|Title of Invention||
A CARDING DEVICE COMPRISING A DISCARD UNIT FOR THE SEPERATE CAPTURE OF SEPERATED MATERIAL
|Abstract||The invention relates to a carding device comprising a discard unit for the separate capture of separated material, in particular for the removal of waste that is ejected from the take-in unit and/or from the cleaning duct. At least one ejection point is connected to a negative pressure source via the discard unit and an air-permeable wall is located between the negative pressure source and the ejection point in the discard unit, said wall retaining the separated material in the discard unit. Fig. 2a|
UNIT FOR REMOVING WASTE IN A CARDING DEVICE
The invention relates to a unit for removing waste at a carding device, in particular for removing waste that is ejected from the licker-in unit and/or from the cleaning duct.
The tasks of a carding device comprise opening as far as individual fibres, separation of impurities, separation of dust, opening of neps and forming a sliver. The separation of impurities takes place primarily in the area of the licker-in unit. Only a small part of the impurities goes along with the flat waste and is deposited at other locations. The percentage purity of the modern carding machine is very high, being 80-95%. A large amount of dirt is released by the aggressive opening of the flocks at the feeding trough by the licker-in unit. As a result, the waste at the licker-in unit contains a large amount of dirt (70-90%). In contrast to the waste at the drum or at the flat, this tends to contain dust, neps, short fibres and good fibres; the separation at the licker-in unit takes place via adjustable blades. If a high percentage purity is required, these blades are set in such a manner that more material is separated. Since the blades on the licker-in unit can separate selectively, principally "dark waste" (dust, stalk parts, leaf residue, seed coat fragments) are separated. Waste only containing material unusable for the subsequent spinning process is formed. As a result of the separate capture of this material, this can be removed separately and reprocessed. Thus, the "dark waste" is no longer supplied to the spinning process during the reprocessing and is usually pressed into pellets and sold. It is also advantageous for observing the cleaning function of the licker-in unit if the separated material can be assessed separately.
Furthermore, a cleaning location can be provided at the opening roller in the filling box. The separation is also selective at this cleaning location and can contain a high amount of "dark waste" depending on the setting.
The individual separation points of the carding machine, both that of the licker-in unit and that of the drum and flats, are brought together into a manifold in a modern carding machine and conveyed into a central discard container. The suction capacity is limited
partly because of the high cost and partly because of the negative effect which too-strong suction has on the separation efficiency of the individual separation points.
Thus, EP 750 059, for example, discloses a system where the waste of the licker-in falls into a separate container and is only intermittently removed therefrom. By short-term throttling of the suction at the other location and extracting from the container in this period, greater influencing of the remaining locations can be minimised and the waste can, if necessary, be removed or collected by means of a flap via a separate path. However, a prerequisite of this method is that the separation points at the licker-ins are directed downwards and the separation points located above the roller require suction to remove the separated particles before they are pulled back to the roller again.
It is thus the object of the invention to provide a discard unit and a method which avoids said disadvantages, which in particular allows separate removal without exerting an effective influence on the separation points of the carding machine.
This object is achieved according to the invention by a device according to claim 1.
The discard unit consists of a container comprising at least two chambers, separated by an air-permeable wall, e.g. a filter cloth, a perforated sheet or a screen plate. The chamber which effectively collects the waste has at least one inlet connected to a separation point or the separation points so that the waste can be captured separately from the other separation points and an outlet for further transport of the captured material. In addition, an opening for scavenging air can also be provided. The other chamber has only one opening, which is connected to a negative pressure source. This source can, for example, be a central suction channel which is used for the remaining separation points. Apart from the inlet connected to the separation point, all the outlets and inlets are provided with means for opening and closing so that the process can proceed in a controlled manner.
In normal operation, the inlet connected to the separation point and the outlet connected to the negative pressure source will be open so that the separated waste is extracted by
suction and held in the collecting chamber with the aid of the air-permeable wall. The extracted air leaves the housing through the air-permeable wall via the outlet in the second chamber. The inlet and the air-permeable wall are preferably arranged in such a manner that the air stream can brush the air-permeable wall surface and thereby clean the air-permeable wall. This eliminates manual cleaning processes and cleaning devices for the air-permeable wall are also superfluous. The air-permeable wall is preferably arranged with respect to the outlet connected to the negative pressure source in such a manner that optimal use is made of the surface of the air-permeable wall. If in particular the distance between the inlet and the outlet is selected as being as far from one another as possible, the air-permeable wall can be used over the entire surface.
