Filter

Dec. 11, 1945.

2,390,628

P. VAN WINKLE

FILTER

Filed July 28, 1943

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ATTORNEY

Patented Dec. 11, 1945

2,390,628

UNITED STATES PATENT OFFICE

2,390,628

FILTER

Paul Van Winkle, Scarsdale, N. Y., assignor, by mesne assignments, to George B. Finnegan, Jr., New York, N. Y., as trustee

Application July 28,1943, Serial No. 496,466

Claims. (Cl. 210—188)

The invention relates to improvements in filter press parts and more particularly tp a new and useful filter press plate and the associated frame therefor.

Objects and advantages of the invention, will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serves to explain the principles of the invention.

Of the drawing:

Fig. 1 is a front elevation of a filter press plate embodying the invention, showing a filter medium in position thereagainst with parts thereof broken away to show the construction of the plate;

Fig. 2 is a vertical section on line 2—2 of Fig. 1; and

Fig. 3 is a horizontal section on line 3—3 of Fig. 1; showing a plurality of plates and frames in assembled relation in a filter press.

Objects of the invention are to provide an improved filter plate in which the drainage grid is removable from the surrounding and supporting frame or “window,” said drainage grid thereby being capable of replacement upon breakage of any individual part thereof without requiring the replacement of the entire drainage grid or of the frame which supports it. Moreover, by virtue of said arrangement and construction, the drainage grid is preferably made up of a plurality of separated and individually removable elements which are sufficiently loosely mounted in the supporting frame so as to permit a substantial expansion and contraction of the drainage members without warping or buckling thereof or of any parts of the press under changes of temperature and varying moisture conditions and other influences which normally cause warping, buckling or undesirable expansion movements.

Another object of the invention is to provide with such movable and expansible grid construe^ tion, a bordering frame or supporting window for the grid which will be of great strength, integrity and impermeability to leakage under high pressures, temperatures, and other physical and chemical influences. With this end in view the invention provides a grid-supporting frame or window which is preferably integral in construction and material, preferably being formed of solid “Bakelite” or like strong and chemically 6 inert material so that possibility of leakage through joints therein is avoided. Another feature of the invention resides in the arrangement of the composite drainage grid and its supporting frame and enveloping window or border with respect to the intervening frames which assist in supporting the drainage grids within the interplate filtration chambers when the parts of the filter are assembled and closed together under pressure. By virtue of the invention, the conⁱ⁵ struction, arrangement and relation of Jhe plates and the intervening frames are such that when the press is closed and subjected to closing pressures, said pressures are absorbed substantially entirely by the solid bordering portions of the ²⁰ filter plates, and frames, thereby relieving the relatively delicate and loosely mounted parts comprising the grids of the plates from such pressures. By this arrangement the drainage grid is enabled to withstand any reasonable hydro²⁵ static pressure incurred during the filtration cycle without subjecting the parts thereof to any substantial mechanical stress. In accordance with another feature of the invention all parts of the 30 filter press plates and frames may be and preferably are made- of “Bakelite” or other similar strong, rigid chemically inert material, preferably laminated with cloth, paper or other fibrous material, which feature has been found very desirable 35 and useful in the filtration of many acids, bases and other penetrating reagents destructive to wood, metal and other materials.

Another object of the invention is to provide means whereby ready removal of the drainage 40 grid members from the surrounding window frame can be effected without requiring any breach in or mechanical disassembly of any part of said surrounding integral frame. Tn accordance with this feature of the invention the grooved drainage 45 grid members are lightly held in place by a novel and special form of dowel construction whereby the grid members may be readily assembled and disassembled from the surrounding frame. Another object of the invention is to provide a con50 struction wherein all of the parts of the composite filter plate are cut from a single integral piece of material, such as laminated “Bakelite,” the cutting-out operations being such that spaces for the purpose of permitting expansion between ⁵⁵ the drainage grid members and the frame and

2,880,628 between each other are automatically provided by said cutting-out operations.

Another object of the invention is to provide a form of frame for a plate and frame filter press which is designed and adapted to cooperate with the novel form of filter plate hereinabove described whereby through said cooperation leakage between plates and frames Is prevented and the stress exerted during closure and operation of the press is borne by the solid parts of the plate and by the frames so that the drainage grid portions of said plates are relieved from said subjection to such stresses.

Other novel features of the invention will be pointed out hereafter or will be obvious from the disclosure and context. It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention, but are not restrictive thereof.

