Electrostatic dust separator

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

[0001] The invention relates to an electrostatic dust collector according to the preamble of claim 1.

[0002] Electrostatic dust collectors have been known for decades for the purification of flue gases, according to the state of the art. For example, a dust collector of this type is shown in DE 1900526A. In such a dust collector, the drive elements for a scraper device, which is suspended in the lower half-cylinder of a cylindrical housing and mounted around a pivot axis, are located directly inside the housing in the form of a drive shaft and interacting pinions. This results in these drive elements being exposed to the harmful atmosphere within the housing and the high temperatures prevailing therein, which has a detrimental 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, to this extent, the maximum achievable degree of purification of the flue gas is limited.

[0003] Another prior art dust collector is known, for example, from CN 205903986 U. In the same way as already explained for DE 1900526A, this dust collector also comprises a scraper device that is pivotally suspended within the housing. Associated drive elements for this scraper device, namely in the form of a pinion and a cooperating rack, are arranged directly within the housing. The resulting disadvantages are the same as those already explained above for DE 1900526A.

[0004] Furthermore, it is known in the state of the art for electrostatic dust collectors with a cylindrical housing that pivoting scraper devices are jointly driven around a pivot axis by two electrical precipitation fields arranged side by side within the housing by a lance- or lantern-shaped drive shaft, allowing them to move back and forth around the pivot axis. In addition to the disadvantage of a complex and thus failure-prone design, such a shared drive technology is disadvantageous for multiple scraper devices because it does not allow for a different frequency to be set for each scraper device.

[0005] Accordingly, the invention is based on the object of optimising the drive technology for an associated scraping device for an electrostatic dust separator.

[0006] This object is achieved by an electrostatic dust collector having the features of claim 1. Advantageous developments of the invention are defined in the dependent claims.

[0007] An electrostatic dust collector according to the invention is designed for horizontal gas passage and, for this purpose, comprises a cylindrical housing that is arranged horizontally and through which flue gas can flow along its longitudinal extent. In a known manner, the housing has openings on each of its two end faces through which flue gas can flow into or out of the housing. Within the housing, at least one precipitation field with precipitation electrodes and spray electrodes arranged between them is provided. The precipitation electrodes can, in particular, be plate-shaped and each arranged vertically within the housing. At least one dust discharge opening is formed in a bottom region of the cylindrical housing.Furthermore, the dust separator according to the invention comprises at least one scraper device arranged in the lower half-cylinder of the housing and adjacent to the inner circumferential surface of the housing, wherein the scraper device is rotatably mounted about a pivot axis extending in the longitudinal direction of the housing. The dust separator according to the invention also comprises drive means by which the scraper device can be pivoted back and forth about the pivot axis, namely in such a way that, upon pivoting of the scraper device about the pivot axis, dust particles that have accumulated in the bottom region of the housing are released from the scraper device and can thus be successively introduced into the dust discharge opening. The drive means are arranged outside the housing and are operatively connected to the scraper device via at least one associated connecting element.The drive means are designed in such a way that a linear actuating force can be generated which can be transmitted to the scraping device, the direction of this linear actuating force being tangential to the circumference of the housing.

[0008] In the dust collector according to the invention, a separate scraper device is provided for each of its electrical precipitation fields. These scraper devices are mounted for rotation about the pivot axis running in the longitudinal direction of the housing and are attached by means of associated struts to a pivot bearing through which this pivot axis passes. The scraper device is designed with its lower edge and suspended from the pivot bearing in such a way that it is adapted to the round base area of the housing and is only a short distance from it. Accordingly, with a "rocking motion" achieved when the drive means for the scraper device is actuated about the pivot axis, it is possible for dust particles that have accumulated in the base area of the housing to be dislodged or stirred up by the scraper device and thus moved or conveyed towards the dust discharge opening.

[0009] The present invention is based on the essential finding that the drive means, with which an associated scraper device can be driven to move back and forth about the pivot axis within the housing, are subject to lower thermal stress 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 thus ensures an operative connection between the drive means arranged outside the housing and the scraper device located inside the housing.

[0010] The above-explained attachment of the drive means outside the housing of the dust collector can be realized in a simple manner by providing a mounting plate or the like on an outer peripheral surface of the housing, to which the drive means are attached.

