DE1757115A1 - Electro-aerodynamic failure device - Google Patents

Description

Dr. Ing. E. BERKENFELD · Dipl.-Ing. H. BERKENFELD, patent attorneys, Cologne Attachment file number

for entry from April 1, 1968 Sch // Name d. Note University of Illinois

Foundation

Electro-aerodynamic precipitation device.

The invention relates to gas separators and more particularly to electrostatic failure devices.

The known electrostatic precipitation devices usually have a group of collector plates, with a charging electrode between each pair of plates and the whole group arranged in the flow of the dust-laden gas is. One side of a high voltage power source with one polarity is connected to the plates and the other Side of the high voltage power source with the opposite polarity with the charging electrodes to move between the charging electrode and the plate concerned on each side of the same to generate an electric field. Since between the charging electrodes and the plates there is usually a high voltage of 10,000 V or If there is more, the panels must be spaced a sufficient distance apart from the charging electrode to avoid the unwanted strike through of the medium between the electrode and the plate to prevent an undesired short circuit of the high-voltage power supply would cause. This distance is also necessary if the panels are cleaned by abrasion

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should. All common electrostatic failure devices therefore contain collector plates that are 150 - 180 mm apart.

For the operation of precipitation devices with plates at such intervals, the designers have to use the one to be used indicated optimal gas flow rate. For example, if the panels are at a distance of 180 mm, the assumed optimal gas flow velocity is approximately J5 m / s. As most electrostatic precipitators to be used in gas flows whose velocities are almost ten times the optimal flow velocity The gas flow must be slowed down before it enters the precipitator.

The known precipitators are therefore because of the space required the panels are quite large and bulky and their performance is significantly less than would be desirable.

Another factor, that of the inefficient mode of operation of the known electrostatic precipitators is the use of an electric field in one direction which is perpendicular to the direction of gas flow. The particles must therefore move out of their original direction of flow Entrance to be deflected in the direction of the charging field before they hit the collector plates.

Further, if the charging wires are between the collector plates, cleaning the plates for removal is required

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of the precipitated particles that the supply of the high voltage current at least for the particular set of those to be cleaned Collector plates is interrupted or switched off. This requires quite complicated switching devices, which automatically switch the kV high voltage supply on and off *

According to the present invention is an electro-aerodynamic Precipitation device provided, in which the electric field between the charging electrode and the collector plates in the Maintain the direction of flow of the incoming dust-laden gas will. According to a feature of the invention, the precipitation device includes a plurality of collector plates, the at a distance of 12.5 mm or less from each other, while the charging electrode is relative to the collector plates is supported in an outer position around which the particles generating charging electric field in a direction that is aligned with the flow of the dust laden gas entering the precipitator.

The use of such a design enables the electro-aerodynamic The precipitation device according to the invention has the following advantages over the known precipitation devices to achieve:

1) a more effective steering and collection of charged particles in the gas flow to the collector plates, because the elec- [trical field is gehalfcn aligned with the direction of the incoming gas flow.

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2.) The use of collector plates that are close together gives more collection units per unit area so performance improves and weight and size are more comparable Failure devices is reduced.

3.) Gas flow rates of more than 3 m / s and up to about 39 m / s can be processed directly without an additional device to slow down the incoming gas flow would be required. This also increases the performance the device improved over the known precipitation devices because a larger amount of dust-laden per unit of time Gas can be processed.

4.) Between the charging electrodes and the collector plates, higher charging voltages can be maintained without to increase the possibility of an undesired short circuit in the supply of the high-voltage current.

5.) If according to the principles of the invention for the charging electrodes If a number of stationary wires are used, these wires can be kept free of accidentally deposited dust particles by aerodynamic fluttering vibrations which are caused by the higher flow rate of the in the precipitator entering gas are generated.

6.) The deposits on the collector plates can be from the same can be easily removed without it being necessary to supply the high voltage during the ReiηigungsVorganges to interrupt electricity.

