CN205073865U - Hierarchical absorption desulphurization unit of ammonia - ammonium sulfate method - Google Patents

Abstract

The utility model discloses a graded absorption desulfurization device for ammonia-ammonium sulfate method, which comprises a flue gas desulfurization absorption tower, an absorption liquid circulation tank, a dilute slurry circulation tank and a wet electric dust collector; the flue gas desulfurization absorption tower includes a bottom-up Concentrated slurry circulation tank, concentrated pre-absorption section, absorption section, dilute slurry washing section and demister section; the concentrated pre-absorption section includes at least one layer of concentrated slurry spray layer, and the absorption section includes an absorption liquid cyclone demister liquid collector and at least one layer of absorption liquid spray layer, the thin slurry water washing section includes a thin slurry cyclone demist liquid collector and a thin slurry spray layer, and the mist removal section includes a mist eliminator and a mist eliminator flushing spray layer. The utility model completes the processes of flue gas cooling, grading defogging and absorption, and segmental oxidation in the absorption tower. By adjusting the position of the ammonia addition point, the ammonia utilization rate is improved, and the traditional desulfurization absorption tower is segmented, but the slurry in each segment is seriously carried. As a result, the slurry concentration control in each section is not ideal, and the aerosol content of the net flue gas aerosol is too high.

Description

A kind of hierarchical absorption desulfurization device of ammonia-ammonium sulfate method

technical field

The utility model relates to a desulfurization device, in particular to a hierarchical absorption desulfurization device of an ammonia-ammonium sulfate method, which is a flue gas desulfurization device suitable for the ammonia-ammonium sulfate method.

Background technique

Ammonia-ammonium sulfate method flue gas desulfurization technology is a mainstream desulfurization process in the chemical industry, which effectively solves the problem of waste ammonia water (with a concentration of about 5%) in the enterprise, and is used to produce ammonium sulfate, realizing "treatment with waste". Waste, comprehensive utilization".

The current ammonia-ammonium sulfate desulfurization technology has the following shortcomings in engineering application:

1) The utilization rate of ammonia is not high, and the escape of ammonia is high.

The ammonia consumption of currently operating ammonia-ammonium sulfate desulfurization devices is generally about 1.05 to 1.15 times the theoretical calculation. Considering that a 240t/h boiler burns coal with 1% sulfur content (the annual operating time is 8000 hours), The annual desulfurization agent (ammonia water) dosing amount in the desulfurization device is higher than the theoretical value, and the increased operating cost is about 700,000 yuan; at the same time, the excessive dosing of desulfurization agent (ammonia water) increases the generation of aerosols.

2) The aerosol content of the flue gas is high, and the smoke plume is seriously tailed.

In the ammonia-ammonium sulfate desulfurization process, the water vapor in the flue gas at the outlet of the desulfurization tower is mostly in a saturated state, and at the same time it carries aerosol-grade droplets containing desulfurization absorbents. When the desulfurized clean flue gas is discharged from the chimney to the atmosphere, due to the temperature drop, the supersaturated water vapor in the flue gas condenses on the surface of the aerosol, and due to the action of gravity, "ammonium sulfate rain" is formed, and the smoke plume trails for several kilometers , forming serious visual pollution.

Utility model content

The purpose of this utility model is to solve the above problems and provide a hierarchical absorption desulfurization device which can improve the utilization efficiency of the absorbent and effectively reduce the emission of aerosols in the desulfurization flue gas.

The scheme that the utility model solves its technical problem adopts is:

A hierarchical absorption and desulfurization device of the ammonia-ammonium sulfate method, comprising a flue gas desulfurization absorption tower 1, an absorption liquid circulation tank 2, a thin slurry circulation tank 3 and a wet electrostatic precipitator 20; the flue gas desulfurization absorption tower 1 includes a self- Bottom-up concentrated slurry circulation tank 4, concentrated pre-absorption section, absorption section, dilute slurry washing section and demister section; the concentrated slurry circulation tank 4 is set at the lower part of the flue gas desulfurization absorption tower 1 as a part of the desulfurization absorption tower , the concentrated pre-absorption section includes at least one layer of concentrated slurry spray layer 12, and the absorption section includes a bottom-up absorption liquid cyclone demister liquid collector 13 and at least one layer of absorption liquid spray layer 14, the The thin slurry water washing section includes a bottom-up thin slurry cyclone defogging liquid collector 15 and a thin slurry spray layer 17, and the mist removal section includes a bottom-up mist eliminator 18 and a mist eliminator flushing spray A shower layer 19; a wet electrostatic precipitator 20 is installed on the top of the flue gas desulfurization absorption tower 1 so that the flue gas enters the wet electrostatic precipitator 20 through the flue gas outlet at the top of the flue gas desulfurization absorption tower 1; There are absorption tower oxidation air distribution pipe 10 and jet agitation distribution pipe 9 (the distribution of ammonia water is completed by jet agitation distribution pipe), the outlet of concentrated slurry circulation tank 4 passes through the concentrated slurry circulation pump 5, the concentrated slurry circulation pipe 24 and the concentrated pre-absorption section The concentrated slurry spray layer 12 is connected; the concentrated pre-absorption section is provided with a flue inlet 11, and the pre-concentrated absorption section communicates with the intake flue through the flue inlet 11, and the flue inlet 11 is located at the concentrated slurry spray Below the shower layer 12; the absorption liquid circulation tank 2 communicates with the absorption liquid spray layer 14 through the absorption liquid circulation pump 6 and the absorption liquid circulation pipe 27, and the absorption liquid swirl defogging liquid collector 13 absorbs The liquid return pipe 26 is connected with the absorption liquid circulation tank 2, and the absorption liquid falls on the absorption liquid swirl defogging liquid collector 13 after being circulated and sprayed, and is discharged from the liquid collector at the bottom of the absorption liquid swirling flow demist liquid collector The liquid port gravity flows back to the absorption liquid circulation tank 2; the lower part of the absorption liquid circulation tank 2 is provided with an absorption liquid return distribution pipe 21 and an absorption liquid circulation tank oxidation air distribution pipe 22; the thin slurry circulation tank 3 passes through the thin slurry circulation pump 7. The thin slurry circulation pipe 29 communicates with the thin slurry spray layer 17, the thin slurry swirl defogging liquid collector 15 communicates with the thin slurry circulation tank 3 through the thin slurry return pipe 28, and the thin slurry circulation spray After showering, the packing layer 16 in the water washing section falls on the dilute slurry swirl defogging liquid collector 15, and flows back to the dilute slurry circulation tank 3 by gravity from the liquid collector outlet at the lower part of the dilute slurry swirl defogging liquid collector 15.

