IL150766A - Method of ion generation and ion generator - Google Patents

Abstract

A method of ion generation and dispersion using a fan, high AC voltage source and a system for ion emission comprising not less than one ion emitter and a diode for supplying positive and negative voltage to the at least one ion emitter wherein the system for ion emission is rotated in space relatively to a fixed part of the fan. פירוט זה נבחן בהתאם לתקנה 35 לתקנות הפטנטים, תשכ" ח-1968 This specification was examined in accordance with regulation 35 of the Patent Regulations, 5728-1968.

Description

METHOD OF IONS GENERATION AND ION GENERATOR 150766/3 METHOD OF IONS GENERATION AND ION GENERATOR Field of the Invention Method of ion generation and ion generator relate to the methods and generators, which use one high voltage AC source for ions generation, air ionizing electrodes (emitters) and a fan which generates air flow, and they can be used for bipolar and unipolar ionization of air and for static charges elimination.

Background of the invention All the known ion generators include one or more high voltage AC or DC sources and ion emitters, as well as fans or air compressors that produce airflow for ion removal from the generator to the environment.

Ion emitters are usually formed as needles or thin wires, which are mounted either opposite a grounded screen or opposite to each other in front of or behind the fan, depending on the construction.

Among the important parameters of ionizers are uniform ion concentration in airflow and balance of positive and negative ions in bipolar ionization.

In a well-known device two ak-ionizing emitters mounted opposite each other in front of the fan supply alternating voltage from two outputs of one AC power supply, which is completely insulated from the ground (see US Pat. 5.055.963).

Here balance of positive and negative ions is achieved through isolation of power supply and of all the device parts, including fan, which are adjacent to the emitters, from the ground.

Methods of bipolar ion generation are known in which high AC voltage from the high voltage terminal of mis power supply via capacitor is supplied to 150766/3 ion emitters mounted behind the fan and the low voltage terminal of the mentioned power supply is grounded.

Each emitter is mounted facing a grounded element and alternatively ionizes the air with positive and negative ions at a frequency of the AC power supply. (See US Pat. 4.092543 and US Pat. 4.216.518).

In these inventions positive and negative ions balance is achieved by means of bias voltage generated across a capacitor in case of imbalance in the emitted ions, which causes equalization of emission currents.

One of the limitations of these ionization methods and ion generators is low frequency used in the AC voltage power supply. This is due to the fact that the ions under the action of electric field generated between the emitter and the screen have to have an opportunity to move away from the emitter over a distance such that their return to the emitter is impossible at the next polarity change on it.

The use of low frequency in AC power supplies does not allow having a small size power supply and the generator as a whole.

One of the limitations of the mentioned ion generation methods and generators is that the use of a single high voltage AC power supply is suitable only for bipolar ionization.

Further, in the known ion generation techniques and ion generators both positive and negative ions or either one of the selected polarity ions can be generated. (See US Pat. 3,936,698, US 4,333,123, US 4,542, 434, US 4,689,715, US 4,809,127, US 4,901,194).

The limitation of these inventions is in the use of no less than two high voltage power supplies, which provide for universality of these generators owing to the possibility of simultaneous or separate activation of these power supplies. 150766/4 One of common limitations of all the known ion generation techniques and ion generators is small ionization area of one emitter in comparison with the fan airflow area, which necessitates using of numerous emitters for uniform ions distribution in the airflow, as follows from US 4,757,422 and US 4,092,543, or JP 9245935.

There are also known patents wherein ion emitters are mounted on a rotary part of the fan or the ionizer as follows GB 2120864, GB 2141589, FR 2576157, US 3. 873. 835, US 4.363. 072. These inventions designated only for unipolar ionization, which in fact is one of its main disadvantages.

A type of ventilation systems is available which comprises axial fans with big fan blades (up to 1.5), such as ceiling fans, or tangential fans with rotor length up to 1.5m such as in room conditioners. In such systems this limitation is extremely critical.

Another common limitation of the known methods of ion generation and ion generators is ion emission level drop during ion generator use because of dust settlement from the airflow on the ionizing electrode. The emission level drop rate depends mainly on the amount of dust in the airflow.

