Patent Publication Number: US-2005127311-A1

Title: Fluid release system

Description:
FIELD OF THE INVENTION  
      The invention relates to a fluid release system and to a valve that can be used in a fluid release system. More particularly, the present invention relates to a fluid release system such as a drainage system for a vessel containing fluids under pressure such as in an evaporative air conditioner.  
     BACKGROUND OF THE INVENTION  
      In particular applications, it is desirable for vessels in one operating state to contain fluids and in another operating state for the fluids to be removed or released from the vessel. One known solution to remove fluids in liquid form from vessels is to allow the vessels to be drained of the liquids contained within the vessel by an operator having to manually actuate a drainage valve.  
      An example of a vessel which contains/utilises liquids in one operating state while requiring that they be removed in another operating state is an evaporative air conditioner. Evaporative air conditioners, which are also known in the art as ‘water cooled air conditioners’, are predominantly used in climates where relatively dry conditions are experienced. They usually comprise a frame structure defining a chamber that is surrounded by absorbent walls. In use, a water distribution system at mains pressure introduces water over the water absorbent walls and a fan assembly introduces air into the cavity so that dry air passes through the water absorbent walls and humidifies (and thereby cools) the air. The cooled humidified air is blown from an air outlet through to a dwelling in operation.  
      Legionnaires&#39; disease (Legionellosis) is a serious and sometimes fatal form of pneumonia. Legionnaires&#39; disease is caused by infection with Legionella bacteria. Although not all cases of Legionnaires&#39; disease are severe, it can be fatal. People usually get Legionnaires&#39; disease by breathing in Legionella bacteria in very fine droplets of water called aerosols.  
      Legionella bacteria thrive in warm water and warm damp places such as within evaporative air conditioning units, which can provide environments that let Legionella bacteria increase to large numbers. Legionella can be spread in the humidified air during operation of the evaporative air conditioner. It is therefore highly desirably to ensure that all water is drained from evaporative air conditioner reservoirs when the evaporative air conditioners are switched off.  
      The valves should be properly operated to ensure that the water in the evaporative air conditioner drains properly and secondly, the valve must be able to close properly in relatively harsh environments.  
      One known drain valve used in evaporative air conditioners requires manual actuation of the drain valve to ensure drainage of all liquids from the air conditioner chamber in use.  
     SUMMARY OF THE INVENTION  
      According to a broad aspect of the invention, there is provided a fluid release system comprising: 
          an apparatus that utilises fluid under pressure in operation;     a control means adapted to control the supply of fluid under pressure to said apparatus;     a fluid containment reservoir adapted to contain fluid utilised by said apparatus in operation;     a fluid release outlet provided in said fluid containment reservoir, said fluid release outlet being adapted to allow fluid to be released from said fluid containment reservoir;     a valve operatively associated with said fluid release outlet, said valve being adapted to be opened to allow flow of said fluid from said fluid containment reservoir to said fluid release outlet,     a pressure operated valve closure means to close said valve in use;     wherein in use, said pressure operated valve closure means is connected to a source of said fluid under pressure in operation of said apparatus to thereby close said valve.        

      Preferably, operation of the control means to supply fluid to said fluid containment reservoir causes fluid under pressure to close said pressure operated valve closure means.  
      In one embodiment, the fluid release system further comprises: 
          a fluid inlet conduit adapted to supply fluid under pressure to said fluid containment reservoir; and     a bleed conduit extends from said fluid inlet conduit to said valve closure means such that in operation of the control means to supply fluid under pressure through the fluid inlet conduit to the fluid containment reservoir causes the fluid under pressure to flow through the bleed conduit to the valve closure means to thereby close the valve. Advantageously, the valve comprises a valve body having a base portion and a cap portion. The pressure operated valve closure means optionally includes:     a flexible diaphragm separating said base portion from said cap portion; and     a pressure chamber defined between said diaphragm and said cap portion,     wherein said pressure chamber is adapted to be connected to said source of said fluid under pressure to thereby cause said diaphragm to flex in the direction of the base portion.        

