Glass furnace using ammonia oxygen-rich combustion method for heating

Abstract

The application discloses a glass furnace adopting an ammonia oxygen-enriched combustion method for heating, and belongs to the field of glass furnaces, and comprises an oxygen pipeline, an air distributor, a carbon dioxide pipeline, a carbon dioxide detector, a cyclone, an ammonia gas pipeline, a mixing pipeline, a fire damper, an igniter, a combustion melting chamber, a carbon dioxide capturing device and a nitrogen oxide treatment device. The air distributor is installed at a branch opening of the oxygen pipeline, the cyclone is installed in the mixing pipeline, the fire damper is installed at the end of the mixing pipeline and the end of one branch of the oxygen pipeline, and the carbon dioxide capturing device and the nitrogen oxide treatment device are sequentially installed behind the outlet of the combustion melting chamber. The preheated ammonia gas is introduced into the combustion melting chamber through the central ammonia gas pipeline and is wrapped by the low-temperature oxygen and carbon dioxide mixed gas to realize two-stage combustion. The carbon dioxide is used to replace nitrogen, a large amount of thermal nitrogen oxides is reduced, the radiation heat transfer in the combustion melting chamber is enhanced, and the heating effect is more ideal.

Description

Technical Field

[0001] This invention belongs to the field of glass furnaces and kilns, and relates to a glass furnace and kiln that uses ammonia-oxygen-enriched combustion for heating. Background Technology

[0002] To achieve carbon neutrality, it is essential to prioritize addressing the primary challenge, focusing on decarbonizing the industrial sector—a major energy consumer. Within the industrial sector, over 20% of energy is used to generate heat in industrial furnaces for processing materials such as glass. These furnaces primarily rely on natural gas as fuel, posing a significant challenge to emissions reduction efforts.

[0003] Ammonia, as an ideal carbon-free alternative fuel, is widely used in power generation, transportation, and industrial processing. Its complete combustion produces only water and nitrogen, thus not exacerbating the greenhouse effect. However, the chemical properties of ammonia limit its development as a novel fuel. For example, ammonia has a lower flame speed and temperature than traditional hydrocarbon fuels, and because its flame does not contain carbon dioxide, its radiative heat transfer capacity is weak. This makes it difficult to directly apply ammonia to industrial equipment requiring high-temperature smelting, such as glass furnaces.

[0004] Compared to traditional air combustion, oxygen-enriched combustion technology has a higher flame temperature and combustion speed, a lower ignition temperature and burnout time, and produces less flue gas and a corresponding reduction in nitrogen oxides. Summary of the Invention

[0005] In light of the above background technology, this invention proposes a glass furnace that uses ammonia-oxygen-enriched combustion for heating. This glass furnace uses ammonia as fuel and pure oxygen as a combustion aid, and is heated via a swirling, non-premixed oxygen-enriched combustion method.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0007] A glass furnace using ammonia-oxygen-enriched combustion for heating includes an oxygen pipeline, a carbon dioxide pipeline, an ammonia pipeline, a mixing pipeline, a combustion melting chamber, a carbon dioxide capture device, and a nitrogen oxide treatment device.

[0008] The oxygen and carbon dioxide pipelines converge and are connected to the ammonia pipeline at the same location via a mixing pipeline to the inlet of the combustion melting chamber. The outlet of the combustion melting chamber is sequentially connected to a carbon dioxide capture device and a nitrogen oxide treatment device. The middle section of the oxygen pipeline is connected to the rear middle section of the combustion melting chamber via a branch of the oxygen pipeline, and the middle section of the carbon dioxide pipeline is connected to the carbon dioxide capture device via a branch of the carbon dioxide pipeline.

[0009] In the above technical solution, the glass furnace also includes an air distributor, which is located at the branch point of the oxygen pipeline.

[0010] In the above technical solution, the glass furnace also includes a carbon dioxide detector, which is installed at the beginning of a branch of the carbon dioxide pipeline.

[0011] In the above technical solution, the glass furnace also includes a hydrocyclone, which is located behind the junction of the oxygen pipeline and the carbon dioxide pipeline on the mixing pipeline.

[0012] In the above technical solution, the glass furnace further includes a first flame arrester, which is located at the end of the ammonia pipeline and the mixing pipeline.

