Abstract:
Water treatment apparatus for supplying ozonated water to appliances, such as clothes washing machines. First and second water aspirators include respective first and second Venturi tubes. One aspirator is designed for a relatively higher water flow rate, and the other is designed for a relatively lower water flow rate. A valve selectively directs water from a water inlet to a water outlet through either the first or the second water aspirator. Ozone from an ozone generator is drawn either into water flowing through the first Venturi tube or water flowing through the second Venturi tube, depending on the position of the valve. A water flow sensor includes a microphone physically connected for sensing a sound characteristic of operation of a Venturi tube. A controller effects a time delay for maintaining activation of the ozone generator for a predetermined time duration even after water flow has ceased.

Description:
BACKGROUND OF THE INVENTION 
     Disclosed herein is an improvement of the embodiments described in Johnston U.S. patent application Ser. No. 13/898,095, filed May 20, 2013, and published as Pub. No. US 2013/0306569 on Nov. 21, 2013, the entire disclosure of which is hereby expressly incorporated by reference. 
     The invention relates to the treatment of water with ozone for supply to appliances, particularly clothes washing machines. 
     Ozone (chemical formula O 3 ) is well known as a powerful oxidant. A number of methods are known for producing ozone. Corona discharge is a common method, and is employed in embodiments of the invention disclosed herein. Another common method for generating ozone generator employs an ultraviolet light (UV). Other methods for generating ozone are a cold plasma method, and electrolytic ozone generation. Embodiments of the invention, however, are not limited to any particular type of ozone generator. It is also well known that ozone can be dissolved in water, and also can exist as small bubbles in water, both of which are known as ozonated water. 
     The use of ozonated water in a clothes washing machine has a number of advantages. As examples, the use of detergent can be reduced or eliminated. As a result, expense for detergent is reduced or eliminated, as well as build up of detergent residue. (Related to the reduction or elimination of detergent, the wastewater from a clothes washing machine supplied with ozonated water is considered “green,” without high levels of biological oxygen demand (BOD) food for bacteria.) Cold water can be used for clothes washing, providing energy savings from reduced hot water usage. The life of clothing, as well as the life of a washing machine, can be extended. 
     Ozonated water used in a clothes washing machine can remove irritating chemicals from clothing. This is particularly important for persons with chemical sensitivity. 
     In addition, ozonated water significantly reduces microbes, including mold, bacteria and viruses. 
     SUMMARY OF THE INVENTION 
     In one aspect, water treatment apparatus is provided. The water treatment apparatus has a water inlet and a water outlet, as well as first and a second water aspirators including respective first and second Venturi tubes through which water can flow. Each of the Venturi tubes has a water inlet port, a water outlet port, and a vacuum port. The first Venturi tube is designed for a relatively higher water flow rate and the second Venturi tube is designed for a relatively lower water flow rate. The water treatment apparatus also has a valve with two positions for selectively directing water from the water inlet to the water outlet through either the first or the second water aspirator. An ozone generator has an output connected to the vacuum ports. As a result, gas including ozone is drawn either into water flowing through the first Venturi tube or water flowing through the second Venturi tube, depending on the position of the valve. 
     In another aspect, water treatment apparatus is provided. The water treatment apparatus has a water inlet and a water outlet, as well as at least one water aspirator including a Venturi tube through which water can flow. The Venturi tube has a water inlet port, a water outlet port, and a vacuum port. An ozone generator has an output connected to the vacuum port. As a result, gas including ozone is drawn into water flowing through the Venturi tube. A water flow sensor includes a microphone physically connected for sensing a sound characteristic of operation of the Venturi tube. The water flow sensor is connected to a controller for activating the ozone generator when water is drawn out of the water outlet and thereby through the at least one water aspirator. 
