CN204933240U - Double tower Two-way Cycle Wet Limestone Desulfurization treatment system - Google Patents

Abstract

The utility model relates to the field of flue gas treatment and discloses a limestone wet desulfurization treatment system with two towers and two circulations. In the utility model, the first flue gas pipeline is connected to the flue gas inlet of the absorption tower A, the flue gas outlet of the absorption tower A is connected to the flue gas inlet of the absorption tower B through the second flue gas pipeline, and the flue gas outlet of the absorption tower B is connected to the discharge flue. The upper part of the interior is provided with a demister and a spray layer in sequence from top to bottom, and the lower part is provided with a slurry tank. The slurry storage tank is connected to the slurry inlet of the absorption tower through a slurry pump, and the oxidation fan is connected to the jet pipe of the absorption tower through an air pipe. The slurry outlet is connected to the spray pipe of the spray layer through the slurry circulation pump, the first gypsum outlet is connected to the liquid inlet of the gypsum cyclone through the pipeline, and the sedimentation outlet of the gypsum cyclone is connected to the vacuum belt dehydrator through the pipeline. The second gypsum outlet communicates with the bottom of the A absorption tower through a forced circulation pump. The utility model has high desulfurization efficiency, flexible structure control, wide application range and high cost performance.

Description

Twin-tower and double-circulation limestone wet desulfurization treatment system

technical field

The utility model relates to the field of flue gas treatment, in particular to a limestone wet desulfurization treatment system with double towers and double cycles.

Background technique

The existing flue gas desulfurization process is roughly divided into dry desulfurization and wet desulfurization. Due to the low efficiency of dry desulfurization, complicated operation process and difficulty in product utilization, wet desulfurization is more widely used. The flue gas desulfurization device of the existing thermal power plant generally adopts the working method of the first-stage absorption tower. The flue gas directly enters the absorption tower and reacts with the limestone slurry sprayed out of the tower. SO ₂ , SO ₃ and HCL in the flue gas _HF is absorbed, and the oxidation and neutralization reaction of the SO2 absorption product is completed in the oxidation zone at the bottom of the absorption tower and finally forms a gypsum by-product. Since the flue gas is continuously generated, the reaction only occurs when the flue gas is in contact with the limestone slurry , in the prior art, multiple spray layers are mostly set in the absorption tower to increase the contact probability and reaction effect between the flue gas and the limestone slurry, but for the flue gas with high concentration and fast flow rate, it is still impossible to effectively improve the efficiency of the equipment. For desulfurization efficiency, it is often necessary to add other auxiliary equipment, which increases the operation and maintenance costs, expands the occupied area, and increases the difficulty of operation. At the same time, the desulfurization efficiency is limited to a certain extent, and it is difficult to reach more than 90-95%. Therefore, it is particularly important to design a desulfurization device with simple structure, easy operation and high desulfurization efficiency.

Utility model content

The technical problem to be solved by the utility model is to provide a limestone wet desulfurization treatment system with two towers and two cycles with simple structure, easy operation and high desulfurization efficiency.

In order to solve the above technical problems, the utility model adopts the following technical solutions:

The utility model double-tower double-circulation limestone wet desulfurization treatment system includes a slurry storage tank, a first oxidation fan, a second oxidation fan, A absorption tower, B absorption tower, gypsum cyclone and a vacuum belt dehydrator, the first smoke The gas pipeline is connected to the flue gas inlet of absorption tower A, the flue gas outlet of absorption tower A is connected to the flue gas inlet of absorption tower B through the second flue gas pipeline, and the flue gas outlet of absorption tower B is directly connected to the exhaust flue;

Described A absorption tower comprises the first jet pipe, the first spray layer, the first mist eliminator, the first slurry inlet, the first slurry outlet, the first slurry circulation pump, the first gypsum outlet and the first filtering device, so The upper part of the A absorption tower is provided with the first demister and the first spray layer in sequence from top to bottom, and the lower part is provided with the first slurry tank, and the slurry storage tank is connected with the first slurry inlet of the A absorption tower through the slurry pump. The first oxidation fan is connected to the first jet pipe of the A absorption tower through the air pipe, the first slurry outlet is connected to the spray pipe of the first spray layer through the first slurry circulation pump, and the first filter is fixed inside the first slurry outlet. device, the first gypsum outlet communicates with the liquid inlet of the gypsum cyclone through the pipeline, and the sedimentation outlet of the gypsum cyclone communicates with the vacuum belt dehydrator through the pipeline;

