Background of the Invention Field: This invention relates to filter presses, specifically those designed to separate solids from liquids. More particularly, this invention is directed to presses which utilize a fabric filter cloth as a means of removing solids from liquid systems.

Statement of the Art: Technical attention has long been devoted to the processing of solids-bearing liquids, such a slurries and other suspended solids systems. Of prominence amon the conventional means adopted to process these liquid-solid suspensions is the plate and frame filter press which typically includes a series of parallel, generally vertically oriented filter plates which are covered by a fabric filter cloth. The plates, during operation of the filter, are held in an abutting arrangement. In this arrangement, a plurality of enclosed space are defined between each pair of adjacently positioned plates. The liquid-solid suspension to be filtered is injected under pressure into the enclosed spaces. The suspension is forcibly directed through the filter cloths whereupon the solids within the suspension are deposited on the surface of the filter cloths Recognizably, after a period of operation, the cloths become sufficiently laden with solid deposits that further efficient operation of the press requires the plates to be separated and the solid deposits to be removed from the cloths.

In those instances wherein the solid deposits or filte cakes slightly or moderately adhere to the filter cloth, the mer opening of the abutting plates will often result in the cake falling off the filter cloths under the force of gravity. In those cases wherein the cake is in a sticky engagement with the filter cloth, other means are required to successfully separate the cake from the filter cloth.

A conventional approach to the cake having a sticky

engage ent with the filter cloth has been a physical removal of the cake from the cloth with a scraper. Noticeably, this approach involves a serious likelihood that the cloth may be damaged by the abrasive contact between the scraper and the clot 5 Further, provision of a scraper typically requires the employmen of a worker to manipulate that scraper. Various methods have also been proposed directed to automating the process of filter cake removal.

U.S. Patent No. 3,622,005 to Kurita discloses a frame

10 assembly adapted with means of suspending a filter cloth between each pair of the open filter plates. The cloth is suspended in modified inverted "V"-shaped configuration. The solids are deposited on the interior surfaces of the filter cloth forming the "V-shaped configuration, thereby initially permitting a

15. gravitationally induced removal of the cake from the filter clot surface. Thereafter, the disclosure suggests an oscillating or vibrational action being transferred to the cloth by means of a spring-biased actuation assembly.

U.S. Patent No. 3,669,273 to Kurita adopts a similar

20 vibration-based approach by providing a filter cloth suspension system which employs a cloth support which is vibrated by the motion of a spring associated with a superiorly positioned trolley which travels along a wave-like rail surface. This system utilizes a modified "V"-shaped suspension approach by

25 adopting a nonsymmetrical suspension support of the cloth in order to initiate the travel of the trolley along its rail.

In U.S. Patent No. 4,397,744 to Harvo, a vibrational motion is transferred to each inverted "V"-shaped filter cloth by means of a support arm having a series of wave-like undula-

30 tions in the surface thereof. The support arm is pivotedly filter plates are opened, i.e. separated, the support arm is pulled over a support which interacts with the undulated support arm surface to effect an oscillating motion to the support arm.

The support arm is linked through a spring to a rod supporting the filter cloth. As the support arm oscillates, the filter cloth is made to vibrate. In those instances wherein the filter cake is composed of a thioxotropic material, the addition of energy to the cake by a vibrational system may operate to complexify, if not hinder, the removal of the cake from the clot Specifically, thioxotropic material by definition tends to "puddle," i.e. become fluid upon the placement of shear forces o the mass of the material. In subjecting the cakes to vibrationa action, shear forces are generated on the cake at the interface of the cake and filter cloth, and further within the mass of the cake itself. It follows that vibration tends to transform portions of the cake into a fluid which often is more sticky in its adhesion or engagement with the filter cloth than the unvibrated cake.