[0011] A further advantage of the present invention is that it is easy to implement an independent or separate drive for a plurality of scraping devices assigned to the individual electric precipitation fields within the housing. Thus, if necessary, different drive parameters (e.g., amplitude, frequency) can be set for these scraping devices, with which these scraping devices are each moved back and forth about the pivot axis in a "rocking motion." This is possible because the individual drive means are arranged on a longitudinal side edge of the housing and are assigned to a respective scraping device. Thus, with the aid of the connecting elements, a simple operative connection with the assigned scraping devices can be achieved over a short distance.

[0012] In an advantageous development of the invention, a scraping device of a respective precipitation field—viewed in a plane orthogonal to the longitudinal extent of the housing—can extend along the bottom region of the housing at an angle between 110° and 130°. This means that the scraping device runs with its lower edge parallel to or along the round inner circumferential surface of the cylindrical housing at this angle. This angle can preferably be 120°. This ensures that dust particles that have settled in the bottom region of the housing in its lower half-cylinder are captured by the scraping device over a large area or across a wide area during its "rocking motion" around the pivot axis.

[0013] The drive means with which a scraping device of a respective electric precipitation field is set into a "rocking motion" around the pivot axis in the dust separator according to the invention can be designed as: linearly actuated 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 case that a connecting element for realizing an operative connection with the scraping device is designed in the form of a cable.

[0014] A mechanically simple yet robust design of a connecting element, through which the drive means are operatively connected to a scraper device, can be realized, for example, by a coupling rod. By means of such a coupling rod, a linear actuating force—that is, alternating tensile and compressive forces running tangentially to the housing circumference—is exerted on a scraper device, thereby achieving a desired "rocking motion" of the scraper device around the pivot axis running in the longitudinal direction of the housing.

[0015] In an advantageous development of the invention, the aforementioned coupling rod can be provided with an articulated connection to the scraper device. Optionally, the opposite end of the coupling rod, which faces the drive means, can also be articulated to these drive means. In any case, these articulated connections for the coupling rod effectively prevent potential distortions, tilts, or the like that could otherwise be generated for the coupling rod upon actuation of the drive means and the resulting linear actuating force.

[0016] In an advantageous development of the invention, the coupling rod can be constructed in several parts, and these parts of the coupling rod are connected to each other via a pivot joint. This also ensures that potential tension in the coupling rod cannot occur or even arise when the drive means are actuated.

[0017] In an advantageous development of the invention, if a connecting element is designed in the form of a coupling rod, the drive means can be movably connected to the mounting plate provided on an outer side of the housing. This mobility can be achieved by a swivel joint and / or by rubber elements that are flexible and elastic. In any case, such a movable attachment of the drive means to the mounting plate leads to the advantage that, when the drive means are actuated, compensation for possible tension or the like for the coupling rod is possible.

[0018] In an advantageous development of the invention, a connecting element, if designed as a coupling rod, can also be part of a joint mechanism through which the scraper device is operatively connected to the drive means. Such a joint mechanism can expediently comprise a pivot lever and / or a toggle lever, for example in the form of the aforementioned coupling rod. In any case, such a joint mechanism achieves the advantage of reducing the required stroke or travel of the drive means.

[0019] If the drive means are designed as hydraulic or pneumatic cylinders, an advantageous development of the invention can provide 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 scraper device is realized. This means that such a piston rod, with a sufficiently long length, is then directly connected, preferably in an articulated manner, with its free end to an edge region of an associated scraper device.

[0020] As already explained, the connecting element can also be designed as a traction cable instead of a coupling rod, which then exerts a tensile force on the scraper device from one side. Given that compressive forces cannot be exerted with such a cable, drive means, for example in the form of a cable winch or the like, particularly one that is driven by a motor, are provided on both sides of the housing, i.e., on its long sides, as seen in the direction of the housing's longitudinal extension, and are each assigned to a scraper device. In other words, in this case, a scraper device is controlled from both sides by means of traction cables in order to achieve a desired "rocking motion" for the scraper device around the pivot axis.