[0013] In the above technical solution, the glass furnace further includes a second flame arrester, which is located at the end of a branch of the oxygen pipeline.

[0014] In the above technical solution, the glass furnace also includes an igniter, which is located in the combustion and melting chamber on the side close to the first flame arrester.

[0015] In the above technical solution, the inner wall of the ammonia pipeline has been pre-treated with anti-corrosion measures.

[0016] In the above technical solution, the ammonia gas introduced into the ammonia pipeline is preheated to above 600K.

[0017] In the above technical solution, the volume ratio of oxygen to carbon dioxide in the mixing pipeline is 3:2.

[0018] Beneficial effects:

[0019] This invention proposes a glass furnace using an ammonia-oxygen-enriched combustion heating method, comprising an oxygen pipeline, an air distributor, a carbon dioxide pipeline, a carbon dioxide detector, a cyclone separator, an ammonia pipeline, a mixing pipeline, a first flame arrester, an igniter, a second flame arrester, a combustion melting chamber, a carbon dioxide capture device, and a nitrogen oxide treatment device. During operation, the input ammonia is preheated. Most of the oxygen and carbon dioxide form a new mixture in the mixing pipeline, exhibiting a slightly fuel-rich combustion state in the inlet section of the combustion melting chamber. This significantly enhances the propagation speed and adiabatic temperature of the ammonia flame, allowing the combustion melting chamber to reach the required operating temperature. The remaining oxygen is fed into the combustion melting chamber via a branch of the oxygen pipeline, exhibiting a lean combustion state in the rear section to ensure complete combustion of the introduced ammonia. Using carbon dioxide instead of nitrogen not only reduces the generation of a large amount of thermal nitrogen oxides but also enhances the radiative heat transfer process within the combustion melting chamber, resulting in a more ideal heating effect. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the flame arrester in this invention;

[0022] In the diagram: 1 is the oxygen pipeline, 2 is the air distributor, 3 is the carbon dioxide pipeline, 4 is the carbon dioxide detector, 5 is the cyclone separator, 6 is the ammonia pipeline, 7 is the mixing pipeline, 8 is the first flame arrester, 9 is the igniter, 10 is the second flame arrester, 11 is the combustion melting chamber, 12 is the carbon dioxide capture device, and 13 is the nitrogen oxide treatment device. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example

[0025] A glass furnace using ammonia-oxygen-enriched combustion heating method includes an oxygen pipeline 1, an air distributor 2, a carbon dioxide pipeline 3, a carbon dioxide detector 4, a cyclone separator 5, an ammonia pipeline 6, a mixing pipeline 7, a first flame arrester 8, an igniter 9, a second flame arrester 10, a combustion melting chamber 11, a carbon dioxide capture device 12, and a nitrogen oxide treatment device 13.

[0026] The end of the oxygen pipeline 1 is connected to the starting section of the mixing pipeline 7, and the middle section of the pipeline is connected to the rear section of the combustion melting chamber 11 via a branch of the oxygen pipeline; the end of the carbon dioxide pipeline 3 is connected to the starting section of the mixing pipeline 7, and the middle section of the pipeline is connected to the carbon dioxide capture device 12 via a branch of the carbon dioxide pipeline; the air distributor 2 is located at the branch of the oxygen pipeline 1, the carbon dioxide detector 4 is located at the starting section of the branch of the carbon dioxide pipeline, and the cyclone separator 5 is located behind the junction of the oxygen pipeline 1 and the carbon dioxide pipeline 3 on the mixing pipeline 7; the first flame arrester 8 and the second flame arrester 10 are respectively located at the ends of the ammonia pipeline 6 and the mixing pipeline 7, and at the end of the branch of the oxygen pipeline; the igniter 9 is located inside the combustion melting chamber 11 on the side close to the first flame arrester 8; the carbon dioxide capture device 12 is located behind the outlet of the combustion melting chamber 11, and the nitrogen oxide treatment device 13 is located behind the carbon dioxide capture device 12.

[0027] In this embodiment, the oxygen pipeline 1 has one inlet and two outlets. The inner wall of the pipeline has been pre-treated with rust prevention to prevent the circulating oxygen from corroding the pipeline.

