Customizable field-based sludge scrapers and related methods.

Abstract

DEPCT6910 / 02 / 2569 Sludge scraper assembly for attachment in the tank of chain systems and scraper blade for... The wastewater treatment tank has a width according to the tank range, and includes a sludge scraper assembly, including the scraper itself. Sediment with scraper width and scraper height, linked by adhesive that can be attached. Removable type with sludge scraper and designed for connection to the collector chain, wear-resistant side. The return, which can be removed, is attached to the sludge scraper and the wear-resistant side of the transmission, which can also be removed. It comes with a sludge scraper; the sludge scraper is made of polymer material such as plastic. Reinforced with fibers, the sludge scraper is designed to allow for adjustment of the scraper's length at the front position. The work involves adjusting the length of the scraper to position the sludge scraper within the width range of the tank system. Sludge scraping may also include wall brackets, head shafts, short shafts, and related components;

Description

TITLE OF THE INVENTIONField Configurable Sludge Scraper and Related MethodCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 63 / 521,358; filed June 16, 2023 and titled, “Field Configurable Sludge Scraper and Related Method;” the entire contents of which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION

[0002] Sludge scrapers and related assemblies for wastewater chain-and-flight sludge collection systems are dominated by one-piece custom scraper designs that span a wastewater or sludge tank width WT of the sludge tank (Fig. 1). Prior art custom sludge scrapers assembled as part of a sludge scraper assembly and mounted in a wastewater treatment tank is shown in Fig. 1. These sludge scrapers must be predesigned and customized to accommodate the specific sludge tank. The prior art sludge scrapers have pre-designed and fixed scraper lengths and dimensions that fit within the dimensions of the sludge tank, including the tank width WT and chain centerlines. The prior art sludge scrapers are cut to their customized size before shipping to the field location. The customized sludge scrapers do not function if tank measurements are incorrect or the design of the wastewater tank changes after the scraper is manufactured. Significant time and efforts are wasted when the customized sludge scraper arrives at the tank location and does not fit within the tank or requires any adjustment.

[0003] It would be desirable to design, construct and deploy a sludge scraper and related assembly for a wastewater tank that utilizes standard parts for multiple sized tanks. It is also desirable to design, develop and deploy a sludge scraper and scraper assemblies that facilitate assembly and sizing during installation in the field. The preferred present invention addresses the shortcomings of the prior art systems.BRIEF SUMMARY OF THE INVENTION

[0004] Briefly stated, the preferred invention is directed to a sludge scraper and a related assembly that is found in chain-and-flight sludge collection systems. The chain- and-flight sludge collection system is used to clarify water in the water and wastewater treatment industries. The sludge scraper spans the transverse width of the tank and is propelled forward by a chain and sprocket drivetrain. The sludge scraper typically serves two purposes, including (1) to transfer settled sludge on the bottom of the tank to a sump pit or central collector and (2) to transfer floating debris on the water surface to a collection pipe or trough.

[0005] Briefly stated, a preferred embodiment of the invention is directed to a sludge scraper assembly for mounting in a wastewater or sludge tank of a chain and flight system for treatment of wastewater wherein the tank has a tank span width. The sludge scraper assembly includes a sludge scraper having a scraper length and a scraper height, attachment links removably mountable to the sludge scraper and configured for connection to a collector chain, return wear shoes removably mountable to the sludge scraper and carry wear shoes removably mountable to the sludge scraper. The sludge scraper is constructed of a polymeric material. The sludge scraper is configured for adjustment to cut the scraper length in a field location to a working scraper length to accommodate the sludge scraper within the tank span width. The sludge scraper is configured for adjustment of the removeable components to different positions along the scraper length to accommodate different chain centerlines and positions of the wear components.

[0006] In another aspect, a preferred embodiment of the invention is directed to a sludge scraper assembly for mounting in a tank having a collector chain for wastewater treatment. The sludge scraper assembly includes a sludge scraper having a scraper length, a first head, a second head and a scraper leg connecting the first head to the second head. The sludge scraper is constructed of a polymeric material. The second head has a slot, which may be comprised of a second front slot, extending along the scraper length that opens into a channel in the second head, which may be comprised of a second front channel. The sludge scraper assembly also includes plurality of threaded nuts positionedwithin the channel. The plurality of threaded nuts includes a first nut having a first threaded opening and a second nut having a second threaded opening. The first and second threaded openings face out of the slot in the second head. The sludge scraper assembly also includes an attachment link removably mountable to the sludge scraper with the first and second nuts. The attachment link is configured for connection to the collector chain.

[0007] In a further aspect, a preferred embodiment of the invention is directed to a sludge scraper assembly for mounting in a tank having a collector chain for wastewater treatment. The tank has a tank span width. The sludge scraper assembly includes a sludge scraper having a scraper length, a first head, a second head and a scraper leg connecting the first head to the second head. The second head has a slot, which may be comprised of a second front slot, extending along the scraper length that opens into a channel in the second head, which may be comprised of a second front channel. The first head has a slot, which may be comprised of a first front slot, extending along the scraper length that opens into a channel in the first head, which may be comprised of a first front channel. The scraper length is configured for field modification such that the sludge scraper fits within the tank span width. The sludge scraper assembly also includes an attachment link removably mountable to the sludge scraper that is configured for connection to the collector chain. The sludge scraper assembly further includes a plurality of fasteners configured for mounting the sludge scraper to the attachment link. The plurality of fasteners includes a first fastener positioned in the channel, which may be comprised of the second front channel, and exposed through the slot in the second head, which may be comprised of the second front slot, and a second fastener positioned in the channel in the first head, which may be comprised of a first front slot, and exposed through the slot in the first head, which may be comprised of the first front slot.

[0008] In another aspect, a preferred embodiment of the present application is directed to a method for mounting a sludge scraper assembly in a tank having a collector chain with a drive collector chain and a driven collector chain for wastewater treatment. The tank has a tank span width. The sludge scraper assembly includes a first attachment link, a second attachment link and a sludge scraper having a sludge scraper length and a plurality of fasteners exposed from a slot at a rear face of the sludge scraper. The methodincludes cutting the sludge scraper such that the sludge scraper length is less than the tank span width, mounting the first attachment link proximate a first end of the sludge scraper to a first fastener of the plurality of fasteners, mounting the second attachment link proximate a second end of the sludge scraper to a second fastener of the plurality of fasteners, connecting the first attachment link to the drive collector chain and connecting the second attachment link to the driven collector chain.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009] The foregoing summary, as well as the following detailed description of preferred embodiments of the components, hardware and method of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the field configurable sludge scraper and related assembly, there is shown in the drawings a preferred embodiment. It should be understood, however, that the application is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0010] Fig. 1 illustrates a side perspective, partial cutaway view of a prior art sludge scraper system in a wastewater treatment tank wherein walls of the tank are cutaway for clarity;

