US2508976A - Filter device - Google Patents

Description

May23,195o R. @.TESSMERSB 2,508,976

FILTER DEVICE Filed Ilay 28, 1948 @QQ/mond G. Tess/e5 5ft,

ATTORN EYS.

meme M, 23, 195o FILTER DEVICE Raymond G. Tessiner, Sr., Tonawanda, N. Y.. as-

signor to Arnold Jacobowita, Buffalo, N. Y.

Application May 28, 1948, Serial No. 29,778

1 Claim.

This invention relates to industrial liquid illters, and more particularly to improvements in so-called plate of "pulp type illters comprising series oi' superposed plates or pulp cells each of which includes centrally thereof a drainage device having an open center for leading oil the liquid filtering through the encasing matte of "pulp or other material functoning as the lterlng medium.

The drainage members of such "pulp cells have been previously formed such as for example from wire screen stock fashioned into superposed paired disks each mounted upon grooved hub devices so as to allow passage of iiuid between the screens and their hubs into the central discharge outlet of the unit. Such arrangements however have proven to be disadvantageous because of the tendencies of the screen disks to press into closely intermeshed relation as the filtering pulp is 1my pressed and caked thereon from opposite sides by the cell packer press in which they are pressed or formed prior to loading of the cell into the illter apparatus cylinder, thereby affording inadequate fluid ow passages therebetween; and also because of the tendencies of such screen disks to ex at the outer edges of their hubs under'the pressures exerted by the pressing` operations thereon, which results in early structural failures of the screen disks at their junctions with the hubs.

It is an object of the present invention to provide an improved form of plate cell drainage device which is adapted to give improved drainage into the central outlet. while at the same time being substantially rigid structurally and free from thickness discontinuities such as exist when hub devices or spacers or the like are employed, and'such'as would contribute to iiexure failures of the parts incidental to packing of the pulp cells.

Another object of the invention is to provide a drainage device for use ln a pu1p" type filter plate'or cell, which will consistently provide adequate drainage space uniformly throughout the extent of the cell.

Another object of the invention is to provide for the purpose referred to an improved drainage unit which is free from entangling wire ends or other irregularities such as would tend to accumulate pulp fibers or filtered solids deposits at positions which are inaccessible for cleaning.

Another object of the invention is to provide an. improved drainage unit for the purpose aforesaid which is adapted to be relatively inexpensively fabricated of readily available stock ma- 2 terial; each of said units comprising a pair oi identical members thereby providingr interchangeability of parts for simpliiled assembly and servicing operations.

In the drawing:

Fig. 1 is an elevation, with parts broken away to show the interior, of a typical "pulp" filter of the type to which the present invention relates:

Fig. 2 is an exploded perspective view of the elements comprising a single pulp plate or cell embodying a. drainage unit of the present invention;

Fig. 3 is a fragmentary radial section, on an enlarged scale, through a cell drainage unit of the invention; and

Fig. 4 is a fragmentary radial section` on a smaller scale, of the pack of ltering cells and cell separators within the machine.

The invention is illustrated in the drawing. by wav of one typical application, to a pulp" illtering machine which comprises generally a cylindrical tank I0 having a top cover I2 arranged to be pressed into tank sealing position by a hand wheel and screw unit I4. The interior of the tank Il! accommodates a plurality of ltering plates or cells designated generally at I5 which are disk-shaped so as to readily slip-lit into the tank l0 while leaving a marginal space yi6 between the outer edges of the plates and the wall of the tank for liquid entrance purposes.

As best illustrated in Figs. 2-4. each plate or cell I5 comprises a drainage unit of the present invention which is designated generally at i8. Each drainage member is centrally apertured as indicated at 20 and is circular in plan view and of an outer diameter which is less than the outside diameter of the corresponding cell. Each cell further consists of a matte of fibrous pulp or other suitable filtering medium as is indicated at 22; the pulp 22 having been caked upon the drainage unit I8 at opposite sides thereof and around the outer periphery thereof by previous packing of the pulp in layers against opposite sides of the drainage member in a typical pulp press or the like, as is well known in the art. As is customary in connection with the packing of lter plates upon other forms of drainage devices, the pulp 22 is prevented from blocking the central aperture 2li of the drainage unit, and is formed with a circular bore 24 in alignment with the bore 20 through the drainage member, as by means of suitably shaped die plates in the cell press machine. l