[0021] Embodiments of the invention are described in detail below with reference to a simplified schematic drawing. They show: Fig. 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 is a cross-sectional view through the housing of the dust separator of Fig. 1 , and Fig. 3 a simplified and enlarged end face or cross-sectional view of a longitudinal strut which is part of a scraper device of the dust collector of Fig. 1 or Fig. 2 is.

[0022] Below, with reference to the Fig. 1 bis 3 Preferred embodiments of an electrostatic dust collector 10 are explained, by which flue gas laden with dust particles can be intensively and efficiently cleaned. Identical features in the drawings are provided with the same reference numerals. It is specifically noted at this point that the drawing is merely simplified and, in particular, not drawn to scale.

[0023] According to the perspective view of Fig. 1 The dust separator 10 comprises a cylindrical housing 12, on the end faces of which an inlet region 30 and an outlet region 40 with associated openings are formed. Accordingly, flue gas can enter the housing 12 of the dust separator 10 through the inlet region 30, flow through the housing 12 along the longitudinal axis L, and then exit the housing 12 again through the outlet region 40, now intensively cleaned.

[0024] Along the longitudinal axis L of the housing 12, for the dust separator 10 according to the invention according to the embodiment of Fig. 1 A total of four electrical precipitation fields 13 are provided. Each of these precipitation fields 13 contains precipitation electrodes and spray electrodes arranged between them.

[0025] Fig. 2 shows a simplified cross-sectional view through the housing 12 of Fig. 1 . It can be seen that the collecting electrodes - designated here by "14" - are each plate-shaped and arranged vertically within the housing. Between the collecting electrodes - in the Fig. 2 For example, at a position marked "15" - spray electrodes can be arranged in a known manner.

[0026] In the perspective view of Fig. 1 the above-mentioned collecting electrodes 14 and discharge electrodes are not shown because of the cut-out part and for the purpose of simplifying this view.

[0027] In the bottom area of the housing 12, a plurality of dust discharge openings 16 (cf. Fig. 1 , Fig. 2 ) is formed. In the embodiment of Fig. 1 These dust discharge openings 16 are each designed in the form of triangles and are located, as shown in the Fig. 2 can be seen in the center M of the lower half-cylinder of the housing 12. It is understood that these dust discharge openings 16 can also have a shape other than triangular. The significance of these dust discharge openings 16 will be explained separately below.

[0028] The dust collector 10 according to the invention comprises a plurality of scraping devices 17, wherein individual scraping devices 17 are each assigned to a specific electrical precipitation field 13. In other words, each electrical precipitation field 13 has a separate scraping device 17.

[0029] The structure of a scraper device 17 is explained in detail below: A scraper device 17 comprises two side struts, each of which runs along a lateral edge of the scraper device 17 and - in adaptation to the round shape of the base area 11 of the housing 12 - is designed in the form of a circular arc. Fig. 1 These side struts in the electrostatic precipitation field 13, which directly adjoins the inlet area 30, are each designated with "S".

[0030] Furthermore, a scraping device 17 comprises a plurality of longitudinal struts 26, each of which extends in the longitudinal direction L of the housing 12 and is mounted between the side struts S. Thus, these longitudinal struts 26 are 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 scraping device 17 also comprises a plurality of auxiliary struts H (cf. Fig. 1 ), which are arranged between the side struts S and parallel thereto and are each attached to the longitudinal struts 26 at the intersection points.

[0031] Within the housing 12, a plurality of supports T are provided adjacent to the individual electrical deposition fields 13, namely a total of five. These supports T each extend in a plane orthogonal to the longitudinal axis L of the housing. Two of these supports T are each arranged adjacent to the end faces of the housing 12 (i.e., adjacent to the inlet region 30 and the outlet region 40, respectively), with the remaining three supports each separating the total of four electrical deposition fields 13 from one another.

[0032] In each of the individual supports T, a pivot bearing 19 is preferably mounted in a central region thereof. With regard to these pivot bearings 19 in the individual supports T, it is understood that they are preferably aligned exactly with one another and thus together form a pivot axis A1 (cf. Fig. 3 ). This pivot axis A 1 runs parallel to the longitudinal axis L of the housing 12.

