Flue gas volatilization circulating system and tunnel kiln

Abstract

The utility model discloses a flue gas volatilization circulation system and a tunnel kiln, which belong to the technical field of flue gas treatment in the kiln, the flue gas volatilization circulation system comprises a preheating section, a sintering section and a smoke exhaust assembly, the preheating section is connected with the sintering section, the smoke exhaust assembly is communicated with the preheating section, and the flue gas volatilization circulation system further comprises a flue gas circulation assembly, one end of the flue gas circulation assembly is communicated with the preheating section, the other end of the flue gas circulation assembly is communicated with the sintering section, one end of the flue gas circulation assembly is communicated with the smoke exhaust assembly, and the smoke exhaust assembly exhausts low-temperature flue gas generated in the preheating section outwards; and the circulating fan is used for feeding high-temperature volatile matter mixed flue gas into the sintering section for combustion, so that the energy consumption of sintering materials in the kiln is reduced, and the pollution caused by outward emission of the flue gas is reduced.

Description

Technical Field

[0001] This utility model relates to the field of kiln flue gas treatment technology, specifically to a flue gas volatilization and circulation system and a tunnel kiln. Background Technology

[0002] The exhaust gas duct of a tunnel kiln is typically located at the kiln entrance. High-temperature flue gas is drawn into the exhaust duct by an exhaust fan and then discharged outside the kiln. During the sintering of lithium-ion battery anode materials, the materials contain a large amount of volatile components such as asphalt. These volatile components volatilize at 300℃-1000℃ and can burn when exposed to an open flame above 620℃, thus serving as fuel. Currently, some kilns do not treat the volatile components in their flue gas, directly discharging it outdoors, leading to increased gas consumption and environmental pollution. Furthermore, some kilns have flue gas recirculation structures, but the recirculated flue gas is not separated, resulting in low utilization. Since the flue gas inside the kiln is mixed, and the 300℃-1000℃ flue gas contains combustible volatile substances, direct discharge outdoors wastes energy. On the other hand, a high volatile content in the exhaust duct can ignite the duct when exposed to an open flame, easily causing safety accidents.

[0003] A patent application with publication number CN106766877A discloses an environmentally friendly circulating treatment system for tunnel kiln flue gas, including a tunnel roasting kiln. The tunnel roasting kiln is sequentially equipped with a preheating section, a roasting section, a heat preservation section, and a cooling section. The preheating section is connected to an exhaust fan, which is connected to a desulfurization, denitrification, and dust removal system through an exhaust duct. A waste heat utilization system is installed at the front end of the preheating section, a balancing fan is installed in the middle section, and a dehumidification duct is installed at the rear end. One end of the balancing duct is connected to the balancing fan, and the other end is connected to a heat supply fan. Both the drying duct and the heat supply duct are located in a tunnel-type drying chamber. The tunnel-type drying chamber is connected to a dehydration device through a dehydration duct, and the dehydration device is connected to a dehumidification and air supply fan through a duct. The dehumidification and air supply fan is connected to the cooling section of the tunnel roasting kiln through a dehumidification duct. This environmentally friendly circulating treatment system for tunnel kiln flue gas does not perform combustion treatment on the waste gas, resulting in low energy utilization and dangerous emissions. Utility Model Content

[0004] One of the objectives of this invention is to provide a flue gas volatilization and circulation system that solves the problems of dangerous flue gas and low energy utilization rate of existing flue gas treatment systems.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0006] A flue gas volatilization and circulation system includes a preheating section, a firing section, and a flue gas exhaust assembly. The preheating section is connected to the firing section, and the flue gas exhaust assembly is connected to the preheating section. The system also includes a flue gas circulation assembly, one end of which is connected to the preheating section, and the other end of which is connected to the firing section. The flue gas exhaust assembly discharges the low-temperature flue gas generated in the preheating section. A circulating fan sends a high-temperature volatile mixture of flue gas into the firing section for combustion, thereby reducing the energy consumption of the sintered materials in the kiln and minimizing pollution caused by flue gas emissions.

[0007] Furthermore, the smoke exhaust assembly includes a first smoke exhaust pipe, a second smoke exhaust pipe, a first valve, and a smoke exhaust fan. One end of the first smoke exhaust pipe and one end of the second smoke exhaust pipe are both connected to the preheating section. The first valve is installed on the first smoke exhaust pipe. The other end of the first smoke exhaust pipe and the other end of the second smoke exhaust pipe are both connected to one end of the smoke exhaust fan. The other end of the smoke exhaust fan is connected to the outside and is used to extract smoke and control the amount of smoke extracted.

