Title of Invention

FILTERING APPARATUS WITH A COLLECTING ELEMENT

Abstract

The invention concerns a filtering apparatus (1) for separating fibres and/or dust from an air stream with a separating device comprising a head portion (7) into which an air inlet tube (5) merges tangentially, and with an air permeable hollow filter (10) arranged below the head portion (7), and adjacent to the lower outlet opening (16) of which filter a collecting element (18) is co-ordinated. Known arrangements tend to accumulate contamination and are not maintenance-free. An apparatus thus is proposed in which the collecting element (18) in its upper limiting wall (24) is provided with an inlet opening (15) the cross-sectional area of which roughly equals the one of the outlet opening (16) of the hollow filter (10), and which faces the latter, and that means (21) are provided restricting the inlet opening (15) to an annular throughput opening (20) to the collecting element (18).

Full Text

Filtering Apparatus The present invention concerns a filtering apparatus for separating fibres and/or dust from an air stream with a separating device comprising a head portion into which an air inlet tube merges tangentially, and with an air permeable hollow filter arranged below the head portion to the lower outlet opening of which filter a collecting element is co-ordinated. From the EP-A1 691 428 a filtering device of such type is known in which the air loaded with dust and fibres is blown tangentially in via a supply tube into a head portion. Below the head portion in this arrangement a cylindrical hollow filter is arranged which is air permeable. The air in this arrangement can escape via the sieve envelope of the hollow filter fibres and dust carried on being held back at the inside surface of the sieve envelope and being taken off downward. They are transferred into an enclosed ring wall section and on from there via an opening into a collecting recipient. The collecting recipient can be laid out as a drawer or as shiftable carriage. The cross-sectional area of the ring wall secfion corresponds to the cross-sectional area of the hollow filter. The ring wall section at its lower end is provided with a wall in which an outlet opening for the collected particles is provided. This outlet opening leading towards the collecting recipient covers merely a small portion of the cross-section of the ring wall section and is combined partially with an impacfing wall. Using this arrangement dust and fibre fly waste already deposited in the collecting recipient are prevented from being sucked back again in a resulting counter-current upward into the zone of the filter envelope, but this arrangement presents disadvantages with respect to contamination of the zone of the outlet opening. The contaminated air being blown in tangentially into the head portion an air flow is generated which spirals down essentially in the zone of the outer wall of the separator. A good portion of this air then is drained ofi" via the hollow cylinder the remaining air containing the fibres and dust separated being transferred into the zone of the outlet opening. The outlet openings shown here are chosen relafively small and are present edges oriented at a bias to the spiral air flow. Thus there is the danger that fibres cling to these edges in such a manner that further accumulation of clinging fibres and dust is favoured. Such deposits eventually can result in a partial clogging of these outlet openings. Thus, in order to maintain functionality in this arrangement periodic cleaning must be performed. From the DE-A1 35 27 656 a filtering device Is known in which for cleaning the filtering surfaces particular sweeper elements operated via cylinders are provided. Furthermore from the DE-A1 29 10 564 a separating device for fibres and dust is known in which two concentrically arranged hose filters are provided. This arrangement is conceived in particular for separating the fibres carried in the air stream separately from the dust particles present in the air stream. The porosity of the inner filter hose in this arrangement is greater than the one of the outer filter hose. In this manner separation of the fibres is to be effected at the inner filter hose whereas the dust particles penetrate the inner filter sleeve and are held back by the outer filter sleeve. Elimination of the fibres separated downward as well as elimination of the dust particles carried down into a funnel are effected in two steps, and using different collecting vessels. No measures are taken here for suppressing a flow-back of fibres already separated downward via an uncontrolled air flow into the zone of the filter body. Based on the state of the art described the objective of the present invention thus is to propose