Abstract:
Water treatment apparatus including an elongated first water chamber, an inlet for water at one end of the chamber, an outlet for water at the opposite end of the chamber and at least one ultraviolet lamp within and extending longitudinally of the chamber. The chamber may be connected to a second chamber into which air and/or ozone may be introduced through outlets for flow through the second chamber. Alternatively, the first chamber may comprise a chamber which contains the air and/or ozone outlets. A funnel shaped member is provided at the upper end of the first or second chamber to collect bubbles carrying impurities in the water to the surface.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a divisional of U.S. application Ser. No. 10/487,210 filed Nov. 28, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to water treatment apparatus typically for use in aquaculture systems but also suitable for use in other applications.  
         [0003]     Aquaculture has commonly been conducted by growing fish, prawns and other marine invertebrates in outdoor ponds. The ponds however eventually become polluted because faeces, uneaten food and algae work their way to the bottom of the ponds. This makes the ponds almost impossible to clean. In addition large quantities of valuable water are required to keep these systems functional. Other disadvantages are also associated with outdoor aquaculture systems. For example pests can eat stock, adverse weather conditions such as floods can cause stock loss by washing the stock away and very hot weather can cause growth of algal blooms which can kill the stock. In addition in very hot or very cold weather, the stock will stop growing. Muddy waters or disturbed water can also cause the stock to have an unpalatable taste.  
         [0004]     In order to overcome the above disadvantages, indoor commercial aquaculture systems were introduced where fish or other marine invertebrates are grown in tanks placed in large buildings or sheds.  
         [0005]     A disadvantage of the known systems is that the buildings or sheds housing the aquaculture system resemble a maze of pipes and plumbing as water is pumped between the system components such as tanks, filters, biological filters, foam fractionators, ultraviolet water treatment units and other water treatment components. These components are individual components which have to be set up in different parts of the building.  
         [0006]     With regards to the individual components, if ultraviolet water treatment units are installed, they are installed into the main water flow pump line which reduces flow thus increasing the electricity consumption. In the foam skimmers or foam fractionators which are used in the conventional systems, insufficient bubbles or foam are created or forced out of the top of the units. If insufficient bubbles or foam are created, the fractionators simply do not function. To make them function correctly, high pressure high energy pumps fitted with air venturis are employed but these do not always overcome the problem of inefficient operation.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention aims to provide improved water treatment apparatus typically for use in aquaculture systems but also suitable for use in other applications. Other objects and advantages of the invention will become apparent from the following description.  
         [0008]     The present invention thus provides in a first preferred aspect water treatment apparatus comprising:  
         [0009]     an elongated first water treatment chamber,  
         [0010]     an inlet for water to be treated at one end of said chamber,  
         [0011]     an outlet for treated water at the opposite end of said chamber, and  
         [0012]     at least one elongated ultraviolet lamp, said lamp extending longitudinally within said chamber wherein water flowing through said chamber from said inlet to said outlet is exposed to ultraviolet light from said lamp.  
         [0013]     Preferably, the first water chamber is arranged in a substantially upright attitude with the one end of said chamber comprises a lower end of the chamber and the opposite end of said chamber comprising an upper end of said chamber. The apparatus may also include a second water chamber with the outlet from the first chamber being connected to an inlet to the second chamber with means for exposing water in the second chamber to ozone and/or air.  
         [0014]     Preferably the second chamber is disposed in a substantially upright attitude and the inlet to the second chamber is disposed at an upper end of the second chamber and the second chamber having an outlet at a lower end thereof. An ozone and/or air outlet or outlets are suitably provided at the lower end of the second chamber for supplying ozone and/or air to the chamber for the passage of ozone and/or air through water in the second chamber.  
         [0015]     An air pump may be connected to the air outlet or outlets.  
         [0016]     An ozone reactor or generator may be provided externally of the second chamber, the ozone reactor or generator being connected to the ozone outlet or outlets.  
         [0017]     Collecting means may be provided at the upper end of the second chamber for collecting foam at or adjacent the surface of water therein and a waste outlet is connected to the collecting means. The collecting means may comprise a conical member or funnel. A float may be provided for supporting the conical member at or adjacent the surface of water.  
         [0018]     The water treatment apparatus may be used in combination with a reservoir for containing water to be treated, the inlet to the first chamber and the outlet from the second chamber being connected to the reservoir.  
         [0019]     Means such as an air supply may be associated with the second chamber outlet for assisting flow of water from the second chamber into the reservoir.  
