Flue gas waste heat recovery treatment system for ceramic factory

Abstract

The utility model relates to the technical field of waste heat recovery, in particular to a ceramic factory flue gas waste heat recovery treatment system which comprises a kiln smoke exhaust system, a flue gas waste heat recovery system and a flue gas treatment system. The flue gas waste heat recovery system is communicated with the kiln smoke exhaust system and the flue gas treatment system; the flue gas waste heat recovery system comprises a primary heat exchanger, a secondary heat exchanger, a hot blast stove, a drying kiln and a heating fan; the two ends of a hot medium channel of the first-stage heat exchanger communicate with the second-stage heat exchanger and a kiln smoke exhaust system correspondingly, and the two ends of a cold medium channel of the first-stage heat exchanger communicate with a heating fan and a drying kiln correspondingly. The two ends of a hot medium channel of the second-stage heat exchanger communicate with the first-stage heat exchanger and the flue gas treatment system correspondingly, and the two ends of a cold medium channel of the second-stage heat exchanger communicate with the hot blast stove and the drying kiln correspondingly. The hot-blast stove is communicated with the flue gas treatment system. Through the structural design above, heat energy in smoke exhausted by the smoke exhaust system of the kiln is effectively recycled.

Description

[0001] Priority Statement

[0002] This application claims priority to Chinese Patent Application No. CN2024220909069, filed on August 28, 2024, entitled "A Waste Heat Recovery System for Flue Gas in a Ceramic Factory", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This utility model relates to the field of waste heat recovery technology, and in particular to a waste heat recovery and treatment system for flue gas from a ceramics factory. Background Technology

[0004] Currently, many ceramic factories, when dealing with flue gas generated from kilns, mainly focus on removing pollutants to meet environmental emission standards before discharging it into the atmosphere through chimneys. Traditional ceramic factories do not effectively recover and utilize the heat energy from the flue gas; instead, they allow the heat to dissipate directly. This not only results in significant energy waste and increases operating costs for the enterprises but also hinders the achievement of energy conservation, emission reduction, and environmental protection goals.

[0005] Subsequently, technologies for industrial flue gas treatment emerged. For example, Chinese patent document CN102120143A discloses a method and apparatus for sulfur recovery and waste heat utilization in high-temperature flue gas. High-temperature flue gas containing elemental sulfur (at temperatures above 444°C) after a reduction reaction is passed through this equipment. The high-temperature flue gas containing elemental sulfur flows outside the heat exchange tubes (plates), while the cooling medium flows inside. The gaseous sulfur in the flue gas condenses into liquid elemental sulfur on the outer wall of the heat exchange tubes. The liquid elemental sulfur flows down the outer wall of the heat exchange tubes to a collection funnel at the bottom of the heat exchanger, and is collected in the sulfur outlet pipe for recovery. The desulfurized high-temperature flue gas still maintains a temperature above 300°C, which can be reused as clean flue gas for waste heat recovery. Although the above-mentioned existing technologies recover sulfur and utilize waste heat from flue gas, the waste heat utilization rate needs to be improved.

[0006] Therefore, it is necessary to improve existing technologies to solve the above problems. Utility Model Content

[0007] The purpose of this utility model is to provide a waste heat recovery system for flue gas in ceramic factories, which aims to solve the problem in the prior art where the heat energy of kiln flue gas is directly dissipated after treatment without being recovered and utilized.

[0008] To achieve the above objectives, this utility model provides a waste heat recovery system for ceramic factory flue gas, including a kiln exhaust system, a waste heat recovery system, and a flue gas treatment system; the waste heat recovery system is connected to the kiln exhaust system and the flue gas treatment system; the waste heat recovery system is used to recover and utilize the heat energy in the flue gas discharged from the kiln exhaust system, and the flue gas treatment system is used to treat the flue gas discharged from the kiln exhaust system and the waste heat recovery system before discharging it;

[0009] The flue gas waste heat recovery system includes a primary heat exchanger, a secondary heat exchanger, a hot blast stove, a drying kiln, and a heating fan. The two ends of the hotter medium channel of the primary heat exchanger are connected to the secondary heat exchanger and the kiln exhaust system, respectively, and the two ends of the colder medium channel of the primary heat exchanger are connected to the heating fan and the drying kiln, respectively. The two ends of the hotter medium channel of the secondary heat exchanger are connected to the primary heat exchanger and the flue gas treatment system, respectively, and the two ends of the colder medium channel of the secondary heat exchanger are connected to the hot blast stove and the drying kiln, respectively. The hot blast stove is connected to the flue gas treatment system.

