EP3552711A1 - Electrostatic filter unit and ventilation device with electrostatic filter unit - Google Patents

Abstract

The present invention relates to an electrostatic filter unit for a ventilation device (5) comprising an ionisation unit (2) and a separating unit (3) with at least one separating electrode (31). The electrostatic filter unit is characterized in that the separation unit (3) has a holding device (30) for holding the at least one deposition electrode (31), that the holding device (30) has a guide geometry for the at least one deposition electrode (31) and that the holding device (30) consists of electrically conductive material. In addition, the invention relates to a ventilation device (5), which has at least one such filter unit.

Description

The present invention relates to an electrostatic filter unit and a ventilation device with such a filter unit

In ventilation devices, it is known to filter out impurities from the air. In this case, mechanical filters may be used, such as nonwoven mats, porous foam media, expanded metal filter or perforated metal sheet filter. In ventilation devices, which are extractor hoods that are operated in a kitchen, while liquid and solid contaminants are filtered out of the resulting during cooking fumes and vapors. In particular, expanded metal filters, perforated plate filters, baffle filters, which can also be referred to as eddy current filters, edge suction filters and porous foam media are used as mechanical filters.

In addition, for example, from the DE 2146288 A an extractor hood is known in which an electrostatic filter is used. The electrostatic filter consists in this extractor hood plate-shaped deposition and counter electrodes and wire-shaped ionization. The plate-shaped deposition electrodes are connected to one another via electrically conductive webs, and the counterelectrodes are connected to one another via electrically conductive webs. The deposition and counterelectrodes are arranged so that the air entering the filter first flows into the deposition electrodes with wire-shaped ionization elements lying therebetween and then reaches the counter electrodes which are offset upwards. The deposition electrodes and counterelectrodes are attached to the housing of the extractor hood via partitions that are perpendicular to the electrodes and parallel to one another. The deposition electrodes and counterelectrodes alternately engage each other like a comb. In addition, a high-voltage device is provided in the housing of the hood, which is connected to the electrodes of the filter.

A disadvantage of this electrostatic filter is the large number of parts and the complex structure of the filter. In addition, the correct arrangement and isolation of the electrodes are complex against each other.

The present invention is therefore based on the object to provide a solution in which a simple construction and easy installation of an electrostatic filter unit is possible and the electrostatic filter unit can still be operated reliably.

The invention is based on the finding that this object can be achieved by using a holding device which serves to hold the deposition electrode (s) of a separation unit of the electrostatic filter unit and which at the same time functions as a counterelectrode.

According to a first aspect, the object is achieved by an electrostatic filter unit for a ventilation device. The filter unit comprises an ionization unit and a separation unit with at least one deposition electrode. The filter unit is characterized in that the separation unit has a holding device for holding the at least one deposition electrode, that the holding device has a guide geometry for the at least one deposition electrode and that the holding device consists of electrically conductive material.

As ventilation device, a device is referred to, can be sucked through the air from a room and cleaned. The ventilation device may represent a fume extraction device, for example in a kitchen. However, the ventilation device may for example also represent a wall box or a ceiling ventilation. The air flow can be caused by a blower of the ventilation device.

The electrostatic filter unit serves to filter out impurities from the air conveyed through the ventilation device. The electrostatic filter unit according to the invention has an ionization unit and a separation unit. The separation unit is connected downstream in the flow direction of the ionization unit. The Separation unit may also be referred to as a separation region or separation stage and the ionization unit as an ionization region or ionization stage.

The ionization unit preferably has at least one ionization element and at least one counterelectrode. The ionization element is subjected to voltage, preferably high voltage. As it flows through the ionization unit of contaminated air, solid and liquid substances are charged electrostatically by means of the ionization element, which can also be referred to as a spray electrode.

The separation unit comprises at least one deposition electrode. In addition, the deposition unit comprises at least one counter electrode. The counter electrode is formed according to the invention by the holding device. Due to the electric field generated by the deposition electrode and the counter electrode, the impurities charged in the ionization unit settle on the surface of the deposition electrodes and counter electrodes of the deposition unit, which can collectively be called precipitation electrodes, and are thus filtered out of the air.

The filter unit is also referred to as a filter module. The filter unit preferably represents a removable from the ventilation device, portable filter unit, which is preferably pre-assembled. As a pre-assembled filter unit is referred to, which can be used as a structural unit in the ventilation device and removed from this in a unit. The separation unit and the ionization unit can be accommodated, for example, in a common housing.

The front of the filter unit is the side through which air enters the ionization unit. The rear side is the side on which the separation unit is formed and exits via the air from the filter unit. The filter unit is thus flowed through in the flow direction from the front to the back.