[0011] Fig. 2 illustrates a side elevational, partially exploded view of components of a sludge scraper assembly in accordance with a preferred embodiment of the present invention;

[0012] Fig. 3 illustrates a side elevational view of the sludge scraper assembly of Fig. 2;

[0013] Fig. 3 Detail A illustrates a magnified side elevational view of a top edge of a first rear slot that opens into a first rear channel of the sludge scraper of the sludge scraper assembly of Fig. 2, taken from within the circle of Fig. 3;

[0014] Fig. 3a illustrates three preferred embodiments of fasteners utilized with the sludge scraper assembly of Fig. 2;

[0015] Fig. 4A illustrates a front elevational view of the sludge scraper assembly of Fig. 3;

[0016] Fig. 4B illustrates a front elevational view of the sludge scraper assembly of Fig. 4 with multiple scraper elements mounted thereto; 30

[0017] Fig. 5 illustrates a side perspective, partially exploded view of the sludge scraper assembly of Fig. 4B, wherein a portion of the assembled sludge scraper is cutaway and a scraper element and related hardware are exploded from the sludge scraper assembly for clarity;

[0018] Fig. 6 illustrates a side perspective view of several sludge scrapers assemblies of Fig. 4B mounted in a wastewater treatment tank on a field configurable chain and flight system in accordance with the preferred embodiment of the present invention, wherein walls of the tank are cutaway for clarity;

[0019] Fig. 7 illustrates a cross-sectional view of the wastewater treatment tank of Fig. 6, taken along line 7-7 of Fig. 6 showing the field configurable chain and flight system of Fig. 6 mounted in the wastewater treatment tank; and

[0020] Fig. 7A illustrates a magnified front elevational view of a portion of the field configurable chain and flight system of Fig. 6, taken from within circle 7A of Fig. 7.DETAILED DESCRIPTION OF THE INVENTION

[0021] Certain terminology is used in the following description for convenience only and is not limiting. Unless specifically set forth herein, the terms “a”, “an” and “the” are not limited to one element but instead should be read as meaning “at least one”. The words "right", "left", "lower," “top,” “bottom” and "upper" designate directions in the drawings to which reference is made. The words "inwardly" or “distally” and "outwardly" or “proximally” refer to directions toward and away from, respectively, the geometric center of the preferred field configurable sludge scraper assembly and related parts thereof. The terminology includes the above-listed words, derivatives thereof and words of similar import.

[0022] It should also be understood that the terms “about,” “approximately,” “generally,” “substantially” and like terms, used herein when referring to a dimension or characteristic of a component of the preferred invention, indicate that the described dimension / characteristic is not a strict boundary or parameter and does not exclude minor variations therefrom that are functionally the same or similar, as would be understood byone having ordinary skill in the art. At a minimum, such references that include a numerical parameter would include variations that, using mathematical and industrial principles accepted in the art (e.g., rounding, measurement or other systematic errors, manufacturing tolerances, etc.), would not vary the least significant digit.

[0023] Referring to Figs. 2-7A, a preferred embodiment of the present invention is directed to a sludge scraper assembly 10 for mounting in a tank 20 having a collector chain for wastewater treatment. The sludge scraper assembly 10 includes a field configurable sludge scraper 12, a carry wear shoe 14, a return wear shoe 16 and an attachment link 18. The sludge scraper 12 is generally considered the main structural element of the sludge scraper assembly 10 with surrounding components affixed to the sludge scraper 12. The sludge scraper 12 includes a first head 32, a second head 34 and a scraper leg 36 connecting the first and second heads 32, 34. The first head 32 includes a channel 32a, 32b, which may include a first front channel 32a and a first rear channel 32b, and the second head 34 includes a channel 34a, 34b, which may include a second front channel 34a and a second rear channel 34b. A slot 32c, 32d, which may include a first front slot 32c and a first rear slot 32d, in the first head 32 preferably provides an opening or window into the channel 32a, 32b in the first head 32, which may include the first front and rear channels 32a, 32b, and the slot 34c, 34d, which may include second front and rear slots 34c, 34d, in the second head 34 preferably provides an opening or window into the channel 34a, 34b, preferably including the second front and rear channels 34a, 34b, respectively. The first and second heads 32, 34 are not limited to including the first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b and may be constructed having single channels that preferably include the first and second front and rear slots 32c, 32d, 34c, 34d for attachment to other components of the sludge scraper assembly 10, as is described in further detail herein. The preferred shape and configuration of the sludge scraper 12 is adapted for constructions using pultrusion of a polymeric material, although the sludge scraper 12 is not limited to being constructed by pultrusion with a polymeric material.

[0024] The carry wear shoe 14 serves as a sacrificial wear element as the sludge scraper 12 is propelled along a lower surface 20a of the tank 20. The return wear shoe 16 serves as a sacrificial wear element as the sludge scraper 12 is propelled along return rails22 that are mounted at sides near a top of the tank 20. The return rails 22 are typically installed at a set distance from the lower surface or the tank floor 20a and near a top surface of the sludge in the tank 20. The attachment links 18 connect the sludge scraper assembly 10 to the collector chains 24 that propel the sludge scrapers 12 and the scraper assemblies 10 through the tank 20. The attachment links 18 are preferably links in the propelling chain that facilitate attachment to the sludge scraper assemblies 10 to the collector chain 24. The carry and return wear shoes 14, 16 and attachment links 18 are preferably connected to the sludge scraper 12 with fasteners 26, which are comprised of threaded track nuts or T-nuts 26 in the preferred embodiment, and associated hardware 28, which are comprised of bolts and washers in the preferred embodiment. The carry and return wear shoes 14, 16 and the attachment links 18 are not limited to being connected to the sludge scraper 12 with the threaded T-nuts 26 and the associated hardware 28 and may be otherwise connected, such as by adhesive bonding, integral molding, clamping, fastening or using other mechanisms and assembly techniques to connect the carry and return wear shoes 14, 16 and the attachment links 18 to the sludge scraper 12. The T-nuts 26 are preferably comprised of an injection molded housing 27a with an integral threaded insert 27b but are not so limited and may be constructed with post-molding threads or may include alternative connection mechanisms. The preferred embodiment of the T-nuts 26 includes single and double T-nuts 26, wherein the single T-nuts 26 include a single threaded insert 27b in the housing 27a and the double T-nuts 26 include two threaded inserts 27b in the housing 27a (See Fig. 3a). The T-nuts 26 are not limited to the single and double T-nuts 26 and may be comprised of T-nuts 26 having additional inserts 27b for connection to the additional hardware 28. The preferred T-nuts 26 may also include variously sized and shaped housings 27a that are designed and configured to slidably fit within the channels 32a, 32b, 34a, 34b and may include a tongue that fits into the slots 32c, 32d, 34c, 34d that facilitate alignment of the T-nuts 26 with the slots 32c, 32d, 34c, 34d. The fasteners 26 may alternatively be comprised of bolts with housings attached to the heads or head portions and threaded shafts extending from the housings (not shown). These alternative bolted fasteners 26 are insertable into the channels 32a, 32b, 34a, 34b with the threaded shafts extending out of the slots 32c, 32d, 34c, 34d for engagement with the associated hardware 28, which may be comprised of nuts and washers.

