Patent Abstract:
An automatic condensate line purging device for HVAC condensation lines using pressurized gas. The purging device is installed in the condensate drain line of an air conditioning system allowing condensate flow through the device during normal operation where no clog has occurred in the condensate drain line. Should the drain line become clogged, a plug is displaced to seal the condensate drain causing the condensate to back-up up into the external condensate drain pan located beneath the condenser of conventional HVAC systems. When the drain pan fills with water, the safety float switch used to shut down the air conditioner is coupled to a solenoid valve mounted on the purging device wherein a charge of gas is directed into the drain line for removal of the clog.

Full Description:
PRIORITY CLAIM 
       [0001]    This application is based upon and claims the priority date of U.S. Provisional Patent Application No. 61/648,812, entitled “AUTOMATIC PURGING DEVICE FOR AC CONDENSATION DRAIN LINES”, filed May 18, 2012, the contents of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to the field of HVAC equipment and in particular to an automatic purging device for use with AC condensate drain lines. 
       BACKGROUND OF THE INVENTION 
       [0003]    Conventional air conditioner systems utilize a drain pan for collection and removal of condensation. Condensation is the water formed on the evaporator coil during the air conditioning process. A drain pan is situated below the evaporator coil to collect the condensate and direct the condensate fluid to a drain, via a condensate drain line. Unfortunately, over a period of time the drain line may become clogged due to algae, fungus, airborne debris entering the line, house settling, and so forth. If a drain line clogs, the drain pan will fill wherein a properly positioned safety float switch is used to shut off the air conditioning unit thereby stopping the process and further production of water. The occupant of the premise will understand that the air conditioner is not working resulting in a call to an AC specialist. The timing of a clogged drain line cannot be predicted, but happenstance typically calls for the failure to occur at the least convenient time for the occupant. The need for a proper drain line is most important during warm weather conditions which coincide with the highest air conditioner use. Unfortunately HVAC service people are typically the busiest at such time, reducing the possibility of a timely service call which can aggravate an already unpleasant experience. 
         [0004]    A clogged condensation line can be cleared by cutting open the line and pressurized water or air is flushed through the drain line to remove the clog. If the pressurized line is not properly installed leakage can occur right at the point of entry. A p-trap may have been installed allowing the repair from a particular area, however, in many instances the p-trap is the location of the clog. A low pressure flush may be inadequate and a high pressure flush may rupture the drain lines. Condensate drain lines are typically constructed of white PVC which is easy to assemble and acceptable to most code regulations. 
         [0005]    Drain lines can be unclogged using various techniques including vacuum, pressurized water, pressurized air, line replacement and so forth. Devices are also known to provide for an automated cleaning or purging of the blocked drain lines. 
         [0006]    U.S. Publication No. 2011/0061745 discloses an automated condensate drain line cleaning apparatus. The fluid flow regulation device may be electrically coupled with the controller to receive at least one control signal from the controller. The fluid flow regulation device may cause a fluid to flow into a condensate drain line through the fluid supply line responsive to at least one control signal. 
         [0007]    U.S. Pat. No. 7,930,898 discloses an air conditioning drain device comprising a tubular pipe assembly, a flapper assembly, and a service port assembly. The device automatically engages a flapper valve that prevents the reverse flow of condensate water, and provides a unidirectional pressure valve that can receive pressurized gas or liquid to dislodge a blockage. 
         [0008]    U.S. Pat. No. 7,857,004 discloses a vehicle based condensate drain line cleaning apparatus. The apparatus includes a controller, a fluid supply line, and at least one fluid flow regulation device. 
         [0009]    U.S. Pat. No. 5,530,988 discloses a device for unclogging pipes having a canister adapted to receive a pressurized gas, the canister adapted to the pipe or line that is to be unclogged. A method and device for providing an additive, such as a cleaning product, to a tank or line is also disclosed. 
         [0010]    U.S. Pat. No. 5,666,690 discloses a device for purging HVAC condensation lines. A body is adapted to contain a conventional gas cylinder such as a 12 gram CO 2  cylinder. The body is adapted to connect to a nozzle which in turn is connected to a connector that is attached to the condensation line. The body is rotated onto the nozzle in a manner that controllably releases gas pressure from the gas cylinder into the condensation line so as to cause a pressure buildup that purges the condensation line. 
