Low-cost oxygen-enriched combustion-supporting device for pellet rotary kiln

Abstract

The utility model discloses a low-cost oxygen-enriched combustion-supporting device for a pellet rotary kiln. The low-cost oxygen-enriched combustion-supporting device comprises an oxygen pipeline, a nitrogen pipeline and a coal gas pipeline. The oxygen pipeline comprises an oxygen pipeline body, an oxygen generator, an oxygen mixer and an air blower, the oxygen generator, the oxygen mixer and the air blower are sequentially connected to the oxygen pipeline body, the oxygen generator is connected to one end of the oxygen pipeline body, and the other end of the oxygen pipeline body is connected with the rotary kiln combustor. The nitrogen pipeline comprises a nitrogen pipeline, a stop check valve and a nitrogen supply device, the stop check valve is connected to the nitrogen pipeline, the nitrogen supply device is connected to one end of the nitrogen pipeline, and the other end of the nitrogen pipeline is connected to the oxygen pipeline and located between the oxygen generator and the oxygen mixer on the oxygen pipeline. And a gas outlet of the gas pipeline is communicated with the rotary kiln combustor. When potential safety hazards exist in the air blower, the nitrogen supply device conveys nitrogen into the rotary kiln combustor through the nitrogen pipeline and the oxygen pipeline in sequence for nitrogen filling protection, and the combustion-supporting hot air blower is prevented from being damaged.

Description

Technical Field

[0001] The present application belongs to the field of pelletizing rotary kiln combustion-supporting technology, and specifically relates to a low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln. Background Art

[0002] The domestic iron and steel metallurgical industry is dominated by long-process technology, and pre-iron processes such as pelletizing are the largest energy consumers in the entire system. In the pelletizing process, the rotary kiln burner mainly uses air for combustion, which has prominent problems such as low combustion efficiency, high energy consumption, and serious nitrogen oxide emissions.

[0003] In the related technology, the high-pressure oxygen pipeline above 0.2MPa is mainly led to the outlet pipeline of the combustion-supporting fan, so as to achieve the goal of oxygen-enriched combustion in the system. At present, large steel enterprises generally adopt deep-cold air separation to produce oxygen. Therefore, the oxygen pressure of 1.0-1.6MPa is generally adjusted to 0.2-0.6MPa, and then the oxygen is enriched after the blower and connected to the combustion-supporting air duct after the blower. This oxygen enrichment method not only wastes the oxygen pressure regulation energy level, but also loses the oxygen purity grade, which is neither energy-saving nor economical. Utility Model Content

[0004] In order to solve the problems of low pellet combustion efficiency, high oxygen-enriched energy consumption and high cost in related technologies.

[0005] The present application provides a low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln, and the low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln comprises:

[0006] An oxygen pipeline, the oxygen pipeline comprises an oxygen pipeline, an oxygen concentrator, an oxygen mixer and a blower, the oxygen concentrator, the oxygen mixer and the blower are sequentially connected to the oxygen pipeline, the oxygen concentrator is connected to one end of the oxygen pipeline, and the other end of the oxygen pipeline is connected to a rotary kiln burner;

[0007] A nitrogen pipeline, the nitrogen pipeline comprising a nitrogen pipeline and a nitrogen supply device, the nitrogen supply device being connected to one end of the nitrogen pipeline, the other end of the nitrogen pipeline being connected to the oxygen pipeline, and being located between the oxygen concentrator and the oxygen mixer on the oxygen pipeline;

[0008] A gas pipeline, wherein a gas outlet of the gas pipeline is connected to the rotary kiln burner.

[0009] In some embodiments, the oxygen pipeline further includes a first stop valve, which is connected to the oxygen pipeline and located between the oxygen concentrator and the oxygen mixer; the nitrogen pipeline is connected between the first stop valve and the oxygen mixer.

[0010] In some embodiments, the oxygen pipeline further includes a flow regulating valve and a flow meter, wherein the flow regulating valve and the flow meter are connected to the oxygen pipeline and are located between the nitrogen pipeline connection position on the oxygen pipeline and the first shut-off valve.

[0011] In some embodiments, the oxygen pipeline further includes a safety valve, which is connected to the oxygen pipeline and located between the flow regulating valve and the flow meter.