The B absorption tower includes a second gas injection pipe, a second spray layer, a second demister, a second slurry inlet, a second slurry outlet, a second slurry circulation pump, a second gypsum outlet, a second filtering device and a forced Circulation pump, the upper part of the B absorption tower is provided with a second demister and a second spray layer in turn from top to bottom, and the lower part is provided with a second slurry pool, and the slurry storage tank is connected with the second slurry tank of the B absorption tower through the slurry pump. The slurry inlet is connected, the second oxidation blower is connected with the second spray pipe of the B absorption tower, the second slurry outlet is connected with the spray pipe of the second spray layer through the second slurry circulation pump, and the second slurry outlet is fixed inside the second slurry outlet. Filtration device, the second gypsum outlet communicates with the bottom of the A absorption tower through a forced circulation pump.

The utility model double-tower double-circulation limestone wet desulfurization treatment system, further, the first air injection pipe and the second air injection pipe are distributed in a pipe network, and a plurality of Vent.

In the utility model of the limestone wet desulfurization treatment system with double towers and double cycles, further, the first spray layer includes 4 layers of spray nets, and the second spray layer includes 3 layers of spray nets.

In the utility model of the limestone wet desulfurization treatment system with double towers and double cycles, further, the first demister is a single-layer ridge-type demist baffle, and the second demister is a double-layer diamond-shaped demist baffle.

The utility model double-tower double-circulation limestone wet desulfurization treatment system, further, the first and second filter devices are respectively a first filter cover and a second filter cover, and the first and second filter covers are evenly distributed There are a plurality of through holes with a diameter of 10-20mm, and the first filter cover and the second filter cover are respectively fixed in a detachable structure.

In the utility model, the limestone wet desulfurization treatment system with double towers and double cycles, further, the first filter cover and the second filter cover are made of 1.4529 alloy steel.

The utility model double-tower double-circulation limestone wet desulfurization treatment system further includes a first stirring device and a second stirring device, the first stirring device communicates with the lower part of the A absorption tower through a pipeline, and the second stirring device The device communicates with the lower part of the B absorption tower through pipelines.

In the utility model, the limestone wet desulfurization treatment system with double towers and double cycles, further, the first and second stirring devices are pulse suspension pumps or side stirrers.

Compared with the prior art, the utility model twin-tower double-circulation limestone wet desulfurization treatment system has the following beneficial effects:

The utility model adopts two-stage absorption towers to be used in series, and the sulfide in the flue gas is absorbed and neutralized by the desulfurizer CaCO ₃ slurry, and oxidized with air, and finally crystallized to generate gypsum CaSO ₄ ·2H ₂ O as a by-product, and the flue gas The gas is continuously washed by CaCO ₃ slurry twice, and the two times of sulfide removal efficiency can be superimposed, which can be as high as 99.9%, which effectively improves the desulfurization efficiency, and realizes the purpose of reducing sulfide emissions and purifying the air.

The air injection pipe in the absorption tower is set in a pipe network type, and multiple exhaust holes are evenly arranged on the air injection pipe. Compared with the general spray gun, the air introduced by the oxidation fan enters the slurry pool more evenly, so that the slurry can fully contact with oxygen , the oxidation reaction is more thorough and rapid, which not only reduces the standing time of the feed liquid in the slurry tank, improves the oxidation efficiency of the feed liquid, effectively saves resources and energy, but also improves the quality of by-products. The obtained gypsum by-products The free radical moisture is lower than 10% (weight percentage), the CaSO ₄ ·2H ₂ O content is higher than 90%, and the ^Cl- content dissolved in the gypsum is lower than 0.01% (weight percentage, taking gypsum without free moisture as a benchmark), The F ^- content dissolved in the gypsum is lower than 0.01% (percentage by weight, based on gypsum without free moisture).