[0033] On a side strut S of the scraper device 17, preferably on the two end sections thereof, two struts 18 are attached, which are attached with their opposite ends to the pivot bearing 19 of an associated carrier T. Thus, for the embodiment shown by Fig. 1 For each scraping device 17, a total of four struts 18 are provided, with which a scraping device 17 is suspended in the manner of a swing on the pivot bearings 19 of the associated supports T and is thus pivotable about the pivot axis A 1.

[0034] Fig. 3 shows an enlarged and simplified front or side view of a longitudinal strut 26. The drawing plane runs orthogonally to the longitudinal axis L of the housing 12.

[0035] According to the Fig. 3 a longitudinal strut 26 (shown here in thick black lines) - seen in a plane or in cross-section orthogonal to the longitudinal axis L of the housing 12 - has a first leg 27 and a second leg 28. The first leg 27 extends substantially radially in the direction of the pivot axis A 1 of the scraping device 17 or to an associated pivot bearing 19, which in Fig. 1 is symbolized by a dash-dotted line. Compared to the first leg 27, the second leg 28 is longer, wherein the second leg 28 extends from an end of the first leg 27 facing the pivot axis A 1 of the scraping device 17 away from the center M of the lower half-cylinder of the housing 12 outwards in the direction of an edge region R of a scraping device 17 and is longer than the first leg 27.

[0036] With regard to the design of a longitudinal strut 26, as just described in connection with the Fig. 3 As explained above, it is understood that all longitudinal struts 26 of a respective scraper device 17 can be designed in this way. In this context, it should also be noted that the majority of longitudinal struts 26 according to Fig. 3 a respective scraping device 17 are each arranged axially symmetrically with respect to the center M of the half-cylinder of the housing 12. This means that the individual longitudinal struts 26 are positioned with respect to this center M or on either side thereof in such a way that the first leg 27 faces the center M. The significance of this will be explained separately below.

[0037] With regard to the above configuration of a scraping device 17, it is understood that this expediently applies to all scraping devices 17 that are assigned to the individual electrical precipitation fields 13.

[0038] As already explained above, the design of Fig. 1 A total of four electrical precipitation fields 13 are formed in the housing 12, with separate precipitation electrodes 14, spray electrodes, and scraping devices 17 being provided for each precipitation field. Each scraping device 17 of an individual precipitation field 13 is assigned separate drive means 20, with which a scraping device 17 can be driven in the manner of a swing, in order to achieve a pivoting or rocking movement about the pivot axis A1 for the individual scraping devices 17.

[0039] Further details regarding the drive means 20 are explained below.

[0040] On an outer side of the housing 12, namely on a longitudinal side edge thereof (in Fig. 2 A mounting plate P is attached to the drive means 20 (designated "I"), to which the drive means 20 are connected. As already explained elsewhere, these drive means 20 can be designed as hydraulic cylinders or pneumatic cylinders, or in the form of a linear or spindle drive, preferably electrically driven. In any case, such drive means 20 generate a linear actuating force, which is transmitted to the scraper device 17 by means of at least one associated connecting element 22. As a result, a torque about the pivot axis A1 is transmitted from the drive means 20 to an associated scraper device 17, which is thus set into a rocking motion about the pivot axis A1.

[0041] According to the presentation of Fig. 2 A connecting element 22, with which an operative connection between the drive means 20 and a scraping device 17 is realized, can be designed in the form of a coupling rod. It is important here that an opening 24 is formed in the wall of the housing 12 adjacent to the point at which the fastening plate P is attached to the outside of the housing 12, through which opening the coupling rod 22 (or a piston rod of a hydraulic or pneumatic cylinder) extends. This makes it possible for the drive means 20 per se to be arranged entirely outside the housing 12, which leads to the advantages already mentioned above.

[0042] A coupling rod 22 can be connected in an articulated manner to a respective associated scraping device 17, preferably at an edge region R thereof (cf. Fig. 1 ) and at an end section of a longitudinal strut 26.

[0043] If the drive means 20 are designed as hydraulic cylinders, they can be mounted on the outside of the housing 12 in such a way that one end face of such a hydraulic cylinder rests against an opening 24 formed in the wall of the housing 12 and seals appropriately with the edge of this opening 24. The piston rod of such a hydraulic cylinder is then guided through the opening 24 and aligned toward the edge region R of an adjacent scraper device 17. Thus, the hydraulic seal of the piston of the hydraulic cylinder simultaneously achieves a gas-tight seal of the housing 12 at the point where the hydraulic cylinder 20 is mounted on the outside of the housing 12 in the region of an opening 24.

[0044] In the presentation of Fig. 1 The respective arrows "20" symbolize that each individual scraper device 17 is driven by two drive means 20, for example, in the form of a hydraulic cylinder. For this case, an associated coupling rod 22 is attached to a piston rod of a hydraulic cylinder, which is then preferably articulated to an end section of a longitudinal strut 26 of this scraper device 17.

[0045] With regard to a mounting plate P, to which the respective drive means 20 are attached on an outer side of the housing 12, it is specifically noted at this point that this can be a continuous plate that runs along an outer wall of the housing 12 along its longitudinal extent. Alternatively, it is possible, for example, to provide a separate mounting plate P on the outer side of the housing 12 for each individual hydraulic cylinder, which advantageously allows for material savings.

[0046] With regard to the drive means 20, it should be emphasized that these can be movably attached to the fastening plate P, for example by means of a joint with an axis of rotation A 2 (cf. Fig. 2 ), which runs parallel to the longitudinal axis L of the housing 12.

[0047] 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 is established between a cable winch and an edge region R (cf. Fig. 1 ) of an associated scraper device 17. In this case, a cable, in the same way as a coupling rod, is guided 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 scraper device 17 located inside the housing 12. In this context, it should be noted 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 (in Fig. 2 designated "I" and "II").

[0048] Irrespective of the design of the drive means 20, it can be provided for the dust separator 10 according to the invention that a scraping device 17 of a respective electric precipitation field 13 is driven by at least two such drive means 20 about the pivot axis A 1, in accordance with the arrows "20" with which in Fig. 1 the respective positions of these drive means 20 are symbolized. Deviating from this, it is also possible to provide either only one drive means 20, which is then operatively connected to an edge region R of an associated scraping device 17, preferably in its center, or to provide three or more such drive means 20 per scraping device 17.

[0049] 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, wherein the cables assigned to the individual cable winches are then attached to the opposite edge regions R of a scraper device 17.

[0050] The invention functions as follows: During operation of the dust separator 10 according to the invention, flue gas laden 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 generally results in dust and / or dirt particles, which have initially deposited on the precipitation electrodes 14, falling downwards onto the bottom area 11 of the lower half-cylinder of the housing 12 when knocked down and accumulating there.

[0051] In order to efficiently discharge fractions of dust and / or dirt from the floor area 11 of the housing 12 to the outside, the drive means 20 of the individual scraping devices 17 are actuated and thereby the scraping devices 17 are moved back and forth about the pivot axis A 1, in the manner of a rocking movement.

[0052] The above-mentioned rocking movement, which occurs for a respective scraping device 17, is illustrated by the illustration of Fig. 3 explained. Here, a longitudinal strut 26, which, as explained, is part of such a scraping device 17, is shown in solid lines at a first point in time when it has been moved by the drive means 20 in the direction of the center M of the lower half-cylinder of the housing 12. Starting from this, the scraping device 17 is then moved away from the center M, so that the shown longitudinal strut 26 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 collected on the floor area 11, whereby the dust and / or dirt particles then slide over the slope of the second leg 28 and fall down again in front of the first leg 27. When initiating an opposite movement, i.e. when the Fig. 3 When the longitudinal strut 26 shown is moved back from the position symbolized by dashed lines to the position shown by solid lines, the first leg 27 then fulfills the function of a slider, with which dust and / or dirt particles are conveyed along the floor area 11 in the direction of the dust discharge openings 16. By a cyclical sequence of such a back and forth movement of a scraping 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.

[0053] Regarding the above-explained back-and-forth movement, which is set for a scraper device 17 during its "rocking movement" around the pivot axis A1, Fig. 3 a distance a is shown, which can correspond to an amplitude of a scraper device 17 during its rocking movement. In connection with the control of a scraper device 17 by the drive means 20, this distance a corresponds to a working stroke (for example of a linear actuating cylinder in the form of a hydraulic or pneumatic cylinder), which during a movement of a scraper device 17 between the two in Fig. 3 shown positions is exerted by the drive means 20. This applies equally if the drive means 20 are designed, for example, in the form of hydraulic cylinders or alternatively in the form of cable winches.

[0054] The cross-sectional view of Fig. 2 illustrates a diameter D of the housing 12. In this regard, it should be noted that the drive means 20 can be designed in such a way that the linear actuating force generated thereby or its working stroke, which according to the illustration of Fig. 3 the distance a, for example, 5 - 10%, preferably 6 - 9%, of the diameter D of the housing 12. It is noted that the working stroke of the drive means 10, in accordance with the Fig. 3 shown distance a, can assume either exactly the stated limit values, ie the values 5, 10, 6 or 9% of the housing diameter D, or any values between these limit values.

[0055] Analogous to the various positions that are in the Fig. 3 by a longitudinal strut 26 or by an associated scraping device 17 during their rocking movement, are also shown in the Fig. 2 For a scraping device 17, a total of three discrete positions for the struts 18 are shown, with which a scraping device 17 is pivotally connected to a pivot bearing 19, as explained.

[0056] As well as through the Fig. 2 and 3As illustrated, the pivot angle with which a scraping device 17 is moved about the pivot axis A1 when controlled by the drive means 20 can be approximately 7-10°. This can correspond to the above-mentioned condition, 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.

[0057] By means 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 achieve a further reduction of the working stroke of the drive means 20, while maintaining the same amplitude for a respective scraping device 17.

[0058] Regarding 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 need to be interrupted for the described removal of dust and / or dirt particles from the housing 12 by means of the scraping devices 17. In other words, the present invention effectively ensures the continuous removal of dust and / or dirt particles during ongoing operation of the dust separator 10.

[0059] According to a further embodiment of the invention (not shown), it is possible for more than four electric precipitation fields 13 to be provided in the housing 12 of the dust collector 10, for example, five, six, or even more such electric precipitation fields. This achieves a further improved cleaning of the flue gas within the housing 12.

[0060] Finally, it should be pointed out again that the individual scraping devices 17, which are assigned to the respective electrical precipitation fields 13, can be driven independently of one another about the pivot axis A1 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, different sized fractions of dust and / or dirt are deposited on the floor area 11 of the housing 12. List of reference symbols

[0061] 10 Dust separator 11 Bottom area (of the dust separator 10) 12 Housing 13 Electric precipitation field 14 Precipitation electrode(s) 15 Position for attaching a spray electrode 16 Dust discharge opening 17 Scraper device 18 Strut(s) 19 Pivot bearing 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 scraper device 17) 27 First leg 28 Second leg 30 Inlet area (of the housing 12) 40 Outlet area (of the housing 12) A 1 Pivot axis A 2 Rotation axis D Diameter (of the housing 12) H Auxiliary strut(s) (of the scraper device 17) L Longitudinal axis (of the housing 12) MCenter (of the lower half cylinder of the housing 12) PFastening plate RRide area (of a scraper device 17) SSide strut(s) (of the scraper device 17) TCarrier aWorking stroke or travel

Claims

1. Electrostatic dust separator (10) for a horizontal throughput of gas, comprising a cylindrical housing (12) which is arranged to be horizontal and along the length dimension of which flue gas can flow, wherein provided within the housing (12) is at least one precipitation field (13) with, in particular, plate-shaped precipitation electrodes (14) and emission electrodes arranged therebetween, at least one dust discharge opening (16) formed in the base region of the housing (12), at least one scraping device (17) arranged in the lower half cylinder of the housing (12) and adjacent to the inner circumferential surface of the housing (12), wherein the scraping device (17) is mounted to be rotatable about a pivot axis (A1) extending in longitudinal direction of the housing (12), and drive means (20) by which the scraping device (17) is pivotable back and forth about the pivot axis (A1) in such a way that when pivotation of the scraping device (17) about the pivot axis (A1) takes place dust particles deposited in the base region of the housing (12) are detached by the scraping device (17) and can thereby be successively introduced into the dust discharge opening (16), characterised in that the drive means (20) are arranged outside the housing (12) and operatively connected with the scraping device (17) by way of at least one associated connecting element (22) and the drive means (20) have such a configuration that a linear setting force transmissible to the scraping device (17) can be produced by the drive means, wherein the direction of this linear setting force extends tangentially to the housing circumference.