[0025] The fasteners or T-nuts 26 are preferably positionable in channels 32a, 32b, 34a, 34b in the sludge scraper 12, allowing for positional adjustment of the fasteners 26 and, therefore, the attachment links 18 and the carry and return wear shoes 14, 16 relative to the sludge scraper 12 until the associated hardware 28 is tightened to the fasteners 26. Once the fasteners 26 and associated hardware 28 are tightened, the attachment links 18 and the carry and return wear shoes 14, 16 are secured or locked into their prescribed position along the sludge scraper 12. A scraper element 30 may also be mounted to the sludge scraper 12 to scrape low-clearance sludge from the concrete floor or lower surface 20a of the tank 20 during use. The sludge scraper assembly 10 does not necessarily include the scraper element 30, but the scraper element 30 may be mounted to the sludge scraper 12 based on designer or customer requirements or preferences to scrape low- clearance sludge. The fasteners 26 may be comprised of bolts that are movably positionable within the channels 32a, 32b, 34a, 34b with the threads or threaded shaft extending out of the channels 32a, 32b, 34a, 34b for connection to the hardware 28, which may be comprised of nuts and washers. The fasteners 26 may further be comprised of clamps, snaps, adhesives or other connection mechanisms that may be positioned within the channels 32a, 32b, 34a, 34b and connected to secure the carry and return wear shoes 14, 16, scraper element 30 or other components to the sludge scraper 12.

[0026] In the preferred embodiment, the return wear shoe 16 is removably mountable to the second head 34 or the inner head and the carry wear shoe 14 is removably mountable to the first head 32 or the outer head. The return wear shoe 16 and the carry wear shoe 14 are preferably removably mountable to the first and second heads 32, 34, respectively, using the fasteners 26 and the associated hardware 28 that extend through the first and second front slots 32c, 34c, respectively. The return wear shoe 16 and the carry wear shoe 14 may be shifted along the sludge scraper length L by loosening the fasteners 26 and associated hardware 28, sliding the return wear shoe 16 and the carry wear shoe 14 along the first and second front slots 32c, 34c and tightening the fasteners 26 and associated hardware 28 when the return wear shoe 16 and the carry wear shoe 14 are positioned at the desired location. This adaptability of the return wear shoe 16 and the carry wear shoe 14 facilitates different sized tanks 20 and variable field conditions so thatthe sizing of the sludge scraper 12 and positioning of the return wear shoe 14 and the carry wear shoe 14 may be modified for field conditions.

[0027] The scraper element 30 is preferably removably mountable to the first head 32 or the outer head proximate the scraper leg 36 or the front face of the sludge scraper 12. The scraper element 30 is preferably movably or adjustably mountable to the sludge scraper 12 by the fasteners 26 and the associated hardware 28 that extend through the first front slot 32c. The plurality of fasteners 26, preferably T-nuts 26, are movably positioned within the first front channel 32a to secure the scraper element 30 to the first head 32 using the associated hardware 28. The first front slot 32c preferably extends from the first end 12a to the second end 12b and opens into the first front channel 32a such that the scraper element 30 may be selectively positioned along the sludge scraper length L and fastened to the first head 32 using the fasteners 26 and the associated hardware 28. In the preferred embodiment, the associated hardware 28, which is comprised of bolts, extends through the first front slot 32c and engages the fasteners 26 to mount the scraper element 30 to the first head 32. The fasteners 26 may alternatively be comprised of bolts or other fasteners and the associated hardware 28 may be comprised of bolts or other fasteners to connect the scraper element 30 to the first head 32. The preferred scraper element or scraper bar 30 may include patterned mounting holes 30a or a plurality of patterned mounting holes 30a that are aligned with the fasteners 26 in the first front channel 32a to secure the scraper element 30 with the associated hardware 28. The patterned mounting hole 30a are not limiting and the scraper element 30 may not include any holes 30a and the holes 30a may be drilled into the scraper element 30 during assembly of the sludge scraper assembly 10 on site at the tank 20.

[0028] The plurality of fasteners 26 is preferably positioned within the second rear channel 34b and includes a first fastener 26a. The first fastener 26a is accessible through the second rear slot 34d such that the additional hardware 28, which is a bolt and washer in the preferred embodiment, may engage the first fastener 26a through the second rear slot 34d. The attachment link 28 is removably mountable to the sludge scraper 12 with the first fastener 26a and is configured for connection to the collector chain 24 to drive the motion of the sludge scraper assembly 10 in the tank 20. The attachment link 18 and first fastener 26a are configured for adjustment, preferably slidably adjustable, along thescraper length L between the first and second ends 12a, 12b. Specifically, once the first fastener 26a is the additional hardware 28 or bolt are engaged with the attachment link 18 and partially tightened, the first fastener, additional hardware 28 and attachment link 18 may be slidably adjusted along the scraper length L by sliding along the second rear slot 34d until the attachment link 18 is positioned at its desired location on the sludge scraper 12. When positioned at the desired location, the first fastener 26a and the additional hardware 28 are tightened to fix the attachment link 18 to the sludge scraper 12. This adjustability allows modification of the sludge scraper assembly 10 to fit within the tank 20 and modification to fit the drive system of the tank 20. The first fastener 26a is not limited to being positioned in the second rear channel 34b and may be positioned in any one of the channels 32a, 32b, 34a, 34b, as the first fastener 26a is only used for reference when describing connection of the attachment link 18 to the sludge scraper 12. A second fastener 26b is movably positioned within the first rear channel 32b and similarly engages the additional hardware or bolt 28 and the attachment link 18 to adjustably connect the attachment link 18 to the sludge scraper 12. The sludge scraper assembly 10 preferably includes two attachment links 18 (See Figs. 4A, 4B and 6) that connect the sludge scraper assembly 10 to the collector chain 24 at the drive side and driven side collector chains 24a, 24b. The attachment links 18 preferably act as links in the drive and driven side collector chains 24a, 24b such that the sludge scraper assemblies 10 move through the tank 20 as the collector chain 24 rotates in the tank 20. The attachment link 18 is not limited to being mounted to the rear of the sludge scraper 12 and may alternatively be connected to the front of the sludge scraper 12 to pull the sludge scraper 12 through the tank 20, as would be understood by one having ordinary skill in the art based on a review of the present disclosure.

