DE102007010973B4 - Electrostatic precipitator for a small combustion plant - Google Patents

Abstract

Electrostatic precipitator for a small combustion plant,
- with several filter electrodes (12.1-12.8), and
- With several exhaust channels (9.1-9.8), wherein in the exhaust ducts (9.1-9.8) each one of the filter electrodes (12.1-12.8) is arranged.

Description

Technical area

The The invention relates to an electrostatic precipitator for a small combustion plant. Small combustion plants are for example in private households and to find in trades and usually have a performance of up to 70 KW. Small combustion plants include chimney systems, Individual room furnaces, fireplace furnaces, tiled stoves, room stoves, cookers, ovens and boilers made with wood, straw or another regenerative Fuel or with coal, oil or gas fired.

conventional Small firing systems fired, especially when operated with solid fuels disproportionately high in terms of total smoke emission powdery Pollutants in the atmosphere. In addition, small combustion plants, albeit irregularly, often used to make plastic, cardboard, paper, combustible building material and burn painted or coated wood. This leads to a considerable additional Dust emission. With the help of an electrostatic filter, which in the exhaust pipe the firing system is located, can be located in the flue gas Particles also with an aerodynamic diameter of less retained as 10 microns which benefits the air hygiene directly.

The In the flue gas stream existing solid and liquid particles are in the electrostatic precipitator electrostatically charged by means of a filter electrode, in one deflected by the electric filter generated electric field and at a meant for separation area deposited. With the help of such an electrostatic precipitator can be Separate dust particles and aerosols with particle sizes from 0.01 to 60 μm.

State of the art

From the post-published German patent DE 10 2006 003 028.1 Such an electrostatic precipitator is known for a firing system. The electrostatic precipitator has a filter electrode and an electrode holder for holding and supplying voltage to the filter electrode in the exhaust passage.

Furthermore, from the prior art WO 00/33945 A method and apparatus is known which utilizes low temperature plasma and electrostatic filtering technology to remove particulates and pollutants from the exhaust gas of an incinerator. The device comprises an electrode whose upper end is fixed to a frame and hung in the chimney of a combustion plant. The degree of deposition is limited, however. The more particles that flow past the electrode, the lower the separation efficiency, because the electrode can only electrostatically charge a limited number of particles.

From the publication DE 33 24 803 C2 is a dust separator for mobile use known. The Staubabscheidegerät is provided to be installed in a dust measuring device.

From the publication DD 1592 95 C is an electrostatic precipitator for cleaning a small amount of a sample gas of dusty impurities known which can be used in the flue gas analysis of industrial furnaces, preferably on melting units in the glass industry.

Presentation of the invention

A The object of the invention is an electrostatic precipitator for a small combustion plant specify where the degree of separation is optimized.

Favorable Way lets the electrostatic precipitator according to the invention operate at a lower high voltage than those from the state the art known electrostatic precipitator. Due to the lower high voltage the operational safety is increased, the operating time increases and the maintenance intervals are extended.

The Task is accompanied by an electric filter for a firing system the features according to claim 1 solved.

The electrostatic precipitator according to the invention for a small combustion plant includes a plurality of filter electrodes and a plurality of exhaust channels, wherein in the exhaust ducts in each case a filter electrode is arranged.

advantageous Further developments of the invention will become apparent from the specified in the dependent claims Features.

at a development of the electrostatic filter according to the invention is a casing provided in which the exhaust ducts are arranged. This has the advantage that thereby the electrostatic precipitator a compact unit, module, or insert that forms quickly and can be easily put on the small combustion plant. Thus, the cost of mounting the electrostatic precipitator is kept small. In addition, this solution has the advantage that the electrostatic filter as a retrofit quickly, easily and easily on site on an existing small combustion plant can be mounted.

In one embodiment of the electrostatic filter according to the invention, one end of the filter electrode is pointed. This can be the number of increase electrical charge carriers sprayed by the filter electrode.

at a further embodiment the electrostatic precipitator according to the invention protrudes the first end of the filter electrode out of the exhaust passage. This has the advantage that the from the first end of the filter electrode outgoing field strength elevated can be, without causing electrical flashovers and thus to a malfunction. Especially when the first end of the filter electrode is pointed, Already at a relatively low high voltage, this happens size Field strength that sufficient ionization is ensured. Would the filter electrode with this high field strength operated within the exhaust passage, this could be in the exhaust duct under circumstances lead to electrical flashovers. By doing the filter electrode protrudes from the exhaust duct, the risk of electric flashovers and thus avoiding a malfunction become.

advantageously, is the electrostatic precipitator according to the invention an electrode holder is provided, which is a high voltage line wherein the filter electrodes are connected to the high voltage line are. In this way, all filter electrodes with supply a single high voltage line. The cost of materials is minimized. In addition, you can the filter electrodes combined into one module and as Assembly assembled or replaced.

at a development of the electrostatic filter according to the invention extends the electrode holder over the length the exhaust duct. Thereby can the filter electrodes are arranged on the inlet sides of the exhaust ducts and the electrode holder attached to the outlet side of the exhaust ducts on the filter housing become. In addition, then the electrode holder in one place on the filter housing be attached, at which the exhaust gas temperature is lower than in Range of filter electrodes.

advantageously, the attachment of the electrode holder takes place on the filter housing.

moreover it is advantageous if the electrical connection of the electrostatic precipitator also on the filter housing located. In this case, the electrical connection is part of the electrostatic precipitator is, must be provided at the firing system for this purpose and an already existing combustion plant does not have to be rebuilt.

Furthermore can in the inventive electrostatic precipitator be provided that the filter electrodes by means of a releasable coupling are connected to the electrode holder. This allows the Filter electrodes for maintenance work in a simple way be removed from the electrode holder.

to solution the object is also proposed that the exhaust ducts at electrostatic precipitator according to the invention are arranged parallel to each other. This can save space. moreover is such a constructed electrostatic filter easy to produce.

at a development of the electrostatic precipitator according to the invention are the exhaust ducts U-shaped. By doing so leaves reduce the effort in the production of the electrostatic precipitator.

To a further feature of the invention, this can be further improved be by both on the inlet side and on the outlet side the exhaust ducts Filter electrodes are arranged.

at a further embodiment the electrostatic precipitator according to the invention are the exhaust ducts across from the interior of the housing sealed. The interior of the housing may be a medium for heat transfer, for example, a liquid or air. In this way can be in the smallest space achieve a combination of electrostatic precipitator and heat exchanger. Of the heat exchangers can be integrated into a heating system.

advantageously, indicates in the electrostatic precipitator according to the invention the housing an inlet and an outlet for the heat transfer medium on. This can be cool Medium in the housing initiated and that on the walls the exhaust ducts heated Medium again from the housing derived and used for example for heating a living space become.

Finally, can in the electrostatic filter according to the invention a disk-shaped Isolation can be provided, which is arranged on the electrode holder.

Brief description of the drawings

in the Below, the invention with several embodiments with reference to eleven figures further explained.

1 shows a first possible embodiment of the electrostatic filter according to the invention in plan view in cross section.

2 shows the first embodiment of the electrostatic filter according to the invention in the side view in cross section.

3 shows an oven with the invention mounted on the smoke outlet of the furnace electrostatic precipitator.

4 shows a second possible embodiment of the electrostatic precipitator according to the invention in plan view.

5 shows a third possible embodiment of the electrostatic precipitator according to the invention in plan view.

6 shows a further possible embodiment of a furnace with the mounted on the exhaust gas outlet of the furnace electrostatic filter in the side view in section.

7 shows the embodiment of the furnace 6 in the frontal view.

8th shows a fourth possible embodiment of the electrostatic filter according to the invention in the front view.

9 shows the fourth embodiment of the electrostatic filter according to the invention in the side view in cross section.

10 shows the fourth embodiment of the electrostatic filter according to the invention in plan view in section.

11 shows an essay on a furnace with the electrostatic precipitator according to the invention in the side view in section.

Ways to execute the invention

In 1 is a first possible embodiment of the electrostatic precipitator according to the invention for small combustion systems in plan view shown in section. In 2 the first embodiment of the electrostatic filter according to the invention is shown in section in the side view. In a housing 1 are four pipes 2 . 3 . 4 and 5 arranged, which are the walls of the exhaust ducts 9.1 . 9.2 . 9.3 respectively 9.4 form. In the center of the housing 1 there is another pipe 6 in which an electrode holder 8th is provided. The electrode holder 8th sticks out of the pipe 6 out and carry with the help of four retaining arms 11.1 . 11.2 . 11.3 and 11.4 one filter electrode each 12.1 . 12.2 . 12.3 respectively 12.4 , The holding arms 11.1 to 11.4 are designed to hold the filter electrodes 12.1 to 12.4 and the guide sleeves 13.1 to 13.4 for the filter electrodes 12.1 to 12.4 essentially in the center of the exhaust ducts 9.1 to 9.4 Keep in the axial direction. Below the case 1 is the exhaust pipe 7 which is in 1 is drawn by dashed lines, and which the exhaust gas produced by a furnace to the four exhaust ducts 9.1 to 9.4 passes.

With the help of the filter electrodes 12.1 to 12.4 , which via the electrode holder 8th be supplied with high voltage, the particles in the exhaust gas are charged electrostatically. Because the case 1 as well as the pipes 2 . 3 . 4 and 5 are grounded, forms between the electrode 12.1 and the tube 2 an electric field that causes the electrostatically charged particles to stick to the inside of the tube 2 deposit. The same applies analogously to the electrode 12.2 and the pipe 3 , the electrode 12.3 and the pipe 4 as well as the electrode 12.4 and the pipe 5 ,

The of the holding arms 11.1 to 11.4 held filter electrodes 12.1 to 12.4 each project into the exhaust ducts with their first ends 9.1 to 9.4 , The second ends 14.1 to 14.4 the filter electrodes 12.1 to 12.4 are located outside the exhaust ducts 9.1 to 9.4 , The electrode holder 8th has inside a high voltage line 10 acting as a power supply for the individual filter electrodes 12.1 to 12.4 serves and their end 14.5 may be formed as a further filter electrode.

The ends 14.1 to 14.5 the filter electrodes are preferably pointed. As a result, the number of charge carriers sprayed by the electrodes can be increased. To improve the ionization, the filter electrodes can 12.1 to 12.5 also be made of very thin wire or have sharp edges and burrs.

This has the advantage of being from the ends 14.1 to 14.5 the filter electrodes outgoing field strength can be increased without causing electrical flashovers. Especially if the ends 14.1 to 14.5 The filter electrodes are pointed, already at a relatively low high voltage such a large field strength that sufficient ionization is ensured. Would the filter electrodes 12.1 to 12.4 with this high field strength within the exhaust channels 9.1 to 9.4 could be operated, this in the exhaust ducts 9.1 to 9.4 may cause electrical flashovers. By the filter electrodes from the exhaust ducts 9.1 to 9.4 protrude, the risk of electrical flashovers and thus a malfunction can be avoided. In this embodiment, therefore, there is an ionization zone in front of the inlets of the exhaust ducts 9.1 to 9.4 and a separation zone within the exhaust channels 9.1 to 9.4 , In the ionization zone, the particles in the exhaust gas stream are ionized and then in the separation zone on the walls of the exhaust gas channels 9.1 to 9.4 deposited.

The in the pipe 6 arranged filter electrode holder 8th is via a detachable coupling 27 with egg a holding arm 28 connected. The coupling 27 has a rebate and has a funnel-shaped guide to the insertion of the filter electrode holder 8th to facilitate in the clutch. Instead of the Renkverschlusses also a bayonet lock or a releasable snap connection can be provided.

The holding arm 28 is formed as an insulator and carries in its interior a high voltage line, which from the housing 1 led out and at the end of an electrical connection 28.1 having. About the connection 28.1 are the filter electrodes 12.1 to 12.4 connectable to a high voltage source not shown in the figures. The holding arm 28 is over a multistage insulator 29 . 30 on the housing 1 attached. At the arm 28 may additionally be provided a plate or disc-shaped insulator, as in the publication DE 10 2006 003 028 described, may be formed.

The pipes 2 . 3 . 4 . 5 and 6 are opposite the interior 17 of the housing 1 sealed. This can for example be done by the pipes 2 to 6 on the input side with the housing bottom 1.1 and on the output side with the housing cover 1.2 are welded. The housing 1 has a connection 18 on, over which a heat exchange medium into the interior 17 of the housing 1 can be directed. About a connection 22 the heat exchanger medium returns from the housing 1 out. Water can be used as the heat exchange medium.

While the hot exhaust gas from the furnace through the exhaust ducts 9.1 to 9.4 flows, cools the exhaust gas and releases the heat energy to the heat exchange medium. As a result, the heat exchange medium heats up and can via the connection 22 , which is also referred to as flow VL, again from the housing interior 17 be removed. The connection 18 is also referred to as return RL. To ensure the best possible distribution of the heat exchanger medium in the interior 17 of the housing 1 to reach the heat exchanger medium through a pipe 19 in the interior 17 to a location that is as far away from the flow VL, passed.

In the interior 17 is additionally a coiled line 21 provided, in which also a heat exchange medium is ge leads. About a connection 20 The heat exchanger medium is in the line 21 initiated and via a connection 23 taken again. The administration 21 forms a safety heat exchanger and is part of a safety circuit that ensures that the entire system does not overheat and is damaged in the event of a fault.

In 3 shows a possible embodiment of a firing plant with the electrostatic precipitator according to the invention arranged above it. That in the combustion chamber 31 The firing system produces exhaust gas via a hood 32 led to the electrostatic precipitator according to the invention and cleaned there. In addition, the exhaust gas heat energy is withdrawn in order to use this as heating energy for example, a living room. Advantageously, the electrostatic filter is from the combustion chamber 31 accessible. This allows the electrostatic precipitator to be easily cleaned without polluting the environment. The particles attached to the walls of the exhaust ducts 9.1 to 9.4 have been deposited fall when cleaning the electrostatic precipitator in the combustion chamber 31 ,

In 4 a second possible embodiment of the electrostatic filter according to the invention is shown in plan view. The electrostatic precipitator can, as described above, also have a heat exchanger, which in the 4 but not shown for clarity. The second embodiment of the electrostatic filter differs substantially from the first embodiment in that a total of seven round exhaust ducts 9.1 to 9.7 are provided, which are arranged in a circle. The caseback 1.1 ' has corresponding holes 33.1 to 33.7 on, which are the inlet openings for the gas channels 9.1 to 9.7 form. Basically, the two embodiments do not differ in their operation.

In 5 a third possible embodiment of the electrostatic filter according to the invention is shown in plan view. Compared to the two previous embodiments, the embodiment differs according to 5 in that a total of nine exhaust ducts 9.1 to 9.9 are provided, which have a square or rectangular cross-section. The caseback 1.1 '' has corresponding openings, which serve as inlet openings for the exhaust gas ducts 9.1 to 9.9 serve. Regarding the principle of operation of in 5 shown electrostatic filter is referred to the above description.

In 6 is another possible embodiment of a furnace in the side view shown. In 7 This firing system is shown in frontal view. Above the combustion chamber 31 is the electrostatic precipitator according to the invention. That in the combustion chamber 31 generated particulate exhaust gas is via an exhaust passage 35 passed to the electrostatic precipitator according to the invention, is through the exhaust channels 9.1 - 9.8 guided and freed from the particles. The thus purified exhaust gas exits the exhaust pipe 36 and can be fed to a fireplace, not shown in the figures. In contrast to the previous embodiments, the lower exhaust ducts 9.5 - 9.8 from the exhaust gas in flows through a first direction and the upper exhaust ducts 9.1 to 9.4 in the opposite direction.

In 8th the embodiment of the inventive electrostatic filter just described is shown in frontal view. 9 shows this embodiment of the electrostatic filter in the side view in section. 10 shows this embodiment of the electrostatic filter in plan view in section. In contrast to the previous embodiments, the electrode holder does not extend over the entire length of the exhaust ducts 9.1 - 9.8 , Rather, the filter electrodes 12.1 - 12.8 from the electrode holder 29 nearest openings of the exhaust ducts in the exhaust ducts 9.1 to 9.8 introduced.

In 11 is a further embodiment of the electrostatic precipitator according to the invention with heat exchanger in the side view shown in section. In addition to the in 8th The essay shown comprises the article according to 11 a flap 37 with which part of the exhaust ducts 9.1 to 9.4 can be closed. The flap 37 can be closed when firing to increase the draft in the chimney. If the fireplace has reached a sufficient temperature, the damper can 37 be opened. With the flap 37 For example, an electrical switch for switching on and off the electrostatic filter can be coupled. So shut up 37 is transferred automatically, the switch for the control of the electrostatic filter is actuated.

Advantageously, the electrostatic filter according to the invention can be operated at a lower high voltage than the electrostatic precipitators known from the prior art. Due to the lower high voltage, electrically conductive particles are no longer deposited on the insulator 13 . 11 . 8th . 27 . 28 . 30 . 29 from. It takes longer until a parasitic conductive layer forms on the insulator and until leakage currents from the filter electrodes 12.1 to 12.8 over the insulator 13 . 11 . 8th . 27 . 28 . 30 . 29 to the housing 1 flow. The lower high voltage increases the service life and extends maintenance intervals.

The Previous description of the embodiments according to the present This invention is for illustrative purposes only and not for purpose the restriction the invention. Within the scope of the invention are various changes and modifications possible, without departing from the scope of the invention and its equivalents.

1

casing

1.1

caseback

1.1 '

caseback

1.1 ''

caseback

1.2

housing cover

2

pipe

3

pipe

4

pipe

5

pipe

6

pipe

7

central stovepipe

8th

centrally electrode holder

9.1-9.8

exhaust ducts

10

High-voltage line

11.1-11.8

holding arms

12.1-12.8

filter electrodes

13.1-13.8

guide sleeves

14.1-14.8

end up the filter electrodes

17

inner space of the housing

18

connection

19

pipe

20

connection

21

coiled management

22

connection

23

connection

24

electrode

25

electrode

26

electrode

27

clutch

28

isolated High-voltage line

28.1

connection for high voltage source

29

bracket

30

insulator

31

combustion chamber

32

Hood

33.1-33.7

round openings

34.1-34.9

angular openings

35

channel

36

exhaust pipe

37

flap

38

baffle

RL

returns

VL

leader

Claims (17)

Electrostatic precipitator for a small combustion plant, - with several filter electrodes ( 12.1 - 12.8 ), and - with multiple exhaust channels ( 9.1 - 9.8 ), wherein in the exhaust ducts ( 9.1 - 9.8 ) each one of the filter electrodes ( 12.1 - 12.8 ) is arranged. Electrofilter according to claim 1, with a housing ( 1 ), in which the exhaust ducts ( 9.1 - 9.8 ) are arranged. Electrofilter according to claim 1 or 2, wherein one end of the filter electrode ( 12.1 ) is pointed. Electrofilter according to one of Claims 1 to 3, in which one end of the filter electrode ( 14.1 ) from the exhaust duct ( 9.1 ) sticks out. Electrofilter according to one of claims 1 to 4, having an electrode holder ( 8th . 11.1 - 11.8 ), which is a high voltage line ( 10 ) to which the filter electrodes ( 12.1 - 12.8 ) are connected. Electrofilter according to claim 5, wherein the electrode holder ( 8th . 11.1 - 11.8 ) over the length of the exhaust duct ( 9.1 ). Electrofilter according to one of the claims 1 to 6, in which the filter electrodes ( 12.1 - 12.8 . 14.1 - 14.8 ) by means of a releasable coupling ( 27 ) with the electrode holder ( 28 ) are connected. Electrofilter according to one of claims 1 to 7, in which the exhaust ducts ( 9.1 - 9.8 ) are arranged parallel to each other. Electrofilter according to one of claims 1 to 8, in which the exhaust gas channels ( 9.1 - 9.8 ) Are U-shaped. Electrofilter according to one of claims 1 to 9, wherein on the inlet side and on the outlet side of the exhaust ducts ( 9.1 - 9.8 ) Filter electrodes ( 12.1 - 12.8 ) are arranged. Electrofilter according to one of the claims 1 to 10, - in which the exhaust gas channels ( 9.1 - 9.8 ) in relation to the interior ( 17 ) of the housing ( 1 ) are sealed, and - in the interior ( 17 ) of the housing ( 1 ) can be a medium for heat transfer. Electrofilter according to claim 11, wherein the housing ( 1 ) an inlet ( 18 ) and an outlet ( 19 ) for the medium. Electrofilter according to one of the claims 2 to 12, in which the electrode holder ( 28 ) on the housing ( 1 ) is attached. Electrofilter according to one of the claims 2 to 13, in which the electrical connection ( 28.1 ) on the housing ( 1 ) is attached. Electrofilter according to one of claims 1 to 14, having a disc-shaped insulation which is located on the electrode holder ( 28 ) is arranged. Small combustion plant with the electrostatic filter according to one of the claims 1 to 15, - with an exhaust duct and a flap ( 37 ), with which the opening width of the exhaust duct is adjustable, and - with a switch for the electrostatic filter, with the flap ( 37 ) is coupled. Use of the electrostatic filter according to one of the claims 1 to 15, in a small combustion plant.