Single-heat coke oven low-nitrogen combustion structure

Abstract

The present application relates to single hot coke oven, especially to a low nitrogen combustion structure of single hot coke oven. It comprises a small flue, a regenerator, an inclined path and a combustion chamber. The combustion chamber is composed of double fireways. Each two vertical fireways form a pair of double fireways. The upper parts of the ascending vertical fireway and the descending vertical fireway of the double fireway are connected through a span hole. Each vertical fireway is composed of a coke oven gas inlet, an ascending air multi-stage outlet, an ascending return gas multi-stage outlet and a descending waste gas multi-stage outlet. The return gas passage and the coke oven gas passage are arranged in the main wall of the regenerator. They are directly connected to the lower part of the vertical fireway from the underground room of the coke oven. When ascending, the coke oven gas passage and the return gas passage are opened. When descending, the coke oven gas passage and the return gas passage are closed. The present application effectively reduces the intensity of combustion in the vertical fireway, improves the vertical heating uniformity of the vertical fireway during operation, reduces the generation of nitrogen oxides, reduces the emission of atmospheric pollutants, saves the cost of tail gas treatment.

Description

Technical Field

[0001] This invention relates to a single-heat coke oven, and more particularly to a low-NOx combustion structure for a single-heat coke oven. Background Technology

[0002] With rapid industrial development, coordinating the relationship between humanity and nature and ensuring the sustainable development of the economy and society have become increasingly important. In the coking industry, independent coking enterprises using coke oven gas as their gas source account for a significant proportion, and controlling low-NOx emissions from coke ovens has always been a key development direction for coking environmental protection technologies. The standard flue temperature of coke ovens during production exceeds 1300℃, and this ultra-high combustion temperature promotes the rapid and large-scale generation of nitrogen oxides, placing enormous pressure on environmental inspections of exhaust emissions. Nitrogen oxide production mainly occurs through thermal, fuel, and rapid processes; controlling thermal nitrogen oxide generation primarily involves ensuring that the standard flue temperature of the coke oven does not exceed 1300℃.

[0003] Modern large-scale single-heat coke ovens have relatively high vertical flue dimensions. When air and coke oven gas are supplied from the bottom of the vertical flue, the fuel will burn rapidly in the middle of the flue, resulting in excessively high local temperatures, which is not conducive to the control of thermal nitrogen oxides. Therefore, supplying combustion air in multiple stages can reduce the intensity of combustion and improve the uniformity of high-altitude heating in the vertical flue, thereby reducing the nitrogen oxide content in the exhaust gas. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a low-NOx combustion structure for a single-heat coke oven; it effectively reduces the intensity of combustion in the vertical flue of the single-heat coke oven, improves the uniformity of high-altitude heating in the vertical flue during operation, reduces the generation of nitrogen oxides, and lowers atmospheric pollutant emissions.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A low-NOx combustion structure for a single-heat coke oven includes a small flue, a regenerator, an inclined flue, and a combustion chamber. The combustion chamber consists of a double-flue system, with each pair of two vertical flues forming a double-flue system. The upper parts of the rising and falling vertical flues of the double-flue system are connected by a cross-passage. Each vertical flue consists of a coke oven gas inlet, a multi-stage rising air outlet, a multi-stage rising return gas outlet, and a multi-stage falling waste gas outlet. The return gas channel and the coke oven gas channel are both located in the main wall of the regenerator, extending directly from the coke oven basement into the lower part of the vertical flue. When rising, both the coke oven gas channel and the return gas channel are open; when falling, both the coke oven gas channel and the return gas channel are closed.

[0007] The same section of the rising air multi-stage outlet and the descending exhaust gas multi-stage outlet has a height difference.

[0008] The rising air multi-stage outlet includes rising air stage 1 outlet, rising air stage 2 outlet, and rising air stage 3 outlet; the rising return gas multi-stage outlet includes rising return gas stage 1 outlet, rising return gas stage 2 outlet, and rising return gas stage 3 outlet; the descending exhaust gas multi-stage outlet includes descending exhaust gas stage 1 outlet, descending exhaust gas stage 2 outlet, and descending exhaust gas stage 3 outlet.

[0009] The multi-stage outlet for rising air and the multi-stage outlet for rising return air are located in the combustion chamber partition wall, and the height of the first stage outlet for rising return air is between the first stage outlet for rising air and the second stage outlet for rising air, while the height of the second stage outlet for rising return air is between the second stage outlet for rising air and the third stage outlet for rising air.

