Patent Publication Number: US-7713330-B2

Title: Tower ionizer air cleaner

Description:
TECHNICAL FIELD 
     The present invention relates to an air cleaner, and more particularly, to a tower ionizer air cleaner. 
     BACKGROUND OF THE INVENTION 
     Air cleaners and purifiers are widely used for removing foreign substances from air. The foreign substances can include pollen, dander, smoke, pollutants, dust, etc. In addition, an air cleaner can be used to circulate room air. An air cleaner can be used in many settings, including at home, in offices, etc. 
     One type of air cleaner is an electrostatic precipitator. An electrostatic precipitator operates by creating an electrical field. Dirt and debris in the air becomes ionized when it is brought into the electrical field by an airflow. Charged positive and negative electrodes in the electrostatic precipitator air cleaner, such as positive and negative plates, attract the ionized dirt and debris. The electrodes can release the dirt and debris when not powered, allowing the accumulated dirt and debris to drop into a catch basin. In addition, the electrostatic precipitator can typically be removed and cleaned. Because the electrostatic precipitator comprises electrodes or plates through which airflow can easily and quickly pass, only a low amount of energy is required to generate the airflow. As a result, foreign objects in the air can be efficiently and effectively removed without the need for a mechanical filter element. 
     One type of electrostatic precipitator includes an electrostatic air moving mechanism that creates electrical field pulses in order to charge (i.e., ionize) the air. The device alternatingly charges and repulses the surrounding air in order to create air movement. However, although the resulting airflow is quiet, it is also very weak, and such air cleaner systems take a very long time to cycle through an average room air volume. In addition, an electrostatic air movement does not allow much control over the airflow volume, and is an on or off type of air movement system. 
     Another type of electrostatic precipitator is offered for sale by Brookstone, Inc., Nashua, N.H. The Brookstone air cleaner includes a single fan that draws air in at the base, ducts the airflow to the top of the tower, and draws the airflow down through an elongate electrostatic precipitator. The Brookstone electrostatic precipitator is tall and narrow, and the downward airflow travels the height of the electrostatic precipitator. The airflow is ultimately exhausted at a port in the base. 
     This prior art device has several drawbacks. The long, serpentine airflow path results in airflow energy loss due to its length and its corners. In addition, the long, looping airflow path can cause increased noise of operation. Moreover, the airflow is constrained to travel the full height of the electrostatic precipitator, reducing the contact of the electrostatic precipitator with the airflow and impairing the efficiency of the prior art device. 
     SUMMARY OF THE INVENTION 
     A tower ionizer air cleaner is provided according to an embodiment of the invention. The tower ionizer air cleaner comprises a tower chassis, with a base of the tower chassis including a small footprint, one or more airflow inlet openings in the tower chassis, and one or more airflow outlet openings in the tower chassis and substantially opposite to the one or more airflow inlet openings. The tower ionizer air cleaner further comprises an ionizer element positioned within the tower chassis and two or more fan units located within the tower ionizer air cleaner and affixed to the tower chassis. The two or more fan units are configured to provide an airflow between the one or more airflow inlet openings and the one or more airflow outlet openings and through the ionizer element. 
     A method of operating a tower ionizer air cleaner is provided according to an embodiment of the invention. The method comprises receiving user inputs through a control interface, operating an ionizer element and two or more fan units according to the user inputs, wherein the two or more fan units provide airflow through the ionizer element, storing current operational settings for the air cleaner, and recalling the current operational settings and resuming operation of the air cleaner at the current operational settings upon an electrical power interruption. 
     A tower ionizer air cleaner is provided according to an embodiment of the invention. The tower ionizer air cleaner comprises a tower chassis, with a base of the tower chassis including a small footprint, one or more airflow inlet openings in the tower chassis, and one or more airflow outlet openings in the tower chassis and substantially opposite to the one or more airflow inlet openings. The tower ionizer air cleaner further comprises an ionizer element positioned within the tower and a fan unit located within the tower ionizer air cleaner and affixed to the tower chassis. The fan unit is configured to provide a substantially horizontal airflow between the one or more airflow inlet openings and the one or more airflow outlet openings and through the ionizer element. 
     A method of operating a tower ionizer air cleaner is provided according to an embodiment of the invention. The method comprises receiving user inputs through a control interface, operating an ionizer element and a fan unit according to the user inputs, wherein the fan unit provides a substantially horizontal airflow through the ionizer element, storing current operational settings for the air cleaner, and recalling the current operational settings and resuming operation of the air cleaner at the current operational settings upon an electrical power interruption. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The same reference number represents the same element on all drawings. It should be noted that the drawings are not necessarily to scale. 
