JPH09173892A - Dielectric type air filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent that a filtering pore size becomes excessively fine by the collapse of the filter material of a dielectric type filter caused by wind pressure to fasten clogging. SOLUTION: A thin upper layer filter material 3 having charge properties, a rough and stiff middle layer filter material 4 low in charge properties and a lower layer filter material 5 having charge properties and denser than the middle layer filter material 4 are laminated to be held between the metal net- like electrodes 1, 2 of a dielectric type air filter. When the filter materials are charged to allow air to flow, the dust bonded to the upper layer filter material 3 is flocculated to become large and blown off to be caught by the middle filter material 4 and the remaining dust is caught by the lower layer filter material 5. The middle layer filter material 4 is a coarse filter material and, since the bonded dust is made large, the clogging of the filtering pore size of the lower layer filter material 5 is reduced. Since the respective layers act on the catching of dust equally, the local clogging of a specific layer is not generated and clogging life is extended as a whole.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】この発明は家庭用や業務用に
用いられる空気清浄器の誘電式エアフィルタに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric air filter for an air purifier used in homes and businesses.

【０００２】[0002]

【従来の技術】誘電式エアフィルタは通常の機械的濾過
によるエアフィルタに比べてダストの捕捉効率が高く、
特に微細粒子例えば花粉や煙草の煙等に対して捕捉作用
が大であるから、室内用のエアフィルタ等に用いられて
いる。この誘電式エアフィルタは、一対の電極間の放電
を防止するため、電源の種類（高電圧の容量）にもよる
が通常５〜２０ｍｍ程度の間隔を保つようにしている。2. Description of the Related Art Dielectric air filters have a higher dust trapping efficiency than air filters using ordinary mechanical filtration.
In particular, since it has a great trapping effect on fine particles such as pollen and cigarette smoke, it is used for indoor air filters and the like. In order to prevent discharge between the pair of electrodes, this dielectric air filter is normally kept at a distance of about 5 to 20 mm depending on the type of power source (capacity of high voltage).

【０００３】従って電極の間に挟まれる濾材は、帯電し
やすい繊維でなり、通常５〜２０ｍｍ程度の厚さを有す
るものとなる。このような濾材で目詰まり寿命やダスト
の捕捉効率や圧力損失（流体抵抗）を考え合わせると、
濾材は繊維径を細くし、従って腰の弱い（柔軟性の大き
い）ものとなる。Therefore, the filter material sandwiched between the electrodes is a fiber which is easily charged with electricity, and usually has a thickness of about 5 to 20 mm. Considering clogging life, dust capture efficiency and pressure loss (fluid resistance) with such filter media,
The filter medium has a small fiber diameter, and thus has a low stiffness (high flexibility).

【０００４】[0004]

【発明が解決しようとする課題】このような濾材では、
ダストの付着がそのまま圧力損失の増大となり、目詰ま
り寿命の延長がはかり難い。またダスト付着の進行に伴
ない表面のダストにより濾材にかかる風圧が大となり炉
材が潰れて密度が上がり（濾孔径が細かくなり）濾材の
厚さが有効に利用されず、結果的に目詰まり寿命が短か
くなっていた。SUMMARY OF THE INVENTION In such a filter medium,
The adhesion of dust increases the pressure loss as it is, and it is difficult to extend the life due to clogging. In addition, as the dust adheres to the surface, the dust on the surface increases the wind pressure applied to the filter material, crushing the furnace material and increasing the density (filter pore size becomes finer), and the thickness of the filter material is not effectively used, resulting in clogging. Life was getting shorter.

【０００５】[0005]

【課題を解決するための手段】この発明の誘電式エアフ
ィルタは電極間に挟む濾材を３層で構成し、上層濾材は
帯電性のある薄い濾材でなり、中層濾材は帯電性が低
く、粗くて腰のある濾材でなり、下層濾材は帯電性のあ
る濾材（従来の誘電式エアフィルタの濾材と同質のも
の）でなるものである。The dielectric type air filter of the present invention comprises three layers of filter medium sandwiched between electrodes, the upper layer filter medium is a thin filter medium having an electrostatic property, and the intermediate layer filter medium has a low electrostatic property and is rough. The lower filter medium is a filter medium having electrostatic properties (the same quality as that of conventional dielectric air filters).

【０００６】このように濾材を３層で構成して、電圧を
印加すると全体が帯電されるが、上層濾材がプレフィル
タとして作用し、吸い込まれて進入して来たダストが付
着し帯電する。このダストの付着が進行するとダスト同
士が凝集して粒子が大型化し、さらに付着量が増えると
抵抗が増し、濾材層が薄いので通過する風量の変化によ
って吹き飛ばされ、上層濾材を吹き抜け、一部が中層濾
材に捕捉される。中層濾材に捕捉されず吹き抜けたダス
トは下層濾材に到達し捕捉される。下層濾材は中層濾材
より密であるが、捕捉したダストは凝集して大型化した
粒子であるから、目詰まりが起き難い。この場合中層濾
材は帯電性が低いのでダストの捕捉が一部に止まり、大
型化粒子を大量に捕捉して目詰まりを早めることがな
い。なお実験的にも中層濾材は下層濾材より帯電性が少
ないほうが全体としてダスト捕捉効率が良く、目詰まり
寿命が長くなることが確かめられている。このようにダ
スト荷電用の薄いプレフィルタを用い、中層と下層とに
帯電性の強度勾配を持たせることにより、ダスト捕捉が
厚さ方向に均等化され目詰まり寿命が延びる。As described above, the filter medium is composed of three layers and the whole is charged when a voltage is applied, but the upper filter medium acts as a pre-filter, and the dust that has been sucked in and invaded is charged and charged. As the adhesion of the dust progresses, the particles agglomerate with each other and the size of the particles increases, and the resistance increases as the amount of adhesion increases, and the filter material layer is thin, so it is blown away by the change in the air volume passing through it, and blows through the upper layer filter material. It is captured by the middle layer filter medium. The dust blown out without being captured by the middle-layer filter medium reaches the lower-layer filter medium and is captured. Although the lower layer filter medium is denser than the middle layer filter medium, clogging is less likely to occur because the captured dust is agglomerated and enlarged particles. In this case, since the middle-layer filter medium has a low chargeability, dust is not trapped in a part, and large-sized particles are not trapped in a large amount to accelerate clogging. It has also been experimentally confirmed that when the middle-layer filter medium has less chargeability than the lower-layer filter medium, the dust capturing efficiency as a whole is better and the clogging life is longer. By thus using a thin pre-filter for charging dust and providing a chargeable strength gradient between the middle layer and the lower layer, dust trapping is made uniform in the thickness direction and clogging life is extended.

【０００７】[0007]

【発明の実施の形態】図１によりこの発明の実施の形態
を説明する。図示の誘電式エアフィルタは室内用の空気
清浄器に組み込まれるもので、金網状の電極１、２を対
向させて設け、電極１、２間に、上層濾材３、中層濾材
４、下層濾材５を積層して挟持し高電圧印加手段７を接
続してなる。電極１、２の（＋）極、（−）極はどちら
にしてもよく、その間隔は５〜２０ｍｍ程度である。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIG. The illustrated dielectric air filter is incorporated in an indoor air purifier, and is provided with wire mesh electrodes 1 and 2 facing each other, and an upper layer filter medium 3, an intermediate layer filter medium 4, and a lower layer filter medium 5 are provided between the electrodes 1 and 2. Are laminated and sandwiched, and the high voltage applying means 7 is connected. Either of the (+) pole and the (-) pole of the electrodes 1 and 2 may be used, and the distance between them is about 5 to 20 mm.

【０００８】上層濾材３は例えば帯電性に富んだポリプ
ロピレン繊維の５〜３０μｍの細い繊維でなり目付量１
０ｇ／ｍ²〜４０ｇ／ｍ²程度で薄く、次の中層濾材４に
比べて比較的密である。上層濾材３はプレフィルタとし
て作用する。The upper filter medium 3 is, for example, a polypropylene fiber having a high chargeability of 5 to 30 .mu.m and a basis weight of 1
0 g / m thin at ² to 40 g / m ² approximately, is relatively dense compared to the next intermediate filter medium 4. The upper filter medium 3 acts as a prefilter.

【０００９】中層濾材４は帯電性の低い例えばポリエス
テルの比較的太径の繊維でなり、濾孔径も粗いものとす
る。繊維が太径であるため腰が強い（柔軟性が低い）濾
材である。The middle layer filter medium 4 is made of a fiber having a relatively large diameter, such as polyester, which has a low charging property, and has a coarse filter pore size. It is a filter medium that is strong (low in flexibility) because the fiber has a large diameter.

【００１０】下層濾材５は上層濾材３と同質のものであ
り目付量１５０ｇ／ｍ²〜４００ｇ／ｍ²の不織布であ
る。また上層濾材３の周縁は延伸部６を有しており、中
層濾材４の側面を包んで下層濾材５の周縁に熱溶着さ
れ、各層濾材を一体化している。[0010] lower layer filter medium 5 is a top filter medium 3 and is of homogeneous basis weight 150g / m ² ~400g / m ² nonwoven fabric. Further, the peripheral edge of the upper layer filter medium 3 has a stretched portion 6, which covers the side surface of the middle layer filter medium 4 and is heat-welded to the peripheral edge of the lower layer filter medium 5 to integrate the respective layer filter mediums.

【００１１】上記の構成において両電極間の間隔例えば
１０ｍｍに対し上層厚さが０．５ｍｍ、中層厚さが７．
５ｍｍ、下層厚さが２ｍｍ程度であり、印加する電圧は
６ＫＶである。このエアフィルタ１は最も厚い中層濾材
３を腰の強いものとしたので風圧によってヘタって潰れ
ることがほとんどなく、潰れによる濾孔径細密化で目詰
まりが急激に進行したり、濾材装着にガタが生じたりす
ることがない。またダストを凝集させて大型化するの
で、同一捕捉量に対しても目詰まり寿命（圧力損失の上
限）が延長される。In the above structure, the upper layer thickness is 0.5 mm and the middle layer thickness is 7.
The thickness is 5 mm, the lower layer thickness is about 2 mm, and the applied voltage is 6 KV. In this air filter 1, since the thickest middle-layer filter medium 3 has a strong rigidity, it is hardly blown out and crushed by wind pressure, and the filter hole diameter becomes fine due to crushing, which causes rapid progress of clogging and looseness in mounting the filter medium. It never happens. Further, since the dust is aggregated to increase the size, the clogging life (upper limit of pressure loss) is extended even for the same trapping amount.

【００１２】[0012]

【発明の効果】この発明のエアフィルタは、濾材を、ダ
ストを大粒化するプレフィルタと、腰が強く粗い中層
と、帯電性の強い下層との３層で構成したので、濾材の
潰れによる目詰まりの進行がなく、また帯電性の強度勾
配によりダスト捕捉が厚さ方向に均等化され、またダス
トは大粒化するので濾孔の閉塞が少なく、目詰まり寿命
が延長される。In the air filter of the present invention, the filter medium is composed of three layers of a pre-filter for increasing the size of dust, a strong and rough middle layer, and a lower layer having a strong electrostatic property. There is no progress of clogging, dust trapping is made uniform in the thickness direction due to the electrostatic strength gradient, and since the dust becomes larger, clogging of the filter holes is less and clogging life is extended.

【図面の簡単な説明】[Brief description of the drawings]

【図１】この発明の実施の形態例を示す図。FIG. 1 is a diagram showing an embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１、２ 電極 ３ 上層濾材 ４ 中層濾材 ５ 下層濾材 1, 2 electrode 3 upper layer filter medium 4 middle layer filter medium 5 lower layer filter medium

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 一対の網状の電極の間に濾材を配置し電
極に高電圧を印加するようにした誘電式エアフィルタに
おいて、濾材を、帯電性のある薄い濾材でなる上層濾材
と、帯電性が低く、粗くて腰の強い中層濾材と、帯電性
のある下層濾材とで構成したことを特徴とする誘電式エ
アフィルタ。1. A dielectric air filter in which a filter medium is arranged between a pair of mesh-shaped electrodes and a high voltage is applied to the electrodes, wherein the filter medium comprises an upper layer filter medium composed of a thin filter medium having electrostatic properties and a chargeability. A dielectric air filter characterized by comprising a low-roughness, coarse and strong middle-layer filter medium, and a chargeable lower-layer filter medium.