A pure oxygen flue gas recirculation burner

Abstract

The present invention belongs to the technical field of combustion of metallurgical industrial furnaces, and relates to a pure oxygen flue gas recirculation burner, which includes a recirculation flue gas pipe and a combustion chamber arranged inside the recirculation flue gas pipe. The combustion chamber is communicated with the recirculation flue gas pipe; it also includes a gas pipe and an oxygen pipe. One end of the gas pipe is arranged outside the recirculation flue gas pipe, and the other end is arranged inside the combustion chamber. The oxygen pipe includes an ignition oxygen pipe and a premixed oxygen pipe. Both the ignition oxygen pipe and the premixed oxygen pipe pass through the recirculation flue gas pipe and are communicated with the combustion chamber. The present invention can form a stable flame in the combustion chamber, enable oxygen and flue gas to be fully mixed to avoid local combustion high temperature, and apply the staged combustion technology to ensure the uniformity of the flame temperature. The burner of the present invention can apply the pure oxygen combustion technology to steel industrial furnaces, which is of great significance for saving fuel, reducing pollutant emissions, and achieving carbon emission reduction.

Description

Technical Field

[0001] The present invention belongs to the technical field of combustion of metallurgical industrial furnaces, and relates to a pure oxygen flue gas circulation burner. Background Art

[0002] The iron and steel industry is one of the major energy consumers and main sources of air pollutants. Currently, air-assisted combustion is basically used for heating in iron and steel industrial furnaces, but there are problems such as high pollutant emissions, large flue gas emissions, and great difficulty in carbon emission reduction. Moreover, it is very difficult to significantly improve the thermal efficiency of the furnace under the existing technology. The pure oxygen combustion technology can greatly reduce the flue gas volume and pollutant emissions, reduce the heat loss carried away by the exhaust gas, and at the same time increase the content of CO2 and H2O in the flue gas, which is of great significance for carbon capture and utilization. It is a clean combustion technology and is widely used in industries such as non-ferrous metals and glass. The temperature of pure oxygen combustion is high. Directly applying it to iron and steel industrial furnaces will cause problems such as overburning and uneven temperature of the heated materials. Therefore, combining flue gas circulation with pure oxygen combustion technology is one of the effective ways to apply this technology to iron and steel industrial furnaces. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a pure oxygen flue gas circulation burner, enabling the pure oxygen combustion technology to be used in iron and steel industrial furnaces, solving the problem of excessively high local temperature in pure oxygen combustion, reducing pollutant emissions, and saving energy.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A pure oxygen flue gas circulation burner includes a circulating flue gas pipe and a combustion chamber arranged inside the circulating flue gas pipe. The combustion chamber is communicated with the circulating flue gas pipe; it further includes a gas pipe and an oxygen pipe. One end of the gas pipe is arranged outside the circulating flue gas pipe, and the other end is arranged inside the combustion chamber. The oxygen pipe includes an ignition oxygen pipe and a premixed oxygen pipe. Both the ignition oxygen pipe and the premixed oxygen pipe pass through the circulating flue gas pipe and are communicated with the combustion chamber.

[0006] Optionally, a flue gas outlet plate is provided at the position where the combustion chamber is communicated with the circulating flue gas pipe. The flue gas outlet plate is provided with flue gas swirl spray holes, and the swirl angle is 30 - 60 degrees.

[0007] Optionally, the oxygen pipe further includes a secondary oxygen pipe arranged outside the combustion chamber.

[0008] Optionally, the ignition oxygen pipe is provided with an ignition oxygen spray hole and a premixed oxygen spray hole inside the combustion chamber. The premixed oxygen spray hole and the ignition oxygen spray hole are arranged in sequence along the oxygen flow direction inside the ignition oxygen pipe.

[0009] Optionally, the included angle between the ignition oxygen nozzle and the center line of the pure oxygen flue gas recirculation burner is 30 - 60 degrees, and the ignition oxygen nozzle faces the direction of the center line of the pure oxygen flue gas recirculation burner.

[0010] Optionally, the distance between the ignition oxygen nozzle and the flue gas outlet plate is 50 - 150 mm.

[0011] Optionally, the premixed oxygen pipe is also provided with premixed oxygen nozzles, and the axial distance from the ignition oxygen nozzles is 50 - 150 mm; the direction of the premixed oxygen nozzles is perpendicular to the axial direction of the premixed oxygen pipe or the ignition oxygen pipe where they are located.

[0012] Optionally, the outlet of the gas pipe is provided with a plurality of gas nozzles. The gas nozzles are located in the combustion chamber. The included angle between the gas nozzles and the center line of the pure oxygen flue gas recirculation burner is 30 - 60 degrees, and the axial distance between the gas nozzles and the flue gas outlet plate is 50 - 150 mm.

