APPARATUS AND SEALING METHOD FOR USE IN A BAND TYPE FILTER
BACKGROUND OF THE INVENTION This invention relates generally to dust filters and collectors and, more particularly to apparatus of this type in general, which include some installations for sealing a filter medium in the form of a band as it moves through its cleaning cycle. There are many types of filters and dust collectors that include some forms of filter media through which transport air or other fluid that has dust or other foreign matter introduced into it, is passed to the deposit of foreign matter on the exposed surface of the filter medium and, in similar industrial and heavy load applications where the filtered foreign matter is collected on the surface of the filter medium at a relatively fast speed, it is desirable to provide the apparatus with some forms of automatic cleaning of the medium filter so that it can operate on a continuous basis. In some filters and dust collectors designed for industrial use, a suction nozzle is placed adjacent to the substrate surface of the filter medium to remove foreign or particulate matter collected therein, and then use the suction to transport the foreign matter or particulate away from the filter for collection and removal. In some filters of this type, a flat stationary filter or a rotating cylindrical filter is used, and a cleaning nozzle is moved across the surface of the filter medium to clean it, all as described, for example, in the Patent. American No. 4,725,292, from Williams. In other similar designs, the filter medium moves past a stationary suction nozzle. More recently, filters or dust collectors have been designed with the filter medium having a folded configuration and formed as an endless band that rotates in a generally elliptical path with either a suction nozzle, or a discharge device. air by impulse injection, or both, located in a curved section of the filter medium to remove foreign matter therefrom, all as set forth in greater detail in US Patent Application Serial No. 08 / 520,572, filed on 11 July 1995, now US Patent No., and its continuation United States Patent Application Serial No., filed. As discussed in greater detail in such patent applications, the fact that the filter medium moves along the housing which defines the clean air chamber of the filter apparatus may present problems in terms of proper sealing between the support housing and the movable filter means, whereby dirt or unfiltered air can pass directly to the clean air chamber around the edges of the movable filter medium without passing through the filter medium. SUMMARY OF THE INVENTION The present invention provides an improved installation for sealing the lateral edges of a moving substrate or filter medium. More specifically, the present invention includes a permeable substrate through which passes a transport fluid having foreign or particulate matter introduced therein, inward therethrough, to deposit such matter on the outer surface of the substrate, and a housing that includes a support structure for supporting the substrate to move it through a predetermined path. The support structure includes support surfaces positioned to support the edge portions of the substrate, and these support surfaces are formed with a suction channel extending therethrough below the edge portions of the substrate to delineate the surfaces of the substrate. portions of the edge of the substrate against such support surfaces to form a seal therebetween and remove particulate matter that could pass through the seal. The housing also includes at least one drive member for moving the substrate along its predetermined path, and a clean fluid chamber positioned in the interior portion of the substrate from which the transported fluid can be removed after it has passed through the substrate. A seal tape is provided on the substrate, and includes a portion formed of a flaccid material, placed adjacent to the aforementioned suction channels in the housing, and this flaccid portion is formed with a predetermined clearance relative to the substrate to cause the flaccid material is partially attracted within the suction channel to improve the seal formed therein. The portion of the flaccid material is preferably formed of a closed fabric, and, preferably, the tape includes a flat portion through which the flaccida portion overlaps therein and joins thereto at separate sites, and the length of the portions of the flaccid material between such separate sites is greater than the length of the flat portions between such separate sites to provide the aforementioned predetermined clearance. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevation view of a typical filter apparatus incorporating the sealing installation of the present invention; Figure 2 is an elevational view of the filter apparatus illustrated in Figure 1; Figure 3 is a detailed sectional view illustrating the substrate of the filter means mounted on its housing support in sealing relationship thereto; and Figure 4 is a detailed view of the sealing tape attached to the substrate to create a seal in the suction channels formed in the housing. DETAILED DESCRIPTION OF THE PREFERRED MODALITY Now seen in greater detail, a typical dust collector or filter apparatus 10 is illustrated in the accompanying drawings, and is described in greater detail in the aforementioned US Patent Application Serial.
