WO2023135048A1

WO2023135048A1 - Electrostatic dust separator

Info

Publication number: WO2023135048A1
Application number: PCT/EP2023/050151
Authority: WO
Inventors: Thilo WÜBBELS; Joachim Rotarius
Original assignee: Sms Group Gmbh
Priority date: 2022-01-12
Filing date: 2023-01-05
Publication date: 2023-07-20
Also published as: DE102022200243A1

Abstract

The invention relates to an electrostatic dust separator (10) for horizontal gas passages, comprising a cylindrical housing (12), within which at least one precipitation field (13) with precipitation electrodes (14) and spray electrodes (15) arranged therebetween is provided, at least one dust discharge opening (16), which is formed in the base region of the housing (12), at least one scraping device (17), which is arranged in the lower half of the cylindrical housing (12) and so as to adjoin the inner circumferential surface of the housing (12), wherein the scraping device (17) is rotatably mounted about a pivot axis (A1) which runs in the longitudinal direction of the housing (12), and drive means, by means of which the scraping device (17) can be pivoted back and forth about the pivot axis such that when the scraping device (17) is pivoted about the pivot axis, dust particles that have settled in the base region of the housing (12) are released by the scraping device (17) and can be successively introduced into the dust discharge opening (16). The drive means are arranged outside of the housing (12) and interact with the scraping device (17) via at least one paired connection element.

Description

Electrostatic dust collector

The invention relates to an electrostatic dust separator according to the preamble of claim 1 .

According to the prior art, electrostatic dust separators have been known for decades for cleaning flue gas. For example, a generic dust separator is shown in DE 1900526A. In such a dust separator, there are drive elements for a scraper device, which is suspended in the lower semi-cylinder of a cylindrical housing and supported about a pivot axis, in the form of a drive shaft and pinions cooperating therewith, directly inside the housing. The consequence of this is that these drive elements are exposed to the harmful atmosphere inside the housing and to the high temperatures prevailing therein, which has a negative effect on the service life and operational reliability of these drive elements. A further disadvantage of a dust separator according to DE 1900526A is that only two electrical precipitation fields are provided in its housing along its longitudinal axis and in this respect the maximum achievable degree of purification for the flue gas is limited.

Another prior art dust separator is known from CN 205903986 U, for example. In the same way as already explained for DE 1900526A, this dust separator also comprises a scraper device which is pivotably suspended within the housing, with associated drive elements for this scraper device, namely in the form of a pinion and a toothed rack cooperating therewith, being arranged directly inside the housing. The resulting disadvantages are the same as those already explained above for DE 1900526A. Furthermore, it is known from the prior art for electrostatic dust separators with a cylindrical housing that pivotable scraper devices are driven jointly about a pivot axis and thus about the pivot axis by two electrical precipitation fields arranged next to one another within the housing by a lance-shaped or lantern-shaped drive shaft - and are moveable. In addition to the disadvantage of a complex and therefore fault-prone construction, such a common drive technology is unfavorable for a plurality of scratching devices because it cannot be used to set a different frequency for different scratching devices.

Accordingly, the object of the invention is to optimize the drive technology for an associated scraper device for an electrostatic dust separator.

This object is achieved by an electrostatic dust separator having the features of claim 1. Advantageous developments of the invention are defined in the dependent claims.

An electrostatic dust separator according to the invention is intended for a horizontal gas passage, and for this purpose comprises a cylindrical housing which is arranged horizontally and can be flowed through by flue gas along its length. In a known manner, the housing has openings on each of its two end faces for this purpose, through which the smoke gas can flow into and out of the housing. At least one precipitation field with precipitation electrodes and discharge electrodes arranged between them is provided within the housing. The collecting electrodes can, in particular, be designed in the form of plates and each be arranged vertically within the housing. At least one dust discharge opening is formed in a bottom area of the cylindrical housing. Furthermore, the dust separator according to the invention comprises at least one scraping device, which is arranged in the lower half-cylinder of the housing and adjacent to the inner peripheral surface of the housing, the scraping device being rotatably mounted about a pivot axis running in the longitudinal direction of the housing. The dust separator according to the invention also includes drive means, by means of which the scraper device can be pivoted back and forth about the pivot axis, namely in such a way that when the scraper device is pivoted about the pivot axis, dust particles that have settled in the bottom area of the housing are removed from the Scratch device are solved and thereby successively in the dust discharge can be introduced. The drive means are arranged outside of the housing and are operatively connected to the scratching device via at least one associated connecting element. The drive means are designed in such a way that a linear actuating force that can be transmitted to the scratching device can be generated, with the direction of this linear actuating force running tangentially to the circumference of the housing.

