Mechanized rotary brush cleaner for sedimentation tanks

Abstract

An arrangement for cleaning algae and other debris from the various surfaces within a sedimentation tank includes one or more mechanized rotating scrubbing brushes. In contrast to conventional arrangements that use rectangular, non-mechanized brushes, the rotational brush elements of the present invention are more effective and efficient at removing a larger quantity of material from the various interior wall surfaces (e.g., baffle, weir, spillway, etc.) within the sedimentation tank.

Description

TECHNICAL FIELD

The present invention relates to a cleaning arrangement for a sedimentation tank, such as a water or wastewater treatment tank and, more particularly, to a cleaning device that utilizes a mechanized rotary brush arrangement to effectively remove algae and other debris from various surfaces of the tank.

BACKGROUND OF THE INVENTION

A typical wastewater treatment facility includes clarifiers or settling tanks to accomplish separation of solids from liquid. The settled solids are removed from the bottom of the tank as sludge and the clarified liquid above is discharged into an effluent trough or launder. Tank geometries and configurations vary widely but are most commonly circular with the continuous flow of influent water entering near the center of the tank and the discharge of clarified effluent water occurring near the tank periphery. Effluent troughs and launders are generally equipped with weirs to control the flow of the clarified supernatant. In tanks where surface scum is prevalent, scum baffle plates are often provided adjacent to the weirs and the displaced water is forced to flow under a baffle plate that blocks floating scum. Once over the weir, the water flows in an effluent trough or launder to a discharge pipe and on to the next unit in the treatment process. Ultimately, the clean effluent water is disinfected and made sufficiently safe to discharge into a river or stream.

As is known in the art, the outdoor exposure of the treatment tanks in direct sunlight encourages the unwanted growth of algae. This growth is most prevalent one the baffle, weir, spillway and clean water flow channel areas of the treatment tank. Disadvantageously, algae growth on these members inhibits the flow of clean water from the tank. Further, the algae can be carried in thick masses and high concentrations in the clean water being discharged from the final treatment tank. When this occurs, large concentrations of chlorine are required to kill the algae. Since chlorine is relatively expensive, it is preferred to prevent the buildup of algae.

Removing the algae from the baffle, weir, spillway and clean water flow channel has primarily been accomplished in the past by scrubbing the tank structure by hand with long-handled brushes. Since the final treatment tanks are usually quite large, such a cleaning process becomes considerably tedious and labor-intensive.

One prior art apparatus for improving algae removal is disclosed in U.S. Pat. No. 4,830,748 issued to Ford W. Hall on May 16, 1989. The Hall cleaning apparatus comprises a series of rectangular cleaning brushes that are attached through support arms to a main frame member. The main frame member is attached to a conventional skimmer blade. Since the skimmer blade is designed to slowly revolve, the cleaning brushes will also move around the tank. Thus, instead of a worker manually scrubbing algal growth surfaces with a broom, an automated set of brooms essentially moves around the surfaces of the tank. A self-propelled version of this apparatus (for use in arrangements without a skimmer blade) is the subject of U.S. Pat. No. 4,978,447, issued to Ford W. Hall on Dec. 18, 1990. A remaining problem with both of these arrangements, however, is that the brushes are non-mechanized (i.e., a “static” brush design), and a significant amount of algae and other debris may build up on the brush surfaces, thus lessening the cleaning ability of the system. Moreover, the rectangular brush design is not considered as the most effective cleaning arrangement.

Thus, a need remains in the prior art for a mechanized arrangement for effectively cleaning algae and other debris from water and wastewater treatment tanks.

SUMMARY OF THE INVENTION

The need remaining in the prior art is addressed by the present invention, which relates to a cleaning arrangement for a sedimentation tank, such as a water or wastewater treatment tank and, more particularly, to a cleaning arrangement that utilizes a mechanized rotary brush arrangement (i.e., a “dynamic brush”) to effectively remove algae and other debris from various surfaces of the tank.