In the event the vibrated cake develops fluidized pockets or strata within the cake itself, it is likely that the cake would slough off portions thereof as opposed to falling fro ^" the filter in toto. The disclosures of Kurita define mechanisms which induce a damped vibrational action within the suspended filter cloth, i.e. the vibration-inducing action of the actuatin apparatus is translated to the filter cloth through means of a spring which in turn dampens the motion of that actuating apparatus. The dampening of that motion tends to encourage a series of vibrations which are of low intensity, thereby facili¬ tating considerable energy transfer to the filter cake.

Summary of the Invention An apparatus for removing filter cake i a filter pres filter press is disclosed. An apparatus constructed in accordance with theinstant invention is adapted for association with a filter press which includes a plurality of filter plates mounted in essentially parallel and upright fashion upon a frame

assembly. The filter plates are mounted with means for moving the plates along the frame assembly to facilitate the opening, i.e. the separation, of each abutting pair of plates.

The filter "press of the instant invention typically 5 includes a filter cloth or medium which is positioned upon an abutting face of each filter plate, i.e. between each pair of filter plates in a conventional manner. The filter cloth is suspended from a horizontal rod typically mounted above and between each pair of plates. The filter cloth or medium is

10 typically folded over the horizontal rod. Further, the filter cloth is conventionally secured at each of its ends to a respec¬ tive lower portion of the respective abutting filter plates. This arrangement of horizontal rods, together with a filter clot securely positioned at its end sections to abutting adjacent

15. filter plates, results in an essentially inverted "V"-shaped

. cross-sectional configuration or orientation of the filter cloth upon the opening or separation of each adjacent pair of filter ' plates.

The instant invention is directed towards a means and

20 method of impulse- or impact-loading the filter cloth through means of the horizontal rod support, whereby the filter cloth is suddenly drawn taut under tension from a substantially unten- sioned, slackened position whereby the cake or other debris whic are deposited on the surface of the filter cake are forcefully

25 ejected by the whip-like or snapping motion imparted to the fabric of the filter cloth.

An apparatus constructed according to the instant invention generally includes a filter cloth suspension means mounted above the filter press and adapted to suspend the filter 0 cloth in a tensioned orientation, e.g. a substantially inverted

"V"-shaped configuration, upon the opening of the adjacent filte plates housing the filter cloth. The suspension means may also function as a mounting platform for an impulse- or impact-loadin

eans which is adapted to ease and substantially lessen any tension applied to the filter cloth by the horizontal rod by displacing that rod downwardly. The displacement of the rod* downwardly causes the filter cloth to reach a slackened condition. Thereafter, the impact-loading means suddenly applie an impact-tensioning load to that filter cloth through a rapid displacement of the horizontal rod upwardly, thereby bringing th filter cloth to a taut condition. This sudden tensioning of the filter cloth imparts a whip-like or snapping motion to the cloth which results in the displacement of the filter cake from the surface of the filter cloth. The instant invention is not directed toward vibrating the filter cloth. Instead, the displacement of the cake from the filter cloth results from a sudden and violent snapping of the slackened filter cloth as opposed to an oscillating or vibrationally induced motion within • the cloth. -

In a preferred embodiment, the filter cloth suspension means includes generally a pair of suspension arms which are positioned on each of the opposed sides of each respective pair of filter plates. The suspension arms are mounted pivotedly at their proximal end to a first adjacent filter plate and at their distal end to a corresponding positioning on the opposing second adjacent filter plate.

Each suspension arm may include a pivoted juncture positioned proximate the midpoint of the suspension arm whereby the suspension arm adopts an essentially "U"-shaped or "V"-shape configuration. The pivoted juncture permits the suspension arm to open and close as the corresponding adjacent filter plates ar opened and closed. The invention is also adapted for the openin of a plurality of adjacent filter plates and their subjection to a simultaneous filter cake-removing force application.

Positioned on the suspension arms is an impulse- or impact-loading means which may be a resilient elastic member. I

a preferred embodiment, this loading means may be a plurality of spring members, e.g. coil springs, which are positionable betwee two orientations or conditions—a first condition wherein energy which is typically resultant from the spring being compressed under the action of a driven contact plate into a compressed orientation, is stored in the loading means (e.g. springs); and second condition wherein the driven compressive action of the contact plate is released suddenly, permitting the spring member to return to an equilibrium position and thereby effecting a rapid, upward displacement of the horizontal rod and an accom¬ panying whip-like or snapping motion being induced within the filter cloth.

