Combustion device and method based on steam secondary air

Abstract

The present invention provides a combustion device and method based on steam secondary air, the device comprising a steam generating device, a steam guide device, a secondary air double-layer nozzle and a rotary kiln, wherein the steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle, and the secondary air double-layer nozzle sprays the steam and the secondary air into the rotary kiln together. According to the combustion device and method based on steam secondary air provided by the present invention, the steam and the secondary air are sprayed into the rotary kiln together through the secondary air double-layer nozzle, which increases the content of hydroxyl in the rotary kiln and increases the combustion rate of carbon monoxide in the mixed flue gas of the secondary combustion chamber, thereby reducing the emission of carbon monoxide and improving the combustion efficiency, while avoiding the consumption of auxiliary fuel and saving resources.

Description

Technical Field

[0001] The invention relates to the field of hazardous waste treatment, and in particular to a device and method based on steam secondary air combustion. Background Art

[0002] With the rapid development of my country's economy, the amount of hazardous waste has increased dramatically. In view of its potential environmental risks and threats to human health, hazardous waste has become one of the major environmental problems facing my country. Incineration can effectively destroy toxic and harmful organic wastes in wastes, reduce the volume and quality of wastes, and facilitate the final safe disposal of wastes. It is the fastest and most effective technology to achieve the reduction and harmlessness of hazardous wastes.

[0003] The use of rotary kilns to incinerate hazardous wastes is currently the mainstream technology for hazardous waste incineration. In conventional hazardous waste incineration, the primary air enters the furnace through the rotary kiln head to dry, burn, and burn out the fuel, while the secondary air is only used as a secondary combustion chamber to supplement the combustion of a small amount of unburned materials. However, since most of the hazardous waste materials currently being incinerated have a high volatile content, they will burn rapidly after the primary air is introduced into the kiln head, resulting in deflagration and a large amount of carbon monoxide. When these carbon monoxides pass through the secondary combustion chamber, they cannot form secondary combustion due to the large negative pressure in the secondary combustion chamber, uneven combustion, high pressure loss of the secondary air ring arrangement, and weak penetration. The carbon monoxide fails to burn fully, resulting in excessive carbon monoxide emissions. In addition, since the temperature of the secondary air is much lower than the combustion temperature in the furnace, this part of the secondary air will cause the temperature of the secondary combustion chamber to drop. Therefore, the secondary combustion chamber needs to consume a large amount of auxiliary fuel to raise the temperature to above 1100°C to destroy harmful components such as dioxins in the flue gas, resulting in a waste of resources.

[0004] Therefore, it is necessary to propose a new device and method for incinerating hazardous waste to solve the above problems. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] The present invention provides a combustion device based on steam secondary air, which comprises: a steam generating device, a steam guide device, a secondary air double-layer nozzle and a rotary kiln, wherein the steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle, and the secondary air double-layer nozzle sprays the steam and the secondary air into the rotary kiln together.

[0007] Furthermore, the secondary air double-layer nozzle includes an inner layer and an outer layer, and a support structure is formed between the inner layer and the outer layer.

[0008] Furthermore, the inner layer of the secondary air double-layer nozzle is provided with a steam nozzle configured to spray the steam.

[0009] Furthermore, the outer layer of the secondary air double-layer nozzle is provided with a secondary air nozzle configured to spray the secondary air.

[0010] Furthermore, the steam diversion equipment includes a gas cylinder, a steam distribution pipeline and a steam hose.

[0011] Furthermore, the steam diversion equipment is provided with a flow meter, a pressure regulating valve and a pressure gauge.

[0012] Furthermore, the flow rate of the steam is in the range of 15 m / s to 30 m / s.

[0013] Furthermore, the amount of steam sprayed into the rotary kiln is 5% to 10% of the amount of secondary air.

[0014] Furthermore, it also includes a secondary air distribution pipe that guides the secondary air to the secondary air double-layer nozzle, and the secondary air distribution pipe is arranged adjacent to the steam distribution pipe.

[0015] Furthermore, the steam generating equipment includes a waste heat boiler.