Preferably, the concentrated pre-absorption section is provided with 1-2 layers of concentrated slurry spray layers 12, the absorption section is provided with 3-4 layers of absorption liquid spray layers 14, and the dilute slurry washing section is provided with 1 layer of dilute slurry spray layers. Layer 17.

Preferably, the oxidation air distribution pipe 10 of the absorption tower is arranged above the jet agitation distribution pipe 9 to reduce the gas-phase entrainment of ammonia; 9 are connected; the jet circulation pump 8 is arranged on the concentrated slurry jet circulation pipe 30; the concentrated slurry jet circulation pipe 30 is connected with the dilute ammonia water supply pipe at the entrance of the jet fluid circulation pump 8, and the dilute ammonia water passes through the jet circulation The role of the pump 8 is to mix the concentrated slurry uniformly in the jet circulation pipe 30 and enter the concentrated slurry circulation tank 4 through the jet stirring distribution pipe 9 .

As a further preference, filters are installed in the pipelines at the inlets of the concentrated slurry circulation pump 5 , the absorption liquid circulation pump 6 , the thin slurry circulation pump 7 and the jet circulation pump 8 .

Preferably, the oxidation air distribution pipe 22 of the absorption liquid circulation tank is arranged above the absorption liquid return distribution pipe 21 to reduce ammonia gas-phase entrainment; the absorption liquid return distribution pipe 21 communicates with the absorption liquid return pipe 26 . The absorption liquid return pipe 26 communicates with the dilute ammonia water supply pipe.

Preferably, the concentrated slurry circulation pipe 24 is provided with an ammonium sulfate removal post-treatment device branch pipe 25 at the outlet of the concentrated slurry circulation pump 5, and when the concentrated slurry in the concentrated slurry circulation tank 4 reaches a set density and concentration, sulfuric acid is injected The ammonium reprocessing unit is centrifugally dried.

Preferably, the concentrated pre-absorption section is provided with a concentrated pre-absorption section replenishment pipe 33, and the concentrated pre-absorption section liquid replenishment pipe 33 communicates with the absorption liquid circulation pipe 27 and the concentrated pre-absorption section backwash layer arranged in the concentrated pre-absorption section , regularly flush the absorbing liquid swirl defogging liquid collector 13; the absorbing section is provided with an absorbing section replenishing pipe 32, and the absorbing section replenishing pipe 32 communicates with the dilute slurry circulation pipe 29 and the absorbing section backwashing arranged in the absorbing section layer, regularly flush the dilute slurry cyclone defogging liquid collector 15.

Preferably, the absorption liquid cyclone demister liquid collector 13 and the thin slurry cyclone demist liquid collector 15 are all cyclone demist liquid collectors, and the cyclone demist liquid collector includes a cyclone demister Liquid collector bottom plate 41, multiple lifters 37, swirl 34, sieve plate 35, defogging baffle 36, downcomer support pipe 40, liquid collecting pan 39, liquid leakage hole 38 and liquid collector outlet 42 The bottom plate 41 of the swirl defogger liquid collector is provided with a liquid collector drain port 42 for connecting with the absorption liquid return pipe 26 or the thin slurry return pipe 28; On the bottom plate 41 of the liquid container, two adjacent rows of lifters 37 are arranged in a staggered manner corresponding to the vacancies; a swirl 34 is arranged inside the lifter 37, and the swirl 34 is fixed on the lifter through the sieve plate 35. On the inner wall of 37, an annular defogging baffle 36 is arranged on the top of the air lifter 37, and downcomer support pipes 40 are evenly distributed on the upper part of the air lifter 37 to support the liquid collection pan 39, and the center of the liquid collection pan 39 is set Leak hole 38 is arranged. The sieve plate 35 includes an annular bottom plate and a cylindrical vertical plate, the lower end of the cylindrical vertical plate is fixedly connected to one end of the annular bottom plate so that the longitudinal section of the sieve plate 35 is in an “L” shape, and the other end of the bottom plate is fixed to the lifter 37 On the inner wall, the upper end of the vertical plate is used to fix the swirler 34, and small holes are uniformly arranged on the bottom plate.

