Pure oxygen combustion device combined with flue gas recirculation

Abstract

The utility model discloses a kind of pure oxygen combustion-supporting combustion devices combined with flue gas recirculation, comprising: kiln body, flue pipe fittings, liquid oxygen storage, oxygen control part, oxygen injection part and flue gas return pipe fittings;The flue pipe fittings one end is communicated with the flue gas export of kiln body;The liquid oxygen storage is used to store liquid oxygen, the input end of the oxygen control part is communicated with the output end of liquid oxygen storage, the output end of the oxygen control part is communicated with the input end of oxygen injection part, the output end of oxygen injection part extends to the inside of kiln body;The flue gas return pipe fittings one end is communicated with the lateral wall of flue pipe fittings, the other end of the flue gas return pipe fittings is communicated with the lateral wall of oxygen injection part or the lateral wall of kiln body.The utility model is combined by pure oxygen combustion-supporting and flue gas recirculation, give consideration to kiln combustion efficiency and low NOx emission, solve the problem of traditional air combustion-supporting NOx high, single flue gas return efficiency low.

Description

Technical Field

[0001] This utility model relates to the field of combustion devices for high-temperature kilns, and in particular to a pure oxygen-assisted combustion device that combines flue gas recirculation. Background Technology

[0002] Combustion devices for high-temperature kilns are widely used in lime kilns, cement kilns, heating furnaces, and non-ferrous metal kilns. Their core requirement is to control the emission of nitrogen oxides (NOx) during combustion while ensuring the combustion efficiency required for normal kiln processes, so as to meet industrial production and environmental protection requirements.

[0003] In existing technologies, most combustion devices use air as the combustion medium. Air contains a large amount of nitrogen, which easily reacts with oxygen to generate NOx under high-temperature combustion conditions, leading to excessive emissions. Some devices use flue gas recirculation technology to reduce NOx, but the recirculated low-temperature flue gas dilutes the concentration of combustion oxygen and lowers the temperature of the combustion zone, resulting in a decrease in combustion efficiency and making it difficult to meet the high-temperature process requirements of kilns. Neither of these two solutions can simultaneously achieve both combustion efficiency and low NOx emissions. Therefore, a pure oxygen-assisted combustion device that combines flue gas recirculation is proposed. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a pure oxygen-assisted combustion device that incorporates flue gas recirculation, thereby resolving the problems mentioned in the background section.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a pure oxygen-assisted combustion device combined with flue gas recirculation, comprising: Kiln body, flue pipe fittings, liquid oxygen storage components, oxygen control components, oxygen injection components, and flue gas return pipe fittings; One end of the flue pipe is connected to the flue gas outlet of the kiln body, and the other end is used to discharge part of the flue gas. The liquid oxygen storage device is used to store liquid oxygen. The input end of the oxygen control device is connected to the output end of the liquid oxygen storage device. The output end of the oxygen control device is connected to the input end of the oxygen injection device. The output end of the oxygen injection device extends into the interior of the kiln body. One end of the flue gas return pipe is connected to the side wall of the flue pipe, and the other end of the flue gas return pipe is connected to the side wall of the oxygen injection element or the side wall of the kiln body, so as to transport part of the flue gas in the flue pipe to the oxygen injection element or the kiln body. The oxygen control unit is used to control the amount of oxygen delivered from the liquid oxygen storage unit to the oxygen injection unit. The oxygen injection unit is used to mix the oxygen with the return flue gas delivered by the flue gas return pipe and then inject it into the kiln body. Through the coordinated operation of the above structures, the pure oxygen provided by the liquid oxygen storage unit is precisely regulated by the oxygen control unit and then enters the oxygen injection unit, where it is fully mixed with the return flue gas transported by the flue gas return pipe. This not only utilizes the characteristics of pure oxygen to improve the combustion efficiency within the kiln body, but also reduces the amount of NOx generated during combustion through flue gas return, achieving a synergistic balance between combustion efficiency and low pollution emissions. This effectively solves the problem that it is difficult to simultaneously meet the requirements of efficiency improvement and environmental protection in traditional combustion devices, ensuring the stable operation of the kiln body.

[0006] Preferably, it also includes a flue gas filter; the flue gas filter is arranged in series on the flue gas return pipe, the input end of the flue gas filter is connected to the end of the flue gas return pipe near the flue pipe, and the output end of the flue gas filter is connected to the end of the flue gas return pipe near the oxygen injection element or the kiln body, so as to filter impurity particles in the return flue gas.

