan (18) and a set point pressure (P) in the feeding channel (3) are related to the selected fibrous wad weight (W) to be fed, and in the feeding channel (3) an actual pressure is measured by means of a pressure sensor (24), and the drive (22) of the feeding roller (6) is controlled by means of a frequency converter (23) based on a comparison of the set point pressure and the actual pressure in the feeding channel (3), while maintaining the target volume flow.

10. A method according to claim 9, characterized in that the distribution of the set point pressure (P) is influenced by a fibrous wadding weight control device (30) on the basis of the selected fibrous wadding weight (W).

11. A method according to claim 10, characterized in that the change of the set point pressure (P) due to the fiberfill weight control device (30) is compensated by adjusting the speed of the feed roll (6) accordingly.

12. Method according to any one of claims 9 to 11, characterized in that, in order to maintain the filling level (34), compensation of the target volume flow (V) is effected by correspondingly adjusting the speed of the fan (18) or the position of a control device (32).

13. Method according to any of claims 9 to 11, characterized in that the opening of the feed chute (25) is measured with a sensor (27).

14. A method according to claim 13, characterized in that the measured opening of the feed chute (25) is used as a correction factor for controlling the feed roll (6).