Flue gas purification system of industrial silicon heating furnace

Abstract

The utility model discloses a flue gas purification system for an industrial silicon heating furnace, which relates to the technical field of industrial silicon production and comprises a main flue gas channel and an auxiliary flue gas channel. The main flue gas channel is sequentially provided with a flue gas leading-out pipe, a waste heat boiler, an SCR denitration device, a negative pressure bag-type dust collector and a flue gas leading-back pipe in the flowing direction of flue gas, the flue gas leading-out pipe and the flue gas leading-back pipe communicate with the output port and the input port correspondingly, and a flow dividing port is formed in the main flue gas channel; the shunting port is positioned between the negative-pressure bag-type dust collector and the flue gas guide-back pipe; the first end of the auxiliary smoke channel communicates with the flow dividing opening, and a discharging opening is formed in the second end of the auxiliary smoke channel. According to the flue gas purification system for the industrial silicon heating furnace, part of flue gas after purification treatment is guided back into the industrial silicon heating furnace again, waste heat of the flue gas is continuously used for smelting industrial silicon, heat energy loss is greatly reduced, energy consumption needed by heating of the industrial silicon heating furnace is reduced, and heat energy utilization efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial silicon production, in particular to an industrial silicon thermal furnace fume purification system. Background Art

[0002] Industrial silicon is produced by smelting silica with a carbonaceous reducing agent in a hot furnace at high temperature. The flue gas generated during the smelting process of industrial silicon is of high temperature and contains a large amount of impurities and pollutants. At present, the flue gas generated by the industrial silicon hot furnace is usually discharged directly after purification, or a waste heat boiler is set up to utilize the waste heat of the flue gas once before discharging. However, the flue gas after being utilized by the waste heat boiler still has a high temperature, and the utilization efficiency of the waste heat of the flue gas using the waste heat boiler is not high, and the heat loss is large. Utility Model Content

[0003] The main purpose of the utility model is to propose an industrial silicon thermal furnace flue gas purification system, aiming to solve the technical problems in the prior art of low efficiency and large heat loss in utilizing flue gas waste heat using waste heat boilers during the industrial silicon thermal furnace flue gas purification process.

[0004] To achieve the above-mentioned purpose, the industrial silicon thermal furnace flue gas purification system proposed in the utility model is used for purifying the flue gas generated by the industrial silicon thermal furnace. The industrial silicon thermal furnace is provided with an input port and an output port. The industrial silicon thermal furnace flue gas purification system comprises a main flue gas channel and a secondary flue gas channel. The main flue gas channel is provided with a flue gas outlet pipe, a waste heat boiler, an SCR denitrification device, a negative pressure bag filter and a flue gas return pipe in sequence along the flow direction of the flue gas. The flue gas outlet pipe and the flue gas return pipe are respectively connected to the output port and the input port. A diversion port is provided on the main flue gas channel, and the diversion port is located between the negative pressure bag filter and the flue gas return pipe. The first end of the secondary flue gas channel is connected to the diversion port, and the second end of the secondary flue gas channel is provided with a discharge port.

[0005] In one embodiment, the main flue gas channel includes a first channel, a second channel and a third channel, and the first channel, the second channel and the third channel are connected in sequence along the flow direction of the flue gas to form an n-type structure, the end of the first channel away from the second channel is connected to the output port, the end of the third channel away from the second channel is connected to the input port, the diversion port is opened on the third channel, the waste heat boiler and the negative pressure bag dust collector are respectively arranged on the first channel and the third channel, and the waste heat boiler and the negative pressure bag dust collector are both arranged along the flow direction of the flue gas.

[0006] In one embodiment, the diversion port is opened on a side of the third channel away from the first channel, and the secondary smoke channel extends in a direction away from the first channel.

[0007] In one embodiment, a first fan is disposed on the smoke return pipe, and a second fan is disposed on the auxiliary smoke channel.

[0008] In one embodiment, a first flow sensor is disposed in the smoke return pipe, and the first flow sensor is disposed away from the first fan. A second flow sensor is disposed in the secondary smoke channel, and the second flow sensor is disposed away from the second fan.