         [0011]    U.S. Pat. No. 5,996,597 discloses a miniature gas cylinder for use in cleaning of a drain line. A control housing includes a cartridge housing portion for attaching a cartridge, containing a pressurized gaseous medium and preferably either a drain cleaning or algaecide fluid, thereto with an interior of the cartridge opening into the internal passage. 
         [0012]    U.S. Pat. No. 6,041,611 discloses a system for cleaning out a condensate drain line. The system comprises a manifold operatively placed in fluid communication with the condensate drain line. The manifold includes a first, second, and third line. In one embodiment, the first line extends from the manifold, and the second and third line are axially aligned with the condensate drain line. A water stream, which is operatively connected with the first line, is provided so that the water stream may be channeled through the manifold and into the condensate drain line. The manifold may further comprise a fourth line extending from the center of the manifold, with the fourth line having a fourth valve disposed therein. The system may employ a pan sensor for measuring the level of condensation within the secondary pan and activating an alarm once a predetermined level is reached. 
         [0013]    U.S. Pat. No. 6,427,458 discloses a device to clear a blockage from a drain line draining condensation from an air handler in an air conditioner. A pump with check valves attaches to one end of a drain line which drains condensation from an air handler. A handle on the pump is used to create respectively a vacuum or pressure within the pump which is communicated to the drain line. When sufficient vacuum or pressure is created, it will dislodge a blockage in the drain line allowing the drain line to naturally drain. A valve is placed at one end of the pump which allows accumulated liquid in a collection pan to be pumped from the collection pan in the process of clearing condensation from the air handler. 
         [0014]    U.S. Pat. No. 7,686,034 discloses an apparatus that applies chemicals to condensate water from an air conditioning condensate tray. It has an elongate body and a central cavity enclosed by an encircling wall. The central cavity receives chemicals to prevent the growth of microorganisms. A first tubular member is operatively connected at a first end to an aperture in the wall, and a second end extending outwardly for receiving condensate water from the condensate tray. A second tubular member is operatively connected to a second aperture in the wall opposite the first aperture aligned with the first member so that a cleaning brush may be passed through both members and into the condensate tray. Below the two tubular members a fluid outlet is provided with a connector for joining to a drainage system for draining the chemically treated condensate water from the cavity. 
         [0015]    U.S. Publication No. 2006/0042292 discloses a method of removing microbial and bacterial growth inside a blocked HVAC condensate drain line using compressed air without cutting into or disassembling the drain line. 
         [0016]    What is lacking in the art is an automatic drain line using replaceable gas cylinders that provides an automatic seal and directional purging of the condensate drain line. 
       SUMMARY OF THE INVENTION 
       [0017]    The present invention is an automatic in-line device for purging HVAC condensation lines by use of a gas discharge. The device consists of a housing that is placed in the PVC drain line. During normal operation where no clog has occurred the condensate will flow through the body to drain. Should the drain line become clogged, a float ball will be displaced to plug the drain line by use of the condensate as it fills the condensate drain pan. Once the drain pan is filled, a safety float switch is used to shut down the air conditioner and activate a solenoid valve mounted on the housing which is constructed and arranged to deliver a burst of pressurized gas into the drain line to remove the clog. It should be noted that upon discharge of the gas, the float ball will be tightly sealed so that the gas discharge is directed toward the clog in the drain line. Upon discharge of the gas and removal of the clog, water from the drain pan will now flow through the drain pipe further removing remnants of the clog. When the drain clears, the safety switch opens and the AC unit returns to normal operation. 
         [0018]    An objective of the invention is to provide an automatic and reliable device for purging condensation lines by use of a disposable gas canister. 
         [0019]    Yet still another objective of the invention is to provide a purging device which allows condensation lines to be purged without the attendance of professional HVAC personnel. 
         [0020]    Still another objective of the invention is to provide a device that employs conventional and disposable gas cylinders that can be easily replaced by the consumer. 
         [0021]    Still another objective of the invention is to provide a device for purging condensation lines which present minimal risk of further damage to the premises or to the drain lines. 
         [0022]    Yet still another objective of the invention is to provide a device that provides a method of cleaning smaller drain lines when needed to avoid line replacement. 