a simple filtering apparatus for separating of fibres and dust particles not requiring much maintenance. In this arrangement uncontrolled flow-back of fibres and dust particles already deposited In a collecting vessel back to the filtering element is to be suppressed and deposits and contamination in the zone of the filtering apparatus is to be prevented to a large extent. This objective is achieved in that the collecting element in its upper limiting wall is provided with an inlet opening the cross-sectional area of which is about equal to the cross-sectional area of the outlet opening of the hollow filter, is arranged opposite to the latter, and In that means are provided which restrict the inlet opening to an annular through-pass opening to the collecting element. In this arrangement on one hand uncontrolled flow-back of fibres and dust already deposited in the collecting element is suppressed and on the other hand owing to the annular iay-out of a trough-pass opening clinging and adhesion of fibres and dust particles in the zone of the through-pass opening are prevented. Owing to the annular through-pass opening no edge oriented at a bias with respect of the air circulation is present. It is proposed that the means is arranged essentially at the centre of the inlet opening where this means can be formed as a disk arranged about centrally with respect to the periphery of a circular inlet opening. In this arrangement the disk is of a smaller diameter than the inlet opening. In order to ensure unhampered through-pass of longer fibres carried on via the annular through-pass opening and, on the other hand, to suppress uncontrolled flow-back it is proposed that the distance left free between the disk and the circular inlet opening ranges between 20 mm and 80 mm and preferentially is 50 mm. Furthermore a device is proposed in which an upper limiting wall of the collecting element - seen in horizontal direction - exceeds the cross-sectional area of the outlet opening of the hollow filter and in which the means is formed as a disk the diameter of which exceeds an inlet opening of circular shape and is arranged below, and at a distance from, the upper limiting wall of the collecting element. Preferentially the distance from the upper limiting wall in this arrangement is chosen ranging between 20 mm and 80 mm, or preferably 50 mm respectively. Using this arrangement also suppression of uncontrolled upward air flows and unhampered downward through-pass also of long fibres carried in the air are ensured. The upper limiting w/all of the collecting element can horizontally exceed the outlet opening of the hollow filter also in the aforementioned design example in which the disk is arranged centred in the inlet opening. Furthermore It is proposed that the hollow filter tapers off in its cross-section, seen in the direction towards its outlet opening, and is formed as a truncated cone respectively. In this arrangement the ratio of the cross-sectional areas of the inlet opening and the outlet opening of the hollow filter can range between 1.4 to 1 and 1.1 to 1, and preferentially is chosen as 1.2 to 1. Using this arrangement it is achieved that the hollow filter is subject to a self-cleaning effect owing to the spiralling airflow. Conical lay-out of filter elements of such type Is described already in the DE-A1 35 40 688 and in the DE-A1 196 48 561, The conical lay-out in this arrangement is chosen in such a manner that on one hand a self-cleaning effect is achieved and that on the other hand deposits on the conical filter sleeve are avoided. This requirement implies that the taper of the conical filter is not to exceed a certain value. A particularly simple and cost efficient design lay-out is obtained if the hollow filter is made from an air permeable filter cloth which extends between the head portion and the collecting element is held under tension in its longitudinal direction. For regulating the air quantities and for influencing the power requirement of the air transporting fan it is proposed that the air inlet tube in the head portion, seen in its longitudinal direction and in the transporting direction, increases in Its cross-sectional area. This ensures that no counter-pressure Is acting against a fan arranged upstream, e.g. due to friction on the tube walls, in such a manner that the full power of the fan can be applied to the air transport. Preferentially a radial fan Is arranged upstream from this air inlet tube in the head portion. Furthermore it is proposed that the collecting element be provided with an exchangeable drawer. In this arrangement the means forming the aimular through-pass opening can be fastened to this drawer. In a further embodiment it is proposed that the collecting vessel be provided with at least