A flue gas treatment system, its equipment and method

Abstract

A flue gas treatment system, its equipment and method, belonging to the field of environmental protection technology, including a zinc liquid collector, a zinc liquid recycler, a condenser I, an air pump I, a condenser II, an air pump II, a turbulence injector, a dust collector, an air pump III, a chimney, etc. In the present invention, the zinc liquid collector, the zinc liquid recycler, the condenser I, the air pump I and the turbulence injector form a closed loop of a flue gas circuit to carry out zinc recovery; the condenser II, the air pump II and the turbulence injector form a closed loop of a flue gas circuit to cool down the furnace interior and purify the flue gas; among them, the turbulence injector cools down the flue gas, designs a zinc liquid collector with a special structure, and is arranged in the smelting furnace to collect zinc liquid, increasing the recovery amount by more than 90%. Cooperating with the condenser to further collect solidified substances, it can effectively purify the exhaust flue gas, reduce the treatment load for the subsequent dust collector, has an outstanding flue gas purification effect, reaches a higher emission standard, and has good practicability.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection technologies, and particularly relates to a flue gas treatment system, its equipment and method. Background Art

[0002] During the smelting (steelmaking, ironmaking) process of blast furnaces or shaft furnaces, a large amount of flue gas will inevitably be generated. The harmless treatment of flue gas has always been a technical problem that needs to be overcome in the smelting field. In addition, the flue gas also contains metal vapors, such as zinc vapor. The zinc vapor will repeatedly accumulate in the smelting furnace, resulting in poor air permeability, affecting production efficiency, and even requiring regular furnace shutdowns to remove zinc. In addition, a part of the zinc will be discharged with the flue gas and requires subsequent purification treatment by flue gas treatment equipment to meet the emission standards.

[0003] Specifically, the raw materials during smelting will contain zinc oxide or metallic zinc. During the high-temperature smelting process, zinc oxide is reduced to metallic zinc by reducing gases. The reduced metallic zinc and the metallic zinc contained in the raw materials will be vaporized at high temperatures to form zinc vapor. The zinc vapor is mixed in the flue gas and rises in the furnace with the flue gas. As the rising height increases, the pre-cooling temperature continuously decreases, and the zinc vapor condenses into liquid zinc or solid zinc again and then descends. When it descends to the high-temperature area at the bottom, it will be vaporized and rise repeatedly. In this way, only a small part of the zinc vapor will be discharged with the flue gas, while most of the zinc vapor will repeatedly cycle between vaporization and liquefaction in the furnace. Due to the continuous addition of raw materials, the zinc vapor accumulated in the furnace will become more and more, which will deteriorate the air permeability of the burden, affect the product quality and smelting efficiency, and even affect the normal operation of the smelting furnace, requiring regular production stoppages for maintenance, removal of zinc dust, and reduction of economic benefits. However, during the smelting process, there is no way to solve the problem of zinc vapor accumulation in the furnace, which also leads to the inability to use raw materials with a high zinc content, greatly restricting the selection of production raw materials, with high raw material costs, and unable to carry out the repeated smelting and utilization of scrap steel.

[0004] In this regard, CN111349793A discloses a zinc recovery method and device for blast furnaces or shaft furnaces, in which air outlet holes and return air holes are opened on the furnace wall, and the height pressure difference between the air outlet holes and the return air holes is used to carry out the outflow and reflux of flue gas, and a condenser is set between the outflow and reflux to recover zinc. Although this method can recover some of the enriched zinc vapor, due to the large diameter of the entire furnace, only the flue gas near the furnace wall can flow out through the air outlet holes and enter the condenser, while the flue gas flow in the middle of the furnace will carry the zinc vapor directly upward and will not enter the air outlet holes on the furnace wall. Therefore, this technology can only partially recover zinc vapor, with limited recovery amount and limited effect on improving the furnace condition; for scrap steel raw materials with a high zinc content, the zinc content in the flue gas suddenly increases, and still cannot achieve timely and efficient zinc removal effect; in addition, for scrap steel raw materials with a high zinc content, during smelting, the amount of zinc vapor contained in the flue gas discharged from the furnace also increases, which also poses great difficulties for flue gas treatment. Summary of the Invention

