Electric precipitator and air cleaner having the same

Disclosed herein are an electric precipitator, which efficiently charges dust particles without lowering dust collecting efficiency, although a velocity of an air current is not uniform, and an air cleaner having the same. The electric precipitator includes a charger unit including at least two charge cells to charge dust particles contained in air, and a collector unit to collect the dust particles charged by the charger unit. The at least two charge cells include a first cell, through which the dust particles pass at a first velocity, and a second cell, through which the dust particles pass at a second velocity different from the first velocity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2009-0102583, filed on Oct. 28, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

Embodiments relate to an electric precipitator, which efficiently charges dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and an air cleaner having the same.

2. Description of the Related Art

In general, electric precipitators are apparatuses, which are mounted in air conditioners, etc., and collect contaminants, such as dust, contained in air so as to purify air.

Among dust collection methods of these electric precipitators, a 2-stage dust collection method in which a charger unit and a collector unit are separately disposed has been widely employed.

In such a 2-stage dust collection method, the charger unit is configured such that a cell formed by a high voltage discharge electrode and counter electrodes is repeatedly installed at the same interval, and the collector unit is configured such that high voltage electrodes and low-voltage electrodes are arranged in parallel to form an electric field.

The high voltage discharge electrodes of the charger unit generally have the shape of a wire, a flat panel, or a needle, and in order to improve discharge characteristics, may have a specific shape. Further, the counter electrodes of the charger unit are installed such that they are separated from the high voltage discharge electrodes by a designated distance and flat surfaces thereof are parallel with an air flow direction.

Such a charger unit serves to charge dust particles, contained in air introduced into the electric precipitator, with positive or negative polarity by corona discharge.

That is, since the counter electrodes are grounded and thus have zero potential, when high voltage of positive polarity or negative polarity is applied to the discharge electrodes, corona discharge occurs between the discharge electrodes and the counter electrodes, dust particles contained in air are charged with positive or negative polarity by the corona discharge, and the charged dust particles move along an air flow to and are collected in the collector unit.

However, when an air flow passing through the electric precipitator is made using an air blower device, dust collecting efficiency of the electric precipitator in some cells having a high velocity of an air current is rapidly lowered. Therefore, the efficiency of the electric precipitator in regions having a high velocity of the air current is lowered, and thus application of the electric precipitator to an air cleaner is hard.

Further, since respective cells are arranged at the same interval in the charger unit of the conventional electric precipitator, dust particles contained in air in cells having a high velocity of the air current may not be sufficiently charged and energy higher than energy required to charge the particles may be input to cells having a low velocity of the air current. Therefore, energy beyond what is required is input, and thus energy efficiency is lowered.

SUMMARY

Therefore, it is one aspect to provide an electric precipitator, which efficiently charges dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and an air cleaner having the same.

It is another aspect to provide an electric precipitator, which improves charging efficiency and dust collecting efficiency even if a velocity of an air current passing through a charger unit is not uniform, and an air cleaner having the same.

In accordance with one aspect, an electric precipitator includes a charger unit including at least two charge cells to charge dust particles contained in air, and a collector unit to collect the dust particles charged by the charger unit, wherein the at least two charge cells include a first cell, through which the dust particles pass at a first velocity, and a second cell, through which the dust particles pass at a second velocity different from the first velocity, and the first cell and the second cell respectively charge the dust particles with different charging efficiencies.

If the first velocity is higher than the second velocity, an interval of the first cell may be shorter than an interval of the second cell.

If the first velocity is higher than the second velocity, a thickness of a discharge electrode of the first cell may be greater than a thickness of a discharge electrode of the second cell.

If the first velocity is higher than the second velocity, electrical resistance of a discharge electrode of the first cell may be smaller than electrical resistance of a discharge electrode of the second cell.

The at least two charge cells may include flat panel-shaped counter electrodes, and discharge electrodes, each of which is arranged at a central position of the neighboring counter electrodes in parallel with the counter electrodes.

The discharge electrodes may include discharge wires.

In accordance with a further aspect, an electric precipitator includes a charger unit to charge dust particles contained in air, and a collector unit including at least two dust collection cells to collect the dust particles charged by the charger unit, wherein the at least two charge cells include a first cell, through which the dust particles pass at a first velocity, and a second cell, through which the dust particles pass at a second velocity different from the first velocity.

