This invention relates to water treatment, and more particularly to an apparatus and a method for introducing a chemical solution into a water stream at a high delivery rate and at a controlled concentration.
Water treatment is needed in a variety of applications. Untreated water provides a hospitable environment for the growth of bacteria, algae, and other undesirable and potentially unhealthy organisms. It has become common practice to treat water on a periodic or continuous basis by introducing chemicals to control such bacteria, algae, and organisms.
Chemical feeders have been developed to bring water into contact with solid, dry chemicals to dissolve the chemical material in the water in a controlled manner and to create a chemical solution that is then introduced into a water stream to treat a body of water. For example, when calcium hypochlorite is used to treat a body of water, chlorine is introduced into the water stream and the quantity of chlorine in the water generally expressed as a concentration of free available chlorine (FAC). In this instance, the feeder must be able to dissolve the calcium hypochlorite at a desired rate, so as to maintain a desired FAC concentration, while avoiding undesirable calcium carbonate deposits or residues.
In a typical application, such as public water supplies, cooling towers, and other industrial applications, chemical feeders for water treatment are able to provide a continuous supply of treated water where such a constant treatment of water must be assured. However, in emergency situations where a rapid delivery of a chemical solution is necessary, a typical chemical feeder application is inadequate. It is therefore desirable to implement a chemical feeder that can quickly and efficiently deliver a chemical solution in emergency situations to treat a body of water.
The present invention relates generally to a rapid rate chemical solution generator system that can quickly and efficiently produce a chemical solution for an application that requires immediate attention. For example, the system may be advantageously used in cases of a disruption of a municipal water supply, sewer overflow, in cooling towers, and in other industrial applications that require delivery of a chemical solution at a rapid rate in a short period of time. Generally, the system includes a tank for mixing chemical material with water, a hopper for storage of the chemical, and a mixer to formulate the chemical solution. The system is configured to provide long-term storage of the chemical material while being ready for rapid delivery of the chemical material to the tank when needed. In operation, the chemical material can be loaded into the tank either manually or automatically via a hopper. The chemical material is then rigorously agitated using the mixer to disperse the chemical and create a solution to treat a body of water. The system may also include a programmable logic controller and load cells to control the delivery rate and concentration of the solution.
Broadly, the present invention relates to a method for preparing a chemical solution via a rapid rate chemical solution generator system, which includes a hopper, a tank located below the hopper, a supply valve disposed between the hopper and the tank, a mixer extending into the tank, and a pump connected to the tank. The method comprises the steps of placing a dry chemical, such as briquettes or granules, in the hopper, activating a first signal to indicate that a chemical solution is required for water treatment, filling the tank with fluid in response to the first signal to a predetermined upper level, subsequently turning the mixer on and concurrently opening the chemical supply valve to allow at least a portion of the dry chemical to drop into the tank, shearing and mixing the dry chemical with the fluid to produce a chemical solution, then activating the pump to remove the chemical solution from the tank so that the chemical solution can be dispersed into a body of water that requires treatment, thereby lowering the level of the fluid in the tank to a predetermined lower level. The dry chemical used in the method can be, for example, calcium hypochlorite, and the strength of the chemical solution can be adapted to be in the range of 0.5% available chlorine to 15% available chlorine. Moreover, the hopper can be configured to store the dry chemical for at least one day, and when the dry chemical is admitted to the tank it can be at a rate in the range of about 1 lb. per day to about 700 lb. per day.
The method can also include a second signal that is generated once the level of the fluid in the tank is at or below the predetermined lower level. In response to a second signal, the tank is refilled with the fluid and the hopper is refilled with the dry chemical.
Additionally, the solution generator system can be adapted to further include an inlet valve and a control unit that is connected to the chemical supply valve and the inlet valve. Here, the control unit is configured to receive the first signal and the second signal. Moreover, the control unit is configured to control a strength of the chemical solution by adjusting the supply valve to control a feed rate of the dry chemical to the tank and the inlet valve to control the amount of fluid entering the tank.
The method can further include a step where the control unit receives a remotely generated signal that indicates the strength of the chemical solution to be prepared.
Yet another possible method step can include flushing the tank to drain and rinse the tank and the pump prior to refilling the tank with fluid and the dry chemical.
Additionally, the present invention relates to a system for preparing a chemical solution, which comprises a tank, a hopper mounted above the tank, a supply valve disposed between the hopper and the tank, a mixer, which is mounted to the tank and is partially disposed in the tank, and a pump connected to the tank to draw the chemical solution out of the tank. The hopper, which can be made of plastic, is configured to store a chemical, which can be a dry chemical, for at least six months. The supply valve can be a knife-gate valve. The mixer can be mounted to the tank at an angle to aid in agitating and blending the chemical with water to produce the chemical solution.