         [0020]     In an alternative arrangement, the first chamber may include the means for exposing water in the chamber to ozone and/or air and the second chamber is not required. Thus an ozone and/or air outlet or outlets may be provided at the lower end of the first chamber for supplying ozone and/or air to the chamber for the passage of ozone and/or air through water in the chamber.  
         [0021]     As above an air pump may be connected to the air outlet or outlets. Suitably also an ozone reactor or generator may be provided externally of the first chamber, the ozone reactor or generator being connected to the ozone outlet or outlets.  
         [0022]     The first chamber may include collecting means at its upper end for collecting foam at or adjacent the surface of water therein and a waste outlet is connected to the collecting means. The collecting means may comprise a conical member or funnel and may have an upper edge over which foam flows for collection. The conical member or funnel may be adjustably supported for height variations within the chamber of the foam fractionator. Alternatively, and as referred to, the funnel member may be supported by a float or floats at or adjacent the level of water in the foam fractionator chamber.  
         [0023]     The ultraviolet light source is suitably arranged centrally in the first chamber. A plurality of ultraviolet light sources may be provided. The ultraviolet light sources may be arranged circumferentially in the chamber.  
         [0024]     The first chamber may be used in combination with a reservoir for containing water to be treated with the inlet and outlet from the first chamber being connected to the reservoir. Means such as an air supply may be associated with the outlet for assisting flow of water from the first chamber into the reservoir.  
         [0025]     The outlet may communicate with the reservoir through a return line. Air may be supplied to the return line to assist in water flow back to the main chamber. The return line suitably includes a portion within the main chamber which extends in a direction to assist in circulating flow of water in the main chamber. The return line portion in the main chamber may be apertured to allow controlled escape of air in the form of bubbles from the return line.  
         [0026]     In another aspect, the present invention provides water treatment apparatus for treating water in a reservoir, said water treatment apparatus comprising: 
        a substantially upright elongated first water treatment chamber, an inlet for water to be treated at a lower end of said chamber, first connecting means for connecting said inlet to said reservoir, an outlet at the upper end of said first chamber, at least one elongated ultraviolet lamp, said lamp extending longitudinally within said first chamber,     a substantially upright second water chamber, said outlet from said first chamber being connected to an inlet to said second chamber at an upper end of said second chamber,     an ozone and/or air outlet or outlets at the lower end of said second chamber for supplying ozone and/or air to said chamber for the passage of ozone and/or air through water in said second chamber,     collecting means at the upper end of said second chamber for collecting foam at or adjacent the surface of water therein created by air and/or ozone passing through said second chamber,     a waste outlet connected to said collecting means,     an outlet for treated water at a lower end of said second chamber, and second     connecting means for connecting said outlet of said second chamber to said reservoir for returning treated water to said reservoir.        
 
         [0034]     The second connecting means suitably returns treated water from the second chamber to the reservoir at a position above the inlet to the first chamber. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]     In order that the invention may be more readily understood and put into practical effect reference will now be may to the company drawings which illustrate the preferred embodiments of the invention and wherein:  
         [0036]      FIG. 1  illustrates in perspective view, a building module defining an aquaculture system incorporating water treatment apparatus according to a first embodiment of the present invention;  
         [0037]      FIG. 2  is a sectional elevational view of the building of  FIG. 1 ;  
         [0038]      FIG. 3  is a sectional plan view of the building of  FIG. 1 ;  
         [0039]      FIG. 4  illustrates the building of  FIG. 1  with the end flaps open;  
         [0040]      FIG. 5  illustrates the layout of the plumbing pipes of the system incorporated in the base or foundation of the building module;  
         [0041]      FIG. 6  illustrates in sectional view the water treatment apparatus comprising a foam fractionator and associated ultraviolet and ozone generator units as used in the system of FIGS.  1  to  4 ; and  
         [0042]      FIGS. 7 and 8  illustrate in sectional view further forms of water treatment apparatus for use in the aquaculture systems. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0043]     Referring to the drawings and firstly to FIGS.  1  to  4 , there is illustrated an aquaculture system  10  in the form of a modular building  11  comprising and defining a main chamber  12  for holding fish or marine invertebrates, a swirl chamber  13  which serves as a primary filter and a biological filter-drum or screen filter chamber  14  of a secondary filter. The chambers  12 ,  13  and  14  have their bases at substantially at the same level however the water level in each chamber is controlled such that the level in chamber  14  is less than the level in chamber  13  and the level in chamber  13  is less than the level in chamber  12 . This then allows flow of water from the main chamber to the swirl chamber  13  and then to the chamber  14  under the influence of gravity without pumping. The building module  11  also defines a biological filter tank  15  which is elevated and located above the main chamber  12 . Opposite end integral hip roof and wall sections  16  and  17  extend from opposite sides of the tank  15  and over the main chamber  12  and swirl chamber  13  and filter chamber  14  respectively to define enclosed air spaces over the main chamber  12  and chambers  13  and  14 .  
