Multi-layer pure oxygen burner for steel ladle and tundish roaster

Abstract

The utility model provides a multi-layer pure oxygen burner for a steel ladle tundish roaster, which relates to the technical field of pure oxygen burners and comprises a gas inlet, the top of the gas inlet is communicated with a gas cavity, an automatic ignition switch is arranged at the top of the gas cavity, an air inlet is arranged at the top of the gas cavity, and an air outlet is arranged at the top of the air inlet. And an air cavity is formed in the right side of the top of the gas cavity. Through the arrangement of the fuel gas inlet, the automatic ignition switch and other parts, the energy-saving burner has the advantages that the burning speed is increased, complete burning is promoted, the ignition temperature and the burnout temperature of fuel are reduced, the gas displacement after burning is reduced, the heat utilization rate is increased, the energy-saving effect is obvious, and the coefficient of excess air is reduced, so that energy is saved, and consumption is reduced; and through the arrangement of the one-way mechanism, gas can only be discharged in one direction, so that the overall use stability and safety of the device are effectively improved, and a user can use the device conveniently.

Description

Technical Field

[0001] This utility model relates to the field of pure oxygen burner technology, specifically to a multi-level pure oxygen burner for use in steel ladle tundish baking machines. Background Technology

[0002] With the development of the steel industry, steel producers are paying increasing attention to steel quality and production costs, thus placing higher demands on the baking temperature and energy consumption of steel ladles and tundishes. On the one hand, it requires baking the steel ladle to a high temperature while ensuring temperature uniformity; on the other hand, it requires low energy consumption, minimal environmental pollution, and even the use of low-calorific-value fuels.

[0003] Currently, the ladle baking ovens commonly used by steel companies both domestically and internationally are mainly direct-vent type, metal self-preheating type, and regenerative type. The main problems with direct-vent and metal preheating types are high energy consumption, long baking time, low baking temperature, high exhaust gas temperature, and poor baking quality. Regenerative types suffer from high maintenance requirements and a high failure rate; many companies eventually shut down the regenerative function and switch to conventional combustion baking. This makes it difficult to bear and meet the ever-increasing energy costs and increasingly stringent environmental emission requirements.

[0004] Therefore, pure oxygen combustion technology emerged to solve the above problems. Utility Model Content

[0005] This invention provides a multi-layer pure oxygen burner for a steel ladle tundish baking oven, which solves the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0007] This utility model provides a multi-layer pure oxygen burner for a steel ladle tundish baking oven, comprising: a gas inlet, a gas chamber connected to the top of the gas inlet, an automatic ignition switch provided at the top of the gas chamber, an air inlet provided at the top of the gas chamber, an air chamber provided on the right side of the top of the gas chamber, the air inlet and the air chamber being interconnected, a mounting base plate fixedly connected to the right side of the air chamber, a burner nozzle provided on the right side of the mounting base plate, a gas nozzle provided on the right side of the gas chamber, a central air supply provided on the right side of the gas chamber, oxygen nozzles provided at both the top and bottom of the gas chamber, and an oxygen inlet connected to the bottom of the gas chamber.

[0008] Through the above technical solution, air enters the burner through the air inlet, is rectified within the cavity, and is then ejected in two parts: a central airflow and an annular airflow. On both sides of the gas nozzle, oxygen enters the burner through the inlet pipe, is rectified within the cavity, and is ejected through the oxygen nozzle. The oxygen nozzle consists of 4 to 20 steel pipes, which intersect the burner axis at a certain angle. After being ejected, the oxygen nozzle forms a swirling flow with the annular airflow, promoting a strong agitated airflow. The gas cavity and air cavity are welded and fixed together as a single unit, ensuring the consistency of the flow field. The oxygen and air nozzles are rationally arranged, resulting in a uniform flow field. Actual commissioning shows that the oxygen and air flow rates can be adjusted from using only air, mixing air and oxygen at a certain concentration, to using only oxygen, all with excellent performance. This meets the requirements for industrial applications where a single burner can provide air for combustion from a blower, as well as for oxygen-enriched combustion and pure oxygen combustion.

