Coke oven heating system adopting oxygen-enriched combustion
By employing oxygen-enriched combustion and waste gas preheating technologies in the coke oven heating system, the problems of low radiative heat transfer efficiency and high-temperature zone concentration caused by air-assisted combustion have been solved, achieving coke oven heating effects with high-efficiency heat transfer and low nitrogen oxide generation.
Patent Information
- Application Number
- CN202520390248.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2035-03-07
AI Technical Summary
In existing coke oven heating systems, air is used as the combustion-supporting gas, resulting in a high nitrogen content in the exhaust gas after combustion. This reduces the efficiency of radiative heat transfer and generates a large amount of nitrogen oxides. Furthermore, the concentrated combustion temperature leads to problems in the high-temperature zone.
An oxygen-enriched combustion system is adopted, which divides the combustion chamber into two vertical combustion channels by setting up a partition wall. The exhaust gas is used to preheat the oxygen-enriched gas, and the gas and oxygen-enriched gas are mixed for combustion. The radiation intensity in the combustion chamber is increased by utilizing the radiation capacity of polar triatomic molecules carbon dioxide and water vapor. At the same time, the combustion temperature is controlled by exhaust gas recirculation and local high-temperature points to reduce the generation of nitrogen oxides.
It improves heat transfer efficiency, achieves uniform temperature distribution, reduces nitrogen oxide generation, improves the high-temperature heating effect of the coke oven, and shortens the coking time.
Smart Images
Figure CN223620337U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of coke oven heating technology, specifically to a coke oven heating system that uses oxygen-enriched combustion. Background Technology
[0002] A coke oven consists of a regenerator, inclined flue, combustion chamber, carbonization chamber, and oven roof. In existing coke oven heating systems, the fuel gas is coal gas, mostly coke oven gas or blast furnace gas, while the combustion-supporting gas is air. The coal gas and air are mixed and burned in the vertical flue of the combustion chamber. The hot exhaust gas flows up and down in the vertical flue, and the heat is transferred through the furnace wall of the combustion chamber to the coal in the carbonization chamber through heat conduction and heat radiation, so that the coal is converted into coke.
[0003] The following problems exist in the heating process of coke ovens: First, to ensure complete combustion, the excess air coefficient is usually above 1.2 during operation. However, since about 78% of air is non-combustible nitrogen, the nitrogen content in the exhaust gas after combustion is above 75% or even higher. Because nitrogen is a non-polar diatomic molecule and has no radiative capacity, it undoubtedly reduces the radiation intensity in the combustion chamber, thereby reducing the heat transfer efficiency of the furnace. Second, the high-temperature zone after the mixture of air and coal gas is relatively concentrated. The high combustion temperature in this zone leads to the generation of a large amount of nitrogen oxides. Therefore, it is objectively necessary to develop a coke oven heating system with high heat transfer efficiency, uniform temperature distribution, and low nitrogen oxide generation using oxygen-enriched combustion. Utility Model Content
[0004] The purpose of this invention is to provide a coke oven heating system with high heat transfer efficiency, uniform temperature distribution, and low nitrogen oxide generation that uses oxygen-enriched combustion.
[0005] The purpose of this utility model is achieved as follows: It includes a combustion chamber and a regenerator. The combustion chamber is divided into several double-unit vertical flues by a partition wall. An oxygen-enriching pipe is installed on the regenerator, and a gas mixer is installed on the oxygen-enriching pipe. The exhaust pipe of the regenerator is connected to the gas mixer via a branch pipe. A vertical wall is installed in the middle of the double-unit vertical flues, dividing the double-unit vertical flues into an upper gas flue and a lower gas flue. A crossing hole is provided between the upper end of the vertical wall and the furnace top of the regenerator. An exhaust gas recirculation hole is provided at the bottom of the vertical wall. The bottom of the upper gas flue... The combustion chamber is connected to the regenerator via an oxygen-enriched inclined channel. The bottom of the lower gas flue is connected to the regenerator via an exhaust gas inclined channel. A gas chamber and an oxygen-enriched chamber are installed inside the vertical wall. The bottom of the oxygen-enriched chamber is connected to the oxygen-enriched inclined channel via a branch inclined channel. The oxygen-enriched chamber has multiple oxygen-enriched holes connected to the upper and lower gas flues respectively from bottom to top. Each oxygen-enriched hole is connected to a gas chamber above the gas chamber. The top of the combustion chamber is a hollow structure. The top of the gas chamber is connected to the hollow structure of the top of the furnace via a connecting pipe. A gas inlet pipe is installed on the top of the furnace.
[0006] Furthermore, a wet coal drying box is connected to the exhaust pipe.
[0007] Furthermore, an oxygen concentration analyzer is installed inside the gas mixer.
