Lime kiln flue gas denitration device
By using flue gas heat exchanger, burner, SCR denitrifier and waste heat recovery device in lime kiln flue gas denutrition device, the problems of high energy consumption and high temperature flue gas emissions in traditional methods are solved, and efficient nitrogen oxide removal is achieved and waste heat recovery reduces operating costs and atmospheric temperature.
Patent Information
- Application Number
- CN202420774651.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-15
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-04-15
AI Technical Summary
Traditional lime kiln flue gas treatment methods have problems such as high energy consumption, high operating costs, and high flue gas temperature of lime kiln after denitrification, resulting in increased atmospheric temperature and waste of resources.
A lime kiln flue gas denitrition device is designed, including flue gas heat exchanger, burner, SCR denitrifier, waste heat recovery and induced fan. The heat before and after denitrification is recovered through the flue gas heat exchanger, and the burner provides a heat source. SCR The denitrifier uses low-temperature catalysts, precise ammonia spray control system and forced circulation waste heat recovery device to reduce energy consumption and improve hot water utilization.
It reduces the energy consumption of denitrification of lime kiln flue gas, reduces heat dissipation losses during high-temperature flue gas transmission, achieves efficient nitrogen oxide removal, reduces ammonia consumption, and provides in-plant heating through waste heat recovery.
Smart Images
Figure CN222239634U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lime kiln flue gas denitration, in particular to a lime kiln flue gas denitration device. Background Art
[0002] In current industrial production, lime kilns, as important basic raw material production equipment, inevitably produce a large amount of flue gas containing nitrogen oxides when calcining limestone under high temperature conditions. These nitrogen oxides not only cause serious damage to the quality of the atmospheric environment and affect climate change, but also fail to meet the requirements of increasingly stringent environmental protection regulations and relevant national emission standards.
[0003] Traditional lime kiln flue gas treatment methods have problems such as high energy consumption and high operating costs. The flue gas temperature required for denitrification is high, so the lime kiln flue gas needs to be heated. A hot blast furnace is often set up separately for heating. The investment in the hot blast furnace is large, and the lime kiln flue gas after denitrification is still at a relatively high temperature. Directly discharging it will cause the atmospheric temperature to rise and waste resources. Utility Model Content
[0004] The purpose of the utility model is to solve the problems raised in the above background technology, and then propose a lime kiln flue gas denitrification device.
[0005] The technical solution adopted by the utility model to solve its technical problems is:
[0006] A lime kiln flue gas denitrification device comprises a flue gas heat exchanger, a burner, an SCR denitrifier, a waste heat recovery device, an induced draft fan and a lime kiln chimney; the flue gas heat exchanger comprises a low temperature side and a high temperature side, the low temperature side inlet is used to be connected to the lime kiln air intake port, the low temperature side outlet is connected to the SCR denitrifier inlet, the SCR denitrifier inlet is also connected to the burner so that the lime kiln flue gas enters the SCR denitrifier for denitrification after being burned and heated by the burner, the high temperature side inlet is connected to the SCR denitrifier outlet, the high temperature side outlet is connected to the waste heat recovery device inlet, and the waste heat recovery device outlet is connected to the lime kiln chimney through the induced draft fan so that the purified lime kiln flue gas is discharged into the air at high altitude.
[0007] Furthermore, the burner is installed on the vertical flue at the inlet of the SCR denitrifier to improve the temperature raising effect of the burner on the lime kiln flue gas entering the SCR denitrifier.
[0008] Furthermore, the burner uses coke oven gas as fuel to provide a heat source for heating the lime kiln flue gas.
[0009] Furthermore, the flue gas heat exchanger adopts a rotary gas-to-gas heat exchanger to recover the waste heat of the high-temperature lime kiln flue gas after denitrification.
[0010] Furthermore, it also includes a combustion-supporting fan, which is connected to the burner to increase the combustion intensity of the burner.
[0011] Furthermore, the catalyst in the SCR denitrifier is a low-temperature SCR catalyst to reduce the energy consumption required for heating the lime kiln flue gas.
[0012] Furthermore, a precise ammonia injection control system is provided in the SCR denitrifier to ensure that the reducing agent is fully contacted and effectively reacts within the optimal temperature window.
[0013] Furthermore, the waste heat recovery device is provided with forced circulation to produce hot water for heating in the factory.
