Textile Machine Fiber Waste Disposal System

Abstract

A pneumatic conveyor extending from a plurality of textile machines is connected to a filter separator unit in which a momentary reverse flow of air through the filter is established periodically to clean the filter. Means are provided for automatically obstructing the pneumatic conveyor against the reverse flow of air therethrough, and other means are provided for automatically opening the filter separator unit to the discharge of collected fiber waste therefrom, whenever the reverse flow of air occurs and in response thereto.

Description

This invention relates to improvements in systems for pneumatically conveying and disposing of bulk fiber waste in textile plants, and the primary object of this invention to provide means for positively obstructing the flow of air from a filter separator unit back into the pneumatic conveyor when a reversely flowing airstream is utilized for cleaning the filter.

It is a more specific object of this invention to provide damper means responsive to the reverse flow of air through a filter in a fiber waste collection box for obstructing the reverse flow of air along an associated pneumatic conveyor duct, extending from a plurality of textile machines to the collection box, during periodic filter cleaning intervals.

It is still another object of this invention to provide apparatus of the character described wherein the collection box is provided with a discharge opening in its lower portion below the filter, and wherein such discharge opening is normally closed during production of the fiber conveying airstream within the pneumatic conveyor duct, with means responsive to the reverse flow of air for opening the normally closed discharge opening to the egress of fiber waste therethrough for emptying the same while permitting the reverse flow of air to exhaust from within the collection box through the discharge opening.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

FIG. 1 is a schematic layout of an embodiment of the fiber waste disposal system of the instant invention showing pneumatic conveyor means connecting a group of textile machines, in the form of carding machines, to the improved filter separator unit;

FIG. 2 is an enlarged fragmentary vertical sectional view through the filter separator unit in the lower central portion of FIG. 1 and showing the airflow through the inclined filtering medium thereof during the filtering of fiber waste from the conveying airstream;

FIG. 3 is a fragmentary somewhat schematic elevation of the filter separator unit shown in FIG. 1, but showing the airflow through the filtering medium in the reverse direction for dislodging from the filtering medium waste adhering thereto;

FIG. 4 is a fragmentary top plan view of the filter separator unit of FIG. 1 with the top wall or cover thereof removed; and

FIG. 5 is an enlarged fragmentary view of the closure element of the collection box discharge opening shown in FIG. 2 and showing the closure element in open position.

This invention is concerned with improvements in apparatus of the type disclosed in the copending U.S. Pat. application of James Aubrey Wild, Ser. No. 595,201 filed Nov. 17, 1966 and entitled FIBER WASTE DISPOSAL SYSTEM FOR TEXTILE MACHINES, of common assignee. The fiber waste disposal systems of the present invention and that disclosed in said copending application are devised for removing fiber waste (fibers, lint, motes, dust and/or other light and finely divided materials) from the vicinity of a plurality of textile machines, each being generally designated at 10 in FIG. 1. Such machines generate fiber waste as an incident to the operation thereof and are shown in the form of carding machines, each of which may be equipped with an individual pneumatic cleaning system substantially of the type disclosed in said copending application. Reference also is made to Reiterer's U.S. Pat. No. 3,150,415 for disclosure of a pneumatic cleaning system associated with a carding machine.

The fiber waste from various areas of each carding machine is deposited within the lower portion of such machines and each machine is equipped with a suction blower 11 (FIG. 1) for blowing the lint from one end of each machine to the other. The lower portions of the carding machines 10 are communicatively connected to a common pneumatic conveyor or air inlet duct 16 extending to a central collection area defined by a filter separator unit or collection box broadly designated at 20. Collection box 20 is generally of the type disclosed in said copending application and has duct 16 communicatively connected to the upper portion thereof, serving as an air inlet therefor.

Preferably, but not necessarily, the air inlet of collection box 20 is disposed in opposing alignment with an air outlet defined by an outlet duct 22 communicatively connected to that end wall of collection box 20 opposite from duct 16. The upper portion of collection box 20 serves as an expansion chamber, and positioned therein is an inclined filtering medium or filter screen 23, hereinafter referred to as a "filter." Filter 23 is positioned so that fiber waste in the airstream entering collection box 20 impinges against filter 23, as the airstream flows through filter 23 and the outlet, so as to permit some of the fiber waste to gravitate from the filter into the subjacent portion of the housing of collection box 20.

