CN102614986A - PM2.5 (Particulate Matter 2.5) electrostatic precipitator with box-type dedusting area - Google Patents

Abstract

A PM2.5 electrostatic precipitator with a box-type dust removal area, which is arranged behind a conventional electrostatic precipitator system, and includes a condensation area and a box-type dust removal area connected in sequence, wherein: the condensation area is connected to the conventional electrostatic precipitator system, and the There are multiple dust collecting plates at equal intervals to form multiple dust channels in the same direction as the dust. In the same dust channel, there are discharge electrodes perpendicular to the direction of the dust and with the same polarity. The adjacent dust channels The polarity of the internal discharge electrode is opposite, so that the fine dust passing through the area is charged with different charges and condenses into large particles of fine dust at the outlet of the area; the box-type dust removal area is connected with the condensation area, and there are multiple equal intervals The bottom of each box-type dust-collecting membrane is suspended to leave a channel for large particles of dust to pass through. The box-type dust-collecting membrane is negatively charged through the connected power supply. Each box-type dust-collecting membrane The membranes on one side have the same structure, and are composed of conductive membranes and polypropylene membranes are arranged on the upper and lower sides respectively, and electrostatic dust removal is completed in this area. The invention has good effect and low cost.

Description

A kind of PM2.5 electrostatic precipitator with box dedusting area

Technical field

The present invention relates to thermoelectricity industry dedusting technology, relate in particular to a kind of PM2.5 electrostatic precipitator with box dedusting area.

Background technology

PM2.5 is meant that diameter in the atmosphere is less than or equal to the particle of 2.5 μ m, is also referred to as and can goes into the lung particle.Though he is a content component seldom in the earth atmosphere composition, he has significant effects to air quality and visibility etc.Compare with thicker Atmospheric particulates, the PM2.5 particle diameter is little, be rich in a large amount of poisonous, harmful substance, and the time of staying in atmosphere is long, fed distance is far away, thereby bigger to the influence of health and atmosphere quality.

In the period of 2000-2007, the annual industrial fumes discharge capacity of China is all above 8,000,000 tons (about 4,000,000 tons of thermoelectricity industries), wherein minuteness particle (PM10, PM2.5) about 4,000,000 tons (the thermoelectricity industry is above 3,000,000 tons).

Traditional ESP can only collect the above dust granules of PM10, and sack cleaner can be collected the micronic dust of PM2.5, but there is following shortcoming in it:

(1) be inappropriate for operation work under the condition of high temperature, moisture is important to surpass 25% when above when dust in the flue gas contains, and dust is prone to the stifled bag of sticking bag, causes cloth bag deashing difficulty, resistance to raise, and premature failure is damaged;

(2) it is big slightly to compare drag losses with electric precipitation, is generally 1000-2000Pa;

(3) when burning high-sulfur cigarette or flue gas without apparatus processes such as desulfurization, when flue gas sulphur oxide, oxynitride concentration are very high, except that the FE filtrate, the damage that all can be corroded of other chemical fibre synthetic fiber filter materials, the cloth bag lost of life;

(4) can not under " dewfall " state, work;

(5) the cloth bag renewal cost is high.

Electrostatic precipitator, sack cleaner or electricity bag convolution deduster are generally adopted in thermal power plant's dedusting.

The principle of electrostatic precipitator is:

The highfield that utilizes high-voltage DC power supply to produce makes and contains electronegative gas (for example O2, SO2, Cl2, NH3, H2O etc.) ionization in the flue gas; Produce corona discharge; And then make the dust that is suspended in the gas charged; And charged dust is arrived on the electrode opposite polarity with it, thereby realize the purpose that dust suspension is separated from gas.

The advantage of electrostatic precipitator is:

(1) efficiency of dust collection can reach 98%-99%;

(2) in electric cleaner, the energy that grit separates from air-flow is not to supply with air-flow, but directly supplies with grit, therefore, compares with other high-efficiency dust remover.The resistance of electric cleaner is lower, is merely 100-200Pa;

(3) can handle high temperature ('s below 400 ℃) gas;

(4) be applicable to large-scale engineering, the gas flow of processing is bigger, and its economic effect more obviously.

The principle of sack cleaner is:

Dust-contained airflow gets into the cylindrical shape filter bag from the bottom, when passing through the hole of filtrate, dust is got off by the filtrate detention, and the cleaning gas tream that sees through filtrate is discharged by air-purifying chamber.Be deposited on the dust layer on the filtrate, under the effect of mechanical oscillation, split away off, fall into ash bucket from filter material surface.

The advantage of sack cleaner is:

(1) efficiency of dust collection is high, and generally more than 99%, the dust content that can reach the gas in the deduster exit is 20-30mg/Nm3, and the thin dirt of sub-micron particle diameter is had higher grade dust-collection efficiency;

(2) relatively simple for structure, convenient operating maintenance;

(3) insensitive to the dust characteristic, do not receive the influence of dust specific resistance;

(4) when the synthetic fibers that adopt glass fibre and some kind are made filter bag, can stable operation under 160-200 ℃ temperature, when selecting the high-performance filtrate, some heatproof can reach 260 ℃;

(5) when being used for dry method desulfuration system, can suitably improve desulfuration efficiency;

(6) scope of processing gas flow is big, and can handle the very dusty gas of high concentration, so it can be used as the deduster of various dusty gases.Its capacity can be less than to per minute number cubic metre, arrive the air-flow of hundreds thousand of cubic metres of per minutes greatly; When adopting highdensity synthetic fibers filter bag and pulse recoil purge mode; It can handle the dusty gas that dust concentration surpasses 700000mg/m3; It both can be used for the dust removal by ventilation in dirt source, and to the dedusting such as dusty gas in the various technical process such as cement, carbon black, pitch, lime, gypsum, chemical fertilizer, to reduce the discharging of dust pollution thing.

Yet, along with the raising of national environmental standard, depend merely on the requirement that electric precipitation can not satisfy environmental protection standard fully, the increase sack cleaner receives intrinsic restrictions such as the unit air-introduced machine is exerted oneself, space again and has problems such as difficult design.

Summary of the invention

In order to overcome the shortcoming of above-mentioned prior art; The object of the present invention is to provide a kind of PM2.5 electrostatic precipitator with box dedusting area; Can realize catching the purpose of the subparticle below the PM2.5; Can realize long period, the effect that maintenance cost is low again, and then it is big to solve thermoelectricity industry fine dust discharge capacity, the problem of threatening environment.

In order to solve the problems of the technologies described above, the technical scheme that the present invention adopts is:

A kind of PM2.5 electrostatic precipitator with box dedusting area is arranged at after the conventional electric dust removing system, comprises the coalescence district 17 and box dedusting area 18 that are communicated with successively, wherein:

Coalescence district 17 and conventional electric dust removing system conducting; Be provided with equally spaced a plurality of dust collection plate 6 in the coalescence district 17; Form the micronic dust passage 7 consistent between the adjacent dust collection plate 6 with the micronic dust direction; Be provided with in the same micronic dust passage 7 perpendicular to micronic dust direction and the identical discharge electrode 8 of polarity, the polarity of discharge electrode 8 is opposite in the adjacent micronic dust passage 7, makes electric charges different on the micronic dust band through this district and becomes the bulky grain micronic dust at this exit, district coalescence;

Box dedusting area 18 is communicated with coalescence district 17; Be provided with a plurality of equally spaced box films 10 that gather dust in the box dedusting area 18; The unsettled bulky grain micronic dust passage 11 of reserving in each box film 10 bottoms of gathering dust supplies the bulky grain micronic dust to pass through; The box film 10 that gathers dust has negative electrical charge through the power supply 9 that connects, and the film bulk structure of each face of the box film 10 that gathers dust is consistent, at upper and lower surface polypropylene screen 14 is set respectively by conducting film 13 and forms.

Said box dedusting area 18 bottoms are communicated with ash bucket 15.

Said box dedusting area 18 tops are provided with the film take-up device 16 that gathers dust.

The present invention compared with prior art has the following advantages:

1) mode of employing electrostatic precipitation is effectively caught the micronic dust below the PM2.5.

The present technique method is in former electric field arranged downstream coalescence district, because the positive and negative electrode separation in coalescence district, therefore; Flying dust will obtain positive charge and negative electrical charge respectively in its passage separately, carry particle coalescence after mixed downstream of positive and negative charge, and the dust behind the coalescence is caught by the film electrostatic precipitator; Tunica fibrosa has the capturing efficiency about 99.9% for the particle below the PM2.5, when dust runs up to certain thickness, when generally being about 5mm; Film stretching device starts, and makes the flying dust layer bear very big shearing force, when the flying dust layer receives shearing force; Film can fragment into a lot of fragments, fall into ash bucket then, because need not be provided with parts such as reinforcement; Therefore staubosphere can not fragment into very little fragment, and the possibility of being carried discharging once more reduces, thereby has also improved efficiency of dust collection.

This technical method need take into full account the dust charge electrical characteristics, designs the suitable high frequency electric source and the arrangement in coalescence district, and the effect of deflector is with charged mix dust and coalescence, for follow-up dedusting provides condition.The film electrostatic precipitator is easy to install and the location because material is light, and the requirement of setting accuracy is also so strict unlike the conventional electrostatic deduster, and therefore, as long as the coalescence district is reasonable in design, tunica fibrosa is selected correct, just can guarantee the efficiency of dust collection more than 99.9%.

2) investment cost is low, and operation, maintenance cost is also low.

For 300MW boiler unit, the high frequency electric source of coalescer is 25KW, and power consumption is low.Coalescer is arranged in former electric field downstream, adds the baffle upper plate flue gas resistance less than 200Pa, characteristics such as anticorrosive owing to having, the anti-combustion of tunica fibrosa, and the life-span is several times even tens times of cloth bag, so the maintenance operation cost in its later stage is all very low.

The quality of film electrostatic precipitator is about one of percentage of conventional electrostatic deduster, and mounting cost also is lower than the conventional electrostatic deduster, and therefore, the improvement expenses that increases the traditional electrical deduster is low.The expense of each cloth bag is about 1000 yuan, and for the 300MW unit, a tablecloth bag dust collector has 600 cloth bags approximately, and therefore only the cloth bag investment is about 6,000,000 yuan, and afterbody adopts the film electrostatic precipitation to use 1700m approximately ²Tunica fibrosa, the price of tunica fibrosa is 450 yuan/m ², therefore, transforming a required expense of 300MW boiler unit is 76.5 power units.

Description of drawings

Fig. 1 is a structural representation of the present invention, and arrow is the flow direction of micronic dust among the figure.

Fig. 2 is that B-B is to view among Fig. 1, and arrow is the flow direction of micronic dust among the figure.

Fig. 3 is the present invention membrane plane figure that gathers dust.

Fig. 4 is the present invention's film cutaway view that gathers dust.

The specific embodiment

Specify embodiment of the present invention below in conjunction with accompanying drawing and embodiment.

As depicted in figs. 1 and 2, be structural representation of the present invention, arrow is the flow direction of micronic dust among the figure; Micronic dust enters into conventional electric dust removing system from import smoke box 1, and this routine electric dust removing system comprises a former electric field 2, former two electric fields 3; Former three electric fields 4 and 5 four former electric fields of former four electric fields; Micronic dust removes most of oarse-grained dust through behind this routine electric dust removing system, enters into coalescence district 17 then.

Coalescence district 17 and conventional electric dust removing system conducting; Be provided with equally spaced a plurality of dust collection plate 6 in the coalescence district 17, form a plurality of micronic dust passages 7 consistent, be provided with in the same micronic dust passage 7 perpendicular to micronic dust direction and the identical discharge electrode 8 of polarity with the micronic dust direction; The polarity of discharge electrode 8 is opposite in the adjacent micronic dust passage 7; Make through different electric charge on the micronic dust band in this district, and become the bulky grain micronic dust, enter into box dedusting area 18 afterwards at this exit, district coalescence.

Box dedusting area 18 is communicated with coalescence district 17, is provided with a plurality of equally spaced box films 10 that gather dust in the box dedusting area 18, and the film bulk structure of each face of the box film 10 that gathers dust is consistent; Like Fig. 3 and shown in Figure 4; At upper and lower surface polypropylene screen 14 is set respectively by conducting film 13 and forms, conducting film 13 has carried the performance that stretches, and polypropylene screen 14 has microcellular structure; Strengthened the micronic dust efficiency of dust collection, guaranteed efficiently removing PM2.5 and following micronic dust.Box dedusting area top is provided with the film take-up device 16 that gathers dust, and the film take-up device 16 that gathers dust connects the box film 10 that gathers dust, and can realize reeling to the box film 10 that gathers dust in vertical direction, changes the lax or tensioning state of the box film 10 that gathers dust.The box film 10 that gathers dust has negative electrical charge through the power supply 9 that connects; The unsettled bulky grain micronic dust passage 11 of reserving in each box film 10 bottoms of gathering dust supplies the bulky grain micronic dust to pass through; Micronic dust is attached to the film surface; Therefore also realize the effect of high efficiency filter, when treating that film gathers dust certain thickness (generally can be set to 5mm), started film take-up device 16; The form of staubosphere with shearing force is scavenged in the ash bucket 15 of box dedusting area bottom, and micronic dust in the ash bucket 15 and former flying dust induction system are delivered to grey storehouse in the lump then.Accomplish the flue gas of dedusting and discharge from outlet smoke box 12, after the ash disposal, the film take-up device 16 that the gathers dust film 10 that will gather dust is put back to relaxed state and is continued to gather dust.

Along with the increasingly stringent of China to soot emissions and requirement, this device can be realized the dust removing effects of good PM2.5 with lower cost.

Claims (3)

1. a PM2.5 electrostatic precipitator with box-type dust removal area is arranged after the conventional electrostatic precipitator system, and is characterized in that it comprises successively connected condensing coalescing areas (17) and box-type dust removal areas (18), wherein: The coagulation area (17) is connected to the conventional electrostatic precipitator system, and a plurality of dust collecting plates (6) at equal intervals are arranged in the coagulation area (17), and dust collecting plates (6) are formed between adjacent dust collecting plates (6). The dust channels (7) in the same direction are provided with discharge electrodes (8) perpendicular to the direction of the dust and with the same polarity in the same dust channel (7), and the discharge electrodes (8) in the adjacent dust channels (7) 8) The polarity is opposite, so that the dust passing through the area is charged with different charges and condenses into large particles of dust at the exit of the area; The box-type dust removal area (18) is connected with the condensation area (17). There are a plurality of box-type dust-collecting films (10) at equal intervals in the box-type dust-removal area (18). The bottom of each box-type dust-collecting film (10) The large particle dust channel (11) is suspended in the air for the passage of the large particle dust, and the box-type dust collection film (10) has a negative charge through the connected power supply (9), and each side of the box-type dust collection film (10) The membrane bodies have the same structure, and are composed of conductive membranes (13) and polypropylene membranes (14) respectively arranged on the upper and lower surfaces. 2. The PM2.5 electrostatic precipitator with box-type dust removal area according to claim 1, characterized in that, the bottom of the box-type dust removal area (18) is connected to the ash hopper (15). 3. The PM2.5 electrostatic precipitator with a box-type dust removal area according to claim 1, characterized in that a dust-collecting film tensioning device (16) is arranged on the top of the box-type dust removal area (18).

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