one pivotable flap. It proves advantageous to arrange the hinge of the flap in the zone of the lower Hmit of the collecting element. This arrangement ensures that upon tilting down the flap simple cleaning of the easily accessible collecting element can be effected manually or machine assisted. Accordingly the present invention provides a filtering apparatus for separating fibres and/or dust from an air stream using a separating device comprising a head portion into which an air inlet tube merges tangentially and, arranged below the head portion, an air permeable hollow filter adjacent to the lower outlet opening of which a collecting element is co-ordinated, characterized in that the collecting element is provided with an inlet opening the cross-sectional area of which roughly equals the one of the outlet opening of the hollow filter, and which is arranged opposite the latter, and that a disc is provided which restrict the inlet opening to an annular throughout opening to the collecting element. Further advantages are shown and described in more detail in the following with reference to illustrated design examples. It is shown in the: Fig. 1 A schematic side view of a filtering apparatus, Fig. 2 A schematic top view according to the Fig. 1, Fig. 3 A schematic part view according to the Fig. 1 in the zone of the collecting element with a ixiither variant embodiment, and in the Fig. 4 A schematic part view according to the Fig. 1 with a further variant embodiment. In the Fig. 1 a filtering apparatus 1 is shown upstream from which a radial fan 2 is arranged. The radial fan 2 is provided with an inlet tube 4 via which the air carrying dust and fibre debris is fed to the radial fan. This air stream can be supplied e.g. fi-om a textile machine in which at various locations suction ducts are arranged in order to keep the machine, or the machine elements respectively, clean. Via an outlet tube 5 (compare also the Fig. 2) arranged substantially tangentially on the radial fan 2 the contaminated air is blown radially into an enclosed head portion 7 of substantially cylindrical form of the filtering apparatus 1. As can be seen in the Fig. 1 particularly the cross-sectional area of the tube 5 slightly increases fi-om the outlet of the radial fan 2 to the inlet of the head portion 7. Owing to this arrangement unhampered air flow without any build-up of counter-pressure (which could be caused by friction in the tube 5) is to be ensured in the transfer to the head portion 7. This allows utilisation of the energy consumed by the fan 2 for the air transport without noticeable losses. Adjacent to the head portion 7 which at its lower end is provided with an opening of a diameter D1 a hollow filter 10 is arranged which using a clamping element 12 is fastened to the head portion 7. The hollow filter 10 is equipped with a fine mesh filter cloth 11 and tapers off under an angle a all the way to its outlet opening 16 which corresponds to an inlet opening 15 of an adjacent collecting box 18. The outlet opening 16 and the inlet opening 15 each are of a diameter D2. The filter doth 11 at its lower end in the zone of its outlet opening 16 is fastened to an annular flange 19 of the collecting box 18 using a schematically shown clamping element 13. The clamping elements 12 and 13 are provided with releasable locking devices (not shown). Concentrically with the inlet opening 15 a disk 21 supported by a holding rod 22, which in turn is mounted onto the floor of the collecting box 18, is arranged in the zone of the flange 19. The disk 21 is of a diameter D and together with the inlet opening 15 of the diameter D2 forms an annular throughput opening 20 of a width a. In the following the function of this apparatus now will be described briefly: The air charged with dust and fibre particles aspired via the tube 4 into the radial fan 2 is blown into the head portion 7 via the tube 5. The air stream then spirals down along the inner wall of the head portion 7 and reaches the inner surface of the filter cloth 11 of the hollow filter 10. In the zone of this hollow filter 10 the air can penetrate the filter cloth 11 and for the most part is given off to the surrounding room outside as indicated schematically by the arrows shown with dashed lines. The dust and fibre particles are held back on the inner surface of the filter cloth 11 and are eliminated downward towards the collecting box 18. There the particles separated reach the zone of the throughput opening 20 and are transferred to the inside of the collecting box 18. Eventual flow-back, indicated schematically by the arrows shown, is suppressed by the disk 21. In this arrangement the fibre and dust particles already deposited in the collecting box 18 are prevented from returning upward Into the zone of the