FI57699C - FILTERHYLSA FOER TRYCKFILTER - Google Patents

Description

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JHa μ (11) utlAcgnincsskiuft 57699 C (45) P = ^ r.tti rySr.r.clty 10! 0 1C 3 9 (51) K ».nu3yinta3 b 01 D 29/14 FINLAND — FINLAND pi) 1980/71 ( 22) Hakwntopilvt - AnaBknlngidig 12.07.71 '' (23) Alkupllvt — Glltlglwttdag 12.07.71 (41) Tullut JulkMtcl - BllvIt offuntllg 01 72 exam, and registry administrators („} NlhtMtolpiBen | t

Patent · och ref isterstyreiten 'Amökan uttagd och utUkrHton pubifcund 30.06.80 _ (32) (33) (31) ttuolkuui — Begird priority 13.07.70 USA (US) 5 ^ 216 _ (71) Dorr-Oliver Incorporated, 77 Havemeyer Lane , Stamford, Connecticut Ο6901 +, USA (72) Harry Victor Miles II, Westport, Connecticut, USA (7M Berggren Oy Ab (5 * 0 Filter sleeve for pressure filter - Filterhylsa för tryckfilter

The present invention relates to a filter sleeve for a pressure filter, comprising a horizontal plate with holes for receiving tubular filter elements comprising a liquid-permeable rigid tube and a filter sleeve formed of a resilient filter fabric so formed that the sleeve is radially expandable, the sleeve being radially expandable, and is provided at its upper end with a radially projecting annular flange for clamping between the horizontal plate and a planar rigid plate portion parallel thereto to hold the sleeve and provide a seal, the flange being in the form of a thickening obtained by wrapping the filter cloth around the ring.

In such a pressure filter, the upwardly open ends of the tubular filter elements are attached to an end plate which divides the container into a lower compartment for cellulose pulp, slurry or suspension to be filtered under pressure and an upper compartment to receive a liquid filter passing through the end plate and filter.

57699 More particularly, this invention relates to improvements in the tubular filter members themselves. One goal is to provide a leak-free connection between the end plate and the filter parts. Another object is to provide a simple and inexpensive filter hose suitable for providing said leak-free connection.

The problem below and the objects of the present invention will be more readily understood by reference to U.S. Patent No. 3,356,215, which includes and describes a filter thickening unit disclosed herein to illustrate the practice of the present invention. Such a filter unit comprises a plurality of parallel pressurized filtration zones, each zone containing a group of said dependent filter parts. These zones can function in filtration so that the filter sections of one zone are subjected to countercurrent washing at a time, while the filter sections of the other zones continue their pressure filtration. Since filtration and countercurrent washing thus take place simultaneously in this filter unit, the countercurrent liquid must, of course, be fed to the filtration zones at a higher pressure than the filtration pressure. During the countercurrent washing, the layer of sludge solids accumulated on the respective filter parts comes off or is moved and settles to the bottom of the tank, from where the accumulated, thickened substance can be removed from time to time.

In said U.S. patent, the porous rigid filter member tube has a flange at the top thereof. The upper end of the filter hose surrounding the tube is attached to a flange portion of flexible rubber material, the circumference of the neck portion of which is attached by knitting to the filter fabric of the filter hose. When this combined filter part is in place, both the rigid flange of the porous tube and the flexible flange or seal are closed or pressed between the upper surface of the end plate and the sector-shaped mounting plate, all filter elements remain in place in communication with the sector-shaped filtrate receiving chamber. - This previous installation and fixing of the filter element caused a leak. This resulted in turbidity of the filtered liquid due to compression set or accidental rupture in the rubber seal that partially detached the seal from the filter hose material.

Further, a dependent tubular filter element is known from U.S. Pat. No. 2,826,308, which is quite similar in appearance to that of the present invention. However, according to the patent 57699, the annular element is made of a flexible thread-like material sewn inside a double fabric. This is thus a separate made ring which is then in turn sewn around the open end of the filter bag. Although this known element is suitable for use in the applications described in the patent, it is of the sealing flange type and tends to leak under pressure.