In the case of the electrostatic filter unit according to the invention, which is also referred to below as a filter unit, the separating unit has a holding device for holding the at least one separating electrode on the holding device. The Holding device can also be referred to as a holding frame or frame. The holding device has a guide geometry for the at least one deposition electrode. As guide geometry, a geometry on the holding device is referred to, which guides the deposition electrode during insertion into the holding device and holds in the inserted state. The guide geometry may consist of one or more slots, grooves and / or edges.

According to the invention, the holding device consists of an electrically conductive material. As the electrically conducting material is a solid material is referred to in particular, having an electrical conductivity, which is preferably at 25 ° C> 10 ⁶ S / m. In particular, metals or conductive plastic can be used as electrically conductive material. In this case, plastic is referred to as conductive plastic, which is an intrinsically conductive polymer or is a polymer provided with conductive fillers. For example, aluminum may be used as the metal for the holding device.

The holding device with the deposition electrodes or is preferably accommodated in a housing made of non-conductive material. This housing has an inlet opening and an outlet opening, wherein the ionization unit lies in the flow direction behind the inlet opening and the outlet opening in the flow direction downstream of the separation unit. In addition, in the filter unit according to the invention, as will be explained in more detail later, at least the deposition electrode (s) and / or the holding device is at least partially insulated. In particular, the deposition electrode (s) and / or the holding device are at least in the contact areas in which they abut each other isolated.

By the holding device consists of an electrically conductive material, this can act as a counter electrode of the separation unit. In particular, the holding device can be connected to the earth of a high voltage unit and thus form the counter electrode to the at least one deposition electrode of the separation unit. The holding device thus fulfills two functions in the filter unit according to the invention. On the one hand, the separating electrode (s) are received or held and aligned by this, and on the other hand, the holding device serves as a counter electrode. As a result, a number of advantages can be achieved.

In particular, the structure of the filter unit is simplified, since only the deposition electrode (s) has to be attached to the holding device or must be introduced into it. By also providing a guide geometry to the holding device, the assembly of the filter unit is simplified. In addition, separate guide elements are not necessarily required, so that this way the number of parts is reduced. Furthermore, only one contact point is required for connecting the holding device as a counter electrode to the earth of a high voltage unit.

According to a preferred embodiment, the holding device comprises a first and a second boundary wall and at least two frame webs lying between the first and second boundary wall. The frame webs are fixedly connected to the boundary walls and are preferably designed in one piece with the boundary walls. Between two adjacent frame webs in each case a receiving space for at least part of a deposition electrode is formed in the holding device. In addition, in this embodiment, the guide geometry preferably comprises at least one passage slot for a deposition electrode through one of the boundary walls. The one or more passage slots represent elongated slots.

The holding device preferably has a rectangular box shape, which is open to the front and back. As the front side of this case, the side of the holding device is referred to, which faces the ionization unit. The rear side is the side of the holding device facing away from the ionization unit. The first and the second boundary wall are preferably parallel to each other. The first boundary wall can be, for example, the upper side of the holding device and the second boundary wall the underside of the holding device. However, it is also within the scope of the invention that a side wall of the holding device forms the first and the opposite side wall, the second boundary wall. However, the first and second boundary wall are always opposite each other on the holding device. The holding device comprises at least two frame webs. These frame webs are located between the first and the second boundary wall. The frame webs are aligned so that they extend between the front and the back of the holding device. Particularly preferably, the frame webs are perpendicular to the front or the back of the holding device. Since the holding device is traversed by air in this direction, the obstruction is low in the alignment of the frame webs in this direction. The frame webs may be disposed at the ends of the first and second boundary walls. Preferably, however, at least one frame web is also arranged between the lateral ends of the first and second boundary wall. Particularly preferably, the holding device has a plurality of frame webs. Depending on the size of the holding device, for example, more than ten or even more than twenty frame webs may be provided.

Between two adjacent frame webs, a receiving space for at least a part of a deposition electrode is preferably formed in each case. As a result, the deposition electrodes and the frame webs of the holding device are present alternately in the separation unit.

Preferably, the guide geometry comprises at least one passage slot for a deposition electrode through one of the boundary walls. The passage slot may also be referred to as a passage slot. By providing at least one passage slot, it is possible to bring the at least one deposition electrode into the region between the boundary walls and in particular into a receiving space. The passage slot is in this case dimensioned such that its surface corresponds to the cross section of the deposition electrode. As a result, the deposition electrode is guided through the passage slot on the one hand during insertion. On the other hand, the deposition electrode is held in position after insertion but also through the passage slot.

Preferably, a plurality of passage slots are provided in a boundary wall and the passage slots are parallel to each other.

According to a preferred embodiment, the frame webs extend perpendicular to the first and second boundary wall of the holding device and lie parallel to each other. Particularly preferably, the at least one passage slot of the guide geometry is introduced in each case between two frame webs in one of the boundary walls. Particularly preferably, the passage slot is inserted centrally between two frame webs. The passage slot is parallel to it the cross section of the frame webs. Due to the central arrangement, a centering of the introduced through the passage slot deposition electrode between the frame webs is achieved. In particular, flexible separating electrodes can also be used, which are then aligned as centrally as possible between the fixed frame webs. Since the frame webs act as part of the holding device as a counter electrode, thereby a secure construction of the electric field is ensured and a strike-through or short circuit can be prevented due to the uniform distance.

