FI56776C - ELEKTROSTATISK STOFTAVSKILJARE - Google Patents

Description

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Ma ^ * * UTLÄGGN I NGSSKRIFT 567 7 6 C (45fatcr.Ui aydnn ·. Lly 10 -4 1030 i Patent meddolut v (51) Kv.lk. '/ Int.CI.1 B 03 c 3/16 ENGLISH-Fi NLAND (21) Patent application - Patentansökning 7 71T 5 7 (22) Hakemispilvi - Ansöknlnjsdag 02.06.77 ^ (23) Alkupllvi - Giltighetsdag 02.06.77 (41) Has become public - Blivit offentlig Q2.] _2.78

National Board of Patents and Registration .... .. .... . , '(44) Nlhtivikslpanon and kuLLulkalsun p »m. -

Patent and registration authorities Ansökan utlagd och utl. $ Kriften publicerad 31.12.79 (32) (33) (31) Privilege requested — Begird prloritet (71) Arvi Artama, Laukontori h C 30, 33200 Tampere 20, Suomi-Finland (FI) (72) Arvi. Artama, Tampere, Uuno Nurmi, Helsinki, Finland-Finland (FI) (7M Tampere Patent Office (5I +) Electrostatic dust collector - Elektrostatisk stoftavskiljare

The invention relates to an electrostatic precipitator of a type as further defined in the preamble of claim 1.

Electrostatic precipitators are used to remove airborne contaminants, to purify and separate gases, and to remove particulate matter from gases. The medium to be cleaned, e.g., air, is caused to flow between the discharge electrodes and the collector plates, the former being arranged to produce a corona discharge and the electrostatic field of the latter when a sufficiently high voltage is applied to them.

Both dry and so-called wet electrostatic precipitators are known, in which case water jets are arranged in the latter to flush out the dust accumulated on the collector plates of the separator.

Dry electrostatic precipitators have proven to be quite inefficient and have a poor cleaning effect. In addition, they can be flammable and explosive, as the dust that accumulates in them can ignite under certain conditions, which can easily spread the fire in a dusty environment to a wider extent. B Oi C 3/53 2 S 6 7 7 6 Therefore, they cannot and must not be used in industry, for example. Removing dust that has accumulated in the machine can be very difficult.

The construction of known wet electrostatic precipitators is quite complex and expensive, so they are only suitable for use in large air conditioning and dust separation plants.

The object of the present invention is to provide an efficient and simple electrostatic dust separator which is particularly suitable for room air conditioning and industrial dust separation.

The invention is mainly characterized by what is set forth in the characterizing part of claim 1.

The structure according to the features of the invention makes the dust separator very simple in structure and efficient in operation, as well as reliable and easy to maintain. The amount of energy it needs is also quite small.

An embodiment of the invention is illustrated in more detail in the following description with reference to the accompanying drawings, in which Figure 1 shows the basic principle of operation of a device according to the invention schematically, Figure 2 shows a sectional view of a device according to the invention, mainly schematically, Figure 3 shows a second (positive) electrode seen from the front, on a larger scale, Fig. 4 shows the same from the side, Fig. 5 shows a section AA from Fig. 1 with the negative electrode plate visible, Fig. 6 shows a preferred embodiment of the negative electrode plate in an enlarged fragmentary view.

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The principle of the electrostatic precipitator according to the invention is illustrated in Figure 1, in which A and B are electrodes shown in cross section. A is a plate-like negative electrode and B is a wire-like or rod-like positive electrode. A relatively high voltage of a few kilovolts is connected to the electrodes, creating an electrostatic field between them. After this field! when the particle C is brought in by the air flow, it forms an electrical dipole and begins to move in the direction where the field strength is greatest, i.e. in this case towards the wire B. In the case of the present invention, when the yarn is formed by a jet of water or a thin flow, it carries the particle with it. Thus, in the dust separator of the present invention, no air is ionized to electrically charge the particle to be removed. No electric discharge is generated.

One device according to the invention (Figures 2-6) comprises a body housing 1, which is preferably square or rectangular in cross-section. The frame housing is open at the top 2 and can be equipped with an openable cover for inspection and maintenance. Both ends are also open. An air filter 4 of a structure known per se is arranged in the opening of the second end part 3, and a fan 6 is arranged inside the second end part 5, which provides a flow of air through the dust separator. The openings may, of course, be provided with suitable grilles or grilles which do not impede the flow of air but which protect the internal parts and are openable to allow maintenance. The frame housing is preferably made of a suitable plastic material, which simplifies electrical insulation issues. At the bottom of the body there is a liquid basin 7 and under the bottom legs 8.

According to the invention, negative and positive electrodes 10 and 11 are arranged alternately in the central space 9 in the body housing. The positive electrodes 10 (Figures 3 and 4) comprise a frame 12 with a liquid trough 13 or the like at the top. Adjacent, small flow openings 14 are made in the bottom of the trough 13 and thin wires 15 are drawn through the openings, which are attached at their upper end to the rod 16 in the middle of the trough and at their lower end to the lower part of the frame 12. The purpose of the wires 15 is 4 56776 to act as a fluid flow guide. Water or some other liquid runs along the wires. The oil is good in that it is easier to insulate. In this case, the guide wire must be a conductor, for example metal. There is an overflow tube .17 in the middle of the electrode frame, which prevents the chute from overfilling. The troughs of the different electrodes are still connected to each other by a connecting pipe .18, whereby the liquid comes to the same height in all troughs. The inner surface of the body of the device may be provided with guides into which the electrodes are inserted so that they are in the correct position. The spacers 19 separate and support the electrodes. However, the electrodes are electrically connected to each other, e.g. by means of a connecting tube 18, which may be electrically conductive. At their lower end, the electrodes 10 extend below the liquid surface in the liquid basin 7. The device is provided with a pump 20 which, while the device is running, pumps liquid from the basin 7 to the troughs 13, from which it further flows continuously down to the wires 15. A filter 21 is placed on the bottom of the basin, the purpose of which is to collect the contaminants that have entered the basin liquid. The filter is, of course, of the replaceable or cleanable type.

The negative electrodes 11, on the other hand, are similar in structure to a metal mesh plate (Figures 5 and 6) or a fine-mesh cell plate, allowing air flow to pass through them. The plates 11 can also be intact, non-perforated plates if the air flow is parallel to them.

The plates 11 may be coated with an electrically insulating material to prevent electric discharge between the electrodes. They are also most preferably arranged in guides formed in the walls of the housing, with stops such that they do not extend to the liquid surface of the basin 7. The pool is provided with transverse partitions at these electrodes, which, however, do not divide the pool into completely separate compartments.

For the operation of the device, the terminals 22 of a voltage source of more than 4 kV are connected to the electrodes and the pump and fan are started.

As the electrodes become energized and the virtus of the air to be cleaned passes through the device, the different electrical charges of the small dust and other particles in the air separate and the particles generate electrical dipoles, as already mentioned above. In this case, the particles are transported to the wire electrodes formed by the liquid flow, whereby the liquid flow takes them away and the air is efficiently cleaned.

5 567/6 The poles of the voltage source can be reversed, even another electrode, eg the liquid flow, is grounded. The direction of travel of the particles in the field nevertheless remains the same, i.e. towards the wire-like electrode.

Ordinary tap water is suitable for use in the appliance because there are always so many salts in the tap water that they are enough to make the water conductive enough. Other liquids can, of course, be used. If the flowing liquid is an insulating material, the guide wire must be an electrically conductive material.

It is natural that the shape and construction of the device may vary in various ways within the scope of the invention.

Claims (8)

6 S6776 Claims; 1 «A wet-type electrostatic precipitator in which the flow of gas to be cleaned is passed past pairs of live electrodes, one pole of the voltage source being connected to the other and the other to the other electrode, so that an electrostatic field is generated, the electrodes being arranged in succession and next to each other, that a plurality of successive and adjacent electrostatic fields are formed, with one electrode (10) being wire-like (15) and the other (li) substantially plate-like to make the electrostatic fields inhomogeneous, while the applied voltage is adjusted so that no corona discharge occurs but said electrostatic the field causes the different charges of the particles to be separated from the medium to separate from each other and the particles to form electrodipoles and to move in the direction of the electrode with the higher field strength, i.e. towards the wire, characterized in that the liquid used in the separator said wire-like electrodes (15) are flushed to remove any dust particles hitting them. Dust separator according to Claim 1, characterized in that the electrode (10) has a plurality of wires (15) arranged side by side in the frame (12). Dust separator according to Claims 1 and 2, characterized in that the upper part of the electrode frame (12) has a liquid trough (13) or the like, through which holes (14) the wires (15) pass into the lower part of the frame and through which the liquid flows. Dust separator according to Claims 1 to 3, characterized in that the electrodes are arranged in a body housing (1) with air flow openings (3, 5) at the ends and a liquid-all as (7) at the bottom, the pump (20) being adapted to circulate the gutters (13) and through the wires (15). 567/6 Dust separator according to Claim 4, characterized in that a filter (21) is arranged in connection with the basin (7) for cleaning the liquid. Dust separator according to Claim 4, characterized in that the gutters (13) have an overflow pipe (17). Dust separator according to Claim 4, characterized in that there is a connecting pipe (IS) between the different troughs (13). Dust separator according to Claim 4, characterized in that a filter (4) and a fan (6) are arranged in the second end opening (3) of the housing (1). Dust separator according to Claims 1 to 8, characterized in that the plate-like electrodes (II) are either air-permeable mesh plates or perforated metal plates and can be covered with an electrically insulating substance to prevent electrical discharges. 8 56776