The present inventive concept relates to a system for treating wastewater, especially wastewater from electronics and semiconductor fabrication facilities, but inclusive of other facility types.
Electronics, semiconductor companies, and many other enterprises use acid waste neutralization systems (AWN) to treat millions of gallons of wastewater that may flow from their fabrication facilities every day. Substantially non-particulate wastewater is deionized. The pH of this wastewater can have a wide range from high to low. By regulation, the pH for discharge must be about 7.0.
A conventional wastewater treatment system for acid waste neutralization has two to three reactor tank assemblies in series which will have a wastewater retention time during treatment of 30 minutes to 90 minutes. These reactor tank assemblies may hold more than one hundred thousand gallons of wastewater and handle flows typically between 1,000 to 10,000 gallons per minute (GPM). Further, these reactor tank assemblies have mixers mounted on the top and acid and caustic conveyance systems to neutralize the water to an acceptable band straddling 7.0 pH.
Saving space is important in fabrication facilities where production is environmentally controlled and creating new space can be difficult. Conventional systems have several disadvantages. 1) The size of a system of wastewater treatment reactor tank assemblies able to handle 2,500 GPM is about 30 feet wide, 100 feet long, and 30 to 50 feet tall. This footprint involves more than one reactor, each reactor having a radius of about 15 feet. 2) The wastewater treatment systems are built on-site because many of the components, if preassembled, are too big to carry over most roadways. Onsight production drives up costs, and production time is higher than might be achieved using shop fabrication efficiencies. 3) Reactor tank assemblies typically operate at 100% capacity. There is no flow equalization, which means the system is limited to and must be able to handle the peak flow being fed from the fabrication facility. 4) The whole wastewater treatment system is designed to use gravity to power outflow, which requires ensuring all conveyances are designed such that gravity feeds the system inflow and outflow. 5) With the wastewater treatment system already being designed to handle peak flows expected from each given fabrication facility during installation, expanding a fabrication facility can prove difficult because of the need to increase the capacity of the existing wastewater treatment system and the need to address what may be limited sewer capacity and a limited available installation footprint for expanding the wastewater treatment system.
Therefore, there is a need in the market for an improved wastewater treatment system for electronics and semiconductor fabrication facilities that eases the ability to expand water treatment capacity and lowers both the footprint of equipment and the water pressure required to convey wastewater through the system.
Disclosed is a wastewater treatment system and method for electronics and semiconductor fabrication facilities designed, in one embodiment—through time-efficient kinetics that reduce wastewater retention in the system from 10 to 30 minutes to 5 to 15 minutes—to reduce the footprint from 25 feet by 100 feet for a conventional wastewater treatment system to about 25 feet by 25 feet for the disclosed wastewater treatment system. Comparable reductions may take place for other embodiments of different sizes. The shorter wastewater retention time for the representative embodiment reduces the footprint of a 2,500 GPM system to 25 by 25 feet for a single train reactor tank assembly system or 25 by 50 feet for a two-train reactor tank assembly system.
In one embodiment of the disclosed wastewater treatment system, the reactors are designed to have a buffer zone suitable for holding variable wastewater levels. This means fabrication facilities can use smaller reactors, level controls, and variable speed circulation pump assemblies to manage the wastewater treatment process and accommodate varied wastewater flows.
In one embodiment of the disclosed wastewater treatment system, at least one circulation pump assembly is used to mix and recycle wastewater while the system adjusts for pH levels that are higher or lower than permitted pH levels for discharging. Mixing assemblies in some embodiments include rotary mixers having at least one blade. Mixing, in some embodiments, is conducted or further conducted by reactor tank assembly eductor mixers disposed at the bottom of each reactor tank assembly. Mixing eductors, where present, are further used to leverage pressure and water flow. In one embodiment, 2 to 10 mixing eductors increase wastewater mixing beyond the circulation produced by circulation pump assemblies alone. Therefore, in these embodiments, water flows are created without requiring mechanical—propeller-based—mixers.
Embodiments of the disclosed wastewater treatment system are designed to be compact enough to allow prefabricated systems to be shipped by truck over a typical roadway. As such, the disclosed wastewater treatment system may be produced by way of pre-engineered and prepackaged modules and may be constructed in parallel with preparing the installation site at the receiving electronics and semiconductor fabrication facility.
Embodiments of the disclosed wastewater treatment system forgo depending on gravity to move wastewater in favor of pumping wastewater through the lines of a pipe system. Flows can be increased over existing piping by increasing water flow pressure.
Embodiments of the disclosed wastewater treatment system afford modularity and associated expandability. In addition, installing parallel trains of reactor systems as needed can also ease system expansion when compared to conventional, gravity-based systems of similar capacity.
Embodiments of the disclosed wastewater treatment system are designed to be operationally flexible by having capacity buffers designed to handle and manage variable wastewater flows. Multiple reactor tank assemblies of the disclosed wastewater treatment system may be installed in series for fine-tuning wastewater output, or multiple reactor tank assemblies may be installed in parallel, allowing flows to substantially double over a single reactor tank assembly system for each parallel installation of a reactor tank assembly. Multiple reactor tank assembly trains correspondingly increase available wastewater flow capacities. In one embodiment of the wastewater system, wastewater treatment flows may be set as required to flow through multiple reactor tank assembly trains either or both sequentially and in parallel, with a flow variability from about 2,500 GPM to 10,000 GPM.
