Patent Grant
9630185
The present invention relates to the methods and the devices for cleaning of ion ionizing electrodes and it is applicable to home appliances and also in industry.
Technical solutions are known for cleaning electrodes from dust where the cleaning device travels during cleaning relative to a fixed ionizing electrode or a group of electrodes (e.g. see WO 2012/176099 and U.S. Pat. No. 8,106,367).
The cleaning device disclosed in WO/2012/176099 is formed either as a layer of porous fiber material or a layer of fine-dispersed balls arranged between two grids with cells whose size is bigger than the diameter of the ionizing electrode. At the same time the entire device is designed as a nonstandard solenoid where the permanent magnet and the cleaning device mount are shifted with respect to the fixed coil.
One disadvantage of such a device is the impossibility to use conventional solenoids which increases the complexity of the device.
Another disadvantage is the complicated procedure of selection of the thickness of the porous fiber material or of the diameter of the fine-dispersed balls and also the grids for different diameters of ionizing electrode.
U.S. Pat. No. 8,106,367 discloses an ionizer wherein a fixed array of planar electrodes is wiped between adjacent coils of a spring fixed to a manual slider which functions as a cleaning element. The spring axis is parallel to a line normal to the plane of the electrodes, which are cleaned as the spring is moved manually toward the electrodes while maintaining a constant distance between the spring axis and the line normal to the plane of the electrodes. Such a device cannot be used with a standard ionizing electrode whose tip diameter is much smaller than the diameter of the shank of the electrode.
U.S. Pat. No. 8,957,571 discloses an ionizing electrode with a cleaning mechanism wherein the cleaning mechanism is formed as a fixed tube with the ionizing electrode connected to the solenoid core travelling inside it.
A drawback of the device is the impossibility to use it for ionizing electrodes with needle-type ionizing edges or for ionizing electrodes made of materials such as tungsten or brittle materials such as silicon.
A problematic issue common to all the known devices is the removal of debris from the local cleaning spot.
An object of the present invention is to reduce or eliminate the drawbacks of the known devices and to provide a simpler device that is effective over the complete active length of the electrode.
This object is realized in accordance with the invention by a method and device for cleaning an ionizing electrode having the features of the respective independent claims.
The essence of the proposed invention is to use a spring most of whose coils having at least two degrees of freedom as a cleaning device adaptable to the changing flexion of the ionizing edge of a needle-shaped electrode placed between the spring coils.
When in the initial position the ionizing edge of the electrode protrudes from the upper spring board.
Cleaning of the ionizing edge of the electrode is performed during reciprocating motion of the electrode in a direction non-parallel to the longitudinal axis of the spring. As a result the ionizing edge of the electrode gets inside the spring or beyond its lower border and then returns to its initial position.
In needle-type electrodes, the diameter of the needle point is several times smaller than the diameter of the body of the electrode. Therefore in a proposed method and device according to the invention, for better adaptation of the spring, the default distance between the adjacent coils prior to penetration by the electrode tip is set smaller than the needle point diameter and the number of coils is determined from the equation below:
where:
Q—is the number of coils,
dmax—is the maximal electrode diameter,
l—is the distance between the adjacent coils.
To explain this formula conceptually, it will be appreciated that as the electrode penetrates adjacent coils of the spring, the coils are displaced and are pushed against the remaining coils of the spring which are thereby compressed. There must therefore be a sufficient number of coils in the spring such that their cumulative displacement equals or exceeds the diameter of the electrode.
In order to enable the use of the same spring for electrodes of different diameters, the distance between the adjacent coils can be controlled by adjusting the degree of spring compression.
In the proposed method and device the spring has an additional function to provide galvanic coupling between the electrodes and the high voltage terminal.
The ionizing electrode is formed as a thin-walled tube which enables part of the waste to be discharged through the cavity in the inner electrode during cleaning.
In some embodiments compressed air is forced into the inner cavity of the electrode during cleaning, thereby significantly improving the process of the electrode cleaning and also more effectively removing waste from the cleaning element.
A device according to the invention comprises the following parts: a body with a coil spring mounted inside it with ionizing electrode mounted between the coils of the spring, an actuator with power supply terminals and a plunger, with its edge being connected with the non-ionizing edge of the electrode, as well as electrically interconnected contact element and a high voltage supply terminal of the device.
In some embodiments the plunger has an air channel which is connected to the inner cavity of the electrode.
In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
In the following description of some embodiments, identical components that appear in more than one figure or that share similar functionality will be referenced by identical reference symbols.
The device operates as follows. In “PUSH” or “Ionizing” mode, the ionizing electrode 3 is pushed out through adjacent coils of the spring so as to project out of the body 1 of the device. High voltage fed to the terminal 8 is applied to the ionizing electrode 3 via the contact element 7 and the coil spring 2 both of which are electrically conductive. When this occurs, air in the vicinity of the tip of the ionizing electrode is ionized. During ionization of the air, adjacent coil springs are laterally displaced by the shank of the electrode and the resulting spring force ensures that good electrical contact is maintained between the spring and the electrode, whereby high voltage is continually applied to the electrode.
In “PULL” or “Cleaning” mode the actuator 5 retracts the plunger 4 and the electrode 3 attached thereto, thereby swiping the outer surface of the electrode 3 between adjacent coils of the spring 2 under the compressive force of these coils. During the retraction of the electrode, the adjacent coils of the spring thereby apply mechanical contact to the outer surface of the electrode 3 such that any debris or waste formed on its outer surface is removed by the spring 2. The spring 2 therefore serves a dual function in that it both applies high voltage to the ionizing electrode 3 and also wipes away surface debris that accumulates on its outer surface.
It should also be noted that during each reciprocating movement of the electrode, the tip of the electrode penetrates a complete cross-section of the coil spring 2 so as to intersect the adjacent coils at opposing extremities thereof each of which is thereby able to collect dust and other waste deposits from the electrode. This is distinct from above-mentioned U.S. Pat. No. 8,106,367 where, during manual swiping of the coil spring, the tip of the planar electrodes intersects adjacent coils of the spring on only one extremity thereof.
The ionizing electrode 3 may be formed of a solid material with a tip having a smaller diameter than its shank since also in this case the movement of the electrode will wipe surface debris off the electrode. However, there are advantages in forming the electrode 3 as a thin-walled tube. First, dust and other debris removed from the surface of the electrode may then be discharged through the hollow bore rather than accumulate on the surface of the spring coils. Secondly, the device is more easily adapted for use in both domestic and industrial applications, since the thin-walled tube can be used as an electrode support made either of such non-rigid materials as tungsten or such brittle materials as silicon. Tungsten has a very high melting point but is relatively soft and therefore not so easily capable of laterally displacing the spring coils. However, this disability is compensated for by its being supported inside a thin-walled rigid tube. Likewise, electrodes formed of brittle materials such as silicon can be supported inside a thin-walled rigid tube.
Preferably, the contact element 7 has an external thread for threadably engaging an internal screw thread in the housing. This allows the contact element 7 to be screwed into and out of the housing thereby adjusting the compression of the spring 2. Consequently, unlike known devices in which the entire cleaning element must be replaced whenever the diameter of the ionizing elements is changed, in the device according to the invention this is not required since the contact element 7 permits the distance between the spring coils to be easily adjusted by changing the degree of compression of the spring 2.
Reference is now made to
In both embodiments as described and illustrated in the figures, the electrode is disposed in a direction that is normal to the longitudinal axis of the spring thereby entering the spring at one extremity and exiting from an opposite extremity through the same coils. But this is not a requirement and the electrode may be oriented at any angle to the longitudinal axis of the spring that allows the tip of the electrode to engage between two adjacent coils and displace them apart in order to penetrate the coils. In such case, different pairs of adjacent coils will be displaced by the electrode on entry and exit, but both pairs of adjacent coils on entry and exit will nevertheless wipe against the electrode and remove dust and other accumulated debris.
It should also be noted that during cleaning mode, the distance between the spring axis and the electrode tip constantly changes as the electrode penetrates the cross-section of the coil, thereby intersecting the coils at opposite extremities. This, too, is distinct from above-mentioned U.S. Pat. No. 8,106,367 where as noted above separation between the normal axis of the electrodes and the spring axis remains constant.
The simplicity of the proposed device is achieved on account of the three elements mounted inside the body 1 each performing two functions as follows:
1. The spring 2:
2. The contact element 7:
3. Thin-wall tube shaped ionizing electrode 3 facilitates:
It should be noted that features that are described with reference to one or more embodiments are described by way of example rather than by way of limitation to those embodiments. Thus, unless stated otherwise or unless particular combinations are clearly inadmissible, optional features that are described with reference to only some embodiments are assumed to be likewise applicable to all other embodiments also.
| Number | Name | Date | Kind |
|---|---|---|---|
| 8106367 | Riskin | Jan 2012 | B2 |
| 8957571 | Riskin | Feb 2015 | B2 |
| 20150236484 | Chen | Aug 2015 | A1 |
| 20150336109 | Gefter | Nov 2015 | A1 |
| Number | Date | Country |
|---|---|---|
| 2012176099 | Dec 2012 | WO |