As a further preference, the elevation angle of the swirlers is 20-30 degrees. According to the actual operation of the flue gas desulfurization absorption, the angle of elevation angle of the swirls in the absorption liquid cyclone demist collector 13 and the dilute slurry cyclone demist collector 15 can be adjusted.

Preferably, the hierarchical absorption desulfurization device of the ammonia-ammonium sulfate method of the present invention is equipped with 1-2 layers of demisters 18; the demisters 18 can be baffle plate demisters or roof-type demisters. The flushing spray layer 18 of the demister is connected with the process water pipe 31, and the process water provided by the process water pipe 31 regularly flushes the demister 18 to ensure that the channel of the demister 18 is not blocked, and the flushing spray liquid falls into the slurry cyclone. Flow on the demister liquid collector 15, and then flow back to the thin slurry circulation tank 3 as the thin slurry to spray and replenish water.

Preferably, the flue gas desulfurization absorption tower 1 is provided with a water washing section packing layer 16 , and the water washing section packing layer 16 is arranged between the dilute slurry cyclone demister liquid collector 15 and the dilute slurry spray layer 17 .

Preferably, a super-temperature spray layer is set in the inlet flue 11 .

As another preferred solution of the present utility model, the wet electrostatic precipitator 20 can be arranged on one side of the flue gas desulfurization absorption tower 1, and the flue gas outlet at the top of the flue gas desulfurization absorption tower 1 communicates with the wet electrostatic precipitator 20 through the flue. .

The beneficial effects of the utility model:

Multiple functional sections of the hierarchical absorption desulfurization device of the ammonia-ammonium sulfate method of the utility model include a concentrated pre-absorption section, an absorption section, a dilute slurry washing section and a defogging section, and the top of the concentrated slurry circulation tank is swirled with the absorption liquid to defog and collect the liquid Between the concentrated pre-absorption section; between the absorption liquid cyclone demister liquid collector and the thin slurry cyclone demist liquid collector is the absorption section; between the dilute slurry cyclone demist liquid collector and the mist eliminator is Thin slurry water washing section; between the mist eliminator and the wet electrostatic precipitator is the mist removal section. The utility model completes the processes of flue gas cooling, grading demisting and absorption, and segmental oxidation in one absorption tower, which solves the problem that although the traditional desulfurization absorption tower is segmented, the slurry in each segment is seriously carried, which leads to unsatisfactory control of the slurry concentration in each segment and clean smoke. The aerosol content of the aerosol is too high, and the ammonia utilization rate is better improved by adjusting the position of the ammonia addition point. Ammonia utilization can reach more than 99%.

It mainly has the following beneficial effects:

1) The concentrated slurry circulation tank is equipped with an oxidation air distribution pipe, which effectively improves the oxidation efficiency of the supersaturated ammonium sulfate slurry in the ammonium sulfate removal post-treatment device; the ammonia water distribution in the concentrated slurry circulation tank is realized through the jet agitation distribution pipe, and the ammonia water is added by the jet circulation pump The pressure is injected from the nozzle on the jet stirring distribution pipe and mixed with the fluid in the concentrated slurry circulation tank. Compared with the separate ammonia water distribution pipe (the ammonia water distribution pipe is generally only equipped with distribution holes), the distribution uniformity and mixing of ammonia water are effectively improved. Effect.

2) Ammonia desulfurization generally sets the absorption liquid circulation tank in the tower, and separates it from the concentrated pre-absorption section circulating slurry by the upper inclined plate. At the same time, the cancellation of the inclined plate and the drop of the liquid level at the bottom of the absorption tower effectively reduce the height of the desulfurization tower, reducing investment costs and energy consumption.

3) Practice has proved that the concentration of particulate matter contained in the net flue gas after desulfurization is positively correlated with the concentration of the last layer of spray slurry in contact with other conditions, and a swirl is set at the bottom of the absorption section and the thin slurry washing section The demister liquid collector realizes the differentiated control of the composition, concentration, pH and oxidation degree of the slurry in the concentrated slurry circulation tank, the absorption liquid circulation tank and the thin slurry circulation tank, so that the concentration of the slurry in the thin slurry circulation tank is controlled at 1%. ~3% to reduce the concentration of particulate matter in the net flue gas after desulfurization; at the same time, the upper leakage liquid forms an absorption liquid film on the swirl, which has a certain supplementary absorption effect on SO ₂ in the flue gas.