[0029] The channels 32a, 32b, 34a, 34b are preferably designed and configured to receive the fasteners 26 therein during assembly such that the fasteners 26 may be releasably engaged by the associated hardware 28 through the slots 32c, 32d, 34c, 34d. The fasteners 26 may be comprised of the T-nuts with the associated hardware 28 comprised of the bolts that extend through the slots 32c, 32d, 34c, 34d or the fasteners 26 may be comprised of bolts that extend through the slots 32c, 32d, 34c, 34d and the associated hardware 28 may be comprised of bolts that engage the fasteners 26.

[0030] In the preferred embodiment, the fasteners 26 are comprised of the track nuts or T-nuts 26 with threaded inserts 27b and molded housings 27a. The fasteners 26 may include single inserts 27b or double inserts 27b for connection to the complementary hardware 28, which is comprised of the bolts and washers in the preferred embodiment. The molded housings 27a are preferably designed and configured to slide with in the channels 32a, 32b, 34a, 34b for positioning in the channels 32a, 32b, 34a, 34b with the inserts 27b aligned with the slots 32c, 32d, 34c, 34d such that the complementary hardware 28 may extend through the slots 32c, 32d, 34c, 34d and engagement with the inserts 27b. The fasteners 26 and complementary hardware 28 are preferably delivered to the site of the tank 20 and assembled before installation into the tank 20, although the fasteners 26 may be pre-assembled into the channels 32a, 32b, 34a, 34b.

[0031] The sludge scraper 12 has a scraper length L, a first head 32, a second head 34 and a scraper leg 36 connecting the first head 32 to the second head 34. The scraper leg 36 is positioned at a front of the sludge scraper 12 in the preferred embodiment to push sludge as the sludge scraper 12 is driven through the tank 20 during operation, along with the first head 32 and the second head 34. The scraper leg 36 is not limited to being positioned at the front of the sludge scraper 12 and may be otherwise positioned to connect the first and second heads 32, 34, such as mid-way along a depth of the first and second heads 32, 34, oriented at an angle relative to the first and second heads 32, 34 or otherwise arranged to connect the first and second heads 32, 34 for pushing sludge as the sludge scraper 12 moves within the tank. 20. The scraper leg 36 is preferably positioned at a front of the sludge scraper 12 to define a relatively flat or planar front face of the sludge scraper 12 along with front faces of the first and second heads 32, 34 for pushing sludge and to provide for mounting components of the sludge scraper assembly 10.

[0032] The first head 32 of the sludge scraper 12 includes a first front channel 32a and a first rear channel 32b and the second head 34 includes a second front channel 34a and a second rear channel 34b. The first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b are preferably, generally rectangular channels that extend along the sludge scraper length L and accommodate the fasteners or T-nuts 26 therein. The first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b are not limited to having the generally rectangular shape or to extending alongthe full sludge scraper length L and may be otherwise sized and shaped to accommodate the fasteners or T-nuts 26 therein, preferably such that the fasteners or T-nuts 26 are movable within the first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b for variable mounting of the components of the sludge scraper assembly 10 to the sludge scraper 12. The fasteners or T-nuts 26 are not limited to being movable or adjustable within the first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b and may be fixed within the channels 32a, 32b, 34a, 34b or may be partially secured therein for limited adjustment. The channels 32a, 32b, 34a, 34b are preferably generally open to limit the weight of the sludge scraper 12 but are not so limited and may be relatively solid and encompassing or encasing the fasteners or T- nuts 26 in the material of the sludge scraper 12, which is preferably a polymeric material, wherein the fasteners or T-nuts 26 may be integrally molded within the channels 32a, 32b, 34a, 34b.

[0033] The first head 32 preferably includes a first front slot 32c opening into the first front channel 32a and a first rear slot 32d opening into the first rear channel 32b. The second head 34 preferably includes a second front slot 34c opening into the second front channel 34a and a second rear slot 34d opening into the second rear channel 34b. The first front and rear slots 32c, 32d and the second front and rear slots 34c, 34d preferably extend along the sludge scraper length L but are not limited to extending along the full sludge scraper length L and may extend along only a portion of the scraper length L or may be comprised of various portions that are interrupted along the scraper length L to accommodate the fasteners or T-nuts 26 and, specifically, exposure of the fasteners or T- nuts 26 for connection to additional hardware of the sludge scraper assembly 10. The first front and rear slots 32c, 32d and the second front and rear slots 34c, 34d are configured to act as relatively narrow openings or windows into the first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b, respectively, to gain access to the fasteners or T-nuts 26 that are within the channels 32a, 32b, 34a, 34b. The slots 32c, 32d, 34c, 34d are not limited to being comprised of long narrow apertures or slits that extend along the entire sludge scraper length L but may be comprised of nearly any opening or window that exposes the fasteners or T-nuts 26 that are within the channels 32a, 32b, 34a, 34b for connection to another fastening component. The first head 32 may further includea scraper lip (not shown) that is integrally formed with the first head 32 and extends from a front edge of the first head 32 proximate a leading corner of the first front channel 32a. The scraper lip is designed to optimize cleaning of the floor of the tank 20 during use.

[0034] The sludge scraper 12 preferably has a first end 12a and a second end 12b with the scraper length L measured between the first and second ends 12a, 12b. The channels 32a, 32b, 34a, 34b and slots 32c, 32c, 34c, 34d preferably extend across the full scraper length L from the first end 12a to the second end 12b but are not so limited. The channels 32a, 32b, 34a, 34b and slots 32c, 32c, 34c, 34d may extend only partially along the scraper length L, discontinuously along the scraper length L or otherwise to accommodate the fasteners or T-nuts 26 for connection of components of the sludge scraper assembly 10 to the sludge scraper 12. The channels 32a, 32b, 34a, 34b and slots 32c, 32c, 34c, 34d preferably extend across the full scraper length L to accommodate maximum flexibility for connection points to the fasteners or T-nuts 26 and may include internal or edge stops to prevent the fasteners or T-nuts 26 from moving a predetermined distance along the scraper length L or from falling out of the channels 32a, 32b, 34a, 34b at the first and second ends 12a, 12b. In addition, the fasteners or T-nuts 26 may be fixed at predetermined locations along the scraper length L within the channels 32a, 32b, 34a, 34b based on designer preferences.

[0035] The preferred sludge scraper 12 also includes a first membrane 38 that separates the first front and rear channels 32a, 32b and a second membrane 40 that separates the second front and rear channels 34a, 34b. The first and second membranes 38, 40 preferably extend generally parallel to the scraper leg 36, extend from the first end 12a to the second end 12b and provide strength and stiffness for the sludge scraper 12. The first and second membranes 38, 40 are not limited to extending generally parallel to the scraper leg 36 and may be otherwise designed and configured to provide strength and stiffness to the sludge scraper 12. The first and second membranes 38, 40 may also be used to support the fasteners or T-nuts 26 within the channels 32a, 32b, 34a, 34b, although they are not so utilized in the preferred embodiment.

[0036] The channels 32a, 32b, 34a, 34b preferably each include a plurality of fasteners or T-nuts 26 therein facing out of the slots 32c, 32d, 34c, 34d for selectiveengagement with the associated hardware 28, which is comprised of bolts and washers in the preferred embodiment.