[0005] In view of the problem that it is difficult to eradicate the enrichment of zinc vapor existing in the existing smelting blast furnace or shaft furnace, for scrap steel raw materials with a high zinc content, when the zinc content in the flue gas suddenly increases, the problem of zinc enrichment cannot be eliminated in a timely and efficient manner, and the zinc content in the discharged flue gas also increases accordingly, which also needs to be solved. The present invention provides a flue gas treatment system, its equipment and method, designing a special flue gas treatment system, zinc liquid collector, turbulence injector, etc., to recover zinc in the flue gas in the furnace, with the recovery amount increased by more than 90%, and effectively purifying the exhaust flue gas, reducing the treatment load for subsequent dust removal, and having an outstanding flue gas purification effect. The specific technical solutions are as follows:

[0006] A flue gas treatment system includes a zinc liquid collector 1 and a condenser II 5. The zinc liquid collector 1 is arranged in the smelting furnace. The zinc liquid collector 1 is sequentially connected with a zinc liquid recycler 2, a condenser I 3 and an air pump I 4 through pipelines; the air inlet end of the condenser II 5 is connected to the smoke exhaust port of the smelting furnace through a pipeline. The air outlet end pipeline of the condenser II 5 is divided into two branches. One branch is connected to an air pump II 6, and the other branch is connected to a dust collector 8; the air outlet pipelines of the air pump I 4 and the air pump II 6 converge into a main pipeline, and the main pipeline is connected to a turbulence injector 7, and the turbulence injector 7 is installed on the smelting furnace.

[0007] In the above technical solution, the air outlet end of the dust collector 8 is sequentially connected with an air pump III 9 and a chimney 10 through pipelines.

[0008] In the above technical solution, the zinc liquid collector 1 is arranged at the upper part of the smelting furnace body and is located in the area where the furnace core temperature is 910°C ± 30°C.

[0009] In the above technical solution, the turbulence injector 7 is located above the zinc liquid collector 1 and is located in the area where the furnace core temperature is 700°C - 850°C.

[0010] In the above technical solution, the smoke exhaust port of the smelting furnace is located at the top of the smelting furnace and is located above the turbulence injector 7.

[0011] In the above technical solution, the zinc liquid collector 1 is located above the feed inlet of the smelting furnace.

[0012] In the above technical solution, the temperature in the zinc liquid recycler 2 is maintained at 430 - 850°C; a low-temperature recovery cylinder is connected to the bottom outlet of the zinc liquid recycler 2.

[0013] In the above technical solution, the condensation temperature of the condenser I 3 is below 100°C; a discharge trough 3.1 with openings at both ends is arranged at the bottom of the condenser I 3. The openings at both ends of the discharge trough 3.1 are sealed by a stopper 3.11, and a receiving trough is arranged inside the discharge trough 3.1; the structure and condensation temperature of the condenser II 5 are the same as those of the condenser I 3.

[0014] In the above technical solution, an electric valve and a flowmeter are provided on the pipeline.

[0015] A zinc liquid collector is used for the above-mentioned flue gas treatment system. The zinc liquid collector 1 includes an upper ring groove 1.1 and a lower ring groove 1.2. The upper ring groove 1.1 is located above the lower ring groove 1.2; the upper ring groove 1.1 and the lower ring groove 1.2 are connected by a connecting piece 1.4; the upper ring groove 1.1 is composed of a plurality of concentric ring grooves, and the plurality of concentric ring grooves are connected by an upper flow channel groove 1.11, and the discharge port of the upper flow channel groove 1.11 is connected to the furnace wall outlet pipeline; the lower ring groove 1.2 is composed of a plurality of concentric ring grooves, and the plurality of concentric ring grooves are connected by a lower flow channel groove 1.21, and the discharge port of the lower flow channel groove 1.21 is connected to the furnace wall outlet pipeline; the concentric ring grooves of the upper ring groove 1.1 and the lower ring groove 1.2 are arranged in an alternating manner of outer ring and inner ring; the periphery of the upper ring groove 1.1 is fixed to the inner wall of the smelting furnace through a connecting piece 1.3.

[0016] In the above technical solution, the zinc liquid collector 1 is integrally formed; the material of the zinc liquid collector 1 is graphite material, and after forming, it is prepared by high-temperature sintering at 3000°C to 3200°C; or the zinc liquid collector 1 is a high-temperature resistant material resistant to more than 1100°C.