Because the composition of the feed liquid in the slurry tank of the absorption tower is complex and the particle sizes are different, a filter cover is fixedly installed at the slurry outlet with a detachable structure, and a plurality of through holes are uniformly arranged on the filter cover, and the hole diameter is 10-20mm. Filter out the impurities with large particle size in the feed liquid to prevent the blockage of the slurry circulation pump, effectively guarantee the safety and continuous operation of the system, if necessary, the filter cover can be replaced, and can be reused after washing, economical, convenient, and does not affect The continuous operation of the system reduces the maintenance and operation costs of the equipment.

The spray layer and demister in the two absorption towers are set differently in terms of structure and quantity. The A absorption tower is equipped with 4 layers of spray layers and 1 layer of roof-type demist baffle, and the flue gas desulfurization rate can reach more than 95%. Nozzle coverage is as high as 200% or more; 3 layers of spray layers and 2 layers of diamond-shaped defogging baffles are set in the B absorption tower, because the sulfur content in the flue gas after the first-level washing is greatly reduced, so the number of spray layers is reduced , saving costs, because the flue gas after secondary washing and purification is directly discharged into the atmosphere, so the shape of the demisting baffle is changed, the demisting efficiency is improved, and the final exhausted flue gas meets the emission standard. The two absorption towers are set independently, and the circulation process in each absorption tower is also independently controlled, which avoids mutual constraints between the structure settings in the tower and parameter control, and is easy to optimize and quickly adjust, and can quickly adapt to changes in coal types and loads. Make the reaction and desulfurization process more in line with the actual flue gas conditions, make the reaction process more optimized and changeable, reliable equipment, high cost performance, strong adaptability, and wide application range.

The following is a further description of the twin-tower and double-circulation limestone wet desulfurization treatment system of the present invention in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is the structural representation of the utility model twin-tower double-circulation limestone wet desulfurization treatment system;

Fig. 2 is a top view of the first jet pipe.

detailed description

As shown in Figure 1, the utility model double-tower double-circulation limestone wet desulfurization treatment system includes a slurry storage tank 1, a first oxidation fan 41, a second oxidation fan 42, A absorption tower 2, B absorption tower 3, gypsum cyclone 7 and vacuum belt dehydrator 8, the first flue gas pipe 61 is connected to the flue gas inlet 21 of the A absorption tower, and the flue gas outlet 22 of the A absorption tower is communicated with the flue gas inlet 31 of the B absorption tower through the second flue gas pipe 62 , The flue gas outlet 32 of the B absorption tower is directly connected to the discharge flue 63 .

A absorption tower 2 comprises the first jet pipe 23, the first spray layer 24, the first demister 25, the first slurry inlet 281, the first slurry outlet 282, the first slurry circulation pump 261, the first filtering device 262, The first gypsum outlet 29, the first stirring device 51 and the return water inlet 291, the upper part of the absorption tower A is provided with the first demister 25 and the first spray layer 24 in sequence from top to bottom, and the lower part is provided with the first slurry pool 27. The first demister 25 is a single-layer ridge-type demister baffle, the first spray layer 24 includes 4 layers of spray nets, and the slurry storage tank 1 communicates with the first slurry inlet 281 of the A absorption tower through the slurry pump 11 , the first oxidation fan 41 is connected with the first jet pipe 23 of the A absorption tower through the air pipe 64. The exhaust hole 231, the first slurry outlet 282 communicates with the spray pipe of the first spray layer 24 through the first slurry circulation pump 261, and the first filter device 262 is fixed on the inside of the first slurry outlet 282 with a detachable structure. The filtering device 262 is a first filter cover, and a plurality of through holes are distributed on the first filter cover, and the aperture is 15mm. The liquid inlet of the gypsum cyclone 7 is connected to the liquid inlet, the precipitation outlet of the gypsum cyclone 7 is connected to the vacuum belt dehydrator 8 through a pipeline, the upper liquid outlet of the gypsum cyclone 7 is connected to the return water inlet 291 of the A absorption tower through a pipeline, and the first stirring device 51 communicates with the bottom of A absorption tower 2 through pipelines, and the first stirring device 51 can be selected pulse suspension pump, shown in Fig. .