[0012] In some embodiments, the oxygen pipeline further comprises a quick shut-off valve, which is connected to the oxygen pipeline and is located between the nitrogen pipeline connection position on the oxygen pipeline and the flow meter.

[0013] In some embodiments, the oxygen pipeline further includes a filter, which is connected to the oxygen pipeline and located between the first shut-off valve and the flow regulating valve.

[0014] In some embodiments, the oxygen pipeline further includes a second shut-off valve, which is connected to the oxygen pipeline and is located between the nitrogen pipeline connection position on the oxygen pipeline and the oxygen mixer.

[0015] In one embodiment, the oxygen pipeline further comprises a flame arrester, and the flame arrester is located between the second shut-off valve and the oxygen mixer.

[0016] In some embodiments, the nitrogen pipeline further includes a third stop valve and a quick-opening valve, wherein the third stop valve and the quick-opening valve are connected to the nitrogen pipeline and are located between the stop check valve and the nitrogen supply device.

[0017] In some embodiments, the nitrogen pipeline further includes a relief valve, which is connected to the nitrogen pipeline and located between the third stop valve and the quick-opening valve.

[0018] In some embodiments, the low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln further comprises:

[0019] A rotary kiln burner, the gas pipeline is communicated with the rotary kiln burner, and the oxygen pipeline is communicated with the rotary kiln burner.

[0020] According to one or more embodiments of the present application, a low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln is provided, and the low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln includes an oxygen pipeline, a nitrogen pipeline and a gas pipeline. The oxygen pipeline includes an oxygen pipeline, an oxygen concentrator, an oxygen mixer and a blower, and the oxygen concentrator, the oxygen mixer and the blower are connected to the oxygen pipeline in sequence, the oxygen concentrator is connected to one end of the oxygen pipeline, and the other end of the oxygen pipeline is connected to the rotary kiln burner. The nitrogen pipeline includes a nitrogen pipeline, a stop check valve and a nitrogen supply device, the stop check valve is connected to the nitrogen pipeline, the nitrogen supply device is connected to one end of the nitrogen pipeline, and the other end of the nitrogen pipeline is connected to the oxygen pipeline and is located between the oxygen concentrator and the oxygen mixer on the oxygen pipeline. The gas outlet of the gas pipeline is connected to the rotary kiln burner. When there is a safety hazard in the blower, the nitrogen supply device transports nitrogen to the rotary kiln burner through the nitrogen pipeline and the oxygen pipeline in sequence for nitrogen flushing protection to prevent damage to the combustion-supporting hot blower. A low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln is installed in the pelletizing production area, which can not only improve the oxygen-enriched combustion-supporting intensity of the system but also reduce the cost of oxygen-enriched combustion-supporting. It is an economical, applicable, safe and energy-saving oxygen-enriched combustion-supporting equipment and technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln in one or more embodiments of the present application.

[0022] Description of reference numerals:

[0023] 1. Oxygen generator; 2. Oxygen pipeline; 3. First stop valve; 4. Filter; 5. Flow regulating valve; 6. Safety valve; 7. Flow meter; 8. Quick shut-off valve; 9. Second stop valve; 10. Flame arrester; 11. Oxygen mixer; 13. Blower; 15. Rotary kiln burner; 16. Nitrogen pipeline; 17. Third stop valve; 18. Release valve; 19. Quick opening valve; 20. Stop check valve; 21. Nitrogen supply device. DETAILED DESCRIPTION

[0024] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0025] As a key area of ​​CO2 emissions, the steel industry should focus on developing low-carbon and energy-saving technologies and achieve transformation in production methods.

[0026] At present, the long process technology in the domestic iron and steel metallurgical industry occupies a dominant position, and the pre-iron process such as pelletizing is the largest energy consumer in the entire iron and steel metallurgical system. In the pelletizing process, the rotary kiln burner usually uses air for combustion, which has problems such as low combustion efficiency, high energy consumption, and serious nitrogen oxide emissions.

[0027] The oxygen pipeline connected to the rotary kiln burner in the pelletizing process includes a combustion-supporting hot blower, and oxygen is transported to the rotary kiln burner through the combustion-supporting hot blower on the oxygen pipeline.