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7.) In a rotatable precipitation device according to the invention, the use of stationary Äufladedrähten allows are arranged outside the collector plates and cleaned by aerodynamic plate vibrations that the rotating collector plates can be easily cleaned without the supply of the high-voltage current is switched on and off synchronously during the cleaning process.

In summary, it can therefore be noted: The invention relates to an electro-aerodynamic failure device with a set of a first polarity High voltage wire electrodes immediately adjacent on a set of collector plates having the opposite polarity, with the direction of the electrical generated between the electrodes and the plates Field is aligned with the direction of flow of the dust-laden gas entering the precipitator. A rotatable electro-aerodynamic precipitator with collector plates spaced approximately 12.5 mm or less is effective at gas flow velocities greater than 3 m / s.

A preferred embodiment of the precipitation device according to The invention is explained below with reference to the drawings described in which shows:

Pig, 1 shows a partial longitudinal section along line 1-1 of Fig. 2,

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Pig. 2 shows a longitudinal section along the line 2-2 of FIG. 1,

3 shows a schematic representation of the charging wires,

which are arranged outside the collector plates in such a way that an electric field is generated becomes that with the direction of flow of the entering dust-laden gas is aligned.

In Figures 1 and 2 is a rotatable electro-aerodynamic Failure device 10 shown, which has a housing 12 with a Has inlet port 14 and an outlet port 16.

The direction of the incoming flow of the dust laden gases is indicated generally by the arrows 18 which indicate the direction in which the dust laden gases flow Failure device 10 entering through inlet opening 14 Designate gases. After the particles have been precipitated, the gases can be released from the housing 12 through the outlet opening Ί6 step out.

As Fig. 1 shows _; the housing 12 has lower attachment surfaces 20 which are welded to a cleaning liquid return line 22 and a drying air return line 24, so that a completely sealed unit is formed. The dust-laden gases entering the precipitating device 10 through the inlet opening 14 can therefore only exit through the outlet opening 16 after cleaning.

In the path of the dust-laden gases entering there is a ring of charging wires 26 and a plurality of collector plates 28

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orderly. The charging wires 26 are arranged in a ring-like manner within the housing 12 between the side walls 30 and 32 thereof. Corresponding electrical insulating means 34 are provided for fastening the ends of the charging wires to the side walls. to prevent an undesired short circuit between the wires and the side walls.

One end 29 of each of the collector plates 28 is in the radial direction at a distance of 25-100 mm from the charging wires 26 arranged. The collector plates 28 are at a distance of approximately 12.5 nim from each other on the rotary drum> 6. The drum 36 is rigidly attached to a drive shaft 58, those in the housing 12 by means of bearings 40 on the side wall 32 of the housing is rotatably mounted. The free end of the shaft 38 is driven by motor drive means (not shown) to rotate the drum 36.

Any appropriate means can be used to reduce the To hold collector plates 28 in their set position on the rotary drum 36. For example, it can be circular Disc 42 may be provided, the radial width of which is the passage length 1 (Fig. 1) corresponds to the collector plates. The collector plates 28 can then individually perpendicular to the circular Disc 42 can be welded on and the unit can then be welded to a flat leg part 44 of the rotary drum 36.

As FIG. 2 clearly shows, one end of each charging wire 26 extends by an electrically insulated recess in the side wall 30 of the housing 12, with the charging wire in the side

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wall is supported by the isolating agent J54. The outstanding one End forms a terminal 46 which is connected to one side of the high voltage power source. Any known Arrangement may be provided to connect the collector plates to the opposite side of the power source. Means a brush holder 48, which is held in electrically conductive contact with the shaft 38, the collector plates for example via the terminal 50 of the brush holder directly be coupled to the other side of the high voltage power source. Since the charging wires are outside the space between the Collector plates are arranged, this not only allows more collector plates in a precipitation device of certain Size can be used, but also that, if desired, between the charging wires and the collector plates maintain a higher tension and thereby increase the effectiveness of the collection. A corresponding The power source would be a DC power source of 10-50 kV * The invention however, it is not limited to this example, since an alternating current source and / or different voltage ranges can also be used.