[0009] In one embodiment, a chimney is provided at the second end of the secondary flue gas channel, the chimney is provided with the discharge port, and a wet desulfurization device is provided on the secondary flue gas channel, and the wet desulfurization device is located between the first end and the second end.

[0010] In one embodiment, a cyclone dust collector is further provided on the main flue gas channel, and the cyclone dust collector is located between the waste heat boiler and the SCR denitrification device.

[0011] In one embodiment, the length of the smoke return pipe is less than 45 m.

[0012] In one embodiment, the waste heat boiler is provided with an adsorption device for adsorbing solid particles.

[0013] In one embodiment, the exhaust port is connected to a carbon dioxide recovery device.

[0014] The industrial silicon thermal furnace flue gas purification system proposed in the utility model utilizes and purifies the flue gas generated by the industrial silicon thermal furnace by sequentially arranging a waste heat boiler, an SCR denitrification device and a negative pressure bag filter on the main flue gas pipeline. The flue gas still has a relatively high temperature after the purification treatment is completed. Part of the flue gas after the purification treatment is re-introduced into the industrial silicon thermal furnace, and the waste heat of the flue gas is continued to be used for the smelting of industrial silicon, thereby greatly reducing the heat energy loss, reducing the energy consumption required for heating the industrial silicon thermal furnace, and improving the efficiency of heat energy utilization, which is more energy-saving and efficient. In addition, in the industrial silicon thermal furnace flue gas purification system proposed in the utility model, the SCR denitrification device is arranged before the negative pressure bag filter, so that the flue gas flowing out of the industrial silicon thermal furnace first enters the SCR denitrification device for denitrification when the temperature is relatively high. The SCR denitrification device has a higher denitrification efficiency, a better purification effect, and is more environmentally friendly in a higher temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0016] Figure 1 The utility model provides a schematic structural diagram of an industrial silicon thermal furnace fume purification system according to an embodiment of the present invention.

[0017] Description of Figure Numbers:

[0018] 10. Main flue gas channel; 11. Flue gas outlet pipe; 12. Waste heat boiler; 13. SCR denitrification device; 14. Negative pressure bag filter; 15. Flue gas return pipe; 16. Cyclone dust collector; 17. Diversion port; 18. First fan; 20. Auxiliary flue gas channel; 21. Second fan; 22. Chimney.

[0019] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0023] At present, the flue gas generated by industrial silicon thermal furnaces is usually discharged directly after purification, or a waste heat boiler is set up to utilize the waste heat of the flue gas once before discharging. However, the flue gas after being utilized by the waste heat boiler still has a relatively high temperature, and the utilization efficiency of the waste heat of the flue gas using the waste heat boiler is not high, and the heat loss is relatively large.

[0024] The utility model proposes an industrial silicon thermal furnace flue gas purification system, which is used for purifying the flue gas generated by the industrial silicon thermal furnace. The industrial silicon thermal furnace is provided with an input port and an output port. The industrial silicon thermal furnace flue gas purification system proposed by the utility model comprises a main flue gas channel 10 and an auxiliary flue gas channel 20. The main flue gas channel 10 is provided with a flue gas outlet pipe 11, a waste heat boiler 12, an SCR denitrification device 13, a negative pressure bag filter 14 and a flue gas return pipe 15 in sequence along the flow direction of the flue gas. The flue gas outlet pipe 11 and the flue gas return pipe 15 are connected to the output port and the input port respectively. A diversion port 17 is provided on the main flue gas channel 10, and the diversion port 17 is located between the negative pressure bag filter 14 and the flue gas return pipe 15. The first end of the auxiliary flue gas channel 20 is connected to the diversion port 17, and the second end of the auxiliary flue gas channel 20 is provided with a discharge port.

