CN103736381A - Dust removal device and dust removal method for sintering flue gas by shunted and graded desulfurization - Google Patents

Abstract

The present invention relates to a sintering flue gas diversion graded desulfurization and dust removal device. The device includes a bellows group of a sintering machine, a desulfurization tower and a blast furnace gas release tower. The bellows group of the sintering machine is connected with the flue gas inlet of the desulfurization tower. The flue gas outlet of the desulfurization tower is connected with the inlet of the blast furnace gas release tower, an outlet is arranged on the top of the blast furnace gas release tower, and a burner is arranged outside the blast furnace gas release tower at the outlet. The device of the invention can not only treat the whole flue gas, make the emission of sulfur dioxide meet the standard, eliminate the pollution of dioxin in the flue gas to the environment as much as possible, but also divide the high-sulfur flue gas and low-sulfur flue gas into the same desulfurization tower for desulfurization Staged desulfurization treatment, compared with the traditional method of mixing high and low sulfur flue gas first and then treating the whole flue gas, the size of the desulfurization tower is smaller and the cost is lower, which reduces the investment and operation cost of the desulfurization tower.

Description

A sintering flue gas split flow classification desulfurization and dust removal device and dust removal method

technical field

The invention belongs to the field of iron and steel metallurgy sintering flue gas purification, in particular to a split-flow and graded desulfurization and dust removal device and a dust removal method for iron and steel metallurgy sintering flue gas.

Background technique

During the "Twelfth Five-Year Plan" period, my country has clearly required that the iron and steel industry achieve full desulfurization. Sintering flue gas desulfurization has always been the focus of environmental governance in the iron and steel industry. The composition of sintering flue gas in China's iron and steel industry is complex and fluctuates greatly. It has the following characteristics: First, the amount of flue gas is large ^. The second is that the concentration of sulfur dioxide varies greatly, ranging from 400 to 5000mg/ ^Nm3 ; the third is that the temperature changes greatly, generally from 80°C to 180°C; the fourth is that the flow rate changes greatly, and the range of change is as high as more than 40%; Large and unstable, generally 10-13%; sixth, high oxygen content, generally 15-18%; nitrogen oxides, etc. These characteristics have increased the difficulty of sulfur dioxide treatment in steel sintering flue gas to a certain extent.

In the sintering process of iron and steel production, dioxins are mainly generated through the path of "de novo synthesis", that is, under the temperature range of 250-450 degrees and an oxidizing atmosphere, macromolecular carbon and organic chlorine are generated under the catalysis of heavy metal ions such as copper and iron. .

Since the Ministry of Industry and Information Technology issued the "Implementation Plan for Sintering Flue Gas Desulfurization in the Iron and Steel Industry" in July 2009, policies and regulations on iron and steel desulfurization have become increasingly stringent. According to the latest "Steel Sintering and Pelletizing Industry Air Pollutant Emission Standard" (GB28662-2012) that came into effect on October 1, 2012, the SO ₂ emission limits for existing enterprises and new enterprises are 600mg/m ³ and 200mg respectively /m ³ , the emission limits of dioxins are 1.0ng-TEQ/m ³ and 0.5ng-TEQ/m ³ respectively.

At present, the sintering flue gas desulfurization technology in the iron and steel industry can be basically divided into three categories according to the form of desulfurization products: wet desulfurization technology, semi-dry desulfurization technology, and dry desulfurization technology. According to the process classification, there are currently more than ten technologies for sintering flue gas desulfurization in my country, such as circulating fluidized bed method, limestone-gypsum method, SDA rotary spray method, ammonia method, activated carbon adsorption method, magnesium oxide method, dense phase dry tower method, and MEROS method. , has accumulated a certain amount of application experience.

