Abstract:
An apparatus for associating a solution at an infinitely-variable level and/or flow rate with respect to an agent including an agent amount indicator that promotes agent-solution association adaptable for use in a chlorinator, or comparable component, of a fluid treatment plant. An embodiment configured according to the invention includes a chamber with an inlet and a vertically-inferior outlet. The level and flow of fluid in the chamber is regulated by a weir mounted on the outlet. Fluid in the chamber passes through an agent the retainer maintained in the chamber and washes over the agent, dissolving and depleting the agent. A magnetic follower on top of the agent urges the agent toward the bottom of the retainer. As the agent becomes depleted, the follower approaches the bottom of the retainer until it attains a predetermined distance from a sensor which activates a low-agent-supply alarm.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to waste water treatment. Specifically, the invention relates to ensuring that a proper amount of an agent is associated with water and waste water during treatment. 
     2. Discussion of Related Art 
     Water and wastewater treatment processes typically introduce into an aqueous solution to be treated a disinfectant or biocidal agent, such as bromine or chlorine. Chlorine perhaps is the most common water and wastewater agent used throughout the world, today. Large wastewater treatment plants commonly use chlorine gas or liquid. Small plants, such as home wastewater treatment plants and some commercial wastewater treatment plants use chlorine tablets, composed of mainly calcium hypochlorite. 
     A variety of techniques are known or used for introducing these and other agents into an aqueous solution. Some treatment processes involve manually adding a liquid or granular agent to the solution. A drawback to this method is exposing the person handling the agent to potentially hazardous chemicals. Another drawback is the deterioration of the activeness of the agent when exposed to ambient conditions, such as humidity. 
     Some processes employ an agent distributor, such as a dissolve- or erosion-type flow-through feeder. Dissolve/erosion-type feeders typically introduce low-solubility agents into aqueous systems. Generally, dissolve/erosion feeders operate by establishing a flow of solution through the feeder to cause surface friction between the solution and the agent granules or tablets, thereby eroding the surfaces thereof and dissolving the displaced particles. See, for example, U.S. Pat. No. 5,405,540, issued Apr. 11, 1995, to N. Tang. Some apparatuses and processes monitor the amount of agent dispensed. See, for example, U.S. Pat. No. 5,064,531, issued Nov. 12, 1991, to L. K. Wang et al. However, a significant drawback of these dissolve/erosion-type feeders is, because granule/tablet dissolution rate is dependent on solution temperature and flow rate, inter alia, the difficulty in predicting agent quantity requirements. 
     To better control the amount of agent dispensed, an agent feeder has been positioned in a container in which solution level and flow rate therethrough are controlled. However, the mechanisms for doing so do not lend to critical, incremental adjustments. See, for example, U.S. Pat. No. 3,595,786, issued Jul. 27, 1971, to R. J. Horvath et al. and U.S. Pat. No. 4,759,907, issued Jul. 26, 1988, to R. J. Kawolics el al. 
     Some devices indicate agent level. See, for example, U.S. Pat. No. 4,986,902, issued Jan. 22, 1991, to P. Serna. Other devices and methods only indicate low or depleted agent supply. See, for example, U.S. Pat. No. 3,680,736, issued Aug. 1, 1972, to H. Viesmann and U.S. Pat. No. 5,076,315, issued Dec. 31, 1991, to J. A. King. Still other devices measure and report agent amount for monitoring purposes. See, for example, U.S. Pat. No. 4,830,757, issued May 16, 1989, to J. T. Lynch et al. and U.S. Pat. No. 5,427,694, issued Jun. 27, 1995, to L. E. Rugg. 
     Some devices include an alarm that is activated when an agent is depleted or attains a low level. See, for example, U.S. Pat. No. 3,655,050, issued Apr. 11, 1972, to R. L. Fifer. Some alarm devices even exploit magnetic phenomena. See, for example, U.S. Pat. No. 5,297,428, issued Mar. 29, 1994, to L. L. Carr et al. 
     Unfortunately, none of the foregoing provides for associating a solution at an infinitely-variable level and/or flow rate with respect to an agent or an agent amount indicator that also promotes agent-solution association. None of the aforementioned references, taken alone or in combination, are seen as teaching or suggesting the presently claimed Solution Treatment Agent Supply Apparatus. 