[0008] Furthermore, several air-blocking protrusions are installed on the partition wall between the combustion chamber and the coke oven carbonization chamber.
[0009] Furthermore, several grooves are provided on the inner walls of the gas chamber and the oxygen-enriched chamber.
[0010] Furthermore, the vertical wall is provided with several exhaust gas passages that connect the upper and lower gas channels at intervals.
[0011] In operation, this invention uses oxygen-enriched gas instead of air. A portion of the exhaust gas from the regenerator, along with the oxygen-enriched gas, is introduced into a gas mixer. This process utilizes the heat from the exhaust gas to preheat the oxygen-enriched gas and adjusts its oxygen content through mixing. The oxygen-enriched gas, containing a certain amount of exhaust gas, is then introduced into the regenerator for preheating, raising its temperature. Once the temperature rises, the oxygen-enriched gas is introduced into the upper gas flue, drawing the exhaust gas flowing from the exhaust gas circulation hole upwards. This flow then draws the coal gas and oxygen-enriched gas flowing from the gas hole and oxygen-enriched gas upwards, continuously burning and generating high-temperature exhaust gas to dry-distill and coke the coal in the coke oven's carbonization chamber. This process is repeated, with the airflow flowing in the upper and lower gas flues, continuously introducing new coal gas and oxygen-enriched gas, and continuously burning to generate high-temperature exhaust gas, thus achieving the coking of the coal. In this invention, a gas chamber and an oxygen-enriched chamber are installed within the vertical wall. During operation, coal gas is introduced into the gas chamber, then into the upper and lower gas flues, while oxygen-enriched gas is introduced into the oxygen-enriched chamber, then into the upper and lower gas flues. This allows the coal gas and oxygen-enriched gas to absorb heat from the flues before entering them, preheating the combustion chambers and reducing their temperature to some extent, thus decreasing the amount of nitrogen oxides produced in the exhaust gas. Secondly, this invention uses oxygen-enriched gas instead of air as the combustion-supporting gas in the coke oven heating system. The main components of the exhaust gas after combustion are carbon dioxide and water vapor, both polar triatomic molecules. Compared to nitrogen, these have a stronger radiative capacity, improving the combustion chamber's efficiency. The increased radiation intensity improves the radiative heat transfer efficiency within the combustion chamber, shortening the coking time. Furthermore, in this invention, the main combustion area is concentrated at the gas and air ejection points, with these points spaced apart within the upper and lower gas flues. This increases the number of localized high-temperature points in the vertical flues, allowing for better control of the combustion state and temperature, averaging the exhaust gas temperature within the flues, and preventing the concentration of combustion and high-temperature zones. Simultaneously, the ability of the exhaust gas to circulate through the exhaust gas circulation holes increases the flame length, improves the upward heating of the coke oven, mitigates the concentration of high-temperature zones, and to some extent reduces the exhaust gas temperature, decreasing nitrogen oxide production and thus lowering the nitrogen oxide content in the exhaust gas. In summary, this invention offers advantages such as high heat transfer efficiency, uniform temperature distribution, and low nitrogen oxide generation. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0013] Figure 2 This is a schematic diagram of the combustion chamber 1 in this utility model;
[0014] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of AA;
[0015] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure of BB;
[0016] Figure 5 This is a schematic diagram of the structure of the air-blocking protrusion 21 in this utility model;
[0017] In the diagram: 1-combustion chamber, 2-regenerator chamber, 3-partition wall, 4-oxygen enrichment pipe, 5-gas mixer, 6-vertical wall, 7-upper gas flue, 8-lower gas flue, 9-exhaust gas circulation hole, 10-oxygen enrichment inclined duct, 11-exhaust gas inclined duct, 12-gas chamber, 13-oxygen enrichment chamber, 14-branch inclined duct, 15-oxygen enrichment hole, 16-gas hole, 17-gas inlet pipe, 18-wet coal drying box, 19-oxygen concentration analyzer, 20-carbonization chamber, 21-gas baffle protrusion, 22-groove, 23-exhaust gas passage. Detailed Implementation
[0018] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.