      The valve may comprise: 
          a fluid chamber defined between said diaphragm and said base portion;     a valve inlet extending through said base portion into said fluid chamber;     a valve outlet extending through said base portion into said fluid chamber; and     a valve seat provided in said fluid chamber, said valve seat having a valve conduit extending therein for passage of fluid from said fluid chamber to said valve outlet in use.        

      The valve seat may have a contoured surface substantially opposite to said diaphragm, and 
          wherein in use said source of said fluid under pressure flexes said diaphragm causing it to align with said contoured surface and thereby prevent flow of fluid through said valve conduit.        

      A cap conduit may be provided in said cap portion to allow said fluid under pressure to enter said pressure chamber in use.  
      The source of fluid under pressure may be provided to said cap conduit by said control means.  
      Optionally, said control means comprises: 
          a fluid inlet valve provided in said fluid inlet conduit connected to said apparatus, wherein said fluid inlet valve is adapted to be opened to allow fluid to flow in said fluid inlet conduit.        

      A bleed conduit may connect said fluid inlet conduit and said cap conduit.  
      The apparatus is in one embodiment of the invention, an evaporative cooler and said fluid is water.  
      According to another broad aspect of the invention, there is provided a valve comprising: 
          a valve body having a base portion and a cap portion;     a flexible diaphragm separating the base portion from the cap portion;     a pressure chamber defined between said diaphragm and said cap portion, said pressure chamber being adapted in use to be connected to a source of fluid under pressure adapted to cause said diaphragm to flex in the direction of the base portion;     a fluid chamber defined between said diaphragm and said base portion;     a valve inlet extending through said base portion into said fluid chamber;     said base portion having a generally concave inner surface;     a valve outlet extending through said concave inner surface of said base portion;     wherein said generally concave inner surface is shaped such that upon flexure of said diaphragm under the influence of fluid under pressure, said flexed diaphragm will make contact with and seal against said concave inner surface to thereby prevent flow of fluid through either said valve inlet or said valve outlet, or both.        

      A cap conduit may be provided in said cap portion to allow said fluid under pressure to enter said pressure chamber in use.  
      The flexible diaphragm may be layered between said cap portion and said base portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      An embodiment of the present invention will now be described by way of example only, with reference to the accompanying drawings in which:  
       FIG. 1  illustrates a cross-sectional view of a drain valve used in the drainage system of an evaporative cooler in an open position;  
       FIG. 2  illustrates cross-sectional view of the drain valve of  FIG. 1  in a closed position;  
       FIG. 3  is a schematic diagram of a drainage system for an evaporative cooler using the drain valves shown in  FIG. 1  and  FIG. 2  according to an embodiment of the invention;  
       FIG. 4   a  shows a cross sectional view through a base portion of a valve according to another preferred embodiment;  
       FIG. 4   b  shows a side view exploded view of a cap and diaphragm that are attached to the base of  FIG. 4   a  when assembled;  
       FIG. 5  shows a top view of the cap of  FIG. 4   b;    
       FIG. 6  shows a cross-sectional view of the cap  52  through line A-A of  FIG. 5 ;  
       FIG. 7  shows a bottom view of the cap of  FIG. 5 ; and  
       FIG. 8  shows a top view of the base of  FIG. 4   a.   
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
      Illustrated in  FIGS. 1 and 2  there is shown a cross-section view of an evaporative air conditioner drain valve  10  which is constructed so as to be inserted into a floor  12  of a fluid containment reservoir of water in the form of a sump  38  ( FIG. 3 ) which is used in the evaporative air conditioning process as will be described further below with reference to schematic  FIG. 3 .  
       FIG. 1  shows the valve  10  in an open position while  FIG. 2  shows the valve  10  in a closed position.  