[0016] The present invention also provides a combustion method based on steam secondary air, comprising the following steps:

[0017] The steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle;

[0018] The steam and the secondary air are sprayed into the rotary kiln together through the secondary air double-layer nozzle.

[0019] According to the steam secondary air based combustion device and method provided by the present invention, steam and secondary air are sprayed into the rotary kiln together through the secondary air double-layer nozzle, which increases the hydroxyl content in the rotary kiln and improves the combustion rate of carbon monoxide in the mixed flue gas in the secondary combustion chamber, thereby reducing carbon monoxide emissions and improving combustion efficiency, while avoiding the consumption of auxiliary fuel and saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following drawings of the present invention are used as part of the present invention for understanding the present invention. The drawings show embodiments of the present invention and their descriptions, and are used to explain the device and principle of the present invention. In the drawings,

[0021] Figure 1 A first schematic diagram of a combustion device based on steam secondary air according to an embodiment of the present invention is shown;

[0022] Figure 2 A second schematic diagram of a combustion device based on steam secondary air according to an embodiment of the present invention is shown;

[0023] Figure 3 A flow chart of a combustion method based on steam secondary air according to an embodiment of the present invention is shown.

[0024] Figure ID

[0025] 1. Gas cylinder 2. Steam distribution pipeline

[0026] 3. Secondary air distribution pipeline 4. Flow meter

[0027] 5. Pressure regulating valve 6. Valve

[0028] 7. Pressure gauge 8. Steam hose

[0029] 9. Secondary air double layer nozzle 10. Steam nozzle

[0030] 11. Secondary air nozzle 12. Support structure

[0031] 13. Rotary kiln DETAILED DESCRIPTION

[0032] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0033] In order to fully understand the present invention, detailed steps will be presented in the following description to illustrate the combustion device and method based on steam secondary air proposed by the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0034] It should be understood that when the terms "include" and / or "comprises" are used in this specification, they indicate the existence of the stated features, integers, steps, operations, elements and / or components, but do not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0035] The present invention provides a combustion device based on steam secondary air, such as Figure 1 and Figure 2As shown, it includes a steam generating device, a steam guiding device, a secondary air double-layer nozzle and a rotary kiln, wherein the steam guiding device guides the steam generated by the steam generating device to the secondary air double-layer nozzle, and the secondary air double-layer nozzle sprays the steam and the secondary air into the rotary kiln together.

[0036] Illustratively, in a hazardous waste incineration process, a rotary kiln is an important component configured to incinerate hazardous waste to generate pyrolysis gas.

[0037] In one embodiment, hazardous waste enters a rotary kiln. A primary air inlet is provided at the kiln head of the rotary kiln. Primary air (combustion-supporting air) is introduced from the primary air inlet to dry and burn the hazardous waste in the rotary kiln to generate pyrolysis gas.

[0038] Furthermore, since the hazardous waste raw materials have a high volatile content, they burn rapidly after the primary air is introduced from the primary air inlet, resulting in deflagration and producing a large amount of carbon monoxide.

[0039] For example, in the process of hazardous waste incineration, the secondary combustion chamber is an important component, which is configured to burn the pyrolysis gas generated by the rotary kiln to produce high-temperature flue gas. As an example, the pyrolysis gas generated by the rotary kiln is discharged from the kiln tail of the rotary kiln and enters the secondary combustion chamber to be fully burned as fuel to produce high-temperature flue gas.

[0040] Exemplarily, the steam generating equipment includes but is not limited to a waste heat boiler. In the process of hazardous waste incineration, the waste heat boiler is an important component, which is configured to recover the waste heat of the high-temperature flue gas generated by the secondary combustion chamber. The waste heat of the high-temperature flue gas can be used to heat feed water to generate steam, which in turn drives the generator to generate electricity through a steam turbine.

[0041] Exemplarily, the steam diversion device comprises a gas distribution cylinder 1. In one embodiment, the gas distribution cylinder 1 is a supporting device of a waste heat boiler, and is used to distribute the steam generated by the waste heat boiler to various pipelines.

[0042] Exemplarily, a steam distribution pipe 2 is provided between the gas sub-cylinder 1 and the secondary air double-layer nozzle 9. In one embodiment, the gas sub-cylinder 1 guides the steam generated by the waste heat boiler, the steam exhausted after the steam turbine is utilized, or the steam generated in any process of the incineration of hazardous waste into the steam distribution pipe 2.

