Abstract:
A chlorinator for wastewater treatment systems having a circulation pump and return flow line, which includes a tank having an internal space, a buoyant container within the internal space which intakes a determined quantity of disinfectant fluid through a check valve from a quantity of such fluid disposed in said tank. The check valve limits flow during operation of the circulation pump. Operation of the circulation pump causes flow through the return line, inducing distribution of the quantity of disinfectant fluid into the circulation tank. After cessation of the circulation pump, the check valve opens to reestablish the quantity of disinfectant fluid. Regardless of the duration of pumping, only the uniform volume of disinfectant fluid is supplied.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention related generally to chlorinators for wastewater treatment systems. More specifically, this invention is a chlorinator for wastewater treatment systems, which have a disinfectant chamber that permits a uniform volume of disinfectant to be used each cycle. 
     2. Related Art 
     Chlorinators, which use either solid or liquid disinfectants, are known to the prior art. Illustrative of chlorinators using solid disinfectants are U.S. Pat. No. 6,183,630 issued to Reeves on Feb. 6, 2001; U.S. Pat. No. 4,100,073 issued to Hopcroft on Jul. 11, 1978; U.S. Pat. No. 5,350,512 issued to Tang on Sep. 27, 1994; and U.S. Pat. No. 5,405,540 issued to Tang on Apr. 11, 1995. Illustrative of chlorinators using liquid disinfectants are U.S. Pat. No. 4,333,833 issued to Longley et. al. on Jun. 8, 1982; U.S. Pat. No. 4,019,983 issued to Mandt on Apr. 26, 1977 and U.S. Pat. No. 3,996,139 issued to Prince et al. on Dec. 7, 1976. 
     Chlorination is widely used as part of wastewater treatment systems. In practice, a disinfectant such as chlorine is introduced at a point in the wastewater treatment system after which sufficient time, either by flow into a storage tank or through a region of flow, occurs to permit the chlorine to effectively disinfect the contaminant-bearing wastewater. The amount of disinfectant added to the wastewater is referred to as the “dosage,” and is usually expressed as milligrams per liter (mg/l) or parts per million (ppm). The amount of disinfectant necessary to disinfect a particular volume of wastewater is referred to as the “demand.” 
     The reaction between the disinfectant and the contaminants is typically not instantaneous but is instead time dependent. In order to obtain adequate disinfection, the mixing of wastewater and disinfectant should be completed in the shortest time possible, ideally a fraction of a second. The amount of disinfectant remaining in the wastewater at the time of measurement is referred to as the “residual.” The residual is therefore determined by the demand subtracted from the dosage. 
     Prior art chlorinators, whether using a liquid or solid disinfectant, typically mix the disinfectant with the wastewater during the flow of wastewater through the wastewater treatment system. In the case of chlorinators using a solid disinfectant, such as those disclosed in U.S. Pat. No. 6,183,630 issued to Reeves on Feb. 6, 2001; U.S. Pat. No. 4,100,073 issued to Hopcroft on Jul. 11, 1978; U.S. Pat. No. 5,350,512 issued to Tang on Sep. 27, 1994; and U.S. Pat. No. 5,405,540 issued to Tang on Apr. 11, 1995, mixing occurs by wastewater flow about a plurality of disinfectant tablets. In such systems the disinfectant is mixed at a rate dependant on the surface area of the table in contact with the wastewater, the density of the wastewater and the flow rate of the wastewater, among other variables. In the case of chlorinators using a liquid disinfectant, such as U.S. Pat. No. 4,333,833 issued to Longley et. al. on Jun. 8, 1982 mixing occurs at a contactor in the flowline wherein disinfectant fluid is drawn from a reservoir by pressure differential. In such systems the amount of chlorine combined with the wastewater varies with the flow rate of the wastewater and; wastewater density. Thus it would be beneficial to the prior art to provide a chlorinator that dispenses a uniform volume of chlorine. 
     Typical water treatment systems contain sequential chambers for elimination of solid waste, which would not be consumed by aerobic action, for aerobic treatment of the wastewater, for clarification of the wastewater and for storage of treated wastewater prior to disbursal to the environment by a sprinkler system. Disinfectant is mixed with the treated wastewater between clarification and disbursal. Disbursal of treated wastewater by a sprinkler system is accomplished by mechanical pumping action. Such systems utilize a pump, which generates pressure in excess of that necessary for operation of the attached sprinkler system. As a result a pressure relief valve set to the necessary sprinkler pressure is located in the pump line prior to exit from the pump tank. This valve permits return of a necessary amount of treated wastewater into the pump tank so as not to exceed the necessary sprinkler pressure. Return of treated wastewater into the pump tank creates a turbulent area within the treated wastewater in the pump tank. It would be beneficial to the prior art to provide a chlorinator that dispenses a uniform volume of chlorine into this turbulent area without an external power supply. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the objects of my invention is to provide, inter alia, a chlorinator for aerobic waste treatment systems that: 
     dispenses a uniform volume of liquid disinfectant; 
     rapidly mixes the disinfectant fluid with the wastewater; and 
     functions without the need for a power source beyond that in an existing wastewater treatment system. 
