Abstract:
A module for generating ions in a flowing air stream includes a support structure having a central region adapted to pass a flowing air stream therethrough, and including a plurality of supports for positioning a filamentary ion-generating electrode in a polygonal configuration within the central region. The supports and filament are relatively moveable to wipe the surface of the filament at each support for removing accumulated contaminants on the filament.

Description:
RELATED APPLICATION 
   This application is a continuation-in-part of application Ser. No. 10/956,189, entitled “Air Ionization Module and Method,” filed on Sep. 30, 2004, which application is incorporated herein in the entirety by this reference thereto. 

   FIELD OF THE INVENTION 
   This invention relates to an ionizing system and more particularly to a self cleaning electrode system that includes a filamentary ion emitting electrode. 
   BACKGROUND OF THE INVENTION 
   Air ionizers that use gas, such an air, to disperse ions typically operate by moving the gas past ionizing electrodes that produce ions due to corona discharge in response to high ionizing voltage applied to the electrodes. 
   The moving gas disperses ions in a flowing stream toward objects to be charged or discharged. Particles, usually present in air, accumulate on a highly-charged surface of ionizing electrodes, thus reducing ion output and changing a balance between generated positive and negative ions produced by the ionizing electrodes. 
   Conventional methods and apparatuses for cleaning pointed or needle-like ionizing electrodes commonly include manually operated brushes that sweep tips of ionizing electrodes and dislodge accumulated particles. Alternatively, brushes installed on a rotating hub of a fan that produces the flow of gas relies upon centrifugal force to move the brushes in and out of contact with ionizing electrodes to dislodge accumulated particles. 
   In ionizers having an ionizing electrode formed as a thin wire (filament), the ionizing electrode also attracts particles and requires periodic cleaning. Such filament can also be cleaned manually as by brushing but over a substantially larger area than for ionizers with emitter points. And, areas next to supports for a filament cannot be sufficiently cleaned by a rotating brush. 
   SUMMARY OF THE INVENTION 
   In accordance with one embodiment of this invention, a filament stretched to a polygonal shape is cleaned by sliding the filament against supports that support the flexible filament in the polygonal shape. 
   An air ionizer includes an ionizing filament stretched between supports into a polygonal shape that is disposed within a flowing air stream. The filament slides against the supports to dislodge accumulated particles. In accordance to one embodiment of the present invention both ends of the filament electrode are attached to a lever that provides connection between the filament and a high voltage power supply. Sliding movement of the filament is produced by moving the lever or by moving the filament supports, or both. In another embodiment of the present invention high ionizing voltage can be supplied through at least one filament support and the lever can be fully situated within an area of a flowing air stream. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a frontal view of an ionizing blower from the impeller side of the fan module in accordance with one embodiment of the present invention. 
       FIG. 2A  and  FIG. 2B  are frontal views of an ionizing blower from the impeller side of the fan module showing a lever mechanism in accordance with another embodiment of the present invention. 
       FIG. 3  is a frontal partial view of an ionizing blower from the impeller side of the fan module showing a lever mechanism in accordance with yet another embodiment of the present invention. 
       FIG. 4  is a frontal view of an ionizing blower from the side opposite the impeller side of the fan module showing another lever mechanism in accordance with yet another embodiment of the present invention. 
       FIG. 5  is a detailed isometric view of a filament support and cleaning module in accordance with yet another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In one embodiment of the present invention, as illustrated in  FIG. 1 , rotary fan module  1  operates to move the air in an airflow direction. An ionizing electrode in a form of a filament (corona wire)  20  is stretched in a polygonal shape between wire supports  11  that are attached to cylindrical support structure  10  to position the filament in an area of maximum airflow and close to the outer edges of fan blades  2 . 
   Of course, the filament  20  can be situated on the inlet side of the fan module  1  where hub  3  is situated, for example, on the opposite or output side of the fan. Wire supports  11  may be shaped as hooks, eyelets, cylinders, or other suitable shape for supporting the filament  20  in stretched configuration, as shown, and facilitating the sliding of the filament  20  through the supports  11 . 
