CN106474895A

CN106474895A - A kind of method and device of deep removal sulfureous in flue gas oxide

Info

Publication number: CN106474895A
Application number: CN201611245803.9A
Authority: CN
Inventors: 苏跃进
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-12-29
Filing date: 2016-12-29
Publication date: 2017-03-08

Abstract

The present invention relates to a kind of method and device of deep removal sulfureous in flue gas oxide, the method includes making flue gas carry out first grade desulfurizing and two-grade desulfurizing from bottom to top successively；In first grade desulfurizing, calcium carbonate serosity and flue gas carry out desulphurization reaction, after fall into the recycle slurry liquid pool of desulfurization tower bottom and circulate for first grade desulfurizing；In two-grade desulfurizing, sodio desulfurizing agent, Mg-base desulfurizing agent, potassio desulfurizing agent or calcium hydroxide are sprayed in flue gas and are carried out desulphurization reaction with solution or slurry form atomization, after fall into recycle slurry liquid pool and circulate for first grade desulfurizing；Calcium carbonate serosity is newly supplemented by adjustment, controls the pH value of loop slurry；By adjusting desulfurizing agent solution or the serosity of two-grade desulfurizing, control the sulfoxide concentration of desulfurizing tower exiting flue gas.On the basis of limestone-gypsum wet desulfuration, deep removal discharges the oxysulfide in flue gas to the method, improves the removal efficiency of sulfur trioxide in discharge flue gas, has the advantages that fast response time, degree of regulation height, regulation quality are good.

Description

A kind of method and device of deep removal sulfureous in flue gas oxide

Technical field

The invention belongs to flue gas desulfurization technique field is and in particular to a kind of method of deep removal sulfureous in flue gas oxide, Also relate to a kind of device of deep removal sulfureous in flue gas oxide.

Background technology

Flue gas desulfurization (Flue Gas Desulfuration, FGD) refers to remove from flue gas or other industrial waste gases Oxysulfide (mainly SO₂And SO₃) process.Oxysulfide in flue gas is substantially acid, can by with suitable Alkali substance reaction, generates the mixture of sulphite and sulfate, thus removing from flue gas.The most frequently used alkali of flue gas desulfurization Property material is limestone (Calcium Carbonate), quick lime (calcium oxide) and Calx (calcium hydroxide)；Limestone abundance, thus phase To cheap, quick lime and Calx are all to be produced by heating by limestone.

Limestone-gypsum Wet Flue Gas Desulfurization Process technique is a kind of most widely used at present sulfur removal technology.This technique is mainly profit With limestone cheap and easy to get as desulfurization absorbent, limestone makes Calx with water mix and blend after pulverizing and jevigating powdering Stone serosity；Lime stone slurry serosity is pumped in desulfurizing tower, lime stone slurry is mixed with smoke contacts, two in flue gas Calcium Carbonate in sulfur oxide and serosity and the oxidation air blasting carry out chemical reaction and generate calcium sulfate；In desulphurization tower slurry pool After calcium sulfate reaches certain saturation degree, form gypsum slurries and discharge.

In sulfur oxides emissions national standard, only control sulfur dioxide emissioning concentration at present, do not include sulfur trioxide row Put concentration.In the case that sulfur oxides emissions standard value is higher, the measure of conventional raising desulfuration efficiency is very economical, have Effect.The measure of the raising desulfuration efficiency commonly used at present has many kinds, including the serum recycle flow, the arrangement support that increase desulfurizing tower Disk, two-region arrangement, Two-way Cycle arrangement, double tower arrangement etc., it is relatively many for the removal efficiency raising of sulfur dioxide, for three Although the removal efficiency of sulfur oxide is improved, lift limited extent.But, when the low-down situation of sulfur oxides emissions standard value Under, for example, discharge standard value, according to " minimum discharge ", is less than 35mg/ according to combustion engine discharge standard sulfur dioxide emissioning concentration Nm³In the case of, the conventional economy of measure of raising desulfuration efficiency, effectiveness decline obvious, the desulfurization of low ph value Serosity is not so good for the removal effect of the low-down sulfur dioxide of concentration.If reducing emission standards for sulfur dioxide further Value, or have clearly relatively low discharge standard value to require for sulfur trioxide, according to the measure of conventional raising desulfuration efficiency, The cost increase reducing sulfur dioxide concentration further is relatively more, and removal effect lifting is limited, not necessarily disclosure satisfy that discharge Require, the removal effect for sulfur trioxide is very inconspicuous.

Unavoidably there is in flue gas certain sulfur trioxide concentration.Taking coal-burning power plant as a example, in flue gas, sulfur trioxide comes Mainly there are two aspects in source, and one is the sulfur dioxide that the flammable sulfur burning in coal dust produces, and this part about 0.5%-2% is by oxygen Turn to sulfur trioxide；Two is because in denitrification apparatus SCR catalyst, vanadic anhydride under the high temperature conditions, has by force to sulfur dioxide Strong catalytic action, can make the sulfur dioxide of 0.2%-0.8% be oxidized to sulfur trioxide.SCR device is for sulfur trioxide Conversion ratio there are certain requirements, usually require that less than 1%.Discounting for sulfur trioxide concentration in air preheater, dedusting The variable quantity of device link, enters in the flue gas of desulfurizing tower, the concentration of sulfur trioxide is about in 0.7%-2.8%.In general, often The removal efficiency advising Limestone-gypsum Wet Flue Gas Desulfurization Process technique for sulfur trioxide is only in 30%-50%.And sulfur trioxide is for environment The extent of injury of pollution is also far above sulfur dioxide.In the case of same concentration, the harm of sulfur trioxide is about sulfur dioxide Ten times.The concern having caused government and society is controlled for the sulfur trioxide in discharge flue gas.

Desulfurizing tower discharges the source of sulfur trioxide drop (sulfuric acid droplets) in flue gas, has a kind of explanation to be not remove clean Sulfur dioxide gas dissolve in the fine droplet that flue gas carries formation sulfurous acid, in the liquid phase, sulfurous acid and its salt are easy to It is oxidized to sulphuric acid and its salt (refers in December, 2006《Environmental protection for electric power》In, written by Lanzhou-Xinjiang life etc., " limestone/gypsum is wet SO in method desulphurization system neat stress₃The discussion that (sulfuric acid mist) originates " one literary composition).Under the double desulfurizing tower mode of series connection, previous stage desulfurizing tower Sulfur trioxide removal efficiency higher, the pH value of rear stage desulfurizing tower desulfurization slurry is often higher, but for sulfur trioxide Almost there is no removal effect, this explanation can be confirmed.If the sulfur dioxide in discharge flue gas can be removed by more depth, Then can effectively reduce the growing amount of acid dew in flue gas.

The method that coal-burning power plant removes sulfur trioxide in flue gas common are following three kinds：

1st, after Limestone-gypsum Wet Flue Gas Desulfurization Process tower, using wet electrical dust precipitator, there is comparison high for sulfur trioxide Removing ability, but the cost of wet electrical dust precipitator is high, and operation expense is high, and anode plants are perishable.Wet electrical dust precipitator pair Sulfur dioxide in flue gas does not almost remove effect, and after wet electrical dust precipitator, sulfur dioxide in flue gas can be by Water drop in flue gas absorbs, and after being oxidized by oxygen, forms sulfuric acid droplets.

2nd, before and after SCR denitration device, or before cleaner unit, or before desulfurizing tower, desulfurizing agent is sprayed in atomized drop mode Solution (serosity), or spray into desulfurizing agent powder, there is the high removing ability of comparison for sulfur trioxide, if spraying before air preheater Enter, can effectively reduce the generation of ammonium hydrogen sulfate, mitigate the blockage problem of air preheater.CN105233656A discloses one kind For removing the technique of sulfur trioxide in coal-fired plant flue gas, it is to adopt this method.But, this kind of method needs higher Desulfurizing agent and sulfur trioxide mol ratio, operating cost is high, and for desulfurizing tower outlet sulfur dioxide concentration not substantially Adjustment effect.The method does not have any removal effect for newly-generated sulfuric acid droplets in desulfurizing tower.

3rd, before electric precipitation arrange low-level (stack-gas) economizer, due to flue-gas temperature reduce, sulfur trioxide under the conditions of dew point temperature, Form drop, removed by dust absorbing.Existing problems are that ature of coal is required, and cigarette temperature, close to dew point, easily causes cleaner unit and sets Standby corrosion, ash bucket blocks up ash；In the case of with the use of sack cleaner, easily there is viscous bag, the problem of corrosion bag, for desulfurization Tower outlet sulfur dioxide concentration does not have obvious adjustment effect.The method is not appointed for newly-generated sulfuric acid droplets in desulfurizing tower What removal effect.