[0028] By analyzing the problems caused by air combustion in the rotary kiln burner, in related technologies, a high-pressure oxygen pipeline of more than 0.2MPa is usually led to the outlet pipeline of the combustion-supporting fan to achieve the goal of oxygen-enriched combustion in the system. In the pelletizing process, cryogenic air separation oxygen is usually used to balance the maximum pressure level and maximum oxygen purity of cryogenic air separation oxygen according to the requirements of oxygen pressure and oxygen purity in steelmaking and ironmaking processes. The purity of oxygen obtained by cryogenic air separation oxygen production is usually 99.6%, and the pressure is 1.0MPa~1.6MPa. Since the combustion in the rotary kiln burner does not require high oxygen pressure and oxygen purity, it is usually necessary to adjust the oxygen pressure of 1.0MPa~1.6MPa to 0.2MPa~0.6MPa, and then transport it to the combustion-supporting hot blower. After the combustion-supporting hot blower is used, oxygen is enriched and then the oxygen is transported to the rotary kiln burner for combustion. The use of high-purity and high-pressure oxygen leads to a waste of oxygen pressure adjustment energy level and a loss of oxygen purity grade, which is neither energy-saving nor economical.

[0029] In order to solve the above technical problems, the present application provides a low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln, specifically a low-cost oxygen-enriched combustion-supporting device for the steel industry that uses vacuum pressure swing adsorption oxygen production technology to supply oxygen to a pelletizing rotary kiln.

[0030] See also Figure 1 The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln at least includes an oxygen pipeline, a nitrogen pipeline and a gas pipeline.

[0031] The oxygen pipeline includes an oxygen pipeline 2, an oxygen generator 1, an oxygen mixer 11 and a blower 13. The oxygen generator 1, the oxygen mixer 11 and the blower 13 are connected to the oxygen pipeline 2 in sequence. The oxygen mixer 11 is provided with an interface of the oxygen pipeline 2 and is connected to the oxygen pipeline 2 by a flange connection. The oxygen mixer 11 is integrally welded to the inlet pipeline of the blower 13. The outlet pipeline of the blower 13 is connected to the combustion-supporting air inlet of the rotary kiln burner 15. The oxygen generator 1 is connected to one end of the oxygen pipeline 2 by a flange connection, and the other end of the oxygen pipeline 2 is connected to the rotary kiln burner 15.

[0032] It should be noted that the material of the oxygen pipe 2 can be 06Cr19Ni10, or other materials that meet the requirements of the specifications. The specific material can be set according to actual needs and is not limited in this application.

[0033] The oxygen mixer 11 is provided with a low-pressure oxygen inlet and an air inlet, and the oxygen pipeline 2 is connected to the low-pressure oxygen inlet, and the oxygen concentrator 1 is connected to the oxygen mixer 11 through the oxygen pipeline 2. The oxygen concentrator 1 uses a vacuum pressure swing adsorption method to produce oxygen, and can provide oxygen with a purity of 80% and a pressure of 15-45 kPa. The oxygen concentrator 1 provides oxygen to the oxygen mixer 11, and air enters the oxygen mixer 11 through the air inlet. A plurality of nozzles with different angles are arranged in the oxygen mixer 11, so that oxygen is output from different nozzles, and due to the different angles of the nozzles, oxygen and air can collide and mix evenly to reach a mixed state, so that the oxygen mixer 11 can output homogeneously mixed oxygen to the blower 13. The oxygen obtained by mixing in the oxygen mixer 11 is transported from the outlet pipeline of the blower 13 to the rotary kiln burner 15 under the pressure boosting action of the blower 13, so as to realize low-pressure oxygen enrichment of the rotary kiln burner 15. In order to make the oxygen pressure and oxygen purity suitable for the oxygen-enriched combustion-supporting working conditions of the pelletizing rotary kiln, the low-pressure oxygen delivered by the vacuum pressure swing adsorption oxygen generator is connected to the rotary kiln burner 15 by the oxygen-enriched method in front of the blower 13, thereby improving the oxygen enrichment rate of the rotary kiln burner 15 and ensuring the combustion efficiency of the rotary kiln burner 15.