[0028] In this embodiment, the air distributor 2 keeps most of the oxygen in the original oxygen pipeline 1 in the original channel, distributes the remaining oxygen to the oxygen branch pipeline, and finally introduces it into the middle and rear part of the combustion melting chamber 11.

[0029] In this embodiment, the carbon dioxide pipeline 3 has two inlets and one outlet, with the carbon dioxide supplied from an external gas source and captured by a carbon dioxide capture device.

[0030] In this embodiment, the carbon dioxide detector 4 can monitor the amount of carbon dioxide captured and recovered, and then adjust the amount of carbon dioxide supplied externally to ensure that the total amount of carbon dioxide supplied remains unchanged.

[0031] In this embodiment, the cyclone separator 5 can fully mix the introduced oxygen and carbon dioxide to form a new mixed gas, wherein the volume ratio of oxygen to carbon dioxide is 3:2, that is, the volume fraction of oxygen is 60%.

[0032] In this embodiment, the inner wall of the ammonia pipeline 6 has been pre-treated with anti-corrosion measures to prevent it from reacting with the introduced ammonia gas, and the introduced ammonia gas is preheated to above 600K.

[0033] In this embodiment, the carbon dioxide capture device 12 can capture a large amount of unreacted carbon dioxide at the outlet of the combustion melting chamber and feed it into a branch of the carbon dioxide pipeline for recycling.

[0034] In this embodiment, the nitrogen oxide treatment device 13 reduces the nitrogen oxides in the exhaust gas to meet the emission standards before discharging it.

[0035] In this embodiment, the introduced ammonia gas is kept in a slightly rich combustion state with an equivalence ratio of 1.05-1.20 at the outlet of ammonia gas pipeline 6, and the global equivalence ratio is kept at a chemical equivalence ratio of 1 to achieve a two-stage combustion mode of "rich combustion + lean combustion", ensuring that the amount of unburned ammonia gas and generated nitrogen oxides in the combustion melting chamber 11 is minimized.

[0036] In this embodiment, oxygen-enriched combustion reduces the difficulty of preheating ammonia combustion and increases the speed and temperature of the ammonia flame in the combustion melting chamber 11, making it suitable for industrial equipment such as glass furnaces that require high-temperature melting.

[0037] In this embodiment, the use of a combination of "oxygen + carbon dioxide" gas instead of the widely used combination of "oxygen + nitrogen" air can avoid the excessively high temperature in the combustion melting chamber 11 from oxidizing a large amount of nitrogen gas into thermal nitrogen oxides; at the same time, carbon dioxide, as a triatomic gas, has strong radiation and absorption capabilities, which can transfer the heat released from the ammonia flame to the entire combustion melting chamber 11, promoting the uniformity of heat transfer.

[0038] like Figure 1 As shown, this embodiment provides a glass furnace heated by an ammonia-oxygen-enriched combustion method. The volume ratio of the supplied oxygen, carbon dioxide, and ammonia is 3:2:4. The air distributor 2 keeps most of the oxygen in the original channel and distributes the remaining oxygen to an oxygen branch pipeline, which is then introduced into the combustion and melting chamber. This ensures that the introduced ammonia gas maintains a slightly enriched combustion state with an equivalence ratio of 1.05-1.20 at the ammonia pipeline outlet, and maintains a global equivalence ratio of 1 in the combustion and melting chamber, thus implementing a two-stage combustion process of rich and lean.

[0039] like Figure 1 As shown, the swirling number of the hydrocyclone 5 is 0.8, which can generate a strong turbulent mixing intensity, allowing the introduced oxygen and carbon dioxide to be fully and uniformly mixed.

[0040] like Figure 1 As shown, the ammonia pipeline 6 passes through the center of the mixing pipeline 7, and the original swirling flame will become a thin flame. The mixture of oxygen and carbon dioxide at a lower temperature surrounds the preheated ammonia, isolating the ammonia from the high-temperature zone, making the pyrolysis reaction the main pathway for ammonia consumption. The reducing atmosphere in the combustion melting chamber 11 is strong, and the concentration of nitrogen oxides at the outlet of the combustion melting chamber 11 is significantly reduced.

[0041] like Figure 2 As shown, the flame arrester contains many small channels that allow the mixed gas to flow, but the retreating flame is divided into many thin flames by the flame arrester; the heat generated by combustion in the channels is much less than the heat dissipated to the channel walls, and the flame temperature drops sharply; when the temperature drops to a certain level, the flame will be extinguished in the flame arrester channels.

[0042] The working principle of a glass furnace using ammonia-oxygen-enriched combustion for heating is as follows:

[0043] In operation, the ammonia gas is preheated, and most of the oxygen in the oxygen pipeline is mixed with carbon dioxide to form a slightly fuel-rich combustion structure in the inlet section of the combustion melting chamber. This significantly enhances the propagation speed and adiabatic temperature of the ammonia flame, allowing the combustion melting chamber to reach the required operating temperature. The remaining oxygen is sent to the rear of the combustion melting chamber via a branch of the oxygen pipeline to implement a lean combustion structure, ensuring the complete combustion of the introduced ammonia gas. Replacing the original nitrogen with carbon dioxide not only reduces the generation of a large amount of thermal nitrogen oxides but also enhances the radiative heat transfer process in the combustion melting chamber, resulting in a more ideal heating effect.

[0044] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A glass furnace using an ammonia-oxygen-enriched combustion method for heating, characterized in that: It includes oxygen pipelines, carbon dioxide pipelines, ammonia pipelines, mixing pipelines, combustion melting chambers, carbon dioxide capture devices, and nitrogen oxide treatment devices; The oxygen and carbon dioxide pipelines converge and are connected to the ammonia pipeline at the same location via a mixing pipeline to the inlet of the combustion melting chamber. The outlet of the combustion melting chamber is sequentially connected to a carbon dioxide capture device and a nitrogen oxide treatment device. The middle part of the oxygen pipeline is connected to the middle and rear part of the combustion melting chamber via a branch of the oxygen pipeline, and the middle part of the carbon dioxide pipeline is connected to the carbon dioxide capture device via a branch of the carbon dioxide pipeline. The ammonia pipeline passes through the center of the mixing pipeline. The preheated ammonia is enveloped by a mixture of oxygen and carbon dioxide at a lower temperature, which isolates the ammonia from the high-temperature zone. The volume ratio of the supplied oxygen, carbon dioxide, and ammonia is 3:2:

4. The air distributor keeps a portion of the oxygen in the original channel and distributes the remaining oxygen to an oxygen branch pipeline, which is then introduced into the combustion and melting chamber. This ensures that the ammonia gas maintains an equivalence ratio of 1.05-1.20 at the ammonia pipeline outlet and a global equivalence ratio of 1 in the combustion and melting chamber, thus achieving two-stage combustion with both rich and lean components.

2. A glass furnace furnace using ammonia-oxygen-enriched combustion heating as described in claim 1, characterized in that: The glass furnace also includes an air distributor, which is located at the branch point of the oxygen pipeline.

3. A glass furnace furnace using ammonia-oxygen-enriched combustion heating method according to claim 1, characterized in that: The glass furnace also includes a carbon dioxide detector, which is installed at the beginning of a branch of the carbon dioxide pipeline.

4. A glass furnace furnace using ammonia-oxygen-enriched combustion heating method according to claim 1, characterized in that: The glass furnace also includes a hydrocyclone, which is located behind the junction of the oxygen pipeline and the carbon dioxide pipeline on the mixing pipeline.

5. A glass furnace using ammonia-oxygen-enriched combustion for heating according to claim 1, characterized in that: The glass furnace also includes a first flame arrester, which is located at the end of the ammonia pipeline and the mixing pipeline.

6. A glass furnace using ammonia-oxygen-enriched combustion for heating according to claim 1, characterized in that: The glass furnace also includes a second flame arrester, which is located at the end of a branch of the oxygen pipeline.

7. A glass furnace furnace using ammonia-oxygen-enriched combustion heating method according to claim 1, characterized in that: The glass furnace also includes an igniter, which is located in the combustion and melting chamber on the side near the first flame arrester.

8. A glass furnace using ammonia-oxygen-enriched combustion for heating according to claim 1, characterized in that: The inner wall of the ammonia pipeline has been pre-treated with anti-corrosion measures.

9. A glass furnace furnace using ammonia-oxygen-enriched combustion heating method according to claim 1, characterized in that: The ammonia gas introduced into the ammonia pipeline is preheated to over 600K.

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