In accordance with the present invention, a sedimentation tank cleaning apparatus comprises a single rotary brush or a series of rotary brushes attached to a support arm. Each brush is mechanized (either individually or as a group) to rotate at a speed sufficient to effectively remove algae and other debris from the various surfaces within the tank structure. Different sizes of brushes may be used along various surfaces, as need be. Moreover, different rotation speeds may be used for different brush locations. For example, a faster rotation may be used along the baffle and weir, where a larger amount of algae and debris will collect. More aggressive scrubbing in these areas will serve to prevent a significant amount of algae and debris from crossing the spillway into the launder area.

Other and further embodiments and advantages of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, where like numerals represent like parts in several views:

FIG. 1 contains a partial, cut-away isometric view of an exemplary prior art tank cleaning apparatus;

FIG. 2 contains a partial, cut-away isometric view of an exemplary rotary brush tank cleaning apparatus formed in accordance with the present invention;

FIG. 3 is a cut-away side view of the arrangement of FIG. 2;

FIG. 4 is an enlarged illustration of an exemplary motorized brush for use in the various embodiments of the present invention;

FIG. 5 illustrates an alternative embodiment of the present invention, in a partial, cut-away isometric view; and

FIG. 6 is a cut-away side view of the arrangement of FIG. 5.

DETAILED DESCRIPTION

Prior to describing the improvements in the cleaning of water or wastewater treatment sedimentation tanks in accordance with the present invention, it is considered helpful to review the state-of-the-art cleaning apparatus. In particular, FIG. 1 illustrates an exemplary prior art apparatus 10, including a set of non-mechanized or “static” scrubbing brushes that are used to dislodge algae and other debris from surfaces within the tank. As shown, prior art apparatus 10 includes a main frame member 12 that is attached to a skimmer blade 14 by using a mounting bracket 16. During operation, skimmer blade 14 slowly revolves around the water treatment tank (as indicated by the arrows in FIG. 1) so as to direct any floating debris into a scum trough. In this prior art arrangement, therefore, the scrubbing brushes that are attached to main frame member 12 will revolve in a similar manner.

Water treatment tank 20 (which is nominally circular in form, with only a portion being illustrated in FIG. 1) includes an interior baffle 22 and a weir 24 that function as described above to control the discharge of clarified water exclusive of surface scum. As shown, weir 30 is contiguous with a spillway 26, where spillway 26 is configured to include a downwardly sloping outer wall 28. Ultimately, the fully treated water will flow into outer clean water channel 30 of tank 20.

In operation of prior art apparatus 10, a first set of brushes 32 is provided to scrub/clean baffle 22 and weir 24, including individual brushes to clean the inner surface of baffle 22, the outer surface of baffle 22 and the inside surface of weir 24. A second set of brushes 34 is used to clean the outer surface of weir 24 and spillway 26, including a brush mounted in a sloping position to clean sidewall 28 of spillway 26. Lastly, a third set of brushes is used to scrub clean water channel 30, with separate brushes for the sidewalls and bottom surface of channel 30. As mentioned above, while a degree of improvement is achieved with this prior art apparatus (as compared to manual cleaning processes), various amounts of algae and other debris may be lodged against the static brushes, resulting in ineffective cleaning.

FIGS. 2 and 3 illustrate a first embodiment of the present invention that provides an improvement over prior art apparatus 10 as shown in FIG. 1. In particular, apparatus 40 is formed to include mechanically-driven rotary brushes to more effectively clean the various surfaces within the treatment tank. For the sake of simplicity, the same treatment tank 20 as described above is illustrated in FIG. 2, with the only change being the replacement of prior art apparatus 10 with inventive cleaning apparatus 40 formed in accordance with the present invention. Referring to FIG. 2, cleaning apparatus 40 is illustrated as including a support assembly 42, which extends outward from the center of the tank (not shown) toward clean water channel 30. In the particular embodiment of FIG. 2, assembly 42 includes a first support member 44 for supporting and driving a first plurality of mechanically-driven rotary brushes and a second support member 46 for supporting and driving a second plurality of mechanized rotary brushes.

FIG. 4 contains an isometric view of an exemplary mechanized rotary brush 100 that may be used in the exemplary embodiment of the present invention as illustrated in FIGS. 2 and 3. As shown in FIG. 4, brush 100 comprises a bristle assembly 110 disposed at the termination thereof, with bristle assembly 110 configured to rotate (in this case, in a counterclockwise direction). The rotation of bristle assembly 110 is controlled by a motor 120 mounted directly over and attached to bristle assembly 110. Motor 120 is sized so as to provide the desired amount of torque required to provide the rotational movement. A control signal for motor 120, as well as the electrical, pneumatic or hydraulic power necessary to drive motor 120, are provided as inputs from a remote source (not shown). A handle 130 may be used as a conduit and thereafter coupled to motor 120. In some embodiments of the present invention, the speed of motor 120 is controllable, so as to adjust the rotational speed of bristle assembly 110.

It is to be understood that the inclusion of motor 120 on brush 100 is exemplary only. Various other arrangements may be used that include the provision of a single, centralized motor that is coupled to each separate bristle assembly through an interconnection, such as a pulley system. While more efficient in terms of the reduction of motors and power required, the single-motor embodiment lacks the ability to modify the rotational speed of the individual brushes. However, either arrangement may be used in accordance with the present invention.

With this understanding of the particular brush assembly, it is possible to understand the operation of the present invention by reference to FIGS. 2 and 3. Referring again to FIG. 2, first support member 44 is illustrated as providing power and movement to a first plurality of mechanically-driven rotary brushes including an inner baffle wall cleaning brush 50, an inner weir wall cleaning brush 52, an outer weir wall cleaning brush 54, and a pair of clear water channel floor cleaning brushes 56 and 58. It is to be understood that this particular arrangement and distribution of brushes along first support member 44 is exemplary only, and that virtually any number and arrangement of mechanized brushes may be used. In its simplest form, a single mechanized rotary brush may be used alone or in combination with the “static” brushes of the prior art. The rotary brush or brushes can also be moved manually from one cleaning surface to another. Another embodiment of the present invention (not shown) involves an additional automated mechanism to move the brush or brushes from surface to surface.

In accordance with the present invention, the necessary power and control signals are fed along first support member 44 and into the individual motors 120 of each brush assembly 100. Elements 110, 120 and 130 of an exemplary brush (as discussed above in association with FIG. 4), are particularly referenced in association with brush 56 in FIG. 2. It is to be understood that each individual brush in the arrangement of FIG. 2 contains similar elements.

Second support member 46, as shown in FIG. 2, provides power and movement to a second plurality of mechanized rotary brushes. In this particular embodiment, second support member 46 is shown as coupled to an outer baffle wall cleaning brush 60, a spillway cleaning brush 62, an angled spillway brush 64 and a pair of channel wall cleaning brushes 66 and 68.

The cut-away side view of FIG. 3 clearly illustrates the location of the various individual mechanized rotary brushes with respect to the various surfaces in water treatment tank 20. Particularly evident in this view is the angular placement of brush 64, so as to accommodate the downwardly sloping face 28 of spillway 26. The utilization of the set of brushes 56, 58, 66 and 68 along the surfaces of clear water channel 30 are considered to be more than sufficient to remove any remaining algae and debris that collects in this outermost region. As with the arrangement and disposition of brushes along first support member 44, it is to be understood that the various brushes included along second support member 46 may vary, as need be. Indeed, it is to be understood that various other support arrangements, using fewer or more support arms, may be employed, as long as the entire assembly is capable of rotational motion around the tank while providing rotational energy to the various brushes.