     SUMMARY OF THE INVENTION 
     The invention is an apparatus for associating a solution at an infinitely-variable level and/or flow rate with respect to an agent. The invention also provides an agent amount indicator that promotes agent-solution association. The invention improves on septic systems commonly used in communities in which houses are not connected to centralized sewage systems. The invention provides for more completely reducing waste received in these septic systems before voidance into the environment. As a result, the soil surrounding a septic tank incorporating features of the invention, or leach field, is less contaminated and presents less of a biological hazard to local inhabitants. Since the surrounding soil is less contaminated, fewer contaminates percolate into the water table from which local inhabitants draw drinking water. The invention also promotes cleaner, more healthful air, since fewer contaminants that may become airborne from the soil, carrying sickness or at least foul odors to the inhabitants, are exposed to the air. The invention provides improved elements and arrangements thereof, in an apparatus for the purposes described which are inexpensive, dependable and effective in accomplishing its intended purposes. 
     The invention is adaptable for use in a chlorinator, or comparable component, of a fluid treatment plant. The invention also is adaptable for use with drinking fountains, or any fluid system that includes associating an agent with fluid to be treated. An embodiment of an agent supplier configured according to the invention includes a chamber with an inlet and a vertically-inferior outlet. The level of fluid in the chamber and flow therethrough is regulated by a weir mounted on the outlet. A flow-through agent retainer containing agent tablets is received through the top of and rests on the floor of the chamber. Fluid in the chamber passes through the retainer and washes over the agent, dissolving and depleting the agent. A magnetic follower on top of the agent urges the agent toward the bottom of the retainer. As the agent becomes depleted, the follower approaches the bottom of the retainer. When the follower attains a predetermined distance from a sensor, the sensor activates a low-agent-supply alarm. 
     These and other features of the invention will be appreciated more readily in view of the drawings and detailed description below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in detail below with reference to the following drawings, throughout which similar reference characters denote corresponding features consistently, wherein: 
     FIG. 1 is a vertical cross-sectional detail view of an embodiment of a waste water treatment tank including an agent supplier constructed according to principles of the invention; 
     FIG. 2 is a top front right side elevational view of an embodiment of an agent supplier constructed according to principles of the invention; 
     FIG. 3 is right side elevational view of the embodiment of FIG. 2; 
     FIG. 4 is a vertical cross-sectional detail view of the embodiment of FIG. 2; and 
     FIG. 5 is a right side elevational view of a weir plate of the embodiment of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is an apparatus for associating a solution at an infinitely-variable level and/or flow rate with respect to an agent. An embodiment of an agent supplier configured according to the invention includes a chamber with an inlet and a vertically-inferior outlet. An adjustable weir on the outlet regulates fluid level and flow through the chamber in association with agent tablets that are biased toward the bottom of the tank 
     Referring to FIG. 1, the present agent supplier  10  is shown incorporated in a conventional waste water treatment plant A. The treatment plant A includes a pre-treatment tank B, a treatment tank C and a holding tank D. Untreated solution flows into the pre-treatment tank B, into and through the treatment tank C, into and through the agent supplier  10 , into and through the holding tank D, then is voided into the environment. 
     The pre-treatment tank B is where inflowing fluids enter the aerobic system. The pre-treatment tank B receives raw, untreated sewage, which is allowed to settle. The pre-treatment tank B also retains any non-biodegradables inadvertently introduced into the system, such as rags and plastic, which settle out prior to introduction of the fluid into the treatment tank. Some aerobic decomposition of the effluent also begins in the pre-treatment tank B. 
     The treatment tank C is where the bulk of the aerobic decomposition of the effluent occurs. The treatment tank C includes walls E and a floor F. A hopper G mounted in the tank C cooperates with the walls E and floor F to define aerator zones H and an interior clarifier chamber I. Diffusers J in the treatment tank C promote flow in the aerator zones H which enhances the oxygen content of the solution in the tank C and breakdown of solid matter in the solution. In the aerator zones H, sewage aeration thoroughly mixes the organic materials of the sewage with the bacterial population, so that bacteria attacks and reduces the organic materials. Aerated and reduced solution from the aeration zones H passes into the clarifier chamber I. The throat-like lower aperture of the hopper G minimizes fluid flow within the clarifier chamber I, thus encourages the settling out of particulate matter in the clarifier chamber I back into the aerator zones H for additional breakdown. 
     Rather than passing effluent from the clarifier chamber I into the holding tank D, the invention provides for additional treatment of the effluent from the clarifier chamber I. The additional treatment kills any remaining bacteria which may pose a health risk to humans and animals nearby where treated solution is pumped out of the holding tank D. Solution from the clarifier chamber I passes into the agent supplier  10  where the solution is associated with a biocidal agent, such as chlorine. 