[0013] Optionally, one ignition oxygen pipe is provided, at least one premixed oxygen pipe is provided, and the oxygen amount of the ignition oxygen nozzles accounts for 10% - 20% of the total required oxygen amount.

[0014] Optionally, at least one secondary oxygen pipe is provided. The outlet of the secondary oxygen pipe is located outside the circulating flue gas pipe, and the oxygen amount of the secondary oxygen pipe accounts for 20% - 50% of the total required oxygen amount.

[0015] The beneficial effects of the present invention are as follows:

[0016] The burner structure of the present invention can form a stable ignition source, enable sufficient mixing of oxygen and flue gas to avoid local combustion high temperature, and apply the staged combustion technology to ensure the uniformity of the flame temperature, so that the pure oxygen combustion technology can be fully applied to the steel industry furnace.

[0017] Other advantages, objectives and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, wherein:

[0019] Figure 1 is a schematic structural diagram of the present invention;

[0020] Figure 2 is a schematic diagram of the positions of the premixed oxygen nozzles and the ignition oxygen nozzles;

[0021] Figure 3 It is a structural schematic diagram of the flue gas outlet plate.

[0022] Reference numerals in the drawings: gas pipe 1, gas injection hole 11, circulating flue gas pipe 2, flue gas outlet plate 21, flue gas injection hole 22, oxygen pipe 3, ignition oxygen pipe 31, premixed oxygen pipe 32, secondary oxygen pipe 33, ignition oxygen injection hole 34, premixed oxygen injection hole 35, secondary oxygen injection hole 36, combustion chamber 4. Specific embodiments

[0023] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0024] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0025] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0026] Please refer to Figures 1 to 3 , which is a pure oxygen flue gas recirculation burner, composed of a gas pipe 1, a circulating flue gas pipe 2, an oxygen pipe 3, and a combustion chamber 4. The oxygen pipe 3 is divided into an ignition oxygen pipe 31, a premixed oxygen pipe 32, and a secondary oxygen pipe 33. The gas pipe 1, the circulating flue gas pipe 2, the ignition oxygen pipe 31, and the premixed oxygen pipe 32 are connected to the combustion chamber 4. The gas pipe 1 is located on the center line of the burner. The ignition oxygen pipe 31 and the premixed oxygen pipe 32 are located outside the gas pipe 1, and the secondary oxygen pipe 33 is located outside the combustion chamber 4.

[0027] At the front end of the circulating flue gas pipe 2, there is a flue gas outlet plate 21. The flue gas outlet plate 21 is located at the inlet of the combustion chamber 4. There are flue gas spray holes 22 on the flue gas outlet plate 21. After the recirculated flue gas enters the flue gas pipe, it enters the combustion chamber through the flue gas spray holes. There are multiple flue gas spray holes 22, which are of a swirl hole structure, and the swirl angle is 30 - 60 degrees.

[0028] The gas pipe 1 is arranged on the burner center line, and there are multiple gas spray holes 11 at its outlet. The gas spray holes are located inside the combustion chamber 4. The included angle α between the gas spray holes 11 and the burner center line is 30 - 60 degrees, and the axial distance L3 between the gas spray holes and the flue gas outlet plate is 50 - 150 mm.

[0029] The ignition oxygen pipe 21 is located outside the gas pipe 1, passes through the circulating flue gas pipe 2 and the flue gas outlet plate 21, and there are an ignition oxygen spray hole 34 and a premixed oxygen spray hole 35 at its outlet. The ignition oxygen spray hole 34 and the premixed oxygen spray hole 35 are located inside the combustion chamber 4. The ignition oxygen spray hole 34 is at the very front end of the outlet of the ignition oxygen pipe 31, and the distance L2 from the flue gas outlet plate 21 is 50 - 150 mm. The included angle β between the ignition oxygen spray hole 34 and the burner center line is 30 - 60 degrees, and it faces the direction of the burner center line. There is 1 ignition oxygen pipe, and the oxygen quantity of the ignition oxygen spray hole accounts for 10% - 20% of the oxygen quantity required by the burner.

[0030] When the burner works, the gas passes through the gas pipe 1 and then sprays out from the gas spray port 11, and part of the oxygen sprays out through the ignition oxygen spray hole 34. Since both the gas and the ignition oxygen form certain included angles α and β with the burner center line, the two are ignited after contacting in the combustion chamber, forming a stable ignition source to ensure the stability of the burner flame.

