MXPA97001191A - Side member assembly for an inferal drain system - Google Patents

Abstract

The present invention relates to an elongated side member assembly for use in a lower side discharge distribution system which is adapted to be generally placed horizontally under a bed of granular material that must be periodically backwashed with fluids, comprising of elongate, generally planar base plate, and an elongated mesh member, having a support holding portion directed upwardly, and which is mounted on its elongated lateral edges to the elongated lateral edge portions of the plate, exiting the member of base plate from a rigid extruded plastic, said mesh member having an internal support portion comprising a plurality of members in the form of an extruded plastic channel, having perforated and elongated internal fabric portions, portions of external gossip that is they extend radially outwards, to which a plurality of plastic wires are welded in a direction in a direction generally normal to the direction of the outer rib portions, to form a plurality of narrow slot-shaped openings elongate projections formed on a pair of plurality of channel-like members defining the elongated lateral edges of the member of mesh, the elongate projections extending in a generally radially inward fashion, one towards the other of the length of the mesh member, the elongated base plate member generally dying extending channels formed verically on the upper surface of its opposite lateral edges. , and extending along its length, mounting the opposite elongated lateral edges of the mesh member in the channels, each of the channels in the base plate member having internal and external and separate parades, the inner wall having a Slot and recess portion extending inwards separated from the top surface of the pair internal ed, the grooved portion complementary to, and serving to retain the elongated projection formed on one of the opposite lateral edges of said mesh member against upward movement, and at least one elongate flexible sealing element placed at least one wall of each of the channels that extend vertically, and a surface of said member of evil

Description

SIDE MEMBER ASSEMBLY FOR ON LOWER DRAIN SIDE SYSTEM BACKGROUND 1. Field of the Invention This invention pertains to lower side drainage systems, such as those of the type used in a gravity filter bed. 2. Related Art and Other Considerations U.S. Patent No. 5,156,738, incorporated herein by reference, illustrates a lateral bottom drainage system of the type having a curved distributor member or mesh positioned above a base plate. flat As illustrated in U.S. Patent No. 5,156,738, and as understood by those skilled in the art, the lateral bottom drainage system is placed under a bed of material, such that the liquid normally water, that comes out of the spill channels that are above the bed of material, passes through the medium. During normal operation, the water that has passed through the bed of material falls into the lower lateral drainage system, and particularly toward the upper concave surfaces of the mesh. The upper concave surface of the mesh has perforations such as thin grooves that are dimensioned to retain the particles that make up the bed of material. The water that passes through the mesh is subsequently discharged from the lower side drainage system. Opposite to normal operation, a backwash mode is used to clean the material. In the backwash mode, water and air are directed upwards through the perforations of the mesh and bed of material in a uniform manner, so that the material previously filtered and captured by the bed of material, is It will collect and be carried upwards, where it will be discharged through the spill channel. The lateral bottom drainage system shown in U.S. Patent No. 5,156,738 is formed of stainless steel, and has its mesh portion positioned between two lateral edge portions turned upwardly of its elongated planar base plate. Its mesh portion is formed by helical winding and by welding a metal wire to a channel base support, as described in United States Patent Number 4,096,911. The meshes and base plates that form the side member assemblies for the lower side drainage systems can be very large, often measuring as much as 9 meters, but more typically are approximately 6 meters. In the prior art, these side member assemblies were formed of metal, and in accordance with this, they were not only heavy to transport but were very problematic, due to their weight, to be assembled with other units at the point of use. In addition, where the assemblies were to be used with seawater or brackish water, they were subject to corrosion, even when they were made of stainless steel. Also, since stainless steel is very expensive, the base plates of metal units are usually relatively thin, allowing them to be convalesced during use, unless a substantial number of clamping bars are provided to hold them in place and flat against the floor. Since considerable labor is required to mount the fastening bars with screws to the concrete floor of the filter bed, it can be appreciated that a side unit requiring fewer fastening bars would be very desirable. SUMMARY OF THE INVENTION It is an object of the present invention to provide a side assembly that is much less expensive and weighs much lighter than the previously used metal units, and yet, capable of supporting the bed weight of the material and the different water and air pressures present at different times during the collection and backwash cycles. It is an additional object to provide a side assembly that is more resistant to corrosion than metal meshes, rigid enough to require fewer fasteners, and have its mesh and base sealed in such a way as to allow flexion under load to reduce stresses and dissipate the effects of water hammers produced by any sudden opening and closing of the valves that control the flow of water and air in the system. These and other objects are obtained by an elongated side member assembly as claimed in the subsequent claim 1, which has flange portions directed inward on its lateral edges, retained by grooves recessed in a vertical channel formed on the edges of a rigid plastic base plate member extruded. In a preferred embodiment, the mesh and the base plate are telescopically assembled with each other, and sealed with flexible plastic strips that are coextruded with the rigid base plate member. In a modified embodiment, the flange portions of the mesh are forced down onto surfaces, and cam over the inner side walls of the channels of the base plate, until they are attached in the recessed slots. They are then sealed and retained by elongated plastic rods compressed in the space between the outer channel walls and the edge of the meshes. BRIEF DESCRIPTION OF THE DRAWINGS The embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a cross-sectional view taken on line 1-1 of Figure 2, which shows a side member assembly in accordance with a first embodiment of the invention, for use in a lateral bottom drainage distribution system. Figure 2 is a fragmentary side view, partially broken away in parts, of the side member assembly of Figure 1. Figure 3 is an end view showing one of the end caps covering the ends of the side member assembly shown in Figure 2. Figure 4 is a perspective view of a portion of the side member assembly of Figure 1, showing a mesh that is telescopically sliding to an interlock position relative to a base plate. Figure 5 is an end view of the base plate portion of the side member assembly of Figure 1. Figure 6 is an end view similar to the Figure 4, but showing a second embodiment of the invention, wherein the mesh member is about to be forced down against the base plate member to secure the two members together.