[0025] It can be explained that the flue gas generated by the industrial silicon thermal furnace enters the flue gas outlet pipe 11 from the output port, and flows along the flue gas outlet pipe 11 to the waste heat boiler 12, the SCR denitrification device 13 and the negative pressure bag dust collector 14 for treatment in sequence. The waste heat boiler 12 uses the thermal energy in the flue gas to generate electricity or heat, thereby realizing the secondary utilization of energy, and can make the larger particles in the flue gas settle in the waste heat boiler 12, and the nitrogen oxides in the flue gas are converted into harmless components through the SCR denitrification device 13, and the smaller particles in the flue gas are filtered through the negative pressure bag dust collector 14 to purify the flue gas; the purified flue gas is diverted at the diversion port 17, and part of the flue gas is returned to the industrial silicon thermal furnace through the flue gas inlet pipe, and the other part of the flue gas is discharged from the exhaust port through the auxiliary flue gas channel 20.

[0026] The industrial silicon thermal furnace flue gas purification system proposed in the utility model utilizes and purifies the flue gas generated by the industrial silicon thermal furnace by sequentially arranging a waste heat boiler 12, an SCR denitrification device 13 and a negative pressure bag filter 14 on the main flue gas pipeline. The flue gas still has a relatively high temperature after the purification treatment is completed. Part of the flue gas after the purification treatment is re-introduced into the industrial silicon thermal furnace, and the waste heat of the flue gas is continued to be used for the smelting of industrial silicon, thereby greatly reducing the heat energy loss, reducing the energy consumption required for heating the industrial silicon thermal furnace, and improving the efficiency of heat energy utilization, which is more energy-saving and efficient. In addition, in the industrial silicon thermal furnace flue gas purification system proposed in the utility model, the SCR denitrification device 13 is arranged before the negative pressure bag filter 14, so that the flue gas flowing out of the industrial silicon thermal furnace first enters the SCR denitrification device 13 for denitrification when the temperature is relatively high. The SCR denitrification device 13 has a higher denitrification efficiency, a better purification effect, and is more environmentally friendly in a higher temperature environment.

[0027] In one embodiment, the main flue gas channel 10 includes a first channel, a second channel and a third channel, and the first channel, the second channel and the third channel are connected in sequence along the flow direction of the flue gas to form an n-type structure, the end of the first channel away from the second channel is connected to the output port, the end of the third channel away from the second channel is connected to the input port, the diversion port 17 is opened on the third channel, the waste heat boiler 12 and the negative pressure bag dust collector 14 are respectively arranged on the first channel and the third channel, and the waste heat boiler 12 and the negative pressure bag dust collector 14 are both arranged along the flow direction of the flue gas.

[0028] See also Figure 1 The first channel and the third channel are both connected to the industrial silicon thermal furnace, and the first channel and the third channel are arranged side by side and at intervals, and the second channel is connected between the first channel and the third channel, so that the first channel, the second channel and the third channel form an n-type structure. The waste heat boiler 12, the SCR denitrification device 13 and the negative pressure bag filter 14 are respectively located on the first channel, the second channel and the third channel, so that the waste heat boiler 12, the SCR denitrification device 13 and the negative pressure bag filter 14 are close to each other, so that the flue gas discharged from the industrial silicon thermal furnace enters the waste heat boiler 12, the SCR denitrification device 13 and the negative pressure bag filter 14 at a higher temperature for utilization and purification. The flue gas after treatment is refluxed into the industrial silicon thermal furnace when it still has a higher temperature, thereby reducing the heat loss in the process of flue gas utilization and purification, and improving the heat utilization efficiency.

[0029] In one embodiment, the diversion port 17 is opened on a side of the third channel away from the first channel, and the secondary smoke channel 20 extends in a direction away from the first channel.

[0030] It should be noted that the carbon dioxide in the flue gas will be enriched at the diversion port 17 and discharged into the atmosphere through the auxiliary flue gas channel 20. The auxiliary flue gas channel 20 extends in the direction away from the first channel, which can avoid the carbon dioxide discharged through the auxiliary flue gas channel 20 from re-entering the industrial silicon thermal furnace, prevent the discharged carbon dioxide from polluting the smelting of industrial silicon, and avoid the discharged carbon dioxide from interfering with the waste heat boiler 12, SCR denitrification device 13 and negative pressure bag dust collector 14 on the main flue gas channel 10.