     The holding tank D receives treated fluid from the agent supplier  10  where it remains for a period of time. Any remaining particulate matter settles out prior to being pumped by a pump K out of the system into the environment. 
     Referring also to FIGS. 2 and 3, the agent supplier  10  includes a chamber  15  which may be constructed from plastic or fiberglass or any other suitable material. In the application shown in FIG. 1, the chamber  15  has a sleeve  17  for suspending the agent supplier  10 , in this case from the cover L of the holding tank D. Other suitable mechanisms may be employed for positioning the agent supplier  10  in the holding tank D, or other appropriate location, or as required for different applications. 
     The chamber  15  has an inlet  20  and an outlet  25 . The inlet  20  is vertically superior to the outlet  25  to encourage flow from the clarifier chamber I through the chamber  15  and out the outlet  25  into the holding tank D. It is not desirable to have fluid from the chamber  15  flow back through the inlet  20  into the clarifier chamber I because such fluid has come into contact with a biocidal agent. If this biocidal agent were introduced into clarifier chamber I, necessary bacteria for breaking down solids in the aerator zones H in the treatment tank C would be hindered, if not eliminated. 
     Referring to FIGS. 1 and 4, the agent supplier  10  includes an agent retainer  60  which, in the application shown in FIG. 1, is received in the sleeve  17 , and extends into the chamber  15 . A collar  70  extends from the cover L and may receive the agent retainer  60  in the same fashion as the sleeve  17 . A cap assembly  75  selectively closes the collar  70 , discouraging entry of dirt and so forth, yet affording access to the agent retainer  60  for supplying agent thereto. 
     The agent retainer  60  receives agent  85 , preferably in the form of a plurality of tablets. As mentioned above, the agent preferably is chlorine, but may be any compound suitable for an Application for which the invention is adapted. The agent retainer  60  is configured to receive the agent  85  in a manner that maintains the agent  85  in an orderly fashion for controlled introduction into the chamber  15 , as described below. In the case where the agent  85  is in tablet form, for example, the agent retainer  60  should be configured to receive agent tablets in a stack for serial advancement through the agent retainer  60 , as shown. 
     As shown in FIG. 3, the agent retainer  60  has slots  90 . Preferably, the slots  90  are radially diverged and axially aligned with respect to the agent retainer  60 . As shown in FIG. 4, the agent retainer  60  also has one or more grate(s) or screen(s)  95 . The screen(s)  95 , preferably, define(s) the bottom of the agent retainer  60 . The configuration, number and location of the slots  90  and screens  85  provide for optimal association between the solution and agent in the agent retainer  60 . 
     The agent retainer  60  has a punt  100  extending from the screen  95  or bottom thereof. The punt  100  maintains the agent  85 , in this case the tablets, above the bottom or screen  95  of the agent retainer  60  and the floor  105  of the chamber  15 . The punt  100  elevates the agent  85  in the agent retainer  60  so that the agent  85  is not totally immersed in solution. Especially in the case where the agent  85  is in the form of tablets, avoiding total immersion of the tablet-form agent  85  helps to preserve the integrity of the tablet, slowing tablet degradation and affording the operator more control over the amount of agent desired to be associated with the solution. The punt  100  also elevates the agent  85  so as to expose the lower surface of the agent  85 , thus promoting depletion from the bottom; allowing the agent  85  to settle increases the potential for the agent  85  to fuse with the floor  105 , less available for associating with the solution. Elevating the agent  85  within the agent retainer  60  also reduces the potential for the agent  85  to partially dissolve and clog passages through the screen  95 . 
     Referring also to FIG. 1, in one application of the invention, solution flows from the clarifier chamber I through the chamber  15 , through the slots  80  and screen  95  of the agent retainer  60 , then out the outlet  25  into the holding tank D. The amount of agent  85  associated with and introduced into the solution depends on the level  57  and flow of the solution in the chamber  15 , hence with respect to the agent retainer  60 . Controlling the amount of agent supplied is important from cost and health standpoints. If too much agent is supplied to the solution, agent is wasted, thus increasing the operating costs of solution treatment. Too much agent introduced into the treated solution ultimately voided into the environment also may have a toxic effect on the indigenous plants and animals. On the other hand, if too little agent is supplied to the solution, treated solution ultimately voided into the environment may contain an unacceptable level of bacteria or other pathogens that may harm the indigenous plants and animals. 
