WEAR BAND SET FOR USE IN A WASTEWATER TREATMENT OR DISCHARGE INSTALLATION,
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION: This invention relates to sludge or sludge collectors for removing sludge from rectilinear sedimentation tanks and more particularly to a wear band assembly with the support of a scraper blade for use in sludge collection.
2. Description of the prior art: Sludge collectors are commonly used in wastewater treatment plants or discharge plants with the purpose of scraping the sludge or sludge settled at the bottom of a sedimentation tank and also for separating from the surface of the waste water the residues or floating foam. These mud collectors typically include a number of mud scraper blades, which are usually elongated members that extend across the width of the tank. The ends of the vanes are connected to drive chains that carry the vanes in a longitudinal circuit along the bottom of the tank and back on the surface of the water in order to perform the scraping and skimming functions. Rectangular sedimentation tanks used in wastewater treatment facilities typically include field-installed steel T-rails that have floor wear bars disposed on the T-rails to hold the pallet when mud is collected. The T-rails can be separated from each other with steel plate separation joint bars and can be secured to the concrete floors of the sedimentation tank by the use of common hard work equipment. Alternatively, the floors of the sedimentation tank can be placed without T rails and the wear bars can be directly mounted to the concrete floors. Because the wear bars are often made of a non-metallic material, such as UHMW, polyethylene, nylon or polymethane, these have a different coefficient of linear expansion than that of the concrete floors or T-rails to which they are mounted. , special design considerations must be made. Wide variations in ambient temperature are common within concrete tanks during installation or variations in water temperature when in final operation and therefore the wear bars become loose, buckled or misaligned in other ways. As a result, the pallets can get stuck and can result in breaking of the chains that support the pallets.
In addition, because the wear bars are typically secured to the T rail or to the concrete floor by means of a screw or pin, a portion of the surface of the wear bar is lowered to the presence of those fasteners, in addition, a large crowd may be required. of fasteners to secure the wear bars to the concrete floor or to the T rail, minimizing a global cost and the work required in the field and it is therefore desirable to have a wear bar that can be secured to the bottom of the settler tank without use screws or pin (bolt) such that the total surface of the wear bar can be used and installation is less expensive, easy to install and easy to replace when necessary. SUMMARY OF THE INVENTION It is produced from a wear strip for use in the treatment of waste water, the skill comprises at least one safety anchored plate at the bottom of the tank and at least one wear band disposed around the anchored plate, having a cross section in the form -c. It is also necessary to provide a wear bonding band for use in wastewater treatment, the ability comprises a plurality of plates anchored in order in a longitudinal direction, each anchor plate being secured to the bottom of the tank and a plurality of wear bars, each wear bar has a c-shaped cross section and is arranged around a number of anchored plates. We must also provide systems in the treatment of wastewater, comprising sedimentation tank, receiving expansion of the wear band at the rear end of the sedimentation tank and the wear bond band disposed on the bottom of the tank, the wear-bound band in the system of anchored plates arranged in a longitudinal direction, each being secured to the bottom of the tank and to a plurality of wear bands, each having a c-shaped cross section being arranged around a number of anchored plates. The plurality of wear bands can expand within the receiving expansion of the wear band, when the ambient temperature of the concrete pond during installation or the temperature of the water during operation increments. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view of a partial plane of the vane disposed in the wear bonded web of the present invention. Figure 2 is a cross section of a wear band. Figure 3A is a top view of an anchor plate, Figure 3B is an end and view of the anchor.
