The device and method of sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas
Technical field
The invention belongs to atmosphere pollution Treatment process field, particularly relate to the device and method of sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas.
Background technology
Coal-fired process produces substantial amounts of pollutant, wherein owing to coal containing a certain amount of element sulphur, therefore the flue gas of final discharge can generate certain density SO2And SO3。
SO3Formation mechanism mainly include with lower part, in the combustion process of burner hearth, in coal, a part of element sulphur is converted into SO3;Flue gas is in back-end surfaces heat transfer process, by metal pipe-wall, the catalysed oxidn of flying dust, a part of SO2SO can be oxidized to3;For the unit of newly-increased SCR denitration device, denitrating catalyst also has the strongest catalysed oxidn so that a part of SO2It is oxidized to SO3.Generally for not installing the coal unit of denitrification apparatus, SO3Production rate account for the 1% of total sulfur content;For installing the unit of SCR denitration device, SO3Production rate higher, generally can account for the 1.5~2% of total sulfur content.
SO3Harm be mainly manifested in following aspect: one, SO3Concentration raise, cause the generation concentration of ammonium hydrogen sulfate to increase, cause the minimum continuous spray ammonia temperature of denitrification apparatus to raise, cause SCR denitration device cannot put into operation under low loading conditions, the decline of the availability of denitrification apparatus.Second, SO3Low-temperature zone at air preheater causes acid dew point in flue gas to raise, and the cold end corrosion of air preheater is serious, and under SCR service condition, the generation of ammonium hydrogen sulfate easily causes air preheater blocking, causes the running resistance of air preheater to rise, and equipment life declines.3rd, SO3After entering wet desulphurization, easily form aerosol, cause chimney finally to discharge " blue smoke ", " plume hangover " phenomenon, sense organ extreme difference, simultaneously SO3Directly discharge be the main source causing acid rain.
SO at present3Main removing means are Wet Flue Gas Desulfurization Technique, wet static dedusting technology etc., but after above-mentioned technology is arranged in electrostatic precipitation, it is ensured that finally it is discharged into the SO of air3Amount reduces, but cannot eliminate SO3To front end denitrification apparatus and the harm of air preheater.
Summary of the invention
The first object of the present invention is to provide the device of sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas, has device with solution at present and cannot eliminate SO3To front end denitrification apparatus and the technical problem of the harm of air preheater.
The second object of the present invention is to provide the method for sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas, and the method that has at present with solution cannot eliminate SO3Hazard Technology problem to front end denitrification apparatus and air preheater.
In order to realize above-mentioned first purpose, the present invention provides the device of sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas, comprising:
Alkaline absorbent atomising device, described alkaline absorbent atomising device includes:
Absorbent storage tank, described absorbent storage tank is used for storing liquid sulphur trioxide absorbent;
Absorbent delivery pump, described absorbent delivery pump is provided with absorbent delivery pump entrance and the outlet of absorbent delivery pump;Absorbent delivery pump entrance is connected with absorbent storage tank by pipeline;
Flow control valve, flow control valve is by pipeline and absorbent delivery pump outlet;
Twin spray gun, twin spray gun and flow control valve pass through pipeline connection;In alkali liquor jet atomization removing flue gas, the device of sulfur trioxide also includes:
Out of stock gas approach, one end of described out of stock gas approach is smoke inlet, and the other end is exhanst gas outlet;Described twin spray gun is arranged in described out of stock gas approach;
Reducing agent ejecting gun, described reducing agent ejecting gun is arranged in described out of stock gas approach;
Spoiler, described spoiler is fixed in described out of stock gas approach, is 25 degree~75 degree with the angle of the axis of out of stock gas approach;The axis of described reducing agent ejecting gun is vertical with spoiler plane;Described twin spray gun is arranged on the top of spoiler;
Out of stock reactor, described out of stock reactor connects with the exhanst gas outlet of out of stock gas approach.
The device of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, further, alkaline absorbent atomising device also includes alkaline absorbent air mix facilities, described alkaline absorbent air mix facilities and described pipeline connection.
In present invention alkali liquor as above jet atomization removing flue gas, the device of sulfur trioxide, further, also includes that air preheater, described air preheater connect with the gas outlet of out of stock reactor.
In order to realize above-mentioned second purpose, the present invention provides the method for sulfur trioxide in a kind of alkali liquor jet atomization removing flue gas, utilizes the device of sulfur trioxide in as above alkali liquor jet atomization removing flue gas described in any one to carry out, comprises the following steps:
Liquid sulphur trioxide absorbent is stored in absorbent storage tank in liquid form, is delivered to twin spray gun through absorbent delivery pump, and by the flow of Flux Valve Control absorbent, sulfur trioxide absorption agent is sprayed after twin spray gun is atomized;Flue gas is entered by the smoke inlet of out of stock gas approach, is formed eddy current by the effect of spoiler and reducing agent ejecting gun;Sulfur trioxide absorption agent is sprayed into eddy current by twin spray gun, it is achieved flue gas and the uniform blending of sulfur trioxide absorption agent, completes SO3Elimination reaction.
