Abstract:
A water distribution apparatus comprises a water user outlet facility and a water re-circulation loop. The water re-circulation loop comprises a water supply, a water pump for establishing and maintaining a flow of water in the loop, a water delivery path extending from the pump to a water user outlet facility, a water return path extending from the water user outlet facility to the water supply, and a thermal disinfection apparatus disposed in the water delivery path for improving the potability of the water within the loop.

Description:
BACKGROUND  
       [0001]    The invention relates generally to an apparatus and method for water distribution, and more particularly to an apparatus and method for water distribution for use in mobile applications. 
         [0002]    Most water distribution systems are once-through systems wherein water is dispensed from a water tank to a user outlet facility, including taps, faucets, bidets, toilets, coffee makers, dishwashers, etc., but only when user demand occurs. The path of water flow between water supply and the user outlet facility may include devices such as screens, filters, water purifiers, or the like, that are designed to improve the inorganic quality of water passing through them. Some water distribution systems may also include a means for recirculating stored water for the purpose of preventing stagnation by aeration of the water and to desensitize the water distribution system to environmental temperature extremes. Such systems include those described in U.S. Pat. No. 6,463,956 B2 entitled “Method of Water Distribution and Apparatus Therefor”, which issued Oct. 5, 2002, and U.S. Pat. No. 6,766,822 entitled “Method of Water Distribution and Apparatus Therefor”, which issued Jul. 27, 2004, the contents of both of which are hereby incorporated by reference in their entirety. 
         [0003]    Water distribution systems may be improved with the inclusion of design features and equipment that minimize the growth of biomaterial on the wetted surfaces of the system and in the water stored in the system, that modify the molecular structure of the inorganic contaminates to prevent their precipitation onto or the corrosion of the system surfaces, or that passively increase the operating reliability of water delivery to the water user outlet facilities when the system suffers component or power supply failures. 
         [0004]    In addition, while prior improvements to water distribution systems have attempted to improve the delivery methods and quality of potable water to the user outlet facilities, they usually do not provide active solutions to prevent water supply or water user outlet facility contamination that can be caused by the user&#39;s physical contact with the water user outlet facilities, such as drinking fountains, faucet nozzles, sprayer heads, water discharge screens, and the like. Stored water can also become foul due to algae growth in the water and biofilm growth on the internal wetted surfaces of the system after the water has experienced an extended dwell time in the system. As a result, contaminated water is delivered to the user. Also, there is the unresolved problem of contaminating the user through the user&#39;s normal physical contact with the water user outlet facilities or related fixtures, such as sinks, faucets, handles, towel and soap dispensers counter tops, and the like. 
         [0005]    For the foregoing reasons, there is a need for a new apparatus and method for potable water distribution system which improves the quality of stored water and water delivery to user outlet facilities. The new apparatus and method for water distribution should impede the deterioration of stored water, including a substantial reduction of organic and inorganic contamination in the system, and increase the delivery reliability of the available water supply to all water using facilities. The new apparatus and method for water distribution should also minimize inadvertent contamination of the water user outlet facilities by the user, as well as contamination of the user by contact with the external surfaces of the water user outlet facilities and related fixtures. 
       SUMMARY  
       [0006]    According to the present invention, a water distribution apparatus is provided, comprising a water user outlet facility including a water inlet port, a water outlet port, and a water outlet path extending from the water inlet port to the water outlet port; and a water re-circulation loop. The water re-circulation loop includes a water supply, a water pump in water flow communication with the water supply for establishing and maintaining a flow of water in the loop, a water delivery path extending from the pump to the water user outlet facility, a water return path extending from the water user outlet facility to the water supply, and a thermal disinfection apparatus disposed in the water delivery path for improving the potability of the water within the loop. 
         [0007]    In one aspect, the thermal disinfection apparatus comprises a heat exchanger having a heating portion including an air inlet port and an air outlet port, and a cooling portion including an air inlet port and an air outlet port, a source of ambient air, a first air delivery path from the source of ambient air to the inlet of an air compressor to pressurize and heat the ambient air, the air inlet port in the air compressor in fluid communication with the first air delivery path, an air return path from the heating portion of the heat exchanger, the air outlet port in the heating portion of the heat exchanger in fluid communication with the air return path, an expansion air turbine disposed in the air return path, a second air delivery path from the expansion air turbine to the cooling portion of the heat exchanger, the air inlet port in the cooling portion of the heat exchanger in fluid communication with the second air delivery path, and an air exit path from the cooling portion of the heat exchanger, the air outlet port in the cooling portion of the heat exchanger in fluid communication with the air exit path. 
         [0008]    In the second aspect, the thermal disinfection apparatus comprises a heat exchanger having a heating portion including an air inlet port and an air outlet port, and a cooling portion including an air inlet port and an air outlet port, a source of hot air, a first air delivery path from the source of hot air to the heating portion of the heat exchanger, the air inlet port in the heating portion of the heat exchanger in fluid communication with the first air delivery path, an air return path from the heating portion of the heat exchanger, the air outlet port in the heating portion of the heat exchanger in fluid communication with the air return path, an expansion air turbine disposed in the air return path, a second air delivery path from the expansion air turbine to the cooling portion of the heat exchanger, the air inlet port in the cooling portion of the heat exchanger in fluid communication with the second air delivery path, and an air exit path from the cooling portion of the heat exchanger, the air outlet port in the cooling portion of the heat exchanger in fluid communication with the air exit path. 
         [0009]    Also according to the present invention, a water distribution apparatus comprises a water user outlet facility, and a water re-circulation loop. The water re-circulation loop comprises a water supply, a water pump in water flow communication with the water supply for establishing and maintaining a flow of water in the loop, a water delivery path extending from the pump to the water user outlet facility, a first water return path extending from the water user outlet facility to the water supply, at least one water treatment device for improving the potability of the water within the loop, and a second water return path extending from the water delivery path between the water treatment device and the water supply. 
         [0010]    Further according to the present invention, a water distribution apparatus comprises a water user outlet facility including a water inlet port, a water outlet port, and a water outlet path extending from the water inlet port to the water outlet port, and a water re-circulation loop. The water re-circulation loop comprises a water supply, a water pump in water flow communication with the water supply for establishing and maintaining a flow of water in the loop, a water delivery path extending from the pump to the water user outlet facility, wherein the water inlet port is in water flow communication with the water delivery path, a water return path extending from the water user outlet facility to the water supply, and at least one water treatment device for improving the potability of the water within the loop. A tap valve is disposed in this water outlet path controllable by a water user to tap a portion of the flow from the water delivery path through this water outlet path while the water user outlet facility directs a remaining portion of the flow into the water return path. Also, this water path contains a pressurized water storage device in water flow communication with this water outlet path. 
         [0011]    Still further according to the present invention, a method is provided of supplying water to a water user outlet facility. The water supplying method comprises the steps of directing a tappable flow of water in a water re-circulation loop and heating the water in the loop to a predetermined temperature and for a predetermined period of time sufficient to degrade targeted biomaterials for improving the potability of the water within the loop. The water re-circulation loop includes a water pump for establishing and maintaining the flow of water in the loop, a water delivery path extending from the pump to the water user outlet facility, a water return path extending from the water user outlet facility to the pump, and at least one water treatment device for improving the potability of water within the loop. 
         [0012]    Another method of supplying water to a water user outlet facility according to the present invention comprises the steps of directing a tappable flow of water in a water re-circulation loop, including a water pump for establishing and maintaining the flow of water in the loop, a water delivery path extending from the pump to the water user outlet facility, a water return path extending from the water user outlet facility to the pump, and at least one water treatment device for improving the potability of water within the loop, and directing a portion of the flow of water in the water delivery path to the water return path. In one aspect, a magnet is provided in communication with the water flow for the prevention of mineral precipitation in the water flow path. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0013]    For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings: 
           [0014]      FIG. 1  is a schematic view of an embodiment of a water distribution system according to the present invention. 
           [0015]      FIG. 2  is a schematic view of another embodiment of a water distribution system according to the present invention. 
           [0016]      FIG. 3  is a close-up schematic view of an embodiment of a thermal disinfection apparatus for use with the water distribution system shown in  FIG. 2 . 
           [0017]      FIG. 4  is a close-up schematic view of another embodiment of a thermal disinfection apparatus for use with the water distribution system shown in  FIG. 2 . 
       
    
    
     DESCRIPTION  
       [0018]    Certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGS. Indeed, the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise. 
         [0019]    Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, an embodiment of a water distribution system according to the present invention is shown in  FIG. 1  and generally designated at  8 . Generally, the water distribution system  8  comprises a water storage tank  10  and a branch water return line  61  for recycling the majority of the water flow passing through an upstream disinfection unit  31  back to the storage tank  10 . The water distribution system  8  further comprises a pressurized water supply tank  70  to provide a supply of pressurized water to cause water to flow to water user outlet facilities  41 ,  42 ,  43  when a water distribution pump  20  is not working. 
         [0020]    The water storage tank  10  is initially filled with water through a water inlet line  11  from an external source (not shown). The quantity of water added to the system is controlled by the use of a valve  12 . The tank  10  also includes an air inlet vent  13  that serves to equalize pressure in the tank with that of the surrounding environment by allowing air from the surrounding environment to enter into and exhaust from the tank through a filter (not shown) that forms part of the inlet path. Stored water is drawn from the tank  10  through a discharge pipe  14  that leads through a T-connection  15  to a drain pipe  16 . The pipe  16  includes a valve  17  that is normally closed to prevent drainage, but which may be opened when it is desired to empty the tank  10  and the system. 
         [0021]    The T-connection  15  also connects to a delivery pipe  18 , which supplies the stored water to a pump  20 . In the FIGS., the pump  20  is schematically depicted as being connected by an electrical cable  80  to an electrical power source  81 . For mobile applications, the source  81  may be considered as representative of the on-board electrical system of an aircraft, train, bus, or recreational vehicle. 
         [0022]    The pump  20  discharges into a water distribution pipe  21  that leads firstly to a water filter  30  that serves to remove particulate matter, i.e. ions of chlorine and minerals and miscellaneous inorganic materials, then to a typical water disinfection unit  31  such as a lamp source that irradiates flowing water with ultraviolet radiation to kill or neuter organic contaminants. 
         [0023]    The water disinfection unit  31  discharges into a distribution pipe  74  that leads through a T-connection  60  to a return branch line  55 , which provides a return path of cleaned and purified water back to the water storage tank  10 . From the T-connection  60 , the water flows in a pipe  61  to a shut-off valve  62  and then on to a pipe  63  that attaches to a flow limiting device, such as an orifice  64 . The flow limiting device  64  controls the flow from the pump  20  at the maximum value prescribed by the performance limitations of the water disinfection unit  31 . From the flow control device  64 , the flow proceeds through a pipe  65  to a connection  66  inserted in a water return pipe  24  attached to the top of the water storage tank  10 . The return branch line  55  allows water to by-pass a portion of the water distribution system  8  and be returned back to the water storage tank  10  after the water has passed through water purification equipment. This feature provides a method of purifying the stored water supply for potable usage prior to delivering the water to the water user outlet facilities  41 ,  42 ,  43 . Moreover, the water distribution system  8  can continue to deliver all of the stored potable quality water to the water user outlet facilities  41 ,  42 ,  43  in the event that the disinfection unit  31  fails before delivery of the stored water. 
         [0024]    Returning to the T-connection  60  and the water flow supplying the water distribution path, the water available for delivery to the water user outlet facilities  41 ,  42 ,  43  flows through a pipe  75  to a T-connection supporting an accumulator  32 . The accumulator provides a limited volume of water supply when the system experiences a short term demand of high volume flow and thereby allows the system to maintain continuous pressurization. Water in the water distribution path then flows through the pipe  21  to the first of three water user outlet facilities  41 ,  42 ,  43  that are interconnected in succession by pipe segments  22 ,  23 . Each outlet facility  41 ,  42 ,  43  includes an associated tap valve  44 ,  45 ,  46  controllable by the water users, and an associated non-return valve (check valve)  47 ,  48 ,  49 . At the first non-return valve  47 , an additional pipe  67  is added to provide flow to a T-connection  68  that supports an adapter  69  that connects to a pressurized water tank  70  that provides a limited volume supply of reserve water for essential usage by a water user facility when the basic system is unable to do so. From the tank  70  and T-connection  68 , the water flow passes through a pipe  71  to an additional check valve  72  and on through a pipe  73  to a downstream water user outlet facility  76 . The check valve  72  is adapted to prevent water at the user outlet facility  76  from flowing in a reverse direction when the pressure in the water tank  70  is less than the pressure at the user outlet facility  76 . The pressure tank  70  may be incorporated for extra water storage capacity and thereby augment the capacity of the total water circulation loop. It is understood that this feature can also be applied to any of the water distribution lines extending from the other non-return valves  48 ,  49 . 
         [0025]    The water return pipe  24  leads from the last of the three representative water user outlet facilities  41 ,  42 ,  43  to a flow controlling device  50 , the T-connector  66  and then into the water storage tank  10 . 
         [0026]    Another embodiment of a water distribution system according to the present invention is shown in  FIG. 2 , which depicts a magnet  95  and a water purifier unit  97 . More particularly, the pump  20  discharges into a water distribution pipe  94  that leads firstly to a magnet  95 . The magnet  95  can be either a permanent type magnet or an electromagnetic type magnet. The inclusion of the magnet  95  in the water flow path prevents the precipitation of water borne minerals and thereby the attachment, adherence or growth of chemical or mineral deposits, commonly referred to as scale and corrosion, on the wetted surfaces of all of the water distribution system parts and equipment. 
         [0027]    A pipe  96  connects the magnet  95  to the purifier unit  97 . The purifier unit  97  may be a thermal type disinfection device, which employs the use of hot air to neutralize or degrade biomaterial being transported in the water passing through the purifier unit  97 . However, it is understood that there are numerous means for accomplishing the desired result of killing, neutralizing or degrading biomaterial in the water flow. A pipe  98  connects the purifier unit  97  with the T-connection and the water accumulator  32 , as described above. 
         [0028]    One embodiment of a purifier unit  97  for use according to the present invention is shown in  FIG. 3  in the form of a thermal disinfection apparatus, which uses a thermal transfer configuration wherein an ambient air supply heats the water flowing in the purifier unit  97 . Water flowing in the pipe  96  enters the heating heat exchanger  101  where its thermal energy level is increased to a specified minimum temperature and a corollary minimum dwelling time as necessary to provide sufficient thermal energy for neutralizing targeted biomaterials. The required thermal energy is imparted to the water by a flow of hot, pressurized airflow delivered by a turbo-compressor unit  100 . Ambient air enters a compressor inlet  104  and is compressed in a compressor  105 . The compressor  105  is driven by an energy source  106 . This energy source can be a variety of power suppliers, such as an electric motor, a hydraulic motor, a mechanical power converter, and the like. The compressed air having had work imparted to it is now in a higher thermal and pressure state. Preferably, the temperature will be greater than about 150° F., as a water temperature greater than about 150° F. is necessary to guarantee that most biomaterial will be killed, neutered or degraded. 
         [0029]    A pipe  108  connects the compressor  105  discharge port to the heat exchanger  101  air inlet port. The hot airflow from the compressor  105  passes through the heat exchanger  101  by way of air passages that maintain the airflow separate from the water flow. Conventional heat exchangers are suitable for such use, including tubular or plate and fin exchangers. As the hot pressurized air passes through the heat exchanger  101 , the heat exchanger  101  transfers thermal energy received from the compressor  105  to the water via the tube or fin wall in the exchanger. The pressurized air exits the heat exchanger  101  into a pipe  109  and then enters into the inlet of an expansion air turbine  107 . The warm pressurized air expands when passing through the turbine  107  and the potential (pressure) energy of the air is converted to kinetic (velocity) energy. The kinetic energy thus gained assists the powering of the system, thereby reducing the amount of energy provided by the source device  106 . The energy source device  106  extracts thermal (temperature) energy from the turbine  107  causing the air flow to lose potential and thermal energy in the expansion process and, as a result, the air experiences a reduction of pressure and temperature. The now cooled airflow passes from the turbine  107  through a pipe  110  and into a second, separate portion of the heat exchanger  102 . The air passing through this cooling exchanger  102  causes the heated water flow to be cooled to slightly higher than the temperature the water possessed when the water entered the heating portion of the exchanger  101 . The air having passed through the cooling portion of the heat exchanger  102  exits through a pipe  111 . The water flow exits the cooling portion of the heat exchanger  102  through the pipe  98  having had the bio-material killed, neutered or degraded. 
         [0030]    Another embodiment of a thermal disinfection apparatus for use as a purifier unit  97  according to the present invention is shown in  FIG. 4 . In this thermal transfer configuration, pressurized hot air derived from the compressor of a turbine type engine heats the water flowing in the purifier unit  97 . Water flowing in the pipe  96  enters a heating heat exchanger  101  where the thermal energy level of the water is raised. This is represented by an increase in temperature, preferably to at least about 150° F. for reasons explained above. This thermal energy is imparted to the water by a flow of hot pressurized engine (not shown) airflow delivered by a pipe  124 . This hot airflow passes through the heat exchanger  101  by way of air passages that maintain the airflow separate from the water flow. Such heat exchangers are in common use and are usually classified as tubular or plate and fin exchangers. The now, warm pressurized air exits the heat exchanger  101  into a pipe  125  and then into the inlet of an air turbine  126 . The air expands when passing through the turbine  126 . Thermal (temperature) and potential (pressure) energy is extracted from the air by means of a device  127 , which can be an electrical generator, a hydraulic pump, or mechanical power converter, each of which extract energy from the turbine  126  causing the air flow to lose pressure and temperature in the expansion process. As a result, the air experiences a reduction of pressure and a further reduction of temperature. The cooled airflow passes from the turbine  126  through a pipe  128  and into a second and separate cooling portion of the heat exchanger  102 . The air passing through the cooling portion of the heat exchanger  102  causes the heated water flow to be cooled to a slightly higher temperature than it had when entering the heating portion of the exchanger  101 . The air having passed through the cooling portion of the exchanger  102  exits this device through a pipe  129 . The water flow exits the cooling portion of the heat exchanger  102  through the pipe  98  having had the biomaterial killed, neutered or degraded. 
         [0031]    As described herein, a water distribution system according to the present invention is provided for producing a potable quality of water for delivery to the water user outlet facilities. In a further embodiment, biostatic or biocidal agents may be incorporated in substances applied to all surfaces of the water distribution system that can come in contact with water supplied to the water user. Biostatic or biocidal agents can also comprise substances used to fabricate or be applied as a coating to the materials used in the manufacturing of the surfaces in the water distribution system. These surfaces include, but are not limited to, the internal surfaces of the water tank, pump, pipes, faucets, and faucet exit screens or filters located in the water distribution system. Preferably, substantially all of the internal wetted surfaces of the water distribution system incorporate biostatic or biocidal materials, as well as the exposed surfaces of the water user outlet facilities. Biostatic and biocidal agents suitable for use in the present invention include noble metals, salts, halogen elements, radiation emitting or reflecting materials, and the like. 
         [0032]    Although the present invention has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that I do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, the water distribution may be used in a number of applications where potable water is to be delivered to a user. Accordingly, I intend to cover all such modifications, omission, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.