         [0044]     The building  11  may be constructed of any suitable materials such as steel, timber, fiberglass or any other mouldable materials, or any other materials however the preferred material of construction is concrete suitably a concrete which is waterproof and provides sufficient strength to the building  11  and additionally has high insulation properties such that no additional insulation is required and further facilitates moulding of the tank  12  and chambers  13 , 14  and  15 . The main chamber  12  and chambers  13  and  14  may be formed as one moulding indicated generally at  18 , and the tank  15 , and roof and wall sections  16  and  17  as separate mouldings which are then assembled and jointed to the lower moulding  18 . Opposite end walls of the tank  15  and roof and wall sections  16  and  17  are thus aligned with the opposite side walls of the moulding  18  and the outer ends walls of the roof and wall sections  16  and  17  are aligned with opposite end walls of the moulding  18 . The opposite end walls of the roof and wall sections  16  and  17  are closed by hinged panels  19  which may be pivoted upwardly as shown in  FIG. 4  to provide access at one end to the chamber  12  or at the other end to the chambers  13  and  14 . The biological filter tank  15  is also closed by upper lid panels  20  which are hingedly mounted by central hinges  21  to enable them to be lifted to provide access to the interior of the tank  15 . It will be apparent that when they panels  19  are closed, the building  11  defines a fully enclosed air space over the chambers which facilitates control of air and water temperature.  
         [0045]     The main chamber  12  is of a generally rectangular or square configuration with the corners thereof being truncated as at  22 . A spillway  23  is provided on one side of the chamber  12  and at an elevated location to convey water in the chamber  12  above the level of the spillway  23  into the swirl chamber  13 . This acts as a skimmer to remove any floating scum or other materials from the surface of the water in the chamber  12 . A screen  24  of mesh-like form is provided across the spillway  23  to prevent fish from escaping from the main chamber  12  into the swirl chamber  13 . The main chamber  12  also includes a central drain outlet  25  with which communicates through a passage  26  with the periphery of the base of the swirl chamber  13  at  27  which directs water from the chamber  12  into the chamber  13  in a generally circumferential direction such as to effect anti-clockwise swirling motion of water in the chamber  13 . The passage  26  carries fish and food waste from the main chamber  12  into the swirl chamber  13  without the use of pumping equipment which may breakup particles within the chamber  12 . The passage  26  may also have a branch line  28  through which water may be drained from the chamber  12  under the control of a valve  29  externally of the building module  10  (see  FIG. 5 ).  
         [0046]     The main chamber  12  also includes in the outer pair of truncated corners  22 , a pair of foam fractionators  30  for oxygenating and cleaning the water in the main chamber  12 . Associated with each foam fractionator  30  is an ultraviolet unit  31  for killing pathogens in the water and one or more ozone reactor or generator units  32  for introducing ozone into the water in the fractionator  30  for sterilizing the water. The foam fractionator  30  as more clearly shown in  FIG. 6  includes a chamber  33  moulded or incorporated into a corner section  22  in an upright attitude. The chamber  33  may be formed by a tubular pipe  34  having an upper end which extends above the corner  22  and which is closed by a removable cap  35 . A return line  36  connected to the bottom of the chamber  33  extends upwardly and then through the wall of the chamber  12  and terminates in an outward flow duct  37  (see also  FIG. 2 ) which extends in a generally circumferential direction relative to the tank  12 . An air inlet  38  into the return line  36  at the lower end thereof directs a flow of air into the line  36  to assist in the flow of water back into the chamber  12 . The duct  37  may be apertured to allow controlled escape of air into the chamber  12  in the form of air bubbles.  
         [0047]     The chamber  33  communicates with the main chamber  12  via the ultraviolet unit  31  which has a chamber  39  which may also be defined by a tubular pipe  40  and which houses an elongated ultraviolet light source  41  in the form of an ultraviolet lamp which is removably mounted in the chamber  39  by means of an end cap  42  engaged with the upper end of the pipe  40 . A duct  43  communicates an outlet at the lower end of the chamber  39  with the main chamber  12  and a further duct  44  communicates the upper end of the chamber  39  with the chamber  34 . Thus the level of water in the chambers  33  and  39  is the same as the level of water in the chamber  12  and water before passing into the chamber  33  is exposed to ultraviolet light.  