Referring now in detail to the present preferred embodiment of the invention illustrated by way of example in the accompanying drawing, it will be clear that the invention is designed to accommodate itself to substantially any standard filter press construction so far as the supporting framework and the assembling and tightening devices are concerned. The plates which constitute the major working units of the mechanism in forming the assembled press comprising an external rectangular frame ί of “Bakelite” or similar plastic, preferably laminated with kraft paper, cloth or the like, or of other material with equivalent chemical and mechanical properties, said frame being preferably integral or solid throughout its rectangular extent so that, in accordance with the invention, all cracks, seams and leakage openings therethrough are avoided.

Suitable inlet holes or eyes 2 are formed in the upper corner or comers of the plate frames i in known manner for the admission of slurry or liquid to be filtered. Either or both of the lower corners of frame i are similarly apertured at 3 to provide drainage channels or conduits for the discharge of filtrate, communication thereto from the lower ends of the vertical drainage channels in the drainage grids being provided as hereinafter described.

The drainage grid portion of the plate is formed by saw-cutting a generally rectangular'window or opening in the solid rectangular plate from which the frame I is formed. Said opening is cut along the top line 5, the sides lines 6 and 7 and the bottom line 8, it being noted that a curved boss or enlarged portion 9 is formed at each of the corners to reinforce the surrounding frame adjacent the eyes 2 and 3. As shown, the saw-cuts 5, 6, 7 and 8 are of a width sufficient to provide a gap or clearance around the entire cut-out edge, said gap being preferably Vb” wide, thereby to provide room for expansion of the internal drainage grid under changing temperatures and moisture conditions.

The drainage grid comprising the portion of the original block or plate of material outlined within the saw-cut 5-8 may constitute a single solid piece of the material, but preferably, in accordance with the invention, same is formed of a plurality of panels or strips. As shown, there are four such panels numbered 10, Ii, 12 and 13, respectively. As will be noted from the drawing, each of said panels is separated from the adjacent one by a cut or gap 14, formed by the act of sawing or dividing up the internal rectangle into the several strips or panels. Said inter-

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nal gaps 14 thereby provide additional spaces for lateral expansion of the grid forming members.

Each of the grid-forming panels 10-13 is, as shown, provided with vertical lands 20 and δ grooves 2i which preferably run from near the top to near the bottom of the panel on each vertical face thereof. As shown, said grooves are of uniform depth throughout their length, but the invention is not limited with respect to the 10 formation of the drainage surface of the drainage grid or panels and same may be of any known or suitable construction. That is, it may be corrugated, pyramided, knobbed or formed with any desired arrangement of cross-channels or 13 manifolds.

Any suitable arrangement for drainage of the plates into the bottom conduits 3 may be provided. As shown, one or more horizontal crosschannels 25 may be provided near the bottom of 20 the grid panels and same may communicate with the conduits 3 by means of conduits 26 which are angled in from the surface of the crosschannel 25 to the center of the frame i from each side of the plate. This construction permits 25 cleaning of the grid without removing the plate from the press. In the same manner horizontal cross-channels 28 may be provided near the top of the grid for introduction of wash water which may be directed thereinto from the upper chan30 nels 2 by angled conduits 29. It will be understood, however, that the invention is not limited to the type of filtrate discharge channels and wash water channels and conduits, as internal manifold construction therefor may be provided 35 or any other known and suitable type of design for these purposes.

The invention provides novel means for loosely holding the several drainage grid panels 10-13 in position in the solid frame I so that same may be 40 assembled and disassembled readily. As embodied, the upper ends of each of the several panels are socketed at a plurality of points 30 to receive lower ends of loosely seated dowels 31, the upper ends of said dowels projecting into ⁴³ suitable recesses or sockets formed in the overhead portion of the solid frame i. A similar construction is provided at the lower ends of the panels, said ends being provided with sockets which sockets, however, are. twice the depth ⁵⁰ of the sockets 30 above. Dowels 33 are thus adapted to seat fully into the sockets 32 and be flush with the ends thereof when so seated. Sockets 34 are formed in the bottom portion of the solid frame 3, said sockets being of· ⁵⁵ normal depth, i. e. one-half the length of the dowels 33. By means of this construction it is possible to place the panels in position so that the upper dowels 31 are seated in the upper sockets 30. By holding the plate 60 and panels upside down the upper dowels are thus located and seated while the bottom dowels settle fully into the sockets 32. By then turning the plate into its normal upright position, the bottom dowels 33 drop into the bottom sockets ⁶³ 34 thus locking the grid in place. This construction provides means for readily inserting and removing the grid panels with respect to the frame I and also allows for vertical expansion of each panel. Suitable washers 35 are prefer70 ably placed around each of the dowels above and below so as to maintain the desired spacing at the top and bottom of the panel. It will be understood that the diameter of the dowels is slightly less than that of the sockets surround75 ing them so that sufficient play exists to permit

3 a hollow rectangular spacing frame mounted and adapted to be pressed into close engagement with said filter medium, the border portion of said spacing frame being wider than that of said firstmentioned plate frame so as to overlap the junction between said plate frame and the drainage grid removably mounted therewithin, and means for pressing said spacing frame tightly against the plate frame to seal the press for filtration.