      The valve  10  has a generally circular valve body when viewed from a top view. The valve  10  includes a base portion in the form of base  4  and a cap portion in the form of cap  1 . When viewed in top view, the base  4  has a generally concave surface in the form of annular seat  14 . The valve  10  also has a valve outlet in the form of discharge outlet  16  to which a fluid release outlet such as dump pipe  48  ( FIG. 3 ) can be connected for conducting water away from the sump  38  to a storm water drain or other disposal system.  
      The base  4  includes valve inlets in the form of four inlet ports  18  which are equi-spaced around the perimeter of the base  4  above the annular seat, however only two are visible in cross section in  FIG. 1  and  FIG. 2 .  
      Between the base  4  and cap  1  is a flexible diaphragm in the form of diaphragm  2 . A pressure chamber  20  is defined between the diaphragm  2  and the cap  1 . Extending through the cap  1  to the pressure chamber is a cap conduit in the form of conduit  27  which is connectable to a source of water suppled to the evaporative cooler that is under pressure as will be explained below.  
      A fluid chamber in the form of chamber  22  is located between the base  4  and the diaphragm  2 . The flow of water through the valve  10  is shown by arrows  21 .  
      In use as will be explained further below with reference to  FIG. 3 , water under pressure causes the diaphragm  2  to flex in the direction of the base  4  as shown in  FIG. 2 . The generally concave inner surface of the annular seat  14  is shaped such that upon flexure of the diaphragm  2  under the influence of water under pressure in the pressure chamber  20 , the flexed diaphragm  2  makes contact with and seals against the concave inner surface of the annular seat  14  to thereby prevent flow of water through the inlet port  18  and the discharge outlet  16 .  
      A fluid release system in the form of a drainage systems  30  for an evaporative cooler  32  using the valve  10  described above will now be described with reference to  FIG. 3 . It will be appreciated that  FIG. 3  is a schematic diagram of the drainage system for the evaporative air cooler and therefore the diagram does not represent the actual dimensions of the evaporative air cooler or the construction of the valve  10 . The evaporative cooler  32  is a conventional evaporative cooler having an internal chamber which is covered by absorbent side walls  29 .  
      A gate valve  44  is also provided in the water inlet pipe  34  to supply mains pressure water to the evaporative cooler during cooling operation of the evaporative cooler  32  so that in use the absorbent walls  29  absorb water from the inlet pipe  34 .  
      The evaporative cooler  32  is also provided with a fan  35  located on the top of the evaporative cooler  32 . The evaporative cooler  32  sucks in dry air from the atmosphere and passes that dry air over the water saturated absorbent walls  29 . As is known in the art, the passage of dry air over the absorbent walls  29  that are saturated with liquid water causes the dry air to humidify and thereby cool. The evaporative cooler  32  is provided with a cool air outlet  36  to pass the cool air to a cool air distribution system (not shown) which distributes the cool air within the interior of a building.  
      The evaporative cooler  32  also includes a fluid containment reservoir in the form of sump  38  in which water, having passed over the absorbent walls  29 , collects in the bottom of the evaporative cooler  32 . A pump  40  is provided to circulate water located in sump  38  and return it via cooling water return line  42  to the top of the evaporative cooler  32  and redistribute the water over the absorbent walls  29 .  
      It is known in the art that control systems are provided to operate the evaporative cooler and hence, the control system to operate the evaporative cooler  32  is not described in detail here.  
      A bleed line  46  is connected to the water inlet conduit  34  downstream of the gate valve  44  and is connected to conduit  27  of the valve  10 . The bleed line  46  provides water under pressure from the mains water supply to the pressure chamber  20  of the valve  10 .  
      A dump pipe  48  is connected to the outlet  16  of the valve  10  and is used to drain water that has collected in the sump  38  during operation. The valve  10  is located in this embodiment, at the base of the sump  38  and at the opening of the dump pipe  48 . As will be described further below, the valve  10  closes when the evaporative cooler  32  is in operation to allow water to collect in the sump  38  and opens when the evaporative cooler  32  is not in operation to allow water to drain from the sump  38  via dump pipe  48 .  