[0007] Preferably, it also includes an oxygen preheating element; the oxygen preheating element is connected in series on the connecting pipeline between the oxygen control element and the oxygen injection element, the input end of the oxygen preheating element is connected to the output end of the oxygen control element, and the output end of the oxygen preheating element is connected to the input end of the oxygen injection element, so as to preheat the oxygen supplied by the oxygen control element to the oxygen injection element.

[0008] Preferably, it also includes a flue gas flow monitoring device; the flue gas flow monitoring device is installed on the flue gas return pipe, the flue gas flow monitoring device is internally connected to the flue gas return pipe, and the flue gas flow monitoring device is electrically connected to the oxygen control device to monitor the flue gas flow in the flue gas return pipe and transmit the flow signal to the oxygen control device.

[0009] Preferably, it further includes a gas-gas mixing chamber; the gas-gas mixing chamber is disposed at the connection position between the oxygen injection component and the flue gas return pipe, the first interface of the gas-gas mixing chamber is connected to the output end of the flue gas return pipe, the second interface of the gas-gas mixing chamber is connected to the input end of the oxygen injection component, and the third interface of the gas-gas mixing chamber is connected to the output end of the oxygen injection component, so as to realize the pre-mixing of oxygen and return flue gas in the gas-gas mixing chamber.

[0010] Preferably, it also includes a liquid oxygen pressure regulator; the liquid oxygen pressure regulator is connected in series on the connecting pipeline between the liquid oxygen storage device and the oxygen control device, the input end of the liquid oxygen pressure regulator is connected to the output end of the liquid oxygen storage device, and the output end of the liquid oxygen pressure regulator is connected to the input end of the oxygen control device, so as to regulate the initial pressure of the oxygen output by the liquid oxygen storage device.

[0011] In summary, compared with the prior art, this utility model provides a pure oxygen-assisted combustion device combined with flue gas recirculation, which has the following beneficial effects: This invention provides a pure oxygen source for combustion through a liquid oxygen storage device, and precisely controls the oxygen delivery volume with an oxygen control device, avoiding the NOx generation caused by the large amount of nitrogen involved in combustion in traditional air-assisted combustion. At the same time, the flue gas recirculation pipe recirculates part of the flue gas in the flue pipe back to the oxygen injection device or the kiln body, mixes with the oxygen in the oxygen injection device, and then injects it into the kiln body, realizing the combination of pure oxygen-assisted combustion and flue gas recirculation. It not only improves the combustion efficiency in the kiln body with pure oxygen, but also suppresses the formation of NOx at high temperatures through flue gas recirculation. It has the advantage of balancing combustion efficiency and low NOx emissions, and solves the problems of high NOx emissions in traditional air-assisted combustion devices and the tendency of single flue gas recirculation technology to reduce combustion temperature and affect process efficiency. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

[0013] Figure 2 This is a schematic diagram of the principle of the utility model.

[0014] Figure 3 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Kiln body; 2. Flue pipe fittings; 3. Liquid oxygen storage components; 4. Oxygen control components; 5. Oxygen injection components; 6. Flue gas return pipe fittings; 7. Flue gas filter components; 8. Oxygen preheating components; 9. Flue gas flow monitoring components; 10. Gas-gas mixing chamber components; 11. Liquid oxygen pressure regulating components. Detailed Implementation

[0016] This utility model provides a technical solution: a pure oxygen-assisted combustion device that combines flue gas recirculation. Example 1 Please see Figure 1 , Figure 2 and Figure 3 ,include: 1. Kiln body, 2. Flue pipe fittings, 3. Liquid oxygen storage device, 4. Oxygen control device, 5. Oxygen injection device, and 6. Flue gas return pipe fittings; One end of the flue pipe 2 is connected to the flue gas outlet of the kiln body 1, and the other end is used to discharge part of the flue gas. The liquid oxygen storage unit 3 is used to store liquid oxygen. The input end of the oxygen control unit 4 is connected to the output end of the liquid oxygen storage unit 3. The output end of the oxygen control unit 4 is connected to the input end of the oxygen injection unit 5. The output end of the oxygen injection unit 5 extends into the interior of the kiln body 1. One end of the flue gas return pipe 6 is connected to the side wall of the flue pipe 2, and the other end of the flue gas return pipe 6 is connected to the side wall of the oxygen injection component 5 or the side wall of the kiln body 1, so as to transport part of the flue gas in the flue pipe 2 to the oxygen injection component 5 or the kiln body 1. The oxygen control unit 4 is used to control the amount of oxygen delivered from the liquid oxygen storage unit 3 to the oxygen injection unit 5. The oxygen injection unit 5 is used to mix the oxygen with the return flue gas delivered by the flue gas return pipe 6 and then inject it into the kiln body 1. Through the synergy of the kiln body 1, the oxygen injection unit 5, etc., the combustion efficiency is improved and harmful emissions are reduced. The oxygen injection unit 5 is equipped with a mixing channel to enhance the mixing effect of oxygen and return flue gas.