[0017] In the above technical solution, the inner bottom surfaces of the grooves of the upper ring groove 1.1, the upper flow channel groove 1.11, the lower ring groove 1.2, and the lower flow channel groove 1.21 are slopes, and the slopes incline downward toward the furnace wall outlet pipeline, facilitating the liquid to flow toward the furnace wall outlet pipeline faster.

[0018] A turbulence injector is used for the above-mentioned flue gas treatment system. The turbulence injector 7 is specifically a gas turbulence nozzle. The injection surface of the turbulence injector 7 is provided with three forms of nozzles, namely an upper layer nozzle 7.1, a middle layer nozzle 7.2, and a lower layer nozzle 7.3. The injection angle of the middle layer nozzle 7.2 is a horizontal angle of 90° for direct injection, and the injection angles of the upper layer nozzle 7.1 and the lower layer nozzle 7.3 are horizontal angles of 40° to 70° for oblique injection, and the injection directions of the upper layer nozzle 7.1 and the lower layer nozzle 7.3 are opposite.

[0019] In the above technical solution, there are several nozzles in the upper layer nozzle 7.1, and the angles between the several nozzles are the same or different; there are several nozzles in the lower layer nozzle 7.3, and the angles between the several nozzles are the same or different;

[0020] The flue gas treatment method of the above-mentioned flue gas treatment system includes the following steps:

[0021] The flue gas generated during smelting passes through the gap between the upper and lower layers of the zinc liquid collector 1, rises directly to the smoke exhaust port of the smelting furnace, enters the condenser II 5. After the flue gas is cooled, the substances that can be condensed and solidified in the flue gas fall to the bottom of the condenser. The flue gas that cannot be solidified becomes low-temperature flue gas. Part of the low-temperature flue gas enters the dust collector 8 for dust removal and is then discharged through the chimney 10; another part of the low-temperature flue gas is pumped into the turbulence injector 7 by the air pump II 6. The turbulence injector 7 injects low-temperature gas into the smelting furnace. After that, the hot flue gas generated during continuous smelting rises and meets the low-temperature gas or naturally cools down. The zinc vapor in the flue gas liquefies and falls into the zinc liquid collector 1 and then flows into the zinc liquid recovery device 2 through the pipeline. The temperature of the zinc liquid recovery device 2 can keep the zinc in a liquid state. After a certain amount of zinc is collected, it is received and recovered with a low-temperature recovery bucket; a small amount of flue gas that flows into the zinc liquid recovery device 2 along with the zinc liquid enters the condenser I 3 for cooling, and then successively passes through the air pump I 4 and the turbulence injector 7 and returns to the smelting furnace.

[0022] In the above method, according to the calculated zinc production during smelting, the system controls the air pump II 6 and the air pump I 4 to start continuously or intermittently.

[0023] In the above method, more than 90% of the zinc can be collected in the zinc liquid recovery device 2, and the remaining zinc is collected by the condenser II 5 and the condenser I 3.

[0024] In the above method, the zinc collected by the condenser II 5 and the condenser I 3 is a solid; among them, the trace zinc vapor that escapes with the flue gas from the zinc liquid recovery device 2 enters the condenser I 3 for solidification. The solidified zinc falls into the receiving tank of the condenser I 3. After a certain amount is collected, the baffle plug 3.11 of the condenser I 3 is opened, and the receiving tank is pulled out or pushed out from the discharge tank 3.1 of the condenser I 3 to realize the replacement of the receiving tank.

[0025] A flue gas treatment system, its equipment and method of the present invention, compared with the prior art, has the beneficial effects as follows:

[0026] First, the zinc liquid collector with a special structure is designed in the flue gas treatment system of the present invention and is arranged in the smelting furnace, located in the area where the core temperature is 910°C ± 30°C. This temperature area is the critical point of zinc gas liquefaction, the place where the zinc enrichment is the densest, and the best area section for collecting zinc liquid. When cold gas is injected, the pre-cooled and liquefied zinc liquid falls into the zinc liquid collector and cannot immediately gasify completely and then flows into the zinc liquid recovery device, with high zinc removal efficiency. In addition, when cold gas is injected, the temperature in this area will slightly decrease accordingly, which is also beneficial to increasing the zinc liquid collection amount and purifying the flue gas.

