EP1242188B1 - Electrostatic separator - Google Patents

Description

The invention relates to an electrostatic precipitator for deposition of liquid or solid particles from a gas stream, after the preambles of claims 1 and 12, respectively.

Such electrostatic precipitators are known from DE 198 22 332 C1. There is outside of the precipitation electrode forming tube a movement of the cleaning body effecting actuator (e.g., a thermally actuable growth element) arranged, the movement over a boom and a support arm is connected to the cleaning body. It is for the arrangement and placement of the actuating means additional Space needed, not available in many applications stands, e.g. during operation of the electrostatic precipitator on an internal combustion engine.

The object of the invention is therefore to develop an electrostatic precipitator, the cleaning of the corona forming portion of the Internal electrode allows and thereby compact and space-saving design is.

This object is achieved by the features specified in claims 1 and 12, respectively Characteristics solved.

Advantageous embodiments of the invention are in the subclaims specified.

The basic idea of the invention is, by the hollow design the inner electrode, in the section where the inner electrode has a having larger diameter, advantageously previously unused To make space available for the accommodation of used the cleaning mechanism causing components becomes.

Due to the integration of the actuating element and / or associated therewith Power transmission means in the inner electrode is a total of achieved compact and space-saving design of Elekroabscheiders. For the inventively designed electrostatic precipitator is no more space needed than for an electrostatic precipitator in the the corona area of the inner electrode is not cleaned. The attachment of additional components next to the collecting electrode forming pipe is completely eliminated or kept to a minimum.

Figur 1

einen Schnitt durch eine erste Ausführungsform des Elektroabscheiders, bei der eine den zweiten Abschnitt der Innenelektrode ausbildende Nadel zur Reinigung gegenüber einem unbeweglichen Reinigungskörper verschoben wird, wobei dieser Elektroabscheider an einem Verbrennungsmotor eingesetzt wird und in der Stellung bei laufendem Motor dargestellt ist,

Figur 2

wie Figur 1, jedoch in der Stellung bei Motorstillstand,

Figur 3

einen Schnitt durch eine zweite Ausführungsform des Elektroabscheiders, bei der der Reinigungskörper gegenüber der den ersten Abschnitt der Innenelektrode ausbildenden unbeweglichen Nadel zur Reinigung verschoben wird, wobei dieser Elektroabscheider an einem Verbrennungsmotor eingesetzt wird und in der Stellung bei laufendem Motor dargestellt ist,

Figur 4

wie Figur 3, jedoch in der Stellung bei Motorstillstand,

Figur 5

einen Schnitt durch eine dritte Ausführungsform des Elektroabscheiders,

Figur 6

eine Seitenansicht einer hohlen, geschlitzten Innenelektrode mit einem Halteelement für den Reinigungskörper,

Figur 7

einen Querschnitt durch die Niederschlagselektrode im Bereich des Reinigungskörpers und des Halteelements.

Embodiments of the invention will be explained in more detail with reference to the drawing. It shows:

FIG. 1

a section through a first embodiment of the electrostatic precipitator in which a needle forming the second portion of the inner electrode is displaced for cleaning relative to a stationary cleaning body, this electrostatic precipitator is used on an internal combustion engine and is shown in the position with the engine running,

FIG. 2

as in FIG. 1, but in the position at engine standstill,

FIG. 3

a section through a second embodiment of the electrostatic precipitator in which the cleaning body is moved relative to the immovable needle forming the first portion of the inner electrode for cleaning, this electrostatic precipitator is used on an internal combustion engine and is shown in the position with the engine running,

FIG. 4

as in FIG. 3, but in the position when the engine stops,

FIG. 5

a section through a third embodiment of the electrostatic precipitator,

FIG. 6

a side view of a hollow, slotted inner electrode with a holding element for the cleaning body,

FIG. 7

a cross section through the collecting electrode in the region of the cleaning body and the holding element.