At present, Chinese scientific and technical personnel have carried out some research on sintering flue gas desulfurization and dust removal technology, such as the invention patent with the announcement number CN101306311A, because it is full flue gas desulfurization, so the cost is high and the site layout is tense; for example, the patent with the announcement number CN201302374Y , although the selective desulfurization of the sintering flue gas has greatly reduced the equipment and operating costs, but if the desulfurization part is not desulfurized due to changes in the mine, the sulfur content will increase and the sulfur emission will exceed the standard; such as the patent with the announcement number CN102003886B, also The flue gas from different parts of the bellows is treated differently. In addition to the full treatment of high-sulfur flue gas, the flue gas volume of low-sulfur flue gas is adjusted through the flue gas diversion device, which further improves the reliability of the flue gas emission in the whole system. However, some low-sulfur flue gas is still discharged directly without treatment, and it is difficult to control the proportion of low-sulfur flue gas treatment.

According to the formation mechanism and emission characteristics of dioxins in the process, there are mainly the following methods to control their formation and emission: (1) Adding inhibitors to improve the conditions of the sinter layer and prevent the formation of dioxins in the synthesis and other prerequisite compound. Such as spraying ammonia or using urea to control the catalytic effect of copper and other metals on dioxin in the smoke. (2) Flue gas circulation, so that the generated flue gas re-enters the sintering layer, reducing the amount of dioxins and other pollutants; (3) Rapid cooling, so that the flue gas is rapidly cooled from the temperature range of 250 to 450 degrees to below 200 degrees; (4) Activated carbon/activated lignite adsorption combined with bag filter has the disadvantage of increasing the dust load, and it is difficult to regenerate and treat activated carbon after adsorption; (5) Catalyst catalytic reduction, oxidizing dioxin at low temperature to generate CO ₂ , hydrated HCl and other inorganic substances The disadvantage is that the catalyst is expensive and prone to poisoning and clogging.

Through searching, the following patent publication related to the patent application of the present invention was found:

Sintering flue gas wet desulfurization and dust removal process (CN101168118), provides a sintering flue gas wet desulfurization and dust removal process. After the sintering flue gas is pressurized, it is cooled and defluorinated first, so that the HF in the flue gas is captured by the lye and the temperature of the flue gas is lowered to below 80°C; then the flue gas enters the high-efficiency desulfurization absorption tower, and is circulated through the jet pipe in the tower. The function of the flow device makes the flue gas swirl into the slurry pool at high speed, the flue gas is broken in the slurry and fully mixed with the slurry to complete the desulfurization and dust removal process; the net flue gas after demisting is reheated by the sintering waste heat steam from the Chimney exhaust. The desulfurization and dust removal process can realize a desulfurization efficiency of over 95% and a dust removal efficiency of 99%. The setting of the cooling defluorinator ensures the thermal safety of the absorption tower and reduces the degree of corrosion inside the tower. The high-efficiency desulfurization absorption tower has no slurry circulation pump, and there are no moving parts in the tower, and the gas-liquid contact effect is good. The reheating method using sintering waste heat steam saves the conventional GGH, improves the stability of the system operation and reduces the system cost.

By comparison, the patent application of the present invention is substantially different from the above-mentioned patent publications.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a sintering fume that can not only treat the whole flue gas in stages, appropriately reduce investment and operating costs, but also make the emission of sulfur dioxide reach the standard and reduce the emission of dioxins. The gas splitting classification desulfurization and dust removal device and the dust removal method are simple, easy to operate, low in cost and good in dust removal effect.

The technical solution adopted by the present invention to solve its technical problems is:

A sintering flue gas split-flow graded desulfurization and dust removal device, the device includes a sintering machine wind box group, a desulfurization tower and a blast furnace gas release tower, the sintering machine wind box group is connected to the flue gas inlet of the desulfurization tower, and the desulfurization tower The flue gas outlet is connected together with the entrance of the blast furnace gas release tower, an outlet is arranged on the top of the blast furnace gas release tower, and a burner is arranged outside the blast furnace gas release tower at the exit;

In the bellows group of the sintering machine, the head end of the bellows, the middle of the bellows and the end of the bellows are arranged in sequence;

The tower below the flue gas outlet of the desulfurization tower is provided with a liquid storage section, a first spray section, a swirl treatment section, a second spray section, and a demisting section from bottom to top, and is arranged outside the desulfurization tower. A circulation pump, the output end of the circulation pump is respectively connected to the first spray section and the second spray section through pipelines, and the input end of the circulation pump is connected to the liquid storage section and installed together;