[0027] Second, the zinc liquid recovery device is designed in the flue gas treatment system of the present invention. The bottom of the zinc liquid recovery device is conical, which is convenient for the liquid to flow down. The temperature of the zinc liquid recovery device is maintained at the liquid temperature of zinc, which can ensure that it does not solidify and will not gasify, thereby ensuring fluidity and smooth collection.

[0028] 3. The flue gas treatment system of the present invention is designed with a condenser I behind the zinc liquid recovery device. When the amount of zinc is insufficient to fill the pipeline, part of the flue gas will flow into the zinc liquid recovery device along with the liquid zinc and enter the condenser I. The condenser I can cool the flue gas, collect solidifiable substances in the flue gas, and further capture the escaped trace zinc. The cooled flue gas flows back into the smelting furnace to form a closed loop without causing air pollution. The flue gas cooling can also protect subsequent equipment and extend the service life of subsequent pipelines and the service life of the air pump I.

[0029] Fourth, the flue gas treatment system of the present invention is designed with a special structure of the turbulent injector above the zinc liquid collector, which is used to inject low-temperature gas. The low-temperature gas comes from the gas after the flue gas of the smelting furnace is cooled by condenser II. On the one hand, condenser II can cool the flue gas and provide a gas source for the turbulent injector to form a closed loop. It does not need to quote external gas, will not introduce external impurities, and is not affected by the external environment; on the other hand, condenser II can assist in capturing some trace escaped zinc and some solidifiable substances, reduce the flue gas treatment load for the dust collector, and extend the service life of the dust collector filter. In addition, after the flue gas is cooled by condenser II, it can protect subsequent equipment and extend the service life of subsequent pipelines, air pump II and dust collector.

[0030] 5. The present invention designs a structure of a zinc liquid collector for a flue gas treatment system. The upper ring groove and the lower ring groove are designed as upper and lower layers, which are not on the same plane and will not block the passage of the flue gas, thereby ensuring that the smelting flue gas can smoothly rise through the zinc liquid collector; the concentric annular grooves of the upper ring groove and the lower ring groove are staggered with the outer circle and the inner circle, which can well receive the liquid zinc, that is, the area that the upper ring groove cannot receive the zinc liquid is supplemented by the lower ring groove to achieve full-area reception, effectively improving the collection amount and collection efficiency. When the zinc enrichment amount is not large, the system can achieve intermittent operation due to the high collection efficiency.

[0031] The upper and lower ring grooves of the zinc liquid collector are designed to be connected by flow channel grooves to ensure the smooth flow of zinc liquid. In addition, a sloped groove bottom can be designed to increase the flow rate and reduce liquid accumulation. The zinc liquid collector is designed to be made of high temperature resistant material to ensure its service life.

[0032] VI. For the flue gas treatment system, the present invention designs the structure of a spoiler injector. The injection surface of the spoiler injector is provided with nozzles in three forms. The injection angle of the middle nozzle is a horizontal angle of 90° for direct injection, and the injection angles of the upper and lower nozzles are horizontal angles of 40° - 70° for oblique injection. The injection directions of the upper and lower nozzles are opposite. This design can effectively increase the injection area of the gas in the horizontal direction. After the air flow hits the furnace wall of the smelting furnace, it can change the flow direction, further generating a spoiler effect, forming a cooling gas layer without dead corners, ensuring effective cooling of the flue gas, liquefying zinc vapor, and effectively reducing the escape of zinc vapor from the exhaust port. And it reduces the temperature of the liquefied zinc, so that the liquefied zinc will not easily vaporize repeatedly. In addition, the cold gas layer can cool the flue gas, further reducing the temperature of the discharged flue gas and reducing the energy consumption of the condenser.

[0033] VII. For the flue gas treatment system, the present invention designs the structure of the condenser, that is, a discharge trough with both ends open is arranged at the bottom of the condenser. The two open ends of the discharge trough are sealed by stoppers, and a receiving trough is arranged inside the discharge trough; it is convenient to replace the receiving trough, effectively preventing solidified substances from sticking to the bottom and causing discharge blockage.

[0034] VIII. For the system, the present invention also designs a flue gas treatment method. This flue gas treatment method can control the air pump II and the air pump I to start continuously or intermittently according to the calculated zinc production during smelting. More than 90% of the zinc can be collected in the zinc liquid recovery device, and the remaining zinc is collected by the condenser II and the condenser I; there is a breakthrough improvement in the zinc recovery effect, which is applicable to any smelting raw material with a high zinc content, completely eliminating the need to stop production for zinc cleaning, and can keep the smelting gas in the furnace flowing smoothly for a long time, ensuring that the quality of the smelting products does not decline. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of a flue gas treatment system according to an embodiment of the present invention;

[0036] Figure 2 is a top view of a zinc liquid collector according to an embodiment of the present invention;

[0037] Figure 3 is a top view of the lower ring groove of a zinc liquid collector according to an embodiment of the present invention;

[0038] Figure 4 is a side view of a zinc liquid collector according to an embodiment of the present invention;

[0039] Figure 5 is a schematic diagram of the condenser I of a flue gas treatment system according to an embodiment of the present invention;

[0040] Figure 6 is a front view of the injection surface of a spoiler injector according to an embodiment of the present invention;

[0041] Figure 7 Top view of a spoiler injector according to an embodiment of the present invention;

[0042] Figure 8 Schematic diagram of the upper nozzle of a spoiler injector according to an embodiment of the present invention;

[0043] Figure 9 Schematic diagram of the middle nozzle of a spoiler injector according to an embodiment of the present invention;

[0044] Figure 10 Schematic diagram of the lower nozzle of a spoiler injector according to an embodiment of the present invention;

[0045] In the figure: 1 - Zinc liquid collector, 1.1 - Upper ring groove, 1.11 - Up - flow channel groove, 1.2 - Lower ring groove, 1.21 - Down - flow channel groove, 1.3 - Connector, 1.4 - Connecting piece, 2 - Zinc liquid recycler, 3 - Condenser I, 3.1 - Discharge chute, 3.11 - Blocking plug, 4 - Air pump I, 5 - Condenser II, 6 - Air pump II, 7 - Spoiler injector, 7.1 - Upper nozzle, 7.2 - Middle nozzle, 7.3 - Lower nozzle, 8 - Dust collector, 9 - Air pump III, 10 - Chimney. Detailed implementation manners

[0046] The following combines specific implementation cases and attached Figures 1-10 to further illustrate the present invention, but the present invention is not limited to these embodiments.

[0047] Embodiment 1

[0048] For a 30m blast furnace smelting furnace, when using scrap iron and scrap steel with a high zinc content as raw materials, due to zinc enrichment problems, the blast resistance during smelting is too high, and it is necessary to frequently stop production to clean zinc. Stopping production to remove zinc will cause solidified zinc to remain in the furnace wall gaps. Frequent production stoppages and incomplete cleaning will seriously affect the production progress and smelting efficiency. The solidified zinc in the furnace wall gaps also has a great impact on the furnace body life. After system transformation, the structure is as follows:

[0049] A flue gas treatment system, such as Figure 1As shown in the figure, it includes a molten zinc collector 1 and a condenser II 5. The molten zinc collector 1 is arranged at the upper part inside the smelting furnace body and is located in the area where the core temperature of the furnace is 910 °C. The molten zinc collector 1 is sequentially connected with a molten zinc recycler 2, a condenser I 3 and an air pump I 4 through pipelines; the air inlet end of the condenser II 5 is connected to the smoke exhaust port of the smelting furnace through a pipeline. The air outlet end pipeline of the condenser II 5 is divided into two branches. One branch is connected to an air pump II 6, and the other branch is connected to a dust collector 8. The air outlet end of the dust collector 8 is sequentially connected with an air pump III 9 and a chimney 10 through pipelines; the air outlet pipelines of the air pump I 4 and the air pump II 6 converge into a main pipeline, and the main pipeline is connected to a spoiler injector 7. The spoiler injector 7 is installed on the smelting furnace. The spoiler injector 7 is located above the molten zinc collector 1 and is located in the area where the core temperature of the furnace is 700 °C. The smoke exhaust port of the smelting furnace is located at the top of the smelting furnace and is located above the spoiler injector 7. The molten zinc collector 1 is located above the feed inlet of the smelting furnace.

[0050] Among them, during use, the temperature inside the molten zinc recycler 2 is maintained at 430 - 700 °C; a low-temperature recovery cylinder is connected to the bottom outlet of the molten zinc recycler 2. During use, the condensation temperature of the condenser I 3 is below 100 °C; as Figure 5 shown, a discharge trough 3.1 with openings at both ends is arranged at the bottom of the condenser I 3. The openings at both ends of the discharge trough 3.1 are sealed by stoppers 3.11, and a receiving trough is arranged inside the discharge trough 3.1; the structure and condensation temperature of the condenser II 5 are the same as those of the condenser I 3.

[0051] Among them, electric valves are arranged on the pipelines and are controlled by an electric control system; a flowmeter is arranged at the air inlet end of the air pump II 6, and a flowmeter is arranged at the air inlet end of the spoiler injector 7.

[0052] A molten zinc collector for the above-mentioned flue gas treatment system, as Figures 2-4As shown, the zinc liquid collector 1 includes an upper ring groove 1.1 and a lower ring groove 1.2, and the upper ring groove 1.1 is located above the lower ring groove 1.2; the upper ring groove 1.1 and the lower ring groove 1.2 are connected by a connecting piece 1.4; the upper ring groove 1.1 is composed of multiple concentric ring grooves, and the multiple concentric ring grooves are communicated by an upper flow channel groove 1.11, and the discharge port of the upper flow channel groove 1.11 is connected to the furnace wall outlet pipe; the lower ring groove 1.2 is composed of multiple concentric ring grooves, and the multiple concentric ring grooves are communicated by a lower flow channel groove 1.21, and the discharge port of the lower flow channel groove 1.21 is connected to the furnace wall outlet pipe; the concentric ring grooves of the upper ring groove 1.1 and the lower ring groove 1.2 are arranged in an alternating manner of outer ring and inner ring; the periphery of the upper ring groove 1.1 is fixed to the inner wall of the smelting furnace through a connecting piece 1.3. The zinc liquid collector 1 is integrally formed; the material of the zinc liquid collector 1 is graphite material, and after forming, it is prepared by high-temperature sintering at 3000°C to 3200°C; or the zinc liquid collector 1 is a high-temperature resistant material that can withstand temperatures above 1100°C. The inner bottom surfaces of the grooves of the upper ring groove 1.1, the upper flow channel groove 1.11, the lower ring groove 1.2, and the lower flow channel groove 1.21 are inclined planes, and the inclined planes incline towards the furnace wall outlet pipe, facilitating the liquid to flow towards the furnace wall outlet pipe faster.

[0053] A flow disturbance injector is used for the above-mentioned flue gas treatment system, such as Figures 6-10 As shown, the flow disturbance injector 7 is specifically a gas flow disturbance nozzle. The injection surface of the flow disturbance injector 7 is provided with three forms of nozzles, namely an upper layer nozzle 7.1, a middle layer nozzle 7.2, and a lower layer nozzle 7.3. The injection angle of the middle layer nozzle 7.2 is a horizontal angle of 90° for direct injection, and the injection angles of the upper layer nozzle 7.1 and the lower layer nozzle 7.3 are horizontal angles of 40° for oblique injection, and the injection directions of the upper layer nozzle 7.1 and the lower layer nozzle 7.3 are opposite.

[0054] The flue gas treatment method of the above-mentioned flue gas treatment system includes the following steps:

[0055] The flue gas generated by smelting passes through the gap between the upper and lower layers of the zinc liquid collector 1, rises directly to the smoke exhaust port of the smelting furnace, enters the condenser II 5, and after the flue gas is refrigerated, the substances that can be condensed and solidified in the flue gas fall to the bottom of the condenser, and the flue gas that cannot be solidified becomes low-temperature flue gas. Part of the low-temperature flue gas enters the dust collector 8 for dust removal and is then discharged through the chimney 10; another part of the low-temperature flue gas is pumped into the flow disturbance injector 7 by the air pump II 6. The flow disturbance injector 7 injects low-temperature gas into the smelting furnace. Then, the hot flue gas generated by continuous smelting rises and encounters the low-temperature gas or naturally cools down. The zinc vapor in the flue gas liquefies and falls into the zinc liquid collector 1, and then flows into the zinc liquid recovery device 2 through the pipeline. The temperature of the zinc liquid recovery device 2 can keep the zinc in a liquid state. After collecting a certain amount, it is received and recovered with a low-temperature recovery bucket; a small amount of flue gas flowing into the zinc liquid recovery device 2 along with the zinc liquid enters the condenser I 3 for cooling, and then sequentially passes through the air pump I 4 and the flow disturbance injector 7 and returns to the smelting furnace.