2. In a filter press, in combination, a filterpress plate having an outer frame formed of an integral piece of material and a drainage grid removably mounted within said frame, a filter medium in the form of a sheet overlying the sur15 face of said outer frame and drainage grid, and a hollow rectangular spacing frame mounted and adapted to be pressed into close engagement with said filter medium, the border portion of said spacing frame being wider than that of said first20 mentioned plate frame so as to overlap the junction between said plate frame and the drainage grid removably mounted therewithin, and means for pressing said spacing frame tightly against the plate frame to seal the press for filtration.

3. In a filter press, in combination, a filterpress plate having a rectangular outer frame, said frame having a leak-proof surface formed of a continuous integral piece of material, and a drainage grid composed of a plurality of separate ver30 tically disposed channel forming members, said channels running from the top to the bottom of the grid, an inlet in the frame near the top thereof to supply matter to be filtered and an outlet near the bottom of the frame to discharge liquid 35 which travels to the bottom of said channel, a filter medium in the form of a sheet overlying the surface of said outer frame and drainage grid, and a hollow rectangular spacing frame mounted and adapted to be pressed into close engagement ₄₀ with said filter medium, the border portion of said spacing frame being wider than that of said firstmentioned plate frame so as to overlap the junction between said plate frame and the drainage grid removably mounted therewithin, and means ₄₅ for pressing said spacing frame tightly against the plate frame to seal the press for filtration.

4. In a filter press in combination a plurality of rectangular frames of integral solid material disposed in tandem, each of said frames having an interiorly-disposed drainage grid composed of a ^5U plurality of removable members, means for supporting filter media between said frames against the faces of the drainage grids, open rectangular spacing frames of Integral solid material mounted between said plate forming frames to form filtra⁵³ tion chambers, said spacing frames and plate frames being designed to receive and transmit together the entire mechanical stress of closing the Units of the press together while said drainage grids are substantially free from said stress, said ⁶⁰ spacing frames being of substantially the same external dimensions as said plate frames and of less internal dimensions than said plate frames. PAUL VAN WINKLE.

2,390,( the desired lateral expansion of the panels with respect to each other and the frame I without undue stress on the dowels.

It will be understood that other means than the dowels may be provided for mounting and 5 holding the grid panels removably within the frame 1, such for example as lateral rods running through the grid panels and into the bearing frame I, the panels being preferably loosely slidable on such rods. ' 10

The invention also provides frames for spacing the filter plates so as to form the usual filtration chambers therebetween. As shown, said frames are composed of solid, integral rectangular members shaped essentially like the plate holding frames I. However, the open internal rectangle or “windows” of said frames 40 are slightly smaller than the corresponding open portions of the rectangular plate frames I, thereby providing that the solid portions of the frames 40 overlap the gaps 5, 6, 1 and 8 between the frame t and the grid forming panels therewithin. As shown in Fig. 2, for example, the upper edges of the frame 40 extend substantially below the gap 5 and there is a similar overlapping at the bottom and along the side edges of said frames 40. This construction insures that upon closing of the press under pressure the full stress of that pressure will be borne by the frames 40 and the abutting plate frames I, the “floating” drainage grids being relatively free from such stress but held securely in place by the overlapping of the frames 40.

As shown, any suitable form of filter medium 45 is disposed between the adjacent surfaces of the frames I and 40 so as to lie against the lands of the drainage grids and also to serve as sealing gaskets between the abutting surfaces of the frames I and 40.

The words “grid” and “drainage grid” as used herein are intended to mean a filter cloth-supporting element that has drainage channels therein. The element may be either simple or complex in that it may be comprised of a single panel or made up of a plurality of panels or sections such as 10, 11, 12 and 13, characterized by having alternating cloth-supporting lands and drainage channels. The drainage grid and its holding frame may be either rectangular or any other shape that circumstances may dictate as being appropriate for the filter press frame or the drainage grid thereof.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.