Abstract:
A revised boiling chamber geometry in a vaporizer provides a scale collection area which prevents occlusion of the water inlet. A detachable scale collection cup allows for easy removal and cleaning of the cup.

Description:
FIELD OF THE INVENTION 
     The present invention relates to vaporizers, more specifically to a vaporizer having a boiling chamber shape which includes scale collection areas. In addition the present invention relates to a vaporizer having a detachable scale collection cup. 
     BACKGROUND INFORMATION 
     A vaporizer provides steam or moist air to a room by heating and thus evaporating water. This may be done to make a room more comfortable and to provide a healthier environment. 
     A typical vaporizer includes a reservoir for holding water and an evaporation chamber (also called a heating unit or boiling chamber) for accepting water from the reservoir. The evaporation chamber includes two electrodes, commonly manufactured from stainless steel, which may be, for example, flat plates, one inch wide and four inches long, which typically are separated by a distance of approximately one half inch. Each electrode may be connected directly to one lead of a conventional 120 volt household electric current supply. The electrodes are partially submerged by water supplied from the reservoir, and electric current flowing between the electrodes and through the water heats the water to the point of boiling. Steam and water vapor are formed and flow out of a hole in the boiling chamber to the surrounding air, humidifying the surrounding air. The boiling chamber concentrates heat provided by the electrodes in a space which is smaller than the entire boiling chamber, providing for faster boiling. 
     The water in the reservoir is usually supplied from a water tank or reservoir through a water supply hole in the bottom of the boiling chamber. The water supplied to the boiling chamber usually contains significant amounts of a variety of dissolved solids and minerals. These dissolved solids and minerals remain in the boiling chamber as the water evaporates, and gradually collect on the electrodes and in the chamber as a white, flaky powder generally called scale. As the scale formation becomes more pronounced over time, scales become detached from the electrodes and settle on the bottom of the reservoir. This scale may eventually occlude the water intake hole located in the bottom of the reservoir thereby restricting the flow of water into the chamber and consequently disrupting the ability of the vaporizer to generate steam. 
     In the past, manufacturers have provided instructions to vaporizer consumers to remove scale buildup by periodically washing the boiling chamber and electrodes. One recommended method is soaking the electrodes and boiling chamber in vinegar. This maintenance is a barrier to the use of such vaporizers. This maintenance also may pose a safety hazard. Typically, a lid or cover may be opened so that the user may access the boiling chamber. Opening this lid typically disables the delivery of current to the boiling chamber, which is a safety necessity, given that the electrodes receive 120V from the home electrical supply. However, such safety systems may work imperfectly or may be defeated. 
     Furthermore, some consumers simply do not wash the boiling chamber. In such a case the water intake hole becomes occluded and the vaporizer soon ceases to work, resulting in consumer dissatisfaction. 
     Therefore, there exists a need for a vaporizer which requires less maintenance than prior art vaporizers. Furthermore, there exists a need for a vaporizer which may be easily and safely maintained. 
     SUMMARY OF THE INVENTION 
     An exemplary embodiment of the present invention overcomes the above-described problems by providing a unique boiling chamber geometry which includes a scale collection area. The water intake hole is located away from the scale collection area, thus eliminating or greatly reducing the potential for occlusion of the water intake hole and consequently reducing the need to clean the boiling chamber. 
     In an alternate exemplary embodiment, a scale collection cup is provided which is easily detachable from the boiling chamber eliminating, or at least greatly reducing, the need to remove the boiling chamber for cleaning. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is illustrates a conventional vaporizer. 
     FIG. 1B illustrates a conventional boiling chamber and head unit. 
     FIG. 1C illustrates a cross-sectional view of a vaporizer unit having a conventional boiling chamber geometry. 
     FIG. 2 illustrates a cross-sectional view of one exemplary embodiment of the present invention in which a vaporizer has a boiling chamber with a scale collection area. 
     FIG. 3 illustrates a cross-sectional view of an alternate exemplary embodiment of the present invention of a scale collection area within a boiling chamber. 
     FIG. 4A illustrates a vaporizer having a scale collection cup which is detachable from the boiling chamber according to an exemplary embodiment of the present invention. 
     FIG. 4B illustrates a vaporizer having an exemplary alternate embodiment of a detachable scale collection cup. 
     FIG. 5 illustrates a vaporizer having an alternate embodiment of a detachable scale collection cup according to an exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An exemplary embodiment of the present invention provides a vaporizer in which the boiling chamber has a collection area in which scales can settle without interfering with the boiling chamber water inlet. In an alternate exemplary embodiment, the boiling chamber has a scale collection cup which can be quickly and easily removed and cleaned thereby preventing scale buildup from interfering with the operation of the vaporizer. 
     In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well known features often are omitted or simplified in order not to obscure the present invention. 
     FIG. 1A depicts a conventional vaporizer  1 . A conventional vaporizer  1  typically includes a reservoir  10  for holding water having an opening  12  on top for accepting a vaporizing unit  5 . The vaporizing unit  5  includes a head unit  20 , which may fit into the opening  12  of the vaporizer and a boiling chamber  100 . The head unit  5  may rest on an annular ledge  14  of the reservoir  10 , for supporting the boiling chamber  100 . 
     In FIG. 1B, the head unit  20  has been partially removed from the boiling chamber  100 . The head unit  20  may include a power cord  22 , which attaches to a conventional 120 volt home power supply via a standard two or three-pronged plug  24 . 
     For purposes of simplicity and clarity FIGS. 1C,  2 ,  3 ,  4 A,  4 B and  5  illustrate a boiling chamber  100  without showing the head unit  20 , power cord  22 , or plug  24 . 