[0010] Furthermore, a first valve is installed between the primary heat exchanger and the secondary heat exchanger, a second valve is installed between the secondary heat exchanger and the flue gas treatment system, and a pipeline is connected between the primary heat exchanger and the first valve, which connects to the second valve and the flue gas treatment system, and a third valve is installed on the pipeline.

[0011] Furthermore, a dehumidifying fan is installed between the secondary heat exchanger and the drying kiln.

[0012] Furthermore, the hot air furnace is equipped with a burner; a combustion-supporting fan is installed between the burner and the secondary heat exchanger, and the combustion-supporting fan is connected to the secondary heat exchanger through a fourth valve. The burner is also connected to a natural gas pipeline.

[0013] Furthermore, the combustion fan is also connected to a natural air duct via a fifth valve.

[0014] Furthermore, the hot blast stove is also equipped with a cold air outlet, which is connected to the secondary heat exchanger through a sixth valve.

[0015] Furthermore, the air vent is also connected to a natural air duct via a seventh valve.

[0016] Furthermore, the flue gas treatment system includes a cyclone dust collector, a spray drying tower, a bag filter, a semi-dry desulfurization and dust removal system, and a centralized emission chimney; the flue gas discharged from the hot blast stove passes through the cyclone dust collector, the spray drying tower, and the bag filter in sequence, and finally enters the centralized emission chimney for external discharge; the flue gas discharged from the kiln exhaust system passes through the primary heat exchanger, the secondary heat exchanger, and the semi-dry desulfurization and dust removal system in sequence, and finally enters the centralized emission chimney for external discharge.

[0017] Furthermore, the kiln exhaust system includes a primary exhaust device and a secondary exhaust device; both the primary and secondary exhaust devices are connected to the primary heat exchanger.

[0018] The waste heat recovery system for ceramic factory flue gas provided by this utility model, compared with the prior art, involves heat exchange between the flue gas discharged from the kiln exhaust system and the hot air delivered by the heating fan in a primary heat exchanger. The heat energy in the flue gas discharged from the kiln exhaust system is transferred to the hot air delivered by the heating fan, causing the temperature of the hot air to continue to rise. This hot air then acts on the drying kiln, thereby reducing the heating load and energy consumption of the heating fan and effectively recovering and utilizing the heat energy in the flue gas discharged from the kiln exhaust system. The flue gas discharged from the kiln exhaust system then exchanges heat again with the flue gas discharged from the drying kiln in a secondary heat exchanger. The heat energy in the flue gas discharged from the kiln exhaust system is transferred to the flue gas discharged from the drying kiln, causing the temperature of the flue gas discharged from the drying kiln to rise. This flue gas is then sent to the hot blast stove as combustion air, thus effectively recovering and utilizing the heat energy in the flue gas discharged from the kiln exhaust system again. At the same time, it can provide heat to the inlet of the hot blast stove (reducing the fuel consumption of the hot blast stove when the combustion air temperature is high) and / or cool the flue gas discharged from the hot blast stove. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the flue gas waste heat recovery system.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Kiln exhaust system; 11. Primary exhaust system for kilns; 12. Secondary exhaust system for kilns;

[0023] 2. Flue gas waste heat recovery system; 21. Primary heat exchanger; 22. Secondary heat exchanger; 23. Hot air furnace; 231. Burner; 232. Combustion fan; 233. Cold air outlet; 24. Drying kiln; 25. Heating fan; 26. Dehumidifying fan; 271. First valve; 272. Second valve; 273. Third valve; 274. Fourth valve; 275. Fifth valve; 276. Sixth valve; 277. Seventh valve;

[0024] 3. Flue gas treatment system; 31. Cyclone dust collector; 32. Spray drying tower; 33. Bag filter dust collector; 34. Semi-dry desulfurization and dust removal system; 35. Centralized emission chimney. Detailed Implementation

[0025] The present invention will be described in detail below with reference to specific embodiments.