Figure 4 is a sectional view taken along lines C-C of Figure 1. Figure 5A is a top view of a stop plate. Figure 5B is a side view of the stop plate. Figure 6 is a sectional view taken along the lines AA of Figure 1. Figure 7 is a sectional view taken along lines BB of Figure 1. Figure 8 is a sectional view of rear end of the sedimentation tank. Figure 9 is a sectional view taken along lines X-X of Figure 8,
Description of the preferred embodiments
Referring now to Figure 1, a scraper blade 10 disposed on the wear band assembly 12 of the present invention is shown in plan view. The wear band assembly 12 comprises at least one wear band 14 and an anchor plate 34. With reference also to Figure 2, the wear strip 14 has a c-shaped section. The wear band 14 can have, for example, a length of 3,048 meters and a sectional area of 17.74 cm. The c-shaped section is formed of a horizontal base 16 which can have a length 18 of 10.79 cm and a thickness 20 of 1.27 cm, transverse rods 22 which can have a height 24 of 1.58 cm and a thickness 26 of 0.79 cm and flanges 28 which can have a height 30 of 0.79 cm and a height 32 of 0.95 cm. A plurality of wear bands are aligned along a longitudinal direction forming a waste bar 15. The wear band 14 is preferably extruded from UHMW polyethylene which, in the preferred embodiment of the invention, is virgin material certified in accordance with ASTM specification D-4020-81, with a molecular weight of 4.0 million or greater. , a relative abrasion resistance of twelve, an intrinsic viscosity of twenty-four or greater and a zero water absorption. Referring also to Figures 3A and 3B, an anchor plate 34 of the present invention is shown, Preferably, the anchor plate 34 has a plate 36 on the top which may have a length 38 of 8.89 cm, a width 40 of 8.89 cm and a height 42 of 0.476 cm. The anchor plate 34 is secured to the bottom 44 of the tank 43 in such a way that the upper plate 36 is generally parallel with the bottom 44 of the tank. Two legs 46 are disposed on the bottom side of the upper plate 36 along the longitudinal direction of the wear bar 15 which may have a width 48 of 0.47 cm and a height 50 of 1.27 cm. Preferably, in the example provided, the longitudinal ends of the legs 46 are at a distance from the ends of the upper plate 36 approximately 0.635 cm at each end. Further, the legs 46 may be positioned such that they form extensions 52 in the upper plate 36 because the sides of the legs 46 are on the sides of the upper plate 36 approximately 0.95 cm. The anchor plate 34 further comprises a bore 54 which can be centrally located on the anchor plate. Preferably, hole 54 is a hole with a diameter of 1.11 cm having a countersink for a diameter of 0.95 cm for a screw 62 with a flat head. A hub 56 is disposed on the lower side of the upper plate 36 around the bore 54. The cylindrical extension can have an external diameter 58 of 1.90 cm, an inner diameter that couples with the diameter of 0.95 of the hole 54 and a height 60. of 1,428 cm. The height 50 of the legs 46 is slightly smaller than the height 60 of the hub 56 to allow some gap or clearance in case the bottom of the tank 44 is uneven. Referring also to Figure 4, a flat head screw 62 secures the anchor plate 34 to the bottom 44 of the tajik. A plastic anchor 64 can be used to help secure the screw 62 to the bottom 44 of the tank. The anchor plate 34 receives the wear band 14. Specifically, the flanges 28 and the stems 22 of the wear strip 14, preferably slide around the extensions 52 of the anchor plate 34. Preferably, there are at least three anchor plates for each 3048 m section of the wear band 14. In addition, preferably, an anchor plate 34 is disposed at approximately 15.24 cm from each end of the given wear strip 14. As stated, the wear bands 14 may each have a length of 3,048 meters and the wear bands may be aligned in a longitudinal direction. The wear bands 14 can be aligned, resulting in a wear bar 15 which can have, for example, a length of 91.44 meters. Preferably, there is a space 66 of 1.27 cm between the wear bands 14 when the wear band assembly 12 is originally installed. This allows the wear bands 14 to extend a little along the longitudinal direction when the temperature is increased. In addition, the ends of the wear band 14 will be bevelled at approximately 45 degrees as is commonly done in the industry for uniform transition of the blade movement. The anchor plate 34 is preferably non-metallic and is molded as a single unit