In particular, Pig. Reference is made to 3 in which, for purposes of illustration, the substantially uniform electric field is represented by the voltage difference between the charging wires 26 and the collector plates 28 is generated. As can be seen from the detailed illustration of FIG. 3, this is between the charging wires 26 and the Collector plates 28 generated electric field (illustrated by the broken lines and generally with

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the reference numeral 50 denotes) arranged so that it with the direction of flow 18 of the incoming dust-laden Gas collapses. Therefore, if the flow 18 of the dust-laden Gas through inlet port 14 into the precipitator 10 occurs, all dust particles pass through the substantially uniform electric field 50, whereby they are charged and thrown against the collector plates 28 where the particles are on a very short passage length are collected .. The purified gas flow passes between the collector plates 28 and passes through the Outlet opening 16 from.

In Pig. 3 it was found that the subset of the particles which is collected as a puncture of the passage length 1 of the collector plates decreases very rapidly from a maximum in the case of short and closely spaced collector plates. For example, for a distance between the collector plates of approximately 12.5 mm, the increase in the subset of particles that are collected in the case of collector plates with a passage length 1 of 200 mm is only 5% compared to collector plates with a passage length of 100 mm. It is therefore preferable to use fairly short and closely spaced collector plates 28. To illustrate the principles of the invention, in a preferred embodiment, collector plates at least 100mm in length spaced about 12.5mm apart are the most desirable arrangement. Of course, the advantages of the present invention can, in accordance with the teachings given above, also be used with other plate sizes and spacings.

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be realized.

In any case, it should be noted in particular that the collector plates according to the present invention can be greatly reduced in size over any known arrangement can. This enables the present precipitation device, to utilize the desired high flow rate of the incoming gases. For example, it is desirable that a precipitator can work directly in the usual gas flows with flow velocities of 15-50 m / s. this was not possible with the known precipitation devices because the sizes of the known collector plates require that the incoming gas flow is slowed down to a flow velocity of 3 m / s. The solution to this problem allows hence the effective operation of the precipitating device according to the invention in the existing gas flows with high flow velocities.

If desired, the panels can be curved to provide additional support adapt to aerodynamic requirements, such as a low flow loss or a larger surface area or more efficient collection than a flat plate, or for all of these reasons.

The operation of the precipitation device according to the invention in a gas flow with a high flow velocity enables the Fixed charging wires, kept free of randomly deposited dust particles by an aerodynamic FaTL tt he vibration to become. If desired, the charging wires can be arranged in circular

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or tape shape can be arranged to clean the wires through

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to amplify the aerodynamic flutter vibrations.

Figures 1 and 2 show an arrangement for cleaning the Collector plates from the deposited particles in such a way that which is not possible with the known precipitation devices. As already mentioned, there is a cleaning liquid return line at the bottom of the housing 12 22 and a drying air return line 24 is arranged. Both return lines 22 and 24 have an end 52 which extends into the housing 12 extends to with one end of the collector plates 28 in sealing Intervention to come. As FIG. 2 clearly shows, an extended cleaning section 5 ^ of the housing extends 12 from the side wall 30 against the side wall 32 of the housing, as well as within the rotary drum 36 to with the inner End of the collector plates 28 to come into sealing engagement. The collector plates 28 can therefore be cleaned or treated by adding an appropriate liquid, e.g. Water, oils or solutions through the hole in a housing flange 56 is introduced. When treating oletim fume (which contains sulfuric acid) or corrosive dust can affect the cleaning liquid contain neutralizing reagents. The cleaning liquid is introduced into the cleaning section 5 ^, passes between the collector plates 28 and occurs through the liquid return line 22.

As FIG. 1 "clearly shows, the precipitator also contains a drying or treating section 58 in which, for example, air is introduced at high speed to pass between the cleaned collector plates.

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go and exit through the return line 24. To the To protect the plates 28, the drying section can be omitted and the plates can be coated with a film of a cleaning or treatment liquid which is absorbed by the Housing flange 56 in the cleaning or treatment section 54 is introduced. A liquid film consisting of another liquid can also be used for this purpose through the Drying or treatment section 58 are supplied. In In any case, the treatment liquid for the gas treatment can be acidic or alkaline. Such a liquid For example, it can be used to treat one with a sulfur compound loaded gas be an alkaline solution. In this case, the collector plates 28 are abundantly wetted with the solution and in the precipitator, not only can the dust and mist be collected but also undesirable ones Vapor constituents are reduced in the incoming gas flow.

Because the dust and mist are endowed with natural electrical charges the failure device will also collect the dust and haze without turning on the rim or charging wires although the performance is reduced. When the collector plates 28 in the manner indicated above with a If the liquid film is treated, the vapor components of the dust-laden gas without using the ring or the charging wires removed.

In particular, it should be noted that when using a high voltage DC power supply the grounded terminal of the source with

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the terminal 50 can be connected and thereby the collector plates 28 must be earthed. The other side of the DC source is of course connected to the charging wires via the terminals 46 26 connected. Since, according to FIG. 1, there are no charging wires in the portion of the housing 12 in which corresponding seals limit a cleaning liquid section and a drying air section, it is not necessary to feed the during the cleaning process To interrupt or switch off the high-voltage current. The precipitator according to the invention therefore eliminates the circuit the Hochspannungsstromqejullen during the cleaning process, which is required with the known precipitation devices is.

Although the principles of the invention are based on the preferred Embodiment of a rotatable electro-aerodynamic precipitation device having been illustrated can be understood by those skilled in the art using the teachings given above develop modified embodiments of the invention. For example can using a series of stacked stationary collector plates and stationary charging wires Easily an electro-aerodynamic precipitator can be constructed to between the charge wires and the collector plates in the direction of the flow of the entering dust-laden Gas to generate the electric field, as shown in Fig. J5.

A modified arrangement of the configuration shown in FIGS. 1 and 2 can also be provided, in which the

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relative positions of the stationary charging wires 26 and the collector plates 28 can be reversed. The fixed ones Charge wires 26 can surround an inlet opening in a ring-like arrangement, while the collector plates 28 on a Rotary drum are arranged, the diameter of which is larger than the diameter of the ring of the charging wires. The current the dust-laden gas can then enter through the axial inlet opening within the ring of the wires. The gas flow is therefore cleaned by the same through the charging wires, the substantially radial electric field and the Collector plates 28 passes and finally exits through an outlet opening.

It is also possible to have levels of rotating or stationary electro-aerodynamic precipitators to be stacked in series or in parallel. That is, the one shown and described above Design can also be designed in several stages for the purpose of thorough cleaning. Referring to Fig. 1, requires this is a second rotating drum with a series of collector plates 28, the drum having a diameter, which is larger than the diameter of the first ring of charging wires shown in FIG. Then a second ring of Fixed charging wires provided, wherein the ring has a diameter which is larger than the diameter of the second Rotary drum. In other words, the incoming gas flow would be through two or more sets of charge wires and collector plates of the type shown in Fig. 1 pass therethrough. When in the above-mentioned modified configuration, the charging wires can be placed in a ring smaller in diameter than the rotating drum, a second set of

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similarly arranged charging wires and a rotating drum are provided will.

The invention is not limited to those shown and described example embodiments that limit the various Changes can be made without departing from the scope of the invention.

Claims

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Claims (1)

Dr. Ing. E. BERKENFELD · üipl.-lng. H. BERKENFELD, Patentanwälte, Cologne Attachment file number to the Bngobev of April 1, 1968 Sch // Named.Anm. University of Illinois Foundation claims 1. ι electro-aerodynamic precipitation device, marked by a housing having an inlet opening for receiving a flow of dust-laden gases and an outlet opening 'to discharge the cleaned gases, through a R, .ng of conductive wires connected to the one-polarized side of a high-voltage power source, by means of insulating support of the dust-laden gases which lie in the path of the dust-laden gases entering through the inlet opening conductive wires on the housing, rotatable through one in the housing mounted rotatable part, the interior of which is in communication with one of the openings of the housing, through a plurality of closely spaced collector plates, which on the circumference of the rotatable part immediately adjacent to the ring of the conductive wires, as well as between this ring and the outlet opening are arranged, the collector plates with the the opposite polarity side of the high voltage power source are connected, so that between the Conducting wires and the collector plates generated electric field essentially with the flow direction of the dust-laden Gases is aligned. - 16 - _ \ .fjgQÜ 3 / H 3 1 _BAD 2. Precipitation device according to claim T, characterized in that that the collector plates are at a distance of 12.5 mm or less from each other. 3 · Failure device according to claim 1, characterized by means of cleaning the collector plates without switching off the power source from the panels. Ψο precipitation device according to claim 1, characterized by means of treating the collector plates with a solution for the purpose of removing unwanted vapor components from the gas flow. ' 5 Multi-stage electro-aerodynamic precipitation device, which contains the combination according to claim 1, characterized by a second plurality of closely spaced collector plates that are in the way of the rotatable part the gas flow exiting the first collector plates, as well as being arranged between the outlet opening and the first collector plates, and through a second ring of conductive wires, which are supported between the first and second collector plates on the housing in an insulating manner, so that the gases entering through the first ring of conductive wires, the first collector plates, the second ring of conductive wires and the second collector plates pass through and out of the housing through the outlet port step out. - 6. precipitator according to / claim 2, characterized in that the outlet opening ₃ of the housing in communication with the interior of the rotatable part is arranged and that the ring , 109853/1431 BAO ^ - -17- of the conductive wires on the housing at a location outside the interior of the rotatable part and slightly outside the circumference of the rotatable part is supported in an insulating manner, so that the flow entering through the inlet opening of the dust-laden Gases through the ring of conductive wires, through the collector plates and through the interior of the rotatable member and exits the housing through the outlet opening., 7. precipitation device according to claim 2, characterized in that the inlet opening on the housing in connection with the interior of the rotatable part is arranged and that the ring of conductive wires on the housing within the interior of the rotatable Is partially supported in an insulating manner, so that the gas flow entering through the inlet opening through the ring of the conductive Wires within the interior of the rotatable member and through the collector plates and exits through the outlet opening located outside the interior of the rotatable member. 8. precipitation device according to claim 2, characterized in that the conductive wires during the passage of the dust-laden gases can run fluttering vibrations, as a result of which any accidentally deposited on the wires Dust particles are removed. 9. Electro-aerodynamic precipitator, marked by a housing having an inlet opening for receiving a flow of dust-laden gases and an outlet opening for the discharge of the purified gases, through a large number of conductive wires, which have one polarity with the one Side connected to a high voltage power source, through 109853 / U31 BAD OR.QINAU - _ia - Means for insulating support of the in the way of through the Inlet opening entering dust-laden gases lying conductive Wires on the housing, through a variety of collector plates, which are at a distance of 12.5 him or less' from each other and those on the housing between the wires and the outlet opening, soxvie immediately adjacent to the conductive ones Wires are arranged., The collector plates with the the opposite polarity side of the high voltage power source are connected so that the electric field generated between the conductive wires and the collector plates in the is essentially aligned with the direction of flow of the dust-laden gases » - 19 .1098 53/1 £ '3Ί