[0017] This scheme: Liquid oxygen storage unit 3 stores liquid oxygen, and oxygen control unit 4 regulates the amount of oxygen delivered to oxygen injection unit 5; the flue gas generated by combustion in the kiln body 1 enters the flue pipe 2 through the flue gas outlet, and one end of the flue pipe 2 discharges part of the flue gas, while the other end is transported to the side wall of oxygen injection unit 5 or the side wall of kiln body 1 through flue gas return pipe 6 connected to the side wall; oxygen injection unit 5 is equipped with a mixing channel, which can fully mix the received oxygen with the return flue gas transported by flue gas return pipe 6, and then inject the mixed gas into kiln body 1 to assist combustion; the whole system, through the synergy of kiln body 1, oxygen injection unit 5, etc., not only improves combustion efficiency but also reduces harmful emissions.

[0018] Example 2 Please see Figure 3 It also includes a flue gas filter element 7; the flue gas filter element 7 is installed in series on the flue gas return pipe 6, the input end of the flue gas filter element 7 is connected to the end of the flue gas return pipe 6 near the flue pipe 2, and the output end of the flue gas filter element 7 is connected to the end of the flue gas return pipe 6 near the oxygen injection element 5 or the kiln body 1, so as to filter impurity particles in the return flue gas; the flue gas filter element 7 reduces impurities, protects the oxygen injection element 5 and the kiln body 1, and extends the service life of the device; the flue gas filter element 7 has a detachable filter screen structure, which is convenient for cleaning and maintenance; It also includes an oxygen preheating component 8; the oxygen preheating component 8 is connected in series on the connecting pipeline between the oxygen control component 4 and the oxygen injection component 5, the input end of the oxygen preheating component 8 is connected to the output end of the oxygen control component 4, and the output end of the oxygen preheating component 8 is connected to the input end of the oxygen injection component 5, so as to preheat the oxygen supplied by the oxygen control component 4 to the oxygen injection component 5; the oxygen preheating component 8 increases the oxygen temperature, enhances the combustion intensity in the kiln body 1, and saves energy; the oxygen preheating component 8 can utilize the waste heat of the flue pipe 2 for preheating; It also includes a flue gas flow monitoring device 9; the flue gas flow monitoring device 9 is installed on the flue gas return pipe 6, and is internally connected to the flue gas return pipe 6, and is electrically connected to the oxygen control device 4, so as to monitor the flue gas flow in the flue gas return pipe 6 and transmit the flow signal to the oxygen control device 4; the flue gas flow monitoring device 9 is linked with the oxygen control device 4 to accurately regulate the ratio and optimize the combustion state of the kiln body 1; the flue gas flow monitoring device 9 is an electronic flow meter with fast response speed; It also includes a gas-gas mixing chamber 10; the gas-gas mixing chamber 10 is located at the connection between the oxygen injection component 5 and the flue gas return pipe 6. The first interface of the gas-gas mixing chamber 10 is connected to the output end of the flue gas return pipe 6, the second interface of the gas-gas mixing chamber 10 is connected to the input end of the oxygen injection component 5, and the third interface of the gas-gas mixing chamber 10 is connected to the output end of the oxygen injection component 5, so as to realize the pre-mixing of oxygen and return flue gas in the gas-gas mixing chamber 10; the gas-gas mixing chamber 10 makes the mixed gas more uniform, improves the injection effect of the oxygen injection component 5, and ensures stable combustion of the kiln body 1; the gas-gas mixing chamber 10 is equipped with a guide plate to enhance the mixing effect; It also includes a liquid oxygen pressure regulator 11; the liquid oxygen pressure regulator 11 is connected in series on the connecting pipeline between the liquid oxygen storage unit 3 and the oxygen control unit 4. The input end of the liquid oxygen pressure regulator 11 is connected to the output end of the liquid oxygen storage unit 3, and the output end of the liquid oxygen pressure regulator 11 is connected to the input end of the oxygen control unit 4, so as to regulate the initial pressure of the oxygen output from the liquid oxygen storage unit 3; the liquid oxygen pressure regulator 11 stabilizes the input pressure, ensures the precise adjustment of the oxygen control unit 4, and improves the reliability of the system; the liquid oxygen pressure regulator 11 is an automatic regulating valve that can respond to pressure changes in real time.

[0019] In this scheme: the liquid oxygen in the liquid oxygen storage unit 3 is initially pressured by the liquid oxygen pressure regulator 11 and then enters the oxygen control unit 4; the oxygen is preheated by the oxygen preheater 8 (using the waste heat of the flue pipe 2) and then enters the gas-gas mixing chamber 10; the flue gas from the kiln body 1 enters the flue pipe 2, part of which passes through the flue gas return pipe 6, is first filtered by the flue gas filter 7, then the flow rate is measured by the flue gas flow monitoring unit 9 and a signal is transmitted to the oxygen control unit 4, and then enters the gas-gas mixing chamber 10; the guide plate in the gas-gas mixing chamber 10 premixes the oxygen with the return flue gas, and then injects it into the kiln body 1 through the oxygen injection unit 5, thereby improving combustion efficiency and stability.

Claims

1. A pure oxygen-assisted combustion device incorporating flue gas recirculation, characterized in that, include: The kiln body (1), flue pipe fittings (2), liquid oxygen storage fittings (3), oxygen control fittings (4), oxygen injection fittings (5), and flue gas return pipe fittings (6); One end of the flue pipe fitting (2) is connected to the flue gas outlet of the kiln body (1); The liquid oxygen storage device (3) is used to store liquid oxygen. The input end of the oxygen control device (4) is connected to the output end of the liquid oxygen storage device (3). The output end of the oxygen control device (4) is connected to the input end of the oxygen injection device (5). The output end of the oxygen injection device (5) extends into the interior of the kiln body (1). One end of the flue gas return pipe (6) is connected to the side wall of the flue pipe (2), and the other end of the flue gas return pipe (6) is connected to the side wall of the oxygen injection component (5) or the side wall of the kiln body (1). The oxygen control unit (4) is used to control the amount of oxygen delivered from the liquid oxygen storage unit (3) to the oxygen injection unit (5). The oxygen injection unit (5) is used to mix the oxygen with the flue gas reflux pipe (6) and then inject it into the kiln body (1).

2. The pure oxygen-assisted combustion device combined with flue gas recirculation according to claim 1, characterized in that: It also includes a flue gas filter (7); the flue gas filter (7) is connected in series on the flue gas return pipe (6), the input end of the flue gas filter (7) is connected to the end of the flue gas return pipe (6) near the flue pipe (2), and the output end of the flue gas filter (7) is connected to the end of the flue gas return pipe (6) near the oxygen injection element (5) or the kiln body (1).

3. The pure oxygen-assisted combustion device combined with flue gas recirculation according to claim 1, characterized in that: It also includes an oxygen preheating element (8); the oxygen preheating element (8) is connected in series on the connecting pipeline between the oxygen control element (4) and the oxygen injection element (5), the input end of the oxygen preheating element (8) is connected to the output end of the oxygen control element (4), and the output end of the oxygen preheating element (8) is connected to the input end of the oxygen injection element (5).

4. The pure oxygen-assisted combustion device combined with flue gas recirculation according to claim 1, characterized in that: It also includes a flue gas flow monitoring device (9); the flue gas flow monitoring device (9) is installed on the pipeline of the flue gas return pipe (6), the flue gas flow monitoring device (9) is internally connected to the flue gas return pipe (6), and the flue gas flow monitoring device (9) is electrically connected to the oxygen control device (4).

5. A pure oxygen-assisted combustion device combined with flue gas recirculation according to claim 1, characterized in that: It also includes a gas-gas mixing chamber (10); the gas-gas mixing chamber (10) is located at the connection position between the oxygen injection component (5) and the flue gas return pipe (6), the first interface of the gas-gas mixing chamber (10) is connected to the output end of the flue gas return pipe (6), the second interface of the gas-gas mixing chamber (10) is connected to the input end of the oxygen injection component (5), and the third interface of the gas-gas mixing chamber (10) is connected to the output end of the oxygen injection component (5).

6. The pure oxygen-assisted combustion device combined with flue gas recirculation according to claim 1, characterized in that: It also includes a liquid oxygen pressure regulator (11); the liquid oxygen pressure regulator (11) is connected in series on the connecting pipeline between the liquid oxygen storage unit (3) and the oxygen control unit (4), the input end of the liquid oxygen pressure regulator (11) is connected to the output end of the liquid oxygen storage unit (3), and the output end of the liquid oxygen pressure regulator (11) is connected to the input end of the oxygen control unit (4).

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