If the first velocity is higher than the second velocity, an interval of the first cell may be shorter than an interval of the second cell.

The at least two dust collection cells may be formed by alternately stacking high voltage electrodes and low voltage electrodes to collect the dust particles.

In accordance with another aspect, an electric precipitator includes a charger unit including a plurality of charge cells to charge dust particles contained in air, a collector unit including a plurality of dust collection cells to collect the dust particles charged by the charger unit, and an air blower device installed at one side of the plurality of charge cells and the plurality of dust collection cells to form an air current within the plurality of charge cells and the plurality of dust collection cells.

In accordance with another aspect, an electric precipitator includes a charger unit to charge dust particles contained in air, a collector unit to collect the dust particles charged by the charger unit, and an air blower device to form an air current in the charger unit and the collector unit, wherein at least one of the charger unit and the collector unit includes a plurality of first electrodes arranged at different intervals according to velocities of the air current, and a plurality of second electrodes, each of which is arranged at a central position of the neighboring first electrodes in parallel with the plurality of first electrodes.

The plurality of first electrodes and the plurality of second electrodes may respectively form counter electrodes and discharge electrodes to generate corona discharge, thus forming the charger unit, and the discharge electrodes may respectively have different thicknesses.

The plurality of first electrodes and the plurality of second electrodes may respectively form counter electrodes and discharge electrodes to generate corona discharge, thus forming the charger unit, and the discharge electrodes may respectively have different electrical resistances.

The plurality of first electrodes and the plurality of second electrodes may respectively form high voltage electrodes and low voltage electrodes alternately arranged, thus forming the collector unit.

In accordance with another aspect, an air cleaner includes a main body provided with discharge holes formed through the upper surface thereof, a suction grill connected to the main body and provided with suction holes, through which air is inhaled into the main body, an air blower device mounted within the main body to forcibly circulate external air to the inside of the main body, and an electric precipitator arranged at the rear of the suction grill to charge dust particles in the inhaled air using high voltage and then collect the charged dust particles, wherein the electric precipitator includes a charger unit including a plurality of charge cells to charge dust particles contained in air, and a collector unit including a plurality of dust collection cells to collect the dust particles charged by the charger unit, and charging efficiencies or dust collecting efficiencies in at least one of the plurality of charge cells and the plurality of dust collection cells are different according to velocities of the air current.

At least one of the plurality of charge cells and the plurality of dust collection cells may include a plurality of first electrodes arranged at different intervals according to velocities of the air current, and a plurality of second electrodes, each of which is arranged at a central position of the neighboring first electrodes in parallel with the plurality of first electrodes.

The plurality of charging cells may include counter electrodes and discharge electrodes to generate corona discharge, and the discharge electrodes may respectively have different thicknesses.

The plurality of charging cells may include counter electrodes and discharge electrodes to generate corona discharge, and the discharge electrodes may respectively have different electrical resistances.

The plurality of first electrodes and the plurality of second electrodes may respectively form discharge electrodes and counter electrode alternately arranged, thus forming the charger unit to charge the dust particles.

The plurality of first electrodes and the plurality of second electrodes respectively form high voltage electrodes and low voltage electrodes alternately arranged, thus forming the collector unit to collect the dust particles.

DETAILED DESCRIPTION

FIG. 1is a view illustrating a fundamental principle of a 2-stage electric precipitator, andFIG. 2is a perspective view of the 2-stage electric precipitator.

As shown inFIGS. 1 and 2, an electric precipitator1includes a charger unit10to charge dust particles contained in air, and a collector unit20to collect dust particles charged by the charger unit10.

The charger unit10includes discharge electrodes100forming a positive pole by a high voltage power supply30, and counter electrodes200installed above and below the discharge electrodes100by a designated height difference and forming a negative pole.

A DC voltage is applied to the discharge electrodes100, thereby generating corona discharge between the discharge electrodes100and the counter electrodes200.

These discharge electrodes100may include thin discharge wires made of tungsten. However, the discharge electrodes100may have the shape of a flat panel or a needle, as well as the shape of the wire. Further, the counter electrodes200may have the shape of a flat panel.