         [0023]    Still another objective of the invention is to provide a device that can clear drain lines have poor draining characteristics due to excessive bends, lack of proper fluid slope, or the like. 
         [0024]    Another objective of the invention is to provide a device that can automatically clear p-traps without opening of the drain line. 
         [0025]    Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification, include exemplary embodiments of the present invention, and illustrate various objects and features thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a side view of the instant invention; and 
           [0027]      FIG. 2  is a cross sectional side view of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    Now referring to the figures in general, set forth is the automatic in-line condensate drain purge device  10  of the instant invention. The device consists of a flow through housing  12  having a condensate inlet  14  and an outlet  16 . The condensate inlet  14  is fluidly connected to the outlet  16  by a chamber  18  which allows normal condensate draining from the condensate inlet  13  to the outlet  16 . The housing  12  is placed in-line with a new or preexisting condensate drain line. HVAC systems are heavily regulated and conventional code requires the air conditioner drain line to be white PVC pipe, the housing  12  is preferably made out PVC with the condensate inlet  14  and outlet  16  sized for an in-line direct coupling to the drain line allowing ease of installation. While glued PVC is preferable, the housing may also be threaded for compatibility. Further, the housing may have a threaded inlet and outlet wherein a PVC adapter may be employed to couple the threaded housing to a PVC pipe for glue weldment. 
         [0029]    The housing can be formed from a single piece or from multiple pieces that are fastened together. The condensate inlet  14  and outlet  16  can be of most any diameter, a ¾ inch diameter pipe is the most common size used for drain lines. Since the drain line is limited in slope, the condensate will drain slowly causing even the large lines to have drainage problems. In particular, it is commonly known that the drain lines flow so slowly that they are susceptible to clogging and for this reason an oversize drain line is thought to be the answer, however, any bend or slope issue can reduce the effectiveness of larger pipe. It is well known in the HVAC industry that most every drain line will clog as the flow rate is so slow and consists of water propone to bacterial growth. It is also known that poor installation techniques such as using smaller drain lines, multiple bends, or not accommodating a proper slope will cause some drain lines to clog sooner than others. 
         [0030]    The instant invention can work on any size pipe, wherein the condensate inlet  14  and outlet  16  can be sized accordingly to the drain line. The condensate inlet  14  includes removable cap  20  that is attached onto a receptacle  22  of the housing  12 , with the use of threads, engagement tabs  24 , or the like attachment mechanism. An O-ring, not shown can be used to seal the cap  20  to the housing  12 . The cap  20  is used to allow installation of a spherical float ball  30  or the like device capable of providing a plug in the condensate drain line to create a seal. The float ball  30  is used to seal the condensate inlet  14  should water back up through outlet  16 . The use of spherical shaped ball allows for ease of sealing on the inner surface  32  of the cap  20 . The float ball can be made of most any buoyant material such as plastic, ceramic, rubber or combinations thereof. The purpose of the floating plug, in the preferred embodiment a spherical shaped ball, is to provide an automatic sealing device to assure the pressurized gas to be released flows outward through the drain line to remove the clog. The result is a large rush of water, now pressurized, flows through the line in such a volume so as to create a turbulent flow scouring the lining of the pipe to provide a flushing of the pipe and associated clog removal. It should be noted that while the float is in the shape of a ball as a preferred embodiment, most any type of plug or the like float mechanism may operate, including different ways of sealing. For instance, the use of an O-ring may be employed to provide a seal between the cap  20  and housing  12  or provide an interference fit between the float ball  30 , wherein a rigid ball, such as a femoral plastic, may engage the seal by the O-ring seal. The deformity of the O-ring seal would be sufficient to provide a seal and mechanism. Still another example would be the use of a floating ball having a soft outer skin, such as a plastic ball over molded with rubber, or an all rubber ball having buoyancy. Another example would be the use of a flapper valve that can be formed within the cap  20 , not shown, which simply allows fluid to flow in a singular direction. 
         [0031]    The preferred embodiment employs the use of a floating ball  30 . The cap  20  can be removed and the ball cleaned and properly situated within a retainer seat  34 , wherein maintenance personnel can perform an inspection of the device and note that if the sealing surfaces are clean and available for drain discharge. The removal of the cap  20  will also provide an indication of the drain line condition as the fluid chamber  18  provides a bend so maintenance personnel will be able to detect slow drainage by any film that builds up along the fluid chamber  18 . 