[0056] Under the long-term use of the raw materials with a high zinc content, according to the calculated amount of zinc produced by smelting, the system controls the air pump II 6 and the air pump I 4 to start continuous operation.

[0057] During the use process, calculate the theoretical production amount of zinc within a one-month interval, and weigh the recovered amount of zinc, and it is obtained that 91.6% of the zinc amount can be collected in the zinc liquid recovery device 2.

[0058] The remaining zinc is collected by the condenser II 5 and the condenser I 3, and the zinc collected by the condenser II 5 and the condenser I 3 is a solid; among them, the trace zinc vapor escaping with the flue gas from the zinc liquid recovery device 2 enters the condenser I 3 for solidification, and the solidified zinc falls into the material receiving tank of the condenser I 3. After a certain amount is collected, open the baffle plug 3.11 of the condenser I 3, and draw out or push out the material receiving tank from the discharge tank 3.1 of the condenser I 3 to realize the replacement of the material receiving tank.

[0059] Within a one-month interval, weigh the total amount of zinc collected by the zinc liquid recovery device 2 (91.6%), and the mass of the solids collected by the condenser II and the condenser I. The sum is 5.8% greater than the theoretically calculated production amount of zinc, that is, the theoretical calculation is 100%, and the actual collected material is 105.8%. Analysis shows that on the one hand, there is a deviation between the theoretically calculated zinc content in the raw materials and the actual zinc content. On the other hand, the solids collected in the condenser II and the condenser I contain other impurities in addition to zinc.

[0060] A flue gas treatment system after transformation in this embodiment has good effects in removing flue gas impurities and removing zinc. Especially, the achievement of zinc removal has been greatly improved, and there is no need to stop production for zinc removal, which does not affect the production efficiency.

Claims

1. A flue gas treatment system, characterized in that, The system includes a zinc liquid collector (1) and a condenser II (5). The zinc liquid collector (1) is arranged inside the smelting furnace. The zinc liquid collector (1) is sequentially connected with a zinc liquid recycler (2), a condenser I (3), and an air pump I (4) through pipelines. The air inlet end of the condenser II (5) is connected to the smoke exhaust port of the smelting furnace through a pipeline. The air outlet end pipeline of the condenser II (5) is divided into two branches. One branch is connected to an air pump II (6), and the other branch is connected to a dust collector (8). The air outlet pipelines of the air pump I (4) and the air pump II (6) converge into a main pipeline, and the main pipeline is connected to a spoiler injector (7). The spoiler injector (7) is installed on the smelting furnace. The zinc liquid collector (1) includes an upper ring groove (1.1) and a lower ring groove (1.2). The upper ring groove (1.1) is located above the lower ring groove (1.2). The upper ring groove (1.1) and the lower ring groove (1.2) are connected by a connecting piece (1.4). The upper ring groove (1.1) is composed of multiple concentric ring grooves, and the multiple concentric ring grooves are connected by an upper flow channel groove (1.11). The discharge port of the upper flow channel groove (1.11) is connected to the furnace wall outlet pipeline. The lower ring groove (1.2) is composed of multiple concentric ring grooves, and the multiple concentric ring grooves are connected by a lower flow channel groove (1.21). The discharge port of the lower flow channel groove (1.21) is connected to the furnace wall outlet pipeline. The concentric ring grooves of the upper ring groove (1.1) and the lower ring groove (1.2) are arranged in a staggered manner with the outer ring and the inner ring. The periphery of the upper ring groove (1.1) is fixed to the inner wall of the smelting furnace through a connecting piece (1.3). The spoiler injector (7) is specifically a gas spoiler nozzle. The injection surface of the spoiler injector (7) is provided with three forms of nozzles, namely an upper layer nozzle (7.1), a middle layer nozzle (7.2), and a lower layer nozzle (7.3). The injection angle of the middle layer nozzle (7.2) is a horizontal angle of 90° for direct injection. The injection angles of the upper layer nozzle (7.1) and the lower layer nozzle (7.3) are 40° - 70° for oblique injection, and the injection directions of the upper layer nozzle (7.1) and the lower layer nozzle (7.3) are opposite.