Adjacent filter plates within the cylinder i0 are separated by iiuid passage members 26 which are illustrated herein to be of conventional form such as may be fabricated of coarse wire screen stock diametrically dimensioned so as to slip-fit into the cylinder I; thereby separating adjacent ltering plates while providing free fluid passageways therebetween in communication with the fluid passageway II surrounding the stack of iiitering plates. The separator screens 26 are provided with vertically bored central hubs 28: and thus when the filtering plates I0 and the separator screens 28 are stacked in alternately superposed relation within the cylinder I0 the bored central portions thereof mutually align so as to form an open channel vertically through the center of the mtering cell stack. As shown at 29 (Figs. 2-4) the top and bottom surfaces of the pulp plates 22 are formed with counterbores complementing the hubs 28 of the separator screens, so that when the filtering and separating elements are stacked within the cylinder the central edge portions of the pulp cells function as gaskets between the separator hubs, thereby providing a fluid-sealed central opening vertically throughout the stacked components, whereby the assembled filter is adapted to successfully withstand excessive pressures during filtering operations without leakage of unfiltered liquid into the nitrate. The counterbored portions 29 of the pulp cells may be convenientk provided by employing complementary shaped press plates above and below the pulp material while it is being compacted in the press into the form of the filtering plates illustrated herein.

As indicated in Fig. 1 at 30, a filtered liquid outlet conduit 32 is arranged in the base of the tank I0 to register with the central opening through the stack of' filtering cells; and a fiuid inlet conduit 34 is arranged to deliver liquid to be filtered into the cylinder I0 adjacent the top end thereof. A second fluid inlet conduit 36 and control valve 38 is shown for the purpose of permitting selective use of inlet conduits leading into the top and the bottom of the cylinder l0. respectively.

Thus, it will be appreciated that upon filling of the tank I0 with alternately stacked cell and separator elements, the liquid to be filtered may be let into the tank through the conduits 34-36 whereupon it will circulate about the filtering cells and therebetween through the passageways afforded by the coarse screens 20. However, the screen hubs 20 block the passage of unfiltered liquid into the central opening and therefore all of' the liquid is forced to pass through the filtering pulp material 22 in order to gain access to the drainage units I0 which are disposed interiorly of the filtering cells.

As illustrated in Figs. 2-3-4, each drainage unit of the invention comprises a pair of diskshaped plates or leaves lll-l0 which may be formed for example of sheet metal stock minutely perforated as indicated at 42 (Fig. 3) and embossed as indicated at M. 'Ihe embossing pattern may be of any configuration desired, but characteristically embodies some pattern providing an alternately raised and depressed surface contour such as for example a nodular surface at one side of each sheet and a multiple cupped surface at the opposite side thereof. The sheets 40-40 are then disposed in face-to-face relation, that is with the raised surfaces thereof meeting so as to provide the open uid passageways therebetween as indicated at 45 (Fig. 3). Because of the oppositely raised and depressed surface formations of the disks l-ll, the fluid passageways 4l therebetween are uninterrupted irrespective of the relative orientations of the disks of each unit; there being at all times a plurality of passageways around each point of dome-to-dome contact between the disk units. Thus, it will be understood that the liquid entering through the conduit 3l will be forced to find its way through the filtering pulp material of the cells l5 and thence through the minute perforations I2 and into the fluid channels I5 between the disks 40-40, and thence into the Open hub portion 20 of the drainage units for passage downwardly through the open center of the stack of nltering cells, and then finally into the outlet conduit I2.

Thus, it will be appreciated that the drainage units of the invention are adapted to be inexpensively manufactured from readily available sheet stock or other fabrications formed of metal or any other suitable material perforated and embossed, and are adapted to function at all times to provide consistently free passage of filtered liquid therethrough without clogging and/or entangllng of pulp fibers or other undesirable solids; and that the packingpressures of the caking press will not cause the drainage disks to flex in such manner as would cause them to break.

What is claimed is:

In a filtering plate comprising a body of liquid filtering medium, a filtrate drainage unit disposed interiorly of said body and extending to an edge thereof for delivery of filtrate therefrom, said drainage unit comprising a pair of sheet members disposed in superimposed relation forming a multitude of sinuous fluid passageways therebetween, each of said sheet members being centrally apertured and embossed to provide a multitude of spaced, generally cup-shaped, rounded domes in close proximity on one side thereof alternate with depressed surface formations of somewhat smaller area and extending substantially continuously throughout each of said members to the edges thereof, each of said domes and said depressed formations being minutely perforated for conducting liquid feeding through said medium, said sheet members of the drainage unit being arranged so that the domes of each are in abutting contiguity whereby to provide said fluid passageways therearound for delivering filtrate to an edge of said drainage unit.

RAYMOND G. TESSMER, SR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 612,105 Hendrick Oct. 11, 1898 1,636,177 Gage July 19, 1927 1.716.786 Lipscomb June 11, 1929 1,790,036 Wiltse Jan. 29, 1931 1,965,999 Beatty July 10, 1934 2,392,354 Alsop Jan. 8, 1946 2,435,115 Alsop Jan. 27, 1948 FOREIGN PATENTS Number Country Date 13,466 Great Britain of 1899 358,526 Great Britain Oct. 5, 1931 672,365 France Mar. 30, 1929 98,389 Germany July 25, 1898 OTHER REFERENCES Websters New International Dictionary, 2d edition, 1940. pages 645, 768 and 1388.

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