[0034] Since the vacuum pressure swing adsorption oxygen generator adopts vacuum pressure swing adsorption method to produce oxygen, it can provide oxygen with a purity of 80% and a pressure of 15-45kPa. Compared with the oxygen obtained by cryogenic air separation oxygen production, it can meet the needs of oxygen-enriched combustion in the pelletizing rotary kiln, effectively reduce the cost of oxygen-enriched combustion, improve combustion efficiency and save energy consumption.

[0035] The low-cost oxygen-enriched combustion-supporting device for the pelletizing rotary kiln uses a vacuum pressure swing adsorption oxygen generator as the oxygen supply source and adopts the oxygen enrichment method before the blower 13 to reduce energy consumption and loss of oxygen purity grade, thereby reducing the cost and energy consumption of oxygen-enriched combustion in the pelletizing rotary kiln.

[0036] The blower 13 can be a Roots blower or a centrifugal blower, etc. The inlet pipe and the outlet pipe of the blower 13 can be made of 06Cr19Ni10. The specific material can also be set according to actual needs, and this application does not limit it.

[0037] Since the purity is 80% and it is evenly mixed with the air in the oxygen mixer 11, the purity of the oxygen output by the oxygen mixer 11 can be adjusted to about 23.5%, which meets the demand for oxygen-enriched combustion in the rotary kiln burner 15, ensures the oxygen purity required for combustion in the rotary kiln burner 15, and reduces the loss of oxygen purity grade. Compared with the rotary kiln burner 15 in the related art, which usually uses air for combustion, the vacuum pressure swing adsorption oxygen generator provides sufficient oxygen. The increase in oxygen concentration can increase the intensity of oxygen-enriched combustion in the rotary kiln burner 15, which can effectively improve the combustion efficiency and product quality of the rotary kiln burner 15; at the same time, since the rotary kiln burner 15 adopts a low-pressure oxygen-enriched combustion method, it can reduce the energy consumption of the rotary kiln burner 15 and the cost of oxygen-enriched combustion, and improve the economic benefits and energy saving of the system.

[0038] The output oxygen pressure of the vacuum pressure swing adsorption oxygen generator is 15kPa-45kPa. The output oxygen is transported to the oxygen mixer 11 and evenly mixed with the air, and is pressurized to the pressure required by the rotary kiln burner 15 by the blower 13, so that the oxygen pressure level and oxygen purity are suitable for the oxygen demand of the rotary kiln burner 15 for oxygen-enriched combustion, and low-cost oxygen-enriched combustion is achieved for the rotary kiln burner 15. Compared with the input of high-pressure and high-purity oxygen, this can prevent the waste of oxygen pressure regulation energy level and achieve low-cost oxygen-enriched combustion.

[0039] At the same time, compared with the related art in which air is used to assist combustion in the rotary kiln burner 15, combustion is achieved in the rotary kiln burner 15 in an oxygen-rich state. Since the oxygen transported in the rotary kiln burner 15 includes air uniformly mixed with high-purity oxygen, the amount of air added in the rotary kiln burner 15 is reduced to a certain extent, which also reduces the nitrogen content in the rotary kiln burner 15, preventing nitrogen from taking away more effective heat, and improving the combustion efficiency of the rotary kiln burner 15. At the same time, it also reduces the generation of nitrogen oxides to a certain extent, reducing pollution. Since the combustion efficiency in the rotary kiln burner 15 is improved, the pellet yield and product quality can be improved.

[0040] See also Figure 1 The nitrogen pipeline includes a nitrogen pipeline 16, a stop check valve 20 and a nitrogen supply device 21. The nitrogen pipeline 16 is arranged in parallel with the oxygen pipeline 2. The stop check valve 20 is connected to the nitrogen pipeline 16. The nitrogen supply device 21 is connected to one end of the nitrogen pipeline 16. The other end of the nitrogen pipeline 16 is connected to the oxygen pipeline 2 and is located between the vacuum pressure swing adsorption oxygen generator and the oxygen mixer 11 on the oxygen pipeline 2.