     Other objects of my invention will become evident throughout the reading of this application. 
     My invention is a chlorinator for waste treatment systems that is in functional attachment to a pump line in a pump tank, which dispenses a uniform volume of disinfectant fluid during each pump cycle, regardless of the duration of the cycle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram of a typical septic system. 
     FIG. 2 is a partial cut-away side view of the wastewater treatment system pump tank of the present invention. 
     FIG. 3 a  is a partial cut-away side view of the exemplary chlorinator functionally attached to the flow return line of the pump line. 
     FIG. 3 b  is a partial cut-away side view of an alternative exemplary chlorinator functionally attached to the flow return line of the pump line. 
     FIG. 4 is a cross-sectional side view of a ball cock valve for use in the chlorinator. 
     FIG. 5 is a cross-sectional side view of a typical flow powered venturi vacuum pump. 
    
    
     DESCRIPTION OF THE INVENTION 
     As shown in FIG. 1, a typical water treatment system  100  contains a series of steps that prepare wastewater  15  for release into the environment. The exemplary water treatment system  100  has a solid waste elimination chamber  110 , an aerobic treatment chamber  120 , a clarification chamber  130 , a chlorine addition step  140  and a disbursal step  150 . This invention addresses the chlorine addition step  140 . 
     As shown in FIG. 2, the chlorinator  11  is in functional attachment to flow return line  12  of pump line  13  and, while in use, disburses a uniform volume of disinfectant fluid  14  through disinfectant fluid line  21 , into flow return line  12  to be mixed with return wastewater  22  and ultimately with wastewater  15  in the pump tank  16 . Pump tank  16  provides storage for wastewater  15  prior to being pumped by pump  17  to the sprinkler system  18 . Pump  17  transmits wastewater  15  at a pressure significantly higher than necessary for sprinkler system  18 . A pressure relief valve  19  in pump line  13  releases a sufficient volume of wastewater  15  into flow return line  12  to prevent damage to sprinkler system  18  due to excessive pressure. Pump  17  operates on an intermittent basis. Pump  17  is activated either by timer or by the level of wastewater  15  and operates until the termination of the time cycle or until wastewater falls below a specific level in pump tank  16 . At all times during operation of pump  17  some portion of wastewater  15  is diverted by pressure relief value  19  to flow return line  12  as return wastewater  22 . When return wastewater  22  flows through flow return line  12  disinfectant fluid  14  comes from chlorinator  11  through disinfectant fluid line  21  at disinfectant connection  20 . Disinfectant fluid  14  enters the return wastewater  22 , which returns to pump tank  16 , and mixes back into the balance of wastewater  15 . Disinfectant fluid  14  is thereby mixed with wastewater  15  in pump tank  16  during the operation of pump  17 . In a typical system, the pump  17  produces substantially more pressure than the maximum pressure of the sprinkler system  18 , so the return wastewater  22  pressure is also substantial, creating turbulence in the pump tank  16  upon its return to the wastewater  15 . 
     Referring to FIG.  2  and FIG. 5, in the exemplary embodiment the disinfectant connection  20  is a flow-powered venturi vacuum pump  200  located in flow return line  12 . As understood in the art and illustrated in FIG. 5, a flow-powered venturi vacuum pump  200  is a device which generates an area of reduced pressure in chamber  201  by passing a liquid, in this case return wastewater  22 , in flow return line  12 , through the chamber  201 , defined by a narrowed wall segment  202 . The reduced pressure in chamber  201  draws disinfectant fluid  14  through disinfectant fluid line  21 , out pump opening  205  and into flow return line  12 . 
     Referring to FIGS. 3 a  and  3   b , when the operation of pump  17  begins disinfectant fluid  14  is withdrawn from chlorinator  11 . In the exemplary embodiment the flow-powered venturi vacuum pump  200  draws the entire volume  23  of disinfectant fluid  14  into the wastewater  15  in under a minute. Once volume  23  is disbursed, chlorinator  11  ceases to supply additional disinfectant fluid  14  and instead supplies air, which is drawn from container  30 . Volume  23  is replenished after operation of pump  17  ceases and check valve  40  opens. 