According to the present invention, the sealing effect is provided by an annular structure comprising a shape-retaining rigid annular core which reliably and effectively seals against the filter pressure acting in the filter container. The sealing effect is provided by a rigid annular thickening which surrounds the filter cloth and seals upwards against the pipe flange and downwards against the rigid plate part. The invention thus differs from the said patent both in structure and idea.

The main features of the invention appear from the appended claim 1.

In a practical implementation, the filter fabric material is used to make the filter sleeve or hose in such a way that the fabric wires run helically with respect to the longitudinal axis of the sleeve, thus making the sleeve expandable, allowing the ring to be pushed into the sleeve even though the ring diameter is much larger than the sleeve.

The inserted ring is located in a plane transverse to the axis of the hose, forming an annular, outwardly directed bulge in the transversely extending filter tube. The non-expandable free top of the filter material is pivoted inwardly through the ring and attached to the surrounding portion adjacent the filter hose from below the ring. The non-compressible ring, thus surrounded by a transversely stretched filter body, forms an outwardly projecting thickening which, when tightly compressed, prevents leakage and tearing.

The clear special features are in the manufacture of a simple and inexpensive filter hose in which the filter fabric of the hose is expandable, and in the method of manufacturing such a hose.

Because the present invention may be practiced in many ways without departing from the spirit or essential characteristics thereof, this embodiment is illustrative but not restrictive. The scope of the present invention is better limited by the appended claims than the description thereof, and all implementations which have the content of the claims and which - are in the range of claims, are therefore intended to fall within the scope of those claims.

Figure 1 is a vertical cross-section of a filter thickening unit according to an embodiment of the invention, provided with a rotating valve tube for countercurrent washing of the filter elements.

Figure 2 is an enlarged view of the upper end of the filter unit, showing more clearly the main components of the unit.

Figure 3 is a cross-sectional view taken along line 3-3 of Figure 2 showing the rotating valve tube and associated flow passages.

Figure 4 is a partial sectional view taken along line 4-4 of Figure 3, further showing the operation of the rotating valve tube.

Figure 5 is a detailed cross-section of the valve tube taken along line 5-5 of Figure 4.

Fig. 6 is a cross-sectional view taken along line 6-6 of Fig. 2 showing the filter unit in a folder radially divided into compartments to form sector-shaped filtering receiving chambers. "

Figure 7 is a partial cross-sectional view taken along line 7-7 of Figure 2 showing the placement of the tubular filter elements in the support end plate.

Figure 8 is a much enlarged, detailed vertical section of a tubular filter element fixed in place, characterized by a specially made thickening at the end of the filter hose.

5,57699

Figure 9 shows an unfinished filter hose characterized by both transverse and longitudinally stretchable filter fabric due to the helical direction of its wires.

Figure 10 shows a mere strip of filter material from which the filter hose of Figure 9 is made.

Figure 11 shows a method of making a strip of filter cloth material of Figure 10 alone.

Figures 12, 13 and 14 illustrate the different steps in making the thickening at the end of the filter hose.

In the embodiment shown in Figure 1, the filter thickening device comprises three main parts A, E, C.

Part (A) of the device includes a cylindrical tank 10 supported by legs 11. An adjustable speed, motorized mixing apparatus 12 is mounted on the bottom of the tank to keep the highly thickened slurry layer S in a flowing state to remove it through a control valve 12a located at the outlet 12b. The side passage 13 as well as the various branch connections 13a are located in the tank. A supply port 14 with a valve 14a for supplying a suspension of solids to be thickened under pressure is located close to the upper end and opens into a supply manifold 14b which may extend around the inner surface of the tank and outlets 14c are located along this tube.