[0041] When the oxygen enrichment rate in the rotary kiln burner 15 exceeds the set value or there is a safety hazard in the blower 13, the nitrogen supply device 21 delivers nitrogen to the rotary kiln burner 15 through the nitrogen pipeline 16 and the oxygen pipeline 2 in sequence for nitrogen flushing protection. It should be noted that the set value of the oxygen enrichment rate in the rotary kiln burner 15 can be determined according to the combustion process requirements in the rotary kiln burner 15, and this application does not limit it.

[0042] It should be noted that the nitrogen supply device 21 is installed in the nitrogen pipeline 16, and the pressure level is usually 0.6MPa to 0.8MPa.

[0043] Understandably, the oxygen pipeline also includes a first stop valve 3 and a second stop valve 9, the first stop valve 3 is connected to the oxygen pipeline 2 by a flange connection, and is located between the vacuum pressure swing adsorption oxygen generator and the oxygen mixer 11; the nitrogen pipeline 16 is connected between the first stop valve 3 and the oxygen mixer 11. The second stop valve 9 is connected to the oxygen pipeline 2 by a flange connection, and is located between the connection position of the nitrogen pipeline 16 on the oxygen pipeline 2 and the oxygen mixer 11. The first stop valve 3 and the second stop valve 9 can be oxygen stop valves with bypass form. When it is necessary to overhaul the low-cost oxygen-enriched combustion-supporting device for the pelletizing rotary kiln, the first stop valve 3 and the second stop valve 9 can be closed to prevent the oxygen in the oxygen pipeline from affecting the overhaul of the low-cost oxygen-enriched combustion-supporting device for the pelletizing rotary kiln, which ensures the effectiveness of the overhaul and improves the convenience and efficiency of the overhaul.

[0044] In order to more accurately control the flow rate of oxygen in the oxygen pipeline 2 to meet the demand for oxygen in the oxygen mixer 11, the oxygen pipeline also includes a flow regulating valve 5 and a flow meter 7, which are respectively connected to the oxygen pipeline 2 by flange connection, and are located between the first stop valve 3 and the connection position of the nitrogen pipeline 16 on the oxygen pipeline 2. The flow regulating valve 5 can dynamically adjust the opening of the flow regulating valve 5 according to the indication of the flow meter 7 to adjust the oxygen flow in the oxygen pipeline 2. The flow meter 7 can be an orifice flow meter or a mass flow meter, which can realize temperature and pressure correction and instantaneous and cumulative measurement. The flow meter 7 can be connected to the controller, and the flow rate and pressure of oxygen in the oxygen pipeline can be displayed through a display connected to the controller. The flow regulating valve 5 can be adjusted according to the flow rate and pressure displayed by the display, combined with the flow rate of oxygen required in the oxygen mixer 11; at the same time, the use of the display can visualize the flow rate and pressure of oxygen in the oxygen pipeline 2, and improve the accuracy and convenience of the adjustment of the flow meter 7.

[0045] In order to improve the safety performance of the system, the oxygen pipeline also includes a safety valve 6 and a quick shut-off valve 8. The safety valve 6 is connected to the oxygen pipeline 2 by welding and is located between the flow regulating valve 5 and the flow meter 7. The quick shut-off valve 8 is connected to the oxygen pipeline 2 by flange connection and is located between the connection position of the nitrogen pipeline 16 on the oxygen pipeline 2 and the first shut-off valve 3.

[0046] The set pressure of the safety valve 6 is 0.1MPa. When the oxygen pipeline is over-pressured, the valve of the safety valve 6 automatically opens and releases safely. The outlet pipe of the safety valve 6 is led to a safe place, which is usually more than 4m above the operating surface to ensure the safety of the release of the safety valve 6. The quick cut-off valve 8 can be an air-open type, and the control voltage of the solenoid valve and the proximity switch (it should be noted that the proximity switch is a single coil and must not be powered under normal working conditions) is AC220V, and it can be connected to the controller and display the opening and closing state of the quick cut-off valve 8 on the display, so that the opening and closing state of the quick cut-off valve 8 can be visualized, improving the convenience and accuracy of the operation and control of the quick cut-off valve 8. At the same time, a chain protection program is provided between the quick cut-off valve 8 and the blower 13. When there is a safety hazard in the blower 13, the quick cut-off valve 8 quickly cuts off the oxygen supply in the oxygen pipeline 2 and performs nitrogen flushing protection to ensure the safety of the low-cost oxygen-enriched combustion-supporting device used for the pelletizing rotary kiln.