     In yet another aspect, water treatment apparatus is provided. The water treatment apparatus has a water inlet and a water outlet, as well as at least one water aspirator including a Venturi tube through which water can flow. The Venturi tube has a water inlet port, a water outlet port, and a vacuum port. An ozone generator has an output connected to the vacuum port. As a result, gas including ozone is drawn into water flowing through the Venturi tube. A water flow sensor is connected to a controller for activating the ozone generator when water is drawn out of the water outlet and thereby through the at least one water aspirator. The controller effects a time delay for maintaining activation of the ozone generator for a predetermined time duration even after water flow as sensed by the water flow sensor has ceased. As a result, the ozone generator operates continuously when water is intermittently drawn out of the water outlet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of water treatment apparatus embodying the invention; 
         FIG. 2  is a three dimensional view, showing an exemplary mechanical layout within the interior of the water treatment apparatus shown schematically in  FIG. 1 ; 
         FIG. 3  is a three dimensional left side view of the water treatment apparatus, showing an air dryer employing a desiccant; 
         FIG. 4  is a view taken on line  4 - 4  of  FIG. 2 , showing LEDs which illuminate a mixer within the water treatment apparatus; 
         FIG. 5  is a three-dimensional top view of the water treatment apparatus showing a window through the mixer is observed, as well as LED color; 
         FIG. 6  is a three-dimensional rear view of the water treatment apparatus, showing a control for a two-position valve employed during initial setup of the apparatus; 
         FIG. 7  is a highly schematic representation of a controller, which in turn includes a microcontroller, within the water treatment apparatus of  FIGS. 1 and 2 ; 
         FIG. 8  is a flow chart of an “Ozone Generator Control Routine” that runs within the microcontroller; and 
         FIG. 9  is a flowchart of a “Failure Detect Routine” that also runs within the microcontroller. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to both the schematic diagram of  FIG. 1  and the exemplary mechanical layout of  FIG. 2 , water treatment apparatus  20  embodying the invention includes a water inlet  22  for connection, as an example, to a domestic cold water supply, as well as a water outlet  24  for connection, as an example, to the cold water inlet of a domestic clothes washing machine. Within the apparatus  20 , the water inlet  22  is connected to a water outlet  24 . The apparatus  20  functions to ozonate water supplied to the water inlet  22  and delivered at the water outlet  24 . 
     Accordingly, the apparatus  20  additionally includes an ozone generator, generally designated  30 , and an air inlet  32 , which receives ambient air. Ozone generators are well known. In the particular embodiment disclosed herein, the ozone generator  30  employs corona discharge. Accordingly, the corona discharge ozone generator  30  employs a high voltage power supply (not shown) which generates a voltage applied across glass dielectric plates (not shown) to develop a corona discharge, which then produces ozone from oxygen in the ambient air. Venturi tube vacuum, described in greater detail hereinbelow, draws air from the air inlet  32 , across the dielectric plates to produce a gaseous mixture of air and ozone, and then out through an outlet air conduit  34 . 
     Corona discharge ozone generators function better when supplied with relatively drier air. An air dryer generally designated  36  is included. In the disclosed embodiment, the air dryer  36  employs a desiccant  38  including silica gel. The desiccant  38  changes color from blue when new, to pink when the desiccant  38  requires replacement, and is visible through a window  40  ( FIG. 3 ). Relatively dryer air accordingly is supplied from the air dryer  36  to the ozone generator  30  via an inlet air conduit  42 . 
     Referring briefly to  FIG. 3 , which is a side view of the water treatment apparatus  20  with a top cover  44  in place, the air dryer  36  includes a cavity  46  ( FIG. 3 ) within a cavity body  48  ( FIG. 2 ) which receives a holder  50 . The holder  50  has two latch actuators  52  and  54 , and supports a removable and replaceable desiccant cartridge  56 . The desiccant cartridge  56  contains the actual desiccant  38 . The window  40 , through which the color of the desiccant  38  is observed, is in the top cover  44 . 
     Relatively dry air exits the desiccant cartridge  56  at the right side in the orientation of  FIG. 3 , to enter the inlet air conduit  42 . Ambient air enters the cavity  46  and then the desiccant cartridge  56  from outside the apparatus through cracks or small openings between the holder  60  and the cavity body  48 . The holder  50  thus does not have a tight fit. 
     Referring again to  FIGS. 1 and 2 , cold water flows from the water inlet  22  to the water outlet  24  through at least one water aspirator, generally designated  60 . The water aspirator  60  includes a conventional Venturi tube  62  which has a water inlet port  64 , an inlet cone  66  with a relatively greater angle, an outlet cone  68  with a relatively shallower angle, and a water outlet port  70 . As a result of increased water velocity immediately downstream of the inlet cone  66 , a vacuum is generated at a vacuum port  72 , which is employed to draw a gaseous mixture of air and ozone into water flowing through the aspirator  60 . 
     In the disclosed embodiment, there are two water aspirators, including respective first and second Venturi tubes. Thus, the aspirator  60  and its respective Venturi tube  62  are herein termed the first aspirator  60  and the first Venturi tube  62 . 
     A second water aspirator  80  includes a corresponding Venturi tube  82 , likewise having a water inlet port  84 , an inlet cone  86  with a relatively greater angle, an outlet cone  88  with a relatively shallower angle, a water outlet port  90 , and a vacuum port  92 . 