[0014] Furthermore, the booster pump in the forced circulation adopts frequency conversion control to adjust the outlet temperature of the heating water and recover the waste heat of the high-temperature lime kiln flue gas after denitrification.
[0015] Compared with the prior art, the beneficial effects of the utility model are:
[0016] The beneficial effects of the utility model are:
[0017] 1. The utility model adopts a flue gas heat exchanger to exchange heat between the lime kiln flue gas before and after denitrification, which not only meets the requirements of the SCR denitrifier on the denitrification temperature of the lime kiln flue gas, but also reduces the temperature of the lime kiln flue gas after denitrification, and reduces the energy consumption of heating the lime kiln flue gas before denitrification; by arranging a flue burner at the entrance of the SCR denitrifier, the investment in setting up a separate hot air furnace is saved, and the heat dissipation loss during the transportation of the high-temperature lime kiln flue gas is reduced; and the waste heat of the high-temperature lime kiln flue gas after denitrification can be recovered through the waste heat recovery device, saving energy.
[0018] 2. The utility model sets a precise ammonia injection control system in the SCR denitrifier to ensure that the reducing agent is fully contacted and effectively reacts within the optimal temperature window, thereby reducing ammonia water consumption and ammonia escape, and reducing ammonia evaporation energy consumption.
[0019] 3. The utility model can effectively produce hot water for heating in the factory by setting forced circulation at the waste heat recovery device, thereby improving the use value. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a schematic diagram of the structure of the utility model;
[0021] Figure 2 This is a schematic diagram of the installation location of the precision ammonia injection system;
[0022] Among them: 1. Flue gas heat exchanger; 11. Low temperature side; 12. High temperature side; 2. Burner; 3. SCR denitrifier; 4. Waste heat recovery device; 5. Induced draft fan; 6. Lime kiln chimney; 7. Combustion-supporting fan; 8. Precision ammonia injection system; 9. Forced circulation. DETAILED DESCRIPTION
[0023] 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 in 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. The utility model is further described in combination with the drawings and embodiments:
[0024] See attached Figure 1 As shown, a lime kiln flue gas denitrification device comprises a flue gas heat exchanger 1, a burner 2, an SCR denitrifier 3, a waste heat recovery device 4, an induced draft fan 5 and a lime kiln chimney 6; wherein, the flue gas heat exchanger 1 comprises a low temperature side 11 and a high temperature side 12, the inlet of the low temperature side 11 is used to be connected to the lime kiln air intake port, the outlet of the low temperature side 11 is connected to the inlet of the SCR denitrifier 3, the inlet of the SCR denitrifier 3 is also connected to the burner 2 so that the lime kiln flue gas enters the SCR denitrifier 3 for denitrification after being burned and heated by the burner 2, wherein the burner 2 uses coke oven gas as fuel to provide a heat source for heating the lime kiln flue gas, the inlet of the high temperature side 12 is connected to the outlet of the SCR denitrifier 3, the outlet of the high temperature side 12 is connected to the inlet of the waste heat recovery device 4, and the outlet of the waste heat recovery device 4 is connected to the lime kiln chimney 6 through the induced draft fan so that the purified lime kiln flue gas is discharged into the air.
[0025] In the above scheme, considering the temperature raising effect of the burner 2 on the lime kiln flue gas entering the SCR denitrifier 3 , the burner 2 is installed on the vertical flue at the entrance of the SCR denitrifier 3 .
[0026] In addition, the flue gas heat exchanger 1 adopts the rotary gas-to-gas heat exchanger in the prior art to recover the waste heat of the high-temperature lime kiln flue gas after denitrification. The flue gas heat exchanger 1 is used in conjunction with the SCR denitrifier 3 to recover the waste heat of the high-temperature lime kiln flue gas after denitrification. Through the heat exchange between the low-temperature original lime kiln flue gas before denitrification and the high-temperature clean lime kiln flue gas after denitrification, the heating temperature difference of the original lime kiln flue gas before denitrification is reduced, and the emission temperature of the clean lime kiln flue gas after denitrification is reduced, thereby realizing heat recovery and improving heat utilization efficiency.