The upwardly facing downstream surface of filter 23 is subjected to suction from one or more fans, preferably of the axial-flow type, and serving as normally active means producing a fiber conveying flowing airstream adjacent the textile machines, along pneumatic conveyor 16 and into collection box 20. For example, a group of three successively arranged axial-flow fans 25, 26, 27 are positioned in outlet duct 22 for producing the fiber conveying airstream. Fans 25, 26, 27 are driven by respective electric motors 25', 26', 27' and may be controlled by a switching and timing device 28 electrically connected to motors 26', 27', 28' as shown schematically in FIG. 2.

The lower wall portions of collection box 20 are inclined and converge downwardly to define the lower portion of a collection area or hopper 30 below filter 23. Hopper 30 is provided with a bottom discharge opening 31, preferably of substantially rectangular configuration, which is opened and closed automatically in alternation in accordance with the direction of flow of air through filter 23, as will be later explained.

Hopper 30 is supported by and positioned partially within the upper portion of an enclosure 34 resting upon the floor F. Enclosure 34 may be of such size as to accommodate therewithin a wheeled bin 35 which may be moved into and out of an enclosure 34 through a suitable opening normally closed by a hinged or otherwise movable door 36 in the front wall 34a of enclosure 34. When wheeled bin 35 is positioned within enclosure 34 (FIGS. 1 and 3), at least a portion thereof extends beneath hopper discharge opening 31 that fiber waste within hopper 30 may be emptied directly into wheeled bin 35.

According to the invention, the emptying of the contents of hopper 30 into wheeled bin 35 is augmented by a reverse flow of air through filter 23, as will be later described. Therefore, the front and rear walls 34a, 34b of enclosure 34 may be provided with screened openings 34c, 34d to permit air to escape from enclosure 34 during the outward flow of air through discharge opening 31 while preventing fiber waste from escaping from enclosure 34.

Switching and timing device 28 may be of the type disclosed in said copending application and represents automatic control means for periodically and at controlled intervals inactivating fans 25, 26, 27 producing the fiber waste conveying airstream and momentarily effecting a reverse flow of air through filter 23 for a period of relatively short duration sufficient to dislodge from filter 23 fiber waste adhering thereto, and for thereafter stopping the reverse flow of air and reactivating fans 25, 26, 27 to perform their normal function.

Obviously, the duration of each interval of forward flow of airstream through filter 23 is dependent upon the amount of fiber waste being generated as an incident of the operation of the textile machines 10. For example, each interval of forward flow of the airstream through the filter may be about 10 to 60 minutes and each filter cleaning cycle may be effected in about 8 to 12 seconds. After fans 25, 26, 27 have rotated in the forward direction for a substantial period of time, a thin light film or mat of fiber waste may form over the downwardly facing surface of filter 23. At predetermined periodic intervals established by switching and timing device 28, and before the fibrous mass has built up against filter 23 to such extent as to undesirably impede the flow of air therethrough, fan motors 25', 26', 27' are automatically switched off and allowed to run down for about 2 to 3 seconds, for example. Then motors 25, 26, for example, are switched on to drive fans 25, 26 in the reverse direction for a short period of about 2 to 3 seconds, for example; sufficient to reverse the pressure differential on the two sides of filter 23 and to clean the same as the reverse-flowing airstream enters collection box 20 and passes through filter 23 into hopper 30, as represented by the arrows in FIG. 3. Thereafter, the two fans 25, 26 are allowed to run down for about 2 to 3 seconds, and then all the fans are restarted in the forward direction. One or more or all the fans 25, 26, 27 may be reversed during each filter cleaning cycle.

According to the invention, novel means are provided in response to the reverse flow of air through filter 23 for automatically obstructing the reverse flow of air along airflow duct 16 during the cleaning of filter 23 to thereby positively obstruct the reverse flow of air and fiber waste through duct 16 and at the textile machines 10, which means is effective automatically to permit forward flow of the fiber conveying airstream from the machines 10, through collection box 20 when fans 25, 26, 27 are being rotated in the forward or normal direction. Also, means are provided for automatically opening hopper discharge opening 31 to the discharge of fiber waste from hopper 30 in response to the reverse flow of air through filter 23. The latter means is also responsive to the forward flow of the airstream through filter 23 for closing hopper discharge opening 31.