Do not. . The filter apparatus 10 includes a housing 12 that supports a pair of pulleys 14 mounted to rotate on an axis 16 and a pair of lower synchronization pulleys 18 fixed to an air discharge tube 20 that is rotated using any drive motor installation convenient and conventional (not shown). An endless band of the filter medium 22 is formed with continuous folds 22 'and has a pair of separate synchronization bands secured thereto, the synchronization bands 24 being clisable with the upper and lower pulleys 14, 18 so that the rotation of the lower timing pulleys 18 by the air discharge tube 20 results in a movement of the filter medium 22 in the elliptical path illustrated generally in Figure 2. As described in greater detail in the Patent Application US Series No., above, a suction nozzle 26 is placed in the lower circular portion of the filter medium 22 to remove foreign matter or particulate material collected on the outer surface of the filter medium 22 as it moves beyond the suction nozzle 26, and a pulse-reactor system, the details of which do not matter for the present invention, a control valve 28 is provided and included. operated by a two-way solenoid operated by a sensor 30 and a detection projection mounted on the rotating air discharge tube 20 to create a high pressure air pulse during each revolution of the air discharge tube 20. This impulse of Pressurized air is transmitted through the hollow air discharge tube 20 to generate a pressurized cleaning air pulse inside a hollow cylinder 34 having slots 36 formed therein through an arcuate portion 38 of the hollow cylinder 34 which is less than 180, and the pressurized air pulses generated through the slots 36 pass outwardly through the filter medium 22 as it moves through its lower curved section to remove particulate matter and foreign matter from the outer surface of the filter medium 22. The housing 12 is formed with the flat support surfaces 40 located on each side of the housing 12, and these surfaces extend to along the total vertical height of the filter apparatus 10 on both sides of a clean air chamber 42 located in the inner portion of the housing 12 and the filter medium 22, and the supporting surface 40 has curved portions at the upper ends and lower thereof to support the filter means 22 as it moves through its curved sections. According to the above, the supporting surface 40 remains adjacent to the outermost lateral edges of the filter medium 22 along its total generally elliptical extension. Each of the support surfaces 40 is configured to include a suction channel 44 that extends along the total length thereof below the side edges 46 of the filter means 22, and these suction channels can be connected to each other. the same suction source by the suction ducts 44 'connected to the suction nozzle 26.
According to the present invention, an improved sealing installation is provided which includes a seal and driver tape 48 secured directly to the filter means 22 adjacent to each of the side edges 46 thereof, preferably using continuous cords of molten metal. , and those ribbons 48 extend along the total continuous edge on both sides of the filter medium 22. Each belt 60 is formed of a thin, flexible, puncture-resistant abrasion-resistant material having a relatively low coefficient of friction, preferably a fabric of closed fabric, such as a polyester fabric covered with vinyl, and, as best illustrated in Figure 4, this material has a flat portion 52 and a portion with overlapping gap 54 that is folded back over one end of the flat portion 52 and are joined thereto at separate bonding sites 56. As best seen in Figure 4, the length of the clearance portion 54 between the two joined portions 56 is greater than the corresponding length of the flat portion 52 between such joined portions 56, whereby the clearance portion is capable of swelling away from the flat portion 52 of the way currently described. The other end of each flat portion 52 has a continuous Velero "hook" 58 tape stitched to the flat portion 52, and, as best illustrated in Figure 3, this Sailboat 58 tape can be selectively bonded and separated, from the aforementioned synchronization band 24 having a sailboat belt 60 cooperating thereon formed for clutch with the sailboat belt 58. The filter means 22 is supported on the housing 12 so that the clearance portion 54 of each of the sealing tapes 48 is placed through the upper open end of the suction channels 44 on each side of the housing 12. Accordingly, when a suction is imposed within the channels 50, this suction causes the Gap portion 54 of the sealing tape 48 swells outward from the flat portion 52 and is attracted towards the upper end of each suction channel 44 with the outer surfaces of the play portions 54 engaging the curved upper edges of the suction channels 44 over a substantial contact area (see figure 3) that provides a very effective seal between the movable filter means 22 and the fixed support surface 40 of the housing 12 to prevent dirty air from transport is infiltrated into the clean air chamber 42 at the side edges of the movable filter medium 22, and, if any dirty transport air passes through this seal it will be removed by suction in the suction channels 50. Therefore, , it will be readily understood by those skilled in the art that the present invention is susceptible of wide utility and application. Many embodiments and adaptations of the present invention other than those described herein, as well as many variations, modifications and equivalent arrangements, will be apparent or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope. of the present invention. In accordance with the foregoing, although the present invention has been described herein in detail in relation to its preferred embodiment, it is understood that this disclosure is illustrative and exemplary only of the present invention and is made solely for purposes of providing a complete disclosure. and enabler of the invention. The above disclosure is not intended or constructed to limit the present invention or otherwise exclude any other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention is limited only by the appended claims thereto and their equivalents.