In the dust separator according to the invention, a separate scraper device is provided for each of its electrical precipitation fields, which is rotatably mounted about the pivot axis running in the longitudinal direction of the housing and is attached by means of associated struts to a pivot bearing, through which this pivot axis runs. The lower edge of the scratching device is designed in such a way that it is arranged hanging on the pivot bearing in such a way that it is adapted to the round bottom area of the housing and is only at a small distance therefrom. Accordingly, with a "rocking movement" that is achieved when the drive means for the scraper device is actuated about the pivot axis, it is possible for dust particles that have settled in the bottom area of the housing to be loosened or whirled up by the scraper device and thus in the direction the dust discharge opening are moved or promoted. The present invention is based on the essential finding that the drive means, with which an associated scratching device can be driven to move back and forth about the pivot axis within the housing, are exposed to a lower thermal load because these drive means are arranged outside the housing. Such an arrangement of the drive means can be achieved with the aid of at least one associated connecting element which is guided through an opening in the housing and in this respect ensures an operative connection between the drive means arranged outside the housing and the scratching device located inside the housing.

The above-described attachment of the drive means outside the housing of the dust separator can be implemented in a simple manner by providing a fastening plate or the like on an outer peripheral surface of the housing, to which the drive means are attached.

A further advantage of the present invention is that an independent or separate drive can be implemented in a simple manner for a plurality of scratching devices which are assigned to the individual electrical precipitation fields within the housing and thus also for these scratching devices, if necessary different drive parameters (e.g. amplitude, frequency) can be set, with which these scratching devices are moved back and forth around the pivot axis according to a “rocking movement”. This is possible because the individual drive means are arranged on a longitudinal side edge of the housing and are assigned to a respective scratching device and in this respect a simple operative connection with the assigned scratching devices can be achieved over only a short distance using the connecting elements.

In an advantageous development of the invention, a scratching device of a respective precipitation field - in a plane orthogonal to the longitudinal extent of the housing - extend along the bottom portion of the housing by an angle having a value between 110° and 130°. This means that the lower edge of the scratching device runs parallel to or along the round inner peripheral surface of the cylindrical housing by this angle. This angle can preferably assume a value of 120°. This ensures that dust particles that have settled in the bottom area of the housing in its lower half-cylinder are caught over a large area or in a wide area by the scratching device during its “rocking movement” around the pivot axis.

The drive means, with which in the dust separator according to the invention a scraping device of a respective electrical precipitation field is set in a "rocking motion" about the pivot axis, can be designed as: linearly actuable actuating cylinder, for example in the form of a pneumatic cylinder or a hydraulic cylinder, or electric linear drive, or electric spindle drive, or

Cable winch or the like, preferably motor-driven, namely in the event that a connecting element for realizing an operative connection with the scratching device is designed in the form of a cable.

A mechanically simple and at the same time robust design of a connecting element, through which the drive means are operatively connected to a scratching device, can be implemented, for example, by a coupling rod. Such a coupling rod is used to exert a linear actuating force, ie alternating tensile and compressive forces tangential to the housing circumference, on a scratching device, thereby achieving a desired “rocking movement” of the scratching device about the pivot axis running in the longitudinal direction of the housing. In an advantageous further development of the invention, it can be provided for the coupling rod just mentioned that it is connected in an articulated manner to the scratching device. Optionally, the opposite end of the coupling rod, which faces the drive means, is also connected in an articulated manner to these drive means. In any case, these articulated connections provided for the coupling rod effectively avoid possible tensions, inclined positions or the like, which could otherwise be generated for the coupling rod when the drive means is actuated and the linear actuating force generated thereby.