According to a preferred embodiment, in the first boundary wall at least one passage slot and in the second boundary wall, also at least one passage slot is introduced, which is aligned with the at least one passage slot in the first boundary wall. Preferably, also in this embodiment, a plurality of passage slots are introduced in the first boundary wall and the number of passage slots in the first boundary wall corresponds to the number of passage slots in the second boundary wall. The passage slots in the boundary walls lie exactly above each other within the processing tolerances. Since the holding device preferably constitutes a positive web-frame construction consisting of the boundary walls and the frame webs, a force necessary for pre-stressing a flexible separation electrode to be introduced into the holding device can be securely absorbed by the holding device, so that a deformation the frame is avoided by the bias.

Moreover, by aligning the passage slots with each other, the separation electrode can be inserted into the accommodation space through the passage slot in the first boundary wall and out of the accommodation space through the passage slot in the second boundary wall, or vice versa. In this embodiment, therefore, the deposition electrode preferably has a length which is greater than the distance between the first and the second boundary wall. As a result, in addition to the abutment against the passage slots, the deposition electrode can also be located at a location outside the receiving space, for example the upper side of the first boundary wall or Bottom of the second boundary wall to be fixed. Thus, the holder of the deposition electrode is further improved.

According to a preferred embodiment, in this case the edges of the at least one passage slot are rounded. By rounding off the edges, the deposition electrode can be deflected by a radius of curvature that corresponds to the rounding and abut the rounded edge. Damage to the deposition electrode or a coating of the deposition electrode can be prevented thereby.

According to a preferred embodiment, the deposition electrode is formed by a band which extends through at least two receiving spaces of the holding device perpendicular to the first and second boundary wall. In this case, the band is preferably guided through passage slots in the boundary walls. This embodiment has the advantage that the number of contacting points required for contacting the collecting electrodes with the high voltage unit is limited to two. In particular, only the holding device must be connected as a counter electrode to the ground of the high voltage unit and the band-shaped Abscheideelektrode must be connected to the positive terminal of the high voltage unit.

The band-shaped deposition electrode can be threaded through the through slots of the holding device and pulled tightly according to an embodiment. In this case, the deposition electrode is first guided through a first passage slot of the first boundary wall, then through the thus aligned first passage slot of the second boundary wall. Thus, a portion of the length of the deposition electrode extends perpendicular to the boundary walls and is preferably located centrally between two adjacent frame lands. Subsequently, the deposition electrode is bent over and inserted into the through-slot of the second boundary wall adjacent to the passageway through which the deposition electrode has been led out. The deposition electrode is then inserted from inside into a passageway of the first boundary wall, which leads to the first through slot is adjacent. This threading is carried out until the deposition electrode passes through each of the passage slots in the boundary walls. The one end of the band-shaped deposition electrode can be fixed, for example, at the top of the first boundary wall, for example, be clamped. The other end of the band-shaped deposition electrode is then led to a contact point, which may be provided in the holding device or on an outer side of the holding device and via which the separation electrode can be connected to the high-voltage unit.

As an alternative to threading a band-shaped deposition electrode, the deposition electrode may be a preformed component having a meandering shape. In this embodiment, the holding device is preferably designed so that the passage slots extend to the front or the back of the respective boundary wall. Thus, the through-slots are open to one side in this embodiment. From the open side, the preformed meander-shaped deposition electrode can be introduced into the holding device, that is to be inserted. Subsequently, the passage slots can be closed, for example, by a strut or a cover frame. The length of the individual meander arms in this embodiment is therefore so long that it corresponds to the distance between the top of the first boundary wall and the bottom of the second boundary wall. The distance between the meander arms corresponds to the distance between adjacent passage slots in one of the boundary walls. By this embodiment, the effort in the production of the separation unit is further minimized.

According to an alternative embodiment to the embodiment in which through-slots are provided in both boundary walls, at least one passage slot is introduced in the first boundary wall and at least one guide groove is introduced in the second boundary wall, which is aligned with the passage slot of the first boundary wall. This embodiment has the advantage that a plate-shaped deposition electrode can be introduced through the passage slot of a boundary wall and with a Edge out into the guide groove of the other boundary wall and can be held there. Preferably, only guide slots are provided in this embodiment in the one boundary wall and only guide grooves in the other boundary wall. As a result, the deposition electrodes to be introduced into the holding device can be introduced and contacted from one side, namely the boundary wall, in which the passage slots are provided.

Preferably, the at least one deposition electrode in this embodiment is a flat plate and in each receiving space, a deposition electrode is at least partially accommodated.

In order to prevent a short circuit between the deposition electrode (s) and the holding device, insulation according to the invention is preferably provided between the collecting electrodes, that is to say the separating electrodes and the holding device.

According to one embodiment, the at least one deposition electrode is insulated over its entire surface except for a contact region for contacting the high-voltage unit. The insulation can be produced by a coating with an insulating material, which is also referred to as insulator. The contact region for contacting with the high-voltage unit is preferably recessed by such a coating. However, it is also possible that the at least one deposition electrode is also provided with insulation in the contact region for contacting the high-voltage unit, and the contacting is effected by means which passes through the insulation.

Alternatively or additionally, the holding device can also be insulated. Also in this case the insulation can be produced by a coating. In an insulated holding device, the isolation of the at least one deposition electrode is no longer mandatory and vice versa.

According to one embodiment, the at least one deposition electrode has, as a contact region, a contact projection which projects outward beyond the boundary wall in which the at least one passage slot is made. The contact projection may, for example, be a contact nose on an edge of a plate-shaped deposition electrode. After all plate-shaped deposition electrodes are introduced into the holding device, they can be connected to the high-voltage unit via a single contact element, for example a rail, which extends along the protruding contact projections. The individual contacting of the deposition electrodes is therefore no longer necessary.

According to one embodiment, the at least one passage slot terminates at the holding device at a distance to the front and back of the holding device. The at least one deposition electrode preferably has a cross-section corresponding to the area of the passage slot. By the passage slot is limited to the front and to the rear by the material of the boundary wall into which it is introduced, a displacement or even falling out of the deposition electrode can be prevented.

The holding device can be produced as an integral part, that is to say in one piece. In this case, preferably in the manufacture of the holding device except the boundary walls and the frame webs and the guide geometry is formed. The holding device can be produced for example by injection molding. This production method has the advantage that the contours of the holding device, in particular the boundary walls with through slot and / or guide groove and the frame webs can be generated in the production in a simple manner. A subsequent formation of the guide geometry, for example, a subsequent introduction of passage slots or guide grooves is not required.

As an alternative to the one-part embodiment, the holding device can also be constructed in two parts, one part comprising the boundary walls with the introduced guide geometry and another part representing a cover frame which closes the guide geometry to the front or to the rear. The first part points preferably also the frame webs. The passage slots extend in this embodiment to the front or back of the first part. In this way, a preformed deposition electrode, which in particular has a meandering shape, can be inserted over the open side of the passage slots. After the introduction of the deposition electrode, the cover frame can then be applied to the side of the first part, thereby closing the passage slots. The cover frame may consist of one or more parts. For example, the cover frame may consist of two struts, which are each attached to the side of the respective boundary wall. But it is also possible that the cover frame is designed in one piece, wherein said struts are connected to each other via connecting webs at the edge.

According to one embodiment, in each case a plate-shaped extension is arranged on the holding device at the front side of the first and the second boundary wall, each extension extending into the ionization unit and forming the counterelectrodes of the ionization unit. The plate-shaped extensions preferably extend in the surface direction of the respective boundary wall. Thus, the extensions lie parallel to each other. This embodiment has the advantage that the overall structure of the filter unit is further simplified. Preferably, the extensions are integrally formed with the boundary wall. This is possible in a simple manner, in particular in the production of the holding device by an injection molding process. A separate contacting of the counter electrodes of the ionization unit, in particular connection to the ground of the high voltage unit is no longer necessary in this embodiment, since the holding device is already connected to the earth as a counter electrode of the separation unit.

According to a further embodiment, the holding device has at a lateral edge of the boundary walls a contact space for contacting the at least one deposition electrode, which consists of a non-conductive material.

According to a further aspect, the invention relates to a ventilation device comprising at least one electrostatic filter unit according to the invention.

Advantages and features that are described with regard to the electrostatic filter unit also apply - as far as applicable - to the ventilation unit and vice versa.

The electrostatic filter unit may be arranged on the ventilation device, preferably in the suction opening. Alternatively, the electrostatic filter unit can also be installed in the flow direction downstream of the suction opening of the ventilation device. The electrostatic filter unit is installed in the ventilation device so that inflowing air first flows through the ionization unit before it reaches the separation unit.

• Figur 1: eine schematische Perspektivansicht einer Ausführungsform der erfindungsgemäßen Lüftungsvorrichtung;
• Figur 2: eine schematische Perspektivansicht einer ersten Ausführungsform einer Haltevorrichtung der erfindungsgemäßen elektrostatischen Filtereinheit;
• Figur 3: eine schematische Schnittansicht der Ausführungsform der Haltevorrichtung nach Figur 2;
• Figur 4: eine schematische Perspektivansicht der Ausführungsform der Haltevorrichtung nach Figur 2 mit Abscheideelektrode;
• Figur 5: eine schematische Detailansicht eines Teils der Haltevorrichtung und der Abscheideelektrode nach Figur 4;
• Figur 6: eine schematische Perspektivansicht einer zweiten Ausführungsform einer Haltevorrichtung der erfindungsgemäßen elektrostatischen Filtereinheit mit Abscheideelektroden; und
• Figur 7: eine schematische Schnittansicht der Ausführungsform der Haltevorrichtung mit Abscheideelektroden nach Figur 6.

The invention will be described again below with reference to the accompanying figures. Show it:

• FIG. 1 a schematic perspective view of an embodiment of the ventilation device according to the invention;
• FIG. 2 a schematic perspective view of a first embodiment of a holding device of the electrostatic filter unit according to the invention;
• FIG. 3 a schematic sectional view of the embodiment of the holding device according to FIG. 2 ;
• FIG. 4 : A schematic perspective view of the embodiment of the holding device according to FIG. 2 with deposition electrode;
• FIG. 5 : A schematic detail view of a part of the holding device and the deposition electrode according to FIG. 4 ;
• FIG. 6 a schematic perspective view of a second embodiment of a holding device of the electrostatic filter unit according to the invention with deposition electrodes; and
• FIG. 7 : A schematic sectional view of the embodiment of the holding device with deposition electrodes according to FIG. 6 ,

In FIG. 1 an embodiment of a ventilation device 5 according to the invention is shown, which represents an extractor hood in the form of a ceiling ventilation. In the illustrated embodiment, the ventilation device 5 has a ventilation housing 50 and a baffle plate 51 located below, that is, in the flow direction in front of the underside of the ventilation housing 50. In this case, an intake opening 52 is formed between the underside of the ventilation housing 50 and the baffle plate 51, which can also be referred to as Absaugspalt. In the suction port 52 a plurality of filter units 1 are introduced. In the illustrated view, over the width of the ventilation device 5, two and over the depth of the ventilation device 5, a filter unit 1 is introduced. The ventilation device 5 is mounted above a hob 6 and can be accommodated, for example, in the ceiling (not shown), wherein at least the suction opening 52 is at least temporarily below the ceiling. Of the filter units 1 are in the FIG. 1 only the protective grid 10, are attached to the front sides of the filter units 1, to recognize.

In FIG. 2 is a perspective view of a first embodiment of the holding device 30 of the electrostatic filter unit 1 according to the invention shown. The filter unit 1 has an ionization unit 2 and a separation unit 3. From the ionization unit 2 are in the FIG. 2 only the counter electrodes 20 are shown. In addition, an ionization electrode (not shown) is provided in the ionization unit 2, which may for example be a wire extending in the width direction of the filter unit 1 parallel to the counter electrodes 20 between them.

The ionization unit 2 lies in the flow direction in front of the separation unit 3. The flow direction is indicated schematically by the arrow S in FIG. From the separation unit 3 is in FIG. 2 only the holding device 30 is shown. The holding device 30 forms in the filter unit 1 according to the invention, the counter electrode of the separation unit 3. In addition, the separation unit 3, a deposition electrode 31 (see FIG. 4 ), which will be described later in more detail.

The holding device 30 has a box shape. The side of the holding device 30 and thus of the separation unit 3, which faces the ionization unit 2, is also referred to below as the front side. The opposite side of the holding device 30 and thus the separation unit 3 is also referred to as the back. The holding device 30 is open to the front and to the rear. In particular, the holding device 30 consists of a first boundary wall 300 and a second boundary wall 301 which are parallel to one another and form the top and bottom of the holding device 30. Between the boundary walls 300, 301 extending perpendicular to the boundary walls 300, 301 standing frame webs 303. The frame webs 303 extend from the front to the back of the holding device 30 parallel to each other and have a low material thickness. Between two adjacent frame webs 303 a receiving space 302 is formed in each case. At the lateral edge of the boundary walls 300, 301, the holding device 30 in the illustrated embodiment has a side wall 307 which is parallel to the frame webs 303 but has a greater material thickness than the frame webs 303.

In the illustrated embodiment, passage slots 304 are introduced in the first boundary wall 300, which is also referred to below as the upper side of the holding device 30. The passage slots 304 extend in the depth direction of the boundary wall 300, that is, in the direction from the front side to the rear side of the holding device 30. The passage slots 304 are parallel to each other. As is clear from the FIG. 3 1, which shows a sectional view, the passage slots 304 lie in the width direction of the first boundary wall 300 in the middle between the frame bars 303.

As it turned out FIG. 3 Furthermore, in the embodiment shown, passage slots 304 are also introduced in the second boundary wall 301, which is referred to below as the underside of the holding device 30. The passage slots 304 in the lower boundary wall 301 are aligned with the passage slots 304 in the upper boundary wall 301, that is, are also located in the middle between adjacent frame bars 303th

At the back of the holding device 30, a cover 309 is provided. By the cover frame 309, a strut 308 is formed on the back of the boundary walls 300, 301. By this strut 308, the passage slots 304 are closed to the rear. The cover frame 309 may be formed integrally with the boundary walls 300, 301. In particular, the strut 308 can be formed by inserting the passage slots 304 into the upper boundary wall 300.

As it turned out FIG. 3 results, the edges of the passage slots 304 are rounded.

In the first embodiment of the holding device 30, this can also be referred to as a clamping frame for a deposition electrode 31, which represents a flat conductor, which is at least at the contact points with the holding device 30, but preferably completely isolated.

With reference to FIGS. 4 and 5 Now, the embodiment of the deposition electrode 31 which is preferably used in the first embodiment of the holding device 30 will be described. In the embodiment shown, the deposition electrode 31 constitutes a flat conductor, in particular a metal band. One end of the deposition electrode 31 rests on the upper side of the first boundary wall 300. There may be provided a locking device (not shown) or a clip (not shown) for clamping the end of the deposition electrode 31. The deposition electrode 31 is guided from this end through a first passage slot 304 of the first boundary wall 300 and thereafter extends perpendicularly through a first receiving space 302. The deposition electrode 31 extends through a first passage slot 304 of the second boundary wall 301 therethrough. At the bottom of the second boundary wall 301, the deposition electrode 31 is bent over and guided by a second passage slot 304 adjacent to the first passage slot 304 into a second reception space 302 of the holding device 30. Through this receiving space 302, the deposition electrode 31 extends parallel to the frame bars 303 and exits at the top of the receiving space 302 by the second to the first passage slot 304 adjacent through slot 304 upwards. There, the deposition electrode 31 is again bent over and inserted into the third passageway 304 of the first boundary wall 300 adjacent to the second passageway slot 304.

This course of the deposition electrode 31 continues to the side of the holding device 30 which is opposite to the side where the first end of the deposition electrode 31 lies. In the illustrated embodiment, a contact space 4 is arranged on this side of the holding device 30. This can be formed by non-conductive potting compound on the holding device 30. In the contact space 4, the second end of the deposition electrode 31 is inserted, where it can be connected to a high voltage unit (not shown).

At the support points of the deposition electrode 31 on the holding device 30, in particular on the first and second boundary wall 300, 301 between the passage slots 304, the material of the boundary wall 300, 301 is rounded. The radius of the rounding is determined in particular by the permissible bending radius of an insulation coating on the deposition electrode 31.

The introduction of the deposition electrode 31 can be done by threading the flat conductor in the manner described. In this case, preferably a guide device (not shown) can be introduced from the front or rear side into the receiving spaces 302, which fills these except for a gap through which the deposition electrode 31 is to be guided.

As an alternative to threading, it is also possible that the separation unit in the in the FIGS. 4 and 5 shown shape is preformed. In this embodiment, the holding device 30 is then preferably designed in two parts. In one of the two parts, the boundary walls 300, 301 with the passage slots 304 and the frame webs 303 are formed. The passage slots 304 are open at the first part to a longitudinal end. In these open passage slots 304, the preformed Abscheidideelektrode 31 can be inserted, for example from the back. After the deposition electrode 31 is inserted, then the second part, which can be referred to as cover frame 309, placed and closes the open ends of the passage slots 304 to the rear.

In the FIGS. 6 and 7 a second embodiment of the separation unit 3 of the filter unit 1 according to the invention is shown.

The second embodiment is different from that in FIGS FIGS. 2 to 5 shown first embodiment in that the holding device 30 has only in the first boundary wall 300 through slots 304. In addition, in the FIG. 2 no extensions 306 of the holding device 30 shown on the front, which serve as counterelectrodes of the ionization unit 2. However, the provision of such extensions 306 is possible also in the second embodiment of the holding device 30.

As in the first embodiment, the holding device 30 in the second embodiment has a box shape. The holding device 30 is open to the front and to the rear. In particular, the holding device 30 consists of a first boundary wall 300 and a second boundary wall 301 which are parallel to one another and form the top and bottom of the holding device 30. Between the boundary walls 300, 301 extending perpendicular to the boundary walls 300, 301 standing frame webs 303. The frame webs 303 extend from the front to the back of the holding device 30 parallel to each other and have a low material thickness. Between two adjacent frame webs 303 a receiving space 302 is formed in each case.

In contrast to the first embodiment, no through-slots are introduced in the second boundary wall 301 in the second embodiment. Instead, in the top, the second boundary wall 301, that is, the side of the second boundary wall 301, which faces the first boundary wall 301, guide grooves 305 are introduced. The guide grooves 305 are positioned so that they are aligned with the passageway slot 304 in the first boundary wall 300, that is, lie vertically below the passageway slot 304.

In the holding device 30, deposition electrodes 31 are inserted in the second embodiment, each representing a plate. At each of the deposition electrodes 31, a contacting projection 310 is provided at the upper edge. Each deposition electrode 31 is guided from above through a passage slot 304 in the first boundary wall 300 and extends through the accommodation space 302 inside the support device 30. The lower edge of the deposition electrode 31 is in the guide groove 305 added. The Kontaktiervorsprünge 310 over the top of the first boundary wall 300 over and can be connected to contact means, such as a rail.

Also in the second embodiment, the holding device 30 may be one-piece or two-piece. In particular, the boundary walls 300, 301 and the frame webs 303 may be formed as one part up to an end of the through slots 304 in the first boundary wall 300. At this part can then be attached as a cover frame (not shown) further part and so the passage slots 304 are limited.

In the two embodiments shown, the deposition electrodes 31 are preferably each provided with an insulating coating (not shown).

The invention will be described again generally below. A fluid to be cleaned, which in particular represents air, flows or flows through the electrostatic filter unit according to the invention, which can also be referred to as an electrostatic filter. The flow is preferably effected by a fan of a ventilation device on which the filter unit is provided. In this case, particles in the fluid are first charged electrically within an ionization unit and later deposited in a separation unit. The separation unit is characterized by the fact that it contains as homogeneous an electric field as possible. The electric field force (F) acts on the charged particles during their passage parallel to the field lines due to their charge. The resulting acceleration deflects the particles from their path and, after a discrete time t, hits the precipitating electrodes. With this impact, the particles are considered deposited. Due to the principle, the efficiency of the deposition becomes maximum when the residence time of the particles is greater than the maximum design path s.

The electrostatic filter unit according to the invention can be used for filtering particles and air contaminants down to the fine dust range of 1 μm. The filter unit according to the invention is optimized according to manufacturing aspects, costs and performance technical aspects.

The precipitation electrodes of the separation unit constitute an obstruction of the passing fluid volume flow. Due to the obstruction, the fluid velocity increases linearly to the obstruction. This is equivalent to a reduction of the residence time t. Today's electrostatic filters compensate for these losses by extending the separation unit to increase the residence time. At the same time, the pressure loss at the separation unit increases with the increase in the speed and the extension of the separation unit. The energy efficiency of the overall system is reduced by a higher lockout.

In known electrostatic filters are usually provided arrays / rows of metal plates, similar to a normal plate capacitor. The plates must be arranged isolated from each other at least at their suspension. Depending on the field of application and operating conditions, a completely flat insulation layer of the electrodes may additionally be necessary in order to avoid flashovers. The lockup increases thereby.

In addition, the design effort and the production costs are high due to the high number of parts and the complex alignment of the plates.

The present invention no longer has these disadvantages or at least reduces these disadvantages.

With the present invention, a preferably one-piece but optionally also multi-part form-locking holding device is provided, which can also be referred to as a frame or holding frame. The holding device is made of electrically conductive material and is in a separation unit in the electrostatic filter unit, which can also be referred to as an electrostatic filter module used. The frame is connected to the earth of the connected high voltage unit. The purpose of the frame is to receive and align the deposition electrodes, which may also be referred to as high voltage electrodes. The frame itself has a high mechanical stability due to a large number of form-fitting frame webs. At the same time, the frame forms the opposite pole to the high-voltage electrodes. To electrically connect frame and high voltage electrode optionally, the separation electrode can be sheathed with insulation or the frame is correspondingly coated with an insulator.

Optionally, the counter-electrodes of the necessary ionization unit may be attached to the inflow side, that is to say the front side, of the holding device. In this configuration, the installation effort of the ionization unit is further reduced. Only wire shooting and contacting the high voltage component must be created in addition to the fixture.

Preferably, the Abscheidepaket consisting of holding device and Abscheideelektrode (s) and the ionization unit are integrated in an insulated outer housing.

Since in the filter unit according to the invention, the holding device itself is connected to the ground of the high voltage source, the number of necessary components and at the same time the number of assembly steps are reduced.

In the embodiment of the filter unit, in which a single deposition electrode, in particular a positive flat conductor, is used and threaded, for example, into the holding device, the number of necessary contacts is further reduced. Apart from the power supply of the high voltage unit then only two contacts must be installed in the filter unit. The fixture must be connected to earth and the flexible precipitator electrode to the positive output of the high voltage unit. This contacting is simpler than in known filter units in which all configured as plates collecting electrodes, that is, deposition electrodes and counter electrodes, connected to each other via rails or continuous cables in series and then connected to the high voltage unit.

In the embodiment of the filter unit in which only one-sided passage slots and preferably guide grooves are provided opposite, the number of electrode plates of the separation unit is reduced by half compared to the known filter units, since the holding device with the frame struts forms the counter electrodes, but not the frame struts more individually introduced and need to be contacted. Only the deposition electrodes, which are designed as plates, must continue to be contacted in series and connected to the high-voltage power supply. The advantage of this embodiment lies in the reduced number of components for the separation unit by 50%. The introduction of the still necessary plate is unilateral and therefore manufacturing technology is easy to handle.

The positive connection of the holding device, in particular the first and second boundary wall by the frame webs also results in an enormous mechanical stability and the geometry has advantages in the production by injection molding (conductive plastics, aluminum, etc.), as reduced by the positive locking of the delay becomes.

reference numeral

1

filter unit

10

guard

2

lonisationseinheit

20

counter electrode

3

separation unit

30

holder

300

first boundary wall

301

second boundary wall

302

accommodation space

303

frame stay

304

Through slot

305

guide

306

renewal

307

Side wall

308

strut

309

Cover

31

deposition electrode

310

Kontaktiervorsprung

4

Contact space

5

breather

50

vent housing

51

flapper

52

suction

6

hob

S

flow direction

Claims (18)

Electrostatic filter unit for a ventilation device (5) comprising an ionization unit (2) and a separation unit (3) with at least one separation electrode (31), characterized in that the separation unit (3) comprises a holding device (30) for holding the at least one deposition electrode (31), that the holding device (30) has a guide geometry for the at least one deposition electrode (31) and that the holding device (30) consists of electrically conductive material. Electrostatic filter unit according to claim 1, characterized in that the holding device (30) comprises a first and a second boundary wall (300, 301) and at least two between the first and second boundary wall (300, 301) lying frame webs (303) that between two adjacent Frame webs (303) each have a receiving space (302) for at least part of a Abscheidideelektrode (31) is formed and that the guide geometry at least one passage slot (304) for a Abscheidelektrode (31) through one of the boundary walls (300, 301). Electrostatic filter unit according to claim 1 or 2, characterized in that the frame webs (303) perpendicular to the first and second boundary wall (300, 301) of the holding device (30) extend parallel to each other and that the at least one passage slot (304) of the guide geometry respectively between two frame webs (303) in one of the boundary walls (300, 301) is introduced. Electrostatic filter unit according to one of claims 1 to 3, characterized in that in the first boundary wall (300) at least one passage slot (304) and in the second boundary wall (301), also at least one passage slot (304) is introduced, with the at least a passageway (304) in the first boundary wall (300) is aligned. Electrostatic filter unit according to one of claims 2 to 4, characterized in that the edges of the at least one passage slot (304) are rounded. Electrostatic filter unit according to one of claims 2 to 5, characterized in that the deposition electrode (31) is formed by a band extending through at least two receiving spaces (302) of the holding device (30) perpendicular to the first and second boundary wall (300, 301 ). Electrostatic filter unit according to claim 6, characterized in that the deposition electrode (31) is a preformed component and has a meandering shape. Electrostatic filter unit according to one of claims 1 to 7, characterized in that in the first boundary wall (300) at least one passage slot (304) is introduced and in the second boundary wall (301) at least one guide groove (305) is introduced, with the passage slot (304) of the first boundary wall (300) is aligned. Electrostatic filter unit according to one of claims 2 to 8, characterized in that the at least one deposition electrode (31) is a flat plate and in each receiving space (302) a deposition electrode (31) is at least partially accommodated. Electrostatic filter unit according to one of Claims 1 to 9, characterized in that the at least one deposition electrode (31) is insulated over its entire surface except for a contact region for contacting with a high-voltage unit. Electrostatic filter unit according to one of claims 9 or 10, characterized in that the at least one deposition electrode (31) has as a contact region a contact projection (310) which extends over the Boundary wall (300, 301), in which the at least one passage slot (304) is introduced, protrudes outward. Electrostatic filter unit according to one of claims 1 to 11, characterized in that the holding device (30) is insulated. Electrostatic filter unit according to one of claims 1 to 12, characterized in that the at least one passage slot (304) terminates at a distance to the front and back of the holding device (30). Electrostatic filter unit according to one of claims 1 to 13, characterized in that the holding device (30) is constructed in two parts, wherein one part comprises the boundary walls (300, 301) with the introduced guide geometry and another part is a cover frame (309), the the guide geometry closes forwards or backwards. Electrostatic filter unit according to one of claims 1 to 14, characterized in that on the holding device (30) at the front of the first and the second boundary wall (300, 301) each have a plate-shaped extension (306) is arranged, each in the ionization unit (2) and which form the counterelectrodes of the ionization unit (2). Electrostatic filter unit according to one of claims 1 to 15, characterized in that the holding device (30) at a lateral edge of the boundary walls (300, 301) has a contact space (4) for contacting the at least one deposition electrode (31), which consists of a non-conductive Material exists. Electrostatic filter unit according to one of claims 1 to 16, characterized in that the holding device (30) is produced by an injection molding process. Ventilation device, characterized in that it comprises at least one electrostatic filter unit (1) according to one of claims 1 to 17.

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