         [0032]    A gas inlet  40  is in communication with the outlet  16  by use of a piercing tube  42  having any proximal end  44  and distal end  46 . In a preferred embodiment, the piercing tube  42  is separated from the flow chamber  18  by use of an enclosure wall  48 . The gas inlet  40  receptive to a gas cylinder  50  preferably having a threaded end  52  that engages reciprocal threads on the gas inlet  40 . In a preferred embodiment, a 3.2 oz (88 gram) CO2 cylinder is employed. The cylinder having sufficient capacity to discharge gas at a high rate with sufficient volume so as to remove a clog from most any drain line and provide a continuous pressurized gas flow to assure flushing of the clog through exhaustion of the cylinder gas. The CO 2  cylinder is readily available and low cost although most any type of gas may be employed. For instance, N 2  gas using a similar sized cylinder is known as well as well as straight compressed air. In addition, in many instances pressurized gases may be available wherein the cylinder may be replaced with attachment to a pneumatic gas source capable of providing a pressurized source. 
         [0033]    Various commercial sized cylinders are also known to exist from very small 12-16 gram disposable cylinders to larger cylinders that can be refilled. The preferred cylinder is 88 grams which is commonly available, low cost, and sufficient to allow a clean discharge of the drain lines. In addition, the 88 gram cylinder is lightweight wherein the housing and cylinder may be placed in-line without the need for additional support. A smaller cylinder could be used in installations where a small condensate drain line has been employed. For instance, a small air conditioner system found in a residential condominium might employ a inch line wherein as 12 gram cylinder is sufficient. Similarly, larger commercial installations having longer drain line runs may employ a larger cylinder or tee a couple of independent systems together, wherein the gas cylinder is remotely mounted for servicing multiple condensate drain lines. 
         [0034]    A solenoid  60  is coupled to the housing  12  and operatively associated with the cylinder  50 , so as to control discharge of the cylinder only upon initiation of a solenoid coil. The solenoid  60  includes a coil that is electrically coupled to a safety shut off switch commonly found in the emergency condensate drain pan, wherein a normally closed switch allows the power to an air conditioner controller along operation when the drain pan is empty to a normally open position, which is used to disconnect the air conditioner and at the same time provide power to the solenoid coil for operation to release gas from the cylinder  50  through the piercing tube  42  and to the drain line attached to outlet  16 . It is noted that for the safety switch to operate, the drain pain would need to be filled with water which means the condensate has backed up through the float chamber  18 , causing the float ball  30  to rise and seal fluid from backing through the condensate inlet  14 . Upon discharge of the gas, the chamber within the housing  12  will be pressurized, further forcing the ball  30  against the inner surface  32  of the cap  20 , with the remaining pressure causing a burst of water pressure flow to go down through the drain line until the gas cylinder is completely exhausted. Upon discharge of the gas cylinder  50 , the clog will be removed and with pressure released from the fluid chamber  18 , the ball  30  will reset into the seat  34  allowing the water from the drain pan to flow through the inlet  14  across flow chamber  18  and out the outlet  16  in a good volume so as to further cause any debris from the clog to be flushed to the drain. The purge device may include an indicator to notify when the gas canister is empty or filled. The indicator may be a pressure gauge having a visual display or indicator button. An indicator button is simply a spring loaded tab, not shown, that extends outward from the solenoid valve when sufficient gas pressure is detected within the valve. 
         [0035]    Upon exhaustion of the cylinder  50 , the unit can be serviced with the change of the cylinder and a maintenance check of the float ball  30 , to make sure no damage has occurred or build up of debris could otherwise impair further sealing. The solenoid  60  may include alarm mechanism to inform the consumer that the unit has been discharged and need of service. Such an indicator may be mechanical or electrical, either of which provides the intended notice of a spent gas cylinder  50  to be notified for purposes of maintenance. 
         [0036]    A discharge light, not shown, may be attached to the solenoid coil to indicate that the solenoid  60  has been operated which indicates that the gas cylinder  50  is in need of replacement. 
         [0037]    All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. 
         [0038]    It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any figures included herein. 
         [0039]    One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

Technology Classification (CPC): 8