AN APPARATUS FOR SEPARATING FIBRE FLIES. DUST AND SHORT FIBRES FROM AIR STREAM AND A METHOD THEREOF

FIELD OF THE INVENTION

The present invention relates to an apparatus used for the removal of fibre flies, dust and short fibres from the re-circulating air in the fibre conveying passage of a textile machine.
More particularly, this invention relates to continual removal of fibre flies, dust and short fibres from the re-circulating air in the fibre conveying passage of a fibre feeding chute that is used for feeding the fibre material to the textile carding machine.

BACKGROUND OF THE INVENTION

The carding machines are provided with a fibre feeding arrangement comprising feed chute for supplying the fibre material to the feed roller area of the carding machine. The fibre feeder is arranged in such a way that the fibre material supplied from the feeding area is uniformly distributed across the entire width of the carding machine and constantly fed to it.
For the purpose of feeding the fibre material, air is used for the transport of the fibre material from the fibre feeder to the card. The fibre material alone is fed to the carding machine and the air from the air-fibre mixture is extracted. The extracted air may be discharged outside the carding room. However in present day cards, it is customary to extract the air with the help of a fan and to re-circulate the same from the top of the feed chute for compressing the fibre tufts present in the feed chute. For the above purpose, the walls of the feed chute are provided with air discharge openings which are arranged to a pre-determined height and disposed across the entire width of the feed chute at its lower portion. With the help of a fan arrangement and suitable ducting, the extracted air is re-directed into the feed chute, which compresses the fibre material. This facilitates the uniform filling of the fibre material across the width of the feed chute. While the fibre material is fed to the card, the air present in the fibre-air mixture is extracted through the air discharge openings.

The extracted air also carries fibre flies, dust and short fibres along with it during its passage through the fibre material and the same is discharged into the feed chute. This is disadvantageous since the fibre flies, dust and short fibres re-circulated along with the air are likely to affect the quality of the card web produced by the carding machine.
Patent specification US4219289 suggests an apparatus comprising a filtering device located in the outflow channel which is provided in order to prevent the dust exiting from the air exit openings to enter the feed chute while returning to the fibre flock fill. The apparatus disclosed in US4219289 is not so effective as the filter area could be blocked/clogged with fibre flies, dust and short fibres over a period of machine working and requires frequent manual cleaning of the filter.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an apparatus which prevents the fibre flies, dust and short fibres extracted from the air-fibre mixture entering into the feed chute along with the re-circulating air.

It is another object of the present invention to provide an apparatus which provides a filtering medium which is substantially free from the accumulation of fibre flies, dust and short fibres.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided an apparatus for separating fibre flies, dust and short fibres from the air stream re-circulating from air discharge openings in a feed chute of a fibre feeder characterized in that, said apparatus has at least a moving filter means for filtering said air stream.

In accordance with another aspect of the invention a method is provided for separating fibre flies, dust and short fibres from the air stream re-circulating from air discharge openings in a feed chute of a fibre feeder comprising the steps of : providing fibre material to a conveying duct; transporting fibre material and air along a vertical chute; transferring fibre material from feed roller to a opening roller and finally to a feed chute; extracting air from the air-fibre mixture through air discharge openings; passing extracted air through a micro dust removal means fixed to bottom chamber of said feed chute; characterized in that, air stream is passed through moving filter means orthogonally placed to the direction of the air stream wherein said moving filter means is continuously cleaned by passing the said filter means through a pair of pressing rollers and stripping knives.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates side view of a fibre feeder attached to a carding machine and fitted with micro dust removal device according to an aspect of the present invention.

Figure 2 illustrates top view of the feed chute fitted with a micro dust removal device according to an aspect of the present invention.

Figure 3 illustrates an enlarged side view of the micro dust removal device attached to feed chute according to an aspect of the present invention.

Figure 4 illustrates an enlarged view of the extraction arrangement according to an aspect of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention may be better understood and further advantages and uses thereof more readily apparent, when considered in view of the following detailed description of exemplary embodiments, taken with the accompanying drawings. These embodiments describe only a few of the various ways in which the principles of various other embodiments may be realized and the described embodiments are intended to include all such embodiments and their equivalents and the reference numerals used in the accompanying drawings correspond to the like elements throughout the description.

Figure 1 illustrates side view of a fibre feeder attached to a carding machine and fitted with micro dust removal device according to an aspect of the present invention. The Fibre feeder (FF) is attached to the carding machine (CM). The fibre feeder (FF) comprises a vertical chute (1) connected to the main fibre conveying duct (2) which is disposed for the transport and feeding of the fibre material from the feeding area with the help of air. At the lower end of the vertical chute (I), feed roller (3) and opening roller (4) are arranged. The feed roller (3) enables feeding of the fibre material downwards and opening roller (4) enables opening of the fibre material. A feed chute (5) is arranged downstream of the feed roller (3) and opening roller (4). The feed roller (3) and the opening roller (4) are driven by the drive system (not shown) of the fiber feeder (FF) for the controlled feeding of the mixture of fibre material and air to the feed chute (5).