The inlet is preferably arranged in such a manner that gravity can additionally be responsible for depositing the dirt material but without adversely influencing the effect of the air-permeable wall. The inlet and outlet are preferably arranged in such a manner that the material air flow can cover the longest path via the air-permeable wall so that the separation function of this wall can be optimally utilised.
The outlet connected to the negative pressure source is then intermittently closed and the outlet connected to the channel for the removal, which is also connected to a negative pressure source, is opened. An inlet connected to the scavenging air is possibly also opened. Although a compressed air source can be provided for the scavenging air, it is more favourable to arrange only one opening in communication with the surroundings. Since the chamber is at a negative pressure at all times, either connected by the inlet to a negative pressure source or by the removal channel which is also connected to the negative pressure source, air is sucked in from the surroundings through an opening. This sucked-in air stream is sufficient to convey the collected material into the transport channel. The advantage of this method is that the opening connected to the separation point need not be closed. The separation point is thereby continuously exposed to suction. This eliminates influences on the separation point by interruptions in the suction or by fluctuations in the suction perfonnance.
The collected material is removed from the collecting chamber and fed via a dedicated channel either to a collecting point for re-usable waste where all card waste of this type is collected or returned to be re-introduced to the process again at a suitable point. A separate air stream is preferably fed as scavenging air over the base of the collecting chamber to guarantee the removal of heavier particles and so that the process can be shortened in time. The material outlet and possibly the scavenging air opening are closed again and the inlet connected to the separation point and the outlet connected to the negative pressure source are opened again.
The bottom of the collecting container is preferably constructed such that the dirt particles are collected in a groove, the shape of the groove being adapted to the openings for the scavenging air and the removal.
The intermittent extraction of the waste from the discard unit particularly has an advantage in larger systems consisting of a plurality of cards, each having a discard unit. If each discard unit is permanently exposed to separate suction, the overall suction performance is then higher and the separate removal is thus more expensive. With intermittent suction, the suction performance only needs to be sufficient for one or several cards and can be constructed cost-effectively.
If necessary, the discard unit can also be designed in such a manner that a plurality of separation points can be captured separately. For example, waste from the cleaning duct and the licker-in unit can be received separately by a triple-chamber discard unit, the middle chamber being separated from the other two chambers by means of air-permeable walls. The middle chamber is connected to a negative pressure source and the outer chamber is provided either for receiving waste from the licker-in unit or waste from the cleaning duct. It is simplest if the two chambers are emptied at the same time but via separate channels.
Fig. 1 is a schematic diagram of a card
Fig. 2 is a schematic diagram of the discard unit according to the invention from
above, Figure 2a and from the side, Figure 2b.
Figure 1 shows a revolving flat card 1, e.g. the Rieter C60 card having a working width of 1.5 metres, with a cleaning duct 9. Fibre flocks are transported through transport channels (not shown) through the various blow room process stages and ultimately fed into the cleaning duct of the card. The cleaning duct consists of an upper duct part 10 and a lower duct part 13. Located between the two duct parts is an opening roller which is fed by means of a feed device 11. Cleaning elements 12 which provide the separation of dirt particles are arranged on the opening roller. However, strictly selective cleaning is not provided here so that good fibres can also be separated. These are captured in a suction channel and passed on.
The cleaning duct then passes the fibre flocks as lap to the card. The feeding device 7 feeds the fibre flocks to the licker-in units 6. The licker-in units open the fibre flocks and remove some of the dirt particles. The last licker-in roller transfers the fibres to the card cylinder 2. The card cylinder 2 cooperates with the flats 4 and hereby parallelises the fibres still further. The flats are cleaned by a flat cleaner 5. After the fibres have in some cases executed several circuits on the card cylinder, they are removed from the card cylinder by the doffer 3, fed to the squeeze roller 8 and finally laid in a can coiler in a can as card sliver (not shown). The separation points are normally connected to the machine extraction (25, Figure 2).