of polypropylene, polyethylene-UHMW, or a similar non-metallic material. In the preferred embodiment of the present invention, polypropylene has the following properties: a tensile strength of 35 kg / cm and an elongation of 10-20%, a tension modulus of 0.01x10 'kg / cm, a Rockwell hardness of 80-110 and a flexural modulus of 0.01 to 0.02xl05 kg / cm2, a specific gravity of 0.905, 3 a specific volume of 232 cm / kg and a water absorption of 0.01-0.03% in 24 hours based on to a material with a thickness of 0.31cm. Referring now to Figures 1, 5A and 5B, the wear band assembly 12 may further comprise a stop plate 70 which may be formed of stainless steel number 316. The stop plate 70 comprises a horizontal base 72, a first extension 74 and a second extension 76. Horizontal base 72 comprises an orifice 78. Preferably the horizontal base 72, the first extension 74 and the second extension 76 are welded together. Alternatively, they may be formed from a single piece of stainless steel material or from the same material as the plate 34. The first extension 74 and the second extension 76 are dimensioned such that the horizontal base 72 is generally parallel with the bottom of the base. tank 44 and such that there is sufficient space such that the plate 70 of tqpe can slide under the anchor plate 34. The horizontal base 72 can have a length of 7.3 cm, a width of 5.7 cm and a thickness of 0.64 cm. The first extension can have a length of 0.95 cm, a width of 10.79 cm and a thickness of 1.9 cm. The second extension 76 can have a length of 0.63 cm, a width of 2.54 cm and a thickness of 0.63 cm. Preferably, all corners and edges of the horizontal base are polished in order to remove any edge at the corners and edges. The bore preferably has an orifice diameter of 2.06 cm, which is centered approximately 4.52 cm from the edges of the extension 74. With reference also to Figures 6 and 7, an anchor plate 34 is secured to the bottom 44 of the tank at one end of the plurality of wear bands, which are disposed near the trip discharge end 80 of the paddle 10 (i.e., near the sludge discharge end 80 of the concrete tank 43) , as best illustrated in Figure 1. The stop plate 70 is slidably received at the bottom end of the anchor plate 34. A screw 62 secures both the stop plate 70 and the anchor plate 34 to the 44 bottom of the concrete tank via the use of a 64 plastic anchor. The screw is disposed through the bore 78 in the stop plate and bore 54 in the anchor plate. The stop plate helps prevent the expansion of the plurality of wear strips 14 toward the fan discharge end 80 of the concrete tank 43. With reference now to figure 1, the scraper palette 10 may be, for example, a pallet manufactured by the company FMC Corporation, applicant transferee. The pallet 10 can be formed, for example, of fiberglass and can p
have scrapers 82 and 84 of floor mounted in the center and the ends, respectively, of the pallet 10. The scrapers of the floor can be adjustably mounted to the pallet 10 via screws 86, grooves 85 and 87 in the scrapers 82, 84 and ranu -ras 89 in the pallet 10, as seen in figure 7, the pallet 10 can have a first pair of wear shoes 88 that can be secured to the pallet 10 through bolts 90. The first pair of shoes 88 of Wear can be used when the paddle is performing the skimming or defoaming operation. The pallet 10 can have a second pair of wear shoes 92 that can be secured to the pallet 10 through pins 94. The wear shoes 92 contact the surface of the wear bar 15 during the sludge collection operation. . The bolts 93 can - - - assure - to the pallet 10 a chain, not illustrated, for the transport of the pallet, The polyethylene UHMW, from which the bands 14 are formed, tend to have a high expansion coefficient linear as described above. The expansion generally occurs along the longitudinal direction of the wear bands 14. As mentioned above, the stop plates 70 prevent the expedition of the wear bands 14 towards the discharge ends 80 of the tank 43. In order to allow the expansion of the plurality of wear bands 14, a cavity 98 is provided. Cemented is formed at the rear end 96 of the tank 43, as shown in Figures 8 and 9. In addition, a wear bar expansion cavity 99 is formed in the cemented cavity 98. The wear bar expansion cavity 99 is an indentation in the formation of the cavity 98 cemented in the region where the wear bar 15 is located in order to allow the expansion of the wear strips 14 towards the back 96 of the tank 43. As best seen in Figure 