[0008] Preferably, the smoke exhaust assembly further includes a side exhaust port, which is located below one end of the second smoke exhaust pipe and is used for lateral ventilation.

[0009] Furthermore, the flue gas recirculation assembly includes a flue gas inlet pipe, a flue gas inlet valve, a recirculating fan, a flue gas delivery pipe, and a second valve. One end of the flue gas inlet pipe is connected to the firing section, and the other end of the flue gas inlet pipe is connected to one end of the recirculating fan and one end of the exhaust fan, respectively. Both ends of the flue gas delivery pipe are connected to the other end of the recirculating fan and the firing section, respectively. The second valve is disposed between the exhaust fan and the flue gas inlet pipe. The flue gas inlet valve is disposed near one end of the flue gas inlet pipe and is used to actively draw in the mixed flue gas from the preheating section and send it to the firing section for combustion.

[0010] Furthermore, the flue gas recirculation assembly also includes a third valve, which is positioned between one end of the recirculation fan and the external environment, and is used to discharge flue gas to the outside.

[0011] Preferably, the flue gas recirculation assembly further includes a temperature sensor and a fourth valve. Both the fourth valve and the temperature sensor are installed on the flue gas supply pipe to detect the temperature of the flue gas fed into the preheating section, preventing low-temperature flue gas from entering and affecting the material calcination reaction.

[0012] Preferably, the flue gas recirculation assembly further includes a fifth valve, which is disposed between the flue gas supply pipe and the firing section, and is used to control the amount of flue gas entering.

[0013] As an even better feature, the flue pipe is provided with an ignition nozzle at one end of the firing section for directly igniting the volatile flue gas, thereby improving the utilization rate of the flue gas.

[0014] Even better, it also includes a cooling section connected to the firing section, used to cool the firing material and accelerate the firing efficiency.

[0015] The second objective of this utility model is to provide a tunnel kiln that solves the problem of low flue gas utilization rate in existing tunnel kilns.

[0016] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0017] A tunnel kiln includes the aforementioned flue gas volatilization and circulation system, which utilizes the volatile flue gas inside the kiln to reduce energy consumption and environmental pollution.

[0018] The beneficial effects of this utility model are as follows:

[0019] (1) The flue gas volatile circulation system is equipped with a smoke exhaust component and a flue gas circulation component. The smoke exhaust component is connected to the preheating section and can exhaust the flue gas generated during the preheating of materials. The flue gas circulation component is connected to the preheating section and the firing section respectively. It can introduce the volatiles generated in the preheating section into the firing section for combustion and utilization, eliminate combustible volatiles in the flue gas, and reduce the pollution caused by direct discharge to the environment. The air inlet of the flue gas circulation component is connected to the smoke exhaust component and can introduce high-temperature volatiles into the firing section. At low temperature, the flue gas is directly discharged to ensure the stability of flue gas combustion.

[0020] (2) The exhaust component of the flue gas volatilization circulation system includes a side exhaust port, which can collect air from the side to increase the air intake. The flue gas circulation component is equipped with a circulation fan and a temperature sensor for actively drawing in flue gas. The temperature sensor is used to detect the temperature of the flue gas introduced into the firing section to prevent low-temperature flue gas from entering and affecting the firing of the material. Attached Figure Description

[0021] Figure 1 A layout diagram of the flue gas volatilization circulation system provided by this utility model.

[0022] Figure label:

[0023] 1. Preheating section; 2. Firing section; 3. Smoke exhaust assembly; 31. First valve; 32. First smoke exhaust pipe; 33. Second smoke exhaust pipe; 331. Side exhaust vent; 34. Smoke exhaust fan; 4. Smoke circulation assembly; 41. Smoke inlet pipe; 42. Smoke inlet valve; 43. Second valve; 44. Third valve; 45. Circulation fan; 46. Temperature sensor; 47. Fourth valve; 48. Smoke supply pipe; 49. Fifth valve; 491. Ignition nozzle; 5. Inlet replacement chamber; 6. Conveyor vehicle; 7. Outlet replacement chamber; 8. Cooling section. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment discloses a flue gas volatilization and circulation system, including a preheating section 1, a firing section 2, and a flue gas exhaust assembly 3. The preheating section 1 is connected to the firing section 2, and the flue gas exhaust assembly 3 is connected to the preheating section 1. It also includes a flue gas circulation assembly 4, one end of which is connected to the preheating section 1, and the other end of which is connected to the firing section 2. The flue gas circulation assembly 4 is also connected to the flue gas exhaust assembly 3. The flue gas exhaust assembly 3 can extract and discharge the flue gas generated by heating in the preheating section 1, and can also send high-temperature volatiles into the flue gas circulation assembly 4. The flue gas circulation assembly 4 sends the volatiles to the firing section 2, where the volatiles burn to generate heat, thereby reducing the energy consumption of the kiln sintering and reducing environmental pollution.