[0047] To ensure the safety of each component connected to the oxygen pipeline 2, please refer to Figure 1 The oxygen pipeline further includes a filter 4, which is connected to the low-pressure oxygen pipeline 2 by a flange connection and is located between the first stop valve 3 and the quick shut-off valve 8. The maximum working pressure of the filter 4 is 55 kPa, the mesh size is 0.16 mm, the filtration accuracy is at least 80 meshes, the shell of the filter 4 is made of stainless steel, the internal parts of the filter 4 are made of copper alloy or copper, and the filter screen is made of nickel-copper alloy, which can prevent impurities in the oxygen pipeline 2 from entering the subsequent system to damage various components connected to the oxygen pipeline 2, thereby improving the service life of various components.

[0048] In order to prevent sparks of the rotary kiln burner 15 system from entering the oxygen pipeline 2, the oxygen pipeline also includes a flame arrester 10, which is connected to the oxygen pipeline 2 by welding and is located between the second stop valve 9 and the oxygen mixer 11, and the outlet of the flame arrester 10 is connected to the low-pressure oxygen inlet in the oxygen mixer 11. The material of the flame arrester section of the flame arrester 10 is copper, and the material of the short pipes at both ends of the flame arrester section of the flame arrester 10 is 06Cr19Ni10.

[0049] In some embodiments, the type of the flame arrester 10 can also be set according to actual needs, and this application does not limit it.

[0050] The nitrogen pipeline also includes a third stop valve 17 and a quick-opening valve 19, which are connected to the nitrogen pipeline 16 and are located between the stop check valve 20 and the nitrogen supply device 21. The third stop valve 17 is the main valve of the security system, which is normally open. When the device is overhauled, it should be closed first. The quick-opening valve 19 is an air-opening type. When it is normally open, the quick-opening valve 19 must not be energized. In the accident state, the quick-opening valve 19 is closed, and the accident closing time is ≤3s. It is equipped with an electromagnetic valve AC220V or DC24V (single coil), a proximity switch (input display), a venting valve and a triple piece (pressure reducing filter and oil mist, etc.). The valve housing, opening and closing parts and valve stem of the quick-opening valve 19 are austenitic stainless steel or copper alloy. The stop check valve 20 has a stop function and a check function, which can effectively prevent oxygen from entering the nitrogen pipeline 16 and prevent cross-gas. The material of the quick-opening valve 19 is stainless steel.

[0051] It is understandable that the nitrogen pipeline also includes a relief valve 18, which is connected to the nitrogen pipeline 16 and is located between the third stop valve 17 and the quick-opening valve 19. The relief valve 18 is a stop valve and is a safety facility of the security system.

[0052] It can be understood that the low-cost oxygen-enriched combustion-supporting device for the pelletizing rotary kiln includes an oxygen pipeline and a nitrogen pipeline. The oxygen pipeline includes an oxygen pipeline 2 and a vacuum pressure swing adsorption oxygen generator, a first stop valve 3, a filter 4, a flow regulating valve 5, a safety valve 6, a flow meter 7, a quick shut-off valve 8, a second stop valve 9, a flame arrester 10, an oxygen mixer 11 and a blower 13 connected to the oxygen pipeline 2 in sequence. One end of the oxygen pipeline 2 is connected to the vacuum pressure swing adsorption oxygen generator, and the other end is connected to the rotary kiln burner 15.

[0053] The nitrogen pipeline includes a nitrogen pipeline 16 and a nitrogen supply device 21, a third stop valve 17, a relief valve 18, a quick-opening valve 19, and a stop check valve 20 which are sequentially connected to the nitrogen pipeline 16. One end of the nitrogen pipeline 16 is connected to the nitrogen supply device 21, and the other end is connected between the quick-cut valve 8 and the second stop valve 9 on the oxygen pipeline 2.

[0054] The vacuum pressure swing adsorption oxygen generator provides low-pressure oxygen, and the vacuum pressure swing adsorption oxygen generator transports the oxygen to the oxygen mixer 11 for oxygen enrichment and mixing, and transports the oxygen-enriched gas to the rotary kiln burner 15, thereby reducing the waste of oxygen pressure regulation energy level and the loss of oxygen purity grade by lowering the oxygen pressure and oxygen purity.