Flue gas " minimum discharge " transformation that coal-burning power plant is carried out, by carrying out increase-volume to Limestone-gypsum Wet Flue Gas Desulfurization Process tower The measures such as transformation, desulfurizing tower is significantly improved to the removal efficiency of sulfur dioxide, but these modification measures are for sulfur trioxide Removal efficiency be not obviously improved.Therefore, how deep removal discharges the oxysulfide comprising sulfur trioxide in flue gas, It is problem demanding prompt solution.

Content of the invention

It is an object of the invention to provide a kind of method of deep removal sulfureous in flue gas oxide.

Second object of the present invention is to provide a kind of device of deep removal sulfureous in flue gas oxide.

In order to realize object above, the technical solution adopted in the present invention is：

A kind of method of deep removal sulfureous in flue gas oxide, is carried out in desulfurizing tower from bottom to top successively including making flue gas First grade desulfurizing and two-grade desulfurizing；The desulfurizing agent of first grade desulfurizing is Calcium Carbonate, carries out desulphurization reaction with flue gas as a slurry, reaction Fall into the recycle slurry liquid pool of desulfurization tower bottom afterwards, circulate for first grade desulfurizing；

The desulfurizing agent of two-grade desulfurizing is sodio desulfurizing agent, Mg-base desulfurizing agent, potassio desulfurizing agent or calcium hydroxide, with solution or Slurry form is atomized in the purifying smoke after spraying into first grade desulfurizing and carries out desulphurization reaction, falls into recycle slurry liquid pool after reaction, circulation For first grade desulfurizing；

Spray into flow and/or concentration by adjust the calcium carbonate serosity that newly supplements of first grade desulfurizing, control recycle slurry liquid pool The pH value of middle loop slurry is 4.0～6.5；By adjust the desulfurizing agent solution of two-grade desulfurizing or serosity spray into flow and/or Concentration, controls the sulfoxide concentration of desulfurizing tower exiting flue gas.

General, first grade desulfurizing controls, according to conventional Limestone-gypsum Wet Flue Gas Desulfurization Process, the calcium carbonate serosity newly supplementing Flow.Can be specifically that the pH value determination according to loop slurry is feedback quantity, and set pH value to be compared first order calculation desulfurization Desulfurizing agent departure, and feedovered with the sulfur dioxide mole of the concentration of former flue gas, flow rate calculation, calculate and adjust new benefit The flow of the calcium carbonate serosity filling.The mass concentration of the calcium carbonate serosity newly supplementing is 20%～30%, and pH value is 8～10.

The method of the deep removal sulfureous in flue gas oxide of the present invention, in the base of conventional Limestone-gypsum Wet Flue Gas Desulfurization Process On plinth, using sodio desulfurizing agent, Mg-base desulfurizing agent, potassio desulfurizing agent or calcium hydroxide as two-grade desulfurizing desulfurizing agent, with solution Or slurry form is atomized in the purifying smoke after spraying into first grade desulfurizing (Limestone-gypsum Wet Flue Gas Desulfurization Process) and carries out desulphurization reaction, deep Oxysulfide in degree removing discharge flue gas, especially improves the removal efficiency of sulfur trioxide in discharge flue gas；By adjusting two The level desulfurizing agent solution of desulfurization or serosity spray into flow and/or concentration (mainly adjusting flow), control desulfurizing tower exiting flue gas The concentration of sulphur oxide.

In first grade desulfurizing, the calcium carbonate serosity newly supplementing is injected directly into flue gas and carries out desulphurization reaction, or is directly added into and follows In ring slurry pool.

Described sodio desulfurizing agent is sodium hydroxide, sodium carbonate, sodium bicarbonate；Described Mg-base desulfurizing agent is magnesium hydroxide or carbon Sour magnesium；Described potassio desulfurizing agent is potassium hydroxide, potassium carbonate or potassium bicarbonate.

The desulfurizing agent of two-grade desulfurizing sprays in flue gas with solution or slurry form atomization, and it is using compression that described atomization sprays into Air is sprayed into solution or serosity mixed aerosol, or is directly sprayed into solution or serosity pump high-pressure atomization.

General, in the desulfurizing agent of two-grade desulfurizing, sodium carbonate, sodium hydroxide, sodium bicarbonate are made solution and are used；Hydroxide Calcium, magnesium hydroxide, magnesium carbonate are made serosity and are used.Preferably, two-grade desulfurizing selects sodium carbonate liquor, sodium hydroxide solution or hydrogen Calcium oxide serosity.The mass concentration of two-grade desulfurizing desulfurizer therefor is 1%～30%.

Preferably, two-grade desulfurizing selects sodio desulfurizing agent.Because two-grade desulfurizing is the cigarette processed to first grade desulfurizing Gas carries out deep removal oxysulfide, needs the total amount of oxysulfide of removing less, the use of two-grade desulfurizing desulfurizer therefor Amount is fewer, although desulfurizing agent unit price is of a relatively high, total use cost is relatively few.Because use environment is less demanding, The quality requirements of sodio desulfurization agent material can ratio relatively low, reduce use cost with effective.As used trona (Na₂CO₃.NaHCO₃.2H₂O) as desulfurizing agent.It should be noted that the chloride ion content in desulfurizing agent to be controlled, it is to avoid big Amount chloride ion is brought in desulfurization slurry.The water of configuration solution or serosity can select demineralized water, or uses anti-penetration wastewater disposal The concentrated water discharged.

Preferably, two-grade desulfurizing uses sodium carbonate, sodium hydroxide, sodium bicarbonate, and the mass concentration of solution controls 1%～ 30%.The mass concentration of solution selects to consider desulfurizing tower water balance, removing oxysulfide efficiency, discharges the aqueous of flue gas Figureofmerit.In the case that desulfurizing agent straying quatity is certain, the mass concentration of desulfurizing agent solution lower it is meant that desulfurizing agent solution Flow is bigger, two-grade desulfurizing atomising device enter desulfurizing tower rate of water make-up bigger, the amount of droplets of atomization is more, drop total Surface area is bigger, and the chance of desulfurizing agent solution and oxysulfide reaction is more, and the efficiency of removing oxysulfide is higher, also anticipates simultaneously The water content that taste discharge flue gas can be relatively higher.In the case of conditions permit, desulfurizing agent solution selects low quality as far as possible Concentration.

Sodio desulfurizing agent dissolubility is very high, and the atomizer of two-grade desulfurizing atomising device is not susceptible to blockage problem, sodium Base desulfurizer drop itself does not have scale problems after entering demister, and therefore, its atomizing particle size can be far beyond calcio, Mg-basic desulphuration Agent is little, and such as the particle diameter of atomized drop selects at 5～50 microns, has the microspray technology of maturation can realize at present.If logical Cross the technique water yield ratio that two-grade desulfurizing atomising device fills into larger, the mass concentration ratio of desulfurizing agent solution relatively low it is also possible to select The particle diameter of atomized drop is some larger.If only considering to control the concentration of emission of discharge sulfur dioxide in flue gas, do not consider three oxygen Change the concentration of emission of sulfur, then the atomizing particle size of sodio desulfurizing agent solution can be relatively large, so can better control over discharge The water content of flue gas.

Two-grade desulfurizing selects sodio desulfurizing agent.Sodio desulfurizing agent drop itself does not have scale problems after entering demister, and two Level desulfurization atomising device and the demister spacing above it can be less, within such as may remain in 1 meter.For existing desulfurizing tower Transformation project gets final product effective mounting arrangements two-grade desulfurizing atomising device it may not be necessary to increase desulfurizing tower.Sodio desulfurizing agent and sulfur oxygen The reactant of compound enters in recycle slurry liquid pool, can increase the sodio composition of desulfurization slurry, in desulfurization wastewater, sodium ion becomes decilitre Height, but impact is not produced for sulfur removal technology.

The present invention discharges the acidic materials such as the oxysulfide in flue gas by deep removal, can effectively reduce to desulfurizing tower Rear portion flue, the sour corrosion of chimney runner.The sodio mist droplet part that effectively can not be removed by demister, with discharge flue gas After desulfurizing tower is discharged, need the runner of the flue and chimney passing through also long, longer runner can be oxysulfide, take off Sulfur agent drop carries out sufficient neutralization reaction provides effective space, effective response time.In runner, sodio mist droplet Can be sufficiently mixed with the acidic materials in flue gas, proceed sufficient neutralization reaction, thus effectively reducing the acid in runner Property corrosion.