B absorption tower 3 comprises the second air injection pipe 33, the second spray layer 34, the second demister 35, the second slurry inlet 381, the second slurry outlet 382, the second slurry circulation pump 361, the second filtering device 362, The second gypsum outlet 39, the second stirring device 52 and the forced circulation pump 65, the upper part of the B absorption tower is provided with the second demister 35 and the second spray layer 34 in sequence from top to bottom, and the lower part is provided with the second slurry pool 37. The second demister 35 is a double-layer rhombic demister baffle, the second spray layer 34 includes three layers of spray nets, and the slurry storage tank 1 communicates with the second slurry inlet 381 of the B absorption tower through the slurry pump 11. The second oxidizing blower 42 is connected with the second air injection pipe 33 of the B absorption tower. The second air injection pipe 33 is distributed in a pipe network and has the same structure as the first air injection pipe 23. The second air injection pipe 33 is evenly provided with a plurality of exhaust gas outlets. hole, the second slurry outlet 382 communicates with the spray pipe of the second spray layer 34 through the second slurry circulation pump 361, and the second filter device 362 is fixed with a detachable structure inside the second slurry outlet 382, and the second filter device 362 It is the second filter cover, with a plurality of through holes distributed on the second filter cover, the aperture is 15mm, the second filter cover is made of 1.4529 alloy steel material, the second gypsum outlet 39 communicates with the bottom of the A absorption tower through the forced circulation pump 65 , the second stirring device 52 communicates with the bottom of the B absorption tower 3 through the pipeline, the second stirring device 52 communicates with the bottom of the B absorption tower 3 through the pipeline, and the second stirring device 52 can select a pulse suspension pump, as shown in Fig. 1 For the pulse suspension pump, other agitating devices commonly used in this field can also be selected, such as side agitators.

The specific working process of the utility model double-tower double-circulation limestone wet desulfurization treatment system is as follows:

_The slurry pump 11 pumps the fresh CaCO3 slurry into the slurry pool 27 of the A absorption tower 2, and the slurry passes through the first filter cover to filter out impurities with larger particles and then is sent to the first spray layer 24 through the first slurry circulation pump 261. In the spray pipe, the flue gas to be treated enters the A absorption tower 2 through the first flue gas pipe 61, and the flue gas directly contacts with the CaCO ₃ slurry sprayed down by the first spray layer 24, and the sulfide in the flue gas is absorbed by the CaCO ₃ Slurry absorption, most of the generated H ₂ SO ₃ and H ₂ SO ₄ fall into the first slurry pool 27, mix evenly under the stirring of the first stirring device 51, and neutralize with CaCO ₃ to generate CaSO ₃ and CaSO ₄ ; the first oxidation blower 41 blows air into the first slurry tank 27 to promote the oxidation reaction to generate most of CaSO ₄ and crystallize to form CaSO ₄ 2H ₂ O; the mixed slurry is filtered through the first filter cover The first slurry circulation pump 261 is pumped into the spray layer again to form a continuous slurry circulation, which circulates in the A absorption tower 2 for 4-5 times, and the reaction time is controlled at about 5 minutes; in the A absorption tower, more than 95% of the flue gas sulfides can be removed.