In its preferred embodiment, the means for obstructing the reverse flow of air through air inlet duct 16 comprises an airflow obstructing element or damper 45, which is preferably imperforate and is preferably in the form of a substantially rectangular plate. Damper 45 is pivotally connected at its upper portion to the upper wall of air inlet duct 16 adjacent collection box 20. The lower wall of air inlet duct 16 has a suitable limiting abutment 46 suitably secured thereto and positioned adjacent the normally upstream side of damper or flap 45. During normal operation, in which the airstream is flowing in a forward direction and conveying fiber waste from the machines 10 into collection box 20, the forwardly flowing airstream impinges against and holds damper 45 in a substantially open position, as shown in FIGS. 1 and 2, so that the airstream and fiber waste borne thereby readily flow past damper 45 and into collection box 20. However, during each filter cleaning cycle, the reverse flow of air through filter 23 impinges upon the face of damper 45 adjacent collection box 20 and quickly moves damper 45 to fully closed position against limiting abutment 46.

In its preferred embodiment, the means for opening and closing hopper discharge opening 31, as best shown in FIG. 5, is in the form of a closure member or closure flap 50 pivotally connected to one sidewall of discharge opening 31, preferably by means of a plurality of metal rings 51. Only one of the rings 51 is shown extending through the latter sidewall and loosely penetrating one edge portion of closure flap 50. When closure flap 50 occupies the closed position shown in FIGS. 1 and 2, it may engage the lower edges of all the walls of hopper discharge opening 31 so as to prevent fiber waste from dropping through opening 31 at least during such times as wheeled bin 35 may be removed from within enclosure 34 for emptying the contents thereof at another location.

To ensure that the forward flow of air through collection box 20 is effective to suck the freely suspended closure flap 50 to closed position following each time that fiber waste in hopper 30 is emptied into wheeled bin 35, closure flap 50 may be made from relatively lightweight, thin rigid sheet or corrugated material and, additionally, means are provided for limiting the extent to which closure flap 50 may move to open position. To this end, at least one side, and preferably both sides, of discharge opening 31, are provided with an extension plate or skirt 53 having a plurality of vertically spaced holes 54 therein (FIG. 5). A pin or other suitable abutment 55 may be positioned in any one of the holes 54 for limiting the extent to which closure flap 50 may be opened.

The position of abutment 55 is dependent upon the amount of suction pressure produced by the forwardly flowing airstream within the lower portion of collection box 20. Although the effectiveness of the relatively low pressure within the lower portion of hopper 30 and acting upon the upper surface of closure flap 50 may be reduced as fiber waste accumulates in the hopper, natural cohesion of textile fibers then will prevent the mass of fibers in hopper 30 from pressing against closure flap 50 with sufficient force to move the same to open position before another filter cleaning cycle is effected.

At substantially the same time that the reverse flow of air attendant to a filter cleaning cycle moves airflow obstructing damper 45 to closed position in the manner heretofore described, the reverse flow of air, having nowhere else to go, builds up a positive pressure within collection box 20 such as to forcibly discharge the collected fiber waste through hopper discharge opening 31 while aiding closure flap 50 to gravitate to an open position in engagement with the limiting abutment 55 in skirt 53.

It is thus seen that I have provided means for automatically obstructing a pneumatic conveyor to the reverse flow of air therealong when a normally forwardly flowing, fiber conveying, airstream is reversed to clean a filter in an associated collection box, and wherein I have provided means responsive to such reverse airflow for automatically opening a normally closed fiber waste discharge opening in the lower portion of the collection box below the filter to not only aid in emptying the collection box, but to also permit the reverse flowing airstream to escape from the collection box.

In the drawings and specification there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation.