Figure 2 illustrates top view of the feed chute fitted with the micro dust removal arrangement, The micro dust removal arrangement (MR) comprises a moving filter which is an endless flexible porous member which may be for example a perforated belt (9), means for driving the perforated belt (9) and an extraction means (EA). The perforated belt (9) is air permeable and constructed with predetermined porosity capable of retaining the fibre flies, dust and short fibres over its surface. The perforated belt (9) is guided through a plurality of positively driven rollers (10) drivably connected to the drive system of the fiber feeder (FF) to provide drive to the perforated belt (9) in the direction of the arrow shown. The perforated belt (9) is disposed downstream of the air discharge openings/perforations (6) and arranged inside the suction hood (7). The perforated belt (9) covers the entire width of the discharge openings/perforations (6). The plurality of extraction arrangement (EA) is disposed at the exit portion of the perforated belt (9) to strip and evacuate the fibre flies, dust and short fibres that are stuck to the surface of the perforated belt (9).

Figure 3 illustrates side view of the micro dust removal device attached to a feed chute. The walls of the feed chute (5) is provided with air discharge openings/perforations (6) arranged across the entire width of the feed chute (5). The air discharge openings/perforations (6) are arranged at a certain height in the lower portion of the feed chute (5). The air extracted through the air discharge openings/perforations (6) is conveyed to the upper end of the feed chute (5) through at least one suction hood (7) attached with a fan arrangement. The suction hood (7) is arranged adjacent to the feed chute (5) and is disposed for the conveyance of the extracted air to the upper end of feed chute (5). The fibre material from the opening roller is then transferred to a feed chute (5) wherein air present in the mixture is extracted through atleast one micro dust removal device (MR) and the fibre material which is free from air is delivered to a carding machine (CM) through a pair of driven feed rollers (8, 8'). In order to extract the air from the mixture of fibre material and air, the walls of the feed chute (5) are provided with air discharge openings/perforations (6) arranged across the entire width of the feed chute (5).

Figure 4 illustrates an enlarged view of the extraction arrangement (EA). The extraction arrangement (EA) comprises a pair of pressing rollers (11, 11'), stripping knives (12, 12') and a housing (13) fitted with a mouthpiece (14). The pressing rollers (11, IT) are arranged downstream of the air discharge openings/perforations (6) and permits free passage of the perforated belt (9) in between them. The stripping knives (12, 12') are arranged adjacent to the pressing rollers (II, IP) to the entire height of the perforated belt (9) on its both sides for the removal of the fibre flies, dust and short fibres clogged on the surfaces of the perforated belt (9). The pressing rollers (11, W) and stripping knives (12, 12') are arranged within the housing (13) which is also fitted with a mouthpiece (14). The mouthpiece (14) is provided for establishing connection to a suction source for the removal of the fibre flies, dust and short fibres stripped from the surfaces of the perforated belt (9) by the stripping knives (12, 121). The housing (13) is provided with an opening for the passage of the perforated belt (9), The surface of the perforated belt (9) emerging from the extraction arrangement (EA) may be cleaned with the help of jet of air, if required.

This arrangement according to the invention ensures the removal of the fibre flies, dust and short fibres from the extracted air and prevent it from getting passed into the feed duct along with the re-circulation air. This enhances the quality of the sliver produced by the carding machine. Further the invention facilitates the flexible porous membrane (9) with perforations substantially free from obstructions which ensures effective removal of fibre flies, dust and short fibres from the re-circulated air.

In view of the present disclosure which describes the current best mode for providing apparatus and a method for separating fibre flies, dust and short fibres from re¬circulating air stream, many modifications and variations would present themselves to those skilled in the art without departing from the scope and spirit of this invention. All changes, modifications and variations coming within the meaning and range of equivalency are considered within the scope.

We claim:

1. An apparatus for separating fibre flies, dust and short fibres from the air stream re-circulating from air discharge openings (6) in a feed chute (5) of a fibre feeder (FF) wherein said apparatus has at least a moving filter means (9) for filtering said air stream.

2. An apparatus as claimed in claim 1, wherein said moving filter (9) is a flexible porous membrane.

3. An apparatus as claimed in claim 2, wherein said flexible porous membrane is a perforated belt which is continuously moved through a plurality of positively driven rollers (10).

4. An apparatus as claimed in claim 1, wherein said moving filter (9) is placed orthogonally to the direction of the discharging air stream to be filtered.

5. An apparatus as claimed in claim 1, wherein an extraction means (EA) is provided for evacuating said fibre flies, dust and short fibres from the surface of said moving filter (9).

6. An apparatus as claimed in claim 5, wherein said extraction means (EA) comprises plurality of pressing rollers (11, 111) and plurality of stripping knives (12S 12') for removing fibre flies, dust and short fibres clogged on the surface of said moving filter (9).

7. An apparatus as claimed in claim 6, wherein said extraction means (EA) comprises a housing (13) enclosing said stripping knives (12, 12') and pressing rollers (I I, 11') and having a mouthpiece (14).

8. An apparatus as claimed in claim 6", wherein said pressing rollers (11,11') are placed downstream of said air discharge openings (6) and allows free passage of said moving filter (9) there between.

9. An apparatus as claimed in claim 6, wherein said stripping knives (12, 12') are placed adjacent to the pressing rollers (11, IT) and cover the entire height of the moving filter (9).

10. A method for separating fibre flies, dust and short fibres from the air stream
re-circulating from air discharge openings (6) in a feed chute (5) of a fibre feeder (FF) comprising the steps of : providing fibre material to a conveying duct (2); transporting fibre material and air along a vertical chute (I); transferring fibre material from feed roller (3) to a opening roller (4) and finally to a teed chute (5); extracting air from the air-fibre mixture through air discharge openings (6); passing extracted air through a micro dust removal
means fixed to bottom chamber of said feed chute (5); characterized in that, air stream is passed through moving filter means orthogonally placed to the direction of the air stream wherein said moving filter means is continuously cleaned.