[0027] Furthermore, the smoke exhaust assembly 3 includes a first smoke exhaust pipe 32, a second smoke exhaust pipe 33, a first valve 31, and a smoke exhaust fan 34. One end of the first smoke exhaust pipe 32 and one end of the second smoke exhaust pipe 33 are both connected to the preheating section 1. The first valve 31 is installed on the first smoke exhaust pipe 32 to control the opening and closing of the first smoke exhaust pipe 32. The other end of the first smoke exhaust pipe 32 and the other end of the second smoke exhaust pipe 33 are both connected to one end of the smoke exhaust fan 34. The other end of the smoke exhaust fan 34 is connected to the outside, which can directly discharge the flue gas to the outside. The first smoke exhaust pipe 32 can increase the circulation volume of the flue gas when a large amount of volatiles are generated after the preheating section 1 is heated.

[0028] Preferably, the smoke exhaust assembly 3 further includes a side exhaust port 331, which is located below one end of the second smoke exhaust pipe 33. The side exhaust port 331 is used for lateral air intake to increase the air intake volume.

[0029] Furthermore, the flue gas recirculation assembly 4 includes a flue gas inlet pipe 41, a flue gas inlet valve 42, a recirculating fan 45, a flue gas supply pipe 48, and a second valve 43. One end of the flue gas inlet pipe 41 is connected to the firing section 2, and the other end of the flue gas inlet pipe 41 is connected to one end of the recirculating fan 45 and the exhaust fan 34, respectively, so as to supply smoke to the recirculating fan 45 and the exhaust fan 34, and facilitate the external and recirculated exhaust of smoke. The two ends of the flue gas supply pipe 48 are connected to the other end of the recirculating fan 45 and the firing section 2, respectively. The second valve 43 is set between the exhaust fan 34 and the flue gas inlet pipe 41 and is used to control the amount of flue gas drawn from the preheating section 1. The flue gas inlet valve 42 is set at one end near the flue gas inlet pipe 41 and is used to control the amount of smoke inlet. The recirculating fan 45 is used to provide the suction power for active smoke extraction.

[0030] Furthermore, the flue gas recirculation assembly 4 also includes a third valve 44, which is located between one end of the circulating fan 45 and the external environment. The third valve 44 is used to control the circulating fan 45 to directly discharge the inhaled flue gas to the outside, thereby serving as a flue gas screening and diversion function to prevent low-temperature flue gas from entering the firing section 2.

[0031] Furthermore, the flue gas recirculation assembly 4 also includes a temperature sensor 46 and a fourth valve 47. Both the fourth valve 47 and the temperature sensor 46 are installed on the flue gas supply pipe 48. The temperature sensor 46 is used to detect the temperature of the flue gas input to the firing section 2. Both the temperature sensor 46 and the valve are connected to the PLC. After the temperature of the flue gas is detected to be up to standard, the fourth valve 47 is controlled to open to prevent low-temperature flue gas from entering the firing section 2 and affecting the firing of the material. This ensures that the temperature in the firing section 2 is within the set range to meet the requirements of the material firing reaction.

[0032] Preferably, the flue gas recirculation assembly 4 further includes a fifth valve 49, which is disposed between the flue gas supply pipe 48 and the firing section 2. The fifth valve 49 is used to control the amount of volatile flue gas input into the firing section 2 and to control the temperature in the firing section 2 within a set range.

[0033] More preferably, an ignition nozzle 491 is provided at one end of the flue pipe 48 in the firing section 2. The ignition nozzle 491 is used to directly ignite the volatile flue gas supplied by the flue gas circulation assembly 4, thereby improving the combustion degree of the flue gas.