Description of drawings

Fig. 1 is the structural representation of the hierarchical absorption desulfurization device of the utility model ammonia-ammonium sulfate method;

Fig. 2 is the structural representation of the swirl demister liquid collector in the hierarchical absorption desulfurization device of the ammonia-ammonium sulfate method of the present invention;

Fig. 3 is an A-A cross-sectional view of the cyclone demister liquid collector in Fig. 2;

Fig. 4 is the B direction diagram of Fig. 3;

In the figure, 1—flue gas desulfurization absorption tower, 2—absorption liquid circulation tank, 3—dilute slurry circulation tank, 4—concentrated slurry circulation tank, 5—concentrated slurry circulation pump, 6—absorption liquid circulation pump, 7—dilute slurry Circulation pump, 8—jet circulation pump, 9—jet stirring distribution pipe, 10—oxidation air distribution pipe of absorption tower, 11—flue inlet, 12—spray layer of concentrated slurry, 13—absorption liquid cyclone demist liquid collector , 14—absorption liquid spray layer, 15—dilute slurry cyclone defogging liquid collector, 16—water washing section filler, 17—dilute slurry spray layer, 18—demister, 19—washing spray layer of demister , 20—wet electrostatic precipitator, 21—absorption liquid return distribution pipe, 22—absorption liquid circulation tank oxidation air distribution pipe, 23—dilute ammonia water supply pipe, 24—concentrated slurry circulation pipe, 25—ammonium sulfate removal post-treatment device branch pipe , 26—absorption liquid return pipe, 27—absorption liquid circulation pipe, 28—dilute slurry return pipe, 29—dilute slurry circulation pipe, 30—concentrated slurry jet circulation pipe, 31—process water pipe, 32—absorption section rehydration pipe, 33 —Concentrated pre-absorption section liquid replenishment pipe; 34—Swirler, 35—Sieve plate, 36—Defogging baffle, 37—Lift cylinder, 38—Leakage hole, 39—Liquid collection tray, 40—Down liquid support pipe, 41—the bottom plate of the liquid collector for swirl defogging, and 42—the liquid outlet of the liquid collector.

detailed description

The utility model will be further described below in conjunction with the accompanying drawings and embodiments, but the following content does not constitute a limitation to the protection scope of the utility model.

As shown in Figures 1-4, a hierarchical absorption desulfurization device of ammonia-ammonium sulfate method includes a flue gas desulfurization absorption tower 1, an absorption liquid circulation tank 2, a dilute slurry circulation tank 3 and a wet electrostatic precipitator 20; The flue gas desulfurization absorption tower 1 includes a bottom-up concentrated slurry circulation tank 4, a concentrated pre-absorption section, an absorption section, a thin slurry washing section and a demister section. The concentrated pre-absorption section includes 1 to 2 layers of concentrated slurry spray layers 12, and the absorption section includes a bottom-up absorption liquid cyclone demister liquid collector 13 and 3 to 4 layers of absorption liquid spray layers 14, The thin slurry water washing section includes a bottom-up thin slurry cyclone defogging liquid collector 15, a water washing section packing layer 16 and a thin slurry spray layer 17, and the demister section includes a bottom-up demister The spray layer 19 is flushed by the mist device 18 and the mist eliminator; a wet electrostatic precipitator 20 is installed on the top of the flue gas desulfurization absorption tower 1 .

The concentrated slurry circulation tank 4 is arranged inside the flue gas desulfurization absorption tower 1, and as a part of the flue gas desulfurization absorption tower 1, an absorption tower oxidation air distribution pipe 10 and a jet stirring distribution pipe 9 are arranged at the lower part of the concentrated slurry circulation tank 4 (Ammonia water distribution is completed by the jet agitation distribution pipe 9), the absorption tower oxidation air distribution pipe 10 is arranged above the jet agitation distribution pipe 9, to reduce the gas phase carrying of ammonia; the upper part of the concentrated slurry circulation tank 4 is arranged on the flue gas desulfurization absorption The concentrated slurry jet circulation pipe 30 outside the tower 1 is connected with the jet stirring distribution pipe 9; the jet circulation pump 8 is arranged on the concentrated slurry jet circulation pipe 30; The entrance is connected with the dilute ammonia water supply pipe, and the dilute ammonia water passes through the action of the jet circulation pump 8, mixes evenly in the concentrated slurry jet circulation pipe 30, and then enters the concentrated slurry circulation tank 4 through the jet agitation distribution pipe 9, and the pH value of the concentrated slurry The amount of dilute ammonia water added is determined, and the pH value of the concentrated slurry in the concentrated slurry circulation tank 4 is controlled between 5.0 and 5.5. The outlet of the concentrated slurry circulation tank 4 communicates with the concentrated slurry spray layer 12 in the concentrated preabsorption section through the concentrated slurry circulation pump 5 and the concentrated slurry circulation pipe 24; a flue inlet 11 is arranged in the concentrated preabsorption section, The pre-concentration absorption section communicates with the intake flue through the flue inlet 11, the flue inlet 11 is located below the concentrated slurry spray layer 12, and the original flue gas enters the concentrated pre-absorption section through the inlet flue 11; each layer of concentrated slurry The coverage rate of the spraying layer 12 is 150% to 200%. The concentrated slurry spraying layer 12 is composed of concentrated slurry distribution pipes, nozzles and support beams. The flue gas is concentrated and pre-absorbed by spraying the concentrated slurry, and the absorption part SO ₂ , the flue gas after concentration and pre-absorption is cooled down, and enters the absorption section through the absorption liquid cyclone demisting liquid collector 13, most of the ammonium sulfate-containing droplets carried by the flue gas are intercepted by the swirl 34, along the The inner wall of the lift cylinder 37 falls into the sieve plate 35 and returns to the concentrated slurry circulation tank 4, thereby reducing the amount of ammonium sulfate carried from the concentrated pre-absorption section to the absorption section, and realizing the control of the concentration, pH value and oxidation degree of the absorption section.