If only considering to control the concentration of emission of discharge sulfur dioxide in flue gas, do not consider the concentration of emission of sulfur trioxide, Two-grade desulfurizing desulfurizer therefor can also adopt calcium hydroxide, makes serosity, and the mass concentration of serosity controls 5%～30%. Calcium-based desulfurizing agent selects the larger atomizing particle size of ratio, between such as particle diameter selects 500～1500 microns.Calcium hydroxide is de- as two grades The desulfurizing agent of sulfur, on the one hand its price is relatively inexpensive, and alkalescence is strong compared with Calcium Carbonate, and raw material is readily available, such as calcium oxide and water reaction Can get, or calcium hydroxide cream (powder) adds water configuration；On the other hand, its reactant is calcium sulfate or calcium sulfite, and stone Lime stone-gypsum wet sulfur removal technology product is the same.

The method of the deep removal sulfureous in flue gas oxide of the present invention is on the basis of Limestone-gypsum Wet Flue Gas Desulfurization Process, right The first grade desulfurizing processed sulfoxide concentration relatively low flue gas of ratio, particularly wherein comprises the sulfur trioxide more than comparison The flue gas of composition, is used the desulfurizing agent as two-grade desulfurizing for the alkaline matter of high ph-values, with solution or slurry form, by atomization Injection, the further deep desulfuration to flue gas；The method has remarkable result to the removing of oxysulfide, especially to sulfur trioxide There is obvious removal effect, be capable of preferably removing the purpose of oxysulfide；Discharged in flue gas by deep removal The acidic materials such as oxysulfide, reduce the sour corrosion effect to desulfurizing tower rear portion flue stack.By adjusting two-grade desulfurizing Desulfurizing agent solution or serosity spray into flow and/or concentration, control discharge sulfur dioxide in flue gas, sulfur trioxide or sulfur oxidation The concentration of thing, can quickly adjust the concentration of discharge sulfureous in flue gas oxide, meet emission request；The method is directly to discharge flue gas Sulphur oxide target concentration value is control targe, has the advantages that fast response time, degree of regulation height, regulation quality are good；And The original control system of desulfurizing tower is used for keeping the running environment of desulfurizing tower, controls desulfuration efficiency.

The desulfurizing agent of two-grade desulfurizing is sprayed into solution or slurry form atomization, generally selects adverse current and sprays into mode.Adverse current mist Change and spray into the effect that mode can play certain water curtain dedusting, certain removing is risen for the nominal particle size dust after desulfurization Effect, also has certain removing to act on for hydrogen chloride, fluohydric acid gas.

The desulfurizing agent of two-grade desulfurizing uses strong alkaline substance, especially with sodium hydroxide as desulfurizing agent in the case of, Also can there is certain removal effect for nitrogen oxides.Reaction equation is：

2NaOH+2NO₂=NaNO₃+NaNO₂+H₂O；

2NaOH+NO₂+ NO=2NaNO₂+H₂O.

In the case of the acidic materials such as deep removal oxysulfide, in flue after desulfurizing tower, chimney link, flue gas In acid quality be remarkably decreased, under Wet chimney environment, the corrosive environment for flue, chimney can effectively be changed Kind, the service life of flue, chimney can be extended.

In the described method of deep removal sulfureous in flue gas oxide, by adjusting desulfurizing agent solution or the slurry of two-grade desulfurizing Liquid spray into flow and/or concentration, control the method for the sulfoxide concentration of desulfurizing tower exiting flue gas to comprise the following steps：

1) the target gas levels actual measured value according to desulfurizing tower exiting flue gas and the difference of target control value, are multiplied by cigarette Air flow value, calculates the departure of desulfurizing tower exit object gas；

2) departure of desulfurizing tower exit object gas is multiplied by the alkali sulfur ratio of setting, calculates and need the two of adjustment The amount of the desulfurizing agent of level desulfurization；Described alkali sulfur ratio is calcium sulfur ratio, sodium sulfur ratio, magnesium sulfur ratio or potassium sulfur ratio；

3) the adjustment desulfurizing agent solution of two-grade desulfurizing or serosity spray into flow and/or concentration, the desulfurizing agent being sparged into Adjustment amount is not less than step 2) gained need adjustment desulfurizing agent amount.

Further, spray into flow and/or concentration by adjust the desulfurizing agent solution of two-grade desulfurizing or serosity, control de- The method of the sulfoxide concentration of sulfur tower exiting flue gas specifically includes following steps：

1) concentration measurement of the object gas according to discharge flue gas, through the interval object gas of history in control time Mean concentration is modified, and subtracts each other with the concentration target controlling value of the object gas setting and obtains deviation concentration value, is multiplied by control The flue gas flow measured value of period processed, calculates the deviation quality that this control time discharges the object gas in flue gas；Divided by target The molecular weight of gas, obtains the deviation mole of object gas；

2) the deviation mole of object gas is multiplied by alkali sulfur ratio (calcium sulfur ratio, sodium sulfur ratio, magnesium sulfur ratio or the potassium sulfur of setting Than), obtain the deviation mole of the desulfurizing agent of two-grade desulfurizing of needs adjustment；It is multiplied by the molecular weight of desulfurizing agent, be calculated pure The deviation quality of net desulfurizing agent；Divided by the purity of desulfurizing agent, it is calculated the deviation quality of practical sulphur removal agent；Molten divided by desulfurizing agent Liquid or concentration of slurry value, are calculated the deviation quality of desulfurizing agent solution or serosity；Divided by desulfurizing agent solution or serum density value, It is calculated the desulfurizing agent solution of two-grade desulfurizing or the deviation flow of serosity；

3) the deviation flow of the desulfurizing agent solution according to calculated two-grade desulfurizing or serosity, adjusts the de- of two-grade desulfurizing Sulfur agent solution or serosity spray into flow, the adjustment amount of the desulfurizing agent being sparged into is not less than step 2) gained needs the desulfurization of adjustment The departure of agent.

Described object gas are sulfur dioxide and/or sulfur trioxide.When object gas are for sulfur dioxide, according to above-mentioned meter Calculation method calculates the deviation flow of the required desulfurizing agent solution of two-grade desulfurizing or serosity, and the removal efficiency according to sulfur trioxide Carry out appropriateness to revise.When object gas are for sulfur trioxide, calculate the de- of required two-grade desulfurizing according to above-mentioned computational methods The deviation flow of sulfur agent solution or serosity, and appropriateness correction is carried out according to the removal efficiency of sulfur dioxide.When object gas are dioxy The desulfurizing agent solution of the two-grade desulfurizing required for sulfur dioxide when changing sulfur and sulfur trioxide, is calculated respectively according to above-mentioned computational methods Or the deviation flow of the desulfurizing agent solution of two-grade desulfurizing required for the deviation flow of serosity, sulfur trioxide or serosity, take the two Sum, and after appropriateness is revised, the desulfurizing agent solution as two-grade desulfurizing or the deviation flow of serosity.

Described appropriateness revises the deviation flow referring to the desulfurizing agent solution of calculated for gained two-grade desulfurizing or serosity It is multiplied by correction factor.Due to desulfurizing agent simultaneously can scrubbing CO_2 and sulfur trioxide drop, the desulfurization of above-mentioned calculating gained The deviation flow of agent solution or serosity relatively can be less than normal, therefore need to be multiplied by certain correction factor.Correction factor according to history value and Empirical value determines.Preferably, described correction factor is 1.0～2.0.

In above-mentioned computational methods, the concentration measurement of the object gas of discharge flue gas can adopt measured concentration value；Examining In the case that core target is the mean concentration of control time discharge, for improving regulation quality, can going through with this control time The arithmetic mean of instantaneous value of the interval actual discharge concentration of history is modified by certain algorithm to measured concentration value, e.g., dense to survey The arithmetic mean of instantaneous value weighted average of the actual discharge concentration in angle value and this control time history interval, its result is as revised Concentration measurement.

To adjust the method that desulphurization system discharges flue gas concentration, there is big time delay in existing conventional control loop slurry pH value Characteristic, comparison of regulating the speed be slow the problems such as the degree of association is relatively low and between object gas concentration of emission.Wet for limestone-gypsum For method sulfur removal technology, the factor of the sulfoxide concentration of impact desulfurizing tower exiting flue gas is a lot, and the calcium sulfur ratio of device, desulfurization The liquid-gas ratio (method of operation of circulation slurry pump) of serosity, absorption tower slurry pH value, serum recycle amount etc. are relevant.When using coal Complexity, mixes in the case that burning has sulphur coal, the sulfoxide concentration of neat stress can have a greater change.It is high when burning persistently occurs In the case of sulfur coal, it is easy to sulfur dioxide row occurs in the case that quick liter generation load, flue gas flow increase ratio are very fast Put concentration over-standard phenomenon, and traditional regulating measure is limited.In the case of the concentration of emission needing to control sulfur trioxide, this kind of Traditional control method is almost not much regulating power.

