Abstract:
Apparatus for injecting ozone into the return line of a filtration system used in conjunction with a tank of water incorporates a check valve in a suction line for an ozone generator providing the ozone. Flow of water through the conduit providing ozone from the ozone generator is precluded by the check valve establishing a pressure environment within the conduit to prevent the flow of water from reaching the ozone generator. As the check valve is in an atmospheric environment, it is unlikely to deteriorate or be damaged by the air flowing therethrough into the ozone generator and its integrity is preserved.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application relates to subject matter described in and claims priority to a provisional application entitled “Ozone Generator Backflow Prevention”, assigned Serial No. 60/411,614 and assigned a filing date of Sep. 18, 2002 and describing an invention made by the present inventor. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    An ozone generator provides ozone (O 3 ) as a gas to be used for various purposes. The ozone may be used as an oxidizing agent to oxidize organic materials. It is commonly used as a bactericide and as a viricide to be mixed with a liquid, to sterilize devices, and in other environments to help reduce spread of disease. Thus, it is used in various industries as an oxidizer, bactericide and/or viricide. Pools and spas are widely used in both public and private locations and do serve as a transmissive medium for various diseases and cause or exacerbate the spread of disease and/or infections to user&#39;s of pools and/or spas. Chlorine is a commonly used chemical for pools and spas to prevent the spread of disease. However, unless the chlorine level is meticulously maintained, especially during periods of high use or when the temperature of the water is raised by the environment or through use of heaters, its effectiveness is compromised.  
           [0003]    To aid in preventing the spread of disease, particularly in pools and spas, an ozone generator may be incorporated to inject ozone into filtered water being returned to the pool or spa. The conduit conveying the ozone includes a check valve to prevent backflow of the pool water, which backflow will tend to destroy the apparatus generating the ozone. Unfortunately, the presence of ozone in and about the check valve creates nitric acid and various salts that may cause damage to the check valve or clog it. In either event, the check valve either becomes useless for its intended function or may prevent flow of ozone therethrough.  
         SUMMARY OF THE INVENTION  
         [0004]    An ozone generator provides ozone for injection into filtered water being returned to a pool or spa. The ozone generator includes a low pressure or suction line for drawing in air to be ozonated. A check valve is placed in the suction line to develop a closed gaseous environment to prevent outflow of water from the pool or spa to the ozone generator. Through such placement, the check valve tends to have a relatively long useful life as it is only subjected to a flow of air therethrough.  
           [0005]    It is therefore a primary object of the present invention is to provide a check valve in an atmospheric environment and operating in conjunction with an ozone generator to ensure against drainage of water from a pool or spa therethrough.  
           [0006]    Another object of the present invention is to provide a check valve and ozone generator used in conjunction with a pool or spa to prevent water drainage by not subjecting the check valve to the corrosive effects of ozone.  
           [0007]    Still another object of the present invention is to provide a check valve for preventing drainage of water from a pool or spa that is in an environment which will ensure a long life of the check valve.  
           [0008]    Yet another object of the present invention is to provide an ozone generator to inject ozone into a pool or spa and a check valve disposed upstream of the ozone generator for preventing drainage of water through the ozone generator.  
           [0009]    A further object of the present invention is to provide an ozone generator for injecting ozone into a pool or spa which is downstream from a check valve and prevents drainage of water from the pool or spa.  
           [0010]    A still further object of the present invention is to provide a method for injecting ozone into a pool or spa while preserving the integrity of a check valve preventing unwanted water drainage.  
           [0011]    A yet further object of the present invention is to provide a check valve upstream of an ozone generator to prevent contact by the ozone generated with the check valve to preserve the integrity of the check valve.  
           [0012]    These and other objects of the present invention will become apparent to those skilled in the art as the description there proceeds.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:  
         [0014]    [0014]FIG. 1 illustrates prior art apparatus for injecting ozone from an ozone generator into a pool or spa; and  
         [0015]    [0015]FIG. 2 illustrates apparatus for eliminating an ozone enriched environment in proximity with a check valve used to prevent water drainage from a pool or spa.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]    [0016]FIG. 1 illustrates a prior art system  10  for injecting ozone into a tank  12 , which may be a pool, a spa, a water storage tank or other depository for water  14 . A conventional filtration apparatus  16  filters water drawn from tank  12  through conduits  15 ,  17 , as depicted by arrows  18 ,  20 . The flow of water is urged and controlled by a circulation pump  22 . The water outflow from the pump is through a conduit  24  to a venturi  26  and into the tank through a further conduit  28 . An ozone generator  30 , which may be any of many commercially available ozone generators, generates a flow of ozone conveyed by a conduit  32  through a check valve  34 . A conduit  36  conveys the outflow from the check valve to inlet  38  of venturi  26 . The flow of water from conduit  24  through the venturi creates a low pressure environment to draw the ozone from inlet  38  and entrain the ozone in the water exhausted from the venturi into conduit  28 . Thereby, the water returned to tank  12  is ozone enriched. As is well known, the presence of ozone within tank  12  will serve in the manner of an oxidizer to break down organic material and it will serve in the manner of both a bactericide and a viricide to minimize contamination of water  14  by bacteria and viruses.  