         FIG. 1  shows a tower ionizer air cleaner according to an embodiment of the invention. 
         FIG. 2  is a flowchart of a method of operating the tower ionizer air cleaner according to an embodiment of the invention. 
         FIG. 3  is a flowchart of a method of operating the tower ionizer air cleaner according to another embodiment of the invention. 
         FIG. 4  is a flowchart of a method of operating the tower ionizer air cleaner according to yet another embodiment of the invention. 
         FIG. 5  shows the tower ionizer air cleaner according to another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-5  and the following descriptions depict specific embodiments to teach those skilled in the art how to make and use the best mode of the invention. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these embodiments that fall within the scope of the invention. Those skilled in the art will also appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described below, but only by the claims and their equivalents. 
       FIG. 1  shows a tower ionizer air cleaner  100  according to an embodiment of the invention. The air cleaner  100  includes a tower chassis  101  with a base of the tower chassis  101  including a small footprint, one or more airflow inlet openings  104  in the tower chassis  101 , and one or more airflow outlet openings  110  in the tower chassis  101  and substantially opposite to the one or more airflow inlet openings  104 . The inlet and outlet openings  104  and  110  can comprise apertures, slots, grills, screens, etc. The inlet and outlet openings  104  and  110  operate to allow the airflow to flow through the tower chassis  101  and can allow the airflow to flow substantially horizontally through the tower chassis  101 . The inlet and outlet openings  104  and  110  in one embodiment are substantially vertically located, as shown. Alternatively, the inlet and outlet openings  104  and  110  can be staggered, offset, etc. The tower ionizer air cleaner  100  further includes an ionizer element  102 , one or more fan units  103 , and a controller  105 , all located within the tower chassis  101 . The ionizer element  102  can comprise an electrostatic precipitator or other air cleaning device that employs an electrical field. The ionizer element  102  in one embodiment includes a width W and a height H that is greater than the width W. Consequently, the ionizer element  102  can be elongate in shape, such as a rectangular or oval shape, for example. However, it should be understood that the ionizer element  102  can be of any shape, and the above shapes are given merely as examples and are not limiting. In addition, the ionizer element  102  can comprise planar electrodes. However, it should be understood that the electrodes can be of any desired shape. 
     In operation, when the tower ionizer air cleaner  100  is activated, the one or more fan units  103  generate an airflow through the tower chassis  101  and through the ionizer element  102 . The airflow can be substantially horizontal. The airflow therefore traverses the width W of the ionizer element  102 , and not the height H. In this manner, the effective area of the ionizer element  102  receives a maximum airflow volume for most efficient cleaning of the airflow. In addition, the straight airflow path through the tower ionizer air cleaner  100  reduces the amount of electrical power needed to achieve the airflow, reduces turbulence, and can reduce airflow noise. Moreover, the size of the tower chassis  101  can be reduced, as there is no need for a serpentine air channel running up and down through the tower ionizer air cleaner  100 . 
     It should be noted that the airflow can travel from right to left, as shown. Alternatively, the tower ionizer air cleaner  100  can be configured wherein the airflow travels from left to right, wherein the inlet  104  and the outlet  110  are reversed from those shown in the figure. 
     The controller  105  controls operations of the tower ionizer air cleaner  100 . The controller  105  can enable and disable a fan unit of the one or more fan units  103  and can enable and disable the ionizer element  102 . The controller  105  can include a processor or specialized circuitry that receives inputs, consults operational settings, and controls operations of the air cleaner  100 . In addition, the controller  105  can include a memory  106  that can be used to store operational settings and a control routine, among other things. For example, the memory  106  can store one or more fan speed settings, can store on/off states for the fan units  103  and the ionizer element  102 , can store user inputs received from the control interface  107 , etc. In one embodiment, the memory  106  comprises a non-volatile memory, wherein the contents of the memory remain even over a power cycle or electrical power interruption. 
     In one embodiment, the controller  105  is configured to store current operational settings and resume operation of the air cleaner  100  at the current operational settings upon an electrical power interruption. In another embodiment, the controller  105  is configured to receive the user inputs from the control interface  107 , operate the one or more fan units  103  and the ionizer element  102  according to the user inputs, and store current operational settings and resume operation of the air cleaner  100  at the current operational settings upon an electrical power interruption (see  FIG. 2 ). In yet another embodiment, the controller  105  is configured to store current operational settings, operate the one or more fan units  103  at a predetermined kickstart airflow level for a predetermined startup time period after the electrical power interruption, and operate the air cleaner  100  at the stored current operational settings after the predetermined startup time period (see  FIG. 3 ). In yet another embodiment, the controller  105  is configured to store current operational settings and is configured to operate the one or more fan units  103  at a predetermined kickstart airflow level if the one or more fan units  103  were operating at a low airflow setting before the electrical power interruption (see  FIG. 4 ). The controller  105  in this embodiment is further configured to operate the air cleaner  100  at the stored current operational settings after the predetermined startup time period. 
     The predetermined startup time period can be on the order of seconds, if desired. The predetermined kickstart airflow level can comprise any airflow level. In one embodiment, the predetermined kickstart airflow level comprises a medium airflow level, whereupon if the power interruption occurs when the air cleaner  100  is at a low airflow level setting, the air cleaner  100  will resume operation at a medium airflow kickstart level for the predetermined startup time period before reverting back to operating at the low airflow level setting. 
     The one or more fan units  103  include motors and impellers that provide the airflow. It should be understood that the one or more fan units  103  can comprise only one fan unit (see  FIG. 5 ), or can comprise multiple fan units  103 , such as the three fan units  103  shown in the current figure. Multiple, vertically spaced fan units  103  enable substantially horizontal airflow through the air cleaner  100 . The one or more fan units  103  eliminate the need for costly and space-consuming ducting and serve to increase the available area of the inlet and outlet openings. Therefore, by enlarging the available area of inlet and outlet openings, the air resistance is reduced. 
     The controller  105  is coupled to the one or more fan units  103  and to the ionizer element  102 , and can control the operation of the two components. For example, the controller  105  can turn the ionizer element  102  on and off and can turn the one or more fan units  103  on and off. In some embodiments, the controller  105  can control the speed of a fan unit  103 . 
     In an embodiment that includes multiple fan units  103 , the controller  105  can collectively or individually control the fan units  103 . For example, the controller  105  in one embodiment controls the collective speed of all fan units  103 , and can vary the fan speed over a continuous range, or can set fan speeds at specific values, such as low, medium, and high fan speeds, for example. Alternatively, in another embodiment the controller  105  can control airflow by activating specific individual fan units  103 . For a low airflow setting in this embodiment, the controller  105  can activate only a single fan unit. For a medium airflow setting, the controller  105  can activate two fan units  103 , etc. 
     The tower ionizer air cleaner  100  can additionally include a control interface  107  and a dirty indicator  108  that are also coupled to the controller  105 . In addition, the air cleaner  100  can include any manner of pre- or post-filter  109  that additionally mechanically filters the airflow. The pre- or post-filter  109  can be located in the airflow anywhere before or after the ionizer element  102 . 
     The control interface  107  comprises an input control panel for use by a user in order to control the tower ionizer air cleaner  100 . The control interface  107  can include any manner of input devices, including switches, buttons, keys, etc., that enable the user to control operation of the air cleaner  100 . In addition, the control interface  107  can optionally include output devices, such as indicators (including the dirty indicator  108  discussed below), output screens or displays, etc. 
     The dirty indicator  108  visually indicates a dirty condition to a user. The dirty indicator  108  can comprise any manner of visual indicator, such as a mechanical flag, paddle, signal, or symbol, for example. Alternatively, the dirty indicator  108  can comprise a light, such as an incandescent or fluorescent light element or a light emitting diode (LED), for example. The dirty indicator  108  is actuated when the ionizer element  102  is dirty, and therefore the dirty indicator  108  signals to a user that the air cleaner  100  needs to be cleaned. The dirty indicator  108  can be actuated upon any manner of dirty ionizer element determination. In one embodiment, the dirty indicator  108  is actuated after a predetermined elapsed time period, such as 720 hours of operation of the air cleaner  100 , for example. However, other time periods can be employed. 
       FIG. 2  is a flowchart  200  of a method of operating the tower ionizer air cleaner  100  according to an embodiment of the invention. In step  201 , user inputs for the air cleaner  100  are received. The user inputs can be received in a controller  105 , for example, and can be inputted through a control interface  107 . 
     In step  202 , the air cleaner  100  is operated according to the received user inputs. The user inputs can include fan speed settings, fan enable states, ionizer element enable states, etc. 
     In step  203 , the current operational settings of the air cleaner  100  are stored. The current operational settings can be stored in any manner of memory. The current operational settings can be continuously stored, such as in a circular queue, for example. Alternatively, the current operational settings can be periodically stored or stored upon any change in settings. 
     In step  204 , the air cleaner  100  determines whether there has been a power interruption in electrical power provided to the air cleaner  100 . The determination can be made in one embodiment by detecting a power-up state in the controller  105 . Alternatively, the controller  105  can detect a voltage level below a predetermined threshold. If a power interruption has occurred, the method proceeds to step  205 ; otherwise it loops back to step  201 . 
     In step  205 , the air cleaner  100  recalls the current (i.e., stored) operational settings and resumes operation of the air cleaner  100  and the current operational settings. In this manner, a power interruption does not interfere with the operation, and a temporary power drop or power interruption will not disable or modify the operation of the air cleaner  100 . 
       FIG. 3  is a flowchart  300  of a method of operating the tower ionizer air cleaner  100  according to another embodiment of the invention. In step  301 , user inputs for the air cleaner  100  are received, as was previously discussed. 
     In step  302 , the air cleaner  100  is operated according to the received user inputs, as was previously discussed. 
     In step  303 , the current operational settings of the air cleaner  100  are stored, as was previously discussed. 
     In step  304 , the air cleaner  100  determines whether there has been a power interruption, as was previously discussed. If a power interruption has occurred, the method proceeds to step  305 ; otherwise it loops back to step  301 . 
     In step  305 , the air cleaner  100  operates at a kickstart airflow level for a startup time period. The kickstart airflow level can comprise a default airflow level, such as a medium airflow level in one embodiment. The startup time period can comprise any desired time period. For example, the air cleaner  100  can operate at the kickstart airflow level for about 2 seconds. However, it should be understood that the startup time period and the kickstart airflow level can be set at any desired time length and airflow level. 
     In step  306 , the air cleaner  100  recalls the current (i.e., stored) operational settings and resumes operation of the air cleaner  100  and the current operational settings, as was previously discussed. 
       FIG. 4  is a flowchart  400  of a method of operating the tower ionizer air cleaner  100  according to yet another embodiment of the invention. In step  401 , user inputs for the air cleaner  100  are received, as was previously discussed. 
     In step  402 , the air cleaner  100  is operated according to the received user inputs, as was previously discussed. 
     In step  403 , the current operational settings of the air cleaner  100  are stored, as was previously discussed. 
     In step  404 , the air cleaner  100  determines whether there has been a power interruption, as was previously discussed. If a power interruption has occurred, the method proceeds to step  405 ; otherwise it loops back to step  401 . 
     In step  405 , the air cleaner  100  determines if the airflow level before the power interruption was a low airflow level. If it was a low airflow level, the method proceeds to step  406 ; otherwise the method jumps to step  407  and does not perform a kickstart airflow. 
     In step  406 , the air cleaner  100  operates at a kickstart airflow level for a startup time period, as was previously discussed. 
     In step  407 , the air cleaner  100  recalls the current (i.e., stored) operational settings and resumes operation of the air cleaner  100  and the current operational settings, as was previously discussed. 
       FIG. 5  shows the tower ionizer air cleaner  100  according to another embodiment of the invention. Components in common with  FIG. 1  share the same reference numbers. The air cleaner  100  in this embodiment includes a single fan unit  103 , comprising an elongate squirrel cage impeller  301  and motor  302 . The airflow is drawn through the inlet openings  104 , across the electrostatic precipitator  102 , and travels substantially horizontally through the squirrel cage impeller  301  and is expelled through the outlet openings  110 . The airflow leaving the squirrel cage impeller  301  travels substantially horizontally, as in the first embodiment. This configuration enables the use of only a single fan unit  103  in order to create the substantially horizontal airflow through the air cleaner  100 . 
     The tower ionizer air cleaner  100  according the invention can be implemented according to any of the embodiments in order to obtain several advantages, if desired. The invention can provide an effective and efficient ionizer air cleaner device. The effective area of the ionizer element  102  receives a maximum airflow volume for most efficient cleaning of the airflow. In addition, the straight, substantially horizontal airflow path through the tower ionizer air cleaner  100  reduces the amount of electrical power needed to achieve the airflow, reduces turbulence, and can reduce airflow noise. Moreover, the size of the tower chassis  101  can be reduced, as there is no need for a serpentine air channel up and down through the tower ionizer air cleaner  100 . As a result, the footprint of the air cleaner  100  can be reduced, allowing for placement of a highly efficient air cleaner in a small space. In addition, the available area of inlet and outlet openings is not limited and therefore the air resistance is reduced.