The purpose of the present invention is eliminating of the existing limitations.

For achieving this object, in the proposed method of ion generation which uses a fan, high voltage AC power supply with grounded low potential terminal and ion emission system having no less than one ion emitter and one diode used for applying any polarity voltage to the emitter, rotation of ion emmiter and the above mentioned diode mounted on the mobile part of the fan is accomplished relatively to the fixed part of it. Energy from high potential terminal of high voltage AC power is supplied to the above mentioned ion emission system via capacitive coupling. 150766/3 Capacitive coupling is an air capacitor consisting of two parts - stator and rotor, whilst the stator and the rotor are fastened to the fixed and mobile fan parts respectively.

The use of capacitive coupling using air capacitor eliminates frictional losses, which appear in energy transmission through contact.

Owing to the use of high frequency AC power supply (50÷100kHz) in the invention air capacitor capacitance can be small (10÷100pF), which in turn does not necessitate big size condenser.

Rotation in space of the system used for ions emission mounted on the mobile part of the fan yields uniform ion concentration in the airflow with only one emitter owing to airflow turbulence at the fan output and owing to ion generation at the instants the rotating emitter is at different points of the frontal plane of the fan. Note that by the term "space" is meant the space where the system is located in.

Further, it is well known that airflow between the fan blades during their rotation is specified by strong nun-uniformity of velocities of separate airflow components.

So, the airflow velocity at the rear surface of the fan blades is very low, and it is maximal adjacent to the front plane of the blades.

Since the entire airflow containing all the dust present in this space passes the fan blades, the part of the airflow passing the low-speed airflow area in unit time will be smaller than that passing the high-speed airflow area.

In the proposed invention this feature is used to decrease the emitter covering with dust during the use.

For this purpose the emitter is mounted in the area of low-speed airflow and consequently lower dust amount.

In one variant of the invention for unipolar ionization energy from high voltage AC power supply is applied to the system for ion emission via capacitive coupling and grounded axis of the mobile fan part or grounded shaft 150766/3 of the fan motor. This variant realizes a standard way of obtaining unipolar voltage from AC voltage power supply with doubled output voltage.

In tangential fans with long rotors thin wires arranged on the rotor surface lengthwise can be used as ion emitters, however in this case the problem is of reaching balance of positive and negative ions in bipolar ionization.

This problem stems from the fact that in tangential fans emitters mounted on the rotor pass through points with different ionization conditions between the rotor and the body during the rotor rotation; this includes areas with high and low airflow velocity, areas with different distances between the rotor and the fan body and areas having grounded elements.

Therefore at arbitrary switching on the high voltage AC power supply different polarity emitters may reach areas with different ionization conditions, which will result in imbalance between positive and negative ions in airflow.

In order to attain balance between positive and negative ions when using a tangential fan, the present invention provides synchronization between the instances of every polarity ion emitters passage a certain point on the fixed part of the fan and the instant of high voltage AC power supply activation. In this way ion emitters of both polarities are subjected to identical ionization conditions, thus providing for a balance.

Another object of the invention is unipolar air ionization with any polarity ions with a single high voltage AC power supply, without excluding the possibility of bipolar ionization.

For achieving this object there is provided synchronization of the instant the selected polarity ion emitter passes a preset point on a fixed fan part with the instant of switching on the high voltage AC power supply.

Indeed, if the high voltage power supply is switched on whenever the selected polarity ion emitter passes a certain point in the area most advantageous for ionization, such as high airflow velocity area, when the 150766/3 second emitter is in the area with the worst ionization conditions, a 100% imbalance can be achieved. Namely, the outgoing airflow will be free from the opposite polarity ions.

Ion generator based on the suggested method consists of the following parts: fan, high voltage AC power supply, system for ions emission, which is formed with no less than one ion emitter and one diode with additional air capacitor incorporated in it, which comprises rotor and stator parts, in which the ion emission system as well as the rotor part of the air capacitor are mounted on the rotating part of the fan, and the stator part of the mentioned capacitor is mounted on the fixed part of the fan.

A diagram of the generator designated for bipolar ionization is shown in Fig l.

The generator has different polarity ion emitters 1 and la, diodes 2 and 2a, rotating part of the fan 3, rotor part 4 of air capacitor and its stator part 5, high voltage AC power supply 6, insulator 7, fan motor 8 and motor shaft 9, as well as tenninals 10 for power supply to motor 8 and power supply 6.

The stator part 5 of air condenser is mounted on insulator 7 which is in turn fastened to motor 8 which is the stationary (fixed) part of the fan, while rotor part 4 of the air capacitor together with diodes 2 and 2a and emitters 1 and la are mounted on rotating part 3 of the fan which is connected to shaft 9 of motor 8.

At the same time emitters 1 and la are connected to different polarity terminals of diodes 2 and 2a, while the other different polarity terminals of these diodes are connected to the rotor part 4 of air capacitor and its stator part 5 is connected to high potential terminal of high voltage AC power supply 6, and the low voltage terminal of power supply 6, supply terminals of power supply 6 as well as motor 8 supply terminals are connected to terminals 10. 150766/3 Ion generator operates as follows: AC voltage from the high voltage terminal of the high voltage AC voltage power supply 6 is transferred from stator part 5 to rotor part 4 of the air capacitor. Then positive voltage pulses are via diode 2 supplied to positive ion emitter 1, and negative voltage pulses are via diode 2a supplied to negative ion emitter la.

Corona discharge is formed and both positive and negative ions are generated between ion emitters 1 and la or between each emitter and external screen, which can be formed as grounded protecting grid of the fan.

As mobile part 3 of the fan is rotated as a result of turbulent output airflow intensive air mixing takes place, which provides for uniform ions concentration in the airflow.

Ion balance is provided owing to equal ionization conditions for different polarity ion emitters, as well as owing to air capacitor, which equalizes the emitters' land la emission flows.

One of the embodiments of the invented generator is designed for unipolar air polarization.

In this variant the ion emission system, which is formed with one diode and no less than one ion emitter, is connected not only to high voltage terminal of high AC voltage, but also to its low potential terminal. This additional connection is effected via conducting motor shaft, which is normally coupled with the motor body and with one of the motor supply terminals.

Fig. 2 is a scheme of generator for negative polarity ion generation in which rotor part 4 of the air capacitor is connected to anode of diode 2 and ion emitter 1, while the cathode of diode 1 is connected to the low voltage terminal of high AC voltage power supply 6 via shaft 9 of fan motor 8, and stator part 5 of air capacitor is connected to the high voltage terminal of high voltage AC power supply 6, moreover low voltage terminal of power supply 6 and supply terminals of power supply 6 and motor 8 are connected to terminal 10. 150766/3 For generation positive ions rotor part 4 of air condenser is connected to cathode of diode 2 and to ion emitter 1, while the anode of diode 1 is connected to low voltage terminal of power supply 6via shaft 9 of fan motor 8.

Unipolar air ionization variant realizes the single polarity voltage producing method from AC voltage power supply.

Method suggested for bipolar and unipolar ion generation using tangential fans with long rotor is implemented in ion generator which includes no less than two different polarity ion emitters made from thin wires, two diodes, fan rotor, rotation supports, air capacitor formed with rotor and stator parts, insulator, fan motor with shaft and terminals for motor powering, controlled AC high voltage as well as synchronizer formed with synchronizing disc and optical sensor, synchronization pulse selector and control circuit.

Fig 3 is a proposed generator circuit, in accordance with a preferred embodiment of the present invention.

The generator consists of rotor axis 11 with support 12, insulator 13, rotor part 14 and stator part 15of air capacitor, diodes 16 and 16a, different polarity ion emitters 17 and 17a, rotor 18 of the fan, synchronizing disk 19 with holes 20 and 21, motor 22 and motor shaft 23 with support 12a, terminals 24 for motor 22 powering, optical sensor 25, synchronization pulses selector 26, control circuit 27 and controlled generator of high AC voltage 28. Stator part 14 of the air capacitor is mounted on insulator 13 and is fixed to the fan body, while rotor part 15 of this capacitor is fixed on rotor 18 face opposite stator part 14 and rotor 18 is fixed on shaft 23 of motor 22 and rotates in supports (bearings) 12 and 12a, which are likewise motor 22 fixed on the fan body.

Synchronizing disk 19 is fastened on shaft 23 of motor 22, and optical sensor 25 is fastened on the fan body so that holes 20 and 21, which deteraiine the ion emitters position enter the working area of sensor 25 during rotor 18 rotation.

At the same time optical sensor 25 output is connected to the input of synchronization pulses selector 26, the outputs of which are connected to the 150766/3 control input of high AC voltage power supply 28 via control circuit 27, whereas high potential terminal of power supply 28 is connected to stator part 14 of air capacitor, and its rotor part 15 is connected to different potential terminals of diodes 16 and 16a, the other different potential terminals of the diodes are connected to ion emitters 17 and 17a, which are arranged lengthwise rotor 18.

In order to distinguish between the different polarity emitters, holes 20 and 21 in disk 19 have different length and equal height.

This enables yielding different duration electric pulses at the output of optical sensor 25 and then gate these pulses in selector 26 by duration, so that synchronization pulses reach the first output of selector 26 at the instant emitters 17 and 17a pass by a certain point on the fan body during rotor 18 rotation; synchronization pulses reach the second output of selector 26 at the instant emitter 17 passes by the same point on the fan body, while synchronization pulses reach the third output of selector 26 at the instant emitter 17a passes by the very same point on the fan body.

Control circuit 27, which is a switch, is used for selecting the generator operation mode. Optical sensor 25 is a standard modern microelectronics element and it is formed with an emitting LED-emitter and photodiode-sensor, which is a receiver.

Fig .4 is one of the possible embodiments of synchronization pulses selector 26 and controlled high AC voltage source 28.

Fig. 5 shows voltage values in different points of selector 26 and power supply 28.

Synchronization pulses selector 26 consists of operational amplifier 261, used for gating high output resistance of optical sensor 25 with low resistance of internal elements of selector 26, monostable multivibrator 262 and two gates, one formed with transistor 265 and its base resistor 263 and collector 150766/3 resistor 264, and the other one with transistor 268 and its base and collector resistors 266 and 267 respectively.

Different duration pulses from optical sensor 25 output are applied to selector 26 input (See Fig. 5a), each pulse being related to a certain ion emitter. These pulses via operational amplifier 261 trigger monostable multivibrator 262, which produces constant duration pulses, which is longer than the minimal duration of a pulse arriving from sensor 25, but shorter than maximal duration of a pulse arriving from sensor 25 (see Fig. 5b).

Pulses from output of multivibrator 262 are via control circuit 27 at the control input of power supply 28, which forms high AC voltage pulses (see Fig. 5e).

At the same time pulses from outputs of operational amplifier 261 and multivibrator 262 arrive at the first gate formed with components 263, 264, 265 and at the second gate, formed with components 266, 267, 268. Synchronization pulse appears at the collector of transistor 265 for unipolar ionization of equal polarity ions (see Fig. 5c), while synchronization pulse at transistor 268 collector serves for unipolar ionization of opposite polarity ions (see Fig. 5d).

In this way manipulating control circuit 27, namely switching the control input of power supply 28 to different outputs of selector 26 allows for ionization types (bipolar, unipolar (+), unipolar (-)).

Controlled high voltage power supply 28 is a standard radio pulses generator based on capacitor 283 discharge into the inductivity of winding of step-up transformer 284.

Capacitor 284 is charged with dc current applied to capacitor from terminals 281 via resistor 282 and primary winding of transformer 284.

Synchronization pulses from selector 26 via control circuit 27 are supplied to thyristor 285, which acts as a switch. 150766/4

Claims (19)

1. A method of ion generation and dispersion using a fan, high AC voltage source and a system for ion emission comprising no less than one ion emitter and a diode for supplying positive and negative voltage to the emitter at least one ion emitter wherein the system for ion emission is rotated in space relatively to a fixed part of the fan.

2. The method of claim 1, wherein energy from a high potential output of a high AC voltage power supply is applied to the above mentioned system for ion emission via capacitance coupling in which gas is used as a dielectric.

3. The method of claim 1, wherein in order to generate unipolar ions, energy from a low potential output of a high AC voltage power supply is supplied via an axis of the rotary part of the fan.

4. The method of claim 1, wherein in order to generate unipolar ions, energy from a low potential output of a high AC voltage power supply is supplied via a motor shaft of the fan.

5. The method of claim 1, wherein the fan comprises a tangential fan and with at least two different polarity ion emitters and two diodes, for supplying positive and negative voltage to the emitters, wherein for balancing of positive and negative ions during rotation the instant of high alternating voltage generation 150766/4 is synchronized with the instant each polarity ion emitters pass by a certain point of the fixed part of the fan.

6. The method of claim 1, wherein the fan comprises a tangential fan and with at least two different polarity ion emitters and the two above mentioned diodes , wherein for generating positive or negative ions during rotation the instant of high alternating voltage generation is synchronized with the instant of the selected polarity ion emitters pass by a certain point on the fixed part of the fan.

7. The method of claim 1, wherein the ion emitter is located on an area of the fan with minimal airflow velocity, in order to reduce dust build-up on the ion emitter.

8. An ion generator comprising a high alternating voltage source, a fan and at least one ion emitter and a diode used for supplying positive or negative voltage to the emitter, wherein the ion emitter is mounted on a rotary part of the fan.

9. The generator of claim 8, wherein air capacitor is further provided, which consists of rotor and stator parts; the rotor part thereof is mounted on the rotary part of the fan and connected to the ion emitter, and a stator part thereof is mounted on a fixed part of the fan and connected to a high potential terminal of the high alternating voltage power supply. 12 150766/3

10. The generator of claim 8, in which a low potential terminal of the high alternating voltage power supply is connected to the ion emitter via a motor shaft of the fan.

11. The generator of claim 8, in which a low potential tenninal of the high alternating voltage power supply is connected to the ion emitter via an axis of the rotary part of the fan.

12. The generator of claim 9, comprising at least two different polarity ion emitters and two diodes, in which for bipolar ionization the rotor part of the capacitor is connected to two different polarity terminals of the diodes, while the other different polarity terminals of the above diodes are connected to the ion emitters.

13. The generator of claim 9, wherein for positive polarity ion generation the rotary part of the capacitor is connected to the cathode of the diode and to the ion emitter, while the anode of the diode is connected to a motor shaft

14. The generator of claim 9, wherein for positive polarity ion generation the rotary part of the capacitor is connected to the cathode of the diode and to the ion emitter, while the anode of the diode is connected to an axis of the rotary part.

15. The generator of claim 9, wherein for negative polarity ion generation the rotary part of the capacitor is connected to the anode of the diode and to the ion emitter, while the cathode of the diode is connected to a motor shaft. 13 150766/3

16. The generator of claim 9, wherein for negative polarity ion generation the rotary part of the capacitor is connected to the anode of the diode and to the ion emitter, while the cathode of the diode is connected to an axis of the rotary part.

17. The generator according to claim 1, consisting of a tangential rotor fan, controlled high alternating voltage power supply and ion emitters formed as thin wires arranged lengthwise the rotor, wherein in order to receive both bipolar and any polarity unipolar ionization the generator is further provided with a synchronizer consisting of a disk formed with at least two holes and a sensor, synchronization pulse selector and high alternating voltage power supply control circuit; the disk with holes in it is mounted on a motor shaft or on an axis of the rotary part, the" sensor mounted on a~stator part of the fan, the electric output of the sensor connected to the synchronization pulse selector and outputs of the synchronization selector being via a control circuit connected to a control input of the high alternating voltage power supply.

18. A method of ion generation and dispersion substantially as described in the present specification, drawings and claims.

19. An ion generator substantially as described in the present specification, drawings and claims. 14