[0026] In this utility model, unless otherwise explicitly specified and limited, when terms such as "set in," "connected," or "linked" appear, these terms should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through one or more intermediate media. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The directional terms appearing in this utility model are for the purpose of better describing the characteristics of the features and the relationships between them. It should be understood that when the placement direction of this utility model changes, the direction of the characteristics of the features and the relationships between them also changes accordingly. Therefore, directional terms do not constitute an absolute limitation on the characteristics of the features and the relationships between them in space, but only a relative limitation.

[0027] This utility model provides a waste heat recovery and treatment system for flue gas in ceramic factories, such as... Figures 1 to 2 As shown, it includes a kiln exhaust system 1, a flue gas waste heat recovery system 2, and a flue gas treatment system 3; the flue gas waste heat recovery system 2 is connected to the kiln exhaust system 1 and the flue gas treatment system 3; the flue gas waste heat recovery system 2 is used to recover and utilize the heat energy in the flue gas discharged from the kiln exhaust system 1, and the flue gas treatment system 3 is used to treat the flue gas discharged from the kiln exhaust system 1 and the flue gas waste heat recovery system 2 before discharging it;

[0028] The flue gas waste heat recovery system 2 includes a primary heat exchanger 21, a secondary heat exchanger 22, a hot blast stove 23, a drying kiln 24, and a heating fan 25. The two ends of the hotter medium channel of the primary heat exchanger 21 are connected to the secondary heat exchanger 22 and the kiln exhaust system 1, respectively, and the two ends of the colder medium channel of the primary heat exchanger 21 are connected to the heating fan 25 and the drying kiln 24, respectively. The two ends of the hotter medium channel of the secondary heat exchanger 22 are connected to the primary heat exchanger 21 and the flue gas treatment system 3, respectively, and the two ends of the colder medium channel of the secondary heat exchanger 22 are connected to the hot blast stove 23 and the drying kiln 24, respectively. The hot blast stove 23 is connected to the flue gas treatment system 3.

[0029] Based on the above structural configuration, the flue gas discharged through the kiln exhaust system 1 exchanges heat with the hot air delivered by the heating fan 25 in the primary heat exchanger 21. The heat energy in the flue gas discharged through the kiln exhaust system 1 is transferred to the hot air delivered by the heating fan 25, causing the temperature of the hot air to continue to rise. This heat energy then acts on the drying kiln 24, thereby reducing the heating load and energy consumption of the heating fan 25 and effectively recovering and utilizing the heat energy in the flue gas discharged through the kiln exhaust system 1. The flue gas discharged through the kiln exhaust system 1 then exchanges heat again with the flue gas discharged from the drying kiln 24 in the secondary heat exchanger 22. The heat energy of the flue gas discharged from the exhaust system 1 is transferred to the flue gas discharged from the drying kiln 24, raising the temperature of the flue gas discharged from the drying kiln 24. Subsequently, it is sent to the hot blast stove 23 as combustion air, thereby effectively recovering and utilizing the heat energy in the flue gas discharged from the kiln exhaust system 1. At the same time, it can provide heat to the inlet of the hot blast stove 23 (which can reduce the fuel consumed by the hot blast stove 23 when the combustion air temperature is high) and / or cool the flue gas discharged from the hot blast stove 23. Finally, the flue gas discharged from the hot blast stove 23 and the flue gas discharged from the kiln exhaust system 1 enter the flue gas treatment system 3 for treatment before being discharged.