[0031] The premixed oxygen pipe 32 is located on the outer ring of the gas pipe 1, passes through the circulating flue gas pipe 2 and the flue gas outlet plate 21, and there is a premixed oxygen spray hole 35 at its outlet. The premixed oxygen spray hole 35 is located inside the combustion chamber 4. Both the ignition oxygen pipe 31 and the premixed oxygen pipe 32 have premixed oxygen spray holes 35. The premixed oxygen spray hole 35 is behind the ignition oxygen spray hole 34, and the axial distance L1 from the ignition oxygen spray hole 34 is 50 - 150 mm. The direction of the premixed oxygen spray hole 35 is perpendicular to the axes of the ignition oxygen pipe 31 and the premixed oxygen pipe 32. There are 1, 2 or more premixed oxygen pipes 32, and the premixed oxygen quantity accounts for 30% - 70% of the oxygen quantity required by the burner.

[0032] After the flue gas enters the circulating flue gas pipe 2, it enters the combustion chamber through the flue gas spray holes 22 on the flue gas outlet plate 21. Part of the oxygen enters the combustion chamber through the premixed oxygen spray hole 35. The two are fully mixed in the combustion chamber, and then mixed and burned with the gas sprayed out from the gas spray hole 11. The premixing of the circulating flue gas and oxygen effectively reduces the oxygen content and avoids local high temperature in the combustion chamber 4.

[0033] The secondary oxygen pipe 33 is located outside the combustion chamber 4 and passes through the circulating flue gas pipe 2. The secondary oxygen injection holes 36 are located outside the circulating flue gas pipe 2. One, two or more secondary oxygen pipes can be provided, and the amount of secondary oxygen accounts for 20%-50% of the total amount of oxygen required by the burner.

[0034] The ignition oxygen, premixed oxygen, circulating flue gas, and oxygen are mixed and burned in the combustion chamber 4, and then mixed and burned with the secondary oxygen after being ejected from the combustion chamber 4, forming staged combustion to improve the uniformity of the flame temperature.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A pure oxygen flue gas recirculation burner, characterized in that: It includes a circulating flue gas pipe and a combustion chamber arranged inside the circulating flue gas pipe, and the combustion chamber is communicated with the circulating flue gas pipe; it also includes a gas pipe and an oxygen pipe. One end of the gas pipe is arranged outside the circulating flue gas pipe, and the other end is arranged inside the combustion chamber. The oxygen pipe includes an ignition oxygen pipe and a premixed oxygen pipe, and both the ignition oxygen pipe and the premixed oxygen pipe pass through the circulating flue gas pipe and are communicated with the combustion chamber; The oxygen pipe also includes a secondary oxygen pipe arranged outside the combustion chamber; the ignition oxygen pipe is provided with an ignition oxygen injection hole and a premixed oxygen injection hole located inside the combustion chamber, and the premixed oxygen injection hole and the ignition oxygen injection hole are arranged in sequence along the oxygen flow direction inside the ignition oxygen pipe; the included angle between the ignition oxygen injection hole and the center line of the pure oxygen flue gas circulating burner is 30-60 degrees, and the ignition oxygen injection hole faces the center line direction of the pure oxygen flue gas circulating burner; the premixed oxygen pipe is also provided with a premixed oxygen injection hole, and the axial distance from the ignition oxygen injection hole is 50-150mm; the direction of the premixed oxygen injection hole is perpendicular to the axis of the premixed oxygen pipe or the ignition oxygen pipe where it is located.

2. The pure oxygen flue gas recirculation burner according to claim 1, characterized in that: A flue gas outlet plate is arranged at the position where the combustion chamber is communicated with the circulating flue gas pipe, and the flue gas outlet plate is provided with a flue gas swirl injection hole, and the swirl angle is 30-60 degrees.

3. The pure oxygen flue gas recirculation burner according to claim 2, characterized in that: The distance between the ignition oxygen injection hole and the flue gas outlet plate is 50-150mm.

4. The pure oxygen flue gas recirculation burner according to claim 2, characterized in that: A plurality of gas injection holes are arranged at the outlet of the gas pipe, the gas injection holes are located inside the combustion chamber, the included angle between the gas injection holes and the center line of the pure oxygen flue gas circulating burner is 30-60 degrees, and the axial distance between the gas injection holes and the flue gas outlet plate is 50-150mm.

5. The pure oxygen flue gas recirculation burner according to claim 1, characterized in that: One ignition oxygen pipe is arranged, at least one premixed oxygen pipe is arranged, and the oxygen amount of the ignition oxygen injection hole accounts for 10%-20% of the total required oxygen amount.

6. The pure oxygen flue gas recirculation burner according to claim 1, characterized in that: At least one secondary oxygen pipe is arranged, the outlet of the secondary oxygen pipe is located outside the circulating flue gas pipe, and the oxygen amount of the secondary oxygen pipe accounts for 20%-50% of the total required oxygen amount.

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