   Both ends of the filament  20  are attached to lever  30  at separate attachment points  31  and  32 , or optionally at the same point. Lever  30  extends outside of the support structure  10  and is situated between adjacent wire supports  13  and  14  within a cut-out area  12  of the support structure  10 . 
   High ionizing voltage is connected to corona wire  20  via a conductor  37  along lever  30 , as shown. Alternatively, high ionizing voltage may be supplied to the filament  20  through a wire support  11 , or via other convenient connection. 
   Lever  30  is mounted for movement along a cleaning path  40  that is substantially parallel to segment  21  of the polygon shape of filament  20 , with the attachment points  31  and  32  remaining located along segment  21 . The filament  20  thus slides along or through supports  11  to dislodge accumulated particles. Segment  21  may be longer than other segments of polygonal shape of filament  20  to facilitate cleaning of a full length of the filament  20 , including areas adjacent to the supports  11 , in response to movement of the lever  30  along the cleaning path  40 . 
   Lever  30  can be moved along the cleaning path manually, or by solenoid, pneumatic cylinder, or other suitable known device and the lever  30  can occupy any position within area  12  of the support structure  10  after a cleaning procedure, or can be moved back to an original position. 
   In another embodiment of present invention, as shown on  FIG. 2A , the support structure  10  of the fan module  1  is rotatable substantially coaxially with the rotary fan and hub  3  to facilitate cleaning of the filament  20  by rotating the support structure  10  along cleaning path  42  while retaining the filament  20  in fixed position. The axis of rotation of the support structure  10  is substantially coincident with the center of the polygon formed by filament  20 . 
     FIG. 2   b  shows a partial view of the same area of the fan module  1  as shown in  FIG. 2   a  and illustrates compensation for changes in length of the perimeter of the polygon formed by filament  20 . During a cleaning procedure the lever  33  and the attachment points  34  and  35  for the filament  20  that are carried by the lever  33  are shown moving along the arc in this illustrated embodiment, and such attachment points deviate from the line intercept  23  between supports  13  and  14 . Because the sum of the lengths of segments  21  and  22  of the filament  20  is greater than the length of the line intercept  23 , there is a need to compensate for the changes in required length of the filament  20  during movement of the lever  33  over the cleaning path  41 . This is achieved by attaching filament  20  to spring  36 , or other elastic element, or by otherwise accommodating changing distance between attachment points  34  and  35 . One such technique includes resilient supports  13 ,  14 , or other supports  11 , that can adjust at least radially to accommodate a fixed length of filament  20  so moved along the cleaning path  41 . 
   In another embodiment of the present invention, as shown on  FIG. 3 , the filament  20  is moved along a cleaning path via pivoted lever  50 .  FIG. 3  shows a partial view of the same region of the fan module  1  as  FIGS. 2   a  and  2   b . Lever  50  is disposed to rotate around pivoting point  55  along path  43  within the region  12  between supports  13  and  14 . Pivoting point  55  may be situated outside of the support structure  10 , or optionally within the perimeter of the support structure  10 . Elastic element such as spring  53  may be mounted on lever  50  to accommodate changes in the required length of filament  20  as lever  50  is moved along the cleaning path  43 . 
   In another embodiment of present invention the filament  20  is disposed on the output side of the fan module  1  where the support  5  for the fan motor is located.  FIG. 4  shows the support structure  10  installed coaxially with the rotational axis of the fan blades  2  on the output side of the fan module  1 . Lever  70  is mounted on the support  5  for pivotal movement around pivoting point  72  that may be positioned concentrically with the polygon formed by filament  20 . Lever  70  rotates along path  48  between supports  13  and  14 , and compensation for the required changes in filament length is achieved by altering the distance  77  between filament attachment points  75  and  76 . In one embodiment of the present invention, the attachment point  76  is located on lever  70  and attachment point  75  is located on an auxiliary lever  71  that pivots around pivoting point  73  located on lever  70 . Elastic element such as spring  74  between levers  70  and  71  maintains tension on filament  20  and compensates for change in required length of filament  20  during movement of lever  70  along the cleaning path  48 . Of course, a single U-shaped lever made of elastic material may serve the same purpose. High ionizing voltage is supplied to filament  20  through support  15 . Cleaning of the filament  20  is accomplished by rotating the support structure  10  while holding the filament  20  in fixed position, while sliding the supports  11 ,  13 ,  14 ,  15  over the filament, or by rotating lever  70  to slide the filament  20  through the supports  11 ,  13 ,  14 ,  15  in fixed position. 
   One or more of the supports  11  can protrude radially outside of the support structure  10  to facilitate both ease of rotating and, additionally, can intrude radially and be shaped as vanes for redirecting (collimating) the ionized air stream formed by the apparatus as described. Of course, the pivoting point  72  on lever  70  can also be placed outside the perimeter of support structure  10 . 
   Movement of support structure  10 , or of lever  70 , can be performed manually, or via an actuator such as solenoid  90  mounted on support  5  to apply force  49  to rotate the lever  70 . 
   Referring now to  FIG. 5 , there is shown a detailed view of the support structure and cleaning mechanism according to another embodiment of the present invention. The support structure comprises a body that includes a lower ring  16  and an upper ring  17 . Each ring includes lower and upper portions of the supports  161  and  171 , respectively. These supports form non-circular apertures  180  in which split bushings  18  can be placed and secured by protrusions  181 . Rings  16  and  17  can be molded of inexpensive plastic and the bushings  18  can be formed of material such as ceramic with high hardness and good resistivity to plasma and vibration. Bushings  18  are keyed by non-circular apertures  180  in a particular way with a radial split  182  oriented outwardly from the center of the support structure. Stretched filament  20  only contacts inner surfaces of the bushings  18 , and does not contact plastic rings  16  and  17 . The distance between supports  162  and  172  and  163  and  173  may be larger than between other supports. Lever  190  is pivotally mounted to rotate around shaft  191 , substantially concentrically within the support structure, along path  198 . Arms  192  and  193  of the lever  190  serve as flat resilient springs between supports  162 / 172  and  163 / 173 . The ends of filament  20  are attached at points  194  and  195  on respective arms  192  and  193  of the lever  190 . Spring resilience of the arms  192  and  193  keeps the filament  20  in tension and helps compensate for required length changes of the filament during a cleaning procedure in which the filament  20  is pulled through bushings  18  to remove adherent contaminants. The support structure may be rotated relative to the filament  20  retained in fixed position, or the lever  190  and filament  20  may be rotated relative to the bushings  18  held in fixed position. 
   High ionizing voltage is supplied to the filament  20  via pin  200  that protrudes outside the support structure for connection to a high ionizing voltage supply. Pin  200  may include a slot  201  for engaging the filament  20  and can protrude through hole  202  in support structure. Alternatively, high ionizing voltage may be supplied to filament  20  via at least one conductive bushing  18  that connects to a supply of high ionizing voltage. Also, high ionizing voltage can be supplied to filament  20  through contactless capacitive connection. 
   The shaft  191  is mounted on plate  196  that is supported via ribs  197  that may be formed as an integral portion of ring  16 . The lever  190  with a predetermined length of filament  20  attached thereto can be mounted on shaft  191  with the filament  20  placed into the partial holes  180  in the lower ring supports. The upper ring  17  is then attached to lower ring  16  with glue, snaps, or other known attachment schemes. Then, bushings  18  with radial splits  182  are slipped over the filament  20  and snapped into holes  180  to configure and tension the filament  20  in a polygonal shape. This forms the entire assembly for attachment outside of a fan module and for easy removal to reduce cost of construction, maintenance and repair.