The present invention relates generally to the field of wastewater treatment systems. More particularly, the invention relates to techniques for supporting aeration systems such that reactor vessels can be easily cleaned and serviced.
In the field of wastewater treatment, a number of different system types are known and are currently in use. In general, these may consist of primary treatment, secondary treatment, and, where desired, tertiary treatment. Primary treatment is often limited to filtering and sludge removal. Secondary treatment may include a wide range of processes, such as biochemical oxygen demand reduction, nitrification, denitrification, and so forth. Following secondary treatment, further settling, filtering, polishing and other operations may be performed before the wastewater is advanced to a final application.
In a number of the processes used for wastewater treatment, particulate matter may be caused to precipitate from the wastewater and collect on the bottom of a vessel. Reactor vessels for secondary treatment, for example, commonly hold a bolus of wastewater in a reactor vessel, along with biological support media. The biological support media may include various shapes and configurations of synthetic plastic elements on which bacteria or other microbes are allowed to grow and through which wastewater can pass. The bacteria proliferate and serve to treat the water in the reactor vessel by circulation of the water over the support media. To promote the growth and sustenance of the microbial growth, moreover, such reactor vessels may have aeration systems that bubble fresh air through the wastewater, feeding the bacteria and causing the media to move so as to adequately circulate the wastewater over the growth.
In known wastewater treatment vessels of this type, it is common to form aeration systems of one or more headers from which distribution conduits extend. Air is provided through the header, and travels through the distribution conduits and out through holes formed in the distribution conduits. The air can thus bubble through the water to aid in mixing the water and moving the biological growth support media. Similar systems may be provided for pulsing air time-to-time for similar purposes. Such aeration systems, however, are commonly supported on the bottom of the reactor vessels. That is, risers and various supports may be provided that raise the header and distribution conduits slightly from the bottom of the vessel. These support systems, however, may preclude cleaning of the reactor vessels. The vessels are, therefore, from time-to-time emptied, and the aeration systems must be removed to access and manually remove sludge, debris, and grit from the bottom of the vessels.
There is a need, however, for improved systems for wastewater reactor vessel maintenance. More particularly, there is a need for techniques that can allow for effective aeration of reactor vessels, while allowing for continuous or periodic cleaning, or at least simplified cleaning on an as-needed basis.
The present invention provides a wastewater treatment reactor aeration support system and method designed to respond to such needs. The system may be installed in any type of wastewater treatment reactor, but is particularly well-suited to reactors in which the aeration system may be lowered and secured in place on supports provided within the reactor. The supports may extend from the reactor wall, and serve to support the entire aeration system at a distance above the vessel floor. A space between the aeration system and the vessel floor, then, is unencumbered. The space may be provided with an automated, or semi-automated cleaning system for the removal of accumulated sludge, debris, grit, and so forth. Alternatively, the bottom region of the vessel between the aeration system and the vessel floor may be unencumbered, and sludge may be easily removed by systems that are passed between the aeration system and the floor from time-to-time.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Turning now to the drawings, and referring first to
As will be appreciated by those skilled in the art, wastewater treatment in vessels of this type may proceed through a range of specific processes, typically with one process being performed in each reactor vessel. For example, a vessel may be provided for biochemical oxygen demand reduction operations (BOD), nitrification operations, denitrification operations, and so forth. In such operations, a biological growth support media, indicated generally by reference numeral 20 in
The reactor vessels 14 and 16 have sidewalls 22 and a bottom 24 that enclose the interior volume in which the wastewater is disposed, along with the biological support media. The reactor vessels may be made of concrete, metal, plastic or any suitable material. The bottom is typically sealed to the sides to form a water-tight recipient that may be open at an upper end. One or more screens, as indicated by reference numeral 26 in
The aeration system 10 within each reactor includes a conduit system 32. As described more fully below, the conduit system may include one or more headers from which distribution tubes extend. Thus, air may be introduced into the wastewater within each reactor through the conduit system. The introduced air bubbles through the water, gradually rising and providing air for promoting the growth of the biological material on the support media. Moreover, the air aids in circulating the water and support media, further promoting the treatment.
As shown in
In the illustrated embodiment, the longitudinal support is affixed to the angle bracket 48 by means of one or more bolts 52. The bolts firmly secure the aeration system to the supports, and prevent movement of the aeration system longitudinally and laterally. Similarly, one or more brackets, bolts, or similar structures serves to secure the conduit system to the longitudinal supports. In the embodiment illustrated in
It should also be noted that other physical support systems may be envisaged to raise the aeration system from the bottom of the reactor vessel. For example, a superstructure may be provided at or near the top of the vessel and the aeration system may be hung from the structure so as to position the aeration system at a desired level within the reactor vessel (spaced from the vessel floor). In such embodiments, the upper support structure may be generally similar to that illustrated, with one or more longitudinal supports, but may also include lateral supports extending between the longitudinal supports. From these, then, elongated suspension rods or hangers may be extended to the conduit system, which itself may or may not include additional support structures.
The elevation of the aeration system 10 above the bottom of the reactor vessels greatly facilitates the free accumulation of silt, sludge, debris, grit, and any other objects that may fall into or collect in the vessel during operation. Moreover, the creation of a free space along the bottom of the reactor vessel allows for such silt, sludge, debris, and grit to be more easily directed towards collection devices, or moved along or extracted by collection systems.
Moreover, while the support structures described above extend from sidewalls of the reactor vessel, or provide support by suspension of the elevated aeration system, other supports may be provided very near or even adjacent to the sidewalls and may extend to the bottom of the reactor vessel. For example, risers or elevators may be positioned adjacent to sidewalls of the vessel, while leaving an open area beneath the overall aeration system structure. The supports may be generally similar to those used in conventional wastewater treatment systems, but with no supports being provided under the portion of the aeration system spaced from the sidewalls any significant degree. Thus, access to and cleaning of silt, sludge, debris, and grit is facilitated greatly as compared to heretofore known systems that include a number of supports or risers distributed along the entire conduit system.
In the embodiment illustrated in
Still further, any silt, sludge, debris, and grit that collects below the elevated aeration system 10 may be removed on a periodic basis by vacuum means.
It should be noted that certain embodiments of the elevated aeration system described above may be more advantageous for certain types and designs of systems. For example, mechanisms for elevating aeration systems that include supports extending from walls of a reactor vessel may be best used in smaller vessels where the spans between side walls are sufficiently short to permit reasonably sized support structures for the air conduits. In a presently contemplated embodiment, for example, such elevated aeration systems may be used with reactor vessels of the type described in U.S. provisional patent application Ser. No. 61/154,211, filed on Feb. 20, 2009, entitled Modular Wastewater Treatment System and Method, which is hereby incorporated herein by reference.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application is a Nonprovisional Patent Application of U.S. Provisional Patent Application No. 61/154,239, entitled “Water Treatment Reactor Aeration Support”, filed Feb. 20, 2009, which is herein incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/24417 | 2/17/2010 | WO | 00 | 10/31/2011 |
Number | Date | Country | |
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61154239 | Feb 2009 | US |