[0034] More preferably, it also includes a cooling section 8, which is connected to the firing section 2. The cooling section 8 is used to cool the fired material. The cooling section 8 is equipped with a cooling fan to introduce cold air to accelerate the cooling of the material and improve the efficiency of firing the material.

[0035] The working process of this flue gas volatilization recirculation system is as follows:

[0036] The material is sent to the preheating section 1, where the temperature gradually rises to generate flue gas. The exhaust fan 34 starts to draw the flue gas out of the preheating section 1 and discharge it outward. After the temperature of the preheating section 1 rises to a certain level, the asphalt in the material produces volatiles. The exhaust fan 34 is turned off, and the circulating fan 45 and the second valve 43 are opened. The volatile mixed flue gas is sent into the firing section 2 through the flue gas supply pipe 48. The firing section 2 ignites the mixed flue gas for combustion. After the temperature sensor 46 detects that the temperature of the inhaled flue gas has dropped below the set value, the fourth valve 47 is closed and the third valve 44 is opened to stop the flue gas input and discharge the flue gas outward.

[0037] Example 2

[0038] This embodiment also discloses a tunnel kiln, including a flue gas volatilization and circulation system, an inlet replacement chamber 5, an outlet replacement chamber 7, and a conveyor 6. The inlet replacement chamber 5 is connected to the preheating section 1, and the outlet replacement chamber 7 is connected to the cooling section 8. The outlet replacement chamber 7 and the inlet replacement chamber 7 are used to exhaust air when materials enter and exit the kiln, and the conveyor 6 is used to transfer materials into the kiln.

[0039] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and any modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A flue gas volatilization circulation system, comprising a preheating section (1), a firing section (2), and a flue gas exhaust assembly (3), wherein the preheating section (1) is connected to the firing section (2), and the flue gas exhaust assembly (3) is connected to the preheating section (1), characterized in that: It also includes a flue gas recirculation component (4), one end of which is connected to the preheating section (1), the other end of which is connected to the firing section (2), and one end of which is connected to the exhaust component (3). The smoke exhaust assembly (3) includes a first smoke exhaust pipe (32), a second smoke exhaust pipe (33), a first valve (31), and a smoke exhaust fan (34). One end of the first smoke exhaust pipe (32) and one end of the second smoke exhaust pipe (33) are both connected to the preheating section (1). The first valve (31) is installed on the first smoke exhaust pipe (32). The other end of the first smoke exhaust pipe (32) and the other end of the second smoke exhaust pipe (33) are both connected to one end of the smoke exhaust fan (34). The other end of the smoke exhaust fan (34) is connected to the outside. The flue gas circulation assembly (4) includes a flue gas inlet pipe (41), a flue gas inlet valve (42), a circulating fan (45), a flue gas delivery pipe (48), and a second valve (43). One end of the flue gas inlet pipe (41) is connected to the firing section (2), and the other end of the flue gas inlet pipe (41) is connected to one end of the circulating fan (45) and the exhaust fan (34), respectively. Both ends of the flue gas delivery pipe (48) are connected to the other end of the circulating fan (45) and the firing section (2), respectively. The second valve (43) is located between the exhaust fan (34) and the flue gas inlet pipe (41), and the flue gas inlet valve (42) is located near one end of the flue gas inlet pipe (41).

2. The flue gas volatilization and recirculation system according to claim 1, characterized in that: The smoke exhaust assembly (3) also includes a side exhaust port (331), which is located below one end of the second smoke exhaust pipe (33).

3. The flue gas volatilization and recirculation system according to claim 1, characterized in that: The flue gas recirculation assembly (4) also includes a third valve (44), which is located between one end of the recirculation fan (45) and the external environment.

4. The flue gas volatilization and recirculation system according to claim 3, characterized in that: The flue gas recirculation assembly (4) also includes a temperature sensor (46) and a fourth valve (47), both of which are mounted on the flue gas supply pipe (48).

5. The flue gas volatilization and recirculation system according to claim 4, characterized in that: The flue gas recirculation assembly (4) also includes a fifth valve (49), which is disposed between the flue gas supply pipe (48) and the firing section (2).

6. The flue gas volatilization and recirculation system according to claim 5, characterized in that: The flue pipe (48) is equipped with an ignition nozzle (491) at one end of the firing section (2).

7. The flue gas volatilization and recirculation system according to claim 1, characterized in that: It also includes a cooling section (8) connected to the firing section (2).

8. A tunnel kiln, characterized in that, Includes the flue gas volatilization and circulation system according to any one of claims 1-7.

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