[0027] Next, considering the combustion efficiency of the burner 2, a lime kiln flue gas denitrification device also includes a combustion-supporting fan 7, which is connected to the burner 2 to increase the combustion intensity of the burner 2. During the implementation process, the air blown in by the combustion-supporting fan 7 and the coke oven gas are burned through the flue burner 2 to form hot flue gas. The hot flue gas is mixed with the un-denitrified lime kiln flue gas to increase the flue gas temperature. The lime kiln flue gas temperature is increased to meet the denitrification requirements, and the subsequent SCR denitrifier 3 improves the treatment effect of the lime kiln flue gas. At the same time, the lime kiln flue gas is heated to a higher temperature to regenerate the catalyst in the SCR denitrifier 3; for this reason, the catalyst in the SCR denitrifier 3 is a low-temperature SCR catalyst to reduce the energy consumption required for heating the lime kiln flue gas.
[0028] During the specific implementation of the device, the lime kiln flue gas is first heated by the low temperature side 11 of the flue gas heat exchanger 1, and the temperature of the lime kiln flue gas is increased to about 150°C. The heated lime kiln flue gas passes through the burner 2 to increase the temperature of the lime kiln flue gas to not less than 180°C and then enters the SCR denitrifier 3. The lime kiln flue gas at the outlet of the SCR denitrifier 3 enters the high temperature side 12 of the flue gas heat exchanger 1 for cooling, and the temperature is reduced to about 110°C. The cooled lime kiln flue gas is sent to the lime kiln chimney 6 through the induced draft fan 5. After the lime kiln flue gas is treated, NOx is less than 100mg / Nm3, reaching the ultra-low emission standard.
[0029] In addition, refer to the attached Figure 2 As shown, the SCR denitrifier 3 is provided with a precise ammonia injection control system, which is a prior art and will not be elaborated in this application. The precise ammonia injection control system is used to ensure that the reducing agent is fully contacted and effectively reacts within the optimal temperature window.
[0030] In addition, refer to the attached Figure 2 As shown, the waste heat recovery device 4 is provided with a forced circulation 9 to produce hot water for heating in the factory. The forced circulation 9 forces the water to circulate through a pump, thereby achieving the purpose of accelerating the heat exchange speed and improving the heat exchange effect. The forced circulation 9 can better control factors such as temperature, flow rate and water replacement cycle, so as to make the waste heat recovery more efficient. The forced circulation 9 is an existing common technology and this application will not elaborate on it in detail. In addition, the booster pump in the forced circulation 9 adopts frequency conversion control to adjust the outlet water temperature of the heating water and recover the waste heat of the high-temperature smoky lime kiln gas after denitrification.
[0031] The above shows and describes the basic principles, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions in the specification are only to illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the protection required by the utility model. The scope of protection required by the utility model is defined by the attached claims and their equivalents.
Claims
1. A lime kiln flue gas denitrification device, characterized in that: It includes a flue gas heat exchanger (1), a burner (2), an SCR denitrifier (3), a waste heat recovery device (4), an induced draft fan (5) and a lime kiln chimney (6); The flue gas heat exchanger (1) comprises a low temperature side (11) and a high temperature side (12), wherein the inlet of the low temperature side (11) is connected to the air intake port of the lime kiln, the outlet of the low temperature side (11) is connected to the inlet of the SCR denitrifier (3), the inlet of the SCR denitrifier (3) is also connected to the burner (2), the inlet of the high temperature side (12) is connected to the outlet of the SCR denitrifier (3), the outlet of the high temperature side (12) is connected to the inlet of the waste heat recovery device (4), and the outlet of the waste heat recovery device (4) is connected to the lime kiln chimney (6) through an induced draft fan.
2. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The burner (2) is installed on the vertical flue at the inlet of the SCR denitrifier (3).
3. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The burner (2) uses coke oven gas as fuel.
4. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The flue gas heat exchanger (1) is a rotary gas-to-gas heat exchanger.
5. A lime kiln flue gas denitrification device according to claim 1, characterized in that: It also includes a combustion-supporting fan (7), which is connected to the burner (2).
6. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The catalyst in the SCR denitrifier (3) is a low-temperature SCR catalyst.
7. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The SCR denitrifier (3) is provided with a precise ammonia injection control system.
8. A lime kiln flue gas denitrification device according to claim 1, characterized in that: The waste heat recovery device (4) is provided with a forced circulation (9).
9. A lime kiln flue gas denitrification device according to claim 8, characterized in that: The booster pump in the forced circulation (9) is controlled by variable frequency.