The method of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, it is preferable that described liquid sulphur trioxide absorbent is aqueous slkali.
The method of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, it is preferable that described alkali is sodium carbonate Na2CO3, sodium sulfite Na2SO3With sodium bicarbonate NaHCO3In one, two or more;The mass concentration 5~40% of aqueous slkali.
The method of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, it is preferable that aqueous slkali is entered containing SO by twin lance ejection with the form of atomized drop3Flue gas in, mist droplet particle size scope is 10 μm~150 μm.
The method of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, it is preferable that with Na+:SO3Meter, aqueous slkali and SO in flue gas3The chemical molar equivalent ratio of removing amount is 1.0~4.0.
The method of sulfur trioxide in present invention alkali liquor as above jet atomization removing flue gas, it is preferable that the liquid sulphur trioxide absorbent time of staying in flue gas is 0.1~10 second, flue-gas temperature 120~450 DEG C.
The invention has the beneficial effects as follows:
The purpose of the present invention is high efficiency SO of a kind of flue gas front end3Removing sulfuldioxide, can effectively remove the sulfur trioxide in flue gas, reduces SO3Concentration, reduce its to denitrification apparatus, the harm of air preheater, reduce the harm to environment simultaneously.
1、SO3Removal efficiency is high.After utilizing twin spray gun to be atomized by liquid sulphur trioxide absorbent, it is easy to form the drop of small particle, suitable stoichiometric ratio, the time of staying, mixed uniformly under the conditions of, the SO in absorbent droplet and flue gas3Carry out quick mass transfer and chemical reaction process, it is possible to achieve high removal efficiency.
2, system is simple, high with denitrating system integrated level, to boiler without negative effect.This technology is by sorbent injection location arrangements at SCR denitration device entrance, and the mixing arrangement of available denitrification reducing agent is strengthened absorbent and mixed (reducing agent ejecting gun and spoiler) with the uniform of flue gas, it is achieved with the combination of denitrification apparatus, it is achieved SO3Efficient removal, the most effectively alleviate SO3To denitrating catalyst and the harm of air preheater, and product is the solid salt that can be trapped by downstream cleaner unit, to boiler controller system without negative effect.
3, construction costs and operating cost are low.This technical equipment is simplified, and invests low, and operating alkali liquor consumable goods is the industrial chemicals of routine, it is easy to buying, cheap, operating cost is low, compares the SO such as wet-esp3Removing equipment, all has greater advantage in terms of construction costs and operating cost.
Additionally, remove SO with solid particle absorbent3Process ration the invention have the advantages that
Use alkali liquor atomization process, the absorbent of outsourcing can be dissolved into liquid, use two-fluid spray gun atomized liquid, therefore the particle diameter not requirement to absorbent afterwards;Size droplet diameter after two-fluid spray gun is atomized is uniform and easily controllable, it is simple to realize higher removal efficiency;And the method using solid particle directly to spray, need buying to specify the solid absorbent (price is higher) of particle diameter, or increase grinds system (system complex), coarse granule is milled into fine particle.Using liquid atomization technique, drop flashes to rapidly solid particle, discharges due to gas in evaporation process, and solid particles surface can form certain microcellular structure, improve response area, by helping raising efficiency.The particle surface smoother that dry method uses, specific surface area is relatively low.Easily there are the problems such as blocking, abrasion in the process of pneumatic transmission of dry powder, and reliability is poor.Employing liquid carries, skill level, and reliability is high.
Accompanying drawing explanation
By the detailed description made in conjunction with the following drawings, above-mentioned and/or other aspects of the present invention and advantage will be apparent from and be easier to understand, and these accompanying drawings the most schematically, are not limiting as the present invention, wherein:
Fig. 1 is that the alkali liquor jet atomization of an embodiment of the present invention removes the device and method schematic diagram of sulfur trioxide in flue gas;
Fig. 2 is the close-up schematic view of 1;
Fig. 3 is the schematic top plan view of Fig. 2.
In accompanying drawing, the list of parts representated by each label is as follows:
1, liquid sulphur trioxide absorbent, 2, absorbent storage tank, 3, absorbent delivery pump, 4, alkaline absorbent air mix facilities, 5, flow control valve, 6, twin spray gun, 7, denitration gas approach, 8, Benitration reactor, 9, spoiler, 10, flue gas eddy current, 11, reducing agent ejecting gun, 12, former flue gas, 13, neat stress.
Detailed description of the invention
Hereinafter, the embodiment of the device and method of sulfur trioxide in the alkali liquor jet atomization removing flue gas of the present invention is described with reference to the accompanying drawings.
