Abstract:
A domestic humidifier ( 10 ) is disclosed as including a water tank ( 34 ) for containing water, a basin ( 30 ) in a liquid communicable relationship with the tank ( 34 ), an adsorption medium ( 28 ) for breaking down water delivered to the adsorption medium ( 28 ) into water droplets floatable in air, a pump ( 22 ) for delivering water from the basin ( 30 ) to the adsorption medium ( 28 ), in which the tank ( 34 ) includes a water inlet ( 36 ) and a cover ( 38 ), and the cover ( 38 ) is movable to selectively close or open said water inlet ( 36 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a division of U.S. patent application Ser. No. 12/678,504, filed Mar. 17, 2010, which was a national stage of PCT International application number PCT/CN2007/070714, filed Sep. 18, 2007, the contents of which are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to a humidifier, in particular such a humidifier adapted to increase the indoor moisture content. 
       BACKGROUND OF THE INVENTION 
       [0003]    A domestic humidifier is a common home based electrical appliance which actively brings moisture into the indoor air and raises the water saturation content in the air. Most such humidifiers include mechanisms which break down the surface tension of water and carry the aerosolized water molecules into the air. All such mechanisms require a water tank and some kind of aerosolizing device. Some humidifiers make use of an ultra-sonic transducer to create fine water droplets and carry the water droplets by means of convection and directional air flow. A shortcoming of such a kind of apparatus is that water droplets of varying sizes are created, and noise is usually generated by the ultra-sonic transducer. Sometimes larger water droplets generated by the transducer will be blown out by a fan blower and be attached on an indoor surface before being evaporated into the air. Adhesion of water droplets on an indoor surface is clearly not desirable. 
         [0004]    In some other humidifiers, aerosolizing of water molecules is achieved by steam generated by the humidifiers. This means that a heating element is required and a water tank has to be coupled to with a water reservoir in the apparatus. Such an arrangement will at least slightly increase the indoor temperature and is more energy consuming in that electricity has to be supplied for operating the heating element. In addition, as heat is generated, more care has to be taken for safety reason. 
         [0005]    Moreover, all such existing humidifiers also require a water tank coupled to service a water reservoir. Almost all such conventional humidifiers make use of some kind of vacuum mechanism to fill the reservoir when water is consumed during operation, and thus water level is lowered. In order to operate in such a manner, the water tank should always be kept air tight. There is then the risk of water leakage out of the system as the water tank may have unnoticed cracks in which case air-tightness cannot be maintained. 
         [0006]    It is thus an object of the present invention to provide a humidifier in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the public. 
       SUMMARY OF THE INVENTION 
       [0007]    According to a first aspect of the present invention, there is provided a humidifier including a tank for containing water; a basin in a liquid communicable relationship with said tank; means for aerosolizing water; means for delivering water from said basin to said aerosolizing means; characterized in that said tank includes a water inlet and a cover, wherein said cover is movable to selectively open or close said water inlet. 
         [0008]    According to a second aspect of the present invention, there is provided a humidifier including a tank for containing water; a basin in a liquid communicable relationship with said tank; means for aerosolizing water; means for delivering water from said basin to said aerosolizing means; characterized in that said aerosolizing means includes an adsorption medium adapted to break down water delivered to said aerosolizing means into water droplets floatable in air. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
           [0010]      FIG. 1  is a sectional view of a humidifier according to a preferred embodiment of the present invention; 
           [0011]      FIG. 2  is a sectional view of the humidifier shown in  FIG. 1  in which the water tank is removed for refilling purpose; 
           [0012]      FIG. 3  is a sectional view of the humidifier shown in  FIG. 1  showing refilling of the water tank when coupled to the humidifier; and 
           [0013]      FIG. 4  is a schematic diagram of the manner of operation of the humidifier of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    A sectional view of a domestic humidifier according to a preferred embodiment of the present invention is shown in  FIG. 1 , and generally designated as  10 . The humidifier may be operated by municipal electricity or batteries. The humidifier  10  has a body  12  with an air inlet grill  14  (through which air may enter the humidifier  10 ) and an outlet grill  16  (through which air may exit the humidifier  10 ). A fan  18  is provided below the air outlet grill  16  and is operated by a motor  20 . The motor  20  also operates a pump  22  which is connected via a duct  24  to a cavity  26  above an adsorption medium  28 . The adsorption medium  28  is rough and is a metal mesh coated with various kinds of metal oxide; and porous materials, e.g. an aluminosilicate (such as sodium aluminosilicate (AlNa 12 SiO 5 )) doped with a transition metal. The air inlet grill  14 , the adsorption medium  28  and the air outlet grill  16  are arranged such that they are in an air communicable relationship. 
