Air conditioner with electrostatic dust collector

Abstract

 An air conditioner includes an air filter disposed on a suction side of an air flow path, an electrostatic dust collecting unit, and an electrostatic charge portion disposed in the electrostatic dust collecting unit, including an earth electrode, a needle-shaped discharge electrode to which a high voltage is applied, and an outer frame for protecting the needle-shaped discharge electrode and the earth electrode. The electrostatic dust collecting unit is installed upstream of the air filter so that a discharge area thereof is formed upstream of the air filter or is disposed near an air discharge opening in the air flow path so that a discharge area thereof is formed approximate on the front side of the air discharge opening.

Description

[0001] The present invention relates to an air conditioner having an electrostatic particle collecting unit capable of collecting airborne dust or the like; and, more particularly, to an air conditioner having a high-performance electrostatic particle collecting unit which is configured to have features suitable for an air conditioning system.

[0002] As shown in Fig. 6, indoor unit 1 of a conventional air conditioner includes heat exchanger 4 and blower 5 in a main body thereof. Room air is drawn into the main body of indoor unit 1 by blower 5 and is blown back out to the room through air discharge opening 6 by blower 5 after being heated (or cooled as necessary) by heat exchanger 4.

[0003] Recently, in addition to a room air heating or cooling function an indoor air conditioning system is configured to perform an additional task of purifying indoor air by collecting airborne pollutants such as dust or the like.

[0004] The indoor air contains very fine airborne pollutants, so it is highly likely that hay fever, allergic reaction or the like is caused by these airborne pollutants. Further, if the airborne pollutants are accumulated, it will result in more serious problems such as dust mite. Thus, it is necessary to provide purified clean air by adding an air purifying function to a conventional air conditioning system to remove indoor airborne pollutants.

[0005] An electrostatic airborne particle collecting unit of the conventional air conditioner is installed at a certain section between an air filter called pre-filter disposed on the air inlet side of the indoor air conditioner unit and a heat exchanger, wherein the pre-filter captures relatively large-sized airborne particles.

[0006] The electrostatic airborne particle collecting unit includes a charge electrode, an earth electrode and a particle collecting portion, all of which are integrated. After being drawn through an air inlet of the indoor air conditioning unit, indoor air passes through the pre-filter, which captures large-sized dust particles and trap them on the filter. Thereafter, the electrostatic airborne particle collecting unit captures small airborne pollutants like tobacco smoke, dust and pollen. Ultimately, purified clean air is exhausted back into the room through the air discharge opening by the blower (see, for example, Japanese Utility Model Laid-Open No. S62-124421).

[0007] Further, there is proposed another air conditioner having a negative ion generator. The air conditioning system provides negative ions directly into the room or along with heated (or cooled) air.

[0008] The negative ions supplied to the room are absorbed by the human body, and serves to activate cellular tissues and accelerate the discharge of waste matters from the body, thereby facilitating metabolism (see, for example, Japanese Patent Laid-Open Application Nos. H11-72240 and 2001-74265).

[0009] Moreover, in a conventional electrostatic air purifier, a corona discharge is generated between a needle-shaped electrode to which a high voltage is applied and a matching electrode which is earthed, so that airborne particles are charged by thus formed strong electrostatic field. However, in order to reduce power consumption and the amount of ozone generation, there is proposed an electrostatic air purifier capable of cleaning air by charging airborne dust particles by a dust collecting unit which discharges negative ions only, without generating a corona discharge (see, for example, International Publication WO0164349).

[0010] In the forgoing configuration of the conventional air conditioner, since the charge electrode, the earth electrode and the particle collecting portion are integrated and installed within the electrostatic particle collecting unit, the design causes increased resistance to air flow. As a result, to avoid compromising the performance of the air conditioning function, the electrostatic particle collecting unit had to be disposed only partially at the suction inlet of the indoor air conditioner. Consequently, a sufficient level of airborne pollutant collection could not be achieved for the entire air drawn into the indoor air conditioning unit by the blower.

[0011] It is, therefore, an object of the present invention to provide an air conditioner having an electrostatic dust collecting unit with a high dust collecting capacity. In accordance with the present invention, the entire indoor air drawn into the suction inlet can be purified by installing the electrostatic dust collecting unit upstream of an air filter (pre-filter) which is disposed on the suction side, along the air flow path within the air conditioner. The filter functions as a dust collecting portion.

[0012] The electrostatic dust collecting unit includes an electrostatic charge portion having a needle-shaped discharge electrode to which a high voltage is to be applied, an earth electrode and an outer frame for protecting the discharge electrode and the earth electrode.

[0013] In accordance with a first preferred embodiment of the present invention, there is provided an air conditioner including: an air filter disposed on a suction side of an air flow path; an electrostatic dust collecting unit; and an electrostatic charge portion disposed in the electrostatic dust collecting unit, including an earth electrode, a needle-shaped discharge electrode to which a high voltage is applied, and an outer frame for protecting the needle-shaped discharge electrode and the earth electrode, wherein the electrostatic dust collecting unit is installed upstream of the air filter, and a discharge area of the electrostatic dust collecting unit is formed upstream of the air filter.

[0014] With the above configuration, airborne particles drawn through the room air inlet of the air conditioner are electrostatically charged by the electrostatic charge portion. In the conventional configuration, an air filter's (also called pre-filter) function used to be limited to trapping only large-sized airborne pollutants by making the entire room air drawn into the system pass through the filter. However, in accordance with the present invention, the air conditioner has an auxiliary feature which includes an airborne particle collecting unit with the foregoing air filter being enabled to trap also small airborne particles like pollen and tobacco smoke. Ultimately, the present invention provides an efficient reduction of indoor airborne irritants and allergens, thereby supplying cleaner and fresher air to breathe.

[0015] In accordance with a second preferred embodiment of the present invention, there is provided an air conditioner including: an air filter disposed on a suction side of an air flow path; an electrostatic dust collecting unit; and an electrostatic charge portion disposed in the electrostatic dust collecting unit, including an earth electrode, a needle-shaped discharge electrode to which a high voltage is applied, and an outer frame for protecting the needle-shaped discharge electrode and the earth electrode,
wherein the electrostatic dust collecting unit is installed near an air discharge opening in the air flow path, and a discharge area of the electrostatic dust collecting unit is formed approximate on the front side of the air discharge opening.

[0016] The above configuration electrostatically charges small airborne particles in an entire indoor space, and dust collecting performance of the air filter of a suction unit is thus enhanced. Further, due to the benefits of negative ions, cellular tissues can be activated and the discharge of waste matters from the human body can be accelerated, thus improving metabolism.

[0017] Further, the air conditioner in accordance with the present invention is configured such that at least a part of the air filter disposed on the suction side of the air flow path has conductivity. As a result, the potential difference between the air filter and the charged dust particles can be increased, and the dust collecting performance can be further improved.

[0018] Moreover, the air conditioner in accordance with the present invention can be configured such that at least the air filter disposed on the suction side of the air flow path has conductive portion in the part and the conductive portion is connected to an earth of the air conditioner main body.

[0019] As a result, the potential difference between the air filter and the charged dust particles is certain to exist because the conductive air filter is earthed. Therefore, the dust collecting performance is improved.

[0020] The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

Fig. 1 is a schematic vertical cross sectional view of an indoor unit of an air conditioner including an electrostatic dust collecting unit in accordance with a first preferred embodiment of the present invention;

Fig. 2 sets forth a schematic view of the electrostatic dust collecting unit in accordance with the first embodiment of the present invention;

Fig. 3 presents a schematic vertical cross sectional view of the indoor unit of the air conditioner having an electrostatic dust collecting unit in accordance with a second preferred embodiment of the present invention;

Fig. 4 shows a schematic external view of a pre-filter in accordance with a third preferred embodiment of the present invention;

Fig. 5 depicts a schematic external view of a pre-filter in accordance with a fourth preferred embodiment of the present invention; and

Fig. 6 provides a schematic vertical cross sectional view of an air conditioner including a conventional electrostatic dust collecting unit.

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, it is to be noted that the present invention is not limited thereto.

(First preferred embodiment)

[0022] A first preferred embodiment will now be described in conjunction with Figs. 1 and 2.

[0023] Fig. 1 is a schematic vertical cross sectional view of indoor unit 1 of an air conditioner including electrostatic dust collecting unit 10 in accordance with the present invention.

[0024] In Fig. 1, reference numeral 1 represents the indoor unit of the air conditioner, 2 a suction inlet, 3 a panel, 4 a heat exchanger, 5 a blower, 6 an air discharge opening, 7 an air flow path, 10 an electrostatic dust collecting unit and 11 a pre-filter.

[0025] Fig. 2 provides a schematic view of electrostatic dust collecting unit 10.

[0026] In Fig. 2, reference numeral 12 represents needle-shaped discharge electrodes, 13 an earth electrode, 14 an outer frame and 15 an electrostatic field formed in a discharge area.

[0027] Referring to Fig. 1, room air drawn into indoor unit 1 of the air conditioner through suction inlet 2 passes through pre-filter 11 and is heated (or cooled) by heat exchanger 4. Thereafter, the purified conditioned air is exhausted back into the room through air discharge opening 6.

[0028] In indoor unit 1 of the air conditioner, electrostatic dust collecting unit 10 is disposed near suction inlet 2 which is provided upstream of heat exchanger 4 and pre-filter 11 in air flow path 7 of indoor unit 1, as can be seen from Fig. 1. In this configuration, airborne particles drawn through suction inlet 2 is electrostatically charged by electrostatic dust collecting unit 10 and then captured by pre-filter 11.

[0029] Electrostatic dust collecting unit 10 includes needle-shaped discharge electrodes 12 to which a high voltage is applied, earth electrode 13, outer frame 14 for protecting discharge electrodes 12 and earth electrode 13, and a high voltage transformer (not shown) for transmitting a high voltage to needle-shaped discharge electrodes 12.

[0030] If a high voltage of several kilo volts boosted by the high voltage transformer is applied to needle-shaped discharge electrodes 12, a corona discharge is generated between needle-shaped discharge electrodes 12 and earth electrode 13, and electrostatic field 15 is formed in a direction pointed by the tip of needle-shaped discharge electrodes 12.

[0031] Arranging dust collecting unit 10 so that electrostatic field 15 is formed toward suction inlet 2 of indoor unit 1 allows efficient charging of airborne dust particles drawn through suction inlet 2. Thus charged dust particles are attracted by a coulombic force or attractive force toward pre-filter 11 and captured therein.

[0032] Further, the voltage applied to needle-shaped discharge electrodes 12 can be negative or positive.

[0033] In accordance with the first preferred embodiment as described above, since the entire air drawn into suction inlet 2 of indoor unit 1 of the air conditioner is directed into air flow path 7 after passing through the electrostatic field 15 generated by electrostatic dust collecting unit 10, charged airborne dust particles are captured efficiently by pre-filter 11. This configuration allows for a highly efficient air purification function to be added to the air conditioning system. This means cleaner and fresher air to breathe, providing a healthier indoor environment ultimately.

(Second preferred embodiment)

[0034] Below, a second preferred embodiment will be described.

[0035] Referring to Fig. 3, there is provided a schematic vertical cross sectional view of indoor unit 1 of an air conditioner including electrostatic dust collecting unit 20 in accordance with the second embodiment of the present invention.

[0036] Here, parts identical to those described in the first embodiment will be assigned like reference numerals, and their discussions will be omitted.

[0037] In Fig. 3, electrostatic dust collecting unit 20 is installed near air discharge opening 6 of indoor unit 1 of the air conditioner. In accordance with this arrangement, oxygen or free moisture in the air drawn into indoor unit 1 is electrostatically charged as the air exhausted back to the indoor space through air discharge opening 6 passes through electrostatic field 15 of electrostatic dust collecting unit 20. Electrostatically charged oxygen or moisture exhausted back to the indoor space interacts with airborne pollutants in the indoor space. Ultimately, electrostatically charged indoor pollutants are circulated back into suction inlet 2 of indoor unit 1 and captured by pre-filter 11.

[0038] In accordance with the second embodiment as described above, airborne dust particles in the indoor space are electrostatically charged and captured in pre-filter 11 of indoor unit 1 of the air conditioner. As a result, the overall dust collecting operation can be preformed in a bigger volume and airborne bacteria, mold spores and viruses can be reduced even further.

(Third preferred embodiment)

[0039] Hereinafter, a third preferred embodiment of the present invention will be described with reference to Fig. 4.

[0040] Fig. 4 is a schematic external view of pre-filter 11 in accordance with the third embodiment of the present invention.

[0041] In Fig. 4, reference numeral 30 represents conductive resin fiber. Further, parts identical to those described in the first and/or the second preferred embodiment will be assigned like reference numerals, and their discussions will be omitted.

[0042] Commonly used as a conventional pre-filter is a type fabricated by meshing PP or PET resin fibers of about 200 microns and framing the fibers with a resin. However, pre-filter 11 in accordance with the present invention uses PET fibers having a thickness range of 70 to 80 microns. Accordingly, the overall fiber density of the filter is increased while the total open area is maintained without increasing pressure drop across the filter medium compared to a conventionally constructed filter. Finally, pre-filter 11 is constructed with conductive resin fiber 30 at a predetermined interval of, e.g., 5 mm, so that the filter medium can have a conductivity.

[0043] Further, by disposing thus configured pre-filter 11 downstream of dust collecting unit 10 along air flow path 7, a potential difference is produced between pre-filter 11 and dust particles and the like charged by electrostatic dust collecting unit 10. As a result, an attractive force like coulombic force increases, which in turn enhances the system's dust collecting efficiency.

[0044] Moreover, although conductive resin fiber 30 is interwoven with a conventional filter at a predetermined interval in accordance with the third embodiment of the present invention, it is also possible to fabricate a filter entirely with conductive resin fiber 30 or otherwise conductive resin fiber 30 may be woven at a random interval.

(Fourth preferred embodiment)

[0045] Hereinafter, a fourth preferred embodiment will be described with reference to Fig. 5.

[0046] Fig. 5 is a schematic external view of pre-filter 11 in accordance with the fourth embodiment of the present invention.

[0047] In Fig. 5, reference numeral 31 represents an earth connection portion to be connected to a main body of the air conditioner.

[0048] Earth connection portion 31 coupled to conductive resin fiber 30 is connectable to, for example, heat exchanger 4 located in indoor unit 1 of an air conditioner.

[0049] Heat exchanger 4 is entirely formed of metal such as aluminum or copper pipe and, in general, is grounded to the main body of the air conditioner. Thus, by connecting earth connection portion 31 to heat exchanger 4, earth connection portion 31 can be connected to the main body of the air conditioner.

[0050] As described above, since the connection of pre-filter 11 to an earth prepared at the main body of the air conditioner becomes possible by configuring pre-filter 11 to be connectable to heat exchanger 4, a greater potential difference can be generated between dust particles and the like charged by electrostatic dust collecting unit 10 and pre-filter 11. Therefore, an attractive force such as coulombic force is increased, thereby providing an improved dust collecting operation.

[0051] As described above, the air conditioner in accordance with the present invention provides a highly efficient dust collection capacity. Therefore, the present invention can be also incorporated to various apparatuses for eliminating airborne pollutants and allergens like an air purifier or a cleaner.

[0052] While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

1. An air conditioner comprising:

an air filter disposed on a suction side of an air flow path;

an electrostatic dust collecting unit; and

an electrostatic charge portion disposed in the electrostatic dust collecting unit, including an earth electrode, a needle-shaped discharge electrode to which a high voltage is applied, and an outer frame for protecting the needle-shaped discharge electrode and the earth electrode,

wherein the electrostatic dust collecting unit is installed upstream of the air filter, and a discharge area of the electrostatic dust collecting unit is formed upstream of the air filter.

2. An air conditioner comprising:

an air filter disposed on a suction side of an air flow path;

an electrostatic dust collecting unit; and

an electrostatic charge portion disposed in the electrostatic dust collecting unit, including an earth electrode, a needle-shaped discharge electrode to which a high voltage is applied, and an outer frame for protecting the needle-shaped discharge electrode and the earth electrode,

wherein the electrostatic dust collecting unit is installed near an air discharge opening in the air flow path, and a discharge area of the electrostatic dust collecting unit is formed approximate on the front side of the air discharge opening.

3. The air conditioner of claim 1 or 2, wherein at least a part of the air filter has a conductivity.

4. The air conditioner of claim 1 or 2, wherein at least the air filter has a conductive portion in the part and the conductive portion is connected to an earth of a main body of the air conditioner.

Drawing