Figure 7 is an end view similar to Figure 6, but showing the members after they have been adjusted to each other. DETAILED DESCRIPTION OF THE INVENTION The present invention provides embodiments and modes of inserting a mesh portion of a side member assembly into a base plate portion of the side member assembly. The embodiments of the present invention are preferably and congenially made of plastic, and preferably of a polyvinyl chloride (PVC) plastic. Figures 1 and 2 show a side member assembly indicated generally at 10 according to a first embodiment of the invention. The side member assembly 10 has a tubular shape, and preferably includes a curved mesh member 20 and a rigid extruded base plate member 22, and is closed at its ends by molded plastic end cap members 23. The mesh curve 20 has the geometric shape of a sector of a hollow cylinder, such that a semicircular open region 24 is formed between the mesh 20 and the base plate 22. The mesh 20 has a central axis running parallel to the arrow 26 in Figure 4 (ie, perpendicular to the sheet of Figure 1). The mesh 20 preferably includes a plurality of closely spaced plastic wires 28, which are released at each of their intersections 29 to a plurality of extruded channel ribs extending radially outwardly 30, to define narrow grooves 31 for retention of the material and the collection of the filtered liquid. The channel ribs 30 define a plurality of channel portions 32 formed in an internal mesh support portion comprising segments 34. Most channel portions 32 have perforated internal portions containing small holes 35 (FIG. 4) cooperating with one another. with others to form a flow distribution system, to control in a uniform manner the flow of water and air entering through the adjustment seal 36 during the backwash operation. The adjustment seal 36 is preferably made of nitrile or neoprene rubber, and is mounted in a hole 36 'in the center of the base plate 22. The purpose and placement of these openings 35, is to ensure that there is more than one open area for flow in the lower half of the opening of the mesh 24, compared to the upper half, as is well explained in U.S. Patent No. 5,156,738. Although the pattern of holes in the openings 35 is not visible in the drawings, the holes are preferably of a diameter of approximately 3.2 millimeters. In Figure 1, three support segments 34 are provided on either side of the center of the mesh, with each segment including four integral channels 32. In the two upper support segments 34 ', the uppermost channels 32a, preferably have no holes , while the three lowermost channels 32b each have two orifices per 30 centimeters in length of the lateral member. In the lower support segments 34"the uppermost channel 32c has two holes by 0.3048 meters, the next two channels 32d have eight holes by 30 centimeters, and the lowermost channel 32e has no holes.In their side edges 37, which run parallel to the arrow 26, the mesh 20 has the radially inwardly-directed support flange portions comprising elongated portions 38, formed in the lower portion of the lower support segment 34". Figures 2 and 3 show an end cap member 23 which is molded of polyvinyl chloride (PVC), and has a groove formed around its interior, which is adapted to overlap and surround the ends of the mesh 20 and the base plate 22. The end caps are preferably joined to the members 20 and 22 with cement for poly (vinyl chloride). As best seen in Figures 1 and 4, the base plate 22 is configured to mate with the support flange portions of the mesh 38, such that the mesh member 20 can slide longitudinally to an interacure coupling with the base plate member 22. Figure 4 shows the mesh member 20 which is slid longitudinally inward of the base plate 22 in the direction of the date 39. To accommodate the support flange portions 38 of the mesh 20, the base plate 22 is provided with a pair portions recessed slots 40 which are complementary to the flange portions 38. In addition to the recessed slot portions 40 that are formed in the side edge portions 42, the base plate 22 is contoured to have a flat central portion 44. Contiguous to either side of the central portion 44 of the base plate, are the base plate ramp portions 46 that form a bridge or a ramp between the central portion 44 and the edge portions 42. The ramp portions 46 cooperate with the central portion 44 to increase the stiffness of the base plate 22, and to make it more resistant to bending than the metal base plates of the prior art, such as are shown in the United States of America Number 5,156,738. In a preferred embodiment, the cross-sectional thickness of the base plate is approximately 9.7 millimeters in its central portion 44, while the radial thickness of the mesh member 20 is approximately 12.7 millimeters. In Figure 5, the recessed slot portion 40 of the base plate 22 is shown in greater detail. It is formed as part of the vertically upwardly extending channels 54, which include the bottom wall of the channel 60, the outer side wall. 62, and the internal side wall 64. The recessed slot portion 40 forms a lower cutting portion in the inner wall 64 below the upper lip portion 66. The open internal space 68 of the channels 54 is sized