Cement kiln waste heat utilization and combustion control self-denitrification furnace
By designing a combustion system including a self-nitriding furnace body, a decomposition furnace, a cyclone cylinder, etc. in the cement kiln, and using coal powder to gasify and burn it at high temperature, the problem of unused heat of high-temperature gases and inability to remove NOx in the cement kiln is solved, efficient energy utilization and effective removal of NOx, and reducing environmental pollution and dependence on ammonia.
Patent Information
- Application Number
- CN202420924674.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-04-30
AI Technical Summary
In existing cement kilns, the heat of high-temperature gases cannot be effectively utilized, resulting in waste of energy. At the same time, NOx cannot be removed, and a large amount of ammonia water is required to be removed, which affects the working efficiency of the combustion furnace.
A self-nitrogenation furnace for utilizing waste heat and controlling combustion of cement kilns is designed, including a self-nitrogenation furnace body, a decomposition furnace, a sixth-level cyclone cylinder, a fourth-level cyclone cylinder, a fifth-level cyclone cylinder and a rotary kiln. The coal powder is sprayed into the coal feeding point, and gasified at high temperature and burned to generate CO to remove NOx and reduce dependence on ammonia water.
It effectively utilizes the heat of the high-temperature gas at the tail of the cement kiln, reduces the dependence on ammonia, reduces NOx emission concentration, meets ultra-low emission standards, reduces environmental pollution, and saves ammonia water resources.
Smart Images
Figure CN222688807U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of self-denitrification furnaces, in particular to a self-denitrification furnace that utilizes waste heat from a cement kiln and controls combustion. Background Art
[0002] The decomposition furnace uses high-temperature tertiary air to ignite the injected coal powder, generating a large amount of heat, which allows the CaCO3 in the cement raw material to decompose rapidly, thus creating good conditions for calcination in the rotary kiln.
[0003] The temperature of the gas at the tail end of the cement kiln is about 1150℃, which carries a lot of heat. In order to make full use of this part of heat, the material with a temperature of 870℃ separated from the five-stage cyclone is mixed with it and fully heat exchanged. After the material is heated, it enters the rotary kiln for calcination, thus saving coal.
[0004] The gas in the cement kiln carries a large amount of NOx gas, which is toxic and needs to be removed. When the waste heat of the cement kiln is used, the coal powder is sprayed into the bottom of the self-denitrification furnace through precise controlled combustion. The whole cement kiln waste heat is used, the self-denitrification furnace and the six-stage cyclone cylinder are used as the reduction zone. The coal powder is gasified and burned at high temperature to generate a large amount of CO, which can effectively remove NOx.
[0005] In the prior art, the product structure is unreasonable, and there is no six-stage cyclone cylinder. The heat of the high-temperature gas at the tail of the cement kiln cannot be effectively utilized, resulting in energy waste. In the prior art, there is no coal powder fuel reduction area, and the NOx carried by the gas in the cement kiln cannot be removed, resulting in a high concentration of NOx at the outlet of the decomposition furnace. A large amount of ammonia water is required to remove it, reducing the working efficiency of the combustion furnace. Therefore, a cement kiln waste heat utilization and precise control combustion self-denitrification furnace is needed.
[0006] Therefore, it is proposed to utilize the waste heat of cement kiln and control the combustion in denitrification furnace. Utility Model Content
[0007] The purpose of the utility model is to avoid using a large amount of ammonia water for denitrification, further reduce pollution to the environment, be environmentally friendly, and save ammonia water resources. The application provides a cement kiln waste heat utilization and controlled combustion self-denitrification furnace.