[0030] In this embodiment, a first valve 271 is provided between the primary heat exchanger 21 and the secondary heat exchanger 22, and a second valve 272 is provided between the secondary heat exchanger 22 and the flue gas treatment system 3. A pipe is connected to the first valve 271 of the primary heat exchanger 21, which connects to the second valve 272 and the flue gas treatment system 3. A third valve 273 is provided on this pipe. The bypass pipe ensures that if the secondary heat exchanger 22 malfunctions, another pipe can be used to ensure the system can continue to operate and guarantee the stability of the overall system. Simultaneously, if it is necessary to cool the flue gas discharged from the drying kiln 24 to the flue gas discharged from the hot blast stove 23, the flue gas discharged from the kiln exhaust system 1 will not pass through the secondary heat exchanger 22. This prevents the flue gas discharged from the drying kiln 24 from being further heated by the secondary heat exchanger 22, thus ensuring that the flue gas temperature reaching the cooling air outlet 233 (described below) is not too high, better meeting the cooling requirements.

[0031] In this embodiment, a dehumidifying fan 26 is provided between the secondary heat exchanger 22 and the drying kiln 24. By reducing the humidity inside the drying kiln 24, the dehumidifying fan 26 indirectly improves the efficiency of heat exchange and further reduces energy consumption.

[0032] In this embodiment, the hot blast stove 23 is equipped with a burner 231; a combustion-supporting fan 232 is installed between the burner 231 and the secondary heat exchanger 22, and the combustion-supporting fan 232 is connected to the secondary heat exchanger 22 through a fourth valve 274. The burner 231 is connected to a natural gas pipeline. When the drying kiln 24 is operating normally, the flue gas discharged from the drying kiln 24 can act on the burner 231 through the fourth valve 274, reducing the consumption of natural gas.

[0033] In this embodiment, the combustion fan 232 is connected to a natural air duct via a fifth valve 275. When the drying kiln 24 is not in operation, the natural air duct can be connected via the fifth valve 275 to ensure sufficient combustion air for the system and to ensure normal operation.

[0034] In this embodiment, the hot blast furnace 23 is also provided with a cooling air inlet 233, which is connected to the secondary heat exchanger 22 via a sixth valve 276. When the drying kiln 24 is operating normally, the flue gas discharged from the drying kiln 24 can be directed through the sixth valve 276 to act on the cooling air inlet 233 to cool the flue gas discharged from the hot blast furnace 23, while simultaneously sending the flue gas discharged from the drying kiln 24 to the flue gas treatment system 3.

[0035] In this embodiment, the cooling air outlet 233 is also connected to a natural air duct via a seventh valve 277. When the drying kiln 24 is not in operation, the natural air duct can be connected via the seventh valve 277, and the cooler natural air can be sent into the cooling air outlet 233 to reduce the temperature of the flue gas discharged from the hot blast furnace 23, thereby ensuring the normal operation of the system.

[0036] Through the structural design above and the control of valves, the flue gas discharged from the drying kiln 24 can be used as the combustion air for the burner 231 or as the cooling air for the cold air inlet 233, so that the heat energy in the flue gas can be fully utilized and the energy utilization efficiency of the entire system can be improved.

[0037] In this embodiment, the flue gas treatment system 3 includes a cyclone dust collector 31, a spray drying tower 32, a bag filter 33, a semi-dry desulfurization and dust removal system 34, and a centralized emission chimney 35. The flue gas discharged from the hot blast stove 23 passes sequentially through the cyclone dust collector 31, the spray drying tower 32, and the bag filter 33, and finally enters the centralized emission chimney 35 for external discharge. The flue gas discharged from the kiln exhaust system 1 passes sequentially through a primary heat exchanger 21, a secondary heat exchanger 22, and the semi-dry desulfurization and dust removal system 34, and finally enters the centralized emission chimney 35 for external discharge. The flue gas discharged from both the hot blast stove 23 and the kiln exhaust system 1 is treated to meet emission standards.

[0038] In this embodiment, the kiln exhaust system 1 includes a primary exhaust device 11 and a secondary exhaust device 12; both the primary exhaust device 11 and the secondary exhaust device 12 are connected to a primary heat exchanger 21. The primary heat exchanger 21 can effectively recover and utilize the heat energy in the flue gas discharged from the primary exhaust device 11 and the secondary exhaust device 12, avoiding direct emission of flue gas into the atmosphere and reducing energy waste.

[0039] In summary, this ceramic factory flue gas waste heat recovery system can solve the problem in existing technologies where the heat energy of kiln flue gas is directly dissipated after treatment without being recovered and utilized.