[0055] The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln also includes a rotary kiln burner 15 and a gas pipeline for conveying coal gas. The gas pipeline is connected to the rotary kiln burner 15, and the oxygen pipeline is connected to the rotary kiln burner 15.

[0056] The gas pipeline for conveying coal gas is arranged in parallel with the oxygen pipeline, and the gas outlet of the gas pipeline is connected with the gas inlet of the rotary kiln burner 15. The coal gas is conveyed to the rotary kiln burner 15 through the gas pipeline, and is burned in the rotary kiln burner 15 with the oxygen input through the blower 13. In the oxygen-rich state, the ignition temperature of the coal gas can be ensured, the calorific value requirement of the coal gas can be met, and the coal gas can be burned in the rotary kiln burner 15. The low calorific value coal gas is input into the rotary kiln burner 15 through the gas pipeline, and a coal gas combustion system is constructed in the rotary kiln burner 15 to achieve stable ignition and combustion.

[0057] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0058] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0060] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0061] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln, characterized in that: The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln comprises: An oxygen pipeline, the oxygen pipeline comprises an oxygen pipeline, an oxygen concentrator, an oxygen mixer and a blower, the oxygen concentrator, the oxygen mixer and the blower are sequentially connected to the oxygen pipeline, the oxygen concentrator is connected to one end of the oxygen pipeline, and the other end of the oxygen pipeline is connected to a rotary kiln burner; A nitrogen pipeline, the nitrogen pipeline comprising a nitrogen pipeline, a stop check valve and a nitrogen supply device, the stop check valve is connected to the nitrogen pipeline, the nitrogen supply device is connected to one end of the nitrogen pipeline, the other end of the nitrogen pipeline is connected to the oxygen pipeline, and is located between the oxygen concentrator and the oxygen mixer on the oxygen pipeline; A gas pipeline, wherein a gas outlet of the gas pipeline is connected to the rotary kiln burner.

2. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 1, characterized in that: The oxygen pipeline also includes a first stop valve, which is connected to the oxygen pipeline and located between the oxygen concentrator and the oxygen mixer; the nitrogen pipeline is connected between the first stop valve and the oxygen mixer.

3. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 2, characterized in that: The oxygen pipeline further comprises a flow regulating valve and a flow meter, wherein the flow regulating valve and the flow meter are connected to the oxygen pipeline and are located between the nitrogen pipeline connection position on the oxygen pipeline and the first stop valve.

4. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 3, characterized in that: The oxygen pipeline further comprises a safety valve, which is connected to the oxygen pipeline and is located between the flow regulating valve and the flow meter.

5. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 3, characterized in that: The oxygen pipeline further comprises a quick cut-off valve, which is connected to the oxygen pipeline and is located between the nitrogen pipeline connection position on the oxygen pipeline and the flow meter.

6. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 3, characterized in that: The oxygen pipeline further includes a filter, which is connected to the oxygen pipeline and is located between the first stop valve and the flow regulating valve.

7. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 1, characterized in that: The oxygen pipeline further comprises a second stop valve, which is connected to the oxygen pipeline and is located between the nitrogen pipeline connection position on the oxygen pipeline and the oxygen mixer.

8. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 7, characterized in that: The oxygen pipeline further comprises a flame arrester, which is connected to the oxygen pipeline and is located between the second stop valve and the oxygen mixer.

9. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 1, characterized in that: The nitrogen pipeline further includes a third stop valve and a quick-opening valve, wherein the third stop valve and the quick-opening valve are connected to the nitrogen pipeline and are located between the stop check valve and the nitrogen supply device.

10. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 9, characterized in that: The nitrogen pipeline further comprises a relief valve, which is connected to the nitrogen pipeline and is located between the third stop valve and the quick-opening valve.

11. The low-cost oxygen-enriched combustion-supporting device for a pelletizing rotary kiln according to claim 1, characterized in that: Also includes: A rotary kiln burner, the gas pipeline is communicated with the rotary kiln burner, and the oxygen pipeline is communicated with the rotary kiln burner.

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