Therefore, the high voltage power supply30applies high voltage to the discharge electrodes100, current starts to flow due to a high potential difference between the discharge electrodes100and the counter electrodes200and thus corona discharge is generated, thereby charging dust particles contained in flowing air as shown by arrow.

The collector unit20is formed by alternately stacking high voltage electrodes21and low voltage electrodes22in order to collect the dust particles charged by the charger unit10.

High voltage of positive polarity is applied to the high voltage electrodes21by a high voltage power supply40, and the low voltage electrodes22are grounded to form an electric field.

Accordingly, when dust particles contained in air are charged with positive polarity by corona discharge generated in the charger unit10, the dust particles charged with positive polarity are collected by the low voltage electrodes22having relatively negative polarity of the collector unit22due to Coulomb force.

The high voltage power supplies30and40may have positive polarity or negative polarity, or may supply pulse voltage. Here, reference numeral50represents an air blower unit to generate a velocity of the air current in the electric precipitator.

FIG. 3is a longitudinal-sectional view of an electric precipitator in accordance with one embodiment, andFIG. 4is an enlarged longitudinal-sectional view of a charger unit of the electric precipitator shown inFIG. 3.

As shown inFIGS. 3 and 4, a charger unit10-1of an electric precipitator1-1in accordance with one embodiment includes discharge wires110,120,130,140, and150, and counter electrodes210,220,230,240,250, and260to generate corona discharge.

The counter electrodes210˜260are stacked at different intervals according to velocities V of the air current, and the discharge wires110˜150are arranged at central positions between the neighboring counter electrodes210˜260.

In such a charger unit10-1, charge cells310,320,330,340, and350, each of which includes one of the discharge wires110˜160and a pair of the counter electrodes210˜260, are repeatedly formed. Here, the intervals between the counter electrodes210˜260in the respective charge cells310˜350are different according to the velocities V of the air current.

For convenience of description, among the charge cells310˜350, the charge cell formed by the first and second counter electrodes210and220and the first charge wire110is referred to as a first charge cell310, the charge cell formed by the second and third counter electrodes220and230and the second charge wire120is referred to as a second charge cell320, the charge cell formed by the third and fourth counter electrodes230and240and the third charge wire130is referred to as a third charge cell330, the charge cell formed by the fourth and fifth counter electrodes240and250and the fourth charge wire140is referred to as a fourth charge cell340, and the charge cell formed by the fifth and sixth counter electrodes250and260and the fifth charge wire150is referred to as a fifth charge cell350.

Dust particles contained in air pass through the first charge cell310at a first velocity V1, pass through the second charge cell320at a second velocity V2, pass through the third charge cell330at a third velocity V3, pass through the fourth charge cell340at a fourth velocity V4, and pass through the fifth charge cell350at a fifth velocity V5. Here, sizes of the respective velocities V1˜V5may satisfy the equation of V3>V2= or ≈V4>V1= or ≈V5, and the second velocity V2and the fourth velocity V4are the mean velocity.

In order to satisfy the above velocity distribution in the charger unit10-1of the electric precipitator1-1in accordance with this embodiment, if the interval between the second counter electrode220and the third counter electrode230forming the second charge cell320and the interval between the fourth counter electrode240and the fifth counter electrode259forming the fourth charge cell340are respectively D, the interval between the first counter electrode210and the second counter electrode220forming the first charge cell310and the interval between the fifth counter electrode250and the sixth counter electrode260forming the fifth charge cell350are respectively D+A, and the interval between the third counter electrode230and the fourth counter electrode240forming the third charge cell330is D−B. Here, A and B may have different values or the same value.

That is, in the charger unit10-1of the electric precipitator1-1in accordance with this embodiment, the intervals between the neighboring counter electrodes210˜260have different values, i.e., D, D+A, and D−B, according to the distribution of velocities V of the air current. The interval between the counter electrodes230and240in the charge cell330having a high velocity of the air current is shorter than that in the charge cells320and340having the mean velocity, and the interval between the counter electrodes210and220and the interval between the counter electrodes250and260in the charge cells310and350having a low velocity of the air current is longer than that in the charge cells320and340having the mean velocity.