[0040] Where there is no conflict, the above embodiments and features can be combined with each other.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit the scope of protection of this utility model. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the essence and scope of the technical solutions of this utility model.

Claims

1. A waste heat recovery system for flue gas from a ceramics factory, characterized in that: It includes a kiln exhaust system (1), a flue gas waste heat recovery system (2), and a flue gas treatment system (3); the flue gas waste heat recovery system (2) is connected to the kiln exhaust system (1) and the flue gas treatment system (3); the flue gas waste heat recovery system (2) is used to recover and utilize the heat energy in the flue gas discharged from the kiln exhaust system (1), and the flue gas treatment system (3) is used to treat the flue gas discharged from the kiln exhaust system (1) and the flue gas waste heat recovery system (2) before discharging it; The flue gas waste heat recovery system (2) includes a primary heat exchanger (21), a secondary heat exchanger (22), a hot blast stove (23), a drying kiln (24), and a heating fan (25); the two ends of the hotter medium channel of the primary heat exchanger (21) are connected to the secondary heat exchanger (22) and the kiln exhaust system (1), respectively, and the two ends of the colder medium channel of the primary heat exchanger (21) are connected to the heating fan (25) and the drying kiln (24), respectively; the two ends of the hotter medium channel of the secondary heat exchanger (22) are connected to the primary heat exchanger (21) and the flue gas treatment system (3), respectively, and the two ends of the colder medium channel of the secondary heat exchanger (22) are connected to the hot blast stove (23) and the drying kiln (24), respectively; the hot blast stove (23) is connected to the flue gas treatment system (3).

2. The ceramic factory flue gas waste heat recovery and treatment system according to claim 1, characterized in that: A first valve (271) is provided between the primary heat exchanger (21) and the secondary heat exchanger (22), and a second valve (272) is provided between the secondary heat exchanger (22) and the flue gas treatment system (3). A pipe is connected between the primary heat exchanger (21) and the first valve (271), and the pipe connects to the second valve (272) and the flue gas treatment system (3). A third valve (273) is provided on the pipe.

3. The waste heat recovery system for ceramic factory flue gas according to claim 1, characterized in that: A dehumidifying fan (26) is installed between the secondary heat exchanger (22) and the drying kiln (24).

4. The waste heat recovery system for ceramic factory flue gas according to claim 1, characterized in that: The hot air furnace (23) is equipped with a burner (231); a combustion fan (232) is provided between the burner (231) and the secondary heat exchanger (22), the combustion fan (232) is connected to the secondary heat exchanger (22) through the fourth valve (274), and the burner (231) is connected to a natural gas pipeline.

5. The ceramic factory flue gas waste heat recovery system according to claim 4, characterized in that: The combustion fan (232) is also connected to a natural air duct via a fifth valve (275).

6. The ceramic factory flue gas waste heat recovery system according to claim 5, characterized in that: The hot air furnace (23) is also equipped with a cold air outlet (233), which is connected to the secondary heat exchanger (22) through the sixth valve (276).

7. The waste heat recovery system for ceramic factory flue gas according to claim 6, characterized in that: The air vent (233) is also connected to a natural air duct via a seventh valve (277).

8. The ceramic factory flue gas waste heat recovery system according to claim 1, characterized in that: The flue gas treatment system (3) includes a cyclone dust collector (31), a spray drying tower (32), a bag filter (33), a semi-dry desulfurization and dust removal system (34), and a centralized emission chimney (35). The flue gas discharged from the hot blast stove (23) passes through the cyclone dust collector (31), the spray drying tower (32), and the bag filter (33) in sequence, and finally enters the centralized emission chimney (35) for external discharge. The flue gas discharged from the kiln exhaust system (1) passes through the primary heat exchanger (21), the secondary heat exchanger (22), and the semi-dry desulfurization and dust removal system (34) in sequence, and finally enters the centralized emission chimney (35) for external discharge.

9. The waste heat recovery system for ceramic factory flue gas according to claim 1, characterized in that: The kiln exhaust system (1) includes a primary exhaust device (11) and a secondary exhaust device (12); both the primary exhaust device (11) and the secondary exhaust device (12) are connected to the primary heat exchanger (21).

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