to make it larger that the flange portions 38 and the side edge portions 37 of the mesh member 20, to facilitate the longitudinal insertion of the side edge portions 37 into the channels 54. Since the side assemblies 10 are typically 6.1 meters or more of length, and more than 25.4 centimeters in width, we prefer to assemble them by mounting the 20 mesh member in an accessory "(not shown) on a table (not shown), while a cable assembly is used. (not shown) for pushing the base plate member 22 to telescopically engage with the mesh member 20. Since there must necessarily be a rather loose fit between the mesh member and 20 and the base plate 22 to accommodate the operation of Assembled, a sealing element is provided to prevent leakage of unfiltered liquid into the internal space 24. The sealing member includes flexible elongate sealing strips 70 and 72, which are preferably formed of a flexible polyvinyl chloride (PVC) material , such as that sold under the registered trademark GeonR 7,000 produced by BF Goodrich Company. The flexible polyvinyl chloride (PVC) sealing strips 70 and 72 are co-extruded and therefore integral with the base plate member 22, which is preferably formed of a rigid polyvinyl chloride (PVC) material sold under the name GEONR 8,700. The wires of the mesh 28, and the grooved support segments 44, which comprise the mesh member 20, are also preferably made of a polyvinyl chloride material. The sealing strips 70, 72 each extend upward and inward, to the inner space 68, and are long enough to flex to a more vertical position as they engage the side edges 37 of the mesh during the assembly operation. The outer strip 70 will tend to force down to contact the outer surface of the mesh member 20 during normal operation, when the lateral one is collecting water, since the pressure of the water is higher above the side than inside it. During backwashing, the pressure of water and air inside the interior of the mesh 24 will tend to keep the inner sealing strip 72 engaged with the inner surface of the mesh. Figures 6 and 7 show a second embodiment of the invention, wherein the mesh member 120 is adapted to be assembled to the base plate member 122 by depressing the side edge portions 137 downwards, into the channels extending vertically toward up 154. The upper lip portion 166 is formed to include an angled cam surface 166 ', which will contact the lower corner surface 137' of the side edge portion of the 120 mesh member, and force it to move progressively until out until it has moved past the lip portion 166, at which point, it will snap back into its normal position. At this point, the radially inwardly directed flange portions 138 will be placed in the recessed slot portions comprising elongated projections 140. Since the channels 154 must be wide enough to accommodate the outward movement of the mesh edge portions 137 , a sealing and retaining element is forced downward in the form of a flexible rod member 170, preferably formed of plastic or rubber, into the space between the outer wall of the channel 162, and the outer wall 137"of the member. 120. A slot 164 'formed in the inner wall of the channel, secures the rod member 170 in place, and improves the seal.A particular advantage of the side assembly of the present invention is that it requires much less the sense of installation time and materials for anchoring it in position, than the metal side assembly shown in U.S. Patent Number 5,156.7 38. For example, for a length of 6.1 meters on the side, 4 fastening bars anchored in the concrete floor of the filter would be needed with 9.5 mm screws for the lateral metal assembly of the United States Patent Number 5,156,738 , since the relatively thin baseplate member may tend to condense under the pressure exerted on the inside of the assembly during backwashing. The stiffness of the base plate 22, 122 of the present invention, which is improved by the angled connection portion '46, is sufficient to normally require only said clamping bar in the center of the side. A clamping bar is required in this position, because it overlaps the location of the connection 36 (Figure 2), which carries water and air inward during backwash. These fluids impact the upper internal surface of the mesh member with substantial force, and tend to lift it. The ends of the side assembly can be fastened to the floor with simple staples 76 that can be quickly anchored with expansion clips rather than with. large screws, the staples can be coupled with either the lower edge of the end caps 23, or with the upper external surfaces of the side edge portions 42. Another advantage of the plastic side assembly, compared to that of stainless steel, is that materials such as anti-pollution agents, such as fungicides or bacteriostatic materials such as copper, should be able to be mixed in the plastics used to make the side, before they are extruded, in order to give the properties of the side that are not can achieve in a metal mesh. Although the invention has been shown and described particularly with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that different alterations may be made in the form and in detail thereof, without departing from the invention.