On the assumption that the efficiency of the collector unit20of the electric precipitator1-1is regular, the higher the particle charging efficiency of the charger unit10-1due to corona discharge, the higher is the dust collecting efficiency of the electric precipitator1-1. This is because the charging efficiency of the charger unit10-1is in direct proportion to discharge current of the charger unit10-1, and is in inverse proportion to the intervals between the neighboring electrodes210˜260(or, intervals between the neighboring discharge wires110˜150and counter electrodes210˜260. Therefore, the shorter the intervals between the counter electrodes210˜260and the longer the discharge current of the charger unit10-1, the higher is the particle charging efficiency.

Further, when the velocity of the air current passing through the charger unit10-1is high, a moving velocity of the dust particles passing through the charger unit10-1is increased and the particle charging efficiency is lowered.

Therefore, in the third charge cell330having the third velocity V3, i.e., the highest velocity, the interval between the third and fourth counter electrodes230and240is decreased the most, and the decrease in a charge amount due to the velocity of the air current is compensated for by the increase in corona current.

Further, in the first and fifth charge cells310and350having the first and fifth velocities V1and V5, i.e., the lowest velocity, the interval between the first and second counter electrodes210and220and the interval between the fifth and sixth counter electrodes250and260are increased the most, and thus although the corona current decreases, sufficient particle charging efficiency is achieved due to the low velocity.

In the same manner, in the second and fourth charge cells320and340having the second and fourth velocities V2and V4, i.e., the mean velocity, the interval between the second and third counter electrodes220and230and the interval between the fourth and fifth counter electrodes240and250respectively have the mean value D, and thus sufficient particle charging efficiency is obtained.

Therefore, the charging efficiencies of the first charge cell310, the second charge cell320, the third charge cell330, the fourth charge cell340, and the fifth charge cell350may be maintained similarly by adjusting intervals between the neighboring electrodes210˜260according to the velocities of the air current.

Thus, the electric precipitator1-1including the charger unit10-1in accordance with this embodiment efficiently charges dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and efficiently divides total energy according to the respective charge cells310˜350of the charge unit10-1, thereby improving total energy efficiency.

Hereinafter, a further embodiment will be described with reference toFIG. 5. Some parts in this embodiment, which are substantially the same as those in the former embodiment shown inFIG. 3, are denoted by the same reference numerals even though they are depicted in different drawings, and a detailed description thereof will thus be omitted.FIG. 5is a view illustrating a portion of an electric precipitator in accordance with this embodiment.

A charger unit10-2of an electric precipitator1-2in accordance with this embodiment includes discharge wires410˜450and counter electrodes210˜260to generate corona discharge. The counter electrodes210˜260are stacked at uniform intervals, and the discharge wires410˜450are arranged at central positions between the neighboring counter electrodes210˜260.

In the electric precipitator1-2in accordance with this embodiment, if velocities of air currents passing through respective charge cells310˜350of the charger unit10-2are different, the discharge wires410˜450of the respective charge cells310and350of the charger unit10-2have different diameters, and thus particle charging efficiencies of the respective charge cells310and350of the charger unit10-2are different.

When the diameters of the discharge wires410˜450are increased, intervals between the surfaces of the respective discharge wires410˜450and the surfaces of the counter electrodes210˜260become narrow, a corona current amount is increased, and particle charging efficiency is increased. On the contrary, when the diameters of the discharge wires410˜450are decreased, the corona current amount is decreased, and particle charging efficiency is decreased.

Therefore, in the third charge cell330having the third velocity V3, i.e., the highest velocity, the diameter of the third discharge wire430is increased, and thus decrease in a charge amount due to the velocity of the air current is compensated for by corona current increase.

Further, in the first and fifth charge cells310and350having the first and fifth velocities V1and V5, i.e., the lowest velocity, the diameters of the first and fifth discharge wires410and450are decreased, and thus although corona current decreases, sufficient particle charging efficiency is achieved due to the low velocity.

In the same manner, in the second and fourth charge cells320and340having the second and fourth velocities V2and V4, i.e., the mean velocity, the diameters of the second and fourth discharge wires420and440respectively have the mean value, and thus sufficient particle charging efficiency is obtained.

Therefore, the charging efficiencies of the first charge cell310, the second charge cell320, the third charge cell330, the fourth charge cell340, and the fifth charge cell350may be maintained similarly by varying the diameters of the discharge wires410˜450according to the velocities of the air current. Thus, the electric precipitator1-2in accordance with this embodiment efficiently charges dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and efficiently divides total energy according to the respective charge cells310˜350of the charge unit10-2, thereby improving total energy efficiency.

Hereinafter, another embodiment will be described with reference toFIG. 6. Some parts in this embodiment, which are substantially the same as those in the former embodiment shown inFIG. 3, are denoted by the same reference numerals even though they are depicted in different drawings, and a detailed description thereof will thus be omitted.FIG. 6is a view illustrating a portion of an electric precipitator in accordance with this embodiment.

A charger unit10-3of an electric precipitator1-3in accordance with this embodiment includes discharge wires510˜550and counter electrodes210˜260to generate corona discharge. The counter electrodes210˜260are stacked at uniform intervals, and the discharge wires510˜550are arranged at central positions between the neighboring counter electrodes210˜260.

In the electric precipitator1-3in accordance with this embodiment, if velocities of air currents passing through respective charge cells310˜350of the charger unit10-3are different, the discharge wires510˜550of the respective charge cells310and350of the charger unit10-3have different electrical resistances, and thus particle charging efficiencies of the respective charge cells310and350of the charger unit10-2are different.

If the discharge wires510˜550of the respective charge cells310˜350of the charger unit10-3are installed in parallel and the electrical resistances of the respective charge cells310˜350are equal or substantially equal, when a designated voltage is applied to the charger unit10-3by the high voltage power supply30, voltage and current applied to the respective charge cells310˜350are equal or substantially equal. However, if the discharge wires510˜550of the respective charge cells310and350of the charger unit10-3have different electrical resistances, voltages applied to the respective charge cells310˜350are equal or substantially equal but currents applied to the respective charge cells310˜350are different according to the electrical resistances. By varying corona current amounts of the respective charge cells310˜350of the charger unit10-3in this way, the electric precipitator1-3in accordance with this embodiment obtains the same effects as the electric precipitator1-1in accordance with the embodiment shown inFIG. 3and the electric precipitator1-2in accordance with the embodiment shown inFIG. 5.

That is, if the velocity of the air current in the third charge cell330is the highest, the third discharge wire530has the smallest electrical resistance X[Ω], and thus decrease in a charge amount due to the velocity of the air current is compensated for by corona current increase.

Further, if the velocities of the air current in the first and fifth charge cells310and350are the lowest, the first and fifth discharge wires510and550have the greatest electrical resistance Y[Ω], and thus although corona current decreases, sufficient particle charging efficiency is achieved due to the low velocity.

In the same manner, if the velocities of the air current in the second and fourth charge cells320and340are the mean, the second and fourth discharge wires520and540have the mean electrical resistance Z[Ω], and thus sufficient particle charging efficiency is obtained.

Therefore, the charging efficiencies of the first charge cell310, the second charge cell320, the third charge cell330, the fourth charge cell340, and the fifth charge cell350may be maintained similarly by varying the electrical resistances of the discharge wires510˜550according to the velocities of the air current. Thus, the electric precipitator1-3in accordance with this embodiment efficiently charges dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and efficiently divides total energy according to the respective charge cells310˜350of the charge unit10-3, thereby improving total energy efficiency.

Hereinafter, yet another embodiment will be described with reference toFIG. 7. Some parts in this embodiment, which are substantially the same as those in the former embodiment shown inFIG. 3, are denoted by the same reference numerals even though they are depicted in different drawings, and a detailed description thereof will thus be omitted.FIG. 7is a view illustrating a portion of an electric precipitator in accordance with this embodiment.

A collector unit20-1of an electric precipitator1-4in accordance with this embodiment includes high voltage electrodes710˜750and low voltage electrodes810˜860to collect dust particles charged by a collector unit (not shown).

The low voltage electrodes810˜860are stacked at different intervals according to velocities V1, V2, V3, V4, and V5of the air current, and the high voltage electrodes710˜760are arranged at central positions between the neighboring low voltage electrodes810˜860.