A proximal end of .each spring member is fixedly mounte to the suspension means. The distal end of each spring member i mounted in contact with a first contact plate, which plate is displaceable between the described first, condition wherein the spring is compressed and a second condition wherein the plate does not effect a compressing action upon the spring and in fact may actually not be in contact with the distal end of the spring The first contact plate may include a first connection means which extends from the plate and further may extend throug the interior of a coiled spring. The first connection means may include a horizontally positioned bar which extends essentially parallel to the horizontal rod. The horizontal bar member includes a second connection means adapted to connect with the horizontal rod. The first connection means is fitted with an abutment surface. The first abutment surface is adapted to be contacted and driven by a second contact means which itself is adapted to be moved between two distinct conditions—a first condition in which the contact plate effects a driven downward displacement of the first connection means and thereby effects a downward displacement of the horizontal rod; and a second condi¬ tion wherein the second contact plate is essentially retracted

suddenly from the abutment surface of the first connection means and in effect may actually be withdrawn from contact with the abutment surface of the first connection means. This retraction permits the spring which is compressed under the first condition to expand and direct the horizontal rod suddenly upward, thereby drawing the cloth taut by a tensioning impulse- or impact-loadin of the filter cloth. This sudden displacement of the cloth effects a whip-like or snapping motion within that filter cloth which discharges the cake deposits from the filter cloth. The second contact plate is actuated by a driving actuation means. This actuation means may include pneumatic or hydraulic means adapted to effect the downward displacement or first condition of the second contact plate. A secondary spring means which may be fitted to the second contact plate is adapted to effect a sudden and rapid retraction of the second contact means from the abutment surface upon the release.of the down¬ wardly driving force on the second contact means.

Brief Description of the Drawings FIG. 1 is a side view of a conventional filter press fitted with the filter cake removal apparatus of the instant invention. As shown, the new apparatus is fitted on the top or upper portions of the filter press;

FIG. 2.is a perspective elevational view of the actua¬ tion means of the filter cake removal apparatus of the instant invention. FIG. 2 includes a cut-away view;

FIG. 3 is a side view of the suspension means and attendant impact-loading means of the instant invention showing the filter cloth in an essentially taut, tensioned and impact- loaded condition prior to the discharge of the cake from the filter cloth surface;

FIG. 4 ia a side view of the instant invention similar to that shown in FIG. 3 wherein the filter cloth is shown in a

substantially untensioned or slackened orientation;

FIG. 5 is an elevational perspective view of a portion of a suspension means of the instant invention adapted for sup¬ porting the filter cloth; FIG. 6 is an elevational perspective view of a portion of an alternative suspension means of the instant invention adapted for supporting the filter cloth; and

FIG. 7 is a partial side view of a filter press of the instant invention adapted for simultaneous multiple plate openin and cake removal.

Description of the Illustrated Embodiments As shown in FIG. 1, a conventional filter press includes generally a frame assembly 15 which provides an essen¬ tially channel-like construction for the containment of a series or plurality of filter plates 17. Filter- plates 17 are generall of a rectangular, planar configuration and are oriented in a substantially upright positioning. As shown, the filter plates 17 are positioned parallel one another such that each plate, generally 10, is in an abutting relationship with an adjacent plate, generally 19. The plates 17 are driven along the channel defined by frame assembly 15 under the action of a power-driven head, generally 21. The frame assembly 15 is fitted with means shown generally as separation means 16. Separation means 16 is of a type conventionally known in the art, such as that shown in U.S. Patent No. 4,105,560 (Fismer). Separation means 16 is adapted for separating or opening each pair of plates 17. The invention also contemplates a separation means such as shown in Fismer wherein a multiplicity of pairs of plates 17 may be simul taneously opposed as shown in FIG. 7. As shown, two plates 23, 24 are in an opened position, that is, each plate is substan¬ tially removed from an abutting relationship with one of its adjacent plates, thereby exposing a filter cloth 27 which is

positioned between the abutting faces 29, 31 of the respective plates 23, 24.