     The outlet air conduit  34  of the ozone generator  30  branches, at a “Y” connection  100 , into two separate conduits  102  and  104 . To ensure that water does not flow from the Venturi tubes  62  and  82  back into the ozone generator  30  via the conduits  102  and  104  and the outlet air conduit  34 , several check valves are provided. In particular, at the two vacuum ports  72  and  92  are a corresponding pair of primary check valves  106  and  108 . In addition, secondary check valves  110  and  112  are provided in the two conduits  102  and  104 . 
     A particular problem addressed by some embodiments of the invention is that different clothes washing machines have different water flow rates when filling. For example, a top load washer may require as much as forty gallons of water per load to fill, and fills at a relatively higher water flow rate. A front load washer requires typically fourteen gallons of water per load to fill, and typically fills at a relatively lower water flow rate. This difference in water fill rates has two consequences. First, a Venturi tube is designed for a particular minimum water flow rate threshold, below which the Venturi tube loses effect and essentially does not function. As a result, a Venturi tube designed for a top load washer with a relatively higher water fill rate may not function at all with a front load washer which draws water at a relatively lower fill rate. Second, if a Venturi tube is designed for the relatively lower fill rate of a front load washer, the Venturi tube does function at the relatively higher fill rate of a top load washer. The overall fill time is increased. The concentration of ozone is reduced, reducing the effectiveness of the ozonization during the actual agitation portion of a washing machine cycle. 
     In water treatment apparatus available to the prior invention, different models were available. A customer selected one model or the other depending on the type of washing machine. 
     Addressing this particular problem in a different way, the illustrated embodiment of the invention employs the first and the second water aspirators  60  and  80 , including respective first and second Venturi tubes  62  and  82 , which are designed for different flow rates. By way of example and not limitation, the first water aspirator  60  and Venturi tube  62  are designed for a relatively higher water flow rate of 2.3 gallons per minute. By way of example and not limitation, the second water aspirator  80  and Venturi tube  82  are designed for a relatively lower water flow rate of 1.3 gallons per minute. 2.3 gallons per minute is slightly less than the typical water fill rate of a top load washer, and 1.3 gallons per minute is slightly less than the typical water fill rate of a front load washer. 
     Downstream of the water aspirators  60  and  80  is an outlet manifold  120  having two inlets  122  and  124  connected to the two Venturi tube outlet ports  70  and  90 , respectively. The outlet manifold  120  has a manifold outlet  126  which is connected to a mixer, generally designated  130 . The mixer  130  accordingly is downstream of the two water aspirators  60  and  80 . The outlet manifold  120  is a molded plastic piece, and has a capped extension  128 , which is an artifact of the molding process. 
     In the illustrated embodiment, the mixer  130  includes a mixer input port  132  connected to the manifold outlet  126 , as well as a mixer output port  134 . The mixer  130  more particularly takes the form of a transparent outer tube  136  and a spiraled inner chamber  138  defined by a stationary helix  140 . Within the mixer  130 , gas (a mixture of air and ozone) is mixed and at least partially dissolved in water flowing through the apparatus  20  and being treated. During normal operation, bubbles are visible within the mixer  130  through the transparent tube  136 . 
     Referring briefly to  FIG. 4 , to facilitate viewing of bubbles within the mixer  130 , illumination is provided, as well as operational status of the apparatus  20  indicated, by a set of LEDs  150 , supported on a circuit board  152  mounted underneath the transparent outer tube  136 . Referring to  FIG. 5 , in addition to  FIG. 4 , a window  154  is provided in the top cover  44  for viewing the status LEDs  150 , as well as the bubbles within the mixer  130 . 
     The LEDs  150  more particularly are organized as five LED pairs  156 ,  158 ,  160 ,  162  and  164 . Each of the pairs includes a blue LED  166  and a red LED  168 . As described in greater detail hereinbelow, the blue LEDs  166  are energized to indicate normal operation, and the red LEDs  168  are energized to indicate a fault condition. 
     Referring again to  FIGS. 1 and 2 , connected to the mixer output port  134  is an input port  170  of a discharge manifold  172 . The discharge manifold  172  has two output ports  174  and  176 . 
     The output port  174  is the main output port, and corresponds to the water outlet  24  of the water treatment apparatus  20 , which water outlet  24  may be viewed as the main water outlet. The outlet port  176  corresponds to a secondary water outlet  178 , which has a cap  180 . The secondary water outlet  178  is provided in the event the water treatment apparatus  20  is to be used to provide ozonated water to something other than a washing machine connected to the main water outlet  24 . The water inlet  22 , the main water outlet  24 , and the secondary water outlet  178  all have threaded hose connections for apparatus  20  intended to be sold in the United States. 