     FIG. 1C is a cross-sectional view of the boiling chamber of FIG. 1B. A conventional vaporizer comprises a boiling chamber  100  which extends downward from the head unit  20  (FIG. 1A) for vaporizing the water supplied by the reservoir  10  (FIG.  1 A). The boiling chamber  100  provides a generally rectangular opening formed by a set of side walls  102  and a bottom wall  108 . The boiling chamber  100  may include an outer insulating wall (not shown) connected to the boiling chamber  100 . Thus, the general external shape of the boiling chamber  100  including the outer insulating wall, if present, may be conical or may have other desired configurations. When the boiling chamber  100  is inserted properly into the water filled reservoir  10 , the outer insulating wall and the set of side walls  102  define an air filled insulating area which is open at the bottom and closed at the top. 
     Two electrodes  120  extend downward inside the boiling chamber  100  from the head unit  20 . The electrodes  120  may be, for example flat stainless steel plates, one inch wide and four inches long, which are parallel and separated by a distance of approximately one half inch. The bottom wall  108  of the boiling chamber  100  includes a water intake opening  140  for allowing water to flow from the reservoir  10  into the boiling chamber  100 . 
     As water is evaporated from the boiling chamber  100 , minerals contained in the water stay behind in the boiling chamber  100 , and form scale on the electrodes  120  and on the inside of the boiling chamber  100 . After a period of time scale which becomes detached from the electrodes  120  will settle along the bottom wall  108  of the boiling chamber and occlude the water intake opening  140 . 
     FIG. 2 illustrates a cross-sectional view of an exemplary embodiment of the present invention. As shown in FIG. 2, bottom wall  108  is not flat but rather contains a raised central portion  109  which creates a scale collection area  111  due to the depression around the periphery of the raised central portion  109 . The raised central portion  109  is preferably in the shape of a curved dome. Preferably, the highest portion of the raised central portion  109  is close to or somewhat above the level corresponding to the lower end of the electrodes  120 . The water intake opening  140  is located, for example, near the highest point of the raised central portion  109 . The water intake opening  140  alternatively may be located along the side of the raised central portion  109 . Since the water intake opening  140  is located away from the scale collection area  111 , occlusion of the water intake opening  140  is prevented. 
     FIG. 3 illustrates a cross-sectional view of an alternate exemplary embodiment of the present invention. As shown in FIG. 3 the bottom wall  108  of the boiling chamber  100  contains a central depression  175 . The diameter of the central depression is preferably in the range of approximately one to two inches, so that the ends of the electrodes will be located above the central depression  175 . The depth of the central depression  175  is approximately one inch, preferably less. The water intake opening  140  is preferably located along the portion of the bottom wall  108  which does not form the central depression  175 . This arrangement of electrodes  120 , central depression  175 , and water intake opening  140  allows a significant amount of scale to collect in the central depression  175  while keeping the water intake opening  140  free of scale. Thus, scale may continue to detach from the electrodes  120 , and collect in the central depression  175  without interfering with the operation of the vaporizer. When scale fills the central depression  175 , the boiling chamber  100  should be removed and cleaned as described above. 
     FIG. 4A illustrates an alternate exemplary embodiment of the present invention. As shown in FIG. 4A, the vaporizer comprises a boiling chamber having a detachable scale collection cup  200 . The detachable scale collection cup  200  allows scale to collect in the bottom of the cup  200  and for the cup to be easily detached, cleaned, and reattached for continued use. Preferably, the collection cup  200  is attached and detached using a snap fitting or quarter turn threading. However, any suitable attachment and detachment means may be used. For example, other forms of threading, clamping or combinations thereof may be utilized. 
     The collection cup  200  preferably has a side wall  202  and a bottom wall  208 . A water intake opening  240  is located in the bottom wall  208 , but also could be located in side wall  202 . The diameter of the collection cup will preferably correspond to the diameter of the main portion of the boiling chamber  100 . The distal ends of the electrodes  120  preferably are located less than one inch and preferably approximately ¾ inch from the bottom of the collection cup near the level where the collection cup  200  attaches to the main portion of the boiling chamber  100 . The water intake opening  240  preferably is located near the center of the bottom wall  208  of the collection cup  200 . The bottom wall  208  of the collection cup  200  may be flat so that it forms a perpendicular angle with the side wall  202 . 
     As shown in FIG. 4B in an alternate exemplary embodiment, the bottom wall  208  of the detachable collection cup  200  may have a raised central area  209  which forms a scale collection area  211  around its periphery. The water intake opening  240  may be located, for example, near the highest point of the raised central portion  209 . The water intake opening  240  alternatively may be located along the side of the raised central portion  209  or in sidewall  202 . Since the water intake opening  240  is located away from the scale collection area  211 , occlusion of the water intake opening  240  is prevented. 
     FIG. 5 illustrates an alternate exemplary embodiment of a detachable scale collection cup  300 . As shown in FIG. 5, the scale collection cup  300  fits into a slot formed at the base of the boiling chamber  100 . To facilitate insertion and removal of the scale collection cup, a tab  317  is formed on the periphery of the cup  300 . The diameter of the scale collection cup  300  will approximate the diameter of the boiling chamber  100  to provide a water-tight seal between the cup  300  and the boiling chamber  100 . 
     Preferably, most of the non-electrical parts of the vaporizer, for example the non-electrical parts of the boiling chamber, including detachable scale collection cups are formed from plastic such as polypropylene or polyethylene which can withstand the heat of boiling water without deforming. 
     While the system and method of the present invention is described with respect to specific embodiments, it should be noted that the invention may be implemented in different manners and used with different applications. For example, although the typical structure and components of a conventional vaporizer have been described herein with reference to FIGS. 1A,  1 B, and  1 C, it should be noted that the present invention may be incorporated into any vaporizer, whether or not such vaporizer comprises each feature described in FIGS. 1A,  1 B, and  1 C.