In an advantageous development of the invention, it can be provided that the coupling rod is designed in multiple parts and these parts of the coupling rod are connected to one another in a pivoted manner. This also ensures that when the drive means is actuated, possible stresses on the coupling rod do not occur or cannot arise in the first place.

In an advantageous development of the invention, it can be provided that, if a connecting element is designed in the form of a coupling rod, then the drive means are movably connected to the fastening plate provided on an outside of the housing. This mobility can be achieved by a rotary joint and/or by rubber elements that are designed to be flexible and elastic. In any case, such a movable mounting of the drive means on the fastening plate has the advantage that when the drive means is actuated, it is possible to compensate for possible tension or the like for the coupling rod.

In an advantageous development of the invention, a connecting element, if it is in the form of a coupling rod, can also be part of a joint mechanism by which the scratching device is operatively connected to the drive means. Such a joint mechanism can expediently comprise a pivoted lever and/or a toggle lever, for example in the form of those mentioned connecting rod. In any case, the advantage is achieved by such a joint mechanism that the required stroke or travel of the drive means can be reduced.

If the drive means are designed as hydraulic or pneumatic cylinders, according to an advantageous development of the invention, it can be provided that with a sufficiently long piston rod of such an actuating cylinder, such a piston rod simultaneously fulfills the function of a connecting element with which an operative connection with an associated scratching device is realized . This means that such a piston rod, with a sufficiently large length, is then connected with its free end directly to an edge region of an associated scratching device, preferably in an articulated manner.

As already explained, as an alternative to a coupling rod, the connecting element can also be designed in the form of a pulling cable, with which a pulling force is then exerted on the scratching device from one side. In view of the fact that no compressive forces can be exerted with such a cable, in this case drive means, for example in the form of a motor-driven cable winch or the like, are provided on both sides of the housing, viewed in the direction of the longitudinal extent of the housing, i.e. on its longitudinal sides and each associated with a scratch device. In other words, in this case a scratching device is controlled from both sides by means of pull cables in order to achieve a desired “rocking movement” around the pivot axis for the scratching device.

Exemplary embodiments of the invention are described in detail below using a schematically simplified drawing. Show it:

1 is a perspective view of a dust separator according to the invention, the housing of which is shown partially cut away to illustrate associated components, FIG. 2 shows a cross-sectional view through the housing of the dust separator from FIG. 1 , and

3 is a simplified and enlarged end face and cross-sectional view of a longitudinal strut that is part of a scraper device of the dust separator of FIGS. 1 and 2, respectively.

In the following, with reference to FIGS. 1 to 3, preferred embodiments of an electrostatic dust separator 10 are explained, by means of which the flue gas, which is loaded with dust particles, can be intensively and efficiently cleaned. The same features in the drawing are each provided with the same reference symbols. At this point it is pointed out separately that the drawing is merely simplified and, in particular, is not shown to scale.

According to the perspective view of FIG. 1, the dust separator 10 comprises a cylindrical housing 12, on the end faces of which are formed an inlet area 30 and an outlet area 40 with associated openings. Accordingly, it is possible for flue gas to enter the housing 12 of the dust separator 10 through the inlet area 30, flow through the housing 12 along the longitudinal axis L and then exit the housing 12 again through the outlet area 40, now thoroughly cleaned.

A total of four electrical precipitation fields 13 are provided along the longitudinal axis L of the housing 12 for the dust separator 10 according to the invention according to the embodiment of FIG. In each of these precipitation fields 13 precipitation electrodes and spray electrodes arranged between them are provided.

Fig. 2 shows a simplified cross-sectional view through the housing 12 of Fig.

1. Here it can be seen that the collecting electrodes - here referred to as "14" - each plate-shaped and designed within the housing are arranged vertically. Discharge electrodes can be arranged in a known manner between the collecting electrodes--in FIG. 2, for example, at a position labeled "15".

In the perspective view of Fig. 1, the collecting electrodes 14 and discharge electrodes mentioned above are not shown because of the cut-away part and for the purpose of simplifying this view.

A plurality of dust discharge openings 16 (cf. FIGS. 1, 2) are formed in the bottom area of the housing 12 along its longitudinal axis L. FIG. In the embodiment of Fig. 1, these dust discharge openings 16 are in the form of triangles and, as can be seen in Fig. 2, are each in the center M of the lower half-cylinder of the housing 12. It goes without saying that these dust discharge openings 16 can also have a shape deviating from triangles. The importance of these dust discharge openings 16 is explained separately below.

The dust separator 10 according to the invention comprises a plurality of scraping devices 17, individual scraping devices 17 each being associated with a specific electrical precipitation field 13. In other words, each electric precipitation field 13 has a separate scratch device 17.

The structure of a scratching device 17 is explained in detail below:

A scratching device 17 comprises two side struts, each of which runs along a lateral edge of the scratching device 17 and—in adaptation to the round shape of the bottom region 11 of the housing 12—are designed in the form of an arc of a circle. In FIG. 1, these side struts in the electrostatic precipitation field 13, which is directly adjacent to the inlet area 30, are each designated with an “S”. Furthermore, a scratching device 17 comprises a plurality of longitudinal struts 26 which each run in the longitudinal direction L of the housing 12 and are fitted between the side struts S. Thus, these longitudinal struts 26 are each arranged adjacent to one another in a plane orthogonal to the longitudinal axis L of the housing 12 . To stabilize these longitudinal struts 26, the scratching device 17 also includes a plurality of auxiliary struts H (see FIG. 1), which are arranged between the side struts S and parallel thereto and are fastened thereto at the crossing points with the longitudinal struts 26.

A plurality of carriers T are provided within the housing 12 adjacent to the individual electrical precipitation fields 13, namely a total of five. These supports T each run in a plane orthogonal to the longitudinal axis L of the housing. Two of these carriers T are each arranged adjacent to the end faces of the housing 12 (i.e. adjacent to the inlet area 30 or the outlet area 40), with the remaining three carriers each separating the total of four electrical precipitation fields 13 from one another.

In the individual carriers T, a pivot bearing 19 is preferably attached in a central area thereof. With regard to these rotary bearings 19 in the individual carriers T, it goes without saying that these are preferably aligned exactly with one another and thus jointly define a pivot axis Ai (cf. FIG. 3). This pivot axis Ai runs parallel to the longitudinal axis L of the housing 12.

Two struts 18 are attached to a side strut S of the scratching device 17, preferably to the two end sections thereof, which are attached to the pivot bearing 19 of an associated carrier T with their opposite ends. Thus, a total of four struts 18 are provided for the embodiment shown in FIG associated carrier T is suspended and thus pivotable about the pivot axis Ai.

Fig. 3 shows an enlarged and simplified front or side view of a longitudinal strut 26. The plane of the drawing runs orthogonally to the longitudinal axis L of the housing 12.

According to FIG. 3, a longitudinal strut 26 (shown here in bold black lines) has a first leg 27 and a second leg 28—seen in a plane or in cross section orthogonal to the longitudinal axis L of the housing 12. The first leg 27 runs essentially radially in the direction of the pivot axis Ai of the scratching device 17 or to an associated rotary bearing 19, which is symbolized in FIG. 1 by a dot-dash line. The second leg 28 is longer than the first leg 27, with the second leg 28 extending from an end of the first leg 27 facing the pivot axis Ai of the scratching device 17, away from the center M of the lower half-cylinder of the housing 12, outwards in the direction of a Edge region R of a scratching device 17 extends and is longer than the first leg 27 is formed.

With regard to the design of a longitudinal strut 26, as just explained in connection with FIG. 3, it goes without saying that all longitudinal struts 26 of a respective scratching device 17 can be designed in this way. In this context, it may also be pointed out that the plurality of longitudinal struts 26 according to FIG. This means that the individual longitudinal struts 26 are positioned in relation to this center M or on both sides thereof in such a way that the first leg 27 faces the center M in each case. The meaning of this is explained separately below. With regard to the above configuration of a scratching device 17, it is understood that this applies expediently to all scratching devices 17 that are assigned to the individual electrical precipitation fields 13.

As already explained above, a total of four electrical precipitation fields 13 are formed in the housing 12 in the embodiment of FIG. 1, with separate precipitation electrodes 14, discharge electrodes and scratching devices 17 being provided for each precipitation field. Separate drive means 20 are assigned to each scratching device 17 of an individual precipitation field 13, with which a scratching device 17 can be driven in the manner of a swing in order to achieve a pivoting or rocking movement for the individual scratching devices 17 about the pivot axis Ai.

Further details relating to the drive means 20 are explained below.

On an outside of the housing 12, namely on a longitudinal side edge thereof (indicated by “I” in FIG. 2), a fastening plate P is attached to which the drive means 20 are connected. As already explained elsewhere, these drive means 20 can be in the form of hydraulic cylinders or pneumatic cylinders, or in the form of a linear or spindle drive, preferably electrically driven. In any case, a linear actuating force is generated with such drive means 20, which is transmitted to the scratching device 17 with the aid of at least one associated connecting element 22. As a result, a torque about the pivot axis Ai is transmitted from the drive means 20 to an associated scratching device 17, which is thus set in a rocking motion about the pivot axis Ai.

According to the representation of FIG. 2, a connecting element 22, with which an operative connection between the drive means 20 and a scratching device 17 is realized, can be designed in the form of a coupling rod. Here is from Meaning that adjacent to the point at which the mounting plate P is attached to the outside of the housing 12, an opening 24 is formed in the wall of the housing 12, through which the coupling rod 22 (or also a piston rod of a hydraulic or pneumatic cylinder) extends. It is thus possible for the drive means 20 per se to be arranged completely outside of the housing 12, which leads to the advantages already mentioned at the outset.

A coupling rod 22 can be connected in an articulated manner to a respectively assigned scratching device 17, preferably at an edge region R thereof (cf. Fig. 1) and at an end section of a longitudinal strut 26.

If the drive means 20 are embodied as a hydraulic cylinder, it can be attached to the outside of the housing 12 in such a way that an end face of such a hydraulic cylinder rests against an opening 24 formed in the wall of the housing 12 and seals suitably with the edge of this opening 24. In this case, the piston rod of such a hydraulic cylinder is passed through the opening 24 and aligned in the direction of the edge region R of an adjacent scratching device 17 . The hydraulic seal of the piston of the hydraulic cylinder thus simultaneously achieves a gas-tight seal of the housing 12 at the point where the hydraulic cylinder 20 is attached to the outside of the housing 12 in the area of an opening 24 .

In the illustration of FIG. 1, arrows “20” symbolize that each individual scratching device 17 is driven by two drive means 20, for example in the form of a hydraulic cylinder. In this case, an associated coupling rod 22 is attached to a piston rod of a hydraulic cylinder, which is then connected to an end section of a longitudinal strut 26 of this scratching device 17, preferably in an articulated manner. With regard to a mounting plate P, on which the respective drive means 20 are attached to an outer side of the housing 12, it is pointed out separately at this point that this can be a continuous plate that is attached to an outer wall of the housing 12 along whose longitudinal extent runs. As an alternative to this, it is possible, for example, for a separate fastening plate P to be provided on the outside of the housing 12 for each individual hydraulic cylinder, as a result of which material can advantageously be saved.

With regard to the drive means 20, it should be emphasized that these can be movably attached to the mounting plate P, for example by means of a joint with an axis of rotation A2 (cf. FIG. 2) which runs parallel to the longitudinal axis L of the housing 12.

According to a further embodiment (not shown), it is possible for the drive means 20 to be designed in the form of a cable winch. In this case, the connecting elements 22 consist of cables or the like, with which an operative connection between a cable winch and an edge region R (cf. FIG. 1) of an associated scratching device 17 is realized. In this case, a cable, like a coupling rod, is passed through an opening 24 formed in the housing 12 in order to achieve the said operative connection between a cable winch arranged on the outside of the housing 12 and a scratching device 17 located inside the housing 12. In this context, it may be pointed out that the drive means 20 in the form of cable winches are then arranged on both sides of the housing 12 on its longitudinal side edges (designated with “I” and “II” in FIG. 2).

Irrespective of the configuration of the drive means 20, it can be provided for the dust separator 10 according to the invention that a scraper device 17 of a respective electrical precipitation field 13 is driven by at least two such drive means 20 about the pivot axis Ai, correspondingly of the arrows “20”, with which the respective positions of these drive means 20 are symbolized in FIG. Deviating from this, it is also possible either to provide only one drive means 20, which is then operatively connected to an edge region R of an associated scratching device 17, preferably in its center, or to provide three or more such drive means 20 per scratching device 17.

In the case of a cable drive, it is expedient to arrange the drive means 20 in the form of cable winches, as explained, on both sides of the housing 12 on its longitudinal side edges, with the cables that are assigned to the individual cable winches then being attached to the opposite edge regions R of a scratching device 17.

The invention now works as follows:

During operation of the dust separator 10 according to the invention, flue gas loaded with dust particles is introduced into the housing 12 through the inlet area 30 . As a result, the flue gas then flows through the housing 12 along its longitudinal axis L and thus also through the individual electrical precipitation fields 13 provided therein. This usually results in dust and/or dirt particles, which are initially deposited on the precipitation electrodes 14 fall by knocking down on the bottom portion 11 of the lower half cylinder of the housing 12 and collect there.

In order to now efficiently discharge fractions of dust and/or dirt from the bottom area 11 of the housing 12 to the outside, the drive means 20 of the individual scraping devices 17 are actuated and the scraping devices 17 are thereby moved back and forth about the pivot axis Ai, in the manner of a rocking motion.

The aforementioned rocking movement, which occurs for a respective scratching device 17, is explained with reference to the illustration in FIG. Herein is a longitudinal strut 26, which as explained is part of such a scraping device 17, is shown in solid lines at a first time when it has been moved by the drive means 20 towards the center M of the lower half-cylinder of the housing 12. Proceeding from this, the scratching device 17 is then moved away from the center M, so that the longitudinal strut 26 shown reaches the position symbolized by dashed lines. In the course of this movement, the second leg 28 moves into a dust and/or dirt fraction that has accumulated on the floor area 11, as a result of which the dust and/or dirt particles slide over the slope of the second leg 28 and fall back down in front of the first leg 27 . When an opposite movement is initiated, i.e. when the longitudinal strut 26 shown in FIG Dirt particles are conveyed along the bottom area 11 in the direction of the dust discharge openings 16 . Through a cyclic sequence of such a back and forth movement of a scraper device 17 about the pivot axis A1, in the manner of a rocking movement, dust and/or dirt particles are then successively introduced into the dust discharge openings 16 and thereby fall downwards out of the housing 12.

With regard to the back and forth movement explained above, which is set for a scratching device 17 during its “rocking movement” about the pivot axis A1, a distance a is shown in FIG. 3, which can correspond to an amplitude of a scratching device 17 during its rocking movement . In connection with an actuation of a scraper device 17 by the drive means 20, this distance a corresponds to a working stroke (e.g. of a linear actuating cylinder in the form of a hydraulic or pneumatic cylinder) which, when a scraper device 17 moves between the two positions shown in Fig. 3, the drive means 20 is exerted. This applies in the same way to the design of the drive means 20 for example in the form of hydraulic cylinders or alternatively in the form of cable winches.

The cross-sectional view of Fig. 2 illustrates a diameter D of the housing 12. In this regard, it should be pointed out that the drive means 20 can be designed in such a way that the linear actuating force generated therewith or its working stroke, which according to the illustration in Fig. 3 the distance a assumes, for example 5 - 10%, preferably 6 - 9%, of the diameter D of the housing 12 can assume. It is noted here that the working stroke of the drive means 10, in accordance with the distance a shown in Fig. 3, either assumes exactly the specified limit values, i.e. the values 5, 10, 6 or 9% of the housing diameter D, or any values between these limit values can.

Analogously to the different positions that are assumed in FIG. 3 by a longitudinal strut 26 or by an associated scratching device 17 during its rocking movement, FIG. 2 also shows a total of three discrete positions for the struts 18 for a scratching device 17. with which a scratching device 17 is articulated to a rotary bearing 19 as explained.

As also illustrated by FIGS. 2 and 3, the pivoting angle at which a scratching device 17 is moved about the pivoting axis Ai when controlled by the drive means 20 can be approximately 7-10°. This can correspond to the condition mentioned above, according to which the distance a (cf. FIG. 3), which corresponds to the working stroke of the drive means 20, assumes a value which is approximately 5-10%, preferably 6-9%, of the housing diameter D .

With the help of a joint mechanism or the like, which can be provided for the connecting element 22 and can comprise, for example, a pivoting lever and/or toggle lever, it is possible to further reduce the to achieve working strokes of the drive means 20, with the amplitude remaining the same for a respective scratching device 17.

For the aforementioned operation of a dust separator 10 according to the invention, it should be emphasized that the operation of the dust separator 10 does not have to be interrupted for the explained removal of dust and/or dirt particles from the housing 12 with the aid of the scraping devices 17 . In other words, permanent removal of dust and/or dirt particles is effectively ensured by means of the present invention during ongoing operation of the dust separator 10 .

According to a further (not shown) embodiment of the invention, it is possible for more than four electrical precipitation fields 13 to be provided in the housing 12 of the dust separator 10, for example five, six or even more such electrical precipitation fields. A further improved cleaning for the flue gas within the housing 12 is thereby achieved.

Finally, it should be pointed out again that the individual scratching devices 17, which are assigned to the respective electrical precipitation fields 13, can be driven independently of one another about the pivot axis Ai by their associated drive means 20. This allows for the fact that in the individual precipitation fields 13 along the longitudinal axis L of the housing 12 fractions of dust and/or dirt of different sizes are deposited on the bottom area 11 of the housing 12 . Reference List

10 dust collectors

11 bottom area (of the dust separator 10)

12 housing

13 precipitation electric field

14 precipitation electrode(s)

15 Position for attaching a discharge electrode

16 dust discharge opening

17 scraping device

18 strut(s)

19 pivot bearings

20 drive means

22 connecting element, e.g. in the form of a coupling rod

24 openings (in the housing 12, for the coupling rods 22)

26 longitudinal strut(s) (of the scratching device 17)

27 first leg

28 second leg

30 inlet area (of housing 12)

40 outlet area (of housing 12)

Ai pivot axis

A2 axis of rotation

D diameter (of housing 12)

H Auxiliary strut(s) (of the scratching device 17)

L longitudinal axis (of housing 12)

M center (of the lower half cylinder of the housing 12)

P mounting plate

R edge area (of a scratch device 17)

S side strut(s) (of the scratching device 17)

T carrier a working stroke or travel

Claims

Patent Claims:

1. Electrostatic dust separator (10) for horizontal gas passage, comprising a cylindrical housing (12), which is arranged horizontally and smoke gas can flow through along its length, wherein inside the housing (12) at least one precipitation field (13) with in particular plate-shaped precipitation electrodes ( 14) and discharge electrodes arranged between them, at least one dust discharge opening (16) which is formed in the bottom area of the housing (12), at least one scraper device (17) which is located in the lower semi-cylinder of the housing (12) and adjacent to the inner peripheral surface of the housing ( 12), wherein the scratching device (17) is rotatably mounted about a pivot axis (Ai) running in the longitudinal direction of the housing (12), and drive means (20) by which the scratching device (17) can be rotated about the pivot axis (Ai) can be pivoted back and forth in such a way that when the scraper device (17) is pivoted about the pivot axis (Ai), dust particles deposited in the bottom area of the housing (12) are released from the scraper device (17) and can thus be gradually introduced into the dust discharge opening (16). , characterized in that the drive means (20) are arranged outside the housing (12) and are operatively connected to the scratching device (17) via at least one associated connecting element (22), and in that the drive means (20) are designed in such a way that a linear actuating force that can be transmitted to the scratching device (17) can be generated, the direction of this linear actuating force running tangentially to the circumference of the housing. Dust separator (10) according to Claim 1, characterized in that a plurality of electrical precipitation fields (13) are formed in the housing (12), separate precipitation electrodes (14), spray electrodes and scraper devices (17) being provided for each precipitation field (13). , wherein each scraping device (17) of an individual precipitation field (13) is assigned separate drive means (20). Dust separator (10) according to Claim 2, characterized in that at least four or more than four precipitation fields (13) are formed in the housing (12). Dust separator (10) according to one of the preceding claims, characterized in that a fastening plate (P) is provided on an outside of the housing (12), to which the drive means (20) are connected, in particular movably. A dust collector (10) according to claim 4, characterized in that the drive means (20) are attached to the mounting plate (P) by means of a pivot (A2), the pivot (A2) being parallel to the longitudinal axis of the housing (12). Dust collector (10) according to claim 4, characterized in that the drive means (20) are attached to the mounting plate (P) by means of an elastic rubber bearing or the like. Dust separator (10) according to one of the preceding claims, characterized in that the drive means (20) are designed in the form of a linearly actuable actuating cylinder, in particular as a pneumatic cylinder or as a hydraulic cylinder, or in the form of an electric linear drive or an electric spindle drive.

8. Dust separator (10) according to claim 7, characterized in that the drive means (20) are designed in the form of an actuating cylinder or an electric linear or spindle drive in such a way that they have a working stroke or travel (s) for the linear actuating force generated thereby. have, which corresponds to 6% to 9% of the diameter (D) of the housing (12).

9. Dust separator (10) according to one of the preceding claims, characterized in that the connecting element (22) is in the form of a coupling rod or the like, preferably that the coupling rod is articulated to the scratching device (17), more preferably that the Coupling rod is designed in several parts and the parts of the coupling rod are pivotally connected to each other,

10. Dust separator (10) according to claim 9, characterized in that the coupling rod is part of a joint mechanism by which the scraper device (17) is operatively connected to the drive means (20), preferably that the joint mechanism comprises a pivoted lever and/or a toggle lever .

11. Dust separator (10) according to one of Claims 1 to 8, characterized in that the connecting element (22) is designed in the form of a cable, with drive means (20) - viewed in the direction of the longitudinal extension of the housing (12) - on both sides of the scraper device (17) are provided, so that the scratching device (17) can be moved back and forth about the pivot axis (Ai) by a cable pull.

12. Dust separator (10) according to one of the preceding claims, characterized in that struts (18) are attached to a side edge of a scraper device (17) of a respective precipitation field (13), the struts (18) having their opposite ends at one Pivot bearing (19) are mounted, through which the pivot axis (Ai) runs.

13. Dust separator (10) according to claim 12, characterized in that two struts (18) are provided per side edge of a scraper device (17) of a respective precipitation field (13), so that a respective scraper device (17) with a total of four struts (18 ) is hinged to the pivot bearing (19).

14. Dust separator (10) according to one of the preceding claims, characterized in that a scraper device (17) of a respective precipitation field (13) - seen in a plane orthogonal to the longitudinal extension of the housing (12) - extends along the bottom area (11) of the housing (12) extends through an angle having a value between 110° and 130°, preferably that the angle is 120°.

15. Dust separator (10) according to one of the preceding claims, characterized in that a scraper device (17) of a respective precipitation field (13) has a plurality of longitudinal struts (26) which each run in the longitudinal direction (L) of the housing (12) and are arranged adjacent to one another in a plane orthogonal to the longitudinal axis (L) of the housing (12), wherein a longitudinal strut (26) in a cross-section running in the plane orthogonal to the longitudinal axis (L) of the housing (12) has a first leg (27) and a second leg (28), the first leg (27) running essentially radially in the direction of the pivot axis (Ai) of the scratching device (17) and the second leg (28) extending from one of the pivoting axis (Ai) of the scratching device (17 ) facing end of the first leg (27) away from the center (M) of the housing (12) extends outwards and is longer than the first leg (27).