On one side of the tower body between the liquid storage section and the first spray section, the first flue gas inlet is communicated with, and the tower of the desulfurization tower between the swirl treatment section and the second spray section A second flue gas inlet is communicated with and arranged on the side wall of the body;

The first flue gas inlet is sequentially connected with the booster fan, the first chlorine removal pre-washing device, the first induced draft fan, the first bag filter and the output end of the first quencher arranged outside the desulfurization tower, The input end of the first quencher is connected to the middle part of the air box; the second flue gas inlet is sequentially connected to the second dechlorination pre-washing device, the second induced draft fan, the second bag filter and the second dust collector installed outside the desulfurization tower. The output ends of the two quick coolers are connected together, and the input ends of the second quick cooler are connected together with the head end of the wind box and the end of the wind box respectively.

Moreover, a plurality of spraying sections are arranged between the second spraying section and the demisting section.

Moreover, the cyclone processing section includes an upper sealing plate, a lower sealing plate, a cyclone cylinder and a cyclone, and several vertical, upper and lower An open, hollow swirl tube, a swirler is coaxially installed at the bottom of the swirl tube, the swirl device includes a swirl vane shaft and a swirl vane, and the swirl vanes are arranged in a ring around the swirl vane shaft , and obliquely installed on the swirl vane shaft, the swirl vane shaft is coaxially installed with the swirl cylinder, and the outer edges of the upper sealing plate and the lower sealing plate are coaxially sealed and installed on the inner wall of the tower.

Moreover, the swirl blade is a propeller-type inclined blade structure, and its inclination angle is 30-60 degrees from the axial direction.

Moreover, the number of the swirl blades is 3-12, and the swirl blades are in the shape of a plane or a curved surface.

Moreover, the number of the swirl cylinders is 10-100, and the height of the swirl cylinders is 300mm-1000mm.

The dedusting method utilizing the above-mentioned sintering flue gas split flow graded desulfurization and dedusting device comprises the following steps:

(1) The sintering flue gas enters the bellows group of the sintering machine, and the high-sulfur flue gas in the middle of the bellows of the bellows group passes through the first quencher, the first bag filter, the first induced draft fan, and After the first dechlorination pre-washing device and booster fan, enter the desulfurization tower from the first flue gas inlet of the desulfurization tower;

(2) The low-sulfur flue gas from the head end of the wind box and the end of the wind box of the wind box group passes through the second quencher, the second bag filter, the second induced draft fan and the second dechlorination pre-washing device arranged between the wind box group and the desulfurization tower in sequence After that, enter the desulfurization tower from the second flue gas inlet of the desulfurization tower;

(3) The circulation pump installed outside the desulfurization tower pumps the spray liquid in the liquid storage section set at the bottom of the desulfurization tower, and then sprays the spray liquid from the first spray section and the second spray section, and the high-sulfur fume After the gas enters the desulfurization tower through the first flue gas inlet, the desulfurizer sprayed in the first spray section cools down and partially desulfurizes, and then enters the cyclone treatment section, where it rotates upward at a high speed under the action of the cyclone, and is connected with the second spray section. The desulfurizer sprayed by the shower section is rotary cut and mixed at high speed to complete the main desulfurization reaction; in the space between the second spray section and the swirl treatment section, the low-sulfur flue gas enters the desulfurization tower through the second flue gas inlet , mixed with the high-sulfur flue gas flowing upward after passing through the cyclone treatment section, and contacting and reacting with the desulfurizer sprayed under the second spraying section;

(4) The mixed flue gas of purified high-sulfur flue gas and low-sulfur flue gas enters the demister to remove the liquid droplets in the flue gas, and the flue gas after demisting is introduced into the blast furnace gas release tower through the pipe from the flue gas outlet of the desulfurization tower Inside, after being mixed with blast furnace gas in the blast furnace gas release tower, it is released into the atmosphere after being ignited by the burner at the top outlet of the blast furnace gas release tower.

Moreover, in the step (3), 1 to more spray sections are set above the second spray section.

Moreover, the outlet temperature of the first quencher and the second quencher is controlled at 150-180°C.