[0008] The technical solution adopted by the utility model is as follows:
[0009] A self-denitrification furnace for utilizing waste heat from a cement kiln and controlling combustion comprises a self-denitrification furnace body, a decomposition furnace, a six-stage cyclone barrel, a four-stage cyclone barrel, a five-stage cyclone barrel and a rotary kiln. The bottom end of the self-denitrification furnace body is connected to a kiln tail smoke chamber of the rotary kiln through a pipeline, and one end of the self-denitrification furnace body away from the kiln tail smoke chamber is connected to the six-stage cyclone barrel. The upper internal volume of the decomposition furnace is connected to the upper internal volume of the six-stage cyclone barrel through a pipeline, and the bottom internal volume of the decomposition furnace is connected to a tertiary air duct.
[0010] Furthermore, the outer walls on both sides of the lower end of the self-denitrification furnace body are provided with a first coal feeding point and a second coal feeding point.
[0011] Furthermore, a third coal feeding point is provided on the outer wall of the lower end of the decomposition furnace.
[0012] Furthermore, a five-stage cyclone discharge point is installed at the bottom end of the five-stage cyclone, and the bottom internal cavity of the five-stage cyclone discharge point is connected with the bottom internal cavity of the self-denitrification furnace body through a pipeline.
[0013] Furthermore, a fourth-stage cyclone discharge point is installed at the bottom end of the fourth-stage cyclone barrel, and the bottom internal volume of the fourth-stage cyclone discharge point is connected with the lower internal volume of the decomposition furnace through a pipeline.
[0014] Furthermore, a six-stage cyclone discharge point is installed at the bottom end of the six-stage cyclone barrel, and the internal cavity at the bottom end of the six-stage cyclone discharge point is connected with the internal cavity of the kiln tail smoke chamber through a pipeline.
[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:
[0016] In the utility model, the material enters the bottom of the decomposition furnace from the fourth-stage cyclone cylinder through the fourth-stage cyclone discharge point, the airflow from the tertiary air duct brings up the material and transports it to the sixth-stage cyclone cylinder, the mixture of gas and material enters the sixth-stage cyclone cylinder, gas and material separation occurs inside the sixth-stage cyclone cylinder, the material enters the rotary kiln through the kiln tail smoke chamber along the sixth-stage cyclone discharge point of the sixth-stage cyclone cylinder for calcination, and the gas refluxes into the decomposition furnace through the self-denitrification furnace body; at the same time, gas and material separation occurs inside the fifth-stage cyclone cylinder, the material enters the bottom of the self-denitrification furnace body along the fifth-stage cyclone discharge point, and the material After the material enters, it is fully mixed and heat-exchanged with the gas entering the self-denitrification furnace body; the self-denitrification furnace body is connected through the kiln tail smoke chamber, and the coal powder and the material inside the six-stage cyclone cylinder enter the self-denitrification furnace body. After the coal powder is gasified in the self-denitrification furnace body, almost all of the NOx is reduced to N2, thus reducing the amount of ammonia water required for reducing NOx, so that only a small amount of ammonia water is needed to reduce the NOx emission concentration to the ultra-low emission standard. The use of the self-denitrification furnace body avoids the use of a large amount of ammonia water for denitrification, further reducing pollution to the environment, being environmentally friendly, and saving ammonia water resources. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0018] Markings in the figure: 1-self-denitrification furnace body, 2-kiln tail smoke chamber, 3-decomposition furnace, 4-sixth-stage cyclone cylinder, 5-sixth-stage cyclone cylinder unloading point, 6-fourth-stage cyclone cylinder, 7-fifth-stage cyclone cylinder, 8-five-stage cyclone cylinder unloading point, 9-fourth-stage cyclone cylinder unloading point, 10-rotary kiln, 11-tertiary air duct, 12-coal feeding point one, 13-coal feeding point two, 14-coal feeding point three. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0020] Example:
[0021] Reference Figure 1The self-denitrification furnace for utilizing waste heat from cement kiln and controlling combustion comprises a self-denitrification furnace body 1, a decomposition furnace 3, a six-stage cyclone barrel 4, a four-stage cyclone barrel 6, a five-stage cyclone barrel 7 and a rotary kiln 10. The bottom end of the self-denitrification furnace body 1 is connected with a kiln tail smoke chamber 2 of the rotary kiln 10 through a pipeline, and one end of the self-denitrification furnace body 1 away from the kiln tail smoke chamber 2 is connected with the six-stage cyclone barrel 4. The upper inner cavity of the decomposition furnace 3 is connected with the upper inner cavity of the six-stage cyclone barrel 4 through a pipeline, and the lower inner cavity of the decomposition furnace 3 is connected with the upper inner cavity of the six-stage cyclone barrel 4. A tertiary air duct 11 is provided, and a fourth-stage cyclone discharge point 9 is installed at the bottom of the fourth-stage cyclone cylinder 6. The internal volume at the bottom of the fourth-stage cyclone discharge point 9 is connected with the internal volume at the lower end of the decomposition furnace 3 through a pipeline; specifically, the material enters the bottom of the decomposition furnace 3 from the fourth-stage cyclone cylinder 6 through the fourth-stage cyclone discharge point 9, and the airflow from the tertiary air duct 11 lifts the material and transports it to the sixth-stage cyclone cylinder 4, and the mixture of gas and material enters the sixth-stage cyclone cylinder 4, and gas and material separation occurs inside the sixth-stage cyclone cylinder 4.
[0022] Reference Figure 1 A six-stage cyclone discharge point 5 is installed at the bottom end of the six-stage cyclone barrel 4, and the internal cavity at the bottom end of the six-stage cyclone discharge point 5 is connected with the internal cavity of the kiln tail smoke chamber 2 through a pipeline. A five-stage cyclone discharge point 8 is installed at the bottom end of the five-stage cyclone barrel 7, and the internal cavity at the bottom end of the five-stage cyclone discharge point 8 is connected with the internal cavity at the bottom end of the self-denitrification furnace body 1 through a pipeline; specifically, the material enters the rotary kiln 10 through the kiln tail smoke chamber 2 along the six-stage cyclone discharge point 5 of the six-stage cyclone barrel 4 for calcination, and the gas refluxes through the self-denitrification furnace body 1 to enter the decomposition furnace 3; at the same time, gas and material separation are generated inside the five-stage cyclone 7, and the material moves along the five-stage cyclone The material discharge point 8 enters the bottom of the self-denitrification furnace body 1. After the material enters, it is fully mixed and heat-exchanged with the gas entering the self-denitrification furnace body 1; the self-denitrification furnace body 1 is connected through the kiln tail smoke chamber 2, and the coal powder and the material inside the six-stage cyclone cylinder 4 enter the self-denitrification furnace body 1. After the coal powder is gasified in the self-denitrification furnace body 1, almost all of the NOx is reduced to N2, thereby reducing the amount of ammonia water required for reducing NOx, so that only a small amount of ammonia water is needed to reduce the NOx emission concentration to the ultra-low emission standard. The use of the self-denitrification furnace body 1 avoids the use of a large amount of ammonia water for denitrification, further reduces pollution to the environment, is environmentally friendly, and saves ammonia water resources.
[0023] Reference Figure 1 The outer walls on both sides of the lower end of the self-denitrification furnace body 1 are provided with a coal feeding point 12 and a coal feeding point 2 13, and the outer wall of the lower end of the decomposition furnace 3 is provided with a coal feeding point 3 14; specifically, coal powder can be sprayed into the bottom of the self-denitrification furnace body 1 from the coal feeding point 12 and the coal feeding point 2 13, and can also be sprayed into the bottom of the decomposition furnace 3 from the coal feeding point 3 14.