      In operation, the gate valve  44  is turned on and a water supply is provided by the water inlet pipe  34 . Water is absorbed by the absorbent walls and excess water collects in the sump  38 . Water under pressure also passes into bleed line  48  which increases the pressure within the pressure chamber  20  and causes the diaphragm  2  to flex toward the concave shaped annular seat  14  of the valve  10  as shown in the closed position of  FIG. 2 . The flexure of the diaphragm  2  causes the inlet ports  18  and the outlet  16  in the valve  10  to be sealed and prevents drainage of water from sump  38 .  
      The dashed lines in  FIG. 2  show the diaphragm  2  over-flexing when a higher water pressure is applied in the chamber  20 . The dashed lines of the diaphragm over-flexure are shown to illustrate that precise control of water pressure supplied to the chamber  20  is advantageously not required because mains water pressure is sufficient to flex diaphragm  2  and close the valve  10 , which saves on the costs of installing and operating the drainage system  30 .  
      The gate valve  44  is turned off by the control system of the evaporative cooler  32  when the evaporative cooler  32  is shut down. The pressure in the bleed line  46  reduces which reduces the pressure within pressure chamber  20 , thereby causing the flexible diaphragm to flex back toward its open position as shown in  FIG. 1 . This allows the water within the sump  38  to be drained via dump pipe  48 .  
      It will be appreciated that the valve  10  advantageously allows water within sump  38  to be drained from the evaporative cooler  32  when the evaporative cooler  32  is no longer in operation. Advantageously, it is not necessary for the drainage valve  10  in the sump  38  of the evaporative cooler  32  to be manually opened to allow water in sump  38  to be released through dump pipe  48 . Furthermore, because the valve  10  is actuated by the mains water supply supplied to the evaporative cooler  32 , it is not necessary to provide a separately actuated valve in the dump pipe  48 . This is important, because it reduces the cost of providing a drainage system to the evaporative cooler.  
      Another advantage of the valve  10  is the combination of the diaphragm  2  and the concave shaped annular seat  14 , as the annular seat  14  is shaped so that it fits the natural flexure of the diaphragm  2  when the water under pressure is supplied to the pressure chamber  20 . This prevents the diaphragm  2  from over-stretching which increases the life of the diaphragm  2  in use. Furthermore, it will be appreciated that the only moving part in valve  10  is the diaphragm  2 , which advantageously reduces the cost of operation, manufacture and maintenance.  
      Furthermore, when the valve  10  is used in the evaporative air cooler  32  to drain water from the sump  38  after use, the operation of the valve  10  as described above ensures that there is an automatic discharge mechanism for discharging water from the sump  38 . The automatic discharge of water from the sump  38  when the evaporative air cooler is not in use ensures that Legionella bacteria does not thrive in water left in the sump  38  after use of the evaporative air cooler  32 .  
      The valve  10  ensures that all water is drained from the sump  10  when the evaporative air cooler  32  is switched off and the valve  10  is able to close properly in relatively harsh environments due to the resilience of the diaphragm  2 .  
      It will be appreciated that in other embodiments the sump  38  may not be located within the chamber of the evaporative cooler  32  but could be separate from the chamber of the evaporative cooler  32 .  
      Another preferred embodiment of a valve that can be used in a fluid release system will now be described with reference to FIGS.  4  to  8 . Referring to  FIG. 4   a  there is shown a cross sectional view through a base portion in the form of base  54  of valve  50  according to another preferred embodiment of the invention.  FIG. 4   b  shows a side view exploded view of a cap portion in the form of cap  52  and a flexible diaphragm  56  for valve  50 .  