The absorption liquid circulation tank 2 communicates with the absorption liquid spray layer 14 through the absorption liquid circulation pump 6 and the absorption liquid circulation pipe 27, and the spray coverage of each absorption liquid spray layer 14 is between 150% and 200%. The absorption liquid spray layer ₁₄ is composed of absorption liquid distribution pipes, nozzles and support beams, etc., one of which is a spare layer to prevent the abnormal increase of SO in the flue gas due to changes in coal quality, and the absorption liquid is swirled to remove The mist collector 13 communicates with the absorption liquid circulation tank 2 through the absorption liquid return pipe 26 . The flue gas treated in the absorption section continues to rise, and enters the thin slurry water washing section through the dilute slurry cyclone defogging liquid collector 15. Most of the ammonium sulfate-containing droplets carried by the flue gas are intercepted by the swirl 34 and flow along the riser. The inner wall of 37 falls into the sieve plate 35 and returns to the absorption section, thereby reducing the amount of ammonium sulfate carried from the absorption section to the washing section of the thin slurry, and realizing the concentration control of the washing section of the thin slurry; On the bottom plate 41 of the demister liquid collector, part of the absorbing liquid falls on the liquid collecting pan 39 of the swirling flow demist liquid collector 13, and then passes through the downcomer support tube 40 to the bottom plate 41 of the swirling flow demist liquid collector, and finally passes through the collecting liquid. The liquid outlet 42 of the liquid device flows to the absorption liquid circulation tank 2 by gravity. The absorption liquid return pipe 26 is connected with the dilute ammonia water supply pipe, and the pH value of the absorption liquid is controlled by the amount of dilute ammonia water added. After the dilute ammonia water is mixed with the absorption liquid in the absorption liquid return pipe 26, it enters the absorption liquid circulation tank 2 The absorption liquid in the backflow distribution pipe 21; the oxidation air is added into the absorption liquid circulation tank 2 through the oxidation air distribution pipe 22 of the absorption liquid circulation tank.

The thin slurry circulation tank 3 communicates with the thin slurry spray layer 17 through the thin slurry circulation pump 7 and the thin slurry circulation pipe 29, and the thin slurry swirl defogging liquid collector 15 communicates with the thin slurry return pipe 28. The thin slurry circulation tank 3 is connected; the packing layer 16 in the water washing section effectively realizes the uniform distribution of the flue gas, and at the same time intercepts part of the ammonium sulfate-containing mist particles carried in the flue gas; the thin slurry spray layer 17 is further reduced. The content of ammonium sulfate in the ammonium sulfate-containing droplet particles carried in the flue gas, while further absorbing residual SO ₂ , part of the dilute slurry falls on the bottom plate 41 of the cyclone demister liquid collector through the packing layer 16 of the water washing section after circulating spraying Part of it falls on the liquid collecting pan 39 of the thin slurry cyclone demister liquid collector 15, and then passes through the downcomer support pipe 40 to the bottom plate 41 of the cyclone demist liquid collector, and finally returns to the liquid collector through the liquid collector outlet. Thin slurry circulation tank 3.

The demister 18 and the demister flushing spray layer 19 are arranged in the demister section, the demister flushing spray layer 19 is connected with the process water pipe 31, and the process water is used to regularly flush the spray demister 18 to ensure demister The channel of the mist device 18 is not blocked, and the flushing spray liquid falls on the dilute slurry cyclone defogging liquid collector 15, and then flows back to the dilute slurry circulation tank 3 as dilute slurry spray water replenishment. The mist eliminator 18 can be a baffle plate mist eliminator or a roof type mist eliminator, with 1-2 layers.

The absorption liquid swirl defogging liquid collector 13 and the dilute slurry swirling flow defogging liquid collector 15 are all swirl flow defogging liquid collectors, and the swirling flow defogging liquid collector includes a swirling flow defogging liquid collector Bottom plate 41, a plurality of lifting cylinders 37, swirls 34, sieve plates 35, defogging baffles 36, downcomer support pipes 40, liquid collection trays 39, liquid leakage holes 38 and liquid collector discharge ports 42; The bottom plate 41 of the swirl defogger liquid collector is provided with a liquid collector drain port 42 for connecting with the absorption liquid return pipe 26 or the thin slurry return pipe 28; the bottom of the air lifter 37 is fixed on the bottom plate of the swirl flow defogger liquid collector 41, two adjacent columns of lifters 37 are in a staggered arrangement corresponding to the vacancies; a swirl 34 is arranged inside the lifter 37, and the swirl 34 is fixed on the inner wall of the lifter 37 through the sieve plate 35 , the top of the lift cylinder 37 is provided with an annular defogging baffle 36, and a downcomer support pipe 40 is evenly distributed on the top of the lift cylinder 37 for supporting the liquid collection pan 39, and a leaking liquid is arranged at the center of the liquid collection pan 39. Hole 38. The sieve plate 35 includes an annular bottom plate and a cylindrical vertical plate, the lower end of the cylindrical vertical plate is fixedly connected to one end of the annular bottom plate so that the longitudinal section of the sieve plate 35 is in an “L” shape, and the other end of the bottom plate is fixed to the lifter 37 On the inner wall, the upper end of the vertical plate is used to fix the swirler 34, and small holes are uniformly arranged on the bottom plate. The absorbing liquid swirl demist collector 13 and thin slurry swirl demist collector 15 are made of duplex stainless steel, and the swirl 34 is made of outward-facing plates. Part of the slurry falls on the swirl 34 through the leakage hole 38, forming a layer of liquid film on the surface of the swirl, which can absorb SO ₂ and dissolve the removed ammonium sulfate droplets to prevent The swirl 34 and the sieve plate 35 are crystallized and blocked.