[0009] Furthermore, the gas inlet, air inlet, and oxygen inlet are all equipped with one-way mechanisms. The one-way mechanism includes a support rod, and the surface of the support rod is movably connected to an arc-shaped sealing plate via a pin and a torsion spring.

[0010] The above technical solution, through the setting of support rods, facilitates the fixing of the arc-shaped sealing plate and improves the stability of the arc-shaped sealing plate rotation.

[0011] Furthermore, positioning rings are fixedly connected to the inner walls of the gas inlet, air inlet, and oxygen inlet, and rubber sealing gaskets are fixedly connected to the side of the positioning rings that contacts the arc-shaped sealing plate.

[0012] The above technical solution facilitates the sealing of the arc-shaped sealing plate by using a rubber sealing gasket, while the positioning ring prevents the arc-shaped sealing plate from rotating in the opposite direction, making it convenient for users.

[0013] The above-described solution of this utility model has at least the following beneficial effects:

[0014] 1. This utility model achieves the advantages of accelerating combustion speed, promoting complete combustion, reducing the ignition temperature and burnout temperature of fuel, reducing exhaust volume after combustion, increasing heat utilization rate, significantly improving energy saving effect, and reducing excess air coefficient through the setting of components such as gas inlet and automatic ignition switch, thus saving energy and reducing consumption, and is convenient for users to use.

[0015] 2. This utility model, through the setting of a one-way mechanism, facilitates the discharge of gas in only one direction, thereby effectively improving the overall stability and safety of the device and making it easier for users to use. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the gas chamber structure of this utility model;

[0017] Figure 2 This is a utility model Figure 1 A magnified structural diagram of section A;

[0018] Figure 3 This is a schematic diagram of the oxygen nozzle structure of this utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1. Gas inlet; 2. Gas chamber; 3. Automatic ignition switch; 4. Air inlet; 5. Air chamber; 6. Mounting base plate; 7. Burner nozzle; 8. Gas nozzle; 9. Central air supply; 10. Oxygen nozzle; 11. Oxygen inlet; 12. One-way mechanism; 13. Support rod; 14. Arc-shaped sealing plate; 15. Positioning ring; 16. Rubber sealing gasket. Detailed Implementation

[0021] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0022] like Figures 1 to 3 As shown, this utility model provides a multi-layer pure oxygen burner for a steel ladle tundish baking oven, comprising: a gas inlet 1, a gas chamber 2 connected to the top of the gas inlet 1, an automatic ignition switch 3 provided at the top of the gas chamber 2, an air inlet 4 provided at the top of the gas chamber 2, an air chamber 5 provided on the right side of the top of the gas chamber 2, the air inlet 4 and the air chamber 5 being interconnected, a mounting base plate 6 fixedly connected to the right side of the air chamber 5, a burner nozzle 7 provided on the right side of the mounting base plate 6, a gas nozzle 8 provided on the right side of the gas chamber 2, a central air supply 9 provided on the right side of the gas chamber 2, oxygen nozzles 10 provided at both the top and bottom of the gas chamber 2, and an oxygen inlet 11 connected to the bottom of the gas chamber 2.

[0023] like Figures 1 to 3 As shown, the gas inlet 1, air inlet 4 and oxygen inlet 11 are all equipped with one-way mechanisms 12. The one-way mechanism 12 includes a support rod 13, and the surface of the support rod 13 is movably connected to an arc-shaped sealing plate 14 by a pin and a torsion spring.

[0024] like Figures 1 to 3 As shown, a positioning ring 15 is fixedly connected to the inner wall surface of the gas inlet 1, the air inlet 4, and the oxygen inlet 11. A rubber sealing gasket 16 is fixedly connected to the side of the positioning ring 15 that contacts the arc-shaped sealing plate 14.