The embodiment recorded at this is the specific detailed description of the invention of the present invention, for the design of the present invention is described, is all explanatory and exemplary, should not be construed as the restriction to embodiment of the present invention and the scope of the invention.In addition to the embodiment recorded at this, those skilled in the art can also use other technical scheme obvious based on the application claims and description disclosure of that, and these technical schemes include using the technical scheme making any obvious substitutions and modifications to the embodiment recorded at this.
The accompanying drawing of this specification is schematic diagram, aids in illustrating the design of the present invention, it is schematically indicated the shape of each several part and mutual relation thereof.Note that the structure of each parts for the ease of clearly showing the embodiment of the present invention, do not draw according to identical ratio between each accompanying drawing.Identical reference marker is used for representing identical part.
It is an object of the invention to combine SO3In the reactivity that different temperatures is interval, utilize atomization technique by alkaline absorbent solution (sodium carbonate Na2CO3, sodium sulfite Na2SO3, sodium bicarbonate NaHCO3Mixed solution) it is injected in SCR denitration gas approach, fully blend with flue gas, by alkaline absorbent solution and SO3Between chemical reaction, removing flue gas in SO3。
Main chemical reactions involved in the present invention is as follows:
Na2CO3+SO3=Na2SO4+CO2
Na2SO3+SO3=Na2SO4+SO2
NaHCO3+SO3=NaHSO4+CO2
Above-mentioned different alkaline absorbent (sodium carbonate Na2CO3, sodium sulfite Na2SO3, sodium bicarbonate NaHCO3Mixed solution) all can be with SO3There is chemical reaction, but reaction rate, reactivity have bigger difference.According to SO3Concentration and total exhaust gas volumn control the straying quatity of absorbent, it is achieved SO3Efficient removal.SO in flue gas3In the range of concentration 0~400ppm, SO can be realized395% the highest removal efficiency.
Alkaline absorbent is to other pollutant (SO in flue gas2, HCl, HF etc.) all have certain removing effect, for different flue gas compositions, need to combine proportioning (the sodium carbonate Na to alkaline absorbent2CO3, sodium sulfite Na2SO3, sodium bicarbonate NaHCO3Mixed solution) it is adjusted, it is achieved absorbent is to SO3Selective efficient removal, reduces the consumption of absorbent simultaneously.For realizing SO high in bigger flue cross section3Removal efficiency, this technology requires that absorbent droplet uniformly blends with flue gas, therefore drop atomizing effect, Flow Field Distribution is had high requirement.
Fig. 1, Fig. 2 and Fig. 3 illustrate that the alkali liquor jet atomization of an embodiment of the present invention removes the device of sulfur trioxide in flue gas, comprising:
Alkaline absorbent atomising device, described alkaline absorbent atomising device includes:
Absorbent storage tank 2, described absorbent storage tank is used for storing liquid sulphur trioxide absorbent 1;
Absorbent delivery pump 3, described absorbent delivery pump 3 is provided with absorbent delivery pump entrance and the outlet of absorbent delivery pump;Absorbent delivery pump entrance is connected with absorbent storage tank 2 by pipeline;
Flow control valve 5, flow control valve 5 is by pipeline and absorbent delivery pump outlet;
Twin spray gun 6, twin spray gun 6 and flow control valve 5 pass through pipeline connection;In alkali liquor jet atomization removing flue gas, the device of sulfur trioxide also includes:
Out of stock gas approach 7, one end of described out of stock gas approach is smoke inlet, and the other end is exhanst gas outlet;Described twin spray gun 6 is arranged in described out of stock gas approach 7;
Reducing agent ejecting gun 11, described reducing agent ejecting gun 11 is arranged in described out of stock gas approach 7;
Spoiler 9, described spoiler 9 is fixed in described out of stock gas approach 7, is 25 degree~75 degree with the angle of the axis of out of stock gas approach 7;The axis of described reducing agent ejecting gun 11 is vertical with spoiler 9 plane;Described twin spray gun 6 is arranged on the top of spoiler 9;
Out of stock reactor 8, described out of stock reactor 8 connects with the exhanst gas outlet of out of stock gas approach 7.
In a kind of specific embodiment, also include that air preheater, described air preheater connect with the gas outlet of out of stock reactor.
In the alkali liquor jet atomization removing flue gas of the above embodiment of the present invention in the device of sulfur trioxide, in order to the sulfur trioxide absorption agent in absorbent storage tank is carried out on-line dilution, improvement further to above-described embodiment, alkaline absorbent atomising device also includes alkaline absorbent air mix facilities 4, described alkaline absorbent air mix facilities 4 and described pipeline connection.It is delivered to the amount of the clear water of pipeline by regulation alkaline absorbent air mix facilities 4, controls the concentration after sulfur trioxide absorption dilution agent.