The concentrated slurry circulation pipe 24 is provided with an ammonium sulfate-removing aftertreatment device branch pipe 25 at the concentrated slurry circulation pump 5 outlet. The device branch pipe 25 is sent to the ammonium sulfate post-treatment device for centrifugal drying.

The concentrated pre-absorption section is provided with a concentrated pre-absorption section replenishment pipe 33, and the concentrated pre-absorption section liquid replenishment pipe 33 is connected to the absorption liquid circulation pipe 27, and the concentrated pre-absorption section replenishment liquid is provided by the absorption liquid circulation tank 2 as a flushing liquid. The backwashing layer of the concentrated pre-absorption section connected with the liquid replenishment pipe 33 of the concentrated pre-absorption section regularly flushes the components such as the liquid collection plate 39, the swirl 34 and the sieve plate 35 of the absorption liquid cyclone demister liquid collector 13 to prevent Surface scaling clogs channels.

The absorption section is provided with an absorption section liquid replenishment pipe 32, and the absorption section liquid replenishment pipe 32 is connected with the thin slurry circulation pipe 29, and the absorption section liquid replenishment is provided by the thin slurry circulation tank 3 as a flushing liquid, and is communicated with the absorption section liquid replenishment pipe 32 The backwashing layer of the absorption section regularly flushes components such as the liquid collecting pan 39, the swirl 34 and the sieve plate 35 of the dilute slurry cyclone defogging liquid collector 15 to prevent fouling on the surface of the components from blocking the passage.

Filters are installed in the inlet pipes of the concentrated slurry circulation pump 5, absorption liquid circulation pump 6, thin slurry circulation pump 7, and jet circulation pump 8 to ensure that all nozzles will not be blocked to form a short circuit of flue gas. The material is made of fiberglass, and the filter screen is made of Hastelloy or corrosion-resistant non-metallic materials. The impeller material of the concentrated slurry circulation pump 5 must be resistant to abrasion. When the slurry flow in the concentrated slurry circulation pipe 24 is less than 80% of the design flow, the standby pump is automatically activated. At this time, the impeller of the concentrated slurry circulation pump 5 may be damaged.

An over-temperature spray layer is set in the inlet flue 11 to prevent damage to the internal parts of the desulfurization tower due to abnormal temperature rise of the flue gas. The spray layer pipeline should be made of duplex stainless steel, and the nozzle should be made of silicon carbide.

When the concentration of the slurry in the absorption section is too high, under the condition of satisfying the material balance, the slurry in the slurry washing section can be used as the flushing liquid in the absorbing liquid cyclone defogging liquid collector 13 .

The concentrated slurry should be a supersaturated ammonium sulfate solution with a solid content of 15% to 20%, the oxidation rate of ammonium sulfate is above 99.5%, and the pH value is between 5.0 and 5.5; The flue gas contains SO ₂ ; the dilute slurry should be controlled at a concentration of ammonium sulfate slurry below 3%. The rehydration of the thin slurry is directly supplemented by the flushing water of the mist eliminator and the flushing water of the wet electrostatic precipitator.

If the site space is not limited, the wet electrostatic precipitator 20 can be installed on the side of the flue gas desulfurization absorption tower 1, and the flue gas outlet at the top of the flue gas desulfurization absorption tower 1 is connected to the wet electrostatic precipitator 20 through the flue.