      In assembly, the flexible diaphragm  56  is sandwiched between the base  54  and the cap  52 . The cap  52  is coupled to the base  54  by eight screws which are driven into screw holes  56  provided in the cap  52  and respectively into corresponding base screw holes  60 . One of the screws is shown in  FIG. 4  in the form of screw  58 .  
      In assembly, screw  58  is driven into screw hole  56  and pierces the flexible diaphragm  56  before being driven into the corresponding base screw holes  60 . The even distribution of the base screw holes  60  about the perimeter of the base  54  and the screw holes  56  about the perimeter of the cap  52 , ensures that the diaphragm  56  is firmly and evenly sandwiched between the, base  54  and the cap  52 .  
      The base  54  includes four equally spaced inlets in the form of inlet ports  62  which extend into the base  54  through to a fluid chamber in the form of chamber  64  which is defined between the diaphragm  56  and the base  54 . The base  54  includes a concave surface as shown by solid line  66 , which forms a annular seat  66  around four valve outlets in the form of outlets  68 . The outlets  68  connect to an outlet passage in the form of discharge outlet  70  as shown in  FIG. 4   a.    
      Referring now to  FIG. 4   b , in assembly between the diaphragm  56  and the cap  52  is defined a pressure chamber  72 , as the internal surface of the cap  52  provides a chamber when connected to the diaphragm  2  and the base  54  when the diaphragm  2  is in the unflexed position.  
       FIG. 5  which shows a top view of the cap  52  connected to the base  54  by the screws  58 .  FIG. 6  shows a cross-sectional view of the cap  52  through line A-A of  FIG. 5 , and  FIG. 7  shows a bottom view of the cap  52  of  FIG. 5 .  
      The centre of the cap  52  includes the bleed conduit  74  which connects to a bleed line such as the bleed line  46  shown in  FIG. 3 . As shown in  FIG. 6 , the conduit  74  extends throughout the cap  52  towards the pressure chamber  72 .  
      Referring now to  FIG. 8 , there is shown a top view of the base  54  with the screw holes  60  for receiving screws  58  in assembly. The inlet ports  62  are shown surrounding the generally concave annular seat  66  and the outlet ports  68  are shown on the concave shaped surface lying below the inlet ports  62 .  
      The valve  50  operates in the same manner as the valve  10  described above. In this regard, a fluid under pressure is supplied to fluid conduit  74  which increases the pressure in the pressure chamber  72  thereby causing the diaphragm  56  to flex towards the concave shape surface  67  of the base  54 . Flexure of the diaphragm  56  causes it to lie flush against annular seat  66 , thereby sealing both the inlet  62  and the outlet  68  so that the valve  50  is in a closed position to prevent fluids flowing from the inlet ports  62  to the outlet ports  68  and then out through the discharge outlet  70 .  
      When a fluid under a high pressure source connected to the conduit  74  is released, the fluid pressure in the chamber  72  reduces and the diaphragm  56  springs back to its unflexed state, thereby moving away from the concave annular sear  66  so that it is substantially horizontal when viewed in cross section. This allows fluid to flow from the inlet ports  62  to the outlet ports  68  and out towards discharge outlet  70 .  
      It will be appreciated that the valve  50  could be used in the drainage system  30  for the evaporative cooler  32  or in other applications which require fluid release systems requiring a valve to be actuated by a pressure source.  
      The base  54  and the cap  52  are made from glass reinforced plastic manufactured in a mould according to methods known to those skilled in the art. The diaphragm  56  is made from unreinforced rubber and the screws  58  are made from stainless steel. However, in other embodiments, the valve  50  could be made from alternative materials according to the fluid release applications in which it is employed.  
      It will also be appreciated that the present drainage system and valve can be applied to other applications where fluids are held in an apparatus under pressure. For example, the valve could be placed in a water tank and might be actuated automatically by the water pressure within the water tank. Additionally, instead of water, the fluid may be a gas and the sump a gas vessel.  
      It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.  
      The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention.