CN106422730A

CN106422730A - Double wet method flue gas desulphurization and dust removal treatment process

Info

Publication number: CN106422730A
Application number: CN201610773735.7A
Authority: CN
Inventors: 张明鑫
Original assignee: 张明鑫
Priority date: 2016-08-31
Filing date: 2016-08-31
Publication date: 2017-02-22
Anticipated expiration: 2036-08-31
Also published as: CN106422730B

Abstract

The invention relates to a double wet method flue gas desulphurization and dust removal treatment process. The double wet method flue gas desulphurization and dust removal treatment process is characterized in that calcium carbonate and ammonia water or urea are matched in a furnace to remove NO and NO2, then particulate matters and solute carried by first-stage dust removal and desulphurization are cleaned by using second-stage dust removing water through an n-shaped two-stage wet method desulphurization and dust removal process; second-stage water is desulfurized and denitrified by using the characteristics that ammonia is harmless and is low in gaseous conversion temperature; formed ammonium sulfite refluxes for secondary utilization, and a double-alkali method desulphurization process is formed in first-stage dust removing water. The water content in flue gas at the tail end is reduced by adopting a cyclone centrifugal force, and main pollutants such as SO2, NOX and soot in flue gas emission in a boiler can be discharged at ultra-low emission.

Description

Double wet process of FGD dust removal process techniques

Technical field

The present invention relates to combustion product gases handling process, carries out the integrated treatment of desulfurization, denitrogenation, dedusting especially for flue gas Technique, belongs to burning waste gas processing technology field.

Background technology

Shandong Province administers area as emphasis Air Pollutant Emission, promulgates from the Shandong Province on the 1st of September in 2013《Shandong Save emission standard of air pollutants for boilers》Industrial Boiler standard limit of smog release is adjusted to SO₂<300mg/m³, NO_X<400 mg/ m³, dust<50 mg/m³.Upgrade to SO from January 1st, 2016₂<200mg/m³NO_X<300 mg/m³, dust<20 mg/m³. It is an important topic to find comprehensive flue gas processing method that is a kind of not only economic but also being suitable for.

Now in specialty is divided, desulphurization denitration and dedusting are divided into two specialty subitem researchs, with the discharge to flue dust Standard is more and more stricter, and desulphurization denitration product has had become as the main contributions on flue dust impact.Ensureing denitrification efficiency While how to handle the product of desulphurization denitration well be then the key for ensureing flue dust qualified discharge.

Hereinafter current boiler atmosphere pollution disposal status are analyzed

1st, dedusting：

Energy condition due to China is limited, and coal is all the main primary energy of China all the time, and nineteen ninety-five was to 2011 Coal average accounting in China's primary energy consumption reaches 70% or so.This energy resource structure based on coal determines that coal fires Carbon dioxide, sulfur dioxide, flue dust, dust etc. produced by burning is the key factor for causing China's atmospheric pollution.Meanwhile, metallurgical, Flue dust that the high speed development of the industries such as cement, waste incineration brings, dust emission further increase the pressure of environmental conservation.According to Chinese Ministry of Environmental Protection's data, China's smoke discharge amount in 2010 is that 829.1 ten thousand tons, wherein industrial fumes discharge capacity is 603.2 ten thousand tons.Cigarette Dirt, dust are mainly made up of particulate matter, in mining, metallurgy, the production of many industrial departments such as machinery, building materials, light industry, electric power All can produce in a large number.For environment, the dust long-time for entering air is floated and can reduce atmospheric visibility, can cause coal smoke type Pollution；For human body, respirable dust can cause gradual pulmonary fibrosiss, cause insufficiency of pulmonary function, contain in dust Trace heavy metal element, radioelement can also cause alzheimer disease, the fatal disease such as leukemia.In order to mitigate these Harm, cleaner unit is as Main Means and the equipment of air dedusting, widely used by each industrial department.In all kinds of cleaner units In the presence of, China's industrial fumes, dust removal amount are lifted steadily.

Dedusting index is lifted

According to《Fossil-fuel power plant atmospheric pollutant emission standard》（GB13223-2011）Power plants are coal-fired, fuel oil consump-tion is executed 30mg/m³Concentration of emission limit value, key area is according to 20mg/m³Execute（Existing thermal power plant was executed from 1 day July in 2014, Newly-built thermal power plant was executed from 1 day January in 2012）.The standard is compared to discharge standard before this（GB13223-2003）Regulation 50 200mg/m³Emission limit has and is greatly improved.

In June, 2012, Chinese Ministry of Environmental Protection has issued steel industry and steel sintering, the new mark of pelletizing industrial air pollution thing discharge Accurate.New standard is by granular material discharged concentration 100mg/m³—150mg/m³It is adjusted to 20mg/m³—50mg/m³, this requires enterprise Must highly effective matched cleaner particulate matter is administered.

2nd, desulfurization：

In the middle of double alkali method desulfurizing technology, the technique that we commonly use is that Dual alkali is sodium hydroxide+limestone or quick lime.Work Skill principle is as follows：

Desulphurization reaction

Na₂CO₃+ SO₂→ Na₂SO₃+ CO₂（1）

2NaOH + SO₂→ Na2SO₃+ H₂O （2）

Na₂SO₃+ SO₂+ H₂O → 2NaHSO₃（3）

Wherein：

Formula（1）For startup stage Na₂CO₃Solution absorbs SO₂Reaction；

Formula（2）For regenerated liquid pH value higher when（During higher than 9）, solution absorption SO₂Primary response；

Formula（3）Relatively low for solution ph（5~9）When primary response.

Regenerative process

Ca(OH)2+Na2SO₃→2NaOH+CaSO₃（4）

Ca(OH)2+2NaHSO3→Na2SO3+CaSO3.1/2H2O+3/2H2O （5）

Oxidizing process (side reaction)

CaSO3+1/2O2→CaSO4 （6）

CaSO3.1/2H2O+1/2O2→CaSO4+1/2H2O （7）

Which is the disadvantage is that, have two kinds of desulfurization products to be respectively calcium sulfate, sodium sulfite, its boiling point is respectively 1484 DEG C and 1465 ℃.Sodium sulfite is in liquid after the completion of desulfurization, but after temperature rising or loss of water, can form solid salt；Using calcium method Or in the sulfur removal technology of magnesium processes, the solids of formation are calcium granule or magnesium granules.Gypsum rain or saline that namely we often say Rain.Under new standard, no matter which kind of sulfur removal technology is adopted, due to the impact of desulphurization denitration product, flue dust index is all unable to reach ＜ 20mg/m³.

, denitrogenation：

Strict regulations were not carried out to denitrogenation in the past in 2013 due to country, simply toll administration, institute were carried out according to full discharge capacity With the denitrification equipment of domestic each high-power station nor a lot, it is concentrated mainly in the middle of several key cities, two-stage nitration combustion technology, dry Method denitrogenation technology etc. is burnt in the middle of stove in layer and is run without equipment investment.Wherein NO₂Aqueous alkali can be passed through, but NO is needed into catalysis Afterwards, alkaline matter can just be neutralized.

, dehydration

Originally in the middle of sulfur removal technology commonly used both at home and abroad, conventional wet desulfurizing process have calcium method（Limestone-based process, Calx Method（Calcium oxide）, Dual alkali（Sodium hydroxide+limestone or Calx）, ammonia process, sodium alkali, magnesium oxide method etc..

In the middle of existing wet desulfurizing process, certain calcium class or salts substances in the middle of its desulfurization product, can be all carried.Finally Cause the increase of flue dust index.The discharge value of desulfurization removing nitric efficiency its flue dust higher is also higher.As the country is to environmental emission The stepping up of standard, in SO₂And NO_XWhile minimum discharge, flue dust is also almost required to zero-emission.So reduce wet method taking off Impact of the sulfur denitrogenation product to flue dust index and the final moisture content for reducing flue gas are the major subjects of exhaust-gas treatment.

In order to reduce the moisture content in flue gas, meet minimum discharge at this stage, make soot emissions index up to standard.Wet desulphurization The flue gas moisture content of device reaches 10-18%.

The country is most commonly used that：

1st, wet electric dust-removing technology.Carried using the motion of high-tension electricity both positive and negative polarity electronics and absorb water smoke.

2nd, lateral arrangement import ridge type demister.

Above two smoke dewatering device wet-esp ionizes the collective effect of corrosion and acid and alkali corrosion due to existing, Cause the service life of anode and cathode not long, using for general glass steel material maintains 2-4, the 6-8 of stainless steel.And per Year is required for removable parts anode and cathode equipment.Equipment investment is higher.

Ridge type demister initial investment is relatively low with respect to wet-esp, but cannot cover comprehensively due to rinsing, and is formed with Demisting dead angle, causes subregion structure blocking.In now corrected system, most of system operation is not sufficiently stable, warp Perseverance is exceeded.Final flue gas moisture is too high, is the exceeded key factor of flue dust.

Content of the invention

It is contemplated that reduce the impact of desulphurization denitration solid-state product and solute to flue dust in existing Wet Flue Gas Desulfurization Technique, and Effectively reduce flue gas moisture content；And then a kind of pair of wet process of FGD dust removal process technique is provided.The handling process not only economy but also Existing wet desulphurization denitrating technique, the final product of reduction desulphurization denitration is can adapt to, realizes burning waste gas minimum discharge.

For solving the above problems, the technical solution adopted in the present invention is：

Double wet process of FGD dust removal process techniques, are characterized in that, its structure includes：

The first grade desulfurizing dust arrester of first grade desulfurizing dust removal process is carried out to flue gas；

The two-grade desulfurizing dust arrester of two-grade desulfurizing dust removal process is carried out to the flue gas after first grade desulfurizing dust removal process；And

It is external in the two-grade desulfurizing dust arrester and participates in the ammonia adding set of the ammonia process of desulfurization；

Wherein, the first grade desulfurizing dust arrester includes shaped Venturi dedusting tower 30, desulfurization pond and circulation line；Described two grades take off Sulfur dust arrester includes clear water spray column 13, dedusting pond and circulation line；The venturi of the first grade desulfurizing dust arrester is removed It is connected by top between chimney 30 and the clear water spray column 13 of the two-grade desulfurizing dust arrester, to constitute the double wet towers of n shape Structure；

The ammonia adding set includes ammonia water tank 12 and the aqua ammonia pump 11 for being external in the dedusting pond；The dedusting pond with It is connected by drain pump 22 and pipeline between the desulfurization pond；

Flue gas enters shaped Venturi dedusting tower 30 and after preliminary desulfurization and dedusting, and entrance clear water spray column 13 completes two-grade desulfurizing and removes Dirt is processed and while realizes the ammonia process of desulfurization in the presence of outside ammonia, the ammonium sulfite of generation or bisulfite ammonia are with two grades Desulfurization and dedusting water by drain pump 22 import desulfurization pond in, with first grade desulfurizing water in dust removal in Calcium Carbonate, calcium oxide, magnesium oxide Generation regenerative response, reduces the usage amount of calcium class material.

Add coal consumption in two-grade desulfurizing dust arrester（Ton）3% ammonia of ＜ as two grades of water circulation desulfurizing agents, remove one After level dust arrester is processed, remaining micro SO2 and NO2 realizes ensureing flue dust qualified discharge while complete desulfurization.

The circulation line of the first grade desulfurizing dust arrester includes to supply to the shaped Venturi dedusting tower 30 via desulfurization water pump 8 First pump tubing length 6 of water, and first for being connected between 30 outlet of shaped Venturi dedusting tower and the desulfurization pond Reflux pipe 7；The circulation line of the two-grade desulfurizing dust arrester is included via dedusting water pump 10 to the clear water spray column 13 The second pump tubing length 8 for supplying water, and second for being connected between 13 outlet of clear water spray column and the dedusting pond Reflux pipe 9.

The desulfurization pond includes first grade desulfurizing pond 1, the two-grade desulfurizing pond 2 and three that disclosure satisfy that overflowing precipitation step by step Level desulfurization pond 3；The dedusting pond includes primary dust removing pond 4 and the two-stage dust removal pond that disclosure satisfy that overflowing precipitation step by step 5.

The clear water spray column 13 includes tower body, and is installed on inside tower body, for realizing spray filtering from top to bottom One-level spreaded type flow distribution plate 19 and two grades of spreaded type flow distribution plates 20, the one-level spreaded type flow distribution plate 19 and described two grades tiling Down current arrangement has the centrifugal type flue dehydration consistent with flow of flue gas direction of one group of spray direction respectively on the top of formula flow distribution plate 20 Spray equipment 21, water in dust removal is first dehydrated 21 spraying and dedusting of spray equipment through centrifugal type flue after clear water spray column 13 is entered, and The spreaded type flow distribution plate through bottom of taking advantage of a situation afterwards is filtered.

The centrifugal type flue dehydration spray equipment 21 includes to receive the horizontal shower of outside water in dust removal, and longitudinal cloth Located at the SMP nozzle 21-1 of the horizontal shower bottom, by support 21-2 in the jet front end of the SMP nozzle 21-1 Receded disk impeller 21-3, the receded disk impeller 21-3 are installed be installed on the support 21-2 by rolling bearing 21-4, The receded disk impeller 21-3 is more than 20cm apart from the distance between described SMP nozzle 21-1 jet；The receded disk impeller 21-3 uses plastic impeller.

The shaped Venturi dedusting tower 30 of the first grade desulfurizing dust arrester is connected with outside chain furnace 31 via economizer 32； After 31 combustion product gases of chain furnace have passed through ammonia-method denitration handling process in body of heater, warp enters first grade desulfurizing dust removal process by flue Technique；The ammonia-method denitration processing meanss include：The Calcium Carbonate for installing additional above the coal seam in the body of heater of the chain furnace 31 adds Plus groove 29, Calcium Carbonate is added to above coal seam by which；Inwardly install in high-temperature region of the furnace body temperature more than 200 DEG C and add ammonia Or the ammonia vessel 28 of carbamide, the ammonia vessel 28 is connected by the pipeline ammonia water tank 12 external with two-grade desulfurizing dust arrester, Ammonia is extracted and via in Pipeline transport to the ammonia vessel 28 by aqua ammonia pump 11；The carbamide can be directly by opening in body of heater If manhole add.By the ammonia in ammonia vessel 28 or Urea Evaporation, the interpolation of ammonia is realized.

Catalysis Principles conversion NO being realized with ammonia or carbamide cooperation by the Calcium Carbonate for adding 1-5% in chain furnace is NO2.

The main technical principle of the present invention be coordinated in stove using Calcium Carbonate and ammonia or carbamide remove nitric oxide and After sulfur dioxide, by two-stage wet method sulphur removing and dust removing technology, using the ammonia harmless and gaseous state of this material in wet flue gas are processed The low feature of inversion temperature, replaces existing conventional sodio composition double alkali method desulfurizing technology.The present invention effectively reduces existing wet method and takes off In sulfur technology, the impact of desulphurization denitration solid-state product and solute to flue dust simultaneously effectively reduces flue gas moisture content, so as to realize burning Waste gas minimum discharge.There is provided a kind of not only economical but also existing wet desulphurization denitrating technique can be suitable for, reduce the final of desulphurization denitration Product.

Description of the drawings

Fig. 1：The double wet process of FGD dust removal process process structure schematic diagrams of the present invention；

Fig. 2：Centrifugal type flue dehydration spray equipment structural representation in Fig. 1；

Fig. 3：Denitrification process principle analysis figure.

Specific embodiment

Below accompanying drawing 1-2 is described in detail below to two-stage wet process of FGD dust removal process technique of the present invention.

, embodiment

Embodiment 1

Double wet process of FGD dust removal process techniques, its structure includes：The one-level for carrying out first grade desulfurizing dust removal process to flue gas takes off Sulfur dust arrester；The two-grade desulfurizing dust arrester of two-grade desulfurizing dust removal process is carried out to the flue gas after first grade desulfurizing dust removal process； And be external in the two-grade desulfurizing dust arrester and participate in the ammonia adding set of the ammonia process of desulfurization；

Wherein, the first grade desulfurizing dust arrester includes shaped Venturi dedusting tower 30, composition desulfurization pond and step by step overflowing precipitation First grade desulfurizing pond 1, two-grade desulfurizing pond 2 and three-level desulfurization pond 3, and via desulfurization water pump 8 to the shaped Venturi dedusting The first pump tubing length 6 that tower 30 supplies water and be connected to 30 outlet of shaped Venturi dedusting tower and the three-level desulfurization pond 3 it Between the first reflux pipe 7；The two-grade desulfurizing dust arrester includes clear water spray column 13, constitutes desulfurization pond and overflow step by step The primary dust removing pond 4 of precipitation and two-stage dust removal pond 5, and supply water to the clear water spray column 13 via dedusting water pump 10 Second pump tubing length 8 and the second reflux pipe being connected between 13 outlet of clear water spray column and primary dust removing pond 4 9.The clear water spray column 13 of the shaped Venturi dedusting tower 30 of the first grade desulfurizing dust arrester and the two-grade desulfurizing dust arrester it Between be connected by top, to constitute the double wet tower structure of n shape；The ammonia adding set includes to be external in the dedusting pond Ammonia water tank 12 and aqua ammonia pump 11；By drain pump 22 and pipeline between the primary dust removing pond 4 and the three-level desulfurization pond 3 It is connected；

Flue gas enters shaped Venturi dedusting tower 30 and after preliminary desulfurization and dedusting, and entrance clear water spray column 13 completes two-grade desulfurizing and removes Dirt is processed and while realizes the ammonia process of desulfurization in the presence of outside ammonia, the ammonium sulfite of generation or bisulfite ammonia are with two grades Desulfurization and dedusting water by drain pump 22 import three-level desulfurization pond 3 in, with first grade desulfurizing water in dust removal in Calcium Carbonate, calcium oxide, There is regenerative response, further desulphurization denitration in magnesium oxide.

Embodiment 2

The present embodiment is with the difference of embodiment 1：

The shaped Venturi dedusting tower 30 of the first grade desulfurizing dust arrester is connected with outside chain furnace 31 via economizer 32；Chain After the flue gas that the burning of stove 31 is produced have passed through ammonia-method denitration handling process in body of heater, warp enters one-level by flue and economizer 32 Desulfurization and dedusting handling process；The ammonia-method denitration processing meanss include：Install additional above the coal seam in the body of heater of the chain furnace There is Calcium Carbonate adding trough 29, Calcium Carbonate is added to above coal seam by which；Furnace body temperature more than 200 DEG C of high-temperature region install to The interior ammonia vessel 28 for adding ammonia or carbamide, the ammonia vessel 28 is by the pipeline ammonia water tank external with two-grade desulfurizing dust arrester 12 are connected, and extract ammonia and via in Pipeline transport to the ammonia vessel 28 by aqua ammonia pump 11；The carbamide directly can lead to Cross the manhole for opening up in body of heater to add.

, experimental example

Material prepares：

Test coal：Low heat valve 5000cal/g；Volatile matters 28.32%；Full sulfur 0.6%；Full water 13.25%；

The ammonia of concentration 25%：6T；

Limestone:1 ton（200 mesh）Calcium oxide：1 ton（Calcium content ＞ 80%）Magnesium oxide：1 ton（Content of magnesium ＞ 75%）Egg shell：1 ton （Calcium carbonate content ＞ 80%）

Boiler model：Traveling-grate stoker quick-filling hot water boiler（DZL4.2-1.0/110/70-AII）；

Shaped Venturi dedusting tower：HSCL desulfurizing water dust scrubber（HSCL1-365T/H）；

Clear water spray column：Using the clear water spray column in embodiment 1

Demister

Testing instruments：The parallel automatic flue dust of WJ-60B type pitot tube, oil sample sampler（The limited public affairs of Qingdao City's Laoshan District electronic machine Department）.

Operating process：Start the desulfurization water pump 8 being connected with first grade desulfurizing pond 1, start and be connected with two-stage dust removal pond 5 Dedusting water pump 10, starting trouble draws, pressure fan, boiler grate make boiler runs at full capacity, and adjustment combustion chamber draft is to -30Pa.

Original determine initial SO₂=832mg/m³, 104 mg/m of NO=³, NO₂= 237 mg/m³, flue dust=1360 mg/m³

Experimental example 1

Using egg conch meal+ammonia denitration（Dry method）Calcium oxide+ammonia desulfurization（Wet method）

Tile in the Calcium Carbonate adding trough 29 on the new coal area coal seam top of boiler Calcium Carbonate, and the consumption ＞ 1% of the Calcium Carbonate is used Coal amount（By mass percentage）；Porous calcium class material after high-temp combustion in burner hearth, through the calcium sulfate portion that calcining is produced Divide the double wet tower that the present invention is entered after being converted into calcium oxide with blower fan；Measure in experiment ature of coal in the present embodiment：Work as interpolation During 1% Calcium Carbonate, SO₂It is reduced to 360 mg/m³.NO is reduced to 105 mg/m³, NO₂It is reduced to 160 mg/m³.In boiler 200- 25% ammonia 5L/h of ＞ is put in ammonia vessel 28 at 300 DEG C of temperature spots.NO is reduced to 70mg/m³, NO₂It is reduced to 132mg/m³.

Continuing quick lime is added in first grade desulfurizing pond 1, the pH value in first grade desulfurizing pond is adjusted to ＞ 6 by 3, is transported After row 20min, SO₂It is reduced to 236mg/m³.NO is reduced to 62mg/m³, NO₂It is reduced to 136mg/m³.

Aqua ammonia pump 11 is opened, makes ammonia that the entrance of the dedusting water pump 10 in two-stage dust removal pond 5 is pumped into, flow-control exists After 25L/h, 20min, SO₂It is reduced to 135mg/m³.NO is reduced to 47mg/m³, NO₂It is reduced to 126mg/m³.Start primary dust removing Clear water reserviors drain pump 22 on pond 4, primary dust removing pond 4 is contained within the water injection three-level desulfurization pond 3 of sulfurous acid ammonia.? The double alkali method desulfurizing denitration of quick lime and sulfurous acid ammonia is formed in one-level shaped Venturi dedusting tower in spray.After 20min, SO₂Reduce To 83mg/m³.NO is reduced to 51mg/m³, NO₂It is reduced to 115mg/m³.

Flue dust：25mg/m³Measurement with wet moisture content：0.8%

Experimental example 2

Tile in the Calcium Carbonate adding trough 29 on the new coal area coal seam top of boiler Calcium Carbonate, and the consumption ＞ 5% of the Calcium Carbonate is used Coal amount（By mass percentage）；Porous calcium class material after high-temp combustion in burner hearth, through the calcium sulfate portion that calcining is produced Dividing after being converted into calcium oxide desulfurizing tower is entered with blower fan；Measure in experiment ature of coal in the present embodiment when 5% Calcium Carbonate of interpolation When, SO₂It is reduced to 360 mg/m³.NO is reduced to 105 mg/m³, NO₂It is reduced to 160 mg/m³.

25% ammonia 30L/h of ＞ is put in the ammonia vessel 28 at 200-300 DEG C of temperature spot of boiler.NO is reduced to 40mg/ m³, NO₂It is reduced to 93mg/m³.

Continue calcium oxide to be added in first grade desulfurizing pond 1, the water ph value in first grade desulfurizing pond is adjusted to ＞ 6 by 3, After operation 20min, SO₂It is reduced to 120mg/m³.NO is reduced to 35mg/m³, NO₂It is reduced to 48mg/m³.

Aqua ammonia pump 11 is opened, makes ammonia that the entrance of the dedusting water pump 10 in two-stage dust removal pond 5 is pumped into, flow-control exists After 120L/h, 20min, SO₂It is reduced to 0mg/m³.NO is reduced to 17mg/m³, NO₂It is reduced to 26mg/m³.Start primary dust removing water Clear water reserviors drain pump 22 on pond 4, primary dust removing pond 4 is contained within the water injection three-level desulfurization pond 3 of sulfurous acid ammonia.One The double alkali method desulfurizing denitration of calcium oxide and sulfurous acid ammonia is formed in level Water spray.Reduce ammonia dosage to 5 L/h, 20min Afterwards, SO₂Keep to 0mg/m³.NO is reduced to 12mg/m³, NO₂It is reduced to 18mg/m³.

Flue dust：28mg/m³Measurement with wet moisture content：0.8%

Experimental example 3

Using egg conch meal+carbamide denitration（Dry method）Magnesium oxide+ammonia desulfurization（Wet method）

Tile in the Calcium Carbonate adding trough 29 on the new coal area coal seam top of boiler Calcium Carbonate, and the consumption ＞ 1% of the Calcium Carbonate is used Coal amount（By mass percentage）；Porous calcium class material after high-temp combustion in burner hearth, thinner passes through the sulfur that calcining is produced Sour calcium enters desulfurizing tower with blower fan after being partially converted into calcium oxide；Measure in experiment ature of coal in the present embodiment when 1% carbon of interpolation During sour calcium, SO₂It is reduced to 360 mg/m³.NO is reduced to 105 mg/m³, NO₂It is reduced to 160 mg/m³.

Carbamide 15L/h is put in the ammonia vessel 28 at 200-300 DEG C of temperature spot of boiler.NO is reduced to 76mg/m³, NO₂Drop As little as 122mg/m³.

Continue magnesium oxide to be added in first grade desulfurizing pond 1, the water ph value in first grade desulfurizing pond 1 is improved to ＞ 6 by 3, After operation 20min, SO₂It is reduced to 110mg/m³.NO is reduced to 33mg/m³, NO₂It is reduced to 43mg/m³.

Aqua ammonia pump 11 is opened, makes ammonia that the entrance of the dedusting water pump 10 in two-stage dust removal pond 5 is pumped into, flow-control exists After 25L/h, 20min, SO₂It is reduced to 135mg/m³.NO is reduced to 47mg/m³, NO₂It is reduced to 126mg/m³.Start primary dust removing Clear water reserviors drain pump 22 on pond 4, primary dust removing pond 4 is contained within the water injection three-level desulfurization pond 3 of sulfurous acid ammonia.? The double alkali method desulfurizing denitration of quick lime and sulfurous acid ammonia is formed in one-level Water spray.After 20min, SO₂It is reduced to 83mg/m³.NO drops As little as 51mg/m³, NO₂It is reduced to 115mg/m³.

Flue dust：5mg/m³Measurement with wet moisture content：0.8%

Experimental example 4

Carbamide 120L/h is put in the ammonia vessel 28 at 200-300 DEG C of temperature spot of boiler.NO is reduced to 37mg/m³, NO₂ It is reduced to 86mg/m³.

Continue magnesium oxide to be added in first grade desulfurizing pond 1, the water ph value in first grade desulfurizing system is adjusted to ＞ 6 by 3, After operation 20min, SO₂It is reduced to 17mg/m³.NO is reduced to 6mg/m³, NO₂It is reduced to 12mg/m³.

Aqua ammonia pump 11 is opened, makes ammonia that the entrance of the dedusting water pump 10 in two-stage dust removal pond 5 is pumped into, flow-control exists After 120L/h, 20min, SO₂It is reduced to 0mg/m³.NO is reduced to 8mg/m³, NO₂It is reduced to 7mg/m³.Start clear water reserviors drain pump 22, the water injection three-level desulfurization pond 3. that primary dust removing pond 4 is contained within sulfurous acid ammonia forms oxidation in one-level Water spray The double alkali method desulfurizing denitration of calcium and sulfurous acid ammonia.Reduce ammonia dosage to 5 L/h, 20min, SO₂Keep to 0mg/m³.NO It is reduced to 10mg/m³, NO₂It is reduced to 11mg/m³.

Flue dust：7mg/m³Measurement with wet moisture content：0.8%

Experimental example 5

Using egg conch meal+carbamide denitration（Dry method）Limestone+ammonia desulfurization（Wet method）

Tile in the Calcium Carbonate adding trough 29 on the new coal area coal seam top of boiler Calcium Carbonate, and the consumption ＞ 5% of the Calcium Carbonate is used Coal amount（By mass percentage）；Porous calcium class material after high-temp combustion in burner hearth, through the calcium sulfate portion that calcining is produced Dividing after being converted into calcium oxide desulfurizing tower is entered with blower fan；Measure in experiment ature of coal in the present embodiment when 1% Calcium Carbonate of interpolation When, SO₂It is reduced to 360 mg/m³.NO is reduced to 105 mg/m³, NO₂It is reduced to 160 mg/m³.

Carbamide 120L/h is put in the ammonia vessel 28 at 200-300 DEG C of temperature spot of boiler.NO is reduced to 45mg/m³, NO₂ It is reduced to 79mg/m³.

Continue 200 mesh limestone are added in first grade desulfurizing pond 1, the water ph value in first grade desulfurizing system is adjusted by 3 To ＞ 6, after running 20min, SO₂It is reduced to 52mg/m³.NO is reduced to 6mg/m³, NO₂It is reduced to 26mg/m³.

Aqua ammonia pump 11 is opened, makes ammonia that the entrance of the dedusting water pump 10 in two-stage dust removal pond 5 is pumped into, flow-control exists After 120L/h, 20min, SO₂It is reduced to 0mg/m³.NO is reduced to 17mg/m³, NO₂It is reduced to 17mg/m³.Start clear water reserviors emptying Pump 22, the water injection three-level desulfurization pond 3. that primary dust removing pond 4 is contained within sulfurous acid ammonia forms oxygen in one-level Water spray Change the double alkali method desulfurizing denitration of calcium and sulfurous acid ammonia.Reduce ammonia dosage to 5 L/h, 20min, SO₂Keep to 0mg/m³. NO is reduced to 17mg/m³, NO₂It is reduced to 11mg/m³.

Flue dust：27mg/m³Measurement with wet moisture content：0.8%

3rd, the present invention program thinking and design principle analysis

It is an object of the invention to reducing in existing Wet Flue Gas Desulfurization Technique, the impact of desulphurization denitration solid-state product and solute to flue dust And effectively reduce flue gas moisture content, so as to realize burning waste gas minimum discharge.There is provided a kind of not only economical but also can be suitable for existing wet Method desulfurizing and denitrifying process, reduces the final product of desulphurization denitration.

The invention mainly includes coordinate in stove using Calcium Carbonate and ammonia or carbamide removing NO and NO₂Afterwards, by n Type two-stage wet method sulphur removing and dust removing technology, filters the flue dust for carrying in one-level water in wet flue gas are processed using two-stage dust removal device With desulfurization belongings.And using the harmless and low feature of gaseous state inversion temperature of this material of ammonia, replace in primary dust removing device existing Conventional sodio composition double alkali method desulfurizing technology.

Plan explanation

1st, according to chain furnace structure and combustion stablized burning feature, Calcium Carbonate is added in coal seam, adds in high-temperature flue gas area of Hou Qiang area Entering ammonia vessel, making the ammonia of injection or carbamide that tail flue gas are entered in the form of volatilizing, combination completes smoke catalytic denitration.

2nd, water smoke intercepts dust collecting process

The moisture content of 8-12% can be carried in the flue gas after shaped Venturi dedusting tower first grade desulfurizing dedusting（Contain dust in moisture content and take off Sulfur denitration product）With part fine dust, by using two grades of sprays in clear water spray column plus tiling flow distribution plate filtration, enter one Step is collected one-level dust-containing water and removes untreated fine dust.Wherein, in the nozzle of spreaded type flow distribution plate top down current arrangement The current of nozzle are increased further by atomizing effect using centrifugal rotational flow blade.

3rd, ammonia process of desulfurization backflow is recycled

It is ammonium sulfite, not affect final soot emissions to be worth principle, in two-grade desulfurizing dedusting work using ammonia process of desulfurization formation Ammonia process, the ammonium sulfite of formation or ammonium bisulfite is adopted to be flowed back in importing first grade desulfurizing dust collecting process again in skill, de- with one-level Calcium Carbonate, calcium oxide, magnesia FGD denitration in sulfur dust collecting process, merges the double alkali method desulfurizing technology for forming ammonia process technique.

Handling process in detail is as follows：

Flue gas flow：Boiler（Calcium Carbonate adding set, ammonification groove）- economizer-venturi water film deduster-clear water spray column- Clear water deentrainment tower-air-introduced machine-chimney.

Fine dust is completed using hydraulic art and desulfurization product dilution is intercepted：

1）Two grades of hydraulic arts complete fine dust interception

By early stage testing results, in one-level shaped Venturi dedusting tower, the moisture content of flue gas is 8-12%, wherein to contain particulate pollutant About 70-120 mg/m³, the main cause for producing this partial contamination thing mainly has at 2 points：1st, the fine solid particle not removed.Actual measurement About 30 mg/m³；2 desulphurization denitration products.Actual measurement is about 60 mg/m³.

For existing 20 mg/m of flue dust ＜³Require, devise two grades of water treatment technologies, main technique includes：Using 1 Dedusting water pump 10 extracts clear water in two-stage dust removal pond 5, enters clear water spray column 13, enters the water in dust removal quilt of clear water spray column Spreaded type flow distribution plate is cut into mist droplet, with one-level shaped Venturi dedusting tower process complete containing part fine solid particle and take off The flue gas of sulfur denitration product is fully collided, and after carrying out interception mixing, is emitted in primary dust removing pond 4, is removed to two grades after precipitation In dirt pond 5, recycle.When turbidity is exceeded, in being drawn water to three-level desulfurization pond 3 using clear water reserviors drain pump 22.

2）Application of the centrifugal impeller in water treatment technology

In the middle of Water spray technique, the pressure of water is higher, and the discharge area of nozzle is less, and the atomizing effect of spray is also less, But in industrial smoke handling process, as water must be recycled, so desulfurization and dedusting water turbidity is all higher than 2NTU, have In grey black.Also droplet also can only achieve 700 microns to the best SMP nozzle of atomizing effect now.According to blower fan spiral shell The principle of rotation oar rotation, more liquid（High flow rate）Airflow function under, the blade of rotation can be formed by air-introduced machine Kinetic energy, well by nozzle spray water smoke break up.And the particulate matter baffling in air-flow slows down, it is fully contacted with water.（See Fig. 2：Following current nozzle adds propeller）It is found through experiments：During dedusting hydraulic pressure ＞ 0.35MPa, when helical blade is apart from nozzle 10cm, As current do not scatter completely, its atomizing effect is poor, under water impact, serves the effect for preventing dispersion of flow.Two Secondary mounting distance nozzle 15cm, can be with divergent flow.After ＞ 20cm is reached apart from spray site, its jet angle dissipates completely Open, impeller serves good atomization and mixed effect.When the final discharge value of its flue dust does not install impeller additional, decline 8 mg/m³.

Centrifugal type flue dehydration spray equipment mainly includes：SMP nozzle, connecting bracket, rolling bearing, impeller（Plastics）. As impeller is run in flue, equivalent temperature is although relatively low, but which needs to stand the impingment corrosion of acid and alkali corrosion, water droplet, in work In journey, the rotatable parts such as impeller, bearing are all made using 2205 or 316L rustless steels, prevent the wear and tear excessive impeller for causing and axle Hold damage.

In the present invention, two groups of downward nozzles, down current arrangement nozzle, flow of flue gas direction are disposed with clear water spray column It is identical with water-jet direction, that is to say, that only the speed difference of reliable current and air-flow collides,（Flue gas is water as density is little The decades of times of flow velocity degree）Realize dedusting.It is the excessively poor main cause of dust removing effects that the bad and collision ratio of atomizing effect is too small.

Double alkali method desulfurizing is completed using two-stage Water spray technique：

1）Primary dust removing sulfur removal technology

In first grade desulfurizing dust removal process technique, main task is desulphurization denitration and rough dusting.Desulfurization water pump 8 is from first grade desulfurizing Draw water in pond 1 to trunnion spray and the cannelure spray of shaped Venturi dedusting tower, remove in flue gas according to the principle of centrifugal dust-removing Bulky grain flue dust, meanwhile, add the lime slurry being stirred in first grade desulfurizing pond 1（Calcium hydroxide）, using the stone for adding The calcium class material for remaining in grey serosity and part lime-ash and SO₂And NO_XReact, three-level desulfurization is back to by reflux pipe Pond 3, after precipitating step by step, enters first grade desulfurizing pond 1 and recycles.

2）Ammonia desulfurization is added in two grades of water：

Hydroxide ion be to the SO in flue gas₂And NO_XProcess most effective way.In first grade desulfurizing dust removal process technique, Hydroxyl flue gas is carried using metal ion to be processed.Actual measurement desulfuration efficiency is about 75-85%, first grade desulfurizing dust removal process work SO in skill₂Final discharge value is in 130-180mg/m³, SO₂Disclosure satisfy that existing standard requirement.

In order to reduce the discharge of pollutant further.In two-grade desulfurizing dedusting treater, it is provided with ammonia and adds system System.It is found by experiment that, the volatile flavor of ammonium sulfite can be accepted by the public in the case of 80 DEG C of ＜.And ammonium sulfite Do not count in the discharge of smoke contamination thing.That is the desulfurization product that ammonification is formed will not adopt weight to flue dust Produce impact.In the present invention, ammonia is positioned over ammonia water tank（12）, using aqua ammonia pump（11）Add to two grades of clarified water pumps（9、10）Enter Mouthful, as dedusting pond is that open arrangement, ammonia is directly injected at pump intake to be prevented from leaking.

Completely using ammonia desulfurization greatest problem be ammonia escapement ratio too high, the ammonia of escape not only causes the profit of ammonia Reduced with rate, and nearby resident can smell ammonia taste to cause heating plant.It is found by experiment that in the long-term not desulfurization of water In the case of, the pH value of water is 2.5 or so.In the middle of this technique, the SO of two-grade desulfurizing dust arrester is entered₂Amount is very little, in order to Guarantee the maximization of efficiency of dust collection, its design spray area reaches 400%.As long as so the pH value of water is slightly improved to ＞ 3, Substantially can be gone out remaining SO₂.When pH value controls to 5-6, its SO₂Final discharge value can reach 15 mg/m of ＜³, when in water When pH value is to ＞ 7, in environment, ammonia abnormal smells from the patient substantially increases.

Conclusion 1：By adding ammonia on a small quantity in two-stage dust removal, the SO of low concentration in flue gas can be disposed₂And will not Environmental air pollution is caused to environment.

3）Ammonium method regenerative response：

The long-term ammonium sulfite for adding ammonia formation is stepped up in two grades of ponds, due to being continuously increased of solute in solution, gesture The output drop of water pump must be caused, while also have being dispersed in the air on a small quantity.Cause ammonia taste heavier.（In common process, it is Its product is treated as chemical fertilizer.）

Metal ion in primary dust removing sulfur removal technology（Calcium oxide, Calcium Carbonate, magnesium oxide）Need by regeneration technology ability Desulfuration efficiency is enough improved（It is to use sodium hydroxide as regenerative agent in conventional Dual alkali technique）, reduce simple alkalinous metal desulfurization Usage amount, improve response speed.

In technique, in first grade desulfurizing system operation, startup optimization clear water reserviors drain pump 22, the water containing ammonium sulfite Enter first grade desulfurizing system circulation and complete regenerative response.While cell body is filled using life water.Two grade water-soluble matter are completed Reduce and the regeneration reducing of low-level culture pool reacts.

The system process of chain-grate boiler ammonia-method denitration：

Ammonia denitration is the Main Means in denitrating technique, and it is major control work to use spray ammonia in catalytic control technique Skill, after spraying ammonia system complex process and spraying into ammonia in chain furnace, is urged using noble metals such as vanadic anhydrides in back segment Change.As the response time is too short, can cause to crystallize near economizer.With process is simple, but system complex, denitration high cost.

According to chain furnace features of oven profile, the wherein lime-ash of 70-80% is discharged by slag remover.The cigarette for containing in flue gas Dirt about 1300-1500 mg/m³.Chain furnace coal is added water in advance, and flue gas itself water vapour accounts for 10-20%.

According to the burning feature of chain furnace, so the increase of moisture content is no affected on burning, its coal is to complete combustion on fire grate Burn.So unlike pulverized-coal fired boiler has the risk of fire extinguishing.

In nitrogen oxides, main component is divided into NO and NO₂, in the central NO*1.5+NO of detection₂=NO_X.

1)NO₂Removal analysis

NO₂Dissolubility height in water, from the Alkali absorption NO of ammonia and calcium hydroxide₂.It is all to be directly translated into gaseous state Material.A correct position and suitable temperature spot placement part ammonia is selected just can effectively to make ammonia with NO₂Occur Redox reaction.

In this engineering, ammonia and calcium hydroxide is employed（CaO）Used as sulfur removal technology, primary dust removing pH value controls 7-9. PH value control 3-6 in secondary amine water desulfurization industry.Removal major part NO can be merged in sulfur removal technology₂

2) nitric oxide（NO）Removal analysis

The removal of NO needs to use NO and is catalyzed containing oxidized metal, and NO is become NO by metal catalytic oxidation₂, then with absorption Or solution absorption process removes NO again₂, precious metal catalyst effect is good, but expensive.Although calcium oxide and Calcium Carbonate catalysis effect Fruit not as vanadic anhydride etc. substantially, but as long as increasing the ratio of calcium oxide and Calcium Carbonate in flue gas, can equally play promotion The effect of NO oxidation.

According to denitrogenation flue gas treating process flow process, utilize《Layer burning stove desulfurization removing nitric flue gas treating process》 ZL201410137998X principle, in coal seam top tiling 2-5mm egg shell mixture, just has substantial amounts of egg in such flue gas The Calcium Carbonate that conch meal is formed（CaCO₃）And calcium oxide（CaO）, metal-oxide is when temperature is higher than 250 DEG C to NO catalysis oxygen Changing has certain activity.The maximum temperature point of chain furnace is on the top of fire grate, is 1500 DEG C, as flue gas stream is through water-cooled Gradually reduce after wall, furnace tube, furnace arch, furnace nose to 300-400 degree Celsius.Through high-temperature region oxidation nitric oxide（NO）Most of Generate nitrogen dioxide（NO₂）, in about 350 DEG C of temperature spots（Afterbody deashing is checked near population installs an ammonia vessel and ammonification pump Outlet connection, adds the ammonia of ammonia vessel to evaporate under the photothermy of high-temperature flue gas, quickly in flue gas.Ammonia and nitrogen Optimal mixing temperature point is 150 DEG C of ＞.Ammonia（NH₃）With NO₂Neutralization in various alkaline matters preferably, to flue dust Impact coefficient minimum.After the gas mixings such as nitrogen oxides and sulfur dioxide in the ammonia being evaporated and flue gas, by follow-up two Level water treatment facilities cooling is intercepted, and ammonium nitrate and remaining alkaline matter have been returned to complete denitration in desulfurization pond and dedusting pond Technique.

Double wet method sulphur removing and dust removing technology methods are discussed

Adopting Dual alkali（Quick lime+sodium hydroxide）Primary dust removing desulfurizing tower is exported, and dust concentration is 70-100 mg/Nm³, SO₂170 mg/Nm of ＜³, NO_X250 mg/Nm of ＜³.

In two grades of wet dedusting areas, by using ammonia as desulfurization denitrification agent, NH₃·H₂O + SO₂→NH₄HSO₃, shape The ammonium sulfite for becoming or ammonium bisulfite（Liquid）3 three-level desulfurization ponds are switched by 22 clear water reserviors drain pumps again and form secondary profit With.

Ca(OH)₂+(NH₄)SO₃→CaSO4+2NH₄▪OH

Ca(OH)₂+NH₄HSO₃→CaSO₃+NH4·OH+ H₂O

2NH₄·OH + SO₂→(NH₄)SO₃+ H₂O

NH₄OH+SO₂→NH₄HSO₃

The advantage of sodium sulfite is replaced with ammonium sulfite,

In sodium alkali sulfur removal technology, in flue gas, the exceeded material of flue dust is caused for salts substances using middle its maximum of discovery.Sodium With the difference of ammonium salt, salt is that property is different, in flue gas band regimen condition be inevitable, but in flue gas after desulfurization carry material It is ammonium salt（Ammonium sulfite）, it is harmless to environment, falls in soil and be additionally favorable for plant growing.And sodium salt（Sodium sulfite）With cigarette Gas is discharged in the air, and not only sucking causes resistance of human body to decline, fall into the salinization for also resulting in soil in soil in vivo.

According to GB/T16157《Particulate matter and the gaseous contaminant method of sampling in Concentration in Fixed Pollutants Source》Regulation, flue dust is existing Filter cylinder after quarry sampling, needs to carry out drying to weigh, and concrete grammar is as follows：

1) preparation of standard blank filter cylinder

The filter cylinder that buys is put in baking oven, under 105～110 DEG C of constant temperature, after drying 4 hours, places in exsiccator 2 little When, room temperature is cooled to, is put in ten thousand/gram balance and weighs, as the standard weights of standard blank filter cylinder；

2) after sampling, filter cylinder weighs

The filter cylinder after sampling being put in baking oven, under 105～110 DEG C of constant temperature, after drying 4 hours, places into 2 in exsiccator Hour, room temperature is cooled to, is put in ten thousand/gram balance and weighs.Now, after sampling filter cylinder and standard blank filter cylinder weight Quasi- heavy phase is poor, is the final weight of flue dust.

By to filter cylinder analysis method of sampling to analysis, 105 DEG C is analysis temperature point, that is to say, that can to less than 105 DEG C Moisture with removal etc. is not intended as particulate pollutant.Decompose on impact can be produced on air quality after the suction such as calcium, magnesium, carbon, salt Pollutant o'clock more than 105 DEG C are accordingly to be regarded as flue dust.Although sodium sulfite and ammonium sulfite are all transparent liquid, but which decomposes temperature Degree has very big difference, and sodium sulfite, calcium, magnesium etc. all can be decomposed into gaseous state at 1500 DEG C or so, and the gaseous state transfer point of ammonium is 150 ℃.

But it is found by experiment that：The characteristic of ammonium material but the decomposition temperature of ammonium sulfite can start conversion at 77 DEG C For gaseous state, Huawei's gaseous state can be risen rapidly at 150 DEG C.Result of the test is as follows：

Carbon ammonium, ammonium sulfite, three kinds of ammonium materials of carbamide are taken in constant temperature oven,（Carbon ammonium 6.9151g, ammonium sulfite 20.6082g, carbamide 20.1729g）.First temperature is set to 77 DEG C, after 1 hour, three kinds of substance weights are unchanged.It is increased to 105 DEG C,（Carbon ammonium 2.0276g, ammonium sulfite, 5.7971g, carbamide 20.3139g）.The weight of carbon ammonium and ammonium sulfite is significantly Decline, carbamide is unchanged.It is placed again into constant temperature oven and 3 hours is dried,（Carbon ammonium 0.0231g, ammonium sulfite, 0.8276g, carbamide 20.3065g）.

The low-temperature stability test of ammonium sulfite

Ammonium is a kind of unstable salt.Readily volatilized.In desulfurization and dedusting water, there is volatilization.Excessive concentration can be led Cause nearby to distribute unpleasant ammonia abnormal smells from the patient.In order to ensure the ammonium sulfite of liquid can be stable be present in water.Asia is carried out The heat run of ammonium sulfate.

21g ammonium sulfite is positioned over 60 DEG C of baking ovens of constant temperature, is heated 2 hours, volatilize 0.279g.70 DEG C are continuously heating to, Volatilized after two hours 1.275g, is warming up to 80 DEG C, and volatilized after two hours 2.683g；90 DEG C are warming up to, are volatilized after two hours 4.572g.

Proved by test：Desulfurization water temperature control below 60 DEG C when, ammonium sulfite is substantially at steady statue, subsequently by Step volatilization, the higher evaporation rate of temperature is faster.

Illustrated by above-mentioned test:Desulfurization water temperature controls below 70 DEG C, and distributing for its ammonium is permissible to public's environmental effect Receive.The ammonium sulfite that ammonia process of desulfurization denitration is formed no is affected on the discharge value of flue dust.

In conventional desulfurization denitrating technique, it is used for preparing fertilizer using the ammonium sulfite after desulphurization denitration.In this engineering, Once desulfurization pond added with lime water squeezed into again by the ammonium sulfite that secondary desulfuration is formed, and is mixed to form new with hydroxide Double alkali method desulfurizing technology based on calcium, supplemented by ammonium sulfite.

Its main advantage is, in first grade desulfurizing dedusting, forms main desulphurization reaction, the desulfurization product being carried out and surplus Remaining flue dust carries out process in two-stage dust removal and completes, remaining a small amount of SO₂And NO_XSynthesis is carried out using ammonia.As low ammonia is low, PH value, big yield just improve the utilization rate of ammonia, reduce the escapement ratio of ammonia.

Technical essential：

1) using the construction featuress of chain furnace, coal seam top is anti-using catalysis is realized after eggshell or shell burning in the chain-grate boiler Should, then ammonia is put in the high-temperature region of 200 DEG C of ＞ or carbamide removes NO and NO₂.Five are replaced to aoxidize using Calcium Carbonate or calcium oxide The noble metals such as two vanadium effectively reduce the catalysis cost of NO；Add ammonia or carbamide using tank high temperature evaporation, instead of now normal Ammonia principle is sprayed in atomization.Improve the utilization rate of ammonia.The process procedure of ammonia-method denitration is saved.

2) using limestone or quick lime or magnesium oxide as desulfurization thing in low-level culture pool, ammonia is used as two-grade desulfurizing Thing, the desulfurization product ammonium sulfite of two grades of pond formation is back to first grade desulfurizing pond again and forms Dual alkali.By double for traditional sodium calcium alkali Method improvement is calcium ammonium Dual alkali or magnesium ammonium Dual alkali.The desulfuration efficiency of total system is improved, in the situation of equal desulfuration efficiency, relatively Calcium method and the content for greatly reducing solute in desulfurization water of sodium method.Eventually reduce the content of flue dust in smoke evacuation.And solve Merely using the too high problem for causing periphery abnormal smells from the patient dense of ammonia process escapement ratio.

3) using double wet method structures, from the bottom to top, two grades from top to bottom for one-level.Desulfurization product and do not remove that one-level is produced Remaining fine smoke, carry out mixing flushing by two grades of shower waters and fixed plastic filler.Solve sack cleaner In the sulfur removal technology that after first dedusting, desulfurization causes, desulfurization product causes the exceeded phenomenon of flue dust.

Using a kind of new desulfurization and dedusting nozzle, before conventional desulfurization and dedusting nozzle, a leaf is installed in ＞ 15cm position Wheel.Impeller high-speed rotation under flue gas drive, the water for spraying nozzle and the flue gas for passing through at a high speed are sufficiently mixed, and increased desulfurization Water in dust removal and the contact probability of flue gas.Improve the dust-removal and desulfurizing efficiency of wet dust removal desulphurization device.

Claims

1. pair wet process of FGD dust removal process technique, is characterised by, its structure includes：

Wherein, the first grade desulfurizing dust arrester includes shaped Venturi dedusting tower, desulfurization pond and circulation line；The two-grade desulfurizing Dust arrester includes clear water spray column, dedusting pond and circulation line；The shaped Venturi dedusting tower of the first grade desulfurizing dust arrester It is connected by top and the clear water spray column of the two-grade desulfurizing dust arrester between, to constitute the double wet tower structures of n shape；

The ammonia adding set includes ammonia water tank and the aqua ammonia pump for being external in the dedusting pond；The dedusting pond with described It is connected by drain pump and pipeline between desulfurization pond；

Flue gas enters shaped Venturi dedusting tower and after preliminary desulfurization and dedusting, enters clear water spray column and completes at two-grade desulfurizing dedusting Reason simultaneously while realizes flue dust and the desulphurization denitration product that the ammonia process of desulfurization merges 10 μm of ＜ of washing, ammonia process in the presence of outside ammonia The ammonium sulfite of desulfurization generation or bisulfite ammonia and dust-laden solution import one-level with two-grade desulfurizing water in dust removal by drain pump In water circulation system, Calcium Carbonate in ammonium sulfite or bisulfite ammonia and first grade desulfurizing water in dust removal or calcium oxide or magnesium oxide are sent out Raw regenerative response, in the utilization rate for improving alkaline matter simultaneously, and rationally reduces dedusting water turbidity in two grades of water circulations.

2. double wet process of FGD dust removal process techniques as claimed in claim 1, are characterised by

The clear water spray column includes tower body, and be installed on inside tower body from top to bottom, for realizing the one-level of spray filtering Spreaded type flow distribution plate and two grades of spreaded type flow distribution plates, the one-level spreaded type flow distribution plate and two grades of spreaded type flow distribution plates upper Down current arrangement has one group of spray direction centrifugal type flue dehydration spray equipment consistent with flow of flue gas direction, water in dust removal respectively in portion After clear water spray column is entered, first spray equipment spraying and dedusting is dehydrated through centrifugal type flue, then takes advantage of a situation through the tiling of bottom Formula flow distribution plate is filtered.

3. double wet process of FGD dust removal process techniques as claimed in claim 2, are characterised by

The centrifugal type flue dehydration spray equipment includes to receive the horizontal shower of outside water in dust removal, and longitudinal direction is laid in institute The SMP nozzle of horizontal shower bottom is stated, receded disk impeller is provided with the jet front end of the SMP nozzle by support, The receded disk impeller is installed on the support by rolling bearing, and the receded disk impeller is sprayed apart from the SMP nozzle The distance between mouth is more than 20cm；The receded disk impeller uses plastic impeller.

4. double wet process of FGD dust removal process techniques as claimed in claim 3, are characterised by

Establish two independent water-flow circuits, the circulation line of the first grade desulfurizing dust arrester include via desulfurization water pump to The pump tubing length that the shaped Venturi dedusting tower supplies water, and it is connected to the shaped Venturi dedusting tower outlet and the desulfurization pond Between reflux pipe；The circulation line of the two-grade desulfurizing dust arrester is included via dedusting water pump to the clear water spray column The pump tubing length of water supply, and the reflux pipe being connected between the clear water spray column outlet and the dedusting pond；Two Level desulfation dust-extraction device processes remaining flue dust in the muddy water of primary dust removing device and flue gas.

5. double wet process of FGD dust removal process techniques as claimed in claim 4, are characterised by

Add 3% ammonia of ＜ of coal consumption in two-grade desulfurizing dust arrester as two grades of water circulation desulfurizing agents, remove primary dust removing dress Put remaining micro SO after process₂And NO₂Realize ensureing flue dust qualified discharge while complete desulfurization.

6. double wet process of FGD dust removal process techniques as claimed in claim 5, are characterised by

The desulfurization pond includes first grade desulfurizing pond, two-grade desulfurizing pond and the three-level desulfurization that disclosure satisfy that overflowing precipitation step by step Pond；The dedusting pond includes primary dust removing pond and the two-stage dust removal pond that disclosure satisfy that overflowing precipitation step by step.

7. double wet process of FGD dust removal process techniques as claimed in claim 1, are characterised by

The shaped Venturi dedusting tower of the first grade desulfurizing dust arrester is connected with outside chain furnace via economizer；Mode chain furnace combustion After flue gas have passed through ammonia-method denitration handling process in body of heater, warp enters first grade desulfurizing dust removal process technique by flue；The ammonia process Denitration treatment device includes：Calcium Carbonate adding trough is added above the coal seam in the body of heater of the chain furnace, by which to coal Layer adds Calcium Carbonate above；The ammonia vessel for inwardly adding ammonia or carbamide, institute are installed in high-temperature region of the furnace body temperature more than 150 DEG C State ammonia vessel to be connected by the pipeline ammonia water tank external with two-grade desulfurizing dust arrester, by aqua ammonia pump extract ammonia and via Pipeline transport is to the ammonia vessel；The carbamide directly can be added by the manhole for opening up in body of heater；By in ammonia vessel Ammonia or Urea Evaporation, realize the interpolation of ammonia.

8. wet process of FGD dust removal process techniques as claimed in claim 7 double, the carbonic acid being characterised by by adding 1-5% It is NO in chain furnace₂.