In such a collector unit20-1, dust collection cells610˜650, each of which consists of one of the high voltage electrodes710˜760and a pair of the low voltage electrodes810˜860, are repeatedly formed. Here, the intervals between the neighboring low voltage electrodes810˜860in the respective dust collection cells310˜350may be different according to velocities V1, V2, V3, V4, and V5of the air current.

That is, in the third dust collection cell630having the third velocity V3of the air current, i.e., the highest velocity, the interval between the third and fourth low voltage electrodes830and840is decreased the most, and thus the decrease in a charge amount due to the velocity of the air current is compensated for by Coulomb force increase.

Further, in the first and fifth dust collection cells610and650having the first and fifth velocities V1and V5of the air current, i.e., the lowest velocity, the interval between the first and second low voltage electrodes810and820and the interval between the fifth and sixth low voltage electrodes850and860are longest wide, and thus although Coulomb force decreases, sufficient particle charging efficiency is achieved due to the low velocity.

In the same manner, in the second and fourth dust collection cells620and640having the second and fourth velocities V2and V4of the air current, i.e., the mean velocity, the interval between the second and third low voltage electrodes820and830and the interval between the fourth and fifth low voltage electrodes840and850respectively have the mean value, and thus sufficient particle charging efficiency is obtained.

Therefore, the dust collecting efficiencies of the first dust collection cell610, the second dust collection cell620, the third dust collection cell630, the fourth dust collection cell640, and the fifth dust collection cell650may be maintained similarly by varying the intervals between the neighboring low voltage electrodes810˜860according to the velocities of the air current.

Thus, the electric precipitator1-4in accordance with this embodiment efficiently collects dust particles even in a region having a high velocity of an air current without lowering dust collecting efficiency, and efficiently divides total energy according to the respective dust collection cells610˜650of the collector unit20-1, thereby improving total energy efficiency.

The above-described respective embodiments may be separately executed, or combinations of at least some of the respective embodiments may be executed.

Hereinafter, an air cleaner, to which an electric precipitator in accordance with one embodiment is applied, will be described.FIG. 8illustrates the air cleaner in accordance with this embodiment.

As shown inFIG. 8, an air cleaner2in accordance with this embodiment includes a main body3provided with discharge holes3a, through which air is discharged to the outside of the main body3, formed through the upper surface thereof, a suction grill4connected to the main body3and provided with suction holes, through which air is inhaled into the main body3, an air blower device5mounted within the main body3to forcibly circulate external air to the inside of the main body3, an air filter6arranged on the rear surface of the suction grill4to filter out dust particles having a high volume from inhaled air, and an electric precipitator1arranged at the rear of the air filter6to charge dust particles contained in the inhaled air using high voltage and then collect the charged dust particles.

The air cleaner2inhales external air through operation of the air blower device5, converts the inhaled air into clean air through the air filter6and the electric precipitator1, and then discharges the clean air to the outside of the main body3.

That is, when power is applied to the air blower device5and the electric precipitator1installed in the main body3, the air blower device5is driven such that external air is inhaled to the inside of the air cleaner2. After the external air is inhaled into the main body3through the suction holes4aformed through the suction grill4, relatively large dust particles are filtered out by the air filter6, and then fine dust particles are filtered out by the electric precipitator1.

Here, when power is applied to the electric precipitator1, the electric precipitator1ionizes fine dust particles passing therethrough due to corona discharge, and then collects charged dust particles, thereby removing the fine dust particles contained in air.

At this time, when the air blower device5is driven to inhale external air, the external air is inhaled at a relatively high velocity in some portions and is inhaled at a relatively low velocity in other portions. Such a velocity difference causes a charger unit (not shown) of the electric precipitator1to have different charging efficiencies (or causes a collector unit (not shown) to have different dust collecting efficiencies), thereby allowing the electric precipitator1to effectively divisionally use total energy.

As is apparent from the above description, in an electric precipitator and an air cleaner in accordance with one embodiment, charging efficiencies or dust collecting efficiencies in a charge unit or a collector unit are varied according to characteristics of an air current passing through the electric precipitator, thereby efficiently charging dust particles even in a region having a high velocity of the air current and allowing total energy to be efficiently divisionally used according to respective cells.