One embodiment of the system for treating wastewater has at least one reactor tank assembly. The at least one reactor tank assembly is operable at least one or more of singly, as a series of reactor tank assemblies, and parallel with other reactor tank assemblies. At least one inflow pipe and valve assembly is coupled to the at least one reactor tank assembly and is designed to direct wastewater into the at least one reactor tank assembly through at least one inlet header port assembly disposed on a top portion of the reactor tank assembly. At least one outflow pipe and valve assembly is coupled by at least one outlet port assembly of the at least one reactor tank assembly and is designed to direct wastewater out from the at least one reactor tank assembly. At least one return flow pipe and valve assembly of the at least one outflow pipe and valve assembly is designed to direct, as required, at least a portion of the wastewater flowing out from the at least one reactor tank assembly back into the at least one reactor tank assembly.
In this embodiment of the system for treating wastewater, the at least one circulation pump assembly is disposed on the at least one outflow pipe and valve assembly. There is, in this embodiment, at least one carrier-injector pump assembly. The at least one carrier-injector pump assembly is designed to pump a portion of—in one embodiment this being between about 10 to 50 GPS—of the wastewater fed to it as a secondary stream of wastewater flowing through the at least one outflow pipe and valve assembly.
In one embodiment of the system for treating wastewater, the eductor mixer assembly is operationally disposed on a bottom portion of the at least one reactor tank assembly and is designed to mix wastewater in the reactor tank assembly, inclusive, when present, of wastewater drawn from the reactor tank assembly and reintroduced into the reactor tank assembly through the at least one return flow pipe and valve assembly.
In one embodiment of the system for treating wastewater, at least one pH sensor assembly is disposed at least partially within the wastewater flow and is operationally coupled to at least one computer system, the at least one computer system is designed to control introducing at least one or more of acid from an at least one acid storage reactor tank and valve assembly operationally coupled to the wastewater flow and a caustic from an at least one caustic storage reactor tank and valve assembly operationally coupled to the wastewater flow, the at least one or more acid and caustic used to treat the wastewater by changing the pH of the wastewater. The at least one or more acid and caustic is introduced to the wastewater as the wastewater flows through one or more streams of the outflow pipe and valve assembly until, through one or more treatments, the wastewater is suitable for discharge.
In one embodiment of the system for treating wastewater, at least one static mixer is disposed on the outflow pipe and valve assembly, and at least one pH sensor is disposed on the outflow pipe and valve assembly following the static mixer. The at least one pH sensor is designed to test wastewater pH after the wastewater has passed through the static mixer, wherein if the pH is inclusively between 5.0 and 8.0, a selector valve assembly opens and allows the wastewater to flow out of the system for treating wastewater and to a sewer system. If the pH is less than 5.0 or greater than 8.0, the selector valve assembly closes and directs wastewater to flow back into the reactor tank of origin.
The inventive concept now will be described more fully hereinafter with reference to the accompanying drawings, which are intended to be read in conjunction with both this summary, the detailed description, and any preferred and/or particular embodiments specifically discussed or otherwise disclosed. This inventive concept may however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of illustration only and so that this disclosure will be thorough, complete, and will fully convey the full scope of the inventive concept to those skilled in the art.
Following are more detailed descriptions of various related concepts related to, and embodiments of, methods and apparatus according to the present disclosure. It should be appreciated that various aspects of the subject matter introduced above and discussed in greater detail below may be implemented in numerous ways, as the subject matter is not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.
DI water, but may include other types of wastewater from fabrication facilities, DI which is water purified to remove substantially all mineral ions such as cations like sodium, calcium, iron, and copper, and anions such as chloride and sulfate. The characterization of these streams and associated pH varies from acidic at 0.50 pH to basic at over 10.0 pH.
If necessary, the wastewater treatment system may operate with a single reactor tank assembly 100, at which point wastewater from the single reactor tank assembly 100 is routed to a sewer or other depository without going through another reactor tank assembly 100. Off-spec return flows to the respective reactor tank assembly 100, in the representative embodiment, is used when one reactor tank assembly 100 is in service and if treated water pH exiting the static mixer 13 does not meet pH specifications.
Wastewater in the representative embodiment, often originating as Ultra-Pure Water (UPW), is delivered to the reactor tank assemblies 100 in separate lines as represented by lines 1, 2, 3, 4 . . . N. The system for treating wastewater from electronics or semiconductor fabrication facilities may be termed Acid Waste Neutralizers or AWN, given the prevalence of acids used at such facilities. Multiple duplex trains of reactor tank assemblies 100 can be added in parallel to expand inlet flow capacity, as illustrated in
Various related embodiments of the inventive concept are also described in the drawings filed and labeled Appendix A, which is incorporated herein by reference in its entirety. The following patents are incorporated by reference in their entirety: Pat. Nos. US2018/0162743, U.S. Pat. Nos. 9,884,348, 7,972,507, 3,395,799, CN209721777, CN109553148, KR100500374, KR20030076009, JP2003148400, CN1094469, and JP55018274.
While the inventive concept has been described above in terms of specific embodiments, it is to be understood that the inventive concept is not limited to these disclosed embodiments. Upon reading the teachings of this disclosure, many modifications and other embodiments of the inventive concept will come to mind of those skilled in the art to which this inventive concept pertains, and which are intended to be and are covered by both this disclosure and the appended claims. It is indeed intended that the scope of the inventive concept should be determined by proper interpretation and construction of the appended claims and their legal equivalents, as understood by those of skill in the art relying upon the disclosure in this specification and the attached drawings.
This application claims priority to and the benefit of U.S. application Ser. No. 18/304,961 titled SYSTEM FOR TREATING WASTEWATER FROM ELECTRONICS AND SEMICONDUCTOR FABRICATION FACILITIES filed on Apr. 21, 2023, which claims benefit of Provisional U.S. application 63363414 titled SYSTEM FOR TREATING WASTEWATER FROM ELECTRONICS AND SEMICONDUCTOR FABRICATION FACILITIES filed on Apr. 22, 2022, which are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 63363414 | Apr 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18304961 | Apr 2023 | US |
| Child | 18528167 | US |