Patent Application
20110036783
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This invention relates to the field of Combined Sewer Systems. Throughout this application, the term “water” will refer to matter flowing through any of the systems described herein. The flowing matter includes water and a variety of other liquid and solid materials.
In a Combined Sewer System, rainwater and sewage are combined into a single flow. The water from the Combined Sewer System ordinarily passes through a sewage-treatment plant before the treated water is discharged into a body of water. However, rain often falls at a rate such that the combined flow of sewage and rainwater exceeds the capacity of the sewage-treatment plant or the capacity of the sewer lines leading to the sewage-treatment plant. When such a rain occurs, a combination of rainwater and sewage is discharged without undergoing full treatment. The discharge occurs through a Combined Sewer Overflow (“CSO”). Operators of Combined Sewer Systems want to decrease the frequency and the volume of untreated discharges occurring through CSOs.
The inventor has conceived a system that reduces discharges through a CSO by controlling the flow of rainwater from individual buildings (or other sources of rainwater) into the Combined Sewer System. The system accomplishes this goal by capturing rainwater that otherwise would be combined with sewage and cause a discharge from the CSO and holding it until discharging it will not cause the combined water flow in the Combined Sewer System to exceed the capacity of the sewage-treatment plant or the capacity of the sewer lines leading to the plant.
The invention is best understood from the following detailed description when read with the accompanying drawings.
Described herein is an exemplary embodiment of a system 100 according to the invention for controlling discharges of untreated water from a Combined Sewer System. The Combined Sewer System carries rainwater and sewage from a drainage basin and has a Combined Sewer Overflow (“CSO”) for discharging untreated material. As shown in
In the exemplary embodiment, system 100 further comprises detector 30, which receives data that is either a direct measure of, or correlate to, a discharge from the CSO. In various embodiments, detector 30 may receive the data in any of numerous ways, including measurement by the detector itself of fluid levels or flows within the combined sewer distribution system, at the sewage treatment plant, using rain gauges to measure the volume and/or intensity of a rain “event,” or receiving rain data gathered by others. System 100 further comprises transmitter 40 for remotely controlling the control valve. In the exemplary embodiment, transmitter 40 may take the form of a radio transmitter in communication with receiver 58 in communication to receive a signal to open or close the control valve 56. Transmitter 40 may take the form of any other type of remote communication device, including but not limited to devices sending signals over telephone wires, internet-based systems, or cellular telephone systems. In certain embodiments, system 100 further comprises controller 70 in operative communication with detector 30 and transmitter 40 so that controller 30 may receive data from detector 30, process the data, and then cause transmitter 40 to make an appropriate transmission to open or close the control valve 56. Alternatively, in certain embodiments controller 70 may be omitted, and detector 30 may communicate directly with transmitter 40. Processing the data might include determining that control valve 56 should be closed when rainfall exceeds a certain threshold in a certain length of time. In the embodiment shown, controller 70 may be a general-purpose computer programmed to receive data from detector 30, process it, and cause transmitter 40 to issue appropriate transmissions. Optionally, system 100 includes a plurality of receivers 58 connected to a plurality of control valves 56, which may be located at a plurality of buildings or locations. In that embodiment, each receiver 58 may be controlled individually, or the plurality of receivers 58 may be broken into two or more groups that are controlled by a common transmission. In this way, the controller 70 may stagger releases of rainwater from the plurality of cisterns in order to control the flow caused by such releases and prevent a discharge from the CSO when control valves 56 are opened following a closure thereof. In certain embodiments, system 100 includes a solenoid in operative communication with the receiver 58 and the control valve 56 such that the control valve 56 is opened and closed in response to a signal from the transmitter 40. This may be accomplished by using a solenoid-controlled valve for the control valve 56 and a receiver 58 capable of generating an electrical signal or current to control the solenoid controlled valve. In certain embodiments, the control valve 56 is configured so that when no signal is received from the transmitter 30, the control valve 56 permits rainwater to flow out of the cistern 50 and the control valve is closed only when a signal is received by receiver 58. This may be accomplished by using a solenoid controlled valve that is open in the absence of a signal at the control valve 56.
In certain embodiments, discharge outlet 54 is located in the lower portion of the cistern 50, and the overflow outlet 60 is located in the upper portion of the cistern 50. This configuration takes advantage of gravitational flow to allow flow through the overflow outlet 60. However, it is possible to locate the overflow outlet 60 elsewhere within the cistern by adding an overflow outlet control valve to the system to control the flow of water in overflow outlet 60.
The drawing figures show an exemplary embodiment of the invention in several different states of operation. In
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The invention also may comprise a method of using a system disclosed herein for controlling discharges of untreated material from a Combined Sewer System that carries rainwater and sewage from a drainage basin and having a Combined Sewer Overflow for discharging untreated material. An exemplary embodiment of a method according the invention includes providing at least one cistern 50 located within the drainage basin served by the Combined Sewer System as seen in
While the invention has been described by illustrative embodiments, additional advantages and modifications will occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to specific details shown and described herein. Modifications, for example, could include changes to the materials used to make the cisterns; the use of different devices or methods to transmit signals among the detector, controller, transmitter, receiver and control valve; and the use of a controller that is a special-purpose computer, or electronic controllers rather than a general-purpose computer. These modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention not be limited to the specific illustrative embodiments, but be interpreted within the full spirit and scope of the appended claims and their equivalents.