[0037] The threaded T-nuts 26, in combination with the cross-sectional shape of the sludge scraper 12, including the channels 32a, 32b, 34a, 34b, comprise a scraper assembly 10 that can be shipped as a kit, along with the carry and return wear shoes 14, 16, the attachment links 18 and the associated hardware 28, and field adjusted for installation. The field adjustable nature of the preferred sludge scraper assembly 10 is not seen in prior art sludge scraper systems and assemblies, such as C-channel sludge scrapers and derivatives of C-channel sludge scrapers. A C-channel scraper and its derivatives must be predesigned, customized, and machined to accommodate specific attachment link and return shoe positions as outlined by typical dimensions that are utilized to design the scraper based on dimensions of the tank 20, including the tank width WT. The typical dimensions used to design the sludge scraper 12 include a centerline CL or distance between the lateral centers of the first and second attachment links 18, end to centerline ECL or distance between the lateral centers of the attachment links 18 to the first and second ends 12a, 12b, respectively and first and second attachment link spacing RSI, RS2 or spacing between lateral centers of the first and second attachment links 18 to the lateral centers of the first and second return wear shoes 16, respectively, as is shown in Fig. 4A. Machining holes through the prior art C-channel sludge scrapers to locate components is costly if done in a machining facility and timeconsuming if done in the field. In contrast, the configurable sludge scraper assembly 10 can be shipped as an adjustable kit, with no prior customization needed. The attachment links 18 and carry and return wear shoes 14, 16 are located to their desired position along the sludge scraper 12 (See Figs. 4A and 4B), and the correct scraper length of the flight “L” or sludge scraper 12 is produced by measuring and cutting the sludge scraper 12 to the appropriate sludge scraper length L to fit into a tank span width W2 of the tank. The adjustability of the sludge scraper assembly 10 is configured to accommodate last minute adjustments in the field without re-machining hole locations along the sludge scraper 12.

[0038] If scraper elements 30 are added to the sludge scraper assembly 10, the scraper elements 30 may be cut into first, second and third scraper element portions 30b, 30c, 30d having first, second and third scraper lengths SB1, SB2, SB3. The first, secondand third scraper element portions 30b, 30c, 30d are preferably mounted to the flight or sludge scraper 12 using additional fasteners or threaded T-nuts 26, although the first, second and third scraper element portions 30b, 30c, 30d of the scraper element 30 may be otherwise attached to the sludge scraper assembly 10 such as by adhesive bonding, clamping or other attachment or connection mechanisms or methods. The first scraper length SB 1 is preferably a distance from and first end 12a of the sludge scraper 12 to an outside edge of a first carry shoe 14, the second scraper length SB2 is preferably a distance between inside edges of first and second carry shoes 14 along the sludge scraper 12 and the third scraper length SB3 is preferably a distance from an outside edge of the second carry shoe 14 to the second end 12b of the sludge scraper 12. The first scraper element portion 30b is positioned proximate the first end 12a, the third scraper element portion 30d is positioned proximate the second end 12b and the second scraper element portion 30c is positioned between the first and third scraper element portions 30b, 30d and the first and second carry shoes 14.

[0039] The field-configurable sludge scraper assembly 10 offers several advantages when compared to prior art sludge scraper assemblies. As a non-limiting example, the field configurable sludge scraper assembly 10 minimizes labor from a fabrication shop, only requiring a cut to the sludge scraper length L of the sludge scraper 12 in the field to accommodate the tank span width W2. The field-configurable sludge scraper assembly 10 is less expensive to manipulate with its standardized materials on-site compared to prior art sludge scraper assemblies with their customized materials constructed in a fabrication shop before shipping. The design process is also simplified. Instead of making a separate technical drawing for the manufacture of each custom-made part, which is required with the prior art C-channel sludge scraper assemblies, drawings can be made for only a few parts that apply to a wide range of tank span widths W2. Replacing customized parts with standardized parts simplifies inventory and reduces the time from order acquisition to shipping the preferred field-configurable sludge scraper assembly 10 to the job site.

[0040] The sludge scraper 12 and several of the related components of the fieldconfiguration sludge scraper assembly 10 are preferably constructed of a polymeric material, which may be comprised of an engineered composite material such as fiber-reinforced plastics (“FRP”). The fiber-reinforced plastic may be comprised of carbon, glass or aramid FRP materials that are relatively light-weight, corrosion resistant, strong and resilient. Prior art sludge scraper assemblies may be constructed from extruded aluminum, which presents shortcomings when compared to the preferred polymeric and FRP materials used with the field-configurable sludge scraper assembly 10. The polymeric material is not limited to being comprised of FRP and may be comprised of a single component polymeric material or a mix of polymeric materials such that the properties of the components of the field-configurable sludge scraper assembly 10 may be fashioned by the designer, as desired.

[0041] The preferred sludge scraper 12 is preferably constructed of a pultruded FRP material having relatively thin walls and forgiving corner radii rc. The walls preferably have a wall thickness tw of approximately one-sixteenth to five-sixteenths inches (1 / 16- 5 / 16”) or one and six tenths to seven and nine tenths millimeters (1.6-7.9 mm) and the corners preferably have a comer radius rcof approximately one-sixteenth to five- sixteenths inches (1 / 16-5 / 16”) or one and six tenths to seven and nine millimeters (1.6- 7.9 mm). The sludge scraper 12 is not limited to having the described wall thickness tw or the comer radius rc, but these dimensions are preferred such that the sludge scraper 12 is manufacturable using the pultrusion process. In addition, the sludge scraper 12 is not limited to being constructed of a pultruded shape and may be otherwise designed and configured, such as by machined aluminum, three-dimensional printing a polymeric material, injection molding a polymeric material or other techniques and materials. The preferred pultruded FRP sludge scraper 12 is relatively strong and stiff, corrosion resistant and lightweight for use in the wastewater environment. The preferred sludge scraper 12 is strong in the longitudinal direction to resist loads when moving sludge, including pushing or pulling sludge, along the bottom of the tank 20, resists sagging of the sludge scraper 12 when moving along the surface of the wastewater in the tank 20 and is lightweight to reduce the load on the propulsion system of the tank 20 so that the power is focused on moving the sludge and wastewater, instead of driving the heavy prior art metallic flights or scrapers. The preferred polymeric sludge scraper 12 may also be semi-buoyant or buoyant to further reduce the load on the propulsion system of the tank 20 during use. In addition, the pultrusion process is particularly suited to producing therelatively consistent cross-sectional shape of the sludge scraper 12 with first and second heads 32, 34 having the first front and rear channels 32a, 32b and the second front and rear channels 34a, 34b into which the fasteners 26 may be inserted and slide within to facilitate the adaptability of the sludge scraper assembly 10.