The system can also include a discharge valve that is mounted to a sidewall of the tank to allow the chemical solution to exit the tank. Moreover, the system can include a discharge line that extends from the discharge valve and a pump inlet line that extends from the discharge line to the pump. Furthermore, the system can include two pumps, a first pump and a second pump, that are connected to the tank. In this instance, the system could also include a first pump inlet line that extends from the discharge line to the first pump and a second pump inlet line that extends from the discharge line to the second pump.
Additionally, the system can include a monitor device for monitoring a level of fluid in the tank, a pump control device for controlling activation of the pump, a water inlet control device for controlling inlet of water to the tank, a mixer control device for controlling the mixer between an on state and an off state, and a valve control device for controlling the supply valve between an open state and a closed state. The water inlet control device is configured to cause the tank to fill with water to a predetermined upper level in response to a first signal. The mixer control device is configured to cause the mixer, in a first state, to turn on subsequent to the fluid level attaining the predetermined upper level and, in a second state, to turn off once the fluid level reaches a predetermined lower level. The valve control device is configured to cause the supply valve to open concurrently with the mixer being turned on, thereby causing the dry chemical to enter the tank. The pump control device is configured to activate the pump to remove the chemical solution from the tank with the pump remaining activated while the level of fluid in the tank is at or above the predetermined lower level, so that the system is configured for automated standby operation.
The system can further include an alarm and a diagnostic device configurable by a system user, and at least one of a programmable human-machine interface and a programmable logic controller Those skilled in the art should appreciate that they can readily use the disclosed invention and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention and that such other structures do not depart from the spirit and scope of the invention in its broadest form.
The present invention will be further understood and appreciated by reading the following description in conjunction with the accompanying drawing, in which:
To ensure proper operation of the system 10, control/monitor units/devices 40, 42 control the operation of the water inlet 64, which is controlled via a water inlet control device (not shown), the pumps 22, 24, via a pump control device (not shown), the gate valve 16, via a gate control valve (not shown), and the mixer/homogenizer unit 20 via a mixer control device (not shown). The control/monitor units/devices 40, 42 also receives an input from a monitor device (not shown) for monitoring the level of fluid in the tank 12. Each of the water inlet control device, the pump control device, the gate valve control device, mixer control device may be conventional devices known to those skilled in the art such as solenoids, load cells and the like. The device for monitoring the level in the tank may be any suitable monitoring devices such as a float in the tank, a pressure sensor which measures the pressure generated by the hydraulic head in the tank, and the like. Each of these devices may be connected to the control/monitoring units 40, 42 via a wiring (not shown) or wirelessly (not shown), using known techniques. It will be appreciated that the system 10 is capable of automated operation, where a chemical solution is delivered to a point of application in response to an external signal, without operator intervention. Additionally, the system 10 can include a programmable human-machine interface and/or a programmable logic controller, which may be located in control/monitor units 40, 42, or may be a portable device, such as a laptop computer, smartphone, tablet computer, or other similar device which can be plugged into the control/monitor units 40, 42 via a connector, such as a USB connection. The control/monitoring units 40, 42 may also have an alarm (not shown) and/or a diagnostic device (not shown) for diagnosing any problems or issues with the system.
Depending on the application of the chemical solution, the strength of the solution can be customized by varying the rate at which the chemical material is allowed to fall into the tank 12, which can be, for example, 1 lb/day to 700 lbs/day. Also, in the case of calcium hypochlorite, the solution strength can roughly be in the range of 0.5% to 15% of FAC. To aid in controlling the feed rate of the chemical from the hopper 14 to the tank 12 and the concentration of the solution, the system has a programmable logic controller and load cells are used. In the embodiment described herein, the system 10 is fully automated and is activated by the first signal 62 and the second signal 66 from a remote application point, without operator intervention. The chemical material can be added to the hopper during the process, either manually or automatically. Moreover, the system 10 may be operated as a “single charge” system, where the entire contents of the hopper 14 are emptied into the tank 12 so that a concentrated water treatment solution can then be delivered in a few minutes.
While the invention has been described in terms of a specific embodiment, it is evident in view of the foregoing description that numerous alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications, and variations which fall within the scope and spirit of the invention and the following claims.
This application claims priority under 35 U.S. §119(e) from U.S. Ser. No. 61/547,399 filed Oct. 14, 2011. The disclosure of U.S. Ser. No. 61/547,399 is incorporated herein by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
61547399 | Oct 2011 | US |