[0043] Further, if Figure 1 As shown, the steam distribution pipeline 2 is provided with a flow meter 4 and a pressure regulating valve 5. The flow meter 4 is used to adjust the steam flow rate. As an example, the flow rate of the steam is in the range of 15m / s to 30m / s, and the amount of steam injected into the rotary kiln is 5% to 10% of the secondary air volume. The pressure regulating valve is used to ensure the stability of the steam pressure injected into the rotary kiln.

[0044] like Figure 1 As shown, the steam drainage device further comprises a secondary air distribution pipeline 3, and the secondary air distribution pipeline 3 is arranged adjacent to the steam distribution pipeline 2. Further, a valve 6 is arranged on the secondary air distribution pipeline 3.

[0045] For example, Figure 2 As shown, a pressure gauge 7 and a steam hose 8 are also provided between the steam distribution pipe 2 and the secondary air double-layer nozzle 9. The pressure gauge 7 is a display pressure gauge, which is used to monitor the pressure of the steam sprayed into the rotary kiln 13 in real time. The steam hose 8 is used to connect the steam to the steam nozzle 10 located in the inner layer of the secondary air double-layer nozzle 9.

[0046] For example, Figure 2 As shown, the secondary air double-layer nozzle 9 includes an inner layer and an outer layer, and is configured to spray the steam and the secondary air into the rotary kiln 13. In one embodiment, the inner layer of the secondary air double-layer nozzle 9 is provided with a steam nozzle 10, which is configured to spray the steam; the outer layer of the secondary air double-layer nozzle 9 is provided with a secondary air nozzle 11, which is configured to spray the secondary air.

[0047] Furthermore, a support structure 12 is formed between the inner layer and the outer layer of the secondary air double-layer nozzle 9. In one embodiment, since the steam nozzle 10 is arranged in the inner layer of the secondary air double-layer nozzle 9 and the steam has a certain pressure, the steam nozzle 10 needs to be fixed in the secondary air nozzle 11 located in the outer layer of the secondary air double-layer nozzle 9 through the support structure 12 on the inner side of the rotary kiln.

[0048] In one embodiment, a secondary air inlet is provided at the kiln tail of the rotary kiln 13, and the kiln tail of the rotary kiln is connected to the secondary combustion chamber. A secondary air double-layer nozzle 9 is provided at the secondary air inlet, which sprays steam and secondary air into the rotary kiln 13 together, and then enters the secondary combustion chamber for secondary combustion. Since a large amount of hydroxyl groups are formed at high temperature after steam is sprayed in, the combustion rate of carbon monoxide is greatly improved in the oxygen-rich environment formed by the mixed secondary air, thereby forming a strong secondary combustion in the middle of the secondary combustion chamber, improving the combustion efficiency, burning out carbon monoxide, and reducing carbon monoxide emissions. At the same time, the introduction of steam is conducive to maintaining the furnace temperature of the secondary combustion chamber, ensuring that its outlet temperature is above 1100°C without consuming a large amount of auxiliary fuel, thereby avoiding waste of resources.

[0049] The present invention also provides a combustion method based on steam secondary air, comprising the following steps:

[0050] The steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle;

[0051] The steam and the secondary air are sprayed into the rotary kiln together through the secondary air double-layer nozzle.

[0052] First, refer to Figure 1 and Figure 3 As shown, step S101 is performed: the steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle.

[0053] In one embodiment, hazardous waste enters a rotary kiln, and a primary air inlet is provided at the kiln head of the rotary kiln. Primary air (combustion-supporting air) is introduced from the primary air inlet to dry and burn the hazardous waste in the rotary kiln to generate pyrolysis gas; the pyrolysis gas enters the secondary combustion chamber and burns to generate high-temperature flue gas; the waste heat of the high-temperature flue gas can be used in the waste heat boiler to heat feed water to generate steam, which in turn drives the generator to generate electricity through the steam turbine.

[0054] Exemplarily, the steam generating equipment includes but is not limited to a waste heat boiler; the steam diversion equipment includes a steam cylinder, a steam distribution pipeline and a steam hose.