What the present invention passed through to adjust the desulfurizing agent solution of two-grade desulfurizing or serosity sprays into flow and/or concentration, controls desulfurization The sulfoxide concentration of tower exiting flue gas, the control effect of desulphurization system can be significantly improved.Two-grade desulfurizing atomising device It is mainly used in controlling the sulfoxide concentration of discharge flue gas it is ensured that discharge is qualified；And the Gypsum Wet of first grade desulfurizing takes off The reaction environment of sulfur technique major control desulfurizing tower, keeps desulfurizing tower to have higher desulfuration efficiency it is not necessary to quick regulation discharges cigarette The concentration of emission of gas.So, both can ensure that concentration of emission was qualified it is also ensured that desulfurizing tower keeps high desulfuration efficiency, right Change in former flue gas sulfoxide concentration, exhaust gas volumn has good adaptability.And existing sulfur removal technology control method one side Face will ensure that desulfurization discharge is qualified, will adjust the reaction environment of desulfurizing tower interior circulation slurry pool simultaneously, keep desulfuration efficiency, exist The problem being difficult between the two take into account.And the method for the present invention can preferably take into account the two.

The concentration of discharge sulfureous in flue gas oxide in the method, can be quickly adjusted by the two-grade desulfurizing independently arranged Value.The present invention can combine with conventional desulphurization system runing adjustment means, improves the economy run, the such as spray of loop slurry Inbound traffics control.Spray into it may not be necessary to increase loop slurry in the case that discharge sulfoxide concentration is close to emission request Amount, desulfurizing agent solution or slurry flow in a small amount of increase two-grade desulfurizing atomising device, thus effectively save circulation slurry pump The electric energy consuming.When the rising of former flue gas sulfoxide concentration is more, or flue gas flow increase is relatively more, needs to roll up two grades In the case of desulfurizing agent solution or slurry flow in desulfurization atomising device, standby circulation slurry pump can be started, increase recycle slurry The straying quatity of liquid, reduces desulfurizing agent solution or the slurry flow of two-grade desulfurizing atomising device.So, ensureing qualified discharge sulfur oxygen On the basis of compound, optimizing in terms of energy-conservation and economical operation, the motility of runing adjustment is higher.More useful it is, due to Meet being obviously improved of ability of emission request, for the significantly change of former flue gas sulfoxide concentration, flue gas flow quick Change aspect can have quick regulation respond, and the sulfur content alternative scope for coal becomes big, mixes for coal blending The aspects such as burning, reduction fuel cost can provide effective support.

In the method for deep removal sulfureous in flue gas oxide of the present invention, the calcium carbonate serosity Flow-rate adjustment control of first grade desulfurizing Aspect processed, still according to the method controlling loop slurry pH value, adjusts calcium carbonate serosity flow, keeps the reaction environment of desulfurizing tower, Keep good desulfuration efficiency.For accelerating the reaction speed of first grade desulfurizing (Limestone-gypsum Wet Flue Gas Desulfurization Process technique), can be by The desulfurizing agent solution of two-grade desulfurizing or serosity regulated quantity are incorporated into the control and regulation link of calcium carbonate serosity flow.

A kind of device of deep removal sulfureous in flue gas oxide, including desulfurizing tower, is provided with flue gas below described desulfurizing tower and enters Mouth, top are provided with exhanst gas outlet, are sequentially provided with first grade desulfurizing from bottom to top in desulfurizing tower between gas approach and exhanst gas outlet Spray equipment and two-grade desulfurizing atomising device, described first grade desulfurizing spray equipment includes the loop slurry setting gradually from bottom to top Spraying layer and one-level highest spraying layer, described one-level highest spraying layer is used for spraying into the Calcium Carbonate slurry newly supplementing into desulfurizing tower Liquid；Described two-grade desulfurizing atomising device is used for spraying into sodio desulfurizing agent, Mg-base desulfurizing agent, potassio desulfurizing agent to desulfurizing tower is atomization Or the solution of calcium hydroxide or serosity；Desulfurization tower bottom is provided with recycle slurry liquid pool, for access first grade desulfurizing spray equipment and two The material that level desulfurization atomising device sprays into, described loop slurry spraying layer is connected with recycle slurry liquid pool, for Sprayer Circulation serosity.

The device of described deep removal sulfureous in flue gas oxide also includes one-level liquid dispensing device, described one-level liquid dispensing device bag Include first grade desulfurizing and join liquid pool, for preparing calcium carbonate serosity.Described first grade desulfurizing is joined liquid pool and is connected with one-level highest spraying layer, uses In being injected directly into the calcium carbonate serosity newly supplementing in desulfurizing tower, or connect with recycle slurry liquid pool, for carbon that will be newly supplementary Sour calcium serosity directly fills into recycle slurry liquid pool.

The device of described deep removal sulfureous in flue gas oxide also includes graduation two liquid device, described graduation two liquid device bag Include two-grade desulfurizing and join liquid pool, for preparing sodio desulfurizing agent, the solution of Mg-base desulfurizing agent, potassio desulfurizing agent or calcium hydroxide or slurry Liquid；Described two-grade desulfurizing is joined liquid pool and is connected with two-grade desulfurizing atomising device, for will prepare sodio desulfurizing agent, Mg-basic desulphuration In the solution of agent, potassio desulfurizing agent or calcium hydroxide or serosity direct atomisation desulfurizing tower.

Described graduation two liquid device also includes compressed air reservoir.

It is provided with demister between first grade desulfurizing spray equipment and two-grade desulfurizing atomising device in desulfurizing tower.

General, it is provided with demister in the lower section of exhanst gas outlet in desulfurizing tower；Two-grade desulfurizing spray equipment is arranged on desulfurization In tower between first grade desulfurizing spray equipment and demister.It is arranged in this position and is based on both sides reason, one is to take off through one-level The removing effect of the spraying layer of sulfur spray equipment, the sulfoxide concentration of this position flue gas is very low, first grade desulfurizing de- Sulfur agent serosity or loop slurry are remarkably decreased to the removing ability of its spray-absorption again, and select the two-grade desulfurizing with high ph-values Desulfurizing agent solution or pulp level are atomized after spraying into, desulfurization that two-grade desulfurizing use very high to the removal efficiency of oxysulfide Dosage is few；Two are the desulfurizing agent solution of the two-grade desulfurizing that high atomisation sprays into or drop that serosity is formed must some meeting Carried away by flue gas, when demister, most of desulfurizing agent solution or slurry droplet can be intercepted by demister effectively, keep away Exempt from the flue that a large amount of drops enter after demister, effective control discharges the water content of flue gas.

The atomized spray coverage rate of two-grade desulfurizing atomising device can be arranged according to the practical situation of desulfurizing tower and flue.One As, the coverage rate of atomized spray is between 100%～200%；Described atomized spray is that adverse current sprays into.Preferably, two grades take off Sulfur atomising device is maintained at 1～2m, with top with the distance of the first grade desulfurizing spray equipment (one-level highest spraying layer) of bottom The distance of demister is maintained at 1～3m.

It is provided with demister between two-grade desulfurizing atomising device and exhanst gas outlet in desulfurizing tower.Many when being disposed with desulfurizing tower During level demister, two-grade desulfurizing atomising device may be arranged between multi-stage demister, is preferably placed in the first order from bottom to top and removes After day with fog.Can desulfurizing adsorbent two-grade desulfurizing atomising device according to used by two-grade desulfurizing concrete position.

When two-grade desulfurizing selects sodio desulfurizing agent, two-grade desulfurizing atomising device may be arranged between multi-stage demister, preferably It is arranged in from bottom to top after first order demister.Along flow of flue gas direction, every grade of demister is equipped with matching used demisting Device flusher.

Carry substantial amounts of acidity drop in the flue gas entering first order demister, arrange two-grade desulfurizing before demister Atomising device, the acid in a large number drop carrying in flue gas must occur with the desulfurizing agent drop of two-grade desulfurizing atomising device atomization Neutralization reaction, reduces the ability that desulfurizing agent removes the oxysulfide of low concentration in flue gas.After first order demister, flue gas In big particle diameter acidity drop major part be removed, after two-grade desulfurizing atomising device is arranged in first order demister, Neng Gouyou Effect improves to oxysulfide removal efficiency.Demister after two-grade desulfurizing atomising device can effectively remove two-grade desulfurizing atomization dress Put the desulfurizing agent drop spraying into, control the flue gas water content in the rear pass of demister.Even if desulfurizing agent drop can not be by rear portion Demister remove completely, it still can neutralize acidic materials under the sour environment of rear portion flue, plays removing sulfur oxidation The effect of thing, will not produce adverse consequencess.When demister except fog effect is very good, or in the case of arrangement three-level demister, After being more suitable for for two-grade desulfurizing atomising device being arranged in first order demister.

The exhanst gas outlet of desulfurizing tower is connected with flue, and described flue is provided with flue demister or wet electrical dust precipitator.Wet Formula electric cleaner plays the effect to two-grade desulfurizing atomising device demisting, can effectively remove the sulphuric acid liquid of sulfur trioxide formation Drip.Two-grade desulfurizing atomising device can with wet electrical dust precipitator work in coordination with deep removal oxysulfide, reduce wet electrical dust precipitator it Sulfur oxides level afterwards, and then mitigate the sour corrosion to flue and chimney.

Described flue demister or wet electrical dust precipitator are connected with collecting tank by pipeline, for collecting by flue demister Or the liquid that wet electrical dust precipitator intercepts.Described collecting tank is joined liquid pool by defecator and two-grade desulfurizing and is connected.Collecting tank The liquid collecting collected makes clear liquid through defecator, and clear liquid returns to two-grade desulfurizing and joins liquid pool, recycles, and improves making of desulfurizing agent With efficiency, save the supplementary water of desulfurizing agent solution；The turbid liquid that defecator produces enters the recycle slurry liquid pool in desulfurizing tower.

In the case of being disposed with demister and horizontal flue demister in desulfurizing tower, two-grade desulfurizing atomising device is preferably It is arranged in above demister in desulfurizing tower.After the removing of demister in desulfurizing tower, the acid drop amount in flue gas has shown Write and decline.On the one hand, in desulfurizing tower, the removing of demister acts on, and the acid droplet content in flue gas declines substantially, permissible Save the desulfurizing agent usage amount of two-grade desulfurizing；On the other hand, two-grade desulfurizing atomising device is arranged in above demister in desulfurizing tower, Before horizontal flue demister, arrangement space is relatively abundant, two-grade desulfurizing atomising device and horizontal flue demister it Between distance can keep farther out, desulfurizing agent drop and small acid drop, sulfur dioxide gas etc. can more fully mix, There are more fully reaction compartment and response time, be conducive to deep removal oxysulfide.Meanwhile, horizontal flue demister demisting, Rinse the collection solution being formed and converge to collecting tank, the clear liquid after being separated by filtration fills into two-grade desulfurizing and joins liquid pool, recycle, Improve the service efficiency of desulfurizing agent, save the supplementary water of desulfurizing agent solution；Turbid liquid enters desulfurizing tower interior circulation slurry pool.

The device of the deep removal sulfureous in flue gas oxide of the present invention, during use, former flue gas enters from gas approach, de- Flow from bottom to top in sulfur tower, the material spraying into first grade desulfurizing spray equipment successively carries out first grade desulfurizing and two-grade desulfurizing mist The material that gasifying device sprays into carries out two-grade desulfurizing, and neat stress is discharged from exhanst gas outlet；The calcium carbonate serosity of first grade desulfurizing passes through one Level highest spraying layer adverse current sprays into and carries out desulphurization reaction in flue gas, and the recycle slurry liquid pool formation falling into desulfurization tower bottom after reaction follows Ring serosity；Loop slurry sprays in flue gas through loop slurry spraying layer adverse current and carries out desulphurization reaction, falls into loop slurry after reaction Pond is circulated for first grade desulfurizing；The desulfurizing agent solution of two-grade desulfurizing or serosity pass through two-grade desulfurizing atomising device atomization adverse current and spray into Carry out deep desulfuration in purifying smoke after first grade desulfurizing, fall into recycle slurry liquid pool after reaction, circulate for first grade desulfurizing.This dress Put and two-grade desulfurizing atomising device is set in the top of first grade desulfurizing spray equipment (Limestone-gypsum Wet Flue Gas Desulfurization Process), using two grades The desulfurizing agent of desulfurization, with solution or slurry form, by atomized spray, the sulfoxide concentration processed to first grade desulfurizing is Through the relatively low flue gas of ratio, particularly wherein comprise the further deep desulfuration of flue gas of the sulfur trioxide composition more than comparison, to sulfur oxygen The removing of compound has remarkable result, especially has obvious removal effect to sulfur trioxide, is capable of preferably removing The purpose of oxysulfide；The acidic materials such as the oxysulfide in flue gas are discharged by deep removal, reduces to desulfurizing tower rear portion cigarette The sour corrosion effect of road chimney.

Brief description

Fig. 1 is the structural representation of the device of deep removal sulfureous in flue gas oxide of embodiment 1；

Fig. 2 is the schematic flow sheet of the sulfoxide concentration controlling desulfurizing tower exiting flue gas in embodiment 1；

Fig. 3 is the structural representation of the device of deep removal sulfureous in flue gas oxide of embodiment 2；

Fig. 4 is the structural representation of the device of deep removal sulfureous in flue gas oxide of embodiment 3；

Fig. 5 is the structural representation of the device of deep removal sulfureous in flue gas oxide of embodiment 4.

Specific embodiment

With reference to specific embodiment, the present invention is further illustrated.

Embodiment 1

The device of the deep removal sulfureous in flue gas oxide of the present embodiment, as shown in figure 1, inclusion desulfurizing tower 1 and one-level are joined Liquid device, graduation two liquid device, described desulfurizing tower 1 sprays void tower for single column single cycle；Described one-level liquid dispensing device includes one-level Liquid pool 10 is joined in desulfurization, and described graduation two liquid device includes two-grade desulfurizing and joins liquid pool 13 and compressed air reservoir 14；

It is provided with gas approach 2, top is provided with exhanst gas outlet 3, desulfurization tower bottom is provided with loop slurry below described desulfurizing tower 1 Pond 4；Be sequentially provided with from bottom to top between gas approach 2 and exhanst gas outlet 3 in desulfurizing tower 1 first grade desulfurizing spray equipment, two grades Desulfurization atomising device 7 and demister 8, described demister 8 is two-stage demister, and along flow of flue gas direction, every grade of demister is all provided with There is matching used mist eliminator flushing device 9；

Described first grade desulfurizing spray equipment includes the loop slurry spraying layer 5 setting gradually from bottom to top and the spray of one-level highest Drench layer 6, described one-level highest spraying layer 6 includes upper and lower two-stage list spraying layer, described loop slurry spraying layer 5 passes through circulating line It is connected with recycle slurry liquid pool 4, by the circulation slurry pump 12 that is arranged on circulating line by the recycle slurry in recycle slurry liquid pool 4 Liquid pump enters loop slurry spraying layer 5, and loop slurry is sprayed in flue gas；The two-stage list spraying layer of one-level highest spraying layer 6 also divides It is not connected with recycle slurry liquid pool 4, sprayed into loop slurry in flue gas by circulation slurry pump；The two of one-level highest spraying layer 6 The single spraying layer of level is also joined liquid pool 10 by one-level liquid distribution pipe road and first grade desulfurizing respectively and is connected, and first grade desulfurizing is joined in liquid pool 10 Calcium carbonate serosity enters one-level highest spraying layer 6 by the one-level solution feed pump 11 that is arranged on one-level liquid distribution pipe road, for de- The calcium carbonate serosity newly supplementing is sprayed in sulfur tower 1；One-level liquid distribution pipe road is provided with switch valve, makes one-level highest spraying layer 6 Two-stage list spraying layer is changeable to access the calcium carbonate serosity newly supplementing；

Described two-grade desulfurizing atomising device 7 joins liquid pool 13, compressed air respectively by graduation two liquid pipe road with two-grade desulfurizing Air accumulator 14 is connected, and joins with two-grade desulfurizing and is additionally provided with two grades of solution feed pumps 15 on the graduation two liquid pipe road that liquid pool 13 is connected；Two grades Desulfurization atomising device 7 includes layer of spraying, and described spraying layer adopts pneumatic type two-fluid spray nozzle, independent control air mass flow and two grades The desulfurizing agent solution flow of desulfurization, adjusts the gas entering pneumatic type two-fluid spray nozzle and fluid flow, and two-fluid spray nozzle produces Small atomized drop spray in flue gas, react with oxysulfide；Wherein, one-level joins liquid pump 11, graduation two liquid pump 15 all adopts Frequency conversion form, the convenient flow controlling serosity or solution；

The recycle slurry liquid pool 4 access first grade desulfurizing spray equipment of desulfurizing tower 1 bottom and two-grade desulfurizing atomising device 7 spray into Material, forms loop slurry, recycles for first grade desulfurizing spray equipment.

The method of the deep removal sulfureous in flue gas oxide of the present embodiment, using above-mentioned deep removal sulfureous in flue gas oxidation The device of thing；The method includes：Former flue gas enters from gas approach 2, flows from bottom to top in desulfurizing tower 1, successively with one-level The material that desulfurization spray equipment sprays into carries out the material that first grade desulfurizing sprayed into two-grade desulfurizing atomising device 7 and carries out two-grade desulfurizing, After demister 8 demisting, neat stress is discharged from exhanst gas outlet 3；

The desulfurizing agent of first grade desulfurizing is Calcium Carbonate, joins in liquid pool 10 in first grade desulfurizing and is configured to calcium carbonate serosity, through one-level Solution feed pump 11 pumps into one-level highest spraying layer 6, countercurrently sprays in flue gas and carries out desulphurization reaction, falls into desulfurizing tower 1 bottom after reaction Recycle slurry liquid pool formed loop slurry；Loop slurry pumps into loop slurry spraying layer 5 through circulation slurry pump 12, countercurrently sprays into cigarette Carry out desulphurization reaction in gas, fall into recycle slurry liquid pool after reaction, circulate for first grade desulfurizing；

The desulfurizing agent of two-grade desulfurizing is sodium carbonate, joins in liquid pool 13 in two-grade desulfurizing and is configured to sodium carbonate liquor, through two grades Solution feed pump 15 pumps into two-grade desulfurizing atomising device 7, mixes with the compressed air from compressed air reservoir 14, and atomization adverse current is sprayed Enter in the purifying smoke after first grade desulfurizing and carry out deep desulfuration, fall into recycle slurry liquid pool after reaction, circulate for first grade desulfurizing；

The calcium carbonate serosity that first grade desulfurizing is newly supplemented is filled into by one-level highest spraying layer 6；New by adjusting first grade desulfurizing The calcium carbonate serosity supplementing spray into flow and/or concentration, the pH value controlling loop slurry in recycle slurry liquid pool is 4.0～6.5； By adjusting the oxysulfide spraying into flow and/or concentration, controlling desulfurizing tower exiting flue gas of the sodium carbonate liquor of two-grade desulfurizing Concentration.

In the present embodiment, two-grade desulfurizing selects sodium carbonate as desulfurizing agent, and sodium carbonate and its reaction product are soluble in water, Do not result in demister scale problems；, between 5～50 microns, the mass concentration of sodium carbonate liquor is 1% for the particle diameter of atomized drop Select between～30%.Sodium carbonate as the desulfurizing agent of two-grade desulfurizing, with compressed gas atomizing type, through two-grade desulfurizing atomising device Spray in desulfurizing tower, there is the ability of very strong quick regulation neat stress sulfoxide concentration, do not easily cause demister fouling.

Before two-grade desulfurizing atomising device is arranged in demister, the desulfurizing agent droplet that spraying layer is formed acts in demister Under, can well be removed by demister, reduce the water content of discharge flue gas.Desulfurizing tower exiting flue gas fail to be removed by demister Desulfurizing agent droplet can enter in the acid flue environment at rear portion, also have an opportunity and sulfur trioxide drop, sulfur dioxide gas are carried out Neutralization reaction.

In other embodiments of the invention, inferior sodium carbonate may also be employed as the desulfurizing agent of two-grade desulfurizing, such as Trona (Na using relative low price₂CO₃.NaHCO₃.2H₂O), simply need to control chloride ion content therein.

In the method for deep removal sulfureous in flue gas oxide of embodiment 1, by adjusting the sodium carbonate liquor of two-grade desulfurizing Method (the schematic flow sheet such as Fig. 2 institute spraying into flow and/or concentration, controlling the sulfur trioxide concentration of desulfurizing tower exiting flue gas Show) it is specially：

1) calculate concentration of emission deviation：

(current national standard is for sulfur trioxide concentration value in discharge flue gas according to outside examination：With chimney porch Sulfur dioxide concentration hourly average measured value is judgment basis, and sulfur trioxide considers according to same position), set exiting flue gas three The target control value of sulfur oxide concentration；Sulfur trioxide concentration actual measured value (or correction value) according to discharge flue gas and target control The difference of value processed, calculates the deviation concentration of sulfur trioxide in discharge flue gas；

2) in the unit of account time sulfur trioxide deviation mole：

The hour cigarette of current time using hour as the time span of control time, is obtained according to discharge flue gas measurement Tolerance, is multiplied by step 1) gained sulfur trioxide concentration of emission deviation, obtain the deviation quality of sulfur trioxide；Deviation quality divided by The molecular weight 80 of sulfur trioxide, obtains its deviation mole；

3) in the unit of account time sodium carbonate liquor deviation flow：

By the deviation mole of sulfur trioxide be multiplied by given sodium sulfur ratio (because sodium carbonate and sulphuric acid, sulfurous acid anti- Ratio is answered to be all 1:1, sodium sulfur ratio generally selects 1.02-1.1, and sodium sulfur is than selection 1.05 herein), obtain the deviation mole of sodium carbonate Amount；Sodium carbonate deviation mole is multiplied by the molecular weight 106 of sodium carbonate, obtains the deviation quality of pure sodium carbonate；Sodium carbonate Deviation quality, divided by the purity of sodium carbonate, obtains the deviation quality of sodium carbonate in kind；The deviation quality of sodium carbonate in kind is divided by carbon The mass concentration of acid sodium solution, obtains the deviation quality of sodium carbonate liquor；The deviation quality of sodium carbonate liquor is molten divided by sodium carbonate The density of liquid, obtains the deviation flow of sodium carbonate liquor；

4) adjust sodium carbonate liquor flow：

According to removing sulfur trioxide needed for sodium carbonate liquor deviation flow, plus sodium carbonate needed for scrubbing CO_2 molten The deviation flow of liquid, revises after (correction factor is 1.8) through appropriateness according to the removal efficiency situation of sulfur dioxide, sulfur trioxide, leads to Cross the control devices such as PID regulation, calculate two grades of feed flow revolution speeds of adjustment, realize adjustment sodium carbonate liquor flow；

5) accelerate adjustment calcium carbonate serosity flow：

For improving the adjustment response speed of desulfurization slurry cyclic part, by the deviation flow of the sodium carbonate liquor of two-grade desulfurizing Value is simultaneously communicating to one-level feed flow apparatus for controlling pump, accelerates to adjust its flow.

Another feedback quantity (base that the departure of the sodium carbonate liquor based on two-grade desulfurizing adjusts as calcium carbonate serosity flow This feedback quantity be desulfurization slurry pH measured value), when its value be on the occasion of when, show first grade desulfurizing need additionally increase the carbon filling into Sour calcium serosity amount, when its value is negative value, shows that first grade desulfurizing needs extra minimizing to fill into calcium carbonate serosity amount, thus accelerating one The governing response speed of level desulfurization.

Certain 1000MW coal unit adopts the device and method of the deep removal sulfureous in flue gas oxide of embodiment 1, to this The adjustment of 1000MW coal unit runs and illustrates.Outside examines the sulfur trioxide hourly average for the collection of chimney porch dense Angle value.The mass concentration of sodium carbonate is 5%, and sodium carbonate liquor density takes 1.04kg/L；Sodium carbonate purity takes 95%；Sodium sulfur ratio takes 1.05.By adjusting three oxygen spraying into flow and/or concentration, controlling desulfurizing tower exiting flue gas of the sodium carbonate liquor of two-grade desulfurizing The method changing sulphur concentration specifically includes following steps：

A) set the objectives of examination of sulfur trioxide as 20mg/Nm³, set the target control of exiting flue gas sulfur trioxide concentration It is worth for 15mg/Nm³；

When the 31st minute this little period, generation load was 800MW to this unit, and at chimney, flue gas flow is 3250kNm³/ H, the sulfur trioxide average emission concentration of first 31 minutes of this period is 15.2mg/Nm³(the interval arithmetic average of control time history Value)；When the 32nd minute this little period, generation load was 801MW to this unit, and at chimney, flue gas flow is 3300kNm³/ h, three Sulfur oxide concentration is 19.0mg/Nm³, the flow of two grades of solution feed pumps (sodium carbonate liquor) is 3.5m³/h；

Calculate the sulfur trioxide concentration of emission measured value of weighted average correction, 15.2*70%+19*30%=16.3mg/ Nm³；(weight coefficient of weighted average correction herein is according to the interval arithmetic mean of instantaneous value of control time history and sulfur trioxide row The weight putting concentration measurement empirically sets.When more emphasizing desulfurization stationarity, the interval arithmetic of control time history is put down The weight of average increases；When more emphasizing the governing response speed of desulfurization, the weight of sulfur trioxide concentration of emission measured value increases. Both take 100% at weight sum.)