hollow filter 10 and from landing on the filter cloth 11 again. In this manner a maintenance-free filtering apparatus is created. Owing to the tapered (angle cc) layout of the hollow filter 10 the inner surface of the filter cloth 11 presents a certain resistance to the air stream moving downward. This results in a brushing effect exerted by the air stream in such a manner that the filter cloth is subject to a so-called self-cleaning action. The design of the head portion 7 and of the filter box 18 is laid out in such a manner that the filter cloth, held in place by the clamping elements 12 and 13, is slightly tensioned in longitudinal direction in its mounted state. Thus no wrinkles can form in the filter cloth 11 and the whole surface of the filter cloth remains accessible as a separating surface. Furthermore this prevents formation of depots. After a certain filling height level has been reached in the collecting box 18 the clamping element 13 can be released in such a manner that the collecting box is disconnected from the hollow filter 10. The collecting box then can be taken off and be emptied. For facilitating the emptying procedure it could be imagined that the disk 21 with the holding rod 22 be detachably mounted to the collecting box. Once the disk 21 is taken away the full width of the opening 15 is available for the emptying procedure. It could be imagined also that the collecting box 18 be provided with additional sealable openings for facilitafing performance of the emptying operation. Instead of the collecting box 18 also a waste bag could be applied which is detachably fastened in the zone of the outlet opening of the hollow filter 10. In an arrangement of this type the holding rod 22 fixing the position of the disk 21 could be arranged above the disk and could be fastened in the head portion 7. Using the arrangement described (not shown) for discarding accumulated waste merely an exchange of a filled waste bag against an empty one is to be effected. In the Fig. 3 the lower portion of the filtering apparatus 1 is shown schematically with a furtherembodiment of the present invention in the zone of the collecting box 18. In this arrangement a disk 26 is arranged at a distance a1 from the upper wall 24 of the collecting box 18, the diameter D3 of which disk exceeds the diameter D2 of the outlet opening 16, and of the inlet opening 15 respectively. The filter cloth 11 in this arrangement also is fastened to the flange 19 of the collecting box 8 using a clamping element 13. The dust and fibre particles separated in the zone of the inner surface of the filter cloth 11 are carried downward and via the vertically oriented annular throughput opening 28 of the width a1 are transferred to the inside of a drawer 30 inserted into the collecting box 18. In the collecting box 18 guide slides 32 are shown schematically on which the drawer 30 is guided as it is moved out or in. A sealing lip 34, schematically shown, surrounding the upper portion of the drawer 30 can be provided which, as shown, in the closed state of the drawer 30 sealirigly contacts the upper wall 24 of the collecting box 18. Owing to this arrangement the dust and fibre particles collected in the drawer 30 are prevented from reaching the other zones of the collecting box 18. Instead of on sliding guides the drawer 30 also could be moved in and out of the collecting box 18 on wheels (not shown) mounted onto the drawer 30. A similar arrangement is shown e.g. in the EP-A1-691 428 already cited above. This arrangement ensures that the drawer 30 alter a certain filling height level has been reached can be removed laterally from the collecting box without difficulty and without being obstructed by the disk 26 which, differing from the first embodiment described, is mounted below the upper wall 24. In the Fig. 4 a further design example is shown In which the disk 21, as in the first embodiment described according to the Fig. 1, is placed within the inlet opening 15 and is fastened to the floor of the collecting box 18 using a holding rod 22. The other elements and mounting elements in the zone of the flange 19 near the inlet opening 15 correspond to the ones shown in the design example shown in the Fig. 1 and thus are not described further here. New, compared to the design example according to the Fig. 1, is the provision of a flap 36 which can be tilted down pivoting about a hinge 37 as indicated with dashed lines. The collecting box 18 in this arrangement is placed on supports 38 and thus is distanced from the floor by a distance b. Thus the flap 36 can be pivoted down to a downward inclined position in such a manner that clearing the waste material accumulated from the collecting box 18 is facilitated. It can be imagined e.g. that a waste bag could be pulled on the tilted down flap into which bag the waste material then is shoved in manually. Using this arrangement it is possible on one hand to maintain the collecting box in its built-in position and on the " other hand to effect a simple and cost effective removal of waste material. The arrangements shown of the filtering apparatus shown present a simple and cost-effective apparatus for separating dust and fibre particles the function of which is reliable and, from an economical viewpoint, is applicable individually even in small machine units. 