Thus, in accordance with the present invention, the application of electrical, pneumatic or hydraulic power signals along first and second support members 44, 46 energizes the individual motors associated with each of the illustrated rotary brushes. Upon activation, the bristle assembly will rotate at a predetermined speed to provide efficient cleaning. In one embodiment, a common control/power signal is used for the entire combination of brushes. Alternatively, different brushes may be coupled to separate power/control leads so as to separately adjust the rotational speed of each brush and tailor the scrubbing ability of each brush for its particular use (i.e., scrubbing the weir vs. scrubbing the clear water channel).

FIGS. 5 and 6 illustrate an alternative embodiment of the present invention that utilizes an alternative orientation of the brushes, resulting in the use of fewer brushes and requiring only a single support arm. As with the embodiment discussed above, separate motor elements (or a single motor with a pulley arrangement) are used to provide rotational motion to each brush. Referring to FIG. 5, inventive scrubbing arrangement 70 includes a single support arm 72, with a plurality of separate brushing elements disposed along support arm 72. In particular, a first brush 74 is disposed to clean the inner wall of baffle 22. A second brush 76 is disposed to clean both the outer wall of baffle 22 and the inner surface of weir 24, where the scrubbing material of brush 76 is appropriately sized so as to contact both surfaces (see also the cut-away side view of FIG. 6). A third brush 78 is used to clean spillway 26, with an additional brush 80 used to scrub angled surface 28 of spillway 26. Inasmuch as brush 80 is used to clean only one surface, a traditional bristled brush may be used. Lastly, a final brush 82 is disposed within clear water channel 30 and used to clean the bottom surface, as well as the side surfaces, of the channel. Referring to FIGS. 5 and 6, brush 82 is sized such that the bottom surface of brush 82 will scrub the floor of channel 30, with the outer periphery of brush 82 used to scrub the sidewalls of channel 30. As with the embodiment of FIGS. 2 and 3, each brush in scrubbing arrangement 70 may include an individual motor to impart rotational motion to the scrubbing elements. Further, the speeds may be varied (as needed) to control the desired degree of cleaning.

While this invention has been described fully and completely with special emphasis upon preferred embodiments, it should be understood that various modifications and alterations may be made to the particular brush and/or support mechanism and remain within the spirit and scope of the present invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, and fall within the scope of the invention.

Claims

1. An apparatus for cleaning algae and debris from a sedimentation tank including a revolving skimmer and a nominally circular weir, the apparatus comprising:

at least one support means;

at least one rotating brush assembly coupled to the at least one support means, the at least one brush assembly including at least one mechanized rotating brush element that rotates at a predetermined speed as the apparatus revolves around the sedimentation tank.

2. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact an inside surface of the nominally circular weir.

3. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact an outside surface of a scum baffle within the sedimentation tank.

4. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact an inside surface of a scum baffle within the sedimentation tank.

5. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact an inside spillway between the weir and a subsequent effluent trough.

6. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact a wall of a effluent trough.

7. The apparatus as defined in claim 1 wherein at least one rotating brush element is disposed along the associated rotating brush assembly so as to contact the bottom of the effluent trough.

8. The apparatus as defined in claim 1 wherein at least one rotating brush element is removable from the associated rotating brush assembly so as to be moved from one cleaning surface to another.

9. The apparatus as defined in claim 1 wherein the apparatus further comprises at least one non-rotating brush element.

10. The apparatus as defined in claim 1 wherein the apparatus further comprises a mechanical device for moving at least one rotating brush element from one location to another.

11. The apparatus as defined in claim 1 wherein each rotating brush element includes a rotating element such that each brush element is capable of rotating at a different, predetermined speed as the apparatus revolves around the tank.

12. The apparatus as defined in claim 11 wherein each rotating brush element rotates at the same speed.

13. The apparatus as defined in claim 12 wherein the speed of the plurality of rotating brush elements is adjustable.

14. The apparatus as defined in claim 11 wherein each separate rotating brush element is capable of rotating at a different speed.

15. The apparatus as defined in claim 14 wherein the speed of each separate rotating brush element is adjustable.