     Chlorinator  11 , in FIGS. 3 a  and  3   b , includes an external tank  25  within which has been securely mounted an internal tank  27 . The interior of internal tank  27  defines a core space  45 . The space surrounding internal tank  27 , inside external tank  25  is an annular space  50 . Both core space  45  and annular space  50  are constructed to house a supply of disinfectant fluid. 
     External tank  25  and internal tank  27  are vented to the external atmosphere by vent  26  in a common top  36 . In an alternate exemplary embodiment, the common top  36  is threaded and not sealed so as to allow sufficient ventilation through the threads (not shown). External tank  25  and internal tank  27  share a common base  28 . Lower openings  29  have been created immediately above common base  28  through the wall  38  of internal tank  27 . External tank  25  and internal tank  27  share the common top  36 , below which upper openings  37  have been created through the wall  38  of internal tank  27 . External tank  25  and internal tank  27  communicate disinfectant fluid  14  and internal atmosphere through lower openings  29  and upper openings  37 , which serve to allow equal pressure between external tank  25  and internal tank  27 . 
     Chlorinator  11  in FIGS. 3 a  and  3   b  also includes container  30  fitted within internal tank  27  so as to restrict the motion of container  30  to vertical movement. Referring to FIG. 3 a , in the exemplary embodiment float  33  laterally surrounds the container wall  32 . Float  33  is sized so as to freely move along the internal sides  31  of internal tank  27 . Internal tank  27  thereby acts as a guide to restrict the lateral motion of container  30  and float  33 . Float  33  is composed of a buoyant material, which prevents container  30  from settling too far into the disinfectant fluid  14  supply contained in internal tank  27 . Volume  23  of disinfectant fluid  14  is the maximum volume of disinfectant fluid  14 , which can be communicated to container  30  based on the buoyancy of float  33  and container  30  when check valve  40  is open. 
     Referring to FIG. 3 b , an alternative exemplary embodiment has float  33  situated inside container  30 , proximate to container top  35 . In this embodiment disinfectant fluid line  21  extends through container top  35  and float  33  to immerse into volume  23 . Container  30  is sized so container wall  32  is proximate to the internal sides  31  of internal tank  27 . In this manner the internal tank  27  still acts as a guide to restrict the lateral motion of container  30 . 
     Disinfectant fluid line  21  penetrates external tank  25  and internal tank  27 . In the exemplary embodiment this is done through common top  36  within internal sides  31  of internal tank  27 . Disinfectant fluid line  21  is flexible and has sufficient length inside internal tank  27  to not interfere with the free movement of container  30 . Alternatively, disinfectant fluid line  21  may penetrate external tank  25  and internal tank  27  in other locations, so long as disinfectant fluid line  21  does not interfere with the vertical movement of container  30  within internal tank  27 . 
     Disinfectant fluid line  21  penetrates container top  35  and extends a fixed distance into container  30 . In FIG. 3 a , the exemplary embodiment disinfectant fluid line  21  is mounted to the internal bottom  39  of container  30 . At least one disinfectant fluid line opening  34  is provided in disinfectant fluid line  21  near internal bottom  39  of container  30  to allow volume  23  of disinfectant fluid  14  to be drawn from container  30 . 
     In FIG. 3 b , an alternative exemplary embodiment disinfectant fluid line  21  extends into container  30 , but does not extend all the way to the internal bottom  39 . Disinfectant fluid line opening  34  is thereby positioned a set distance from the internal bottom  39 . The level to which disinfectant fluid line opening  34  extends and the upper level to which disinfectant  14  in container  30  attains when check valve  40  is open defines volume  23  in this embodiment. 
     Referring to FIGS. 3 a  and  3   b , check valve  40  is also mounted near the internal bottom  39  of container  30  in wall  32  and, when open, permits communication of disinfectant fluid  14  from internal tank  27  to container  30 . A siphon relief opening  41  is located in the container top  35  of container  30 , and allows air displaced by the influx of disinfectant fluid  14  to escape. In an alternate exemplary embodiment siphon relief opening  41  is located in the container wall  32 , positioned above the upper level of volume  23 . When container  30  reaches volume  23  communication of disinfectant fluid  14  and air displacement ceases. 