[0042] Aluminum can corrode over time in process environments found in the water and wastewater tanks 20. An aluminum scraper is susceptible to galvanic corrosion when pairing or encountering various steel chain options found in the market. In addition, even a light-weight metal such as aluminum presents a significant mass when compared to the field-configurable sludge scraper assembly 10 constructed of the FRP materials. A higher rotating mechanical equipment weight when submerged due to the higher density of the metallic flights results in a lower ability to move sludge without enlarging other mechanical elements of the system. A scraper made from an isotropic metal can only be strengthened by thickening areas of the cross-section or by using a superior grade of material. In contrast, the material choice for the sludge scraper 12 and components of the field-configurable sludge scraper assembly 10 is preferably the polymeric material or engineered composite. Engineered composites offer customization by influencing the density of glass fibers, other strengthening fibers or other components in certain areas of the cross-section to provide higher rigidity across the horizontal plane for the pushing sludge loads. Polymeric materials and engineered composites typically have a significantly lower mass than metals and, therefore, present less of a rotating mechanical load. Polymeric materials and engineered composites typically offer better corrosion resistance in the process environments found in water and wastewater tanks 20, and galvanic corrosion is not an issue for polymeric materials or engineered composites when paired with metallic chains or collector chains 24.

[0043] The preferred material choice of the polymeric materials or engineered composites of the preferred invention informs several features of the cross-section that set it apart from the prior art industry standard. Extruded cross-sections that exist on the market can have relatively sharp corner radii, particularly where the cross-section interfaces with mounting nuts. These sharp comers concentrate stress at the notch comers of the threaded T-nuts 26 and create a tearing edge with insertable floor wipers. In contrast, the preferred pultrusion process for the preferred sludge scraper 12 produceslarger corner radii to optimize the layout of the roving / mat outer layer around an angle. At a right angle of the cross section, a larger radius has better load transfer from bending moments, resulting in lower localized stresses and reduced risk of cracking during the lifecycle of the sludge scraper 12. At an open end of the cross section, a rounded end contains less material than a square end which saves cost. A rounded end also provides a smoother edge when interfacing with the threaded T-nut 26 or a floor wiper.

[0044] In addition, the preferred polymeric or engineered composite material for the sludge scraper 12 generally provides horizontal symmetry. Many existing scraper designs do not have horizontal symmetry due to a scraper lip on one far edge only. The preferred material choice of a pultruded polymeric material or engineered composite encourages symmetry to reduce warpage of the shape when it has exited the pultrusion tooling. This horizontal symmetry permits a user to rotate the sludge scraper 12 one hundred eighty degrees (180°) if it is subject to permanent sag deformation across the horizontal axis while mounted to the collector chains 24, which provides a vast increase in longevity. When rotated one hundred eighty degrees (180°), the wear shoes 14, return wear shoes 16 and attachment links 18 may be re-mounted or replaced to facilitate this reconfiguration of the field-configurable sludge scraper assembly 10. Specifically, the sludge scraper 12 may be flipped one hundred eighty degrees (180°) at its connection to the attachment links 18 such that any sag or deformation may be counteracted by switching the orientation of the sludge scraper 12 to prolong its useful life.

[0045] The preferred embodiment of the sludge scraper assembly 10 eliminates the customization required with prior art scrapers, such as C-channel scrapers, while improving upon the T-nut design of modular extruded scrapers. Typical C-channel scrapers and their derivatives feature spacer blocks with hardware at predesigned locations along the scraper, which requires customization and raises cost. Existing threaded T-nuts are constructed of machined aluminum which presents shortcomings. An aluminum shape may result in galvanic corrosion when interfacing with stainless steel hardware, which is the industry standard for machinery submerged underwater. The preferred injection molded T-nuts 26 provide a lower cost to the product. The corrosion resistance of the polymeric or engineered composite T-nuts 26 is high with an injection molded plastic, and a preferred brass threaded insert is also corrosion resistant. The use ofbrass threaded inserts in conjunction with stainless steel fasteners decreases the potential of stainless-steel galling and galvanic corrosion while eliminating the need for anti-seize coating compounds. Integrating a metallic threaded insert into an injection molded component during the molding process is a novel concept in the water and wastewater treatment industry. This strategy provides a lower cost than a purely metallic component while providing greater strength and thread integrity compared to a purely non-metallic component.

[0046] Competitor T-nuts in the industry have sharp edges to interface with square ends of an extruded scraper, which increases the potential of a stress concentration in the T-nut. They do not contact inner horizontal members of the scraper cross-section, which narrows the footprint of the attachment point and places it further from the center of gravity of the scraper profile. The T-nuts 26 of the preferred embodiment of the invention contain radii in preferred locations to dissipate contact stresses. The preferred T-nuts 26 extend to the inner horizontal members of the scraper 12, creating more rigidity in the assembly.

[0047] The scraper element 30 of the preferred sludge scraper assembly 10 is also different when compared to similar prior art components. Many prior art sludge scrapers in the industry utilize rubber floor wipers, which present shortcomings. Rubber has a high coefficient of friction with the concrete floor 20a of a water or wastewater tank. Rubber has less rigidity which deforms permanently over time. Rubber has a greater tendency to rip or tear from the prior art sludge scraper if catching an obstacle in the tank. The mounting holes for rubber wipers are typically pre-customized to match the length of a customized scraper. In contrast, the preferred embodiment of the sludge scraper assembly 10 includes the polymeric or engineered composite sludge scraper 12 and the scraper elements 30 with patterned mounting holes 30a along the sludge scraper length L of the scraper elements 30. Patterned mounting holes 30a allow the single scraper element 30 to be cut into multiple lengths in accordance with the first, second and third scraper element lengths SB1, SB2, and SB3, as shown in Figs. 4A and 4B. The complementary patterned mounting holes 30a prolong the service life of the scraper element 30 by allowing extension of the scraper element 30 as it is worn away by the tank surface. Providing the single scraper element 30 to be cut in the field offers a higher degree of standardizationthan is typically seen in the industry. Further, the preferred polymeric, FRP and / or plastic material of the scraper element 30 offers advantages in terms of frictional coefficient as well as increased rigidity and durability compared to prior at systems.

[0048] The field configurable sludge scraper 12 is one element out of several that comprise a field configurable sludge collection system. The system in its preferred configuration may be applied to or mounted within rectangular clarifiers found in municipal and industrial water and wastewater treatment applications. Several components offer adjustability in a longitudinal direction of the sludge scraper 12, which is perpendicular to a wastewater tank longitudinal axis H (Fig. 6) or offer adjustability of a span width W1 or sludge tank width WT in the transverse direction (Fig. 1). The sludge scraper assembly 10 is transversely adjustable or adjustable parallel to the sludge scraper length L to accommodate tanks 20 having differing sludge tank widths WT. Typical component sets for sludge collection systems are pre-engineered and customized in accordance with each tank, offering little to no adjustability after being shipped to the site. In contrast, the combination of several field configurable components including the preferred sludge scraper assembly 10 creates a system that can accommodate a wide variety of different sizes of tanks 20, such as tanks 20 having a single collector chain 24 that drives the sludge scraper assemblies 10 to tanks 20 having three (3) or more collector chains 24.