The upper end of the container itself is closed by a plate 15 to which the upper ends of a plurality of suspended tubular filter parts 16 are releasably attached, on the surface of which a layer of suspension solids can form, while the filtered liquid passes upwards through the plate. The closed lower ends of the filter elements terminate at a distance D from what is reported to be the maximum possible height L of the settled thickened sludge layer, this distance being sufficient for the solids, i.e. the decomposed layer, to fall on or into the sludge layer when detached from the filter elements *

The device part CB) comprises a hollow lid or a convex lid part 17 which is mounted on the plate 15 and attached to it and to the upper end of the tank by quick-release screw clamps 18. This lid part 17 has internal radial partitions 19 delimiting with the plate 15 a group of sector-shaped filter receiving chambers (see Figure 6) located around the vertical axis of the tank. The narrow inner ends of these receiving chambers are delimited by a 6 57699 cylindrical vertical wall or tubular partition 21 which itself delimits the central chamber 22 (see Figures 2 & 6). The lid part 15 at the top of the tank with a plate 15 between it is tightly held together by screw clamps 18. Assembly and parts the ratio is such that the bottom edges of the radial partitions in the cover part fit tightly on the plate 15.

A vertical mounting bolt 23 passes through each filtering receiving chamber 20 to further seal the bottom edges of the lid and partitions to the plate 15. Each chamber 20 further has a branch connection 24 with a shut-off valve 25 through which a sample of each chamber filtered liquid can be sampled in the corresponding group which supplies the liquid to the receiving chamber 20 to be examined. *

The apex of the convex and partitioned lid portion 17 is formed as a central, horizontal, flat portion 26 provided with openings 27, one for each chamber 20. These openings 27 are arranged circumferentially around the vertical axis of the container (see also Figure 3) and form a connection between each chamber 20 and said filter collecting and countercurrent washing part (C) placed on the lid part 17. This cover part further has outer lugs 28 by means of which the entire superstructure comprising parts (B) and (C) can be easily lifted off the end plate after removal of the screw clamps 18 for inspection of the filter elements. The installation of the better filter elements themselves and their special construction are described in more detail below.

In part (C), a housing structure 29 for collecting filtered liquid from the chambers 20 forms a filter collecting chamber 29a, and a cylindrical body portion 30 having a filter outlet connection 30a and a cover plate 31 * shown therein is shown here. 32 against wear is shown herein as part of part (C) at the bottom of this housing structure. This plate is placed between the bottom surface of the housing structure 29 and the top surface of the cover part 17, and the parts are fastened to each other by means of a bolt. The anti-wear spacer has trapezoidal openings 33 (see Figure 3) which are generally at the openings 27 in the cover part 17.

7 57699

A distribution device 34 is mounted inside the housing structure 29, i.e. the filtering collection chamber 29a, which can supply a countercurrent flow of the pressurized liquid, preferably the filtered liquid itself, in succession to the chambers 20 in repeated revolutions. At a time, one of the chambers 20 and the associated filter element group is washed by countercurrent rinsing, while the other filter element groups bounded by the other chambers 20 perform pressure filtration.

According to this example, the apparatus 34 includes a rotating pipe section or a rotating valve 35 mounted on a vertical shaft 36 actuated by a motorized adjustable speed actuator 37 for rotating the pipe section so that the oblique radial flow passage 38 of the valve section 35 is in succession with the chamber 20 can flow down to, as indicated by the arrows R, while the filtered liquid passes upward direction of the arrow R 2 direction of the other of the chambers 20 that are not connected to the washing tube passage 38. by rotating this channel is at all times upside-down in connection with the U-shaped annular feed channel 39 formed by a fixed annular body 40 about an axis and in one plane in opposite contact with the upper surface of the rotating tube part 35. This annular body has a neck 41 which, via a flexible pipe connection 42, communicates with an inlet pipe 43 which is part of the housing structure 29.