[0024] The implementation principle of the embodiment of the cement kiln waste heat utilization and controlled combustion self-denitrification furnace of the present application is:
[0025] When the self-denitrification furnace body 1 is used, the material enters the bottom of the decomposition furnace 3 from the fourth-stage cyclone barrel 6 through the fourth-stage cyclone barrel unloading point 9, and the airflow from the tertiary air duct 11 lifts the material and transports it to the sixth-stage cyclone barrel 4. The mixture of gas and material enters the sixth-stage cyclone barrel 4, and the gas and material are separated inside the sixth-stage cyclone barrel 4. The material enters the rotary kiln 10 along the sixth-stage cyclone barrel unloading point 5 of the sixth-stage cyclone barrel 4 through the kiln tail smoke chamber 2 for calcination, while the gas refluxes through the self-denitrification furnace body 1 and enters the decomposition furnace 3; at the same time, the gas and material are separated inside the fifth-stage cyclone barrel 7, and the material enters the self-denitrification furnace along the fifth-stage cyclone barrel unloading point 8 At the bottom of the furnace body 1, the material enters and is fully mixed and heat-exchanged with the gas entering the self-denitrification furnace body 1; the self-denitrification furnace body 1 is connected through the kiln tail smoke chamber 2, and the coal powder and the material inside the six-stage cyclone cylinder 4 enter the self-denitrification furnace body 1. After the coal powder is gasified in the self-denitrification furnace body 1, almost all of the NOx is reduced to N2, thereby reducing the amount of ammonia water required for reducing NOx, so that only a small amount of ammonia water is needed to reduce the NOx emission concentration to the ultra-low emission standard. The use of the self-denitrification furnace body 1 avoids the use of a large amount of ammonia water for denitrification, further reduces pollution to the environment, is environmentally friendly, and saves ammonia water resources.
[0026] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A self-denitrification furnace for utilizing waste heat from a cement kiln and controlling combustion, comprising a self-denitrification furnace body (1), a decomposition furnace (3), a six-stage cyclone barrel (4), a four-stage cyclone barrel (6), a five-stage cyclone barrel (7) and a rotary kiln (10), characterized in that: The bottom end of the self-denitrification furnace body (1) is connected to the kiln tail smoke chamber (2) of the rotary kiln (10) through a pipeline, and the end of the self-denitrification furnace body (1) away from the kiln tail smoke chamber (2) is connected to the six-stage cyclone barrel (4), and the upper end internal cavity of the decomposition furnace (3) is connected to the upper end internal cavity of the six-stage cyclone barrel (4) through a pipeline, and the bottom end internal cavity of the decomposition furnace (3) is connected to a tertiary air duct (11).
2. The cement kiln waste heat utilization and controlled combustion self-denitrification furnace according to claim 1, characterized in that: Coal feeding point 1 (12) and coal feeding point 2 (13) are arranged on the outer walls on both sides of the lower end of the self-denitrification furnace body (1).
3. The cement kiln waste heat utilization and controlled combustion self-denitrification furnace according to claim 1, characterized in that: The outer wall of the lower end of the decomposition furnace (3) is provided with a coal feeding point three (14).
4. The cement kiln waste heat utilization and controlled combustion self-denitrification furnace according to claim 1, characterized in that: A five-stage cyclone discharge point (8) is installed at the bottom end of the five-stage cyclone discharge point (7), and the bottom internal cavity of the five-stage cyclone discharge point (8) is connected to the bottom internal cavity of the self-denitrification furnace body (1) through a pipeline.
5. The cement kiln waste heat utilization and controlled combustion self-denitrification furnace according to claim 1, characterized in that: A fourth-stage cyclone discharge point (9) is installed at the bottom end of the fourth-stage cyclone barrel (6), and the internal volume at the bottom end of the fourth-stage cyclone discharge point (9) is connected to the internal volume at the lower end of the decomposition furnace (3) through a pipeline.
6. The cement kiln waste heat utilization and controlled combustion self-denitrification furnace according to claim 1, characterized in that: A six-stage cyclone discharge point (5) is installed at the bottom end of the six-stage cyclone barrel body (4), and the internal cavity at the bottom end of the six-stage cyclone discharge point (5) is connected to the internal cavity of the kiln tail smoke chamber (2) through a pipeline.