         [0048]     The ozone generator unit  32  also includes a chamber  45  which is also defined by a tubular pipe  46  located in an upstanding attitude in a tank corner  22  and which houses an ozone reactor or generator  47 . An outlet duct  48  passes upwardly from the bottom of the chamber  45  and then downwardly in the chamber  33  to terminate in an air stone  49  to inject ozone into the water in the chamber  33  for passage as bubbles upwardly through water in the chamber  33  to expose the water therein to ozone.  
         [0049]     A drain cone or funnel  50  is provided in the chamber  33  and is connected to a drain pipe  51  which leads outwardly through a side wall of the chamber  33  to waste or for collection in a container if desired. Air for creating bubbles in the chamber  33  is supplied to the lower end of the chamber  33  to air stones  52  which are suspended via air supply ducts  53  connected to an air supply manifold  54  above the chamber  33 . Air is supplied to the air manifolds  54  via piping  55  in the slab of the building  11  (see  FIG. 5 ) connected to an air pump  56  in the air space in the building module  11  within the roof and wall section  17  (see  FIG. 2 ).  
         [0050]     Thus water for treatment in the chamber  33  initially passes via duct  43  through the ultraviolet chamber  39  where it is exposed to ultraviolet light from the generator  41  which will destroy pathogens in the water and then the water passes through the duct  44  into the chamber  33 . Air supplied to the air stones  52  via the ducts  53  exits as bubbles in the water which pass upwardly through the chamber  33  against the flow of water circulating through the chamber  33  in the opposite direction for flow through the return line  36  back to the chamber  12 . Bubbles passing upwardly through the chamber  34  carry dirt and fat particles or other impurities in the water to the surface. In addition, the ozone reactor or generator unit  32  creates bubbles of ozone which also pass upwardly through the chamber  33  to sterilize and clean the water.  
         [0051]     Bubbles upon reaching the surface of the water will froth up and create foam which flows over the upper edge of and into the drain funnel  50  carrying the dirt and fat particles through the drain pipe  51  to waste. The height of the drain funnel  50  can be adjusted to vary the extent to which bubbles are discharged and for this purpose may be supported adjustably on brackets  57 . Alternatively, the drain funnel  50  may be attached to floats  58  to support the funnel  50  at or adjacent the level of water within the chamber  33 . The foam is thus collected just above the water level and flows out through the funnel  50  under the influence of gravity. Water flowing outwardly from the chamber  33  and into the chamber  12  via the duct  36  and duct  37  creates a circulating flow of water in the tank  12  in an anti-clockwise direction ( FIG. 3 ).  
         [0052]     As the system  10  operates under low pressure, the foam fractionator  30  can be cleaned without stopping operation of the system  10  and similarly, the ultraviolet light generators  41  can also be removed for replacement of lamps, bulbs or repair whilst the system  10  continues to run. The ozone generator unit  32  can also be serviced whilst the system is operating. This is facilitated by having the foam fractionator  30 , ultraviolet unit  31  and ozone generator unit  32  arranged to one side of the chamber  12  in a truncated corner  22  or a wall of the chamber  12  and thus out of the main flow of water.  
         [0053]     Referring now to  FIG. 7 , there is illustrated a further embodiment of foam fractionator  69 . In this case, the separate ultraviolet chamber  39  of the embodiment of  FIG. 6  is eliminated and the ultraviolet light generators  41  provided as a single tube set or a multiple tube set arranged circumferentially about the funnel  50 . The chamber  70  of the foam fractionator  69  communicates through upper and lower ducts  71  and  72  with the main chamber  12 .  
         [0054]     In the configuration of  FIG. 8 , the foam fractionator  73  has a foam collector  74  which is in the form of an inverted cone which is located around the sides of the fractionator chamber  75  so that the foam  76  is collected around the outer sides of the chamber  75 . Multiple outlets  77  are provided to direct the collected foam  76  outwardly of the chamber  75  to waste. The foam collector  74  surrounds a central ultraviolet light generator  41  which kills pathogens and bacteria in the water. It will be noted that in this embodiment, a submersible pump  78  is provided in the chamber  75  to assist in flow of water back into the main chamber  12  through duct  79  whilst water for treatment flows from the upper portion of the chamber  12  into the chamber  75  through duct  80 .  
         [0055]     As in the embodiment of  FIG. 6 , an air stone or stones  52  are provided at the lower end of the chambers  70  or  75  to serve as an outlet or outlets for ozone and/or air for bubbling through the water in the chambers  70  and  75 .  
         [0056]     The described water treatment apparatus may be employed in aquaculture systems other than aquaculture systems described above or in any other water treatment applications. Furthermore the separate components of the described water treatment apparatus may be used individually or separately.