In Figure 1 and Figure 2 are each a section through a first embodiment of the electrostatic precipitator, which is preferably connected to a Internal combustion engine used for de-oiling crankcase gases becomes. 1 shows the electrostatic precipitator in the position while the engine is running, while Figure 2 shows the electrostatic precipitator at engine standstill shows. The electrostatic precipitator consists of a tube (1), is traversed in the longitudinal direction of the gas to be cleaned, the inner wall (1A) of which is a collecting electrode for the forms particles to be separated. Center inside the tube (1) is in Extending longitudinally extending an inner electrode (2), wherein in the space between this inner electrode (2) and the collecting electrode (1A) consists of a high voltage electric field. The inner electrode (2) has a first portion (2A) on the inflow side with a small cross-sectional area and downstream a second section (2B) with a larger cross-sectional area. there The first section (2A) essentially serves to form a corona and the second portion (2B) substantially to form a electrostatic deposition field. Through this two-stage education the inner electrode (2), wherein the corona to a certain Section (2A) is limited and not over the entire length the inner electrode (2) extends, in a known manner with regard to the applied electric power economical operation of the Ensured Elektroabscheiders at the same time good deposition. Here, the corona forming portion (2A) of the inner electrode (2) preferably formed as a needle. However, it is e.g. also provided the corona forming the first portion (2A) as the inflow side conical or generally pointed extension of the second portion (2B) of the inner electrode (2) to design.

For cleaning the needle (2A), a cleaning body (3) is provided. The cleaning takes place by a relative movement of the cleaning body (3) against the needle (2A) in touching contact therewith. The actuating means (4) for effecting this relative movement is according to the invention in the hollow second section (2B) the inner electrode (2) is arranged. According to the in FIGS. 1 and 2 illustrated embodiment, the needle (2A) is opposite to the cleaning the immovable cleaning body (3) moved while according to the embodiments shown in Figures 3 to 7 the cleaning body (3) opposite the fixed needle (2A) is shifted.

When using the electrostatic precipitator on an internal combustion engine Preferably, such an actuating means (4) is selected, the the relative movement between the cleaning body by means of its own engine Energies such as temperature or pressure gradients or vibrations causes. When using the electrostatic precipitator for the removal of Crankcase gases is preferably an expansion element (4) used, with the engine running through the heat through the hot crankcase gas expands and so forcefully on a Tappet (4A) acts, which then extended against the action of a spring (5) becomes. When the engine stops, the temperature drops to the ambient temperature, so that the plunger (4A) by the action of a spring (5) is retracted. The spring (5) is also in the hollow inner electrode (2) housed and can act as a restoring actuator be designated. The needle (2A) is in one with the Expansion element (4) connected upstream Sleeve (4B) arranged. It can for example be pressed into this be. The sleeve (4B) may be integral with the expansion element (4) be connected or as a separate component to this be arranged. On the opposite side of the needle (2A) of the expansion element (4), the plunger (4A) is arranged, the within the hollow inner electrode (2) on a fixed there Pin (6) supported as an abutment. The spring (5) is supported on the one hand on a contour of the inner electrode (2) and on the other hand a projection of the expansion element (4) or on a projection a body surrounding the expansion element (e.g. above-mentioned sleeve).

The cleaning body (3) is preferably at the upstream end the hollow second portion (28) of the inner electrode (2) is arranged. For this purpose, the inner electrode (2) has a small opening there on, in which the cleaning body (3) is pressed or clipped. The cleaning body (3) itself is preferably of an elastomeric plate formed, which pierced by the needle (2A) for cleaning becomes. However, it is e.g. also provided, the cleaning body as a cleaning brush with radially inwardly projecting micro-bristles train.

The operation of the needle cleaning according to the execution of Figs. 1 and 2 is the following: Warm up after turning on the engine when the engine is running hot crankcase gases and the hot Engine compartment overall, the expansion element (4). Thereupon drives the relative to the pin (6) supporting the plunger (4A) and moves the expansion element (4) with the located thereon Needle (2A) against the action of the spring (5) in the drawing down. The needle (2A) pierces the cleaning body (3). In operating condition of the electrostatic precipitator with the engine running the towers Needle (2A) as the corona forming portion of the inner electrode (2) out of the second section (2B) of the inner electrode (2). At engine standstill and consequent cooling the biased Spring (5) the expansion element (4) with the needle (2A) back again, wherein the plunger (4A) is retracted. In this movement the needle (2A) is in touching contact with the cleaning body (3) cleaned during retraction, with the impurities be stripped off.

To the expansion element (4) after switching on the engine To heat up as quickly as possible and thus the needle (2A) in the operating position to bring the hot crankcase gases through the hollow inner electrode (2), in which also the expansion element (4) is housed, derived. For this purpose, the hollow inner electrode Inlets (2C) for the gas on which the room between the inner electrode (2) and the collecting electrode (1A) connect to the cavity in the inner electrode (2). These openings are preferably as in the longitudinal direction of the inner electrode (2) formed slots (2C) executed. Through these slots (2C) is also advantageous as the counter bearing for the plunger (4A) serving pin (6) in the hollow inner electrode (2) and kept it there. The discharge of the purified gas The hollow inner electrode (2) also allows a compact Construction of the electrostatic precipitator.

In the embodiment according to Figures 1 and 2, the needle (2A) via a sleeve (4B) in electrically conductive contact with the second hollow portion (2B) of the inner electrode (2) is at the same potential as the inner electrode (2) held.

A smaller diameter of the tube (1) can be made possible if in a modification of the embodiment of FIGS. 1 and 2 the Expansion element (4) not completely disposed within the tube (1) is, but if only plunger (4A) of the expansion element (4) extends into the tube (1), the main body of the expansion element (4) in the drawing so z. B. above the plunger (4A) is provided.

In the embodiment according to FIGS. 3 to 7, the needle (2A) is in the second hollow portion (2B) of the inner electrode (2) fixedly arranged (for example, pressed in). Here, the cleaning body (3) is moved, while the needle (2A) is stationary. For this purpose is one with the Plunger (4A) of the expansion element (4) connected holding element (8) for the cleaning body (3), said retaining element (8) with the plunger (4A) is moved. For longitudinally displaceable Receiving the retaining element (8) and for connecting the retaining element (8) with the plunger (4A), the hollow inner electrode (2) in Longitudinally extending slots (2C) on. It also serve in this Take the slots (2C) to drain the hot crankcase gases via the hollow inner electrode (2). The holding element (8) is in the illustrated variant designed as a retaining bracket, the inflow side a ring (8A) for receiving the cleaning body (3). The gas to be cleaned can be at the center of the cleaning body (3) Pass ring (8A) fixing webs (8B) into the pipe (1). For centering the cleaning body (3) in alignment with the needle (1A) the retaining bracket (8) is coaxial with the collecting electrode via the ring (8C) (1A). This is especially true in FIG. 7 clarified. This ensures that the cleaning body (3) from the needle (2A) is always pierced at the same point. This is in particular in a cleaning body (3) made of elastomer of Advantage, since otherwise in a variety of puncture sites the elastomer would be quickly destroyed, whereas the electrostatic precipitator maintenance free should be designed as a lifetime component.

In the embodiment shown in Figures 3 to 5 supports the spring (5) on the one hand relative to the retaining element (8) and on the other opposite to the tube (1) final closure head (7) from.

As shown in Figures 3 and 4, the holding element (8) in addition a circumferential cleaning lip (8C) for cleaning the collecting electrode (1A). This allows the needle (2A) and the Precipitation electrode (1A) advantageously simultaneously with a single mechanism to be cleaned. In addition, the Cleaning lip (8C) also - as mentioned above - the centering serve the cleaning body (3).

In an embodiment, not shown, it is intended that Forming plunger of the expansion element as the corona forming needle wherein the spring is then on a connected to the plunger Support collar supported.

Instead of an expansion element plus spring for effecting the Relative movement between cleaning body and needle, may e.g. also a motor-driven running in the hollow inner electrode Threaded spindle can be used as an actuator. It is also intended as an actuator by means of oil or To use air pressure actuated cylinder, which then at least partially runs in the hollow inner electrode.

An independent of the cleaning of the corona forming needle Aspect of the invention is the sole cleaning of the collecting electrode by means of a arranged in the cavity of the inner electrode Actuating mechanism. For this, e.g. for training a cleaning device, the holding element (8) as shown in FIGS. 3 and 4 shown used, wherein the holding element then only one having circumferential cleaning lip (8C). The cleaning body (3) then does not have to hold the retaining element (8).

LIST OF REFERENCE NUMBERS

1)

pipe

1A)

Inner wall / precipitation electrode

2)

inner electrode

2A)

first section of the inner electrode / needle

2 B)

second section of the inner electrode

2C)

Slots in the inner electrode

3)

cleaning body

4)

Actuating means (expansion element) for effecting the relative movement of cleaning body and needle

4A)

tappet

4B)

Sleeve on the expansion element for receiving the needle

5)

feather

6)

Spigot as an abutment for the plunger

7)

Locking head of the pipe

8th)

Retaining element for the cleaning body

8A)

ring

8B)

Stege

8C)

Cleaning lip for the low-voltage electrode

Claims (15)

1. Electrostatic separator for the separation of fluid or solid particles from a gas stream, comprising

   a tube (1), through which the gas to be cleaned flows in a longitudinal direction and the inner walling (1A) of which forms a collecting electrode for the particles to be separated,

   an inner electrode (2) arranged centrally in a longitudinal direction inside the tube (1), where

   in the space between this inner electrode (2) and the collecting electrode (1A) an electric high-tension field is disposed,

   the inner electrode (2) incorporates in the inflow side a first portion (2A) with a small cross-sectional area and on the outflow side a second portion (2B) with a cross-sectional area which is larger than this first portion (2A),

   where the first portion (2A) serves essentially to form a corona

   and the second portion (2B) serves essentially to form an electrostatic separation field,

   a cleaning element (3) for cleaning the portion (2A) of the inner electrode (2) forming the corona, where the cleaning is done by a movement of the cleaning element (3) relative to the portion (2A) of the inner electrode (2) and in contact with this portion (2A),

   at least one actuating means (4) to effect the movement of the cleaning element (3) relative to the section (2A) of the inner electrode (2) forming the corona,

   characterised in that at least the second portion (28) of the inner electrode (2) is at least partly constructed hollow, where the space in the inner electrode (2) receives at least one part of the actuating means (4) and/or, connected to the actuating means (4), at least one force transmitting means for effecting the movement of the cleaning element (3) relative to the portion (2A) of the inner electrode (2) forming the corona.
2. Electrostatic separator in accordance with claim 1, where the electrostatic separator is driven on an internal-combustion engine, characterised in that using motor-inherent power sources such as temperature or pressure differences or vibration the actuating means (4) effects the movement of the cleaning element (3) relative to the portion (2A) of the inner electrode forming the corona.
3. Electrostatic separator in accordance with claim 2, characterised in that the actuating means (4) is an extending element which is connected thermally or by means of a pressure line to a motor-inherent power source, where,

   while the motor is running, the extending element (4) retains the first portion (2A) of the inner electrode (2) in a first position against the action of a spring (5) and relative to a cleaning element (3) arranged so as to be fixed in the electrostatic separator,

   while the motor is stationary, the first portion (2A) of the inner electrode (2) is retained with the aid of a spring in a second position which is set along the longitudinal axis of the inner electrode (2) at a distance from the first position and relative to the cleaning element (3), which is arranged so as to be fixed in the electrostatic separator.
4. Electrostatic separator in accordance with claim 3, characterised in that the extending element (4) and/or the spring (5) is arranged at least partly in the space in the inner electrode (2).
5. Electrostatic separator in accordance with claim 3 or 4, characterised in that the cleaning element (3) is fixed on the second portion (2B) of the inner electrode (2), preferably on its inflow-side end.
6. Electrostatic separator in accordance with one of claims 3 or 4, characterised in that the cleaning element (3) is fixed by means of spacing members centrally in the tube (1) forming the collecting electrode.
7. Electrostatic separator in accordance with claim 2, characterised in that the actuating means (4) is an extending element which is connected thermally or by means of a pressure line to a motor-inherent power source, where,

   while the motor is running, the extending element (4) retains the cleaning element (3) in a first position against the action of a spring (5) and relative to the immovable first portion (2A) of the inner electrode (2),

   while the motor is stationary, the cleaning element (3) is retained with the aid of a spring in a second position set along the longitudinal axis of the inner electrode at a distance from the first position and relative to the immovable first portion (2A) of the inner electrode (2).
8. Electrostatic separator in accordance with claim 7, characterised in that the extending element (4) and/or the spring (5) is arranged at least partly in the space in the inner electrode (2).
9. Electrostatic separator in accordance with claim 7 or 8, characterised in that the inner electrode (2) in its hollow second portion (2B) incorporates at least one slot (2C) extending along the inner electrode (2) for longitudinally displaceable reception of a retaining element (8) for the cleaning element (3), via which retaining element (8) the cleaning element (3) is displaceably coupled to the extending element (4).
10. Electrostatic separator in accordance with claim 9, characterised in that the retaining element (8) is at least in one part-area guided coaxially to centre the cleaning element (3) of the collecting electrode (1A).
11. Electrostatic separator in accordance with claim 10, characterised in that the retaining element (8) for the cleaning element (3) incorporates a cleaning lip (8C) for the collecting electrode (1A), which cleaning lip (8C) extends all the way round and is in contact with the collecting electrode (1A) and which collecting electrode (1A) also serves to centre the cleaning element (3).
12. Electrostatic separator for separating fluid or solid particles from a gas stream, comprising

    a tube (1) through which the gas to be cleaned flows in a longitudinal direction and the inner walling (1A) of which forms a collecting electrode for the particles to be separated,

    an inner electrode arranged centrally in a longitudinal direction within the tube (1), where

    in the space between this inner electrode (2) and the collecting electrode (1A) an electric high-tension field is disposed,

    the inner electrode (2) incorporates on the inflow side a first portion (2A) with

    a small cross-sectional area and on the outflow side a second portion (2B) with a cross-sectional area which is larger than this first portion (2A), where the first portion (2A) serves essentially to form a corona and the second portion (2B) serves essentially to form an electrostatic separation field,

    characterised in that

    at least the second portion (2B) of the inner electrode (2) is constructed at least partly hollow, the space in the inner electrode (2) receives at least a part of an actuating means (4) and/or, connected to the actuating means (4), at least one force transmitting means for a cleaning device (8,8C) cleaning the collecting electrode (1A).
13. Electrostatic separator in accordance with claim 12, characterised in that the inner electrode (2) incorporates in its hollow second portion (2B) at least one slot (2C) extending along the inner electrode (2) for longitudinally displaceable reception of the cleaning device (8), where the cleaning device (8,8C) is coupled via the space in the inner electrode (2) to the actuating means effecting the longitudinal displacement of the cleaning device.
14. Electrostatic separator in accordance with claim 12 or 13, characterised in that the cleaning device incorporates a cleaning lip (8C) which extends all the way round and is in contact with the collecting electrode (1A).
15. Electrostatic separator in accordance with any of the foregoing claims 1 to 12, characterised in that the cleaning element (3) is formed from an elastomer which is pierced by the first portion of the inner electrode (2), which first portion is constructed as a needle (2A).

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