[0031] In one embodiment, a first fan 18 is disposed on the smoke return pipe 15 , and a second fan 21 is disposed on the secondary smoke channel 20 .

[0032] It can be understood that the first fan 18 can suck the flue gas flowing out of the negative pressure bag filter 14 into the flue gas return pipe 15, helping the purified flue gas to flow back into the industrial silicon thermal furnace, and the second fan 21 can suck the flue gas flowing out of the negative pressure bag filter 14 into the auxiliary flue gas channel 20, helping the purified flue gas to be discharged into the atmosphere. By adjusting the power of the first fan 18 and the second fan 21, the flow in the flue gas return pipe 15 and the auxiliary flue gas channel 20 can be adjusted to adjust the distribution of the flue gas flowing out of the negative pressure bag filter 14, thereby controlling the distribution ratio of the reflux amount and the external discharge amount of the flue gas. In addition, the setting of the first fan 18 and the second fan 21 can increase the flow rate of the flue gas in the flue gas purification system of the industrial silicon thermal furnace, ensuring smooth flow of the flue gas.

[0033] In one embodiment, a first flow sensor is disposed in the smoke return pipe 15 and is disposed away from the first fan 18 , and a second flow sensor is disposed in the auxiliary smoke channel 20 and is disposed away from the second fan 21 .

[0034] Furthermore, by setting the first flow sensor and the second flow sensor to respectively measure the smoke flow in the smoke return pipe 15 and the auxiliary smoke channel 20 in real time, the distribution ratio of the smoke return volume and the external discharge volume can be accurately obtained, so as to automatically control the power of the first fan 18 and the second fan 21 through the external controller, thereby adjusting the smoke return volume and the external discharge volume in real time. The first flow sensor is set away from the first fan 18, which can reduce the interference of the first fan 18 on the first flow sensor, and the second flow sensor is set away from the second fan 21, which can reduce the interference of the second fan 21 on the second flow sensor, so as to obtain more accurate flow measurement results.

[0035] In one embodiment, a chimney 22 is provided at the second end of the secondary flue gas channel 20, and a discharge port is opened in the chimney 22. A wet desulfurization device is provided on the secondary flue gas channel 20, and the wet desulfurization device is located between the first end and the second end.

[0036] It can be explained that the flue gas needs to be desulfurized before being discharged through the chimney 22. By setting up a wet desulfurization device to desulfurize the flue gas, compared with the dry desulfurization commonly used in the existing industrial silicon thermal furnace flue gas treatment process, the wet desulfurization has a higher desulfurization efficiency and can quickly desulfurize and purify a large amount of flue gas, thereby improving the flue gas purification effect. It can be further explained that the flue gas of multiple industrial silicon thermal furnaces can share the same wet desulfurization device and be discharged through the same chimney 22.

[0037] In one embodiment, a cyclone dust collector 16 is further provided on the main flue gas channel 10, and the cyclone dust collector 16 is located between the waste heat boiler 12 and the SCR denitrification device 13. Figure 1 The cyclone dust collector 16 is arranged after the waste heat boiler 12. After the waste heat boiler 12 precipitates the larger particles in the flue gas, the flue gas flows into the cyclone dust collector 16. The larger particles are further removed by the cyclone dust collector 16, thereby reducing the pollution of the particles to the SCR denitrification device 13 and further improving the dust removal effect of the industrial silicon thermal furnace flue gas purification system.

[0038] In one embodiment, the length of the smoke return pipe 15 is less than 45 m.

[0039] It should be noted that, in one embodiment, the flue gas data generated by the industrial silicon thermal furnace are: temperature 400℃-800℃, flue gas volume 220000Nm 3 / h, particle (microsilica powder) content is about 4g / Nm 3 , sulfur dioxide content 200mg / Nm 3 、Nitrogen oxide content is about 200mg / Nm 3 After the flue gas passes through the waste heat boiler 12, the temperature of the flue gas flowing out of the waste heat boiler 12 is about 230°C, the temperature of the flue gas flowing out of the SCR denitration device 13 is about 220°C, and the temperature of the flue gas flowing out of the negative pressure bag filter 14 is about 200°C. By placing the negative pressure bag filter 14 close to the industrial silicon thermal furnace, the length of the flue gas return pipe 15 is less than 45m, which can reduce the heat loss of the flue gas in the flue gas return pipe 15 and improve the waste heat utilization efficiency.