Example 1

Treat flue gas from 240t/h pulverized coal boiler, the flue gas volume is 280,000Nm ³ /h under rated working conditions, the raw flue gas temperature at the flue inlet 11 is 125°C, the SO ₂ concentration is 2500mg/Nm ³ , and the dust content is 20mg/Nm ³ . The flue gas desulfurization absorption tower 1 is made of carbon steel-lined glass flakes, 32m high and 7.2m in diameter, in which the liquid level of the concentrated slurry circulation tank 4 is controlled at 5.5m~6m, and the jet stirring distribution pipe 9 made of FRP and the absorption tower are arranged below Oxidation air distribution pipe 10, the amount of oxidation air is 1800Nm ³ /h. One layer of concentrated slurry spray layer 12 is set in the concentrated pre-absorption section, the material is 2205 duplex stainless steel, the flow rate is 400m ³ /h, and the spray coverage rate is 150%; one layer of concentrated slurry pre-absorption section is set above the concentrated slurry spray layer 12 The backwashing layer is used as the backwashing spraying layer of the absorbing liquid cyclone defogging liquid collector 13, made of high-temperature-resistant FRP, spraying intermittently, once an hour, each time lasting 3 minutes, and each time spraying 6m ³ . Absorbing liquid swirling defogging liquid collector 13 in the absorption section is made of 2205 duplex stainless steel. The diameter of the outer end of the swirl blade is 950 mm, the elevation angle is 25 degrees, and the opening ratio of the sieve plate 35 is 1.5%. The absorbing liquid swirling defogging collector The air resistance of the liquid device 13 is 350Pa, the liquid leakage rate is 0.5%, and the demisting efficiency is 85%. There are 3 layers of absorbing liquid spraying layers 14 in the absorption section, the material is FRP, the layer spacing is 2m, and the spraying volume of each layer is 400m ³ /h, the spray coverage rate of each layer is 150%, the middle layer is a spare layer, the absorption liquid is ammonium sulfate slurry with a concentration of 15%, and the backwash layer of the absorption section is set above the absorption liquid spray layer 14, and the material is FRP , intermittent spraying, spraying once an hour, each time lasting 3 minutes, each time spraying 7m ³ , and backwashing the dilute slurry cyclone demister liquid collector 15. Thin slurry swirl defogging liquid collector 15 is made of 317 stainless steel, the diameter of the outer end of the blade of the swirl is 950mm, the elevation angle is 25 degrees, the opening ratio of sieve plate 35 is 1%, and the thin slurry swirling flow defogging liquid collector 15 gas The resistance is 300Pa, the leakage rate is 0.5%, and the demisting efficiency is 90%. The height of the packing layer 16 in the washing section is 2m, which is a layer of corrugated plate packing; a thin slurry spray layer 17 is set above the packing layer 16 in the washing section, with a spray volume of 200m ³ /h, a spray coverage of 150%, and a concentration of the thin slurry. 2% ammonium sulfate slurry. The mist eliminator 18 in the mist removal section is a one-layer folded plate mist eliminator with an air resistance of 150 Pa and a mist removal efficiency of 98%. After the flue gas passes through the flue gas desulfurization absorption tower 1, it enters the wet electrostatic precipitator 20 to further remove the aerosol containing ammonium sulfate.

After the flue gas is treated by the hierarchical absorption desulfurization device of the ammonia-ammonium sulfate method in this embodiment, the discharged net flue gas is tested to obtain data:

The droplet content in the flue gas at the flue gas outlet of the flue gas desulfurization absorption tower 1 is 80 mg/Nm ³ , and the droplet content in the net flue gas at the outlet of the wet electrostatic precipitator 20 is 30 mg/Nm ³ ;

The total aerosol (dust) content in the flue gas at the flue gas outlet of the flue gas desulfurization absorption tower 1 is 10 mg/Nm ³ , and the total aerosol content in the net flue gas at the outlet of the wet electrostatic precipitator 20 is 4.9 mg/Nm ³ ;

Ammonia utilization rate is over 99%.

Example 2

The hierarchical absorption desulfurization device of the ammonia-ammonium sulfate method of embodiment 1 is transformed. During the transformation, only the swirl defogging liquid collector is adjusted, and it is respectively transformed into a device (device A ), the device (device B) that is neither provided with the absorption liquid cyclone demist collector 13 nor the dilute slurry cyclone demist collector 15 is respectively fed into the flue gas, and the flue gas volume is 270000Nm ³ /h , the concentration of SO ₂ in the flue gas is 2000mg/Nm ³ . Compared with device B, the air resistance of device A increased by 180Pa, the amount of ammonium sulfate carried from the concentrated pre-absorption section to the absorption section was reduced from 2t/h to 0.4t/h, and the concentration of the slurry in the absorption section was reduced from 30% to 12%. The total aerosol (dust) content in the clean flue gas is reduced from 40mg/Nm ³ to 20mg/Nm ³ .

The parts not involved in the utility model are all the same as the prior art or can be realized by adopting the prior art.

Although the utility model is described and illustrated by one or some special configurations, the purpose is not to limit the details, because there may be various modifications and structural changes within the scope of the patent requirements without departing from the spirit of the utility model .

Claims (10)

1. a classification Absorption Desulfurization device for ammonia ammonium sulphate process, is characterized in that comprising fume desulfurating absorption tower (1), absorbing liquid circulating slot (2), dilute slurry circulating slot (3) and wet electrical dust precipitator (20); Concentrated slurry circulating slot (4) from bottom to top, concentrated pre-absorption section, absorber portion, dilute slurry washing section and demist section is comprised in described fume desulfurating absorption tower (1); Described concentrated pre-absorption section comprises at least one deck concentrated slurry spraying layer (12), described absorber portion comprises absorbing liquid vortex-flow and defrosting liquid trap (13) from bottom to top and at least one deck absorbing liquid spraying layer (14), described dilute slurry washing section comprises dilute slurry vortex-flow and defrosting liquid trap (15) from bottom to top and dilute slurry spraying layer (17), and described demist section comprises demister (18) from below to up and mist eliminator flushing spraying layer (19); Arranging wet electrical dust precipitator (20) at fume desulfurating absorption tower (1) top makes flue gas enter wet electrical dust precipitator (20) through fume desulfurating absorption tower (1) top exhanst gas outlet; The bottom of described concentrated slurry circulating slot (4) is provided with absorption tower oxidation air distributor pipe (10) and jet mixing distributor pipe (9), and concentrated slurry circulating slot (4) is connected with the concentrated slurry spraying layer (12) in concentrated pre-absorption section through concentrated slurry circulating pump (5), concentrated slurry circulation pipe (24); Flue entrance (11) is provided with in described concentrated pre-absorption section, pre-concentration absorber portion is connected by flue entrance (11) with air inlet flue, and described flue entrance (11) is positioned at concentrated slurry spraying layer (12) below; Described absorbing liquid circulating slot (2) is connected with described absorbing liquid spraying layer (14) through absorbing liquid circulating pump (6), absorbing liquid circulation pipe (27), and described absorbing liquid vortex-flow and defrosting liquid trap (13) is connected with absorbing liquid circulating slot (2) through absorbing liquid return duct (26); Described absorbing liquid circulating slot (2) bottom is provided with absorbing liquid backflow distributor pipe (21) and absorbing liquid circulating slot oxidation air distributor pipe (22); Described dilute slurry circulating slot (3) is connected with described dilute slurry spraying layer (17) through dilute slurry circulating pump (7), dilute slurry circulation pipe (29), and described dilute slurry vortex-flow and defrosting liquid trap (15) is connected with dilute slurry circulating slot (3) through dilute slurry return duct (28).

2. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, is characterized in that described absorption tower oxidation air distributor pipe (10) is arranged on jet mixing distributor pipe (9) top; The concentrated slurry jet-loop pipe (30) of described concentrated slurry circulating slot (4) top through being arranged on fume desulfurating absorption tower (1) outside is connected with jet mixing distributor pipe (9); Described concentrated slurry jet-loop pipe (30) is provided with jet-loop pump (8); Described concentrated slurry jet-loop pipe (30) is connected with weak aqua ammonia supply pipe in the porch of jet-loop pump (8).

3. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 2, is characterized in that all being provided with filter at the porch pipeline of described concentrated slurry circulating pump (5), absorbing liquid circulating pump (6), dilute slurry circulating pump (7), jet-loop pump (8).

4. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, is characterized in that described absorbing liquid circulating slot oxidation air distributor pipe (22) is arranged on absorbing liquid backflow distributor pipe (21) top; Described absorbing liquid backflow distributor pipe (21) is connected with absorbing liquid return duct (26); Described absorbing liquid return duct (26) is connected with weak aqua ammonia supply pipe.

5. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, is characterized in that described concentrated slurry circulation pipe (24) is provided with ammonium sulfate after-treatment device arm (25) in concentrated slurry circulating pump (5) outlet.

6. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, it is characterized in that described concentrated pre-absorption section is provided with concentrated pre-absorption section liquid supplementation pipe (33), the concentrated pre-absorption section backwash layer that described concentrated pre-absorption section liquid supplementation pipe (33) is communicated with absorbing liquid circulation pipe (27) and is arranged in concentrated pre-absorption section, periodic flushing absorbing liquid vortex-flow and defrosting liquid trap (13); Described absorber portion is provided with absorber portion liquid supplementation pipe (32), the absorber portion backwash layer that described absorber portion liquid supplementation pipe (32) is communicated with dilute slurry circulation pipe (29) and is arranged in absorber portion, periodic flushing dilute slurry vortex-flow and defrosting liquid trap (15).

7. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, it is characterized in that described absorbing liquid vortex-flow and defrosting liquid trap (13) and dilute slurry vortex-flow and defrosting liquid trap (15) are vortex-flow and defrosting liquid trap, described vortex-flow and defrosting liquid trap comprises vortex-flow and defrosting liquid trap base plate (41), multiplely rises inflator (37), eddy flow (34), sieve plate (35), demist baffle plate (36), falls liquid stay pipe (40), catch tray (39), liquid-leaking nozzle (38) and liquid trap leakage fluid dram (42); Described vortex-flow and defrosting liquid trap base plate (41) is provided with liquid trap leakage fluid dram (42) for connecting absorbing liquid return duct (26) or dilute slurry return duct (28); Described inflator (37) bottom that rises is fixed on vortex-flow and defrosting liquid trap base plate (41), and adjacent two row rise inflator (37) being staggered in corresponding room; Described inflator (37) inside that rises is provided with eddy flow (34), described eddy flow (34) is fixed on through described sieve plate (35) and rises on inflator (37) inwall, described inflator (37) top that rises is provided with annular demist baffle plate (36), be evenly distributed with and fall liquid stay pipe (40) for supporting catch tray (39) rising inflator (37) top, described catch tray (39) center is provided with liquid-leaking nozzle (38).

8. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 7, it is characterized in that described sieve plate (35) comprises annular bottom plate and cylindric riser, the cylindric lower end of riser is fixedly connected with one end of annular bottom plate, the other end of base plate is fixed on and rises on inflator (37) inwall, the upper end of riser is used for fixing eddy flow (34), and described base plate is evenly provided with aperture.

9. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, is characterized in that described mist eliminator flushing spraying layer (19) is connected with technique water pipe (31); Described demister (18) is deflection plate demister or ridge type demister.

10. the classification Absorption Desulfurization device of ammonia ammonium sulphate process according to claim 1, it is characterized in that being provided with washing section packing layer (16) in described fume desulfurating absorption tower (1), described washing section packing layer (16) is arranged between dilute slurry vortex-flow and defrosting liquid trap (15) and dilute slurry spraying layer (17).