[0019] like Figures 1-5 As shown, this utility model includes a combustion chamber 1 and a regenerator 2. The combustion chamber 1 is divided into several double-unit vertical flues by a partition wall 3. An oxygen-enriching pipe 4 is installed on the regenerator 2, and a gas mixer 5 is installed on the oxygen-enriching pipe 4. The exhaust pipe of the regenerator 2 is connected to the gas mixer 5 through a branch pipe. A vertical wall 6 is installed in the middle of the double-unit vertical flues, dividing the double-unit vertical flues into an upper gas flue 7 and a lower gas flue 8. A crossing hole is provided between the upper end of the vertical wall 6 and the furnace top of the regenerator 2. An exhaust gas circulation hole 9 is provided at the bottom of the vertical wall 6. The bottom of the upper gas flue 7 is connected to the regenerator 2 through an oxygen-enriching inclined channel 10, and the bottom of the lower gas flue 8 is connected to the regenerator 2 through an exhaust gas inclined channel 11. The wall 6 contains a gas chamber 12 and an oxygen-enriched chamber 13. The bottom of the oxygen-enriched chamber 13 is connected to the oxygen-enriched inclined channel 10 via a branch inclined channel 14. The oxygen-enriched chamber 13 has multiple oxygen-enriched holes 15 connected to the upper gas channel 7 and the lower gas channel 8 respectively from bottom to top. Each oxygen-enriched hole 15 is connected to the gas chamber 12 above it. The top of the combustion chamber 1 is a cavity structure. The top of the gas chamber 12 is connected to the cavity of the top of the furnace via a connecting pipe. A gas inlet pipe 17 is installed on the top of the furnace. Before entering the gas chamber 12, the gas will first enter the cavity of the top of the furnace. In the cavity of the top of the furnace, the gas can absorb the heat in the combustion chamber 1, increase the gas temperature, and achieve the purpose of gas preheating.
[0020] In operation, this invention uses oxygen-enriched gas instead of air. A portion of the exhaust gas from the regenerator 2, along with the oxygen-enriched gas, is introduced into the gas mixer 5. On one hand, the heat in the exhaust gas is used to preheat the oxygen-enriched gas; on the other hand, the oxygen content in the oxygen-enriched gas is adjusted by mixing the exhaust gas. Subsequently, the oxygen-enriched gas containing a certain amount of exhaust gas is introduced into the regenerator 2 for preheating, raising the temperature of the oxygen-enriched gas. After the temperature of the oxygen-enriched gas rises, it is introduced into the upper gas flue 7, which swirls the exhaust gas flowing from the exhaust gas circulation hole 9 upwards. Then, it swirls the coal gas and oxygen-enriched gas flowing from the coal gas hole 16 and the oxygen-enriched gas hole 15 upwards, continuously burning and generating high-temperature exhaust gas to dry-distill and coke the coal in the coke oven carbonization chamber 20. This process is repeated, with the airflow flowing in the upper gas flue 7 and the lower gas flue 8, continuously introducing new coal gas and oxygen-enriched gas, continuously burning and generating high-temperature exhaust gas to achieve the coking treatment of the coal.
[0021] In this invention, a gas chamber 12 and an oxygen-enriched chamber 13 are provided within the vertical wall 6. During operation, coal gas is introduced into the gas chamber 12, and then into the upper gas flue 7 and the lower gas flue 8. Oxygen-enriched gas is introduced into the oxygen-enriched chamber 13, and then into the upper gas flue 7 and the lower gas flue 8. In this way, before entering the upper and lower gas flues 7 and 8, the coal gas and oxygen-enriched gas can absorb heat from each flue, thus preheating and reducing the temperature within the flues to a certain extent, thereby reducing the amount of nitrogen oxides produced in the exhaust gas. Secondly, this invention uses oxygen-enriched gas instead of air as the combustion-supporting gas in the coke oven heating system. The main components of the exhaust gas after combustion are carbon dioxide and water vapor, both of which are polar triatomic molecules. Compared to nitrogen, these have a stronger radiative capacity, improving… The radiation intensity in combustion chamber 1 is increased, thereby improving the radiative heat transfer efficiency in combustion chamber 1 and shortening the coking time. In addition, in this invention, the main combustion area is concentrated at the location where the gas and air are ejected, and these locations are distributed at intervals in the upper gas flue 7 and lower gas flue 8. This increases the number of local high-temperature points in the vertical flue, which can better control the combustion state and combustion temperature, average the exhaust gas temperature in the flue, and prevent the problem of concentrated combustion area and high-temperature area. At the same time, since the exhaust gas can circulate through the exhaust gas circulation hole 9, it is beneficial to increase the flame length, improve the high-temperature heating of the coke oven, improve the problem of high-temperature area concentration, reduce the temperature of the exhaust gas to a certain extent, reduce the production of nitrogen oxides, and thus reduce the content of nitrogen oxides in the exhaust gas.
[0022] The exhaust pipe is connected to a wet coal drying box 18. The exhaust gas still contains a certain amount of heat. It is passed into the wet coal drying box 18 to dry the wet coal and reduce the moisture content of the wet coal. This method is used to recover and utilize the heat in the exhaust gas and reduce heat loss.
[0023] An oxygen concentration analyzer 19 is installed inside the gas mixer 5. This analyzer, a readily available instrument, is used to detect the oxygen concentration in the gas mixer 5, facilitating the adjustment of the oxygen content in the oxygen-enriched gas. Specifically, the flow rates of the oxygen-enriched gas and the exhaust gas can be adjusted as required, thereby regulating their ratio within the gas mixer 5 and ultimately controlling the oxygen content in the mixed gas. In this invention, the oxygen content of the oxygen-enriched gas can be 30%–80%, and the oxygen content of the mixed gas after mixing with the exhaust gas is controlled at approximately 50%.