[0040] In one embodiment, the waste heat boiler 12 is provided with an adsorption device for adsorbing solid particles. It can be understood that by integrating the adsorption device in the waste heat boiler 12, solid particles in the flue gas can be more effectively captured, thereby improving the overall dust removal efficiency.

[0041] In one embodiment, the discharge port is connected to a carbon dioxide recovery device. Since the carbon dioxide in the flue gas is concentrated at the diversion port 17 and discharged to the atmosphere through the secondary flue gas channel 20, by discharging the carbon dioxide to the carbon dioxide recovery device, the emission of carbon dioxide can be significantly reduced, which is conducive to the recycling of resources and makes the industrial silicon thermal furnace flue gas purification system more environmentally friendly.

[0042] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An industrial silicon thermal furnace flue gas purification system, characterized in that: The industrial silicon thermal furnace is provided with an input port and an output port, and the industrial silicon thermal furnace fume purification system comprises: A main flue gas channel, wherein the main flue gas channel is provided with a flue gas outlet pipe, a waste heat boiler, an SCR denitration device, a negative pressure bag filter and a flue gas return pipe in sequence along the flow direction of the flue gas, the flue gas outlet pipe and the flue gas return pipe are respectively connected to the output port and the input port, and a diversion port is opened on the main flue gas channel, and the diversion port is located between the negative pressure bag filter and the flue gas return pipe; A secondary smoke channel, wherein a first end of the secondary smoke channel is connected to the diversion port, and a discharge port is provided at a second end of the secondary smoke channel.

2. The industrial silicon thermal furnace flue gas purification system according to claim 1, characterized in that: The main flue gas channel includes a first channel, a second channel and a third channel, and the first channel, the second channel and the third channel are connected in sequence along the flow direction of the flue gas to form an n-type structure, an end of the first channel away from the second channel is connected to the output port, an end of the third channel away from the second channel is connected to the input port, the diversion port is opened on the third channel, the waste heat boiler and the negative pressure bag dust collector are respectively arranged on the first channel and the third channel, and the waste heat boiler and the negative pressure bag dust collector are both arranged along the flow direction of the flue gas.

3. The industrial silicon thermal furnace flue gas purification system according to claim 2, characterized in that: The diversion port is opened on a side of the third channel away from the first channel, and the secondary smoke channel extends in a direction away from the first channel.

4. The industrial silicon thermal furnace flue gas purification system according to claim 1, characterized in that: The smoke return pipe is provided with a first fan, and the auxiliary smoke channel is provided with a second fan.

5. The industrial silicon thermal furnace fume purification system according to claim 4, characterized in that: A first flow sensor is arranged in the smoke return pipe, and the first flow sensor is arranged away from the first fan. A second flow sensor is arranged in the auxiliary smoke channel, and the second flow sensor is arranged away from the second fan.

6. The industrial silicon thermal furnace flue gas purification system according to any one of claims 1 to 5, characterized in that: The second end of the secondary flue gas channel is provided with a chimney, the chimney is provided with the discharge port, and the secondary flue gas channel is provided with a wet desulfurization device, the wet desulfurization device is located between the first end and the second end.

7. The industrial silicon thermal furnace fume purification system according to any one of claims 1 to 5, characterized in that: A cyclone dust collector is also provided on the main flue gas channel, and the cyclone dust collector is located between the waste heat boiler and the SCR denitration device.

8. The industrial silicon thermal furnace fume purification system according to any one of claims 1 to 5, characterized in that: The length of the smoke return pipe is less than 45m.

9. The industrial silicon thermal furnace fume purification system according to any one of claims 1 to 5, characterized in that: The waste heat boiler is provided with an adsorption device for adsorbing solid particles.

10. The industrial silicon thermal furnace flue gas purification system according to any one of claims 1 to 5, characterized in that: The discharge port is connected to a carbon dioxide recovery device.

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