[0049] In operation or use, the components several sludge scraper assemblies 10 are delivered to the worksite at the tank 20 for connection to the collector chains 24. The components preferably include the sludge scraper 12, the carry and wear shoes 14, 16, attachment links 18, fasteners 26, associated hardware 28 and scraper elements 30, The sludge scraper assemblies 10 are preferably customized to fit with the set-up of the tank 20 based on the dimensions of the tank 20, the drive system for the collector chains 24 and other factors that may be unique to the specific job. The sludge scrapers 12 are preferably delivered such that the sludge scraper length L is greater than the sludge tank width WT and the sludge scrapers 12 may be cut so that the sludge scraper length L fits within the sludge tank width WT or the sludge scraper length L is less than the tank width WT. The sludge scraper length L is typically approximately one to forty feet (1-40 ft) or twelve meters (0.30-12 m) to accommodate sludge tank widths WT that are moderatelylarger than the sludge scraper length L. Preferred positioning of the attachment links 18, the carry and return wear shoes 14, 16 and the scraper elements 30 along the sludge scraper length L is determined and may be marked on the sludge scraper 12. The plurality of fasteners 26 positioned in the channels 32a, 32b, 34a, 34b or loosely connected to the attachment links 18, the carry and return wear shoes 14, 16 and / or the scraper elements 30 to slide these sub-assemblies to their desired locations along the sludge scraper length L, guided by the slots 32c, 32d, 34c, 34d. The fasteners 26 and related components 18, 14, 16, 30 slide from the first or second ends 12a, 12b toward the middle of the sludge scraper 12 to their desired locations and the fasteners 26 and associated hardware 28 are tightened to secure the components 18, 14, 16, 30 to the sludge scraper 12. As a nonlimiting example, a first attachment link 18 may be mounted proximate the first end 12a of the sludge scraper 12 to a first fastener 26 of the plurality of fasteners 26 and a second attachment link 18 may be mounted proximate the second end 12b of the sludge scraper 12 to a second fastener 26 of the plurality of fasteners 26. The first and second attachment links 18 may be further secured to the sludge scraper 12 by third and fourth fasteners 26 and fixed to the sludge scraper 12 by tightening the additional hardware 28. Once assembled, the sludge scraper assembly 10 may be attached to the collector chain 24, which may be comprised of a single chain or two or more chains and mounted in the tank 20. The sludge scraper assembly 10 is preferably connected to the collector chain 24 by connecting the first attachment link 18 to the drive side collector chain 24a and the second attachment link 18 to the driven side collector chain 24b. First and second return wear shoes 16 may be connected to the front face of the sludge scraper 12 between the first attachment link 18 and the first end 12a and the second attachment link 18 and the second end 12b, respectively. The first and second carry wear shoes 14 may be connected to the front face of the sludge scraper 12 proximate the first and second attachment links 18, respectively. The scraper element 30 is preferably connected to the front face of the sludge scraper 12 such that a distal edge of the scraper element 30 extends beyond a top surface of the first head 32 of the sludge scraper 12. The individual sludge scraper assemblies 10 may be further adjusted after mounting in the tank 20 to correct uneven travel, replace worn or damaged components 12, 18, 14, 16, 30 or otherwise based on designer or operator desires or requirements.

[0050] The preferred field-configurable sludge scraper assembly 10 may be incorporated with and assembled in conjunction with the head shaft described in International Patent Application No. PCT / US2018 / 031514 and U.S. Patent No.11,092,189 (“Configurable Head Shaft Patents”), both of which are incorporated herein by reference in their entirety. The head shaft of a chain and flight system serves two primary purposes, including (1) to preserve the alignment of the collector chains 24 and the chain drives on either side of the tank 20 and (2) to transmit torque from a drive side 24a to the driven side 24b of the head shaft. Typical composite head shafts seen in the industry do not offer substantial span adjustability because the telescopic extension of the span is permanently constrained by pre-machined interlock slot locations. Typical head shafts do not offer substantial sprocket adjustment due to drive keys that are locationally constrained by pre-machined slot locations. A configurable head shaft, as described in the Configurable Head Shaft Patents offer overall span adjustability or adjustability of span width W1 by field-cutting and drilling the center tube, which is then constrained by couplings and associated hardware. The head shaft of the Configurable Head Shaft Patents offers significant sprocket centerline adjustability or first and second chain spacing SCL1, SCL2 via an extended drive key on opposing ends of the shaft. Each sprocket is located to the proper position and the associated hardware tightened to affix the sprocket along the drive key.

[0051] Another field configurable component in the system of the Configurable Head Shaft Patents is the stub shaft. The stub shaft is a mounting apparatus that controls the position of a rotating idler sprocket and resists the bending moment of the collector chain 24. Many stub shafts in the industry do not offer substantial sprocket adjustment because their journal length corresponds with one prescribed sprocket position only. Tail shafts and idler shafts seen in the industry offer some sprocket locational adjustment but only accommodate one tank span width W2. The configurable stub shaft offers sprocket centerline adjustability or first and second chain spacing SCL1, SCL2 via an extended journal and associated clamp collars. The sprocket is located to the proper centerline along the stub shaft journal, and the clamp collars tightened to constrain the sprocket in the correct position. The configurable stub shaft in the system of the Configurable HeadShaft Patents automatically offers adjustability to accommodate the tank span width W2 due to being a wall-mounted fixture.

[0052] A further configurable component in the system of the Configurable Head Shaft Patents is the wall bracket. The wall bracket is a fixture which supports the return rail 22, guiding and supporting the sludge scrapers 12 and sludge scraper assemblies 10 that travel a set distance above the lower surface or the tank floor 20a. Many wall brackets in the industry do not allow for adjustability in return rail position or first and second return rail spacing RR1, RR2 because the brackets are not intended to be cut in the field. Formed metal brackets do not usually accommodate a field cutting operation due to their geometry. Plastic and composite brackets often do not have a uniform cross- sectional width which can make cutting them unwieldy and difficult. A configurable wall bracket of the Configurable Head Shaft Patents is designed to be easily cut in the field to accommodate a range of positions and to modify the first and second return rail spacing RR1, RR2 for the return rails 22. The brackets are measured and cut on-site before mounting on the sidewalls of the tank 20 to ensure proper dimensional fitment. The uniform cross-sectional width makes the cutting operation easy to execute. After the cutting operation, a hole is drilled into the bracket to affix the return rail 22 and related hardware.