[0024] Several gas-blocking protrusions 21 are provided on the partition wall between the combustion chamber 1 and the coke oven carbonization chamber 20. After the gas-blocking protrusions 21 are installed, compared with the existing vertical unobstructed combustion chamber 1, the gas-blocking protrusions 21 can change the flow state of the combustion gas in the vertical flue, increase the turbulence ratio of the flowing gas, thereby improving the heat transfer efficiency of the high-temperature gas, and at the same time increase the local high-temperature points in the vertical flue, thereby improving the uniformity of the vertical flue heating, which is more conducive to the uniform maturation of coke.
[0025] Several grooves 22 are provided on the inner walls of the gas chamber 12 and the oxygen-enriched chamber 13. The grooves 22 can increase the surface area of the inner walls of the gas chamber 12 and the oxygen-enriched chamber 13, thereby increasing the heat exchange area of the gas, the oxygen-enriched gas and the waste gas, improving the preheating effect of the gas and the oxygen-enriched gas, reducing the temperature of the waste gas in the upper gas flue 7 and the lower gas flue 8, further reducing the production of nitrogen oxides and reducing the content of nitrogen oxides in the waste gas.
[0026] The vertical wall 6 is provided with several exhaust gas passages 23 at intervals, connecting the upper gas passage 7 and the lower gas passage 8. The exhaust gas passages 23 allow more exhaust gas to enter the upper gas passage 7 from the lower gas passage 8, increasing the amount of exhaust gas circulating. On the one hand, the increased amount of exhaust gas circulating can effectively reduce the content of pollutants such as nitrogen oxides in the exhaust gas. On the other hand, the increased amount of exhaust gas circulating is conducive to extending the flame length and improving the high-altitude heating of the coke oven. Uniform high-altitude heating of the coke oven is conducive to improving coke quality and shortening coking time.
Claims
1. A coke oven heating system employing oxygen-enriched combustion, comprising a combustion chamber (1) and a regenerator (2), wherein the combustion chamber (1) is divided into several double-connected vertical flues by partition walls (3), characterized in that... The regenerator (2) is equipped with an oxygen-enriched pipe (4) and a gas mixer (5). The exhaust pipe of the regenerator (2) is connected to the gas mixer (5) via a branch pipe. A vertical wall (6) is provided in the middle of the double vertical flue. The vertical wall (6) divides the double vertical flue into an upper gas flue (7) and a lower gas flue (8). A cross-pass hole is provided between the upper end of the vertical wall (6) and the top of the regenerator (2). An exhaust gas circulation hole (9) is provided at the bottom of the vertical wall (6). The bottom of the upper gas flue (7) is connected to the regenerator (2) via an oxygen-enriched inclined channel (10). The bottom of the lower gas flue (8) is connected to the regenerator (2) via an exhaust gas inclined channel (11). The gas chamber (1) is connected to the heat storage chamber (2). The vertical wall (6) is provided with a gas chamber (12) and an oxygen-enriched chamber (13). The bottom of the oxygen-enriched chamber (13) is connected to the oxygen-enriched inclined channel (10) through the branch inclined channel (14). The oxygen-enriched chamber (13) is provided with multiple oxygen-enriched holes (15) connected to the upper gas channel (7) and the lower gas channel (8) respectively from bottom to top. Each oxygen-enriched hole (15) is provided with a gas hole (16) on the gas chamber (12) above it. The top of the combustion chamber (1) is a cavity structure. The top of the gas chamber (12) is connected to the cavity of the top of the furnace through a connecting pipe. A gas inlet pipe (17) is provided on the top of the furnace.
2. The coke oven heating system employing oxygen-enriched combustion according to claim 1, characterized in that: The exhaust pipe is connected to a wet coal drying box (18).
3. A coke oven heating system employing oxygen-enriched combustion according to claim 1, characterized in that: An oxygen concentration analyzer (19) is installed inside the gas mixer (5).
4. A coke oven heating system employing oxygen-enriched combustion according to claim 1, characterized in that: Several air-blocking protrusions (21) are provided on the partition wall between the combustion chamber (1) and the coke oven carbonization chamber (20).
5. A coke oven heating system employing oxygen-enriched combustion according to claim 1, characterized in that: The inner walls of the gas chamber (12) and the oxygen-enriched chamber (13) are provided with several grooves (22).
6. A coke oven heating system employing oxygen-enriched combustion according to claim 1, characterized in that: The vertical wall (6) is provided with several exhaust gas passages (23) that connect the upper gas passage (7) and the lower gas passage (8) at intervals.