8, the cemented cavity 98 is formed in the rear portion 96 of the tank 43 in a region between the bottom 44 of the tank and the rear side wall 100 and is typically curved in section to allow that the pallet 10 moves downwards while the waste is collected in the back corner before the scraping operation enters. Alternatively, the wear bar expansion cavity 99 can be formed directly in the concrete tank 43, without the use of a cemented cavity 98. The anchor plates 34 serve as a guide for the expansion of the wear strips 14 toward the rear of the tank and for the contraction of the wear strips in a reverse direction from the rear of the tank, the dimensions of the cavity 99 expansion of the wear bar and the cavity 98 cemented depend on the length of the tank 43. Specifically, the longer the tank is the greater the collective amount of expansion caused by the various wear bars 14. In addition, the 1.27 cm spacing of the wear bands 14 during installation, allow an additional space in which a given wear band can be expanded before touching an adjacent wear band 14. When the wear bar 15 is approximately 72.6 meters in length, the cavity 99 for expanding the wear bar will extend approximately 35.56 cm along the longitudinal direction of the wear bar 15 from where the wear bar is calculated to the end (ie, 35.56 cm from the center line of the shaft 101 that returns the paddles 10 downward for the scraping operation). In addition, the cavity 99 for expanding the wear bar is dimensioned in such a way that the wear bar 15 can easily be extended into the cavity 99 for expanding the wear bar. When, for example, the expansion bar 14 has a dimension 18 of 11.43 cm, as shown in Figure 2, the width of the cavity 99 for expanding the wear bar may be 17.78 cm. As shown in the example of figures 8 and 9, the back wear strip 14 has extended approximately 30.48 cm into the wear bar expansion cavity 99. The preferably cemented cavity 98 is configured in such a way that it starts in the region around the center line of the shaft 101 and can extend, for example, by a distance beyond the expansion cavity 99 of the wear bar several centimeters As also seen in Figure 8, there is a clearance or gap of 0.31 c between the edge of the wear bar 15 and the bottom 44 of the tank. This separation is desirable because the bottom 44 of the tank may be slightly uneven. The anchor plates 34 can first be installed via the use of screws 62 and plastic anchors 64 to secure the anchor plates 34 to the bottom 44 of the tank. In addition, a stop plate 70 can slide under the plate 36 of the anchor plate. stop of the anchor plate 34 close to the discharge end 80 of the tank 43. Similarly, a screw 62 and a plastic anchor can be used to secure the stop plate 70 and the anchor plate 34 to the bottom 44 of the tank, The anchor plate 34 closest to the discharge end 80 of the tank 43 can be secured to the bottom of the tank 44 approximately where the discharge end 80 of the tank 43 begins. The extension 74 of the stop plate 70 prevents the bar 15 from of wear extends to the discharge end 80 of the tank 43, if the temperature is increased and expansion occurs, the wear bands 14 may then be slidable on the extensions 52 of the anchor plates 34. As previously stated, preferably, there are three anchor plates 34 for a given wear strip 14, the first and the second being approximately 15.24 cm from each end of the wear strip when a band is used. of wear of 3,048 meters and the third is placed approximately halfway between the first and second anchor plates during the initial installation. However, as stated above, the anchor plate 34 closest to the discharge end 80 of the tank 43 is not positioned 15.24 cm from the end of the wear strip 14 but rather at the end of the wear strip. The anchor plate 34 closest to the rear end of the tank, preferably is located 15.24 cm from the beginning of the cavity 98 cemented during the initial installation. If a given wear band 14 is damaged during the sludge collection process, the old wear band can be easily removed by cutting the old wear band and sliding a new one. It will be recognized that, although the present invention has been described in connection with its preferred embodiments, those skilled in the art can develop a wide variety of structural details without departing from the principles of the invention. Therefore, the annexed clauses have been constructed to cover all equivalents that fall within the true scope and spirit of the invention,