     Referring to FIGS. 2,  3   a  and  3   b , when pump  17  is operating, disinfectant fluid  14  is drawn from chlorinator  11  through disinfectant fluid line  21  to flow return line  12 , and check valve  40  prevents additional disinfectant fluid from entering container  30 . Siphon relief opening  41  allows for a sufficient decrease in the pressure within container  30  to close check valve  40 , while not creating a vacuum sufficient to cause return wastewater  22  to be drawn into disinfectant line  21 . When pump  17  ceases operation, the pressure within container  30  balances with the internal atmosphere  24  through siphon relief opening  41 , allowing check valve  40  to open and permit disinfectant fluid  14  from internal tank  27  to flow into container  30 . Volume  23  is then replenished as disinfectant fluid  14  flows into container  30 . 
     As shown in FIG. 4, check valve  40  may be comprised of an upper sheet washer  401 , a valve ball  402 , and a lower sheet washer  403  having a notched exposed surface  404 . The valve ball  402  must be sufficiently dense as to not float in the disinfectant fluid  14 , yet buoyant enough to be moved by the disinfectant fluid  14  flowing through the check valve  40 . The term neutral buoyancy is used to describe the condition when an item neither sinks nor rises in a particular fluid. In the exemplary embodiment, valve ball  402  is of lesser buoyancy than neutral buoyancy in the disinfectant fluid, so valve ball  402  can unseat from upper sheet washer  401 . In the exemplary embodiment the valve ball  402  is a dense ceramic material. When pump  17  operates, disinfectant fluid  14  flows from container  30  through disinfectant fluid line  21 . The flow of internal atmosphere is moderated by the siphon relief opening  41 , and air pressure is reduced within container  30 . The reduced pressure increases the force with which the disinfectant fluid  14  attempts to enter container  30  through check valve  40 , passing through inlet opening  405 . The reduced pressure within container  30 , together with the buoyancy effect of liquid disinfectant, causes the valve ball  402  to seat against upper sheet washer  401 , preventing further communication of disinfectant fluid  14  from internal tank  27  to container  30 , through outlet opening  406 . 
     When pump  17  ceases, the air pressure within container  30  increases as atmosphere from within internal tank  27  enters through siphon relief opening  41 . The increased pressure within container  30  decreases the air pressure exerted on the valve ball  402  of the check valve  40 . With increased relative air pressure in container  30 , the pressure of the disinfectant fluid  14  against the valve ball  402  is not sufficient to maintain a seal between the valve ball  402  and upper sheet washer  401 . Valve ball  402  may completely unseat from upper sheet washer  401  and settle on lower sheet washer  403 . The notched exposed surface  404  of lower sheet washer  403  prevent the ball cock from securely seating on lower sheet washer  403 . This ensures that the disinfectant fluid  14  may freely intermingle, both inside and outside of container  30  through check valve  40  while pump  17  is not operating. 
     In an alternate embodiment check valve  40  may be oriented generally horizontally. The force with which the disinfectant fluid  14  attempts to enter container  30  through check valve  40  during the operation of pump  17  lifts valve ball  402  into a position to occlude the hole in upper sheet washer  401 . When pump  17  ceases, the air pressure within container  30  increases as atmosphere from within internal tank  27  enters through siphon relief opening  41 . The increased pressure within container  30  decreases the air pressure exerted on the valve ball  402  of the check valve  40 . With increased relative air pressure in container  30 , the pressure of the disinfectant fluid  14  against the valve ball  402  is not sufficient to maintain a seal between valve ball  402  and upper sheet washer  401 . Valve ball  402  falls away from the hole in upper sheet washer  401  permitting disinfectant fluid to flow into container  30 . 
     Referring to FIGS. 3 a  and  3   b , an anti-siphon aperture  42  penetrates disinfectant fluid line  21  within internal tank  27 . The anti-siphon aperture  42  is so sized as to allow very little airflow in relationship to the disinfectant fluid  14  flow in disinfectant fluid line  21  when the pump  17  is operating. The anti-siphon aperture  42  allows for a periodic bubble (not shown) of internal atmosphere to be drawn into the disinfectant fluid  14  being drawn through disinfectant fluid line  21 . When pump  17  is not operating, airflow through the anti-siphon aperture  42  prevents a siphon effect from continuing to draw disinfectant fluid  14  from the chlorinator  11 . Disinfectant fluid  14  on the chlorinator  11  side of the bubble (not shown) will return to container  30 , while the remaining disinfectant  14  in disinfectant fluid line  21  will flow on to pump tank  16 . 
     In the exemplary embodiment, anti-siphon aperture  42  draws air from within chlorinator  11 , which is relatively saturated with disinfectant gas, thereby possessing less capacity to degrade the disinfectant fluid with which it comes in contact. 
     The foregoing disclosure and description of the invention is illustrative and  11  explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.