[0025] In this embodiment of the invention, the burner mounting plate and the burner nozzle are connected by a flange, allowing for easy disassembly and adjustment, suitable for on-site installation angle adjustment. This reduces the need for standardization of product components, thus reducing the quantity and types of spare parts. The burner integrates an automatic ignition device, enabling both remote and automatic ignition. All media in the multi-stage pure oxygen burner are mixed externally, making it an externally mixed burner and eliminating the risk of backfire. The multi-stage pure oxygen burner offers a wide capacity and adjustment range, with an adjustment ratio of up to 1:20. It exhibits strong adaptability to pressure changes in fuel gas, air, and oxygen. The fuel gas, air, and oxygen in the multi-stage pure oxygen burner can be preheated to higher temperatures. Due to the multi-stage mixing, multiple flame surfaces are formed, resulting in good combustion stability, high heat load, and a uniform temperature field, overcoming the limitations of existing burners in fuel combustion. The combustion process is incomplete, with low efficiency and a tendency to produce black smoke. Due to its multi-layered mixing, it forms multiple flame surfaces, resulting in good combustion stability, high heat load, and a uniform temperature field. This overcomes the serious impact of localized bright flames and high temperatures on the service life of the burner and refractory materials of steel ladles caused by existing burners, significantly reducing production costs. The multi-layered, multi-stage combustion produces a very uniform flame distribution, with extremely low NOx and CO formation, below 10 ppm and 0 ppm respectively. The multi-layered mixing creates multiple flame surfaces, ensuring good combustion stability and excellent adjustability. By adjusting the different jet velocities and flow rates of different fluids, flames of different lengths and shapes can be formed, making it suitable for baking steel ladles and tundishes.

[0026] Pure oxygen combustion has the following advantages: it increases the flame temperature in the combustion zone.

[0027] The flame temperature increases significantly with increasing oxygen content in the air, as shown in the figure below:

[0028]

[0029] Flame temperature increases with increasing oxygen levels in the air; however, the rate of increase in flame temperature gradually decreases as the concentration of pure oxygen in the air gradually increases. Therefore, to effectively utilize pure oxygen in the air, its concentration should not be too high. When organizing fuel according to an excess coefficient a = 1.1-1.5, a pure oxygen concentration of 25-30% is preferable, with the most significant effect observed when the air content is between 21-28%.

[0030] Accelerate combustion speed and promote complete combustion;

[0031] The reason why fuel burns faster in pure oxygen and air is that the increased oxygen content raises the flame temperature. For example, natural gas burns 10.7 times faster in oxygen than in ordinary air. This increased combustion speed leads to rapid and complete combustion of the fuel in the furnace.

[0032] Lower the ignition temperature and burnout temperature of the fuel;

[0033] The ignition temperature is significantly affected by the reaction rate and heat loss. Pure oxygen-air, compared to ordinary air, helps to lower the ignition temperature and increases the heat release per unit volume of the flame. This effect is even more pronounced with low-quality fuels.

[0034] The ignition temperature of fuel is not constant under certain conditions. For example, CO has an ignition temperature of 609°C in air, but only 388°C in pure oxygen. Pure oxygen-assisted combustion utilizes this phenomenon by supplying a small amount of pure oxygen to the burner just as the fuel is atomized (or solid fuel is just vaporized) and ejected from the ignition point. This sudden increase in oxygen levels in that area lowers the fuel ignition temperature, advances ignition, relatively prolongs the combustion time in the furnace, and increases the heat released by the fuel.

[0035] Reduce exhaust volume after combustion

[0036] As shown in the diagram below, if conventional air with an oxygen concentration of 21% is used, and the exhaust volume is calculated based on a theoretical air volume of 1, the exhaust volume tends to decrease as the oxygen content increases. Compared to combustion with air containing 21% oxygen, combustion with pure oxygen containing 27% oxygen results in a 21% reduction in exhaust volume when the excess coefficient a = 1, and the heat loss from the flue gas is also reduced accordingly, thus saving energy.

