Abstract:
Certain embodiments of the present invention provide a watering system configured to provide water to livestock. The system includes a water basin defining a trough configured to retain water, a reservoir mounted to the water basin, wherein the reservoir is configured to receive and retain water above the water basin. A water path is defined from the reservoir to the trough, wherein water within the reservoir is configured to pass into the water basin through gravity. A first heating element configured to heat water within the reservoir. A second heating element is configured to heat water within the trough, wherein the second heating element is separate and distinct from the first heating element.

Description:
RELATED APPLICATIONS 
     The present application is a division of U.S. application Ser. No. 12/695,344, entitled “System and Method for Heating a Poultry Watering Device,” filed Jan. 28, 2010, which relates to and claims priority from U.S. Provisional Application No. 61/153,378, entitled “Heated Poultry Waterer,” filed Feb. 18, 2009, both of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the present invention generally relate to a system and method for providing water to livestock, such as poultry, and more particularly, to a system and method for heating water within a watering device. 
     BACKGROUND OF THE INVENTION 
     Gravity-feed watering devices have been used for a number of years in order to provide water for livestock, such as chickens, to drink. In general, the watering device includes a basin having a low wall that defines a drinking trough. A metal or plastic water reservoir is mounted above the basin. Typically, the reservoir has a fluid capacity of one to five gallons. 
     In use, the reservoir is positioned on the basin such that an open end is downwardly-oriented, akin to a bucket that is turned upside down. In order to fill the watering device, the reservoir is detached from the basin. The reservoir is then inverted so that its open end is exposed. Water may then be filled into the reservoir, which then retains the water. After the reservoir is filled, the basin is reattached to the reservoir, and the device is tipped over, such that the basin is upwardly-oriented and the reservoir is downwardly-oriented. In this orientation, the outer circumferential wall of the basin overhangs the reservoir, as the diameter of the basin exceeds that of the reservoir. 
       FIG. 1  illustrates a cross-sectional view of a conventional watering device  10 . The device  10  includes a basin  12  having base  14  integrally formed with an outer wall  16  defining a water-retaining volume therebetween. The device  10  also includes a reservoir  18  having a base  20  integrally formed with circumferential walls  22 . An open end of the reservoir leads to a cavity  24  configured to receive and retain water  26 . 
     As shown in  FIG. 1 , the device  10  is in an operational configuration such that the reservoir  18  is attached to the basin  12 . A drinking trough  28  is defined between the outer wall  16  and the edges of the walls  22 . 
     A channel or notch may be formed proximate the edge of walls  22  of the reservoir  18 . The channel allows water to flow by force of gravity from the reservoir  18  into the trough  28 . As water flows out of the reservoir  18 , it is replaced by air that bubbles past the edge and collects in an air pocket above the water  26  contained within the reservoir  18 . 
     The water  26  inside the reservoir  18  flows into the drinking trough  28  until the water level in the trough  28  rises above the lower edge  30  of the reservoir  18 . Accordingly, air is prevented from entering the reservoir  18  to take the place of the water  26 . At this point, a vacuum forms above the surface of the water  26  within the reservoir, and ambient air pressure quickly balances the water and air pressure inside the reservoir  18 , thereby preventing additional water  26  from flowing into the trough  28 . 
     Watering devices, such as the device  10 , are often used outdoors or in unheated buildings, such as chicken coops. In these settings, air temperature may drop below freezing. In order to prevent ice from forming in the watering devices, some individuals opt to employ high wattage light bulbs above the watering devices. Alternatively, or additionally, heated metal bases may be used to heat the water. However, the use of light bulbs may prove very inefficient and ineffective, and heated bases typically cannot be used with plastic watering devices, as such could melt or otherwise damage the plastic. 
     United States Patent Application Publication No. 2008/0245308, entitled “Heated Poultry Fountain,” filed Apr. 9, 2007 (the “Clark application”), discloses a system that incorporates a heating element into the basin. The heating element covers the underside of the basin and is disposed along an inner wall of the drinking trough. The Clark application recognizes that water in the drinking trough will lose heat much faster than the water within the reservoir due to its smaller volume and direct exposure to ambient air. Accordingly, the Clark application devotes at least 40% of the heating element to heating the trough in order to have a higher wattage per volume of water in that volume. Thus, whenever the heating element is activated, water within the trough is heated to a higher temperature. 
     In a system such as disclosed in the Clark application, however, the thermostat that controls the power supplied to the heating element is positioned to monitor the temperature of the reservoir. Because the mass of water in the reservoir may be 30-50 times greater than the mass of water in the drinking trough, and the water in the reservoir is insulated to a certain degree, while the water in the trough is not, the rate of heat loss for water in the trough may be several orders of magnitude greater than for that in the reservoir. Hence, water in the trough cools much quicker than water within the reservoir. 
     For example, suppose the thermostat is set to activate when the water temperature reaches 4° C. Typical thermostats exhibit a hysteresis of around 10° C., so it is safe to assume that the water in the reservoir may have been initially 14° C. or higher. Assuming that the water in the drinking trough is heated to a much higher temperature because of the higher wattage per unit water volume around the trough, the water temperature in the trough may be as high as 40° C. 
     The rate of heat loss is given be the following equation:
 
 Q=mcΔ/Δt  
 
     where Q is the rate of heat loss, m is the mass of the water, c is the specific heat of water, ΔT is the change in temperature, and Δt is the length of time. 
     Assuming a best-case condition in which the rate of heat loss for water within the reservoir and the trough is the same, the equations for the reservoir and the trough may be set to equal one another:
 
Q 1 =Q 2  
 
 m   1   cΔT   1   /Δt=m   2   cΔT   2   /Δt  
 
     Using a one gallon reservoir as an example, the mass of the water in the reservoir may typically be around 10 times the mass of the water in the drinking trough. That is, m 1 =10m 2 . Thus,
 
10 m   2   cΔT   1   /Δt=m   2   cΔT   2   /Δt  
 
Δ T   2   /Δt= 10Δ T   1   /Δt  
 
     Therefore, in best-case conditions, when the rate of heat loss is the same for both the reservoir and the drinking trough, the rate of temperature change for the water in the drinking trough will be 10 times faster than for the water in the reservoir. Accordingly, the water in the reservoir may cool to 10° C., while the water in the trough is already freezing. 
     In actual conditions, however, the rate of heat loss for water in the drinking trough is typically much higher than that within the reservoir, so the discrepancy noted above is exacerbated. To compensate, the set point of the thermostat is typically much higher (for example, 16° C.). Then, while the water in the reservoir varies from 16° C. to 26° C., the water in the drinking trough varies from 0° C. to 40° C. Maintenance of water temperature at such an artificially high temperature is inefficient and costly. 
     Additionally, the higher temperature to which the water is heated increases the rate of evaporation. Therefore, the reservoir typically needs to be refilled frequently. Moreover, hotter water is less desirable for drinking, even by livestock. 
     If the thermostat is moved from the reservoir to the trough, the heating element may shut off too soon before enough heat is delivered to the reservoir. As a result, water within the reservoir may freeze and possibly cracker the reservoir. 
     SUMMARY OF THE INVENTION 
     Certain embodiments of the present invention provide a watering system configured to provide water to livestock. The system includes a water basin, a reservoir, and first and second heating elements. 
     The water basin defines a trough configured to retain water. The reservoir is mounted to the water basin. The reservoir is configured to receive and retain water above the water basin. A water path is defined from the reservoir to the trough. Water within the reservoir is configured to pass into the water basin through gravity. 
     The first heating element is configured to heat water within the reservoir. The second heating element is configured to heat water within the trough. The second heating element is separate and distinct from the first heating element. 
     The system may also include a first temperature sensor, such as a thermostat or thermistor, configured to sense the temperature of one or both of at least a portion of the reservoir and/or water within the reservoir. The first temperature sensor is configured to selectively activate and deactivate the first heating element based on the sensed temperature. 
     The system may also include a second temperature sensor, such as a thermostat or thermistor, configured to sense the temperature of one or both of at least a portion of the trough and/or water within the trough. The second temperature sensor is configured to selectively activate and deactivate the second heating element based on the sensed temperature. 
     The first heating element may be located underneath an open end of the reservoir. The second heating element may be located on a wall defining an inner boundary of the trough. 
     The system may also include a processing unit in communication with the first and second heating elements. The processing unit selectively activates and deactivates the first and second heating elements based on detected water temperatures. 
     Certain embodiments of the present invention provide a method of heating water within a gravity-feed poultry watering device. The method includes detecting the temperature of water within a water reservoir of the poultry watering device with a first temperature sensor, selectively activating and deactivating a first heating element proximate at least a portion of the water reservoir based on the detected temperature of the water within the water reservoir, detecting the temperature of water within a drinking trough connected to the water reservoir through a fluid path with a second temperature sensor, and selectively activating and deactivating a second heating element proximate at least a portion of the drinking trough based on the detected temperature of the water within the drinking trough. 
     The selectively activating and deactivating the first heating element may be based on a first temperature set-point. The selectively activating and deactivating the second heating element may be based on a second temperature set-point that differs from the first temperature set-point. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  illustrates a cross-sectional view of a conventional watering device. 
         FIG. 2  illustrates a cross-sectional view of a watering device, according to an embodiment of the present invention. 
         FIG. 3  illustrates a flow chart of a method of operating a watering device, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 2  illustrates a cross-sectional view of a watering system  32 , according to an embodiment of the present invention. The system  32  includes a basin  34  having a base  36  integrally formed with an upstanding circumferential wall  38 . A reservoir  40  is positioned over the basin  34 , and is configured to allow water to pass into an annular drinking trough  42  defined by the wall  38  and an interior island  44  of the basin  34 . 
     As shown in  FIG. 1 , the island  44  is lower than upper edges of the wall  38 . Accordingly, a fluid path  46  is defined from the interior of the reservoir  40 , over the island  44 , and into the drinking trough  42 . 
     At least one heating element  48  is secured above or below the upper surface of the island  44  and directed toward the interior chamber  50  of the reservoir  50 . The heating element  48  is configured to heat water within the interior chamber  50 . The heating element  48  may be a disk-shaped heating element that covers, or is underneath, a top surface of the island  44 . The heating element  48  is electrically connected to a temperature sensor  52 . 
     Additionally, at least one heating element  54  is secured on or underneath the island  44  proximate the trough  42 . The heating element  54  is configured to heat water within the trough  42 . The heating element  54  may be an annular-shaped heating element that tracks an inner wall of the basin that defines an inner boundary of the trough  42 . The heating element  54  is electrically connected to a temperature sensor  56 . 
     The sensor  56  is disposed proximate the inner wall of the island  44 . Optionally, the sensor  56  may be located proximate the bottom surface of the trough  42 . It has been found that placement of the sensor  56  in these locations provides exceptional sensing response. 
     The wattage of the heating element  54  may differ from that of the heating element  48 . Thus, the system  32  may enable differential heating of water at different locations. That is, water within the trough  42  may be heated to a first temperature, while water within the reservoir  40  may be heated to a second temperature that differs from the first temperature. 
     As shown, embodiments of the present invention provide a system  32  including two separate heating elements  48  and  54 . The heating element  48  provides heat to water within the interior chamber  50  of the reservoir  40 , while the heating element  54  provides heat to water within the trough  42 . Each heating element  48  and  54  is independently controlled by a separate and distinct temperature sensor  52  and  56 , respectively. 
     The heating element  48  may be electrically connected to the temperature sensor  52  through a switch  60 . Similarly, the heating element  54  may be electrically connected to the temperature sensor  56  through a switch  62 . The switches  60  and  62  allow the temperature sensors  52  and  56 , respectively, to selectively activate and deactivate the heating elements  48  and  54 , respectively, based on set-points of the sensors  52  and  56 . 
     Each heating element  48  and  54  is independently controlled by its respective thermostat  52  and  56  and the switches  60  and  62  to form a heating circuit. The two separate and distinct heating circuits can be wired in parallel to a single power source (not shown). 
     In certain embodiments, the sensors  52 ,  56 , and switches  60  and  62 , respectively, combine to form bimetal thermostats that are used as control devices for each heating element  48  and  54 , respectively. In such a configuration, each thermostat is in thermal contact with the outer surfaces of the island  44 . For plastic basins, a metal insert or screw that passes through the basin  34  may be employed to increase the thermal conductivity between the reservoir water and the thermostat, if desired. 
     The sensors  52  and  56  may be mechanical, such as bimetal thermostats, or electronic, such as thermistors. The switches  60  and  62  may be mechanical contacts, such as found in a thermostat, or a triac and/or a relay. 
     Additional heating elements with their own respective controlling devices may be added in parallel. For example, a small heating element may be desired to cover a tube leading from the reservoir to the drinking trough or to a detached drinking tough. 
     The temperature sensors  52  and  56  and heating elements  48  and  54  may be affixed directly to the underside of the basin  34  (such as an upwardly-indented portion that defines the island  44 ). Alternatively, the sensors  52  and  56  and the heating elements  48  and  54  may be detachably secured to mounting brackets that attach to the basin  34 . 
     The power supplied to the heating elements  48  and  54  may be alternating or direct current, and may be supplied through a single electrical cord leading to a power source, such that the heating circuits are wired in parallel. Optionally, power to each heating circuit may be routed from separate and distinct power sources. 
     Optionally, a processing unit  64  may be positioned on or within the basin  34 . The processing unit  64  may be in electrical communication with the heating elements  48  and  54  and the sensors  52  and  56 . The processing unit  64  may be programmed to control operation of the heating elements  48  and  54  based on detected water temperatures. That is, the processing unit  64  may activate and deactivate the heating elements  48  and  54  based on temperature readings that are relayed to the processing unit  64  through the sensors  52  and  56 . In this embodiment, the sensors  52  and  56  may be thermometers that detect the temperature of water and/or surface temperatures of the basin  34  at the locations of the sensors  52  and  56 . 
       FIG. 3  illustrates a flow chart of a method of operating a watering device, according to an embodiment of the present invention. At  70 , temperature within a water reservoir is monitored, as described above. At  72 , a temperature sensing circuit determines whether the water within the reservoir is above a temperature set-point. If the temperature exceeds the set point, the heating element is not activated at  74 , and the process returns to  70 . If, however, the temperature is below the set-point, the heating element is activated at  76  to heat the water within the reservoir, and the process returns to  70 . 
     Additionally, at  78 , the temperature of the water within the drinking trough is monitored with a separate and distinct sensing circuit, which determines at  80  whether the water within the trough is above a temperature set-point. At  82 , if the temperature of the water within the trough is above the set-point, the separate and distinct trough water heating element is not activated, and the process returns to  78 . If, however, the trough water temperature is below the set-point, at  84 , the separate and distinct trough water heating element is activated, and the process returns to  78 . 
     Embodiments of the present invention may be used in conjunction with the systems and methods shown and described in U.S. application Ser. No. 12/695,769, filed Jan. 28, 2010, entitled “System and Method for Automatically Deactivating a Poultry Watering Device,” assigned to Allied Precision Industries Inc., which is hereby incorporated by reference in its entirety. 
     Thus, embodiments of the present invention provide a system and method of efficiently heating water within a watering system. Because separate and distinct heating circuits are used to heat water within the trough and the reservoir, each heating circuit may be configured to heat water within each location to an ideal temperature that does not waste electricity. 
     While various spatial terms, such as upper, bottom, lower, mid, lateral, horizontal, vertical, and the like may be used to describe embodiments of the present invention, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like. 
     While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.