[0055] In one embodiment, the gas cylinder 1 guides the steam generated by the waste heat boiler, the steam exhausted after being utilized by the steam turbine, or the steam generated in any process of incineration of hazardous wastes to the steam distribution pipeline 2 .

[0056] Next, refer to Figure 2 and Figure 3 As shown, step S102 is performed: the steam and the secondary air are sprayed into the rotary kiln 13 together through the secondary air double-layer nozzle.

[0057] In one embodiment, the secondary air passing through the secondary air distribution pipe 3 is sprayed into the rotary kiln 13 via the secondary air nozzles 11 located at the outer layer of the secondary air double-layer nozzles 9 .

[0058] In one embodiment, the steam passing through the steam distribution pipe 2 is guided by the steam hose 8 to the steam nozzle 10 located at the inner layer of the secondary air double-layer nozzle 9 and sprayed into the rotary kiln 13 .

[0059] Furthermore, the steam also passes through a flow meter 4 for adjusting the steam flow rate, so that the flow rate of the steam is in the range of 15 m / s to 30 m / s, and the amount of steam sprayed into the rotary kiln is 5% to 10% of the secondary air volume; the steam also passes through a pressure regulating valve 5 for ensuring the stability of the steam pressure sprayed into the rotary kiln; the steam also passes through a pressure gauge 7 for real-time monitoring of the pressure of the steam sprayed into the rotary kiln 13.

[0060] In one embodiment, since the hazardous waste raw materials have a high volatile content, they burn rapidly after the primary air is introduced from the primary air inlet, resulting in deflagration and the generation of a large amount of carbon monoxide. Steam and secondary air are sprayed into the rotary kiln 13 together, and then enter the secondary combustion chamber for secondary combustion. Since a large amount of hydroxyl groups are formed at high temperature after the steam is sprayed in, the combustion rate of carbon monoxide is greatly increased in the oxygen-rich environment formed by the mixed secondary air, thereby forming a strong secondary combustion in the middle of the secondary combustion chamber, improving the combustion efficiency, burning out carbon monoxide, and reducing carbon monoxide emissions. At the same time, the introduction of steam is conducive to maintaining the furnace temperature of the secondary combustion chamber, ensuring that its outlet temperature is above 1100°C without the need for a large amount of auxiliary fuel consumption, thereby avoiding waste of resources.

[0061] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A combustion device based on steam secondary air, characterized in that: The invention comprises a steam generating device, a steam guiding device, a secondary air double-layer nozzle and a rotary kiln, wherein the secondary air double-layer nozzle comprises an inner layer and an outer layer, and a supporting structure is formed between the inner layer and the outer layer; the steam generating device comprises a waste heat boiler; wherein the steam guiding device guides the steam generated by the steam generating device to the secondary air double-layer nozzle, and the secondary air double-layer nozzle sprays the steam and the secondary air into the rotary kiln together; the inner layer of the secondary air double-layer nozzle is provided with a steam nozzle configured to spray the steam; the outer layer of the secondary air double-layer nozzle is provided with a secondary air nozzle configured to spray the secondary air; The steam drainage device includes a gas distribution cylinder, a steam distribution pipeline and a steam hose; wherein the amount of steam sprayed into the rotary kiln is 5% to 10% of the secondary air volume; It also includes a secondary air distribution pipeline for guiding the secondary air to the secondary air double-layer nozzle, and the secondary air distribution pipeline is arranged adjacent to the steam distribution pipeline.

2. The device according to claim 1, characterized in that The steam diversion equipment is provided with a flow meter, a pressure regulating valve and a pressure gauge.

3. The device according to claim 1, characterized in that The flow rate of the steam is in the range of 15 m / s to 30 m / s.

4. A combustion method based on steam secondary air, characterized in that: The method is carried out according to any one of claims 1 to 3, wherein the combustion device based on steam secondary air is used for combustion, and the method comprises the following steps: The steam guide device guides the steam generated by the steam generating device to the secondary air double-layer nozzle; The steam and the secondary air are sprayed into the rotary kiln together through the secondary air double-layer nozzle.

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