[0010] The first outlet of the rising air enters the bottom of the vertical combustion chamber from the heat storage chamber via a long inclined channel. The second and third outlets of the rising air enter the bottom of the vertical combustion chamber from the heat storage chamber via a short inclined channel. The air is burned in the rising vertical combustion chamber and enters the descending vertical combustion chamber through the double-chamber crossover hole. The first outlet of the descending exhaust gas enters the descending airflow heat storage chamber via a short inclined channel. The second and third outlets of the descending exhaust gas enter the descending airflow heat storage chamber via a long inclined channel.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. Each vertical flue of the present invention consists of a coke oven gas inlet, multiple rising air outlets, multiple rising return gas outlets, and multiple descending waste gas outlets; the combustion air is supplied into the vertical flue in multiple stages to participate in the staged combustion of the coke oven gas, effectively improving the uniformity of high-altitude heating in the vertical flue.

[0013] 2. Both the return gas distribution channel and the coke oven gas channel are located in the main wall of the regenerator, and directly enter the lower part of the vertical flue from the coke oven basement. When rising, both the coke oven gas channel and the return gas distribution channel are open, and when descending, both the coke oven gas channel and the return gas distribution channel are closed. This invention introduces the return gas into the combustion chamber partition wall through the regenerator partition wall, and supplies it in sections to reduce the high temperature area in the vertical flue and reduce the peak temperature.

[0014] 3. This invention is applicable to independent coke oven enterprises that use coke oven gas as their gas source. Compared with existing single-heat coke ovens, the combustion air is supplied in stages. Furthermore, recycled waste gas is introduced into the combustion system in multiple stages, with the supply points corresponding to the high-temperature zone of the vertical combustion chamber. This effectively reduces the intensity of combustion within the vertical combustion chamber, improves the uniformity of heating in the vertical combustion chamber during operation, reduces the generation of nitrogen oxides, and lowers atmospheric pollutant emissions. Using coke oven gas for heating achieves low nitrogen oxide emissions and saves on tail gas treatment costs. Attached Figure Description

[0015] Figure 1 This is a schematic top view of the structure of the present invention;

[0016] Figure 2 yes Figure 1 AA section view;

[0017] Figure 3 yes Figure 1 BB cross-sectional view;

[0018] Figure 4 yes Figure 1 CC section view;

[0019] Figure 5 This is a three-dimensional structural schematic diagram of the present invention.

[0020] In the diagram: 1-Rising airflow small flue; 2-First stage air regenerator; 3-Second and third stage air regenerators; 4-Descending airflow small flue; 5-First descending airflow regenerator; 6-Second descending airflow regenerator; 7-Long inclined air duct; 8-Short inclined air duct; 9-First stage rising air outlet; 10-Circulation hole; 11-Second stage rising air outlet; 12-Third stage rising air outlet; 13-Double-connected flue crossing hole; 14-Second stage rising return gas outlet; 15-First stage rising return gas outlet; 16-First stage descending exhaust gas outlet; 17-First stage return gas outlet; 18-Second stage return gas outlet; 19-Third stage descending exhaust gas outlet; 20-Second stage descending exhaust gas outlet; 21-Short exhaust gas duct; 22-Long exhaust gas duct; 23-Rising return gas duct; 24-Rising coke oven gas duct; 25-Descending return gas duct; 26-Rising vertical flue; 27-Descending vertical flue; 28-Descending coke oven gas duct. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0022] Example:

[0023] like Figures 1-5 As shown, a low-NOx combustion structure for a single-heat coke oven includes an upward airflow small flue 1, a downward airflow small flue 4, a first-stage air regenerator 2, a second and third-stage air regenerator 3, a first downward airflow regenerator 5, a second downward airflow regenerator 6, a long inclined air duct 7, a short inclined air duct 8, a combustion chamber, and a furnace top.

[0024] The combustion chamber is composed of a double flue, and the flue is equipped with a circulation hole 10. Every two vertical flues form a pair of double flues. The upper part of the rising vertical flue 26 and the falling vertical flue 27 of the double flue are connected by a crossover hole 13. Each vertical flue consists of a coke oven gas inlet, a rising air multi-stage outlet, a rising return gas distribution multi-stage outlet, and a falling exhaust gas multi-stage outlet.

[0025] The rising air multi-stage outlets include rising air stage 1 outlet 9, rising air stage 2 outlet 11, and rising air stage 3 outlet 12; the rising return gas multi-stage outlets include rising return gas stage 1 outlet 15, rising return gas stage 2 outlet 14; the descending exhaust gas multi-stage outlets include descending exhaust gas stage 1 outlet 16, descending exhaust gas stage 2 outlet 20, and descending exhaust gas stage 3 outlet 19. Additionally, there are descending return gas stage 1 outlet 17 and descending return gas stage 2 outlet 18.