         [0017]    When circulation pump  24  is not operating, there may be a tendency for water to drain from tank  12  into conduit  28  and through venturi  26  into conduit  36 . Check valve  34  prevents further drainage of the water through conduit  32  to protect ozone generator  30 . Additionally, conduit  32  includes a loop section  40  having its highest point above level  42  of water  14 . Thereby, force of gravity prevents any water within conduit  32  from flowing past loop  40 . Thus, ozone generator  30  is protected against damage due to water flowing thereinto. Furthermore, loss of water from tank  12  is prevented.  
         [0018]    One of the problems with prior art system  10  shown in FIG. 1 relates to check valve  34 . Ozone flowing therethrough is an oxidizing agent and may cause damage to one or more components of the check valve due to oxidation. Additionally, the presence of ozone in the water at the upstream end of the check valve will produce nitric acid. This nitric acid will have a tendency to cause corrosion and other damage to one or more components of the check valve. Various salts may also be produced. Deposit of these salts on one or more components of the check valve may impact the operation of the check valve to the extent that it may no longer preclude waterflow therethrough. Alternatively, the check valve may become clogged and prevent further flow of ozone therethrough. These problems are experienced daily wherein prior art system  10  is installed. Sometimes loop  40  is not installed or is installed incorrectly, whereby it will no longer function as intended. Moreover, pressure waves within tank  12  may cause water to flow through the loop and thereafter it serves as a siphon to drain the water.  
         [0019]    Referring to FIG. 2, a solution to the problems presented by prior art system  10  will be described. For the sake of clarity, elements common to prior art system  10  will be given the same reference numerals.  
         [0020]    Apertures  50 , forming the system shown in FIG. 2, is or may be identical to prior art system  10  with respect to tank  12 , filter  16 , pump  22  and the interconnecting conduits. A commercially available ozone generator  30  is adapted to include an inlet line or suction line  52  conveying air into the ozone generator. The ozone generated is exhausted into conduit  32 , via loop  40  and into inlet  38  of a venturi  26 . The purpose of the venturi is that of entraining ozone in the water flowing into tank  12  (typically a spa). Accordingly, the venturi shown in FIG. 2 could be replaced by a sparger or other device for entraining the ozone in the water flowing into the tank. A check valve  54  is mounted in suction line  52  to prevent backflow of air through the suction line. It is to be noted that suction line  52  downstream of check valve  54 , ozone generator  30  and conduit  32  define a closed system having an inlet at the check valve and an outlet at inlet  32  of venturi  26 . Check valve  54  is a commercially available check valve for limiting flow of a gas, air in the present case, only in one direction. In this case, air flows through check valve  54  only into suction line  52  and flow from the suction line through the check valve to the atmosphere is prevented by operation of the check valve. As this check valve is only subjected to an environment of air, it will not be subjected to the potential deterioration and damage to which check valve  34  in prior art system  10  is subjected. Check valve  54  operates in a relatively benign environment and it is well known to those skilled in the art how to construct check valves having a long operating life in such environments.  
         [0021]    In the event circulation pump  22  ceases to operate and water  14  within tank  12  begins to drain through conduit  28 , it may tend to flow into conduit  32  via venturi  26 . As there is no airflow out of suction line  52  due to the operation of check valve  54 , any water flowing into conduit  32  will be resisted by a commensurate pressure build up within the conduit. Thus, water flow into conduit  32  from inlet  38  of venturi  26  will only occur to a very limited extent until the respective pressures equalize. As discussed above, loop  40 , being higher than water level  42  in tank  12  incorporates the force of gravity to prevent water flow past the loop. However, even in the absence of loop  40 , the pressure build up within conduit  32  would prevent all but a minimal flow of water into conduit  32  and none of the water would reach ozone generator  30 .  
         [0022]    At some installations of spas, there may be a bubbling or “burping” by the ozone entrained in the water flowing thereinto. Such bubbling may be unpleasant or distracting to an occupant of the spa. To prevent such bubbling, a valve  55  may be placed upstream of check valve  54  to adjust the rate of airflow into the ozone generator and thereby control the rate of outflow of ozone from the ozone generator and into the spa. Additionally, valve  55  may incorporate one or more filter elements to filter the air flowing into suction line  52 ; alternatively, such a filter may be displaced from valve  55 .  
         [0023]    In conclusion, backflow of water to the ozone generator in apparatus  50  is primarily prevented by check valve  54  which creates a gaseous pressure environment within conduit  32 . Additionally, as the check valve operates completely within an atmospheric environment, it is unlikely to deteriorate or be damaged by the air flowing therethrough and its proper operation for a long period of time can be expected. Thus, the present invention provides substantial benefits not present in nor available from prior art systems for introducing ozone into a tank of water.