Moreover, the outlet temperature of the first dechlorination pre-washing device and the second dechlorination pre-washing device is controlled at 80-90°C.

Advantage and positive effect of the present invention are:

1. The device of the present invention can not only treat the whole flue gas, make the emission of sulfur dioxide meet the standard, eliminate the pollution of dioxin in the flue gas to the environment as much as possible, but also divide the high-sulfur flue gas and low-sulfur flue gas into the same desulfurization Compared with the traditional way of mixing high and low sulfur flue gas first and then treating the whole flue gas, the desulfurization tower is smaller in size and lower in cost, which reduces the investment and operation cost of the desulfurization tower.

2. The device of the present invention is equipped with a quencher, which will rapidly reduce the temperature of the flue gas from 250 to 450 degrees to below 200 degrees, and miss the best generation temperature of dioxins as much as possible, further reducing the probability of dioxins in the flue gas. At the same time, it is beneficial for dioxin to be adsorbed on the surface of the dust in solid form, and it is mainly adsorbed on fine particles.

3. After the quencher of the device of the present invention, a bag filter with higher dust removal efficiency than wet dust removal and electrostatic dust removal is selected to avoid the phenomenon that dioxins are easily adsorbed on fine particles in the flue gas when the temperature is below 200 degrees occurs, the dust removal efficiency can reach 85% to 90% or higher, which improves the dioxin removal efficiency and can also remove heavy metals such as copper and iron that can catalyze the formation of dioxins.

4. The device of the present invention is equipped with a chlorine removal pre-washing device after dust removal to remove chlorine ions in the flue gas to the greatest extent, reduce the generation conditions of dioxins, and remove a large amount of other acid gases at the same time, reducing the corrosion of follow-up equipment such as desulfurization towers .

5. The flue gas outlet of the desulfurization tower of the device of the present invention is connected to the blast furnace gas release tower through a pipeline. After desulfurization, the flue gas and blast furnace gas are mixed and burned, and can be easily discharged above the dew point temperature, which improves the diffusion of pollutants. The flue gas pre-treatment process removes chloride ions and heavy metals such as copper and iron, so that the regeneration of dioxins can be avoided as much as possible during combustion.

6. The dust removal method of the present invention is simple, easy to operate, low in cost and good in dust removal effect.

Description of drawings

Fig. 1 is the structural connection schematic diagram of the present invention;

Fig. 2 is the enlarged schematic view of the structure of the cyclone treatment section in Fig. 1;

FIG. 3 is a top view of FIG. 2 .

Detailed ways

Hereinafter, the present invention will be further described in detail by taking the embodiment of the accompanying drawings as an example. The following embodiments are only descriptive, not restrictive, and cannot limit the protection scope of the present invention.

A sintering flue gas diversion classification desulfurization and dust removal device, as shown in Figure 1, the device includes a sintering machine bellows group (not labeled in the figure), a desulfurization tower 9 and a blast furnace gas release tower 11; the sintering machine bellows group It is connected with the flue gas inlet of the desulfurization tower, and the flue gas outlet 10 of the desulfurization tower is connected with the inlet of the blast furnace gas release tower. An outlet is arranged on the top of the blast furnace gas release tower, and the blast furnace gas at the outlet is released. A burner 12 is arranged outside the tower.

In the bellows group of the sintering machine, a bellows head 1 , a bellows middle 2 and a bellows end 3 are arranged in sequence.

The top of the tower body of the desulfurization tower is provided with a flue gas outlet, and a liquid storage section 17, a first spraying section 16, a swirl treatment section 15, a Two spraying sections 14 and demisting sections 13, a circulation pump 18 is arranged outside the desulfurization tower, and the output end of the circulation pump is connected together with the first spraying section and the second spraying section respectively through pipelines, and the circulation The input end of the pump is connected with the liquid storage section and installed together;

In order to strengthen the desulfurization treatment of low-sulfur flue gas and also have a certain desulfurization effect on high-sulfur flue gas, multiple spraying sections can be set between the second spraying section and the demisting section.