Utilize the sulfur trioxide removal methods that in alkali liquor jet atomization as above removing flue gas, the device of sulfur trioxide is carried out, comprise the following steps:
Liquid sulphur trioxide absorbent is stored in absorbent storage tank in liquid form, is delivered to twin spray gun through absorbent delivery pump, and by the flow of Flux Valve Control absorbent, sulfur trioxide absorption agent is sprayed after twin spray gun is atomized;Flue gas is entered by the smoke inlet of out of stock gas approach, is formed eddy current by the effect of spoiler and reducing agent ejecting gun;Sulfur trioxide absorption agent is sprayed into eddy current by twin spray gun, it is achieved flue gas and the uniform blending of sulfur trioxide absorption agent, completes SO3Elimination reaction.
In a kind of preferred embodiment, described liquid sulphur trioxide absorbent is aqueous slkali.In a more preferred embodiment, described alkali is sodium carbonate Na2CO3, sodium sulfite Na2SO3With sodium bicarbonate NaHCO3In one, two or more;The mass concentration 5~40% of aqueous slkali.
In a kind of preferred embodiment, aqueous slkali is entered containing SO by twin lance ejection with the form of atomized drop3Flue gas in, mist droplet particle size scope is 10 μm~150 μm.
In a kind of preferred embodiment, with Na+:SO3Meter, aqueous slkali and SO in flue gas3The chemical molar equivalent ratio of removing amount is 1.0~4.0.
In a kind of preferred embodiment, the liquid sulphur trioxide absorbent time of staying in flue gas is 0.1~10 second, flue-gas temperature 120~450 DEG C.
Embodiment
1
Below as a example by certain 300MW coal unit, in conjunction with accompanying drawing, concrete structure, operation principle and the work process of the present invention are further described.
Denitration entrance flue gas temperature 380 DEG C, SO3Concentration 40ppm, SO2Concentration 2000ppm, according to the basic parameter of flue gas, the quality proportioning of the alkaline solution of employing is (sodium carbonate Na2CO3: sodium sulfite Na2SO3: sodium bicarbonate NaHCO3=1:2:1), the total salt mass concentration utilizing the solution prepared is 30%.
According to solution ratio and smoke components, the layout of combined process device, it is desirable to realize the SO of 95%3Removal efficiency, determines total chemical reaction equivalent proportion Na+:SO3=2:1, ensures SO by higher stoichiometric ratio3High removal efficiency.
As it is shown in figure 1, the SO in a kind of alkali liquor injection removing flue gas3Process system, liquid sulphur trioxide absorbent is stored in absorbent storage tank in liquid form, being delivered to twin spray gun through absorbent delivery pump, by the flow of Flux Valve Control absorbent, sulfur trioxide absorption agent is sprayed after twin spray gun is atomized;Former flue gas 12 is entered by the smoke inlet of out of stock gas approach, is formed flue gas eddy current 10 by the effect of spoiler and reducing agent ejecting gun;Sulfur trioxide absorption agent is sprayed into eddy current by twin spray gun, it is achieved flue gas and the uniform blending of sulfur trioxide absorption agent, completes SO3Elimination reaction.Final neat stress 13 is discharged by Benitration reactor 8.
It is illustrated in figure 2 the specific embodiments of alkali liquor spray gun.Denitration gas approach cross section is the rectangle of 2.6mx11m, configures 8 groups of twin spray guns 6 altogether, it is ensured that alkali liquor injection coverage is sufficiently large.Alkali liquor atomizing particle size is 50 μm, is arranged in by spray gun at spoiler 9, and flue gas forms flue gas eddy current 10 after spoiler, and volume is inhaled periphery flue gas, added the blending of strong basicity droplet and flue gas, it is ensured that reducing agent and SO3Fully reaction.
The SO of this case history3Removal efficiency 96%, and the solid particle generated by absorbent accounts for flue gas flying dust total amount mass ratio less than 0.5%, the denitrating catalyst in downstream will not be produced considerable influence.
Embodiment
2
The present embodiment is denitration entrance flue gas temperature 320 DEG C, SO with the difference of embodiment 13Content 20ppm, under design condition, SO3Removal efficiency 85%, use alkali liquor absorption agent mix proportion scheme be (sodium carbonate Na2CO3: sodium sulfite Na2SO3 =1:1.5), total salt mass concentration of alkali liquor is 20%, and the atomizing particle size of alkaline absorbent is 40 μm, designs stoichiometric ratio Na+:SO3=1.5:1.Measure according to reality, under the actual operating mode that puts into operation, SO3Removal efficiency be 88%.
Each technical characteristic of above-mentioned disclosure is not limited to disclosed with further feature combination, those skilled in the art also can carry out between each technical characteristic according to the purpose of invention other combine, be as the criterion realizing the purpose of the present invention.