2. Dust separator (10) according to claim 1, characterised in that a plurality of electric precipitation fields (13) is formed in the housing (12), wherein respective separate precipitation electrodes (14), emission electrodes and scraping devices (17) are provided per precipitation field (13) and wherein respective separate drive means (20) are associated with each scraping device 17) of an individual precipitation field (13).

3. Dust separator (10) according to claim 2, characterised in that at least four or more than four precipitation fields (13) are formed in the housing (12).

4. Dust separator (10) according to any one of the preceding claims, characterised in that provided at an outer side of the housing (12) is a fastening plate (P) to which the drive means (20) are attached, in particular to be movable.

5. Dust separator (10) according to claim 4, characterised in that the drive means (20) are mounted on the fastening plate (P) by means of an axis (A2) of rotation, wherein the axis (A2) of rotation extends parallelly to the longitudinal axis of the housing (12).

6. Dust separator (10) according to claim 4, characterised in that the drive means (20) are mounted on the fastening plate (P) by means of a resilient rubber bearing or the like.

7. Dust separator (10) according to any one of the preceding claims, characterised in that the drive means (20) are configured in the form of a linearly actuable setting cylinder, particularly as a pneumatic cylinder or hydraulic cylinder, or in the form of an electric linear drive or an electric spindle drive.

8. Dust separator (10) according to claim 7, characterised in that the drive means (20) are configured in the form of a setting cylinder or an electric linear or spindle drive in such a way that the drive means have for the thereby-produced linear setting force a working stroke or setting travel (s) corresponding with 6% to 9% of the diameter (D) of the housing (12).

9. Dust separator (10) according to any one of the preceding claims, characterised in that the connecting element (22) is configured in the form of a coupling rod or the like, preferably in that the coupling rod is pivotably connected with the scraping device (17), more preferably in that the coupling rod is of multi-part construction and the parts of the coupling rod are pivotably connected together.

10. Dust separator (10) according to claim 9, characterised in that the coupling rod is part of a joint mechanism by which the scraping device (17) is operatively connected with the drive means (20), preferably in that the joint mechanism comprises a pivot lever and / or an elbow lever.

11. Dust separator (10) according to any one of claims 1 to 8, characterised in that the connecting element (22) is configured in the form of a cable, wherein drive means (20) as seen in the longitudinal direction of the housing (12) are provided on both sides of the scraping device (17) so that the scraping device (17) is movable back and forth about the pivot axis (A1) per cable pull.

12. Dust separator (10) according to any one of the preceding claims, characterised in that respective struts (18) are mounted at a side edge of a scraping device (17) of a respective precipitation field (13), wherein the struts (18) are mounted by the opposite ends thereof on a rotary bearing (19) through which the pivot axis (A1) extends.

13. Dust separator (10) according to claim 12, characterised in that two respective struts (18) are provided per side edge of a scraping device (17) of a respective precipitation field (13) so that each scraping device (17) is pivotably suspended at the rotary bearing (19) by four struts (18) in total.

14. Dust separator (10) according to any one of the preceding claims, characterised in that a scraping device (17) of each precipitation field (13) as seen in a plane orthogonal to the length dimension of the housing (12) extends along the base region (11) of the housing (12) by an angle having a value between 110° and 130°, preferably an angle of 120°.

15. Dust separator (10) according to any one of the preceding claims, characterised in that a scraping device (17) of a respective precipitation field (13) has a plurality of longitudinal struts (26) which each extend in longitudinal direction (L) of the housing (12) and are arranged to be 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 extending in the plane orthogonal to the longitudinal axis (L) of the housing (12) comprises a respective first limb (27) and second limb (28), wherein the first limb (27) extends substantially radially in the direction of the pivot axis (A1) of the scraping device (17) and the second limb (28) extends from an end, which faces the pivot axis (A1) of the scraping device (17), of the first limb (27) outwardly away from the centre (M) of the housing (12) and in that case is formed to be longer than the first limb (27).

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