[0026] The rising air multi-stage outlet and the rising return air multi-stage outlet are located in the partition wall between the rising vertical fire channel 26 and the falling vertical fire channel 27. The height of the rising return air first stage outlet 15 is between the rising air first stage outlet 9 and the rising air second stage outlet 11, and the height of the rising return air second stage outlet 14 is between the rising air second stage outlet 11 and the rising air third stage outlet 12.

[0027] The rising air first stage outlet 9 and the descending exhaust gas first stage outlet 16, the rising air second stage outlet 11 and the descending exhaust gas second stage outlet 20, and the rising air third stage outlet 12 and the descending exhaust gas third stage outlet 19 all have a height difference.

[0028] Adjusting bricks are installed at the second stage outlet 11 and the third stage outlet 12 of the rising air, and at the second stage outlet 20 and the third stage outlet 19 of the descending exhaust gas.

[0029] The rising air first outlet 9 enters the bottom of the vertical combustion chamber from the first air regenerator 2 via the long air inclined channel 7. The rising air second outlet 11 and rising air third outlet 12 enter the bottom of the vertical combustion chamber from the second and third air regenerator 3 via the short air inclined channel 8. Combustion occurs in the rising vertical combustion chamber 26, and the gas enters the descending vertical combustion chamber 27 via the double combustion chamber crossing hole 13. The descending exhaust gas first outlet 16 enters the second descending airflow regenerator 6 via the exhaust gas short inclined channel 21. The descending exhaust gas second outlet 20 and descending exhaust gas third outlet 19 enter the first descending airflow regenerator 5 via the exhaust gas long inclined channel 22.

[0030] The gas return rising channel 23, the gas return falling channel 25, the coke oven gas rising channel 24, and the coke oven gas falling channel 28 are all located in the main wall of the regenerator, and are directly connected from the coke oven basement to the lower part of the vertical flue. When rising, the coke oven gas rising channel 24 and the rising gas return second stage outlet 14 and the rising gas return first stage outlet 15 are all open. When falling, the coke oven gas falling channel 28 and the rising gas return first stage falling outlet 17 and the rising gas return second stage falling outlet 18 are all closed.

[0031] This invention is applicable to independent coke oven enterprises that use coke oven gas as their gas source. Compared with existing single-heat coke ovens, the combustion air is supplied in stages. Furthermore, recycled waste gas is introduced into the combustion system in multiple stages, with the supply points corresponding to the high-temperature zone of the vertical combustion chamber. This effectively reduces the intensity of combustion within the vertical combustion chamber, improves the uniformity of heating in the vertical combustion chamber during operation, reduces the generation of nitrogen oxides, and lowers atmospheric pollutant emissions. Using coke oven gas for heating achieves low nitrogen oxide emissions and saves on tail gas treatment costs.

[0032] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A low-NOx combustion structure for a single-heat coke oven, characterized in that: The application relates to a coke oven battery, which comprises a small flue, a heat storage chamber, an inclined flue and a combustion chamber; the combustion chamber is composed of double fire flues; each two vertical fire flues form a pair of double fire flues; the upper parts of the ascending vertical fire flues and the descending vertical fire flues of the double fire flues are communicated through span holes; each vertical fire flue is composed of a coke oven gas supply inlet, ascending air multi-stage outlets, ascending return gas multi-stage outlets and descending waste gas multi-stage outlets; the return gas passages and the coke oven gas passages are arranged in the main wall of the heat storage chamber and directly pass through the underground part of the vertical fire flue; the coke oven gas passages and the return gas passages are opened during the ascending process and are closed during the descending process; the same stages of the ascending air multi-stage outlets and the descending waste gas multi-stage outlets have height differences; the ascending air multi-stage outlets comprise first, second and third ascending air outlets; the ascending return gas multi-stage outlets comprise first, second and third ascending return gas outlets; the descending waste gas multi-stage outlets comprise first, second and third descending waste gas outlets; the ascending air multi-stage outlets and the ascending return gas multi-stage outlets are arranged in the partition wall of the combustion chamber; the height of the first ascending return gas outlet is between the heights of the first and second ascending air outlets; the height of the second ascending return gas outlet is between the heights of the second and third ascending air outlets; the first ascending air outlet enters the bottom of the vertical fire flue from the heat storage chamber through a long inclined flue; the second and third ascending air outlets enter the bottom of the vertical fire flue from the heat storage chamber through short inclined flues; the descending waste gas first outlet enters the descending gas flow heat storage chamber through a short inclined flue; the descending waste gas second and third outlets enter the descending gas flow heat storage chamber through long inclined flues.

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