[0053] An additional configurable component in the system of the Configurable Head Shaft Patents is the return rail 22. As mentioned above, the return rail 22 guides and supports the sludge scrapers 12 and the sludge scraper assemblies 10 that travel a set distance above the tank floor or the lower surface 20a of the tank 20. The far end of each return rail 22 is trimmed to length to prevent interference with system components and drilled in the field to coincide with the supporting wall bracket location. The end corners of the return rail 22 may be additionally trimmed to allow for additional component clearance. The return rail 22, which can be cut to length, offers overall adjustability in accommodating a return rail assembly length LI. Each customer is sent the correct number of return rails 22, and the end pieces are configured as needed to accommodate variations of the return rail assembly length LI.

[0054] A further configurable component in the system of the Configurable Head Shaft Patents is the wear strip. The wear strip is placed on the floor 20a and the returnrails 22, providing a smooth sliding surface for the carry and return wear shoes 14, 16 to travel on or slide across. The wear strip is largely configurable in the same manner as the return rails 22. The wear strips are installed consecutively down the length of the tank 20, with the end piece trimmed to length and drilled at the end mounting point to accommodate various return rail assembly or floor wear strip lengths LI, L2. The wear strips may be affixed in a manner allowing for thermal expansion of the material during use.

[0055] The configurable components mentioned above comprise a system that can accommodate a wide variety of different sizes of tanks 20 found in municipal and industrial water and wastewater treatment applications. The benefits of this standardization include cost reduction, lead time reduction, and greater design flexibility.

[0056] It will be appreciated by those skilled in the art that changes could be made to the embodiment described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiment disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

DEPCT6910 / 02 / 25691. Sludge scraper assembly for attachment in a tank with a collector chain for wastewater treatment. The sludge scraper assembly includes: a sludge scraper of various widths, end one, end two, head one, head two, and a scraper leg connecting head one to head two; a sludge scraper constructed of polymer material; head two with slots extending along the length of the scraper and openings for multiple fasteners positioned within the slots in head two; multiple fasteners including fastener one; fastener one assembly passing through the slots on head two and a removable linkage fastener that attaches to the sludge scraper with fastener one and is designed for connection to the collector chain; and a linkage fastener and fastener one designed for adjustment along the length of the scraper between ends one and two.

2. Sludge scraper assembly of claim 1 in which polymer material is incorporated, consisting of fiber-reinforced plastic.3.The sludge scraper assembly of the Ipplication 1, which includes: a removable reverse wear slab attached to the second head and a removable forward wear slab attached to the first head.

4. The sludge scraper assembly of the Ipplication 1, in which the scraper includes the first and second ends, a slot on the second head integrated with a second rear slot, and a slot on the second head integrated with a second rear slot, a second rear slot extending from the first end to the second end.

5. The sludge scraper assembly of the Ipplication 1, which includes: a removable scraper component attached to the first head, close to the scraper leg. 6.The sludge scraper assembly of claim 5 includes: more than one threaded T-shaped screw ring positioned within one front slot in the first head extending from the first to the second end of the sludge scraper; one front slot extending from the first to the second end and opening into one front slot; a removable scraper component attached to the sludge scraper by scraper component hardware connected to more than one threaded T-shaped screw ring; scraper component hardware extending through one front slot and into more than one threaded T-shaped screw ring to attach the scraper component to the first head.

7. The sludge scraper assembly of claim 6 where more than one fastener is assembled with more than one threaded T-shaped screw ring; more than one threaded T-shaped screw ring relative to the mounting holes patterned in the scraper component. 8.The sludge scraper assembly of claim 1 where the slot in the second head is assembled with the second rear slot and the slot on the second head is assembled with the second rear slot; the first head which includes the second front slot separated from the second rear slot by a second membrane; the first head which includes the first front slot, the first front slot, the first rear slot and the first rear slot; the first front and rear slots separated by the first membrane.

9. The sludge scraper assembly of claim 8 where the first front and rear slots and the second front and rear slots include more than one threaded fastener in them facing away from the first front and rear slots and the second front and rear slots, respectively. 10.Sludge scraper assembly for mounting in tanks with collector chains for wastewater treatment, tanks with a range of widths. The sludge scraper assembly includes: the scraper width, head one, head two, and scraper legs connecting head one to head two; head two with slots extending along the length of the scraper and openings; head one with slots extending along the length of the scraper and openings; a scraper length fabricated for on-site modification to fit the scraper within the range of the tank; a removable linkage fastener for attaching the scraper and fabricated for connection to the collector chain; and multiple fasteners fabricated to attach the scraper to the linkage fasteners. Multiple fasteners are included, including fastener one positioned in a slot in head two and exposed through a slot on head two, and fastener two positioned in a slot in head one and exposed through a slot on head one.11.

12. The sludge scraper assembly of claim 10, in which more than one fastener is assembled with more than one threaded T-shaped screw ring.

13. The sludge scraper assembly of claim 10, in which the slot on the second head is assembled with a second rear slot, and the slot on the second head is assembled with a second rear slot; the second head includes a second front slot that extends along the length of the scraper and opens into the second front slot; the first head has a first front slot that extends along the length of the scraper and opens into the first front slot.

14. The sludge scraper assembly of claim 12, in which the first and second front and rear slots and the second front and rear slots extend from the first end to the second end of the sludge scraper.

15. The sludge scraper assembly of claim 10, in which the sludge scraper and the connecting fittings are constructed of polymer material.The sludge scraper assembly of claim 10 includes: a removable scraper component with one function of the front close slot scraper in the first head, a removable reverse wear secondary with the front close slot in the second head, and a removable transmission wear secondary with the front close slot in the first head. 16.Method for attaching sludge scraper assemblies in tanks with collector chains for wastewater treatment, tanks with a width according to the tank span, sludge scraper assembly including a first attachment link, a second attachment link, and a sludge scraper with a length of sludge scraper and more than one fastener exposed from slots on the back face of the sludge scraper. Assembly method: Cutting the sludge scraper so that the length of the sludge scraper is less than the width according to the tank span; attaching the first attachment link close to the first end of the sludge scraper to the first fastener of more than one fastener; attaching the second attachment link close to the second end of the sludge scraper to the second fastener of more than one fastener; connecting the first attachment link to the collector chain; and connecting the second attachment link to the collector chain.17.

16. Method of Claim 16 incorporating: First reverse wear secondary connection to the front face between the linkage with first attachment and first end; and second reverse wear secondary connection to the front face between the linkage with second attachment and second end.

18. Method of Claim 16 incorporating: First forward wear secondary connection to the front face close to the linkage with first attachment; and second forward wear secondary connection to the front face close to the linkage with second attachment.

19. Method of Claim 16 incorporating: Connection of the scraper component to the front face so that the distal edge of the scraper component extends above the top surface of the sludge scraper.

20. Method of Claim 19 in which the scraper component includes scraper component one, scraper component two and scraper component three; scraper component one positioned close to the first end; scraper component three positioned close to the second end; and scraper component two positioned between scraper components one and three.

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