         [0015]    The body  12  of the humidifier  10  has a basin  30  with three upstanding plates  32   a,    32   b,    32   c,  the function of which will be discussed below. The basin  30  is also releasably engaged with a water tank  34  with a top water inlet  36 . Next to the water inlet  36  is a cover  38  hingedly engaged with the water tank  34 , and movable to selectively open or close the water inlet  36 . 
         [0016]    The lower end of the water tank  34  is releasably (e.g. threadedly) engaged with a valve assembly  40 . By way of such an arrangement, a lower water outlet  40  of the water tank  34  is closable by a spring-loaded valve  42  of the valve assembly  44 . The valve assembly  44  is operatively associated with a float  46  via a lever  48 , It can be seen that an upwardly extending finger  50  of the lever  48  acts on the valve  42  from below. 
         [0017]    As shown in  FIG. 2 , the water tank  34  may be detached from the rest of the humidifier  10 , e.g. for refilling of water. The spring-loaded valve  42  is arranged such that the valve  42  is spring-biased towards the lowered position in which the valve  42  closes the lower water outlet  40 . Water may then be added to the water tank  34 , e.g. from a water tap, while the water outlet  40  is closed, so as to contain the water. Alternatively, and as shown in  FIG. 3 , water may be introduced into the interior of the water tank  34  while the water tank  34  is still coupled to the humidifier  10 . It can therefore be seen that there will be no problem even if the cover  38  is opened during operation of the humidifier  10 . 
         [0018]    It can be seen that such an arrangement allows easy filling of water from the upper water inlet  36  of the water tank  34 , without having to ensure air-tight condition of the humidifier  10  and the attendant complicated structure and operating steps. 
         [0019]    As shown in  FIGS. 1 and 2 , the float  46  normally occupies a lower position on its own weight. In this position, and as can be seen in  FIG. 1 , the finger  50  of the lever  48  pushes the valve  42  upwardly, against the biasing force of the spring, to open the water outlet  40 , in which case the basin  30  and the water tank  34  is in a liquid communicable relationship. 
         [0020]    Turning now back to  FIG. 3 , when the water tank  34  is installed in the humidifier  10 , the finger  50  will open the valve  42  to allow water from the tank  34  to fall into the basin  30 . The float  46  will move vertically (either upwardly or downwardly) depending on the amount of water in the basin  30 . In particular, with the amount of water in the basin  30  increasing with time, the water in the basin  30  will gradually raise the float  46 , thus pivoting the lever  48  in a clockwise direction, to narrow the opening between the valve  42  and the water outlet  40 , until the outlet  40  is fully closed by the valve  42 , in which case the float  46  will occupy an upper position. If there is sufficient water in the water tank  34 , such an arrangement will ensure that water in the basin  30  is continuously replenished during use, until there is no water in the tank  34 . 
         [0021]    The pump  22  of the humidifier  10  draws water from the basin  30  and delivers the water, via the duct  24 , to the upper part  26 . The water then spreads downwardly across the adsorption medium  28 . The surface tension of the water is thereby broken down such that the water will form fine water droplets floatable in air. Some of the water droplets will be carried away by air drawn through the adsorption medium  28 , in a manner to be discussed below. The remaining water will drip downwardly through the adsorption medium  28  back to the basin  30 . 
         [0022]    The plates  32   a,    32   b,    32   c  are of different heights, with the plate  32   a  being the highest, and the plate  32   b  being higher than the plate  32   c.  These plates  32   a,    32   b,    32   c  collectively form a three-stage “cascade barrier” to screen out particles in the water from the adsorption medium  28 . Such particles may be from the ambient air or may be washed off from the adsorption medium  28  by the water dripping through the adsorption medium  28 . 
         [0023]    As shown in  FIG. 4 , during use, the motor  20  is activated to operate the fan  18  and the pump  22 . The pump  22  will draw the water from the basin  30  and deliver it to the upper part  26 , to pass through the adsorption medium  28 , to aerosolize the water into fine water droplets. Simultaneously, the fan  18  is operated to create a negative air pressure within the interior of the humidifier  10 , whereby air is drawn into the humidifier  10  through the air inlet grill  14 , then through the adsorption medium  28 , and subsequently out of the humidifier  10  through the air outlet grill  16 . 
         [0024]    The air passing through the adsorption medium  28  will pick up the fine water droplets in the adsorption medium  28 , thus increasing the moisture content of the air discharged to the environment through the air outlet grill  16 . 
         [0025]    The flow rate of the air drawn across the adsorption medium  28  depends on the speed of rotation of the fan  18 , and is adjusted to optimize the water to air mass transfer rate. One or more sensors may also be installed at or adjacent the air outlet grill  16  to measure the humidity level of the discharged air. Signals from the sensor(s) are then fed back to adjust the fan speed so as to achieve a desired humidity level. 
         [0026]    It should be understood that the above only illustrates an example whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention. It should also be understood that various features of the invention which are, for brevity, described here in the context of a single embodiment, may be provided separately or in any appropriate sub-combinations.