     For selectively directing water from the water inlet  22  to the water outlet  24 , a single two-position valve  190  having three ports is provided. With reference to the rear view of  FIG. 6 , the valve  190  is operated via a slotted actuator  192  during initial setup employing, for example, an ordinary screwdriver. 
     In the illustrated embodiment, the valve  190  is connected to the input end of the water aspirators  60  and  80 . In other words, the valve  190  selectively connects the water inlet  22  two either the water inlet port  64  of the first Venturi tube  62  or the water inlet port  84  of the second Venturi tube  82 . More particularly, the valve  190  has an inlet port  194  connected to and supplied with water via the water inlet tube  26 , a first outlet port  196  connected to the water inlet port  84  of the second Venturi tube  82  via a coupler  198 , and a second outlet port  200  connected via a coupler  202  to a “U” tube  204 . The “U” tube  204  is in turn connected via a coupler  206  to the water inlet port  64  of the first Venturi tube  62 . The “U” tube  204  is a molded plastic piece and, like the discharge manifold  172 , has a capped extension  208  which is an artifact of the molding process. 
     It will, however, be appreciated that the function of selectively directing water from the water inlet  22  to the water outlet  24  through either of the water aspirators  60  and  80  can as well be accomplished by providing a valve (not shown) at the outlet ends of the two Venturi tubes  62  and  80 , and providing a simple manifold (not shown) at the input of the two Venturi tubes  62  and  82 . 
     In any event, during initial installation of the water treatment apparatus  20 , the valve  190  is set, employing the slotted actuator  192  ( FIG. 6 ), to direct water through either the first water aspirator  60  and Venturi tube  62 , or the second water aspirator  80  and Venturi tube  82 , depending upon the type of washing machine connected or to be connected to draw water from the water outlet  24 . Again, in the case of a top load washer, which has a relatively higher water fill rate, the valve  190  is set to direct water flow through the first water aspirator  60  and Venturi tube  62  (“TOP LOAD” position). In the case of a front load washer, having a relatively lower water fill rate, the valve  190  is set to direct water through the second water aspirator  80  and the second Venturi tube  82  (“FRONT LOAD” position). 
     Also visible in  FIG. 6  are the underside of the cavity body  48  of the air dryer  36 , as well as three hanger slots  212 . 
     In addition to the primary functional components described hereinabove, several additional components are shown in  FIGS. 1 and 2 . 
     For additional water conditioning, a magnetic water ionizer/descaler  210  is connected to the water inlet tube  26 , immediately downstream of the water inlet  24 . A controller, generally designated  214 , controls the ozone generator  30 , as well as the blue and red LEDs  166  and  168 . The controller  214 , in the illustrated embodiment, operates from 12 Volts DC, provided by an external power supply (not shown) connected via a power input connector  216  ( FIG. 2 ). 
     Referring now to  FIG. 7 , the controller  214  is supplied with 12 Volt D.C. power, and includes a printed circuit board (not shown) supporting a microcontroller  220 . The microcontroller  220  is programmed to effect various control functions, including functions represented by an “Ozone Generator Control Routine” represented by the flowchart of  FIG. 8 , and a “Failure Detect Routine” represented in the flowchart of  FIG. 9 . The controller  214  in general, and the microcontroller  220  in particular, control D.C. power provided to the ozone generator  30  via an output  222 . (The ozone generator  30  includes a conventional high voltage generator (not shown) which operates from 12 Volts D.C.) A current detector  224  measures current drawn by the ozone generator  30 . The controller  214  also includes outputs  226  and  228  for driving the BLUE  166  and RED 168 LEDs, respectively. 
     An aspect of the disclosed embodiment is the manner in which water flow is detected. In general (but with an exception described hereinbelow with reference to  FIG. 8 ), the ozone generator  30  is not supplied with power unless the washing machine is drawing water through the water outlet  24 . At other times, and in general, the ozone generator  30  is not energized. 
     Water flow is detected employing a microphone  230 , and associated control routines within the microcontroller  220 , which recognize a characteristic sound when water is being drawn and either of the two Venturi tubes  62  or  82  is operating. In the disclosed embodiment, a relatively simple approach is employed: When a sound having a frequency over 10 Hz is detected, it is assumed that one of the Venturi tubes  62  or  82  is operating A suitable microphone  230  is a Panasonic Model WM-60A electret condenser microphone. 
     To avoid possible corrosive effects of ozonated water, the microphone at  230  is connected to the inlet air conduit  42 . Although this particular location is somewhat removed from the Venturi tubes  62  and  82 , the characteristic sound travels through the apparatus  26 , in particular through the air outlet conduit  34  and the ozone generator  30 , and effectively reaches the microphone  230 . 
     Microphone  230  output is connected to a water flow detect input  232  of the controller  214 , and thereby to the microcontroller  220 . 
     Another aspect of the disclosed embodiment addresses the situation whereby, in many washing machines, at particular times during a washing machine cycle, water flow is pulsed ON and OFF briefly, for example five, ten or fifteen seconds at a time. Under such conditions, it is preferable for the ozone generator  30  to operate continuously, rather than for brief intervals. Thus, when the water stops flowing, the microcontroller  230  implements a timer, which allows the ozone generator  30  to remain powered ON for one minute, for example, before turning OFF. 
     There are two reasons for this. One reason is that ozone generation is not immediate; it may take several seconds for ozone to be generated after the ozone generator  30  is powered ON. Another reason is that the life of the ozone generator  30  is extended if the ozone generator  30  is allowed to operate continuously during such periods when water is drawn intermittently by the washing machine in a pulsed manner. 
     Accordingly, and with particular reference to the Ozone Generator Control Routine  240  of  FIG. 8 , decision box  242  determines whether water is flowing, again, via the detection (or not) of the characteristic sound of a Venturi tube operating. If water is flowing, then YES decision branch  244  is taken. 
     In box  246 , power to the ozone generator  30  is turned ON or, if already ON, is left ON. In box  248 , a TIMER FLAG is RESET. Thus, during portions of a washing machine cycle when water is drawn in intermittent pluses, the exemplary one-minute timer is reset each time water is drawn. The routine then exits at  250 . 
     If water is not flowing, then NO branch  252  is taken from decision box  242 . 
     Then, in decision box  254 , it is determined whether the ozone generator  30  is powered. If not, then NO branch  256  is taken, to exit at  250 . If the ozone generator power is ON, then YES branch  258  is taken. Decision box  260  then determines whether the TIMER FLAG is SET. If not, meaning water has just stopped being drawn from the outlet  24 , NO branch  262  is taken. In box  264 , the TIMER FLAG is SET. In box  266  a timer is started, by way of example, a one-minute timer. The routine then exits at  250 . 
     If in decision box  260  it is determined that the TIMER FLAG is already SET, meaning water has recently stopped being drawn from the outlet  24  (“recently” meaning less than one minute prior), then YES branch  268  is taken. 
     Another decision box  270  then checks the timer to determine whether the exemplary one-minute time has elapsed. If not, then NO branch  272  is taken, and the routine then exits at  250 . 
     If the exemplary one-minute time has elapsed, then YES branch  274  is taken. In box  276 , power to the ozone generator  30  is turned OFF. The routine then exits at  250 . 
     As another aspect of the disclosed embodiment, the current detector  224  is employed to determine whether the ozone generator  30  is operating properly. During normal operation, current drawn by the ozone generator  30  is within the approximate range 0.8 amperes to 2.0 amperes. If current drawn by the ozone generator  30  is above a predetermined maximum value, for example above 2.0 amperes, or below a predetermined minimum value, for example below 0.8 amperes, such indicates that the ozone generator  30  has failed. 
     If the ozone generator is operating normally (regardless of whether water is currently flowing), then normal operation is indicated, and the blue LEDs  166  are operated. If, on the other hand, current drawn by the ozone generator is above the predetermined maximum value (2.0 amperes in the illustrated embodiment) or below the predetermined maximum value (0.8 amperes in the illustrated embodiment), then the red LEDs  168  are operated, indicating to a customer that a failure has occurred. To particularly draw attention, the red LEDs  168  may be operated in a flashing manner. 
     With particular reference to an ozone generator Failure Detect Routine  280  of  FIG. 9 , in decision box  282  it is determined whether the ozone generator  30  is powered ON. If not, then NO branch  284  is taken, and the routine exits at  288 . 
     If in decision box  282  it is determined that the ozone generator  30  is powered ON, then YES branch  290  is taken, and execution passes to decision box  292 . If in decision box  292  it is determined that current, as detected by the current detector  224  is within the predetermined limits, then YES branch  294  is taken, to box  286 , where the BLUE LEDs  166  are driven. 
     If, on the other hand, in decision box  292  is it is determined that current is not within limits, then NO branch  296  is taken. In box  298  the RED LEDs  168  are driven. To particularly draw attention, the red LEDs  168  may be driven to flash. The routine then exits at  288 . 
     While a specific embodiment of the invention has been illustrated and described herein, it is realized that numerous modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention.