Abstract:
A recharging dehydrating breather for providing dehydrated air to electrical components includes a desiccant chamber configured to hold desiccant and a heating element configured to heat the desiccant held in the desiccant chamber to at least partially eliminate water. The device further includes a housing configured to hold the desiccant chamber and the heating element, an outlet configured to provide an outlet to guide the water away from the housing, and the outlet configured to be heated by the heating element. A process of configuring a recharging dehydrating breather for providing dehydrated air to electrical components is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit from U.S. Provisional Application No. 61/532,447 filed on Sep. 8, 2011, which is hereby incorporated by reference in its entirety for all purposes as if fully set forth herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a dehydrator for removing moisture from air. More particularly, the invention relates to a recharging dehydrating breather for high power electrical equipment and other devices. 
       BACKGROUND OF THE INVENTION 
       [0003]      FIGS. 1 ,  2 ,  3 , and  4  depict a known automatic recharging dehydrating breather  100 , i.e., the ARDB2 manufactured by Waukesha Electric Systems, Inc. (Waukesha, Wis.). The dehydrating breather  100  typically removes moisture from the air of load tap changer tanks, conservators, sealed tanks, control cabinets and the like. For convenience, the operation of the dehydrating breather  100  will be described with reference to a load tap changer tank which stores oil used to cool the tap changer. 
         [0004]    A headspace of the tank of the load tap changer (not shown) is connected to the dehydrating breather  100  by a pipe, tube, hose, etc. When the tank exhales, air flows from the headspace of the tank, through the hose, and into the dehydrating breather  100 , which vents the air to the atmosphere. When the tank inhales, air is drawn into the dehydrating breather  100  and passes through a desiccant, then through the hose to the tank. The desiccant dehumidifies the air provided to the tank, and, over time, typically becomes saturated with water. The dehydrating breather  100  removes the water absorbed by the desiccant using a process called recharging or regeneration. During a regeneration cycle, an electric heating element, disposed inside the dehydrating breather  100 , evaporates the water from a silica gel desiccant, and an embedded PC board ensures that regeneration occurs only during tank exhalation. 
         [0005]      FIG. 5  depicts a cross-sectional view of a dehydrating breather  100 , annotated to identify the various components, air flows and water flow. The dehydrating breather  100  typically includes a bottom molding with a condensate water filter vent (water drain), a tube and a top molding with the PC board and a top cap. 
         [0006]    The top molding includes slots through which air is normally drawn into and expelled from the dehydrating breather  100  through a slot. During regeneration, the heating elements evaporate the water absorbed by the silica gel desiccant, which condenses on the inner surface of the tube, drains to the bottom molding and passes through the filter vent. 
         [0007]    During cold weather operation, particularly when the ambient air temperature falls below 32° F., water in the filter vent can typically freeze, which prevents additional condensate from draining out and eventually renders the dehydrating breather  100  inoperable due to the build-up of water within the desiccant chamber. 
         [0008]    Accordingly, a low cost and/or low complexity solution to prevent the filter vent from freezing is needed. 
       SUMMARY OF THE INVENTION 
       [0009]    The foregoing needs are met, to a great extent, by the invention, wherein in one aspect a technique and apparatus are provided that provides a low cost and/or low complexity solution to the filter vent freezing. 
         [0010]    In accordance with one embodiment, a recharging dehydrating breather for providing dehydrated air to electrical components includes a desiccant chamber configured to hold desiccant, a heating element configured to heat the desiccant held in the desiccant chamber to at least partially eliminate water, a housing configured to hold the desiccant chamber and the heating element, an outlet configured to provide an outlet to guide the water away from the housing, and the outlet configured to be heated by the heating element. 
         [0011]    In accordance with another embodiment a recharging dehydrating breather for providing dehydrated air to electrical components includes chamber means for holding desiccant, heating means for heating the desiccant held in the chamber means to at least partially eliminate water, means for housing the chamber means and the heating means, outlet means to provide an outlet to guide the water away from the housing means, and the outlet means being heated by the heating means. 
         [0012]    In accordance with yet another embodiment, a process of configuring a recharging dehydrating breather for providing dehydrated air to electrical components includes holding a desiccant in a chamber, heating the desiccant held in the chamber with a heating element to at least partially eliminate water, housing the chamber and the heating element in a housing, arranging an outlet to guide the water away from the housing, and heating the outlet with the heating element. 
         [0013]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
         [0014]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
         [0015]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  shows a perspective view of a known recharging dehydrating breather. 
           [0017]      FIG. 2  shows a top view of the known recharging dehydrating breather of  FIG. 1 . 
           [0018]      FIG. 3  shows a front view of the known recharging dehydrating breather of  FIG. 1 . 
           [0019]      FIG. 4  shows a side view of the known recharging dehydrating breather of  FIG. 1 . 
           [0020]      FIG. 5  shows a sectional view (V-V) of the dehydrating breather depicted in  FIG. 2 . 
           [0021]      FIG. 6  shows a perspective of a recharging dehydrating breather according to an aspect of the invention. 
           [0022]      FIG. 7  shows a top view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 . 
           [0023]      FIG. 8  shows a front view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 . 
           [0024]      FIG. 9  shows a side view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 . 
           [0025]      FIG. 10  shows a partial sectional view (X-X) of the dehydrating breather depicted in  FIG. 9 . 
           [0026]      FIG. 11  shows a partial perspective sectional view (XI-XI) of the dehydrating breather depicted in  FIG. 9 . 
           [0027]      FIG. 12  shows a partial exploded view of the dehydrating breather depicted in  FIG. 6 . 
           [0028]      FIG. 13  shows a side view of a thermal conductor according to an aspect of the invention. 
           [0029]      FIG. 14  shows a top view of the thermal conductor according to the aspect of the invention shown in  FIG. 13 . 
           [0030]      FIG. 15  shows a sectional view (XV-XV of  FIG. 16 ) and a perspective view of a thermal conductor according to an aspect of the invention. 
           [0031]      FIG. 16  shows a sectional view (XVI-XVI) of the thermal conductor according to the aspect of the invention shown in  FIG. 15 . 
           [0032]      FIG. 17  shows a perspective view of a thermal conductor according the aspect of the invention shown in  FIG. 15 . 
           [0033]      FIG. 18  is a side view of a vent according to an aspect of the invention. 
           [0034]      FIG. 19  is a bottom view of the vent according to the aspect of the invention shown in  FIG. 18 . 
           [0035]      FIG. 20  is a bottom perspective view of the vent according to the aspect of the invention shown in  FIG. 18 . 
           [0036]      FIG. 21  shows a schematic diagram of a controller in conjunction with the recharging dehydrating breather according to an aspect the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. Embodiments of the invention advantageously provide a recharging dehydrating breather that operates in cold weather by reducing or eliminating frost and ice formation within the condensate water flow path of the dehydrating breather without substantially increasing the complexity, cost, power requirements, failure rate, etc., of the device. 
         [0038]    In one aspect, the recharging dehydrating breather may include a desiccant chamber, a heating element, and a water outlet that is heated by the heating element. 
         [0039]    In a further aspect, the recharging dehydrating breather may include a desiccant chamber, a thermal conductor, and a condensate vent. The desiccant chamber may include desiccant and a heater. The thermal conductor may be thermally coupled to the heater and may include a water inlet fluidly coupled to the desiccant chamber, a central bore, and a water outlet. The condensate vent  230  may include a central bore fluidly coupled to the thermal conductor water outlet and a screen may be disposed over the water outlet. In another aspect, the recharging dehydrating breather also may include a thermal coupler with a disc that abuts a bottom of the heater and a threaded shaft that may be threaded into a threaded upper portion of the thermal conductor central bore. 
         [0040]      FIG. 6  shows a perspective of a recharging dehydrating breather according to an aspect of the invention;  FIG. 7  shows a top view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 ;  FIG. 8  shows a front view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 ; and  FIG. 9  shows a side view of a recharging dehydrating breather according to the aspect of the invention of  FIG. 6 . In particular,  FIGS. 6 ,  7 ,  8 , and  9  show the details of a dehydrating breather  200 . The dehydrating breather  200  may include a body  240 , an upper housing  242  with an electric controller, and a removable cap  244 . The lower housing  202 , body  240 , and upper housing  242  may be each made from plastic, such as a polycarbonate or similar material, or, alternatively, metal or metal alloy, or the like. 
         [0041]    A component that requires dehydrated air, such as the headspace of the tank of the load tap changer, may be connected to the dehydrating breather  200  by a connector such as pipe, tube, hose, or the like. When the component exhales, air flows from the component, through the connector, and into the dehydrating breather  200 , which vents the air to the atmosphere. When the component inhales, air is drawn into the dehydrating breather  200  and passes through a desiccant, then through the connector to the component. The desiccant dehumidifies the air provided to the component, and, over time, may become saturated with water. The dehydrating breather  200  may remove the water absorbed by the desiccant using a process called recharging or regeneration. 
         [0042]      FIG. 10  shows a partial sectional view (X-X) of the dehydrating breather depicted in  FIG. 9 ;  FIG. 11  shows a partial perspective sectional view (XI-XI) of the dehydrating breather depicted in  FIG. 9 ; and  FIG. 12  shows a partial exploded view of the dehydrating breather depicted in  FIG. 6 . During a regeneration cycle, a heating element  252 , disposed inside the dehydrating breather  200  may evaporate the water from the desiccant by heating the same. Thereafter, the evaporated water may condensate within the dehydrating breather  200  and be directed to an outlet  290 . Portions of the water outlet are heated by the heating element  252  and accordingly freezing of the water and/or frosting is less likely to occur during cold weather. 
         [0043]    The dehydrating breather  200  may include the lower housing  202 . The outlet  290  may include one or more of a thermal coupler  210 , a thermal conductor  220 , and a condensate vent  230 . 
         [0044]    During a regeneration cycle, the heating element  252 , disposed inside the dehydrating breather  200  may evaporate the water from the desiccant by heating, and a controller may ensure that regeneration occurs only during component exhalation. 
         [0045]    The upper housing  242  may include a slot or vent port  256  through which air is normally drawn into and expelled from the dehydrating breather  200  and through a tank port  258 . A solenoid valve may couple the tank port  258  to either the desiccant chamber  246  or the vent port  256 . During normal operation, the solenoid valve may couple the tank port  258  to the desiccant chamber  246 , and the component inhales and exhales through the vent port  256  and desiccant chamber  246 . During regeneration, the solenoid valve may couple the tank port  258  to the vent port  256  to allow the component to exhale, and energizes the heating element  252  to evaporate the water absorbed by the desiccant, which condenses on the inner surface of the body  240 , drains to the lower housing  202  and passes through the outlet  290  such as the condensate vent  230 . If the component attempts to inhale during regeneration, the controller may suspend regeneration and the solenoid valve couples the tank port  258  to the desiccant chamber  246 . 
         [0046]    The desiccant chamber  246  may be located in the body  240 . In one aspect, the desiccant chamber  246  may include a cylindrical, perforated metal sleeve  250  that may be centrally located within the body  240  and may rest upon a screen/filter  248  located just above the lower housing  202 . The metal sleeve  250  and the screen/filter  248  may form the desiccant chamber  246 . 
         [0047]    The desiccant chamber  246  may include one or more of the heating element  252  and a heat distribution fin assembly  254 . Additionally, the desiccant chamber  246  may hold the desiccant that may be a silica gel desiccant. However, other types of desiccants are contemplated as well. The silica gel desiccant is not shown in order to simplify the figures herein. However, the silica gel desiccant will fill the voids between the heat distribution fin assembly  254  and the heating element  252  that exist in the space located in the metal sleeve  250 . 
         [0048]    In a particular aspect, the outlet  290  may include the thermal coupler  210  attached to, or abutting, the bottom of the heating element  252  and/or the heat distribution fin assembly  254  in order to conduct thermal energy or heat generated during the regeneration process to the thermal conductor  220  and, to a lesser extent, condensate vent  230 . The thermal coupler  210  may be attached to the thermal conductor  220  using a threaded or keyed connection, a press fit, or the like. However, other types of physical and mechanical connections are contemplated as well. The thermal coupler  210  and thermal conductor  220  may be made from materials with good to excellent thermal conductivity, such as, for example, brass, copper, aluminum, steel, and the like. In one aspect, the thermal coupler  210  is aluminum and the thermal conductor  220  is copper. The condensate vent  230  may be attached to the lower housing  202  using a threaded connection, and may be made from stainless steel, although other materials are contemplated. 
         [0049]    During regeneration, thermal energy or heat flows from the heating element  252  to the outlet  290 . This level of heat tends to prevent condensate water flowing through the outlet  290  from freezing, and, to a lesser extent, to prevent frost or ice from forming on the exterior surfaces of the outlet. 
         [0050]    In a particular aspect, thermal energy or heat flows from the heating element  252  to the thermal conductor  220 , via the thermal coupler  210 . This level of heat tends to prevent condensate water flowing through the thermal conductor  220  and out of the condensate vent  230  from freezing, and, to a lesser extent, to prevent frost or ice from forming on the exterior surfaces of the condensate vent  230 . 
         [0051]      FIG. 13  shows a side view of a thermal conductor according to an aspect of the invention; and  FIG. 14  shows a top view of the thermal conductor according to the aspect of the invention shown in  FIG. 13 . In particular,  FIGS. 13 and 14  present side and top views, respectively, of the thermal coupler  210  according to an aspect of the invention. The thermal coupler  210  may include a disk  302  and a threaded shaft  304 . The disk  302  may contact the heating element  252  or otherwise be in a thermally conductive relationship with the heating element  252 . Accordingly, the heat generated by the heating element  252  may be transferred to the thermal coupler  210 , and more specifically, may be transferred to the disk  302 . Thereafter, the heat may be transferred to the threaded shaft  304 . The threaded shaft  304  may be threaded and may extend downwardly from the disk  302 . The disk  302  may include one or more notches  306  to align with corresponding structure on a bottom of the heating element  252 . Other constructions of the thermal coupler  210 , threaded shaft  304 , and disk  302  are also contemplated by the invention and are within the spirit and scope of the same. 
         [0052]      FIG. 15  shows a sectional view (XV-XV of  FIG. 16 ) and perspective view of a thermal conductor according to an aspect of the invention;  FIG. 16  shows a sectional view (XVI-XVI) of the thermal conductor according to the aspect of the invention shown in  FIG. 15 ; and  FIG. 17  shows a perspective view of a thermal conductor according the aspect of the invention shown in  FIG. 15 . In particular,  FIGS. 15 ,  16  and  17  present side and sectional, sectional and perspective views, respectively, of the thermal conductor  220  according to an aspect of the invention. The thermal conductor  220  may have a cylindrical upper portion  402 , a cylindrical lower portion  404  and a central bore  408 ,  412  extending therethrough as shown by the dashed lines. The thermal conductor  220  is also contemplated to have other shaped configurations. 
         [0053]    A diameter of the cylindrical upper portion  402  may be greater than a diameter of the cylindrical lower portion  404  (as illustrated), or vice versa, or the diameters can be the same. In one aspect, the upper portion of the central bore  408  may be threaded to receive the threaded shaft  304  of the thermal coupler  210 , while the middle and lower portions of the central bore  412  may be smooth to facilitate condensate water flow. Other arrangements are contemplated as well. 
         [0054]    The thermal conductor  220  may include one or more openings  406 . The openings  406  may be circumferentially disposed in the cylindrical upper portion  402  of the thermal conductor  220  and may be fluidly coupled to the central bore  408 ,  412 . These openings  406  may serve as condensate water inlets and receive the condensate water as it drains from the lower housing  202 . Although six water inlets are depicted in  FIGS. 15 ,  16  and  17 , other quantities of water inlets are also contemplated, such as, for example, two, three, four, eight, etc. An opening  410  at a bottom of the thermal conductor  220  may serve as the condensate water exit. 
         [0055]    Accordingly, the thermal conductor  220  may be thermally coupled to the heating element  252  directly, through the threaded shaft  304  of the thermal coupler  210  or the like. The thermal coupling may ensure that the thermal conductor  220  is transferred heat from heating element  252  and maintains a temperature above freezing even when the ambient temperature is below freezing. Additionally, the central bore  408  may be fluidly coupled to the desiccant chamber  246  via the lower housing  202 . 
         [0056]      FIG. 18  is a side view of a vent according to an aspect of the invention;  FIG. 19  is a bottom view of the vent according to the aspect of the invention shown in  FIG. 18 ; and  FIG. 20  is a bottom perspective view of the vent according to the aspect of the invention shown in  FIG. 18 . In particular,  FIGS. 18 ,  19  and  20  present side, bottom and bottom perspective views, respectively, of a condensate vent  230  according to an aspect of the invention. The condensate vent  230  may include an end cap  502 . The end cap  502  may be configured with a hexagonal exterior shape to allow for construction, maintenance, and the like with common tools. However, other shapes are contemplated as well. 
         [0057]    The condensate vent  230  may include a cylindrical threaded shaft  504  in a central bore extending therethrough as shown by the dashed lines. A screen  506  may be disposed over a bottom opening of the condensate vent  230 . The screen  506  may prevent unwanted objects from entering the condensate vent  230 . A top opening  508  may be configured to receive the cylindrical lower portion  404  of the thermal conductor  220  including the opening  410  that forms a water exit. Accordingly, the central bore of the condensate vent  230  may be fluidly coupled to the opening  410  that forms a water exit of the thermal conductor  220 . In another aspect, the thermal conductor  220  may be attached directly to, or about, the heating element  252  and/or the heat distribution fin assembly  254 , and the thermal coupler  210  is not present. accordingly, the condensate vent  230  a receipt heat from the heating element  252  directly or indirectly 
         [0058]      FIG. 21  shows a schematic diagram of the controller in conjunction with the recharging dehydrating breather of the invention. In particular, the recharging dehydrating breather may include a controller  600 . The controller  600  may be located in the upper housing  242  or elsewhere in electronic communication with the dehydrating breather  200 . The controller  600  may be configured on a printed circuit board (PCB) or the like. The controller  600  may include a microcontroller  602  and supporting circuitry. The controller  600  may include a humidity sensor  606 , a vacuum sensor switch  610 , and a power supply  612 . 
         [0059]    The controller  600  may include LED indicators  618 . The LED indicators  618  may output various status indications of the controller  600  or the dehydrating breather  200  such as power, input/output port operation and the like. The humidity sensor  606  may sense the relative humidity of the air inhaled by the component  604  through the desiccant chamber  246 . The vacuum sensor switch  610  may sense whether the component is attempting to inhale while coupled to the vent port  256  during regeneration. Additionally, the controller  600  may actuate a solenoid valve  608 . The solenoid valve  608  in turn may operate a valve  614 . Other arrangements of the controller  600  are contemplated and are within the spirit and scope of the invention. 
         [0060]    The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention.