KR20010095359A - A Electrostatic Air Cleaner - Google Patents

Abstract

PURPOSE: An electrostatic air cleaner is provided to increase transformation efficiency of a power supply to reduce power consumption, to improve corrosion-resistance and reduced heat generation and to prevent obstruction caused from electromagnetic wave by comprising a piezoelectric transformer to generate high potential voltage. CONSTITUTION: The air cleaner comprises a cleaner box(1); a sun filter(2) mounted at its entry part; an AC-DC adaptor(9) to transform AC into DC and output it; a high voltage supplying device(6) from the output of adaptor(9);a grid(3) and an ionization plate(4) to generate corona-arc from the high voltage of the device(6) by ionizing the contaminated air through the sun filter(2); a static electricity generation plate(5) to capture dust particles of the contaminated air ionized by the grid(3) and the ionization plate(4); and a post-filter(12) to finally filtrate residual contaminants possible to be contained in the filtered air by passing through the generation plate(5).

Description

Electrostatic Air Cleaner Using Piezoelectric Transformer {A Electrostatic Air Cleaner}

The present invention relates to an electrostatic air cleaner using a piezoelectric transformer, and more particularly, to an electrostatic air cleaner configured of a power supply device for outputting a high output voltage using the piezoelectric transformer.

In general, electrostatic air purifiers charge contaminated air entering the inlet in the ionization zone, collect the dust particles in the dust collection zone, generate negative ions and discharge them together with the cleanly purified air. It is mainly used to purify indoor air that is not very well polluted easily.

Electrostatic air purifiers purify the air by collecting charged dust particles. For this purpose, two electrodes are installed in the air cleaner, and the electrodes are used to generate corona discharge to charge electrons to charge the dust particles.

This corona discharge requires a very high voltage of about several kV between electrodes facing each other.

This is generated by the power supply, one of the most important devices in an air cleaner, and supplied by this voltage.

The power supply unit uses a transformer for boosting, which is a winding-type transformer with a core of silicon steel and wound around a coil.

The disadvantages that occur when using the winding-type transformer mainly used for the power supply of the air cleaner are as follows.

1. Heat is generated due to the incomplete insulation state of the silicon steel sheet and the copper wire of the winding-type transformer, which causes a problem in that the step-up efficiency is lowered and the insulation state is worsened due to moisture absorbed from the outside.

2. There is a risk of the transformer in the power supply igniting due to a short circuit caused by a shock occurring outside or on any part of the air cleaner.

This is because the wound-type transformer is easy to burn.

3. Wire-wound transformers often have the problem of causing electromagnetic interference.

4. High power consumption is required due to the limitation of boost voltage due to heat generation.

5. Wire-wound transformers require large volumes to convert from low input voltage to high output.

It is not suitable for portable applications such as automotive air fresheners.

The present invention is to solve the problems of the prior art as described above, to reduce the power consumption by increasing the power supply conversion efficiency for supplying a high voltage for corona discharge in the electrostatic air cleaner, strong corrosion resistance, low heat generation and electromagnetic waves It is an object of the present invention to provide an electrostatic air purifier using a small and light piezoelectric transformer by not causing an obstacle, eliminating the risk of ignition due to a short circuit, and reducing its size.

1 is a block diagram showing the overall configuration of an electrostatic air purifier using a piezoelectric transformer according to the present invention.

Figure 2 is a block diagram showing the configuration of the electrical circuit portion of the electrostatic air cleaner using the piezoelectric transformer according to the present invention.

3 is a circuit diagram showing a circuit of an electric circuit portion of an electrostatic air cleaner using a piezoelectric transformer according to the present invention.

Figure 4 is a block diagram showing the configuration of another embodiment of the present invention.

5 is a configuration diagram showing in detail a portion of another embodiment of FIG.

Explanation of symbols on the main parts of the drawings

1: box 2: line filter

3: grid 4: ionization plate

5: electrostatic generating plate 6: high voltage supply device

7, 8: conductor 9: AC-DC adapter

10 conductor 11 contaminated air

12: After filter 13: Purified air

14 piezoelectric transformer 15 input side drive unit

16 output side generator 17 limiting amplifier

18, 19: preamplifier 20, 21: power amplifier

22: feedback loop 23: antenna

24 rectifier 25 discharge electrode

In order to achieve the above object, the present invention includes a sun filter installed at the inlet of the air purifier box to filter contaminants having a relatively large particle size; An AC-DC adapter converting an AC voltage into a DC voltage and outputting the same; A high voltage supply device receiving the output voltage of the AC-DC adapter and outputting a high voltage based on a piezoelectric transformer; A grid and an ionization plate supplied with the high voltage output of the high voltage supply device to cause corona discharge to ionize and charge contaminated air flowing through the line filter; An electrostatic generating plate generating static electricity to collect dust particles of contaminated air charged and ionized by the grid and ionizing plate; Provided is an electrostatic air purifier using a piezoelectric transformer, characterized in that the filter is configured to filter the contaminants remaining in the filtered air while the charged dust particles through the electrostatic generator plate.

(Example)

The configuration and operation of the electrostatic air purifier using the piezoelectric transformer according to the present invention will be described in detail with reference to the embodiment of the present invention.

1 is a block diagram showing the overall configuration of the electrostatic air purifier using the piezoelectric transformer according to the present invention, Figure 2 shows the configuration of an electric circuit portion of the electrostatic air purifier using the piezoelectric transformer according to the present invention. 3 is a circuit diagram showing a circuit of an electric circuit part of an electrostatic air purifier using a piezoelectric transformer according to the present invention, FIG. 4 is a block diagram showing a configuration of another embodiment of the present invention, and FIG. 5 is another view of FIG. It is a block diagram which showed the Example part in detail.

The schematic configuration of the electrostatic air purifier using the piezoelectric transformer according to the present invention is installed in the inlet portion of the air purifier box 1, as shown in Figure 1 to filter the pollutants having a relatively large particle size (2); An AC-DC adapter 9 for converting and converting an AC voltage into a DC voltage; A high voltage supply device 6 receiving the output voltage of the AC-DC adapter 9 based on a piezoelectric transformer 14; A grid (3) and an ionization plate (4) for receiving the high voltage output of the high voltage supply device (6) to cause corona discharge to ionize and charge contaminated air flowing through the line filter (2); An electrostatic generating plate (5) generating static electricity to collect dust particles of contaminated air charged and ionized by the grid (3) and the ionizing plate (4); Charged dust particles while passing through the electrostatic generating plate 5 finally filter the contaminants remaining in the filtered air is composed of a filter (12).

Here, the A + portion of the output of the high voltage supply device 6 is connected to the even-numbered electrostatic generating plate of the grid and the dust collecting region, and the ionization generating plate is connected to the odd-numbered electrostatic generating plate of the dust collecting region.

In FIG. 1, reference numerals 7 and 8 are conductors for supplying a voltage output from the high voltage supply device 6 to the grid 3, the ionizing plate 4, and the electrostatic generating plate 5. It is a conducting wire between the adapter 9 and the high voltage supply device 6.

Reference numeral 11 denotes a flow of contaminated air flowing into the line filter 2, and reference numeral 13 denotes a flow of purified air passing through the post filter 12.

As shown in FIG. 2, the high voltage supply device 6 includes a piezoelectric transformer 14, a limiting amplifier 17, a preamplifier 18 and 19, a power amplifier 20 and 21, a feedback loop 22, and a rectifier. It consists of 24.

The input DC of the high voltage supply device 6 is connected to the output of the AC-DC adapter 9.

The output of the rectifier 24 is a positive (+) output of the high voltage supply device 6, which is connected to the static electricity generating plate 5 and the grid 3.

Then, the oscillation circuit is configured using the feedback loop 22, the amplifiers 17 to 21, and the piezoelectric transformer 14.

As shown in FIG. 3, the limiting amplifier 17 includes a CMOS loop U1 and a resistor R2, and two diodes D1 and D2 are both connected to an input of the U1.

The diode D1 is connected to the DC input point B + and the diode D2, and the diode D2 is grounded.

The preamplifier 18 made of the CMOS element U2 has an input connected to an output of the U1 and an output connected to an input of the power amplifier 20 through a resistor R3.

The preamplifier 19 is made in series with two CMOS elements U3, 4.

The input of this amplifier is connected to the output of U1 and is connected to the input of the power amplifier 21 via a resistor R4.

The power amplifier 20 consists of a MOSFET element Q1, an inductor L1, which is connected to the B + point of the input DC and also to the drain of Q1.

The source of Q1 is grounded. The gate of Q1 is the input of the power amplifier 20, and the junction of the drain of Q1 and L1 is the output.

The power amplifier 21 is composed of Q2 and inductor L2.

Q2 and L2 are the same as Q1 and L1, and are connected in the same manner.

The feedback loop 22 is composed of an antenna 23 and a resistor R1, and the antenna 23 is connected to an input of U1 through a resistor R1.

Capacitor C1 is connected in parallel to the input side driver of the piezoelectric transformer 14.

The output side generator 16 of the piezoelectric transformer 14 is connected to the input of the rectifier 24.

Rectifier 24 is composed of diodes D3, D4, and capacitor C2.

The cathode of diode D4 is grounded and the anode is connected to the cathode of D3.

Capacitor C2 is connected to the anode of D3 and grounded.

The connecting portion of D3, 4 becomes the input portion of the rectifier 24, and the connecting portion of D3, C2 becomes the output portion A + portion of the rectifier 24.

The air purifier works by connecting to AC power through the adapter.

In FIG. 1, the air 11 contaminated by the ventilation device or the natural flow passes through the inlet of the air cleaner, through the filter 2, the ionization zone, and the dust collection zone continuously.

The applied DC electricity generates the output voltage at the generator 16 of the piezoelectric transformer 14 via the inductors L1, 2 past the B + point, where the AC voltage also appears at the antenna 23. Depending on the polarity of the antenna signal, rectifier U1 generates a negative or positive output voltage, which in turn regulates the flow through U2 of the preamplifier to transistor Q1, or through U3 and 4 to transistor Q2, which translates the antenna signal value. Amplify each time.

This means that the feedback moves in the positive direction.

In consideration of this, the piezoelectric transformer 14 is connected to the piezoelectric transformer 14, the rectifiers U1, U2 and the transistor Q1 (or U1, U3, U4 and transistor Q2) as a resonant device, and oscillates and operates by a resonance frequency.

The oscillation step of converting the sinusoidal waveform of the antenna into a rectangular waveform signal and making it stable.The inverter U3 rotates the output signal of U1 180 degrees and compares it with the input of U2.The push-pull operates the transistors Q1 and Q2. Provide a push-pull step.

High voltage AC is generated on the output side of the generator 16 while the piezoelectric transformer 14 is operating in a stabilized state. The high voltage AC is converted to 5,000 to 6,000 V DC by the rectifier 24.

The converted high voltage is applied between the ionization plate 4 and the grid 3 in the ionization region, the density around the grid is high and a corona discharge is generated.

Dust particles in contaminated air are charged in the corona area by positive charges.

The charged particles flow into the dust collecting region of the electrostatic plate 5 electric field and collect on the surface of the dust collecting plate.

The remaining contaminated particles are then removed through the filter 12 and clean air 13 purged out.

Humidity in the equipment, or moisture contained in the dust particles collected in the dust collection region, changes the reactive load value of the high voltage supply, resulting in an output voltage range of 5,000 to 6,000V.

Medium or portable electrostatic air cleaners operate optimally at output voltages ranging from 4,500 to 7,500V.

This range is not too narrow between the electrodes of the ionization region, and does not generate dangerous levels of ozone.

It has the highest efficiency when the operating frequency of the high voltage supply device 6 and the resonance frequency of the piezoelectric transformer 14 coincide.

Adjustment of the operating frequency is made by selecting a value of L1 equal to that of inductor L2.

That is, it is necessary to consider appropriate selection for the capacitor C1 connected in parallel with the capacitance of the crystal oscillator inductor L1 (or L2) and the piezoelectric transformer 14 driver 15.

After selection of the value of L1 = L2, the maximum output voltage is produced at the output of the piezoelectric transformer 14 by the change of the capacitor C1 value.

The next step is the optimum phase shift in the feedback loop.

This can be obtained by selecting the antenna position according to the length of the generator and selecting the resistor R1.

The optimal antenna position is near the center of the generating portion of the piezoelectric transformer 14 operating in the secondary mode.

The amplification value of the amplifier U1 is determined by the ratio of R2 / R1.

The piezoelectric transformer 14 has the maximum output voltage value by adjusting the phase shift and the U1 amplification value.

Diodes D1 and D2 protect U1 from DC input (B +) and ground.

4 is a view showing another embodiment of the present invention, in which a discharge electrode 25 is further arranged at an outlet portion where fresh air is discharged.

This electrode is connected to the output A- of the high voltage supply device 6.

5 is a circuit diagram of the added high voltage output device.

The added rectifier 28 is connected to the output side of the generator 16 of the piezoelectric transformer 14 via a resistor R5.

The rectifiers are arranged in conjunction with six more well-known rectifiers. The rectifiers D5 to D10 and capacitors C3 to C8 are connected asymmetrically. The output point A- of this rectifier has a negative polarity.

The electrostatic air purifier is operated in the manner described above and clean air 13 flows through the filter 12 after the outlet and generates a DC voltage in the range of 14,000-17,000 V at the cathode of the added rectifier.

This voltage generates negative ions 27 by the corona discharge generated at the discharge electrode 25.

Negative ions are discharged out with clean air decontaminated. The required output voltage of 14,000 to 17,000 V is obtained by changing the R5 value.

It can be seen that the maximum negative ions usually occur at a voltage of 14,000-17,000V.

If the voltage is lower than this, the number of negative ions produced is drastically reduced. On the contrary, at higher voltages, the ozone molecules increase rapidly.

Ozone molecules are known to be very harmful to humans, and devices that generate them are advised to keep the ozone concentration as low as possible.

On the other hand, in order to sufficiently charge the dust particles, 0.02 to 0.2 seconds should remain in the ionization region.

Therefore, the length of the ionization region should be longer than 0.2V. Where V is the flow rate in the air cleaner.

The length of the collecting plate in the direction of air flow in the collecting region is also important. The length of this plate depends on the operating conditions, such as the clean range of the air cleaner, the concentration of dust, and how often it is used.

It is important that the additional discharge electrode 25 for generating negative ions is made of a material, has a strong corrosion resistance and a small size, and may be made of tungsten, detanium, and molybdenum.

The diameter of the electrode wire is preferably about 0.2 to 0.5 mm.

4 and 5, the actual air cleaner is constructed based on the above description, and the ionization region and the dust collection region are arranged in the above-described manner.

Amplifiers U1, U2, U3, and U4, including diodes D1 and D2, are controlled by a 4069 type logic integrated circuit hex buffer inverter.

The piezoelectric transformer has a two-stage structure of secondary vibration mode, 1.4 mm thick, 14 mm wide, and 80 mm long, made of PZT (lead-zirconium-titanium) ceramic.

The resonant frequency of this transformer is 42.3kHz, the operating frequency of all high voltage supplies, and the input DC voltage is 12V. At the A + point, the output DC voltage is 5,000V and the current is 0.1mA.

This is the current value when operating in very contaminated air conditions. At the A-point, the output DC voltage is 16,000 V, and the current flowing through the discharge electrode 25 is 30 mA.

The DC current input under this condition is 98mA, and the total power conversion efficiency is 83%. At this time, the piezoelectric transformer has 91% conversion efficiency.

In long operation, the surface temperature of the piezoelectric transformer rises by 5 ° C.

When measured at a distance of 1 m from the device, the concentration of anions generated is 1,200,000 per cm ³ , with an ozone concentration lower than 0.03 ppm.

The air purifier according to the present invention can be seen that the output characteristics such as ozone or anion concentration is better compared to the well-known portable device through the above-described information.

Electrostatic air purifier using the piezoelectric transformer according to the present invention made as described above has a high insulation, corrosion resistance, moisture resistance of the high voltage supply device, and does not use a copper wire coil in the transformer does not cause electromagnetic interference, at a low temperature It has high conversion efficiency and low power consumption.

Also, there is no risk of fire when shorted. In conclusion, it has a thin and light weight, which makes it suitable for the requirements of electrical appliances.

Claims (4)

In the electrostatic air purifier, A sun filter installed at an inlet of the air purifier box to filter contaminants having a relatively large particle size; An AC-DC adapter converting an AC voltage into a DC voltage and outputting the same; A high voltage supply device receiving the output voltage of the AC-DC adapter and outputting a high voltage based on a piezoelectric transformer; A grid and an ionization plate supplied with the high voltage output of the high voltage supply device to cause corona discharge to ionize and charge contaminated air flowing through the line filter; An electrostatic generating plate generating static electricity to collect dust particles of contaminated air charged and ionized by the grid and ionizing plate; Electrostatic air purifier using a piezoelectric transformer, characterized in that consisting of a filter after the final filter of the contaminants remaining in the filtered air is charged dust particles through the electrostatic generating plate. The electrostatic air purifier using the piezoelectric transformer according to claim 1, wherein the length of the ionization region by the grid and the ionizing plate should be longer than 0.2V (air flow rate in the air purifier). The electrostatic air purifier of claim 1, wherein the high voltage supply device comprises a piezoelectric transformer, a limiting amplifier, a preamplifier, a power amplifier, a feedback loop, and a rectifier. The rectifier of claim 1, wherein an additional six rectifiers are connected to an output of the piezoelectric transformer to generate a DC voltage of 14,000 to 17,000 V, and the discharge electrode is disposed at an air outlet through which clean air passes through the filter. Connected to the electrostatic air purifier using a piezoelectric transformer, characterized in that the corona discharge around the discharge electrode to generate negative ions to be discharged with clean air.