Claims

I claim:

1. Apparatus for disposing of substantial amounts of textile fiber waste generated as an incident of the operation of a plurality of textile machines which apparatus comprises a collection box having an air inlet and an air outlet positioned in substantial alignment, a pneumatic conveyor including at least one airflow duct extending from the machines to said inlet, fan means positioned in said air outlet for producing a fiber-conveying airstream within said airflow duct to convey fiber waste laden air from the machines to said collection box, an inclined filter within said box and interposed between said inlet and said outlet, said filter being so positioned that fiber waste in said airstream impinges against said filter and is separated from the airstream flowing through said filter and through said outlet, control means for periodically reversing said fan means for causing a momentary reverse flow of air in said box through said filter to clean said filter by dislodging fiber waste therefrom and to assist it in gravitating into the subjacent portion of said box, and means responsive to said reverse flow of air from said fan means for effecting obstruction of the reverse flow of air along said airflow duct during cleaning of said filter to thereby substantially prevent reverse flow of air and fiber waste at the textile machines.

2. Apparatus according to claim 1, wherein said responsive means comprises a movable flap within said airflow duct and occupying open position during production of said fiber-conveying airstream, and said flap being movable to closed position under influence of said reverse flow of air.

3. Apparatus according to claim 2, wherein said flap is pivotally mounted in said airflow duct and is biased to open position under influence of said fiber-conveying airstream, and said flap being movable to closed position by impingement of said reverse flow of air thereagainst.

4. Apparatus according to claim 1, wherein said collection box is provided with a discharge opening in its lower portion below said filter, and wherein said discharge opening is normally closed during production of said fiber-conveying airstream within said airflow duct, and means responsive to said reverse flow of air for opening said discharge opening to the egress of fiber waste therethrough.

5. Apparatus according to claim 4, wherein said means responsive to said reverse flow of air for opening said discharge opening comprises a closure flap pivotally mounted adjacent said discharge opening and normally biased toward closed position by relatively low pressure effected within the lower portion of said collection box by the flow of said fiber-conveying airstream from said inlet through said filter and said outlet, and said closure flap being movable to open position by an increase in air pressure within said housing as produced by said reverse flow of air.

6. Apparatus according to claim 1, in which said fan means for producing a fiber-conveying airstream within airflow duct comprises a plurality of fans positioned in said air outlet and normally rotating in a forward direction, and said control means for periodically causing a momentary reverse flow of air in said housing including means for interrupting the rotation of all said fans and momentarily reversing at least one of said fans.

7. Apparatus for disposing of textile fiber waste of substantial volume generated as an incident of the operation of a plurality of textile machines comprising a central collection box remote from said machines and having an air inlet and an air outlet spaced from said inlet, said air inlet and air outlet being in substantial alignment, a pneumatic conveyor including at least one airflow duct communicatively connecting the textile machines to the air inlet of said collection box and for receiving fiber waste from the machines, fan means positioned in said air outlet for producing a fiber-conveying flowing airstream within the pneumatic conveyor for conveying fiber waste laden air from said machines to said collection box, an inclined filter positioned within said box and being so positioned with respect to the waste laden air flowing into said box as to cause fiber waste to impinge thereupon and be separated from the air flowing through said outlet, control means for periodically reversing said fan means for causing a reverse flow of air from said outlet of said box through said filter to dislodge fiber waste adhering thereto and to assist it to fall away from said filter into the subjacent portion of said collection box, damper means responsive to said reverse flow of air from said fan means for effecting obstruction of the reverse flow of air along said airflow duct during cleaning of said filter to thereby substantially prevent reverse flow of air and fiber waste at the textile machines, said collection box having a discharge opening in its lower portion below said filter, closure means normally closing said discharge opening against the discharge of fiber waste therethrough during production of said fiber-conveying airstream within said pneumatic conveyor, and said closure means being movable to open position in response to said reversing of said fan means and the reverse flow of air through said filter whereby fiber waste in said collection box is discharged through said discharge opening.

8. A structure according to claim 7, wherein said closure means comprises a closure flap pivotally mounted adjacent one edge of said discharge opening, means limiting the extent of pivotal movement of said closure flap to open position, and said closure flap being so positioned as to move to closed position under influence of said fiber-conveying airstream flowing through said filter and said outlet.