US3626669A - Electrostatic air filtering means - Google Patents

Abstract

AN ELECTROSTATIC AIR FILTERING UNIT IS ADAPTED TO BE USED IN AN AIR FILTER. THE MODULAR STRUCTURAL CELL HAS AN OUTER PRE-FILTER PANEL, AN INNER PARTICLE COLLECTOR AREA AND AN IONIZER AREA THEREBETWEEN. ALTERNATELY CHARGEABLE AND GROUNDABLE PLATE MEMBERS IN THE PARTICLE COLLECTOR AREA FORM PASSAGEWAYS FOR AIR TO BE FILTERED, AND COLLECT CHARGED PARTICLES IN THE AIR DURING OPERATION. CHARGEABLE FILAMENTS ARE IN THE IONIZER AREA, AND DURING OPERATION CHARGE THE PARTICLES TO BE REMOVED FROM THE AIR AS THEY PASS THROUGH THE IONIZER AREA. THE PRE-FILTER PANEL IS EASILY REMOVABLY MOUNTED IN AN ENCLOSURE AROUNG THE IONIZER AREA, AND HELD IN MOUNTED POSITION BY RESILIENT MEANS WITH THE ENCLOSURE AND MOUNTING PERMITTING THE PANEL TO BE REMOVED FOR MAINTAINING THE MODULAR CELL.

Description

DeC- 14, 1971 G. H. CARDIFF 3,626,669

ELECTROSTATIC AIR FILTERING MEANS Filed Nov. 5, 1969 5 Sheets-'Sheet 1 INVIN'IUR.

GEORGE H. CARDIFF ATTORNEY Dec. 14, 1971 G. H. CARDIFF 3,625,659

ELEoTRosTATIc AIR FILTERING MEANS Filed Nov. vs. 1969 5 sheets-sheet a INVIN'VUR.

GEORGE H. CARDIFF ATTORNEY G. H. cAnDlFF 3,626,669

Dec. 14, 1971 ELECTROSTATIC AIR FILTERING MEANS 5 Sheets-Sheet 3 Filed NOV. 5, 1969 INVENTOR.

GEORGE H. CARDIFF ATTORNEY D 14, 1971 G. H. CARDIFF' ELECTROSTATIC AIR FILTERING MEANS 5 Sheets-Sheet 4 Filed NOV. 5. 1969 INVEN'V( )R.

GEORGE H. CARDIFF ATTORNEY Dec. 14, 1971 G. H. cARDu-'F `352511559 ELEGTROSTATIC AIR FILTERING MEANS Filed Nov. 5, 1969 5 Sheets-Sheet 5 O o O GEORGE H. CARDIFF ATTORNEY United States Patent O Int. Cl. B03c 3/01 U.S. Cl. 55-126 3 Claims ABSTRACT OF THE DISCLOSURE An electrostatic air filtering unit is adapted to be used in an air filter. The modular structural cell has an outer pre-filter panel, an inner particle collector area and an ionizer area therebetween. Alternately chargeable and groundable plate members in the particle collector area form passageways for air to be filtered, and collect charged particles in the air during operation. Chargeable laments are in the ionizer area, and during operation charge the particles to be removed from the air as they pass through the ionizer area. The pre-filter panel is easily removably mounted in an enclosure around the ionizer area, and held in mounted position by resilient means with the enclosure and mounting permitting the panel to be removed for maintaining the modular cell.

This is a continuation-in-part of my application Ser. No. 825,732 led May 19, 1969, entitled Improved Electronic Air Filter Means.

In operation the pre-filter panel, a screen like passageway, removes large objects from the air, the ionizer area, having electrically charged filaments, gives the particles in the air an electrical charge and the particle collector area, a series of parallel plates electrically charged, removes the charged partices from the air. Furthermore, the modular nature of this invention allows removal from the electronic air filtering means as a unit and can be partially disassembled for cleaning and maintenance lwith the minimum amount of time and effort by removal of the resiliently retained pre-filter panel.

Numerous types of electrostatic air filtering means are known to the prior art as precipitator units for electronic air filtering means. The prior art devices are generally limited in filtering capacity and compactness, and not readily operable for high flow rates to filter out smoke, tar, nicotine, dust particles and the like. Also the prior art devices are either not removable from the structure, or if they are removable are multi-modular in their structure, thus difficult to clean and cumbersome to handle. Therefore, it is desirable to provide a structure which is removable from the electronic air filter and easily cleaned as well as efficient in its function of cleaning the air.