[0037]

[0038] Increased heat utilization rate results in significant energy savings; the multi-stage pure oxygen burner produces only 1 / 3 the flue gas of existing burners. This means that within the same combustion space (steel ladle tundish), the flue gas produced by the multi-stage pure oxygen burner can remain inside the steel ladle tundish for a longer period, fully exchanging heat with the refractory material, further improving heat utilization rate and reducing fuel consumption. According to relevant data, when the heating temperature is 1300℃, the heat utilization rate using ordinary air is 42%, while using pure oxygen air with an oxygen content of 24% increases the utilization rate to over 50%. The energy-saving effect becomes more significant as the heating temperature increases.

[0039] Reducing the excess air coefficient saves energy and reduces consumption. Complete combustion in the furnace further lowers the excess air coefficient. According to relevant data, the Japan Energy Conservation Center focuses on reducing the excess air coefficient in its research on energy-saving measures for industrial kilns. Through multiple experiments in a heat treatment furnace, they reduced the excess air coefficient from 1.7 to 1.2, a reduction of 29.4%, achieving an average energy saving of 13.3%.

[0040] Due to its compact and simple structure, it can be equipped with flame detection and automatic ignition, and can be used in the combustion systems of various enclosed heating furnaces such as alloy baking furnaces, scrap steel baking furnaces, heating furnaces, and annealing furnaces.

[0041] Table 1. Operating Conditions of Multi-Stage Pure Oxygen Burners

[0042]

[0043] The rated combustion capacity and rated gas and air flow rates in Table 2 are values ​​when both gas and air are at their rated pressures and temperatures are at room temperature. When the operating pressure or preheating temperature of the gas and air differs from the rated pressure and temperature, the burner's combustion capacity and excess air coefficient will change. To ensure the burner always operates at a suitable excess air coefficient, the gas and air pressures should be adjusted to match each other under different operating conditions.

[0044] At a constant pressure, the effect of changes in air and gas temperature on their mass flow rate is expressed by the following formula:

[0045]

[0046] That is, an increase in gas temperature will lead to a decrease in its mass flow rate. When the air or gas is preheated, in order to achieve the rated burner capacity and match the mass flow rate ratio of air and gas, it is necessary to adjust the pressure of the air or gas before the burner. At the preheating temperature t, in order to counteract the effect of temperature increase on the gas mass flow rate, the pressure of the gas before the burner needs to be adjusted according to equation (2):

[0047]

[0048] Table 2. Technical Performance of Multi-Stage Pure Oxygen Burners

[0049]

[0050] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A multi-stage pure oxygen burner for baking intermediate ladles in steel ladles, characterized in that, include: A gas inlet (1) is provided, and a gas chamber (2) is connected to the top of the gas inlet (1). An automatic ignition switch (3) is provided on the top of the gas chamber (2). An air inlet (4) is provided on the top of the gas chamber (2). An air chamber (5) is provided on the right side of the top of the gas chamber (2). The air inlet (4) and the air chamber (5) are connected to each other. An installation base plate (6) is fixedly connected to the right side of the air chamber (5). A burner nozzle (7) is provided on the right side of the installation base plate (6). A gas nozzle (8) is provided on the right side of the gas chamber (2). A central air supply (9) is provided on the right side of the gas chamber (2). Oxygen nozzles (10) are provided at both the top and bottom of the gas chamber (2). An oxygen inlet (11) is connected to the bottom of the gas chamber (2).

2. The multi-layer pure oxygen burner for a steel ladle tundish baking oven according to claim 1, characterized in that, The gas inlet (1), air inlet (4) and oxygen inlet (11) are all equipped with a one-way mechanism (12). The one-way mechanism (12) includes a support rod (13). The surface of the support rod (13) is movably connected to an arc-shaped sealing plate (14) by a pin and a torsion spring.

3. The multi-stage pure oxygen burner for a steel ladle tundish baking oven according to claim 1, characterized in that, A positioning ring (15) is fixedly connected to the inner wall of the gas inlet (1), air inlet (4), and oxygen inlet (11), and a rubber sealing gasket (16) is fixedly connected to the side of the positioning ring (15) that contacts the arc-shaped sealing plate (14).

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