The vertical shaft 36 is fixed with a wedge or dowel pin to the pipe part 35 and can slide a small distance inside it, while rotating freely inside the annular body 40. The shaft passes upwards through the upper plate 31 through a suitable sealing sleeve 44. The lower end 45 of this shaft extends through the wear plate 32 into the central chamber 22. A compression coil spring 46 around the lower end of this shaft is enclosed between the retaining nuts 47 and the wear plate 32 forcing the annular body 40 into planar contact with the rotating tube portion and the tube contact 35. with the wear plate 32. The spring pressure is thus acted upon by a sleeve 48 mounted on the shaft, which acts on a vertical thrust ball bearing 49.

The rotating flow tube section shown in the embodiment of the slopes 3 and 4 has polished parallel top and bottom surfaces F-1 β 57699 and F-2 which are in contact with the similarly treated surfaces of the annular body 40 and the wear plate 32. This rotating pipe section or. the housing includes a base body or body which is a hollow truncated cone-shaped body 50 (see also Figures 2 and 3)> open at the bottom but closed at the top except for the feed opening of the sloping flow tube portion 51 which breaks the truncated cone-shaped base shape. The inflow area A-1 of the oblique tube channel itself and the outflow surface area A-2, inside the truncated cone-shaped hollow body part, are provided with a hub portion 52 which is wedged on the shaft 36 so that it can slip within a small distance.

It can be seen from the plan view from above of the pipe part in Fig. 3 that the oblique pipe part 51 extends outwards over the bottom diameter M of the truncated cone-shaped body part (T). The horizontal curved side portions 53 and 54 extend laterally in opposite directions from the lower end of the tubular portion 51, the side portions also being integral with the bottom of the frustoconical portion. These side parts together with the pipe part 51 form a radially projecting curved part 55 (see Fig. 3).

The side portions 53 and 54 act as effective closures that allow the valve tube to change from orifice 33 to the next without flow interruptions.

A preferred embodiment of the improved filter element will now be described with reference to Figures 8-14.

The implementation of Figure 8 shows that the filter element comprises a rigid tube 65, the wall of which is considerably thick and which is a porous liquid-permeable substance, for example porous polypropylene, which is highly resistant to chemicals and heat.

A flange 65a is attached to the upper end of this porous tube, while the lower end is closed by an end piece 66 attached to the tube _ and having holes 67.

The porous tube is surrounded by a hose of filter material or fabric, which is made so that it can stretch both longitudinally in the transverse direction. The lower end of this hose is closed by a sewing or stapling seam 69 and thus forms a downward pocket 70 below the lower end of the porous tube.

The upper part of this filter hose is in the shape of a bead 71, which is manufactured in a special way according to the present invention and has an outwardly extending edge. The round edge includes a relatively rigid O-ring 72, i. a ring of circular cross-section. This rigid ring, which is a substantially non-compressible material or plastic, is surrounded by the upper end of the filter fabric so that the fabric is stretched or spread around the ring and then turned inward over the ring and thus the fabric terminates inside the hose. The inverted portion of the filter material is secured by stapling 73 to the adjacent portion of the filter hose 73a, which occurs around the hose along a line near and below the ridge.

When the filter element is installed in the previously described pressure filter unit, the thickening part of the filter hose (see Fig. 8) is closed between the end plate 15 and the porous tube flange 65a and the thickening part of the hose and the flange are pressed down by the mounting plate 74.

The turbidity of the filtered liquid due to leakage of the filtration zones through the end plate is prevented by the sealing effect of the filter fabric surrounding the ring, which is preferably a non-compressible mixture or plastic. From the much enlarged detail showing the thickening in Figure 8a, it can be seen that any leakage from the space between the end plate and the ring is prevented by a compressed filter cloth between them which is around the ring. Leakage between the ring and the porous tube flange 65a is similarly prevented by an intermediate filter cloth.

The upper point P-1 and the lower point P-2 can have an optimal sealing effect due to what can be considered roughly as the line contact pressure at the top and bottom of the ring.