1. Filtering apparatus (1) for separating fibres and/or dust from an air stream using a separaGng devfce comprisfng a head portion (7) (nto whfch an a(r tnlet tube (5) merges tangentially and, arranged below the head portion (7), an air permeable hoHow filter (10) adjacent to the lower outiet opening (16) of which a collecting element (18) is co-ordinated, characterized in that the collecting dement (18) Is provided with an intet opening (15) the cross-sectional area of which roughly equals the one of the outiet opening (16) of the hollow filter (10), and which Is annnged opposite the latter, and that a disc (21) is provided whkh restrxi the inlet opening (15) to an annular throughout opening (20) to the collecting element (18), 2. Filtering apparatus as claimed in claim I, wherein the disc (21) is arranged essentially at the center of the inlet opening (15). 3. Filtering apparatus as claimed in claim 2, wherein the disc (21) which is arranged essentially centrally and at a radial distance from the periphery of a circular inlet opening (15). 4. Rltering apparatus as claimed in claim 3, wherein the radial distance ranges between 20 mm and SO mm and preferentially is 50 mm. 5. Rltering apparatus as claimed In claim 1, wherein an upper limiting wall (24) of the collecting element (18), seen in horizontal direction exceeds the cross-sectional area of the outiet opening (16) of the hollow fitter (10), and that the means is formed by a disc (26} the diameter (D3) of which exceeds an inlet opening (15) of circular form and which is arranged below, and at a distance (al) from the upper limiting waH (24) of the collecting element (IS). 6. Filtering apparatus as claimed in claim 5, wherein the distance (al) from the upper limiting wall (24) ranges between 20 mm and 80 mm, and preferentially is 50 mm. 7. Filtering apparatus according to one of the claims 1 through 6, characterized in that the hollow filter (10) tapers off in its cross-sectional area in the direction towards its outlet opening. 8. Filtering apparatus according to the claim 7, characterized in that the hollow filter (10) is of the form of a truncated cone. 9. Filtering apparatus according to one of the claims 7 or 8, characterized in that the ratio of the cross-sectional areas of the inlet opening (14) and the outlet opening (16) of the hollow filter (10) ranges between 1.4 to 1,0 and 1.1 to 1.0, and preferentially is 1.2 to 1.0. 10. Filtering apparatus according to one of the claims 1 through 9, characterized in that the hollow filter (10) consists of an air permeable filter cloth (11) which between the head portion (7) and the collecting element (18) is held under tension in its longitudinal direction. 11. Filtering apparatus according to one of the claims 1 through 10, characterized in that the cross-sectional area of the air inlet tube (5) in the head portion (7), seen in its longitudinal direction and in the transporting direction, increases. 12. Filtering apparatus according to one of the claims 1 through 11, characterized in that upstream from the air inlet tube (5) in the head portion (7) a radial fan (2) is arranged. 13. Filtering apparatus according to one of the claims 1 through 12, characterized in that the collecting element (18) is provided with an exchangeable drawer (30). 14. Filtering apparatus according to one of the claims 1 through 12, characterized In that the collecting element (18) is provided with at least one pivotable flap (36). 15. Filtering apparatus according to the claim 14, characterized in that the hinge (37) of the flap (36) is arranged in the zone of the lower limit of the collecting element (18). 16. A filtering apparatus, substantially as herein described, with reference to the accompanying drawings. . t V /}•

Documents:

0803-mas-1999 abstract.jpg

0803-mas-1999 abstract.pdf

0803-mas-1999 claims duplicate.pdf

0803-mas-1999 claims.pdf

0803-mas-1999 correspondence-others.pdf

0803-mas-1999 correspondence-po.pdf

0803-mas-1999 description (complete) duplicate.pdf

0803-mas-1999 description (complete).pdf

0803-mas-1999 drawings.pdf

0803-mas-1999 form-1.pdf

0803-mas-1999 form-19.pdf

0803-mas-1999 form-26.pdf

0803-mas-1999 form-3.pdf

0803-mas-1999 form-5.pdf

0803-mas-1999 petition.pdf