The first flue gas inlet 19 is communicated on one side of the tower body between the liquid storage section and the first spray section, and the desulfurization tower between the swirl treatment section and the second spray section A second flue gas inlet 8 is connected to the side wall of the tower body;

The first flue gas inlet is sequentially connected with the output end of the booster fan 20, the first dechlorination pre-washing device 21, the first induced draft fan 22, the first bag filter 23 and the first quench cooler 24 arranged outside the desulfurization tower. connected together (the first flue gas inlet is connected to the output end of the booster fan, the input end of the booster fan is connected to the output end of the first dechlorination pre-washing device, the input end of the first dechlorination pre-washing device It is connected to the output end of the first induced draft fan, the input end of the first induced draft fan is connected to the output end of the first bag filter, and the input end of the first bag filter is connected to the output end of the first quencher), The input end of the first quencher is connected to the middle of the wind box;

The second flue gas inlet is sequentially connected with the second dechlorination prewashing device 7, the second induced draft fan 6, the second bag filter 5 and the output end of the second quench cooler 4 arranged outside the desulfurization tower ( The second flue gas inlet is connected to the output end of the second dechlorination prewashing device, the input end of the second dechlorination prewashing device is connected to the output end of the second induced draft fan, and the input end of the second induced draft fan is connected to the second The output end of the bag filter is connected, the input end of the second bag filter is connected to the output end of the second quencher), and the input end of the second quencher is connected to the head end of the bellows and the end of the bellows respectively;

As shown in Figures 2 and 3, the cyclone treatment section includes an upper sealing plate 25, a lower sealing plate 26, a swirl cylinder 29 and a cyclone, and the upper sealing plate and the lower sealing plate are evenly spaced along the Axial seals are provided with several vertical, upper and lower openings, and hollow swirl cylinders. A swirler is coaxially installed at the bottom of the swirl cylinder, and the swirler includes a swirl vane shaft 27 and a swirl vane 28 , the swirl blades are arranged in a ring around the swirl blade shaft, and are obliquely installed on the swirl blade shaft, and the swirl blade shaft is installed coaxially with the swirl cylinder. The swirl blade is a propeller-type inclined blade structure, and its inclination angle is 30-60 degrees to the axial direction. The number of the swirl blades can be determined according to the specific situation, generally 3 to 12 pieces, and 6 pieces are set in this embodiment Swirl vane: The swirl vane can take the shape of a plane or a curved surface, and this embodiment is a plane vane. The outer edges of the upper sealing plate and the lower sealing plate are coaxially sealed and installed on the inner wall of the tower. The upper sealing plate and the lower sealing plate can prevent the short circuit of the flue gas, and close the cross-section of the desulfurization tower body other than the cyclone. The sealing plate can be welded on the cyclone cylinder. The number of said swirl tubes can be 10-100. In this embodiment, 12 swirl tubes are arranged between the upper sealing plate and the lower sealing plate, arranged in an equidistant rectangular array, and the height of the swirl tubes is 300 mm. ~1000mm.

The dedusting method utilizing the above-mentioned sintering flue gas split flow graded desulfurization and dedusting device comprises the following steps:

(1) The sintering flue gas enters the bellows group of the sintering machine, and the high-sulfur flue gas in the middle of the bellows of the bellows group passes through the first quencher, the first bag filter, the first induced draft fan, and After the first dechlorination pre-washing device and booster fan, enter the desulfurization tower from the first flue gas inlet of the desulfurization tower;

The first dechlorination pre-washing device uses lye to pre-wash the sintering flue gas, which can basically remove HCl and HF;

(2) The low-sulfur flue gas from the head end of the wind box and the end of the wind box of the wind box group passes through the second quencher, the second bag filter, the second induced draft fan and the second dechlorination pre-washing device arranged between the wind box group and the desulfurization tower in sequence After that, enter the desulfurization tower from the second flue gas inlet of the desulfurization tower;

The second dechlorination pre-washing device uses lye to pre-wash the sintering flue gas, which can basically remove HCl and HF;