     Referring again to FIG. 2, to control solution level and flow rate in the chamber  15 , flow through the outlet  25  is regulated by a weir  30 . The weir  30 , described in U.S. Pat. No. 5,680,989, is adjustable, thus provides for adjusting the level of fluid  57  inside the chamber  15  as well as the flow therethrough. Referring also to FIG. 5, a slideable weir plate  35  is sandwiched between a support plate  40  and a plug body  45 , shown in FIG.  3 . Once assembled, as shown in FIG. 3, an adjustment knob  50  may be rotated to translate the weir plate  35  vertically up and down relative to the support plate  40 . Translating the weir plate  35  changes the position of the weir opening  55  relative to the outlet  25 . Changing the position of the weir opening  55  also changes the position of the weir opening  55  relative to the bottom  105  of the chamber  15 , which impacts the solution level in the chamber  15 . For example, raising the weir opening  55  relative to the bottom  105  of the chamber  15  causes more solution to collect in the chamber  15  before reaching the opening  55 . 
     As mentioned in U.S. Pat. No. 5,680,989, the shape of the weir opening  55  is configured to maintain substantially constant flow through the chamber  15 , regardless of the solution level  57  in the chamber  15 . Maintaining substantially constant flow through the chamber  15  occurs because of the vertically-expanding configuration of the weir opening  55 . As the solution level rises relative to the weir opening  55 , the effective passage increases, allowing greater flow therethrough. Higher solution levels generally are accompanied by a corresponding volume increase before the weir  30 . In order to maintain steady flow through the chamber  15 , a greater volume of fluid must pass through the weir  30 . To do so, the weir opening  55  provides a wider passage at higher fluid levels, such as at fluid level  59 . 
     Referring again to FIG. 4, a follower  110  sits on top of the agent  85 . The follower  110  has a mass that, under the influence of gravity, imparts sufficient force to advance the agent  85  through the agent retainer  60 . Forcefully advancing the agent  85  through the agent retainer  60  often is required die to expansion of the agent from absorption of moisture in the agent retainer  60 . Thus, the mass of the follower  110  depends on factors, such as agent integrity and the impact the operating environment of the agent supplier on agent integrity and expansion. The configuration of the follower  110 , preferably, corresponds to the configuration of the agent  85 . For example, where the agent  85  is in tablet form, the follower  110  assumes the configuration of an agent tablet. 
     To introduce agent into the agent retainer  60 , the follower  110  first must be removed from the agent retainer. To prevent losing the follower  110 , a cord  115  may connect the follower  110  to the cap assembly  75 . 
     An important consideration to solution treatment systems, particularly septic and drinking water systems, is the assurance that the system contains a sufficient amount of agent to treat the solution. If the agent retainer  60  contains an inadequate supply of agent  85 , the solution is inadequately treated, as described above, which may lead to sickness and regulatory issues. 
     To address this concern, the invention provides for monitoring the amount of agent in the agent supplier  10 . To that end, the agent supplier  10  includes a sensor  120  that is responsive to the relative location of the follower  115 , thus the level of the agent  85  in the agent retainer  60 . Accordingly, the follower  110  is constructed so that it influences the sensor  120  within a predetermined zone of influence. The zone of influence corresponds to an amount of agent  85  remaining in the agent retainer  60  which is anticipated to be sufficient to treat the solution for a sufficient amount of time that allows for agent replenishment. For example, where the agent is in tablet form, the zone of influence may define the boundary at which only 1½ tablets remain in the agent retainer  60 . The sensor  120 , shown mounted on the floor  105  of the chamber  15 , may be mounted anywhere the sensor  120  optimally may sense when the follower  110  falls within the predetermined zone of influence in the agent retainer  60 . Preferably, the follower  110  is magnetic and the sensor  115  is responsive to magnetic fields and/or fluctuations therein. 
     In operation, as agent  85  is depleted from association with the solution flowing through the chamber  15 , the follower  110  urges the agent down through the agent retainer  60 . As the agent advances down through the agent retainer  60 , the follower  110  also advances through the agent retainer  60 . When the follower  110  enters the zone of influence, the sensor  120  responds and activates an alarm  125 . The alarm  125  may assume any form, such as a visual or audible signal. The alarm  125  is configured to adequately warn the solution treatment system operator or maintenance personnel that the system requires replenishment. 
     The invention is not limited to the foregoing, but encompasses all improvements and substitutions consistent with the principles of the invention.