2. The flue gas treatment system according to claim 1, characterized in that, The air outlet end of the dust collector (8) is sequentially connected with an air pump III (9) and a chimney (10) through pipelines. The zinc liquid collector (1) is arranged in the upper part of the smelting furnace body and is located in the area where the core temperature of the furnace is 910°C ± 30°C. The spoiler injector (7) is located above the zinc liquid collector (1) and is located in the area where the core temperature of the furnace is 700°C - 850°C. The smoke exhaust port of the smelting furnace is located at the top of the smelting furnace and is located above the spoiler injector (7).

3. The flue gas treatment system according to claim 1, characterized in that, The temperature inside the zinc liquid recycler (2) is maintained at 430 - 850°C. The bottom outlet of the zinc liquid recycler (2) is connected with a low-temperature recovery cylinder. The condensation temperature of the condenser I (3) is below 100°C. The bottom of the condenser I (3) is provided with a discharge trough (3.1) with openings at both ends. The openings at both ends of the discharge trough (3.1) are sealed by a stopper (3.11). A receiving trough is arranged inside the discharge trough (3.1). The structure and condensation temperature of the condenser II (5) are the same as those of the condenser I (3).

4. The flue gas treatment system according to claim 1, characterized in that, The zinc liquid collector (1) is integrally formed; the material of the zinc liquid collector (1) is graphite, and after forming, it is prepared by high-temperature sintering at 3000°C to 3200°C.

5. The flue gas treatment system according to claim 1, characterized in that, The inner bottom surfaces of the upper ring groove (1.1), the upper flow channel groove (1.11), the lower ring groove (1.2) and the lower flow channel groove (1.21) are slopes, and the slopes incline downward towards the furnace wall outlet pipe.

6. A flue gas treatment method, using the flue gas treatment system according to claim 1, characterized in that, It includes the following steps: The flue gas generated by smelting passes through the gap between the upper and lower layers of the zinc liquid collector (1), rises directly to the smoke outlet of the smelting furnace, enters the condenser II (5), and after the flue gas is cooled, the substances that can be condensed and solidified in the flue gas fall to the bottom of the condenser. The flue gas that cannot be solidified becomes low-temperature flue gas. A part of the low-temperature flue gas enters the dust collector (8) for dust removal and is then discharged through the chimney (10); another part of the low-temperature flue gas is pumped into the spoiler injector (7) by the air pump II (6). The spoiler injector (7) injects low-temperature gas into the smelting furnace. Then, the hot flue gas generated by continuous smelting rises and meets the low-temperature gas or naturally cools down. The zinc vapor in the flue gas liquefies and falls into the zinc liquid collector (1), and then flows into the zinc liquid recovery device (2) along the pipeline. The temperature of the zinc liquid recovery device (2) can keep the zinc in a liquid state. After a certain amount of zinc is collected, it is received and recovered with a low-temperature recovery bucket; a small amount of flue gas flowing into the zinc liquid recovery device (2) along with the zinc liquid enters the condenser I (3) for cooling, and then successively passes through the air pump I (4) and the spoiler injector (7) and returns to the smelting furnace.

7. The flue gas treatment method according to claim 6, characterized in that, The air pump II (6) and the air pump I (4) operate continuously or intermittently.

8. The flue gas treatment method according to claim 6, characterized in that, The zinc liquid recovery device (2) can collect more than 90% of the zinc amount, and the remaining zinc is collected by the condenser II (5) and the condenser I (3); the zinc collected by the condenser II (5) and the condenser I (3) is solid matter; among them, the trace zinc vapor escaping along with the flue gas from the zinc liquid recovery device (2) enters the condenser I (3) for solidification, and the solidified zinc falls into the receiving tank of the condenser I (3). After a certain amount is collected, the stopper (3.11) of the condenser I (3) is opened, and the receiving tank is pulled out or pushed out from the discharge tank (3.1) of the condenser I (3) to realize the replacement of the receiving tank.

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