After one wash, the flue gas is sent to the B absorption tower 3 through the second flue gas pipeline 62 after being removed by the first demister 25, and the fresh CaCO3 slurry is pumped into the B absorption tower 3 by the slurry pump 11 , the slurry is sent to the spray pipe of the second spray layer 34 by the second slurry circulation pump 361 after filtering out impurities with larger particles through the second filter cover, contacts with the flue gas after the first washing and falls into the second slurry In the pool 37, the mixed slurry is continuously circulated and sprayed for 4-5 times, and the second oxidation fan 42 blows air into the second slurry pool 37, and is mixed evenly under the stirring of the second stirring device 52 to complete the absorption and neutralization of sulfides. and, oxidation and crystallization processes. The amount of gypsum CaSO ₄ ·2H ₂ O formed in B absorption tower 3 is very small, it is sent into A absorption tower 2 through forced circulation pump 65, mixed with CaSO ₄ ·2H ₂ O generated in A absorption tower 2, together Send it into the gypsum cyclone 7 and dry it through the vacuum belt dehydrator 8 to obtain the gypsum by-product. After the secondary washing, the flue gas passes through the second demister 35 to remove large liquid droplets, and then is directly discharged into the atmosphere through the discharge flue 63, and the desulfurization rate of the flue gas after the secondary washing can be as high as 99.9%.

The embodiments described above are only descriptions of preferred implementations of the present utility model, and are not intended to limit the scope of the present utility model. Various modifications and improvements made should fall within the scope of protection determined by the claims of the utility model.

Claims (8)

1. double tower Two-way Cycle Wet Limestone Desulfurization treatment system, comprise serum storage tank, the first oxidation fan, the second oxidation fan, A absorption tower, B absorption tower, gypsum cyclone and vacuum belt dewaterer, first flue connects the gas approach on A absorption tower, the exhanst gas outlet on A absorption tower is communicated with the gas approach on B absorption tower by the second flue, the exhanst gas outlet on B absorption tower directly connects discharge flue, it is characterized in that:

Described A absorption tower comprises the first air jet pipe, first spraying layer, first demister, first injection point, first serum outlet, first slurry circulating pump, first gypsum outlet and the first filter, the inner epimere in described A absorption tower is disposed with the first demister and the first spraying layer from top to bottom, hypomere is provided with the first slurry pool, serum storage tank is communicated with first injection point on A absorption tower by slush pump, first oxidation fan is connected with first air jet pipe on A absorption tower by air duct, first serum outlet is communicated with the shower of the first spraying layer by the first slurry circulating pump, the first filter is fixed with inside first serum outlet, first gypsum outlet is communicated with by the inlet of pipeline with gypsum cyclone, the precipitation outlet of gypsum cyclone is communicated with vacuum belt dewaterer by pipeline,

Described B absorption tower comprises the second air jet pipe, second spraying layer, second demister, second injection point, second serum outlet, second slurry circulating pump, second gypsum outlet, second filter and forced circulation pump, the inner epimere in described B absorption tower is disposed with the second demister and the second spraying layer from top to bottom, hypomere is provided with the second slurry pool, serum storage tank is communicated with second injection point on B absorption tower by slush pump, second oxidation fan is connected with second air jet pipe on B absorption tower, second serum outlet is communicated with the shower of the second spraying layer by the second slurry circulating pump, the second filter is fixed with inside second serum outlet, second gypsum outlet is communicated with bottom A absorption tower by forced circulation pump.

2. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 1, is characterized in that: described first air jet pipe and the second air jet pipe, all in pipe net distribution, the first air jet pipe and the second air jet pipe evenly offer multiple steam vent.

3. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 1, it is characterized in that: described first spraying layer comprises 4 layers of spraying net, the second spraying layer comprises 3 layers of spraying net.

4. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 1, is characterized in that: described first demister is individual layer ridge-roof type demist baffle plate, and the second demister is two-tier rhombic demist baffle plate.

5. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 1, it is characterized in that: first, second filter described is respectively the first filter bowl and the second filter bowl, first, second filter bowl described is evenly distributed with multiple through hole, aperture is 10-20mm, and the first filter bowl and the second filter bowl are fixed with demountable structure respectively.

6. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 5, is characterized in that: described first filter bowl and the second filter bowl adopt 1.4529 alloy steel materials to make.

7. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 1, it is characterized in that: also comprise the first agitating device and the second agitating device, described first agitating device is communicated with by the bottom of pipeline with A absorption tower, and described second agitating device is communicated with by the bottom of pipeline with B absorption tower.

8. double tower Two-way Cycle Wet Limestone Desulfurization treatment system according to claim 7, is characterized in that: first, second agitating device described is pulse suspension pump or side agitator.