Filter cloth 27 is generally rectangular in configura¬ tion and, as shown, includes a proximal end 33 which is substan- tially fixed, or alternately securely fastened, to the lower regions 35 of the plate 23. Similarly, the distal end 37 of the filter cloth or medium 27 is fixedly mounted to the lowermost regions 39 of plate 24.

As shown in FIG. 6, the filter cloth 27 is folded or draped proximate its central portion over a horizontal rod 41 which extends essentially parallel to the planes of abutting faces 29, 31 of the respective plates 23, 24. Horizontal rod 41 is positioned substantially above and between the plates 23, 24. The horizontal rod 41 in suspending the filter cloth imparts a substantially inverted "V"-shaped configuration or orientation t the filter cloth 27. Alternately, as shown in FIG. 5, the filte cloth 27 may include two separate panels 28, 30 which are each draped and secured to a respective horizontal rod 41A and 41B. Horizontal rods 41A, 41B similarly function to suspend the filte cloth in an essentially inverted "V"-shaped cross-sectional configuration.

As shown in FIGS. 1 and 4, the filter cloth 27 is positionable within a variety of configurations. These config¬ urations result essentially from variations in the elevation or orientation of the horizontal rod 41. A displacement or positioning of the horizontal rod 41 at a lower elevation result in the filter cloth 27 being substantially slack and untensioned. As shown specifically in FIG. 1, this slackened condition generally results in the surface of filter cloth 27 adopting an irregular as opposed to a smooth linear cross-section. The irregularity is in part resultant from the deposits of solids or cake materials 42 which are positioned on the interior facing surfaces 43, 45 of the filter cloth 27. As the cloth 27 is

slackened, cracks or fissures may result in the cake deposits, thereby encouraging a displacement of some of the cake from the surface of filter cloth 27.

The horizontal rod 41 is held in position by the actio of connection means 47. As shown in FIG. 2, connection means.47 may comprise a substantially cable-like member 48 which is posi¬ tioned around the circumference of the horizontal rod member 41 and extends upwardly to be secured about a bar member 49 within channel 50 defined within that bar member 49. Bar member 49 extends essentially parallel to horizontal rod 41 substantially along its complete length. Alternately, as shown in FIG. 4, the rod 41 may be connected to a connection means 51 which includes an essentially shaft-like member 52 which extends downwardly and is fixedly mounted on the horizontal rod 41. In both constructions, either the horizontal bar 49 or the connection means 51 is fitted to an upwardly extending shaft 53. Shaft 53 extends upwardly and is fitted proximate its end 5 to a first contact plate 57. As shown, contact plate 57 may be an essentially planar member having a sufficient contact surface to abut against a spring-like or elastic member 58. Spring-like member 58 may be a coil spring.

Contact plate 57 is securely held from displacement toward the end 55 of shaft 53 by a restraining means 59. This restraining means 59 may be an interiorly threaded nut 61 which is fitted about a threaded portion 62 of the shaft 53. Spring 5 is fitted at its distal end 63 to a platform 73. Platform 73 is mounted on a rod 75 which forms the pivot 77 of suspension arms 65. Rod 75 extends between the pairs of suspension arms 65 whic are located at opposing sides of the frame assembly 15 (not shown). As shown, suspension arms 65 may each include a pair of auxiliary arm members 67 which are pivotedly mounted at point 69 so as to be rotatable about pivot point 69. The distal end 71 o each arm 67 is pivotedly mounted on the opposing upper structura

region of each pair of adjacent filter plates 23, 24, thereby defining an essentially inverted "V-shaped configuration which is expandable about pivot point 69; i.e., upon filter plates, generally 81 and 83, being displaced in the directions indicated generally by 85, the ends 71 of auxiliary arms 67 are likewise displaced along directions 85. Upon the filter plates 23, 24 being brought into abutment, the ends 71 of arms 67 are likewise brought into close proximity.