All the separation points marked with a star in the drawing can be connected to the separate waste removal according to the invention. Figures 2a and 2b show a schematic example of how a discard unit 16 can be accommodated in the card 1 with duct 9. Figure 2a shows a side view and Figure 2b shows a view from above. Waste removal and card or cleaning shaft are not shown in relation to one another.
In this example, the discard unit 16 is fitted with two chambers 22, 23 which are separated by an oblique air-permeable wall 21. This air-permeable wall can, for example, be a filter tensioned on a frame.
Three factors are crucial for the optimum effect of the discard unit: the air-permeable wail has the largest possible surface area, the air can make optimum use of this surface and the dirt particles do not impede any of the suction processes.
The air-permeable wall is therefore arranged substantially vertically so that no waste can settle on the wall. Since the air-permeable wall is not attached completely straight in the container but at a slight angle, the possibility of particles settling can be further reduced and the filtering surface remains optimised.
Since the outlet connected to the negative pressure source is arranged as far as possible from the inlet connected to the separation point, the sucked-in air stream does not select a shortened path via the air-permeable wall but uses the entire surface. Since the negative pressure source can at the same time be the suction channel for the other separation point of the card, this possibly lies on the wrong side for forming an optimal inlet. Figure 2 therefore shows an alternative for lengthening the outlet connected to the negative pressure source by means of a channel whereby the same effect can be achieved as when the outlet were arranged opposite to the wall.
The inlet 17 is, for example, connected to a separation point 24 in the card. These mostly run as a channel over the working width of the card as can be seen from Figure 2b. The inlet is arranged in such a manner that gravity can also be responsible for separating the dirt particles and that the settled particles do not swirl up again. The second chamber 22 is connected to the central suction via outlet 20 to generate the negative pressure.
The channel connections can be formed with separation points so that the device can be simply removed. For this purpose, the device can additionally run on wheels or on rails so that removal is simplified.
A facility for manual sampling can preferably also be provided at the collecting chambers of the discard unit so that the waste composition can be assessed.
1. A carding device comprising a discard unit for the separate capture of separated material, wherein at least one separation point is connected to a negative pressure source via the discard unit, characterised in that the separation point is allocated to the licker-in unit and/or the cleaning duct and an air-permeable wall is arranged between the negative pressure source and the separation point in the discard unit.
2. The carding device comprising a discard unit according to claim 1, wherein the air-permeable wall is arranged vertically.
3. The carding device comprising a discard unit according to claim 1 or 2, wherein the air-permeable wall is arranged so that it is obliquely inclined in such a manner that no dirt particles can rest on the wall.
4. The carding device comprising a discard unit according to any one of the preceding claims, wherein the partial region in which the ejected material is retained is connected to the removal channel wherein the opening to this channel is fitted with means for closing.
5. The carding device comprising a discard unit according to any one of the preceding claims, wherein the partial region in which the ejected material is retained in connected to a closable inlet for scavenging air.
6. The carding device comprising a discard unit according to any one of the preceding claims, wherein means for closing the connection are allocated to the connection to the negative pressure source.
7. The carding device comprising a discard unit according to any one of the preceding claims, wherein a regulator and/or a control system is allocated to the means for closing the individual openings.
8. The carding device comprising a discard unit according to any one of the
preceding claims, wherein located between the air-permeable wall and the
negative pressure source in the discard unit is a partial space which ensures that
the air stream from the separation point escapes over the entire surface of the
9. The carding device comprising a discard unit according to any one of the
preceding claims, wherein the air-permeable wall is a frame with a filter cloth.
10. The carding device comprising a discard unit according to any one of the
preceding claims, wherein the discard unit is configured with a plurality of air-
permeable walls and outlets connected to removal channels in such a manner
that the waste from a plurality of separation points can be captured separately
and transported further.
|Indian Patent Application Number||3088/CHENP/2007|
|PG Journal Number||36/2013|
|Date of Filing||12-Jul-2007|
|Name of Patentee||MASCHINENFABRIK RIETER AG|
|Applicant Address||KLOSTERSTRASSE 20 CH-8406 WINTERTHUR|
|PCT International Classification Number||D01G15/76|
|PCT International Application Number||PCT/CH05/00733|
|PCT International Filing date||2005-12-08|