For the purposes of this invention, the filter hose is stretchable in both directions, i. both longitudinally and transversely. w Such bi-directional extensibility is achieved by making a strip or sheet 75 of filter cloth material (see Figure 10) in which the weft yarns run obliquely. That is, the yarns in each other's cuts intersect the long edges E-1 and E-2 of this filter fabric strip at an angle of about 45 °.

This filter cloth strip is formed, i.e. rolled, into a tube or hose S-1 (see Fig. 9) with a longitudinal seam or seams S-2, which connects the overlapping, longitudinal edge portions E-3 and + -4 of the filter cloth. In this way, the weft yarns become helical with respect to the axis of the hose, while the lower end of the hose is closed by the aforementioned transverse seam 69.

Figures 12, 13 and 14 illustrate a method of making a thickening section at the upper end of the unfinished filter hose of Figure 9.

The first step of the method shown in Figure 12 is to insert the ring into the upper end of the filter hose.

The second step shown in Figure 13 is to rotate the ring inside the hose in a horizontal direction that is transverse to the axis of the hose. This involves expanding the hose to form an annular outwardly directed bulge 76 to which the ring fits, at a distance "t" from the top edge 76a of the hose. -

The third step shown in Figure 13 involves turning the free, unexpanded top of the filter cloth through the ring and securing or stapling the inverted portion in place, as shown, with a circumferential seam 77 located below and near the ring, so that the ring is completely enclosed within the filter cloth. In this way, the ball has an outwardly directed, annular protrusion.

The finished filter hose or sock can then be pulled over the porous tube, with the inverted end portion 78 not forming any obstruction. This assembly of filter element, comprising a porous tube 65 and a hose 3-1, is then inserted into a corresponding hole in the end plate 15 of the filter unit, whereby the continuous outer surface of the hose allows a smooth insertion. The mounting plate 74 is then inserted and bolted to the end plate to effectively seal the sealing points P-1 and P-2 (see Figure 8a) at all points of contact of the filter elements covered by this mounting plate.

Claims (5)

11 57699 A filter sleeve for a pressure filter, comprising a horizontal plate (15) having holes for receiving tubular filter elements (16) comprising a liquid-permeable rigid tube (65) and a filter sleeve (68) formed of a resilient filter fabric so formed, the sleeve being expandable, the sleeve being adapted to fit on the rigid tube (65) and provided at its upper end with a radially projecting annular flange (71) for clamping between the horizontal plate (15) and the parallel planar rigid plate part (7 * 0) for holding the sleeve and sealing the flange being in the form of a thickening (71) obtained by wrapping the filter cloth around the ring (72), characterized in that the ring (72) is a substantially unchanged material and that the flexible filter cloth extends in an annular thickness around the ring (72) when the sleeve is attached; and then down through the ring, with the end portion of the sleeve attached around the sleeve below the ring. Filter sleeve according to Claim 1, characterized in that the filter fabric consists of a fabric whose wires normally intersect at substantially right angles to each other but run in a helically oriented direction with respect to the axis of the longitudinal filter element. Filter sleeve according to Claim 1 or 2, characterized in that the cross-sectional profile of the ring (72) is circular. - Patentkrav 1. A filter sleeve for a tricc filter in a horizontal plate (15) with a hdl for insertion of a filter element (16) in a wattage of a filter element (16) and a filter sleeve (65) and a filter sleeve (68) the sleeve is free from the expanderbar, the sleeve is free from the passage of the fly rope (65) and the other side of the belt is free from the radiant expander bar (71) for the fastening of the horizontal plate (15) and the middle parallell, soon, stel plattdel (7 * 0 försans fasthdllande och dstadkommande av en tätning- i det att flänsen har formen av ev vulst (71) framställd genom filterdu-kens lindning omkring en ring (72), kännetecknad av att ringen (72 ) the best of its ability to conform to the material of the filter and the flexible filter ducts in the case of fasteners