Positioned proximate the horizontal bar 49 is a second contact plate 90. In FIG. 2, this contact plate 90 is shown as substantially rectangular planar member. Contact plate 90 abuts against bar 49 on an abutment surface, generally 92. Contact plate 90 is mounted on a threaded shaft 94 which extends from a pneumatic or hydraulic piston, generally 96. As shown, piston 9 is mounted on a movable carriage 99 which also carries separatio means 16. The threaded shaft 94 is dimensioned to be slidably received within an aperture 98 within the contact plate 90. A portion of shaft 94 extends through an aperture 98 in contact plate 90 and is fitted with a retaining means 99, e.g. a threade bolt 100, which retains the contact plate 90 against any upward displacement.

An auxiliary spring 102 is mounted in abutment against the side 104 of plate 90 opposite the retaining means 99. The distal end 106 of spring 102 is mounted in abutment against piston 96 such that upon the driven displacement of contact plat 90 downwardly, i.e. in the direction indicated by arrow 108, the spring 102 is_ compressed, thereby storing energy. Upon the piston 96 removing any downwardly directed force application to the contact plate 90, e.g. in the case of a pneumatic piston by releasing air pressure through outlet 110, the spring 102 force¬ fully directs the contact plate 90 upwardly, thereby releasing any downwardly directed force application upon bar 49.

As shown in FIG. 7, the construction of the instant

invention may facilitate a multiple filter plate processing wherein a plurality of adjacent filter plate pairs, as opposed t a single pair of such plates, are opened by the separation means 16. Thereafter, the second contact plate 90 which extends -sufficiently so as to contact the abutment surface 92 of each respective pair of plates 17 is driven downwardly by the simul¬ taneous action of two pistons 96 which are individually positioned on opposing ends of the second contact plate 90. In operation, a filter press having a plurality of upright, abutting filter plates 23, 24 is injected with solids- bearing liquid. The liquid, in passing through filter cloths 27 arranged between each pair of abutting plates 23, 24 deposits th solids suspended therein on the filter cloths 27. Upon draining the liquid, each pair of adjoining plates 23, 24 is systemati- cally separated, i.e. opened. Upon the opening of each pair of - plates 23-, 24, the respective filter cloth 27 is oriented in a substantially inverted "V-shaped cross-sectional configuration due to the support action of horizontal rod 41 positioned above and between the adjacent plates 23, 24. The rod 41 is then forced downwardly by the action of driven second contact plate 90 which is driven by a pneumatic, hydraulic or other power source 96. Upon being forced downwardly, the rod 41 permits the filter cloth 27 to reach a slackened, substantially untensioned orientation. The downward displacement of rod 41 is resisted by a plurality of springs 58 which are connected to the horizontal rod 41 by a linkage assembly or first connection means. Upon the rod 41 reaching a predetermined elevation or position, the driving force on the second contact plate 90 is suddenly released. An auxiliary spring 102 mounted on the second contact plate 90 operates to forcefully retract plate 90 from its association with rod 41.

At this juncture, the plurality of springs 58 operate suddenly and rapidly to displace the rod 41 upwardly, resulting

in the rod 41 impacting against the filter cloth 27 and bringing that cloth to a taut and tensioned orientation. The force of th rod 41 against the cloth 27 results in a whip-like motion within the fabric of the cloth 27 which serves to knock the cake deposits 42 from the surface of the cloth. Further, the force o gravity operates to cause the cake 42 to fall downwardly away from the surface of filter cloth 27.

It is to be understood that the embodiments herein described are merely illustrative of the principals of the invention. Reference herein to the details of the illustrated embodiments is not intended to limit the scope of the claims which themselves recite those features regarded as essential to the invention.