(3) The circulation pump installed outside the desulfurization tower pumps the spray liquid in the liquid storage section set at the bottom of the desulfurization tower, and then sprays the spray liquid from the first spray section and the second spray section, and the high-sulfur fume After the gas enters the desulfurization tower through the first flue gas inlet, the desulfurizer sprayed in the first spray section cools down and partially desulfurizes, and then enters the cyclone treatment section, where it rotates upward at a high speed under the action of the cyclone, and is connected with the second spray section. The desulfurizer sprayed by the shower section is rotary cut and mixed at high speed to complete the main desulfurization reaction; in the space between the second spray section and the swirl treatment section, the low-sulfur flue gas enters the desulfurization tower through the second flue gas inlet , mixed with the high-sulfur flue gas flowing upward after passing through the cyclone treatment section, and contacting and reacting with the desulfurizer sprayed under the second spraying section;

If necessary, a third spray section can be set above the second spray section to further strengthen the desulfurization treatment of low-sulfur flue gas, and also have a certain desulfurization effect on high-sulfur flue gas;

(4) The mixed flue gas of purified high-sulfur flue gas and low-sulfur flue gas enters the demister to remove the liquid droplets in the mixed flue gas, and the flue gas after demisting is introduced into the blast furnace gas from the flue gas outlet of the desulfurization tower through the pipeline to release In the tower, after the blast furnace gas is mixed with the blast furnace gas in the blast furnace gas release tower, it is released into the atmosphere after being ignited by the burner at the top outlet of the blast furnace gas release tower.

In order to further reduce the generation of dioxins in the flue gas, the dust removal method of the present invention will rapidly lower the temperature of the flue gas from 250 to 450°C to below 200°C. It is controlled at 150-180°C, and it is controlled at about 170°C in this embodiment. In view of the characteristics of high temperature and high humidity of the sintering flue gas, the outlet temperature of the first dechlorination pre-washing device and the second dechlorination pre-washing device is controlled at 80-90°C, and in this embodiment, it is controlled at 80°C to reduce the temperature of the flue gas Effect on desulfurization tower. After the purified flue gas is mixed with the blast furnace gas in the blast furnace gas release tower, it is burned by a burner to ensure that the temperature of the flue gas is greater than the dew point temperature during the release.

In order to remove dioxins as much as possible while desulfurizing, the dust removal method of the present invention takes the following measures before the flue gas enters the desulfurization tower: (1) In order to further reduce the formation of dioxins in the flue gas, the flue gas temperature Rapidly cool down from 250 to 450°C to below 200°C to miss the optimum formation temperature of dioxins as much as possible; (2) When dioxins are below 200°C, they are easily adsorbed on fine particles in the flue gas, so after the quencher Choose a bag filter with higher dust removal efficiency (compared to wet dust removal and electrostatic dust removal), the dust removal efficiency can reach 85% to 90% or higher, and the maximum possible removal of heavy metals, fine dust and dioxins; (3) to remove Chloride ions that lead to the generation of dioxin can be installed with a chlorine removal pre-washing device, and the flue gas can be pre-washed with lye, which can basically remove HCl and HF. (4) The purified flue gas treated by the desulfurization tower enters the blast furnace gas release tower and is mixed with the blast furnace gas for combustion. Because the dechlorination link and bag dust removal link before the desulfurization tower remove the chlorine ions necessary for the formation of dioxin and play a catalytic role Heavy metals such as copper and iron make it possible to avoid the regeneration of dioxins during combustion.

The working principle of the sintering flue gas split classification desulfurization and dust removal device of the present invention is as follows:

According to the characteristics of the sintering flue gas, generally the flue gas temperature of the wind box at the head _{end is low, and the SO 2 generated} is very little _; Usually, the exhaust system of large and medium-sized sintering units is configured according to two induced draft fans. The flue gas from the first and end air boxes is combined into one path, which is the so-called low-sulfur flue gas, and the flue gas from the middle bellows is combined into one path, which is the so-called high-sulfur flue gas. According to the actual measurement data of the flue gas of the sintering machine, the flue gas volume of high-sulfur and low-sulfur flue gas is not much different. The present invention adopts two kinds of process lines: a high-sulfur treatment process line and a low-sulfur treatment process line. Both high and low sulfur flue gas pass through the quench cooler, bag filter, induced draft fan and chlorine removal pre-washing device, and then the low sulfur flue gas directly enters the second flue gas inlet of the desulfurization tower, while the high sulfur flue gas is boosted by the booster fan Then enter the first flue gas inlet of the desulfurization tower. According to the difference of _SO2 concentration of the two streams of flue gas, high-sulfur flue gas and low-sulfur flue gas enter different flue gas inlets for graded treatment. Low-sulfur flue gas is treated with only one layer of spraying. Due to the high resistance of the cyclone treatment section, an additional booster fan is installed in front of the desulfurization tower in the high-sulfur treatment process line for pressurization. After the high-sulfur flue gas enters the desulfurization tower through the first flue gas inlet, the desulfurizer sprayed in the first spray section cools down and enters the cyclone treatment section after preliminary desulfurization. Under the action of the cyclone, a certain speed gas is formed. The upward swirling airflow holds the desulfurizer sprayed by the second spraying section and repeatedly rotary cuts to form a dynamic and stable gas-liquid suspension layer. The gas-liquid is continuously gathered, dispersed and mixed to complete the main desulfurization reaction; In the desulfurization tower between the spray section and the cyclone treatment section, the low-sulfur flue gas enters the desulfurization tower through the second flue gas inlet, mixes with the high-sulfur flue gas that flows upward after passing through the cyclone treatment section, and is mixed with the The desulfurizing agent sprayed in the second spraying section contacts and reacts in reverse; in general, the low-sulfur flue gas undergoes one-stage spray desulfurization treatment, while the high-sulfur flue gas undergoes two-stage spraying and one-stage cyclone enhanced desulfurization treatment. The purified mixed flue gas enters the demister to remove the liquid droplets in the flue gas, and is introduced from the flue gas outlet through the pipeline into the blast furnace gas release tower to mix with the blast furnace gas, and is released into the atmosphere after being ignited by the burner at the top outlet of the blast furnace gas release tower . This hierarchical full flue gas treatment method can not only ensure that all flue gas can meet the desulfurization index requirements, but also compared with the traditional method of mixing high and low sulfur flue gas first and then full flue gas treatment, the desulfurization tower is smaller in size and lower in cost.

Claims (10)