In preferred specific embodiments of this invention, an improved electrostatic air filter means is provided including an electrostatic cell like structure filtering means for use in ceiling mounted electronic air filtering means, or where the cells do not operate immediately adjacent one another; and an embodiment having a cell structure for use in electronic air filtering means where the cells operate immediately adjacent one another, as in duct and wall mounted air filter structures.

The ceiling mounted electronic air filtering means or a like apparatus where the electrostatic precipitator cells are not immediately adjacent, generally include a box like structure with openings on several sides for admission of air. The electrostatic precipitators being located within the structure behind the openings makes it unnecessary for physical contact with the adjacent cell for its electrical power. The electrostatic filtering means includes a pre-filter panel, an ionizer area, and particle collector 3,626,669 Patented Dec. 14, 1971 combined in one cell like structure. The pre-filter panel means includes a small mesh screen and attaching frame which is held in the outer face of the structural cell by a retaining clip and resilient means. The pre-filter can thus be removed easily from the electrostatic precipitator cell for cleaning and maintenance of the unit. The ionizer area is immediately adjacent the pre-filter panel and has a plurality of generally parallel tungsten wire members eX- tending across the area which in operation impart to the particles within the air flow a positive electrical charge as they move nearby. The particle collector area follows flowwise the ionizer area, and includes a plurality of alternately charged and grounded plate members oriented tO align stream wise with and transversely across the air flow. Electrical power is supplied the electrostatic precipitator by means of spring loaded contacts touching a particle collector plate. The plates are interconnected thus spreading the electrical charge, also the ionizer filaments are charged by their attachment to the charged collector plates. In the electronic air filtering means the electrostatic precipitator structure precedes an after-filter agglomeration assembly which functions to retain any particles which may be disengaged from the particle collector while in operation.

A new and novel feature of this invention is that by placing the pre-filter, ionizer and particle collector in one unit it can be removed from the electronic air filtering means as an entity and easily opened for inspection, cleaning, and maintenance thereof, and the unit is made easy for such by the finger pressure removable mounting of the outer screen which normally collects only larger particles and trash from the air.

In another preferred specific embodiment of this invention for use with duct and wall mounted electronic air filter structures employing a plurality of electrostatic precipitators in a unit and located adjacent one another, the cell structure is similar in type except for the method of transferring electrical power. Electrical power is transferred to the chargeable plates by contacts in the electronic air filter structure touching leaf spring contacts engaged with the supporting means of the chargeable plates in the particle collector. The leaf springs are located on opposite ends of the particle collector structure, thus passing the electrical power into and through the plates of the particle collector. The novel and new features of this embodiment are similar to those of the first embodiment.

One object of this invention is to provide a new and novel electrostatic air filter means overcoming the aforementioned disadvantages of the prior art devices.

Another object of this invention is to provide a modular electrostatic air filtering means which is easily adaptable to previous electronic air filter structures and with at least the efficiency of prior art devices, and easier to inspect, clean and maintain.

A further object of this invention is to provide such an electrostatic air filtering means which is easy to inspect, maintain and clean.

Still another object of this invention is to provide an electrostatic air filter means which has a minimum of parts, is compact in size, and economical to manufacture.

Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded fragmentary perspective view of a preferred specific embodiment of this invention;

FIG. 2 is a side elevation view of the preferred specific embodiment of FIG. 1 partly cut away;

FIG. 3 is a frontal elevation view of the invention partly cut away;

FIG. 4 is a schematic diagram of the electrical circuit of the preferred specific embodiment shown in FIG. l;

FIG. 5 is an enlarged cut out perspective view of the entryway with the pre-filter panel partly removed;

FIG. 6 is an enlarged cut out perspective view of the entryway showing the pre-lter panel partially slid away exposing the ionizer area;

FIG. 7 is a sectional view taken on line 7 7 of FIG. 6;

FIG. 8 is a perspective view of a duct mount type preferred specific embodiment of this invention with the control means cover removed;

FIG. 9 is a schematic diagram of the electrical circuit for the duct mount type preferred specific embodiment of this invention;

FIG. l is an exploded perspective view of the duct mount type preferred specific embodiment of this invention;

FIG. ll is an exploded perspective view of the compact duct mount type preferred specific embodiment of this invention;

FIG. 12 is a sectional view taken on the line 12--12 of FIG. 1l;

FIG. 13 is an exploded perspective view of the wall mounted type preferred specific embodiment of this invention;

FIG. 14 is a front elevation vieW of the invention partly cut away exposing the pre-filter support frame, ionizer area and particle collector;

FIG. l is a cut out perspective view of the invention partly cut away;

FIG. 16 is a partial sectional View taken on line 16-16 of FIG. 14; and

FIG. 17 is a schematic diagram of the electrical circuit of the wall mount type preferred specific embodiment of this invention.

The following is a discussion and description of preferred specific embodiments of the electrostatic air filtering means of this invention such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/ or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.

The improved electrostatic air filter means of this invention is specifically disclosed herein in two preferred primary embodiments, namely one intended preferably for use in ceiling mounted type electronic air filtering means as where the electrostatic air filtering cells operate collectively but not immediately adjacent; and in a second embodiment, namely where the electrostatic air filtering cells operate adjacent and collectively, preferably in duct and wall mount type electronic air filtering means as 12, or the duct mount type electronic air filter means 14. As shown generally in FIGS. l and 2, the first named embodiment of this invention is for use in ceiling electronic air filtering means 10, which in operation receives air through openings near the ceiling 14 on which it is mounted, and fan 18 pulls the air through the electrostatic air filtering means 20, the after-filter 22 and discharges it through the opening 24. The types of electronic air filtering means preferably using the second embodiment of this invention are shown generally in FIGS. 8, 10, 11, and 13; these are preferably intended to mount in line with the air return ducts of a Ventilating system and adjacent to the heating/cooling unit.

The electrostatic air ltering means of both embodiments is generally similar, having pre-filter panel 26, ionizer area 28 and particle collector 30. The pre-filter panel 26 is a generally rectangular section of fine mesh screen 32 surrounded by a frame 34 for structural support, which is retained in the front of the entryway 35 by clips 36 on opposite sides of the entryway 35, which are integrally formed therewith, and a resilient means 38 which causes the pre-filter frame 34 to be held firmly against one side of the entryway 35 by pressure from the resilient member 38 on the other side. The pre-filter panel 26 when in place is within the clips 36 on either side of the entryway 35, and is removed by compression of the resilient member 38 by finger pressure pushing the prefilter panel toward the resilient member 38, so the frame 34 of the pre-filter panel 26 can be removed from the clip 36 on the opposite side of the entryway 35. The pre-filter panel 26 is easily inserted by compressing the resilient means 38 with finger pressure sufficient to allow the frame 34 of the pre-filter panel to slip into the clip member 36. With the pre-filter panel 26 removed the ionizer area 28 is visible in the entryway 35. The ionizer area 28 contains a plurality of parallel tungsten wires 40 which operate to charge the particles in the air. The wires 40 are suspended from support members 42 which are attached to the alternate chargeable plate members 44 of the particle collector 30, in a fashion to be generally in line with the adjacent groundable plate. The particle collector 30 comprises a plurality of generally parallel plate members consisting of chargeable plate members 44 and groundable plate members 46, which are alternated in position spacing, separated and insulated by the rod like attaching means 48 supporting the corners of the groundable plate members 46 and the chargeable plate members 44, and similarly attached by an insulating means 50 and a rod like attaching means 48. The outer groundable plate member 52 has a raised outer member 54 that provides structural support for the electrostatic air filtering means when in place within the electronic air filtering means. The outer groundable plate member 52 contains a hole 56 allowing access to the nearest chargeable plate member 44 for the electrical contact 58.

The preferred ceiling filter type embodiment of this invention uses the hole 56 in the outer groundable member 52 as the principle means of obtaining electrical power.

A second preferred specic embodiment of this invention obtains electrical power as the first embodiment, but preferably electrical power is transmitted to the chargeable plate members 44 through leaf spring contacts 60 engaged in the attaching and connecting means 48 of the members. The leaf springs 60 touch contacts 62 in the housing of the electronic air filtering means which transfer electrical power to the means from the power supply 64 as indicated generally in the schematic diagrams, FIGS. 4, 9 and 17, of the control means 66 for the electronic air filtering means.

In use and operation, the electronic air filtering means is similar regardless of the particular embodiment. Upon energizing the system with the control means 66, a low amperage high voltage D.C. energy source is supplied the electrostatic precipitator. Particle laden air flowing through the electronic air filtering means first enters the pre-filter 26; the large particles are retained in the prefilter 26 and the remainder pass into the ionizer area 28 and receive an electrical charge from the filament wires of the ionizer area 28, and pass on to the particle c01- lector 30 in which the charged particles are repelled from the similarly charged plates and are attracted to the oppositely charged or grounded plates, thereby removing the particles from the air and collecting them. Upon leaving the particle collector 30, the air passes through the after-filter 22, which collects any particles that become detached from the plates of the particle collector 30, then the air returns to the Ventilating systems. After the system has been in operation for a period of time the plates of the particle collector 30 become covered with particles such as oil, resins, nicotines, tars and the like which must be removed. Upon removing the access panels from the electronic air filtering means, the electrostatic air filtering means 20 is removable from the system, and the afterfilter can also be removed. Cleaning of the electrostatic air filtering means 20 is easily done in a conventional dishwasher, or cleansed in a like manner. Obviously the electrostatic air filtering means 20 can be cleaned as a.

unit or the pre-filter panel 26 can be removed and the two parts cleaned separately and inspected for any necessary maintenance simultaneously.

It is seen the electrostatic air filtering means of this invention provides a very compact modular structure which is easily adaptable to existing electronic air filtering means, highly efiicient air ltering use, greatly simplified in design and construction, lending itself to economical manufacture and easy maintenance and cleaning thus makig the unit ideal for home and small business use.

It will be apparent from the foregoing description of preferred specific embodiments of the improved electrostatic air filtering means that it provides, a simple, compact, and efficient electrostatic air filtering means. The device has the advantage of being a modular unit and constructed to be easily cleaned as a unit thus avoiding time consuming service work.

While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that the description is intended to illustrate the invention defined by the following claims.

I claim:

1. An electrostatic air filtering means adapted to be used in an electronic air filtering means, comprising:

(a) a structural cell combining an outer pre-filter panel, an inner particle collector area, and an ionizer area therebetween,

(b) said structural cell having an enclosure around said ionizer area defining an entryway of size substantially the same as said pre-filter, containing said pre-filter panel and ionizer area, thereby in operation directing the air to be filtered through said pre-filter and ionizer area and into said particle collector area,

(c) said pre-filter being mesh screen and having edge supporting frame means and preceding in operational flow a particle collector and precipitator mounted in said particle collector area and having spaced substantially parallel plate members alternately chargeable and groundable defining passageway Zones, and extending substantially transversely across said entryway to provide said passageway zones, and means to charge and ground said plates,

(d) a plurality of chargeable filament members in said ionizer area frnounted on said chargeable plates and extended substantially parallel thereto and means to connect said filament member to a source of electricity.

(e) said pre-filter panel and said enclosure around said ionizer area having means to resiliently maintain said panel in operation position with said panel being easily removable rfor cleaning and maintenance of said electrostatic air filtering means by finger pressure releasing same from said enclosure against the force resiliently maintaining said panel in position,

(f) said pre-filter panel placed within said entryway is constructed to be placed generally perpendicular to the operationally entering air fiow,

(g) said pre-filter panel is held at said entryway by means of clips integrally formed in the entryway and a resilient forcing member to retain said panel in proper operational perspective within said clips,

(h) said resilient forcing member is located within said clip and compression of it allows said panel to be easily removed from said clip on the opposite side of said entryway,

(i) said particle collector area has said groundable plates alternating in placement order with said chargeable plates and such that said groundable plates are on the extremities thereof,

(j) said plate members of said particle collecting area are uniformly connected to like members in a layer type arrangement by a series of rod members passing through holes in said plate members and substantially evenly separated by a series of sleeve members placed on said rods and between said like plates,

(k) said chargeable plates and attached ionizer filaments of said precipitator obtain electrical power through contact with a spring loaded contact located within said electronic air filtering means when installed therein such that said electrostatic air filtering means operate nonadjacently,

(l) said spring loaded contact touches said charged plate by entering the structure through a hole in the outermost one of said groundable plates and contacts the adjacent one of said chargeable plates,

(m) `said chargeable plates of the particle collector obtain electrical power through leaf spring contacts engaged with said chargeable plates, and

(n) said leaf spring contacts provide electrical continuity between adjacent cells when a plurality of said cells are used in an electronic air filtering means.

2. An electrostatic air filtering means as described in claim 1, wherein:

(a) said filament members secured to said chargeable plates through support clip members to position said filament members centrally of adjacent one of said chargeable plates, and

(b) said structural cell removable as a complete, compact single unit with all of the charged and filter panels for repair and maintenance.

3. An electrostatic air filtering means as described in claim 2, wherein:

(a) said outer groundable plate member having a raised outer member to provide a restriction and support for said pre-filter panel when in the assembled condition, and

(b) said groundable plate members and said chargeable plates separated by an insulating means and rodlike attaching means.

References Cited UNITED STATES PATENTS 1,984,135 12/1934 Houston 55-509 X 2,486,520 11/1949 nahimari 55-126 2,521,605 9/1950 Richardson 55-143 3,016,980 1/1962 Gonzalez 55-146 X FOREIGN PATENTS 789,360 1/1958 Groar Britain 55-143 DENNIS E. TALBERT, JR., Primary Examiner U.S. Cl. X.R.

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