The sulfur trioxide average emission concentration of first 32 minutes is (15.2*31+19.0)/32=15.3mg/Nm³；

Measured value and target setting value 15mg/Nm³Compare, the sulfur trioxide concentration deviation of discharge flue gas is 16.3-15 =1.3mg/Nm³；

B) in flue gas, the deviation quality of sulfur trioxide is 3300000Nm³*1.3mg/Nm³=4290g；

The deviation mole of sulfur trioxide is 4290g/80=53.6mol；

C) sodium sulfur ratio takes 1.05, then the deviation mole of sodium carbonate is 53.6*1.05=56.3mol；

Sodium carbonate molecule amount is 106, then pure sodium carbonate deviation quality is 56.3*106=5968g；

The purity of sodium carbonate takes 95%, then actual sodium carbonate deviation quality is 5968/95%=6282g；

Sodium carbonate liquor mass concentration is 5%, then the deviation quality of sodium carbonate liquor is 6282/5%=125638g= 125.6kg；

Sodium carbonate liquor density is 1.04kg/L, then the deviation volume of sodium carbonate liquor is 125.6/1.04=120.8L；

Adjustment needs to increase the flow of 120.8L/h.

D) due to the concentration of emission of sulfur dioxide to be adjusted simultaneously, need exist for plus adjustment sulfur dioxide emissioning concentration institute The deviation volume of the sodium carbonate liquor needing, and the removal efficiency according to the sulfur dioxide under corresponding reaction condition, sulfur trioxide Value, on the premise of ensureing that target discharge thing is qualified, revises after (correction factor is 1.8) through appropriateness, then sodium carbonate liquor is inclined Difference volume is 120.8*1.8=217.4L, and adjustment needs to increase the flow of 217.4L/h..In two grades of solution feed pumps, (sodium carbonate is molten Liquid) output 3.5m³On the basis of/h, new flow target value is 3.5+217.4/1000=3.72m³/h.

Two grades of feed flow pump control systems are calculated by PID, calculate the rotating speed of two grades of solution feed pumps of adjustment and execute.

For improving the reaction speed of two-grade desulfurizing atomising device, the former SO 2 from fume of desulfurizing tower can be introduced simultaneously Concentration measurement and the product of flue gas flow value, as the feedforward link of the desulfurizing agent solution flow PID control of two-grade desulfurizing.

For improving the adjustment response speed of first grade desulfurizing cyclic part, the desulfurizing agent solution of two-grade desulfurizing or serosity is inclined Difference flow value is simultaneously communicating to one-level solution feed pump (calcium carbonate serosity) control device, accelerates to adjust its flow.

The estimation spraying into sodium carbonate liquor for exiting flue gas oxysulfide control result is as follows：

With two-grade desulfurizing atomising device 3.5m³/ h straying quatity is estimated, the quality of the oxide spinel sodium spraying in 1 hour is 3.5*1.04*5%=0.1785T=178.5kg；

Pure sodium carbonate quality is 178.5*95%=169.6kg；Its mole is 169.6*1000/106= 1600mol；Here the sodium carbonate liquor spraying into, except sulfur trioxide to be removed, also wants scrubbing CO_2；For sulfur dioxide, The removal efficiency of sulfur trioxide is different.In the case of reacting completely, the mole of corresponding oxysulfide is also 1600mol； In view of reacting incomplete factor, according to 95% complete Response calculation, remove oxysulfide 1600*95%=1519mol altogether；

Due to generally oxysulfide measurement apparatus will not be installed between first grade desulfurizing device and two-grade desulfurizing atomising device, press According to each 50% estimation of mole of sulfur dioxide, sulfur trioxide in the oxysulfide of removing, corresponding mean molecule quantity is：Dioxy Change sulfur molecule amount 64*50%+ sulfur trioxide molecular weight 80*50%=72.The quality of corresponding oxysulfide is 1519*72= 109368g=109368000mg；

According to 33000000Nm³/ h flow rate calculation, in this hour, the average decrease estimation of corresponding sulfoxide concentration For 109368000/3300000=33.1mg/Nm³；

Calculate for sulfur trioxide according to 50% mole in removing oxysulfide, the sulfur trioxide mole of removing is 1519*50%=759.5 mole；Corresponding sulfur trioxide quality is 759.5*80=60760g=60760000mg；

According to 33000000Nm³/ h flow rate calculation, in this hour, the average decrease estimation of corresponding sulfur trioxide concentration For 60760000/3300000=18.4mg/Nm³；The average decrease of corresponding sulfur dioxide concentration is estimated as 33.1-18.4 =14.7mg/Nm³；

If neat stress sulfur trioxide concentration is according to 15.3mg/Nm³Calculate, not in the flue gas before the method process The concentration of emission of sulfur trioxide is 18.4+15.2=33.6mg/Nm³；If the removal efficiency to sulfur trioxide of original desulfurizing tower is 30% calculating, then the sulfur trioxide concentration of former flue gas is 33.6/ (1-30%)=48.0mg/Nm³.

Overall desulfurizer device is (48.0-15.3)/48.0=68.1% to the removal efficiency of sulfur trioxide.

Under corresponding operating mode, spraying into 3.5 cubic metres per hour, in the case of the sodium carbonate liquor of 5% mass concentration, right In the flue gas of Limestone-gypsum Wet Flue Gas Desulfurization Process technique discharge, 33.1mg/Nm about can be reduced again³Sulfur oxides emissions concentration.

Embodiment 2

The device of the deep removal sulfureous in flue gas oxide of the present embodiment, as shown in figure 3, difference from Example 1 exists In：In desulfurizing tower 1, it is additionally provided between the one-level highest spraying layer 6 and two-grade desulfurizing atomising device 7 of first grade desulfurizing spray equipment Demister 16, described demister 16 is one-level demister；Along flow of flue gas direction, this demister 16 is provided with matching used demisting Device flusher 17.It is arranged on the two-stage demister difference of the demister 8 between two-grade desulfurizing atomising device 7 and exhanst gas outlet 3 For two grades, three-level demister.

The method of the deep removal sulfureous in flue gas oxide of the present embodiment, using above-mentioned deep removal sulfureous in flue gas oxidation The device of thing.The method difference from Example 1 of the present embodiment is：The desulfurizing agent of two-grade desulfurizing is sodium hydroxide, is made into Solution uses.

The device of the deep removal sulfureous in flue gas oxide of the present embodiment, has three-level demister altogether in desulfurizing tower；Hydrogen-oxygen After change sodium solution is mixed with compressed air, micron-sized atomized drop is formed by two-grade desulfurizing atomising device；For controlling demisting The water content of flue gas after device, the atomizing particle size of two-grade desulfurizing atomising device controls between 10-100 micron.

Embodiment 3

The device of the deep removal sulfureous in flue gas oxide of the present embodiment, as shown in figure 4, difference from Example 1 exists In：First grade desulfurizing in one-level liquid dispensing device join liquid pool 10 pass through one-level liquid distribution pipe road directly and desulfurizing tower recycle slurry liquid pool 4 It is connected, described one-level liquid distribution pipe road is provided with one-level solution feed pump 11, for first grade desulfurizing being joined the slurry of the Calcium Carbonate in liquid pool 10 Liquid directly fills into recycle slurry liquid pool；I.e. the one-level highest spraying layer 6 in first grade desulfurizing spray equipment is no longer directly and first grade desulfurizing Join liquid pool 10 to be connected, be only used for spraying into the loop slurry in recycle slurry liquid pool 4 in desulfurizing tower 1.

Meanwhile, eliminate compressed air reservoir and supporting pipeline in graduation two liquid device, directly adopt graduation two liquid pump Two-grade desulfurizing is joined the desulfurizing agent solution of two-grade desulfurizing in liquid pool 13 or serosity through two-grade desulfurizing atomising device high-pressure atomization by 15 Spray in desulfurizing tower.

The method of the deep removal sulfureous in flue gas oxide of the present embodiment, using above-mentioned deep removal sulfureous in flue gas oxidation The device of thing.The method difference from Example 1 of the present embodiment is：The desulfurizing agent of two-grade desulfurizing is calcium hydroxide, is made into Serosity uses.Directly two-grade desulfurizing is joined through two-grade desulfurizing atomising device by calcium hydroxide slurry in liquid pool using graduation two liquid pump High-pressure atomization sprays in desulfurizing tower, and atomizing particle size controls between 1000-1500 micron.

Calcium hydroxide slurry atomized drop is unsuitable too small, otherwise can lead to demister fouling.The present embodiment is mainly used in adjusting Section discharge flue gas sulfur dioxide concentration, that is, pass through adjust two-grade desulfurizing calcium hydroxide slurry spray into flow and/or concentration, Control the sulfur dioxide concentration of desulfurizing tower exiting flue gas, calculate and method of adjustment is with embodiment 1.

Embodiment 4

The device of the deep removal sulfureous in flue gas oxide of the present embodiment, as shown in figure 5, difference from Example 1 exists In：Eliminate the demister between two-grade desulfurizing atomising device and exhanst gas outlet and supporting mist eliminator flushing device；

In desulfurizing tower 1, between the one-level highest spraying layer 6 and two-grade desulfurizing atomising device 7 of first grade desulfurizing spray equipment It is additionally provided with demister 16, described demister 16 is two-stage demister；Along flow of flue gas direction, every grade of demister 16 is equipped with supporting The mist eliminator flushing device 17 using；

The exhanst gas outlet 3 of desulfurizing tower 1 is connected with horizontal flue 18, is provided with horizontal flue demister in described horizontal flue 18 19；Along flow of flue gas direction, horizontal flue demister 19 is provided with matching used mist eliminator flushing device 20；Described horizontal flue Demister 19 bottom is connected with collecting tank 21 by pipeline, and it is de- that described collecting tank passes through collection liquid pump 22, defecator 23 and two grades Sulfur is joined liquid pool and is connected.Collecting tank collects the liquid that horizontal flue demister intercepts, after collection liquid pump, defecator, clear liquid Fill into two-grade desulfurizing and join liquid pool and be used for preparing sodium bicarbonate solution, turbid liquid drains into desulfurizing tower interior circulation slurry pool.

The method of the deep removal sulfureous in flue gas oxide of the present embodiment, using above-mentioned deep removal sulfureous in flue gas oxidation The device of thing.The method difference from Example 1 of the present embodiment is：The desulfurizing agent of two-grade desulfurizing is sodium bicarbonate, is made into Solution uses.After sodium hydroxide solution is mixed with compressed air, micron-sized atomized liquid is formed by two-grade desulfurizing atomising device Drip；For controlling the water content of flue gas after horizontal flue demister, the atomizing particle size of two-grade desulfurizing atomising device controls in 10- Between 100 microns.

After the present embodiment filters to the liquid collecting of horizontal flue demister, using clear liquid as desulfurizing agent solution supplementary water, one Aspect saves moisturizing, on the other hand realizes desulfurizing agent and recycles, saves desulfurizing agent usage amount.In horizontal flue, smoke distribution is more Uniformly, demister is conducive to preferably to remove the drop in flue gas.Two-grade desulfurizing atomising device is arranged in demister in desulfurizing tower Afterwards, arrangement space is relatively abundant, and between two-grade desulfurizing atomising device and horizontal flue demister, distance can keep farther out, taking off Sulfur agent drop and small acid drop, sulfur dioxide gas etc. can more fully mix, have more fully reaction compartment and In the response time, be conducive to deep removal oxysulfide.

In the method for deep removal sulfureous in flue gas oxide of the present invention, such as only control the concentration of emission of sulfur dioxide, institute Some calculation procedures can carry out calculating according to scrubbing CO_2 can (circular controls three oxygen with embodiment 1 Change the computational methods of the concentration of emission of sulfur).Sulfur trioxide can be removed in view of in running simultaneously, will consider that sulfur trioxide removing is right In the impact of sulfur dioxide removal rate, calculating process is modified.When requiring to control respectively sulfur dioxide and sulfur trioxide row In the case of putting concentration, then need to calculate respectively and meet sulfur dioxide and the corresponding two-grade desulfurizing of sulfur trioxide concentration of emission requirement The adjustment flow of desulfurizing agent solution or serosity, takes sum of the two, according to sulfur dioxide, sulfur trioxide removal efficiency situation through appropriateness After correction, the desulfurizing agent solution as two-grade desulfurizing or the actual adjustment flow of serosity.

Claims

1. a kind of method of deep removal sulfureous in flue gas oxide it is characterised in that：Including making flue gas from lower in desulfurizing tower and On carry out first grade desulfurizing and two-grade desulfurizing successively；The desulfurizing agent of first grade desulfurizing is Calcium Carbonate, is taken off with flue gas as a slurry Reaction of Salmon-Saxl, falls into the recycle slurry liquid pool of desulfurization tower bottom, circulates for first grade desulfurizing after reaction；

The desulfurizing agent of two-grade desulfurizing is sodio desulfurizing agent, Mg-base desulfurizing agent, potassio desulfurizing agent or calcium hydroxide, with solution or serosity Form is atomized in the purifying smoke after spraying into first grade desulfurizing and carries out desulphurization reaction, falls into recycle slurry liquid pool, circulate and be used for after reaction First grade desulfurizing；

Spray into flow and/or concentration by adjust the calcium carbonate serosity that newly supplements of first grade desulfurizing, control in recycle slurry liquid pool and follow The pH value of ring serosity is 4.0～6.5；Spray into flow and/or concentration by adjust the desulfurizing agent solution of two-grade desulfurizing or serosity, Control the sulfoxide concentration of desulfurizing tower exiting flue gas.

2. deep removal sulfureous in flue gas oxide according to claim 1 method it is characterised in that：In first grade desulfurizing, The calcium carbonate serosity newly supplementing is injected directly into flue gas and carries out desulphurization reaction, or is directly added in recycle slurry liquid pool.

3. deep removal sulfureous in flue gas oxide according to claim 1 method it is characterised in that：Described sodio desulfurization Agent is sodium hydroxide, sodium carbonate or sodium bicarbonate；Described Mg-base desulfurizing agent is magnesium hydroxide or magnesium carbonate；Described potassio desulfurizing agent For potassium hydroxide, potassium carbonate or potassium bicarbonate.

4. deep removal sulfureous in flue gas oxide according to claim 1 method it is characterised in that：By adjusting two grades The desulfurizing agent solution of desulfurization or serosity spray into flow and/or concentration, control the sulfoxide concentration of desulfurizing tower exiting flue gas Method comprises the following steps：

1) the target gas levels actual measured value according to desulfurizing tower exiting flue gas and the difference of target control value, are multiplied by flue gas stream Value, calculates the departure of desulfurizing tower exit object gas；

2) departure of desulfurizing tower exit object gas is multiplied by the alkali sulfur ratio of setting, calculates and need two grades of adjustment to take off The amount of the desulfurizing agent of sulfur；Described alkali sulfur ratio is calcium sulfur ratio, sodium sulfur ratio, magnesium sulfur ratio or potassium sulfur ratio；

3) the adjustment desulfurizing agent solution of two-grade desulfurizing or serosity spray into flow and/or concentration, the adjustment of the desulfurizing agent being sparged into Amount be not less than step 2) gained need adjustment desulfurizing agent amount.

5. deep removal sulfureous in flue gas oxide according to claim 4 method it is characterised in that：Described object gas For sulfur dioxide and/or sulfur trioxide.

6. a kind of device of deep removal sulfureous in flue gas oxide, including desulfurizing tower, be provided with below described desulfurizing tower gas approach, Top be provided with exhanst gas outlet it is characterised in that：It is sequentially provided with from bottom to top between gas approach and exhanst gas outlet in desulfurizing tower First grade desulfurizing spray equipment and two-grade desulfurizing atomising device, described first grade desulfurizing spray equipment includes setting gradually from bottom to top Loop slurry spraying layer and one-level highest spraying layer, described one-level highest spraying layer is used for spraying into the carbon newly supplementing into desulfurizing tower Sour calcium serosity；Described two-grade desulfurizing atomising device is used for spraying into sodio desulfurizing agent, Mg-base desulfurizing agent, potassio to desulfurizing tower is atomization The solution of desulfurizing agent or calcium hydroxide or serosity；Desulfurization tower bottom is provided with recycle slurry liquid pool, sprays dress for access first grade desulfurizing Put the material spraying into two-grade desulfurizing atomising device, described loop slurry spraying layer is connected with recycle slurry liquid pool, follow for spray Ring serosity.

7. deep removal sulfureous in flue gas oxide according to claim 6 device it is characterised in that：One in desulfurizing tower It is provided with demister between level desulfurization spray equipment and two-grade desulfurizing atomising device.

8. the deep removal sulfureous in flue gas oxide according to claim 6 or 7 device it is characterised in that：In desulfurizing tower It is provided with demister between two-grade desulfurizing atomising device and exhanst gas outlet.

9. the deep removal sulfureous in flue gas oxide according to claim 6 or 7 device it is characterised in that：Desulfurizing tower Exhanst gas outlet is connected with flue, and described flue is provided with flue demister or wet electrical dust precipitator.

10. deep removal sulfureous in flue gas oxide according to claim 9 device it is characterised in that：Described flue removes Day with fog or wet electrical dust precipitator are connected with collecting tank by pipeline, are intercepted by flue demister or wet electrical dust precipitator for collecting Liquid.