Claims (10)

1. NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS 1. An elongated side member assembly (10) for use in a system of bottom drainage side distribution which is adapted to be placed generally horizontally under a bed of granular material that must be backwashed periodically with fluids, comprising an elongated base plate member (22), generally flat, and an elongated mesh member ( 20), which has a retention portion of material directed upwards, and which is mounted on its elongated side edges (37) to the elongated side edge portions (42) of the base plate, characterized in that the base plate member ( 22) is formed of a rigid extruded plastic, the mesh member (20) has an internal support portion comprising a plurality of plastic channel-shaped members and xtruid (34), having perforated and elongated internal tissue portions, external rib portions extending radially outwardly (30), to which a plurality of plastic wires (28) are welded in a direction generally normal to the direction of the outer rib portions (30), to form a plurality of narrow slot-shaped openings (32); elongate projections formed on a pair of plurality of channel members (34) defining the opposite elongated lateral edges of the mesh member (20), the elongated projections (38) extending in a generally radially inward, one toward the other, along the length of the mesh member, the elongated base plate member (22) having channels extending in vertically (54) formed on the upper surface of its opposite lateral edges (42), and extending along its length, the opposite elongated lateral edges (37) of the mesh member (20) being mounted on the channels ( 54), each of the channels of the base plate member having separate internal and external walls (64, 62), the inner wall (64) having a slotted and recessed portion (40) extending inwardly spaced from the top surface of the inner wall, the slotted portion (40) being complementary to, and serving to retain the elongated projection (38) formed on one of the opposite lateral edges (37) of said mesh member against upward movement, and when less an elongate flexible sealing element (70, 72) positioned between at least one wall (62, 64) of each of the vertically extending channels (54), and a surface of said mesh member (20). An elongated side member assembly according to claim 1, characterized in that the opposite lateral edges (37) of the mesh member, and the channels (54) of the lateral edges of the base plate member, have a elongate complementary cross-sectional shape in the edge regions, where they are held against relative movement upwards one in relation to the other, in such a way that they can be assembled telescopically one in the other. An elongated side member assembly according to claim 1 or 2, characterized in that the elongate flexible sealing element comprises a pair of flexible plastic strips (70, 72) that are integral with the vertical walls ( 62, 64) of the channels of the base plate member, said flexible plastic strips (70, 72) extending generally upwardly and one toward the other, to make contact with the inner and outer surfaces of the mesh member (20). An elongated side member assembly in accordance with claim 1, characterized in that the internal walls (166 ') of the base plate member channels., which are located immediately above the grooved and recessed portions (140) extending downward, are formed at an angle to the vertical, which allows the elongated projections (138) of the opposite lateral edges of the mesh member (120 ) move progressively away from each other when a downward force is applied to the mesh member (120) during an assembly operation with the base plate member (122), said mesh member being sufficiently elastic to cause the elongated projections (138) fit into the slotted and recessed portions (40) after moving down along the internal walls of the channels. An elongated side member assembly in accordance with claim 1, characterized in that each of the outer walls (162) of the channels formed in the base plate member (122) has a cutting groove. lower (162 ') therein, which serves to retain an elongate flexible sealing member (170). An elongated side member assembly according to claim 1, characterized in that the vertically extending channels formed in the base plate member (122) are sufficiently wide to accommodate the downward passage of the legs. elongate projections (138) during the vertical assembly of the mesh member (120) to the base plate member, and an elongate flexible member (170) that is adapted to be placed on the outer portion of each of the channels, to force the inner edges of the mesh member towards the internal walls (166 ') of the channels, after the mesh member has been assembled to the base plate member, such that the elongated projections (138) of the mesh member are retained by the recessed portions (140) of the base plate member, said elongated flexible members (170) providing a seal between the mesh member (120) and the outer walls (162) of said base plate channels. and. An elongated side member assembly according to claim 3, or claims 4 to 6 when dependent on the 3, characterized in that the pair of flexible plastic strips (70, 72) are integral with the member of rigid plastic base plate (22). 8. An elongated side member assembly according to claim 3, 7 or any of claims 4 to 6 when depending on the 3, characterized in that the flexible plastic strips (70, 72) and the base plate of Rigid plastic are formed from different types of polyvinyl chloride (PVC) plastic. 9. An elongated side member assembly according to claim as claimed in any of the foregoing claims, characterized in that the ends of the side member assembly are closed by molded plastic end caps (23), which include an internal groove that surrounds both to the mesh member (20) as to the base plate member (22). An elongated side member assembly in accordance with claim 1, characterized in that the base plate member (22) includes a flat central lower portion (44), and angled upward connection portions (46). ) that connect the central portion with the shore portions (42).