1. A sintering flue gas shunt classification desulfurization and dedusting device, said device comprises a bellows group of a sintering machine, a desulfurization tower and a blast furnace gas release tower, it is characterized in that: the bellows group of said sintering machine is connected to the flue gas inlet of the desulfurization tower Connected, the flue gas outlet of the desulfurization tower is connected with the inlet of the blast furnace gas release tower, an outlet is arranged on the top of the blast furnace gas release tower, and a burner is arranged outside the blast furnace gas release tower at the outlet; In the bellows group of the sintering machine, the head end of the bellows, the middle of the bellows and the end of the bellows are arranged in sequence; The tower below the flue gas outlet of the desulfurization tower is provided with a liquid storage section, a first spray section, a swirl treatment section, a second spray section, and a demisting section from bottom to top, and is arranged outside the desulfurization tower. A circulation pump, the output end of the circulation pump is connected to the first spray section and the second spray section respectively, and the input end of the circulation pump is connected to the liquid storage section and installed together; On one side of the tower body between the liquid storage section and the first spray section, the first flue gas inlet is communicated with, and the tower of the desulfurization tower between the swirl treatment section and the second spray section A second flue gas inlet is communicated with and arranged on the side wall of the body; The first flue gas inlet is sequentially connected with the booster fan, the first chlorine removal pre-washing device, the first induced draft fan, the first bag filter and the output end of the first quencher arranged outside the desulfurization tower, The input end of the first quencher is connected to the middle part of the air box; the second flue gas inlet is sequentially connected to the second dechlorination pre-washing device, the second induced draft fan, the second bag filter and the second dust collector installed outside the desulfurization tower. The output ends of the two quick coolers are connected together, and the input ends of the second quick cooler are connected together with the head end of the wind box and the end of the wind box respectively. 2. The sintering flue gas split-flow graded desulfurization and dust removal device according to claim 1, characterized in that a plurality of spraying sections are arranged between the second spraying section and the demisting section. 3. The sintering flue gas split-flow graded desulfurization and dust removal device according to claim 1, characterized in that: the cyclone treatment section includes an upper sealing plate, a lower sealing plate, a cyclone cylinder and a cyclone, and the upper sealing plate Several vertical, upper and lower openings, and hollow swirl tubes are arranged at uniform intervals along the axial direction between the lower sealing plate, and a swirler is coaxially installed at the bottom of the swirl tube, and the swirl device includes The swirl blade shaft and the swirl blade, the swirl blades are arranged in a ring around the swirl blade shaft, and are installed obliquely on the swirl blade shaft, the swirl blade shaft is installed coaxially with the swirl cylinder, the upper sealing plate and the lower The outer edge of the sealing plate is coaxially sealed on the inner wall of the tower. 4 . The sintering flue gas split-flow graded desulfurization and dust removal device according to claim 3 , characterized in that: the swirl blade is a propeller-type inclined blade structure, and its inclination angle is 30-60 degrees from the axial direction. 5. The sintering flue gas splitting and graded desulfurization and dust removal device according to claim 3 or 4, characterized in that: the number of swirl blades is 3-12, and the swirl blades are in the shape of a plane or a curved surface. 6 . The sintering flue gas split-flow graded desulfurization and dust removal device according to claim 3 or 4, characterized in that: the number of said swirl cylinders is 10-100, and the height of the swirl cylinders is 300mm-1000mm. 7. A dedusting method utilizing the sintering flue gas split classification desulfurization dedusting device as described in any one of claims 1 to 6, characterized in that: comprising the following steps: (1) The sintering flue gas enters the bellows group of the sintering machine, and the high-sulfur flue gas in the middle of the bellows of the bellows group passes through the first quencher, the first bag filter, the first induced draft fan, and After the first dechlorination pre-washing device and booster fan, enter the desulfurization tower from the first flue gas inlet of the desulfurization tower; (2) The low-sulfur flue gas from the head end of the wind box and the end of the wind box of the wind box group passes through the second quencher, the second bag filter, the second induced draft fan and the second dechlorination pre-washing device arranged between the wind box group and the desulfurization tower in sequence After that, enter the desulfurization tower from the second flue gas inlet of the desulfurization tower; (3) The circulation pump installed outside the desulfurization tower pumps the spray liquid in the liquid storage section set at the bottom of the desulfurization tower, and then sprays the spray liquid from the first spray section and the second spray section, and the high-sulfur fume After the gas enters the desulfurization tower through the first flue gas inlet, the desulfurizer sprayed in the first spray section cools down and partially desulfurizes, and then enters the cyclone treatment section, where it rotates upward at a high speed under the action of the cyclone, and is connected with the second spray section. The desulfurizer sprayed by the shower section is rotary cut and mixed at high speed to complete the desulfurization reaction; in the space between the second spray section and the cyclone treatment section, after the low-sulfur flue gas enters the desulfurization tower through the second flue gas inlet, It is mixed with the high-sulfur flue gas flowing upwards after passing through the cyclone treatment section, and contacts and reacts with the desulfurizer sprayed under the second spraying section; (4) The mixed flue gas of purified high-sulfur flue gas and low-sulfur flue gas enters the demister to remove the liquid droplets in the flue gas, and the flue gas after demisting is introduced into the blast furnace gas release tower through the pipe from the flue gas outlet of the desulfurization tower Inside, after being mixed with blast furnace gas in the blast furnace gas release tower, it is released into the atmosphere after being ignited by the burner at the top outlet of the blast furnace gas release tower. 8. The dust removal method of the sintering flue gas split-flow graded desulfurization and dust removal device according to claim 7, characterized in that: in the step (3), one to more spray sections are set above the second spray section. 9. The dust removal method of the sintering flue gas split-flow graded desulfurization and dust removal device according to claim 7, characterized in that: the outlet temperature of the first quencher and the second quencher is controlled at 150-180°C. 10. The dust removal method of the sintering flue gas split-flow graded desulfurization and dust removal device according to claim 7, characterized in that: the outlet temperature of the first chlorine removal pre-washing device and the second chlorine removal pre-washing device is controlled at 80-90°C.

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