A method of operating a rotary kiln system

Abstract

The present application belongs to the technical field of rotary kiln, in particular to a working method of rotary kiln system, comprising kiln tail cover, rotary kiln and kiln head cover which are sequentially connected along the feeding direction, the kiln tail cover is connected with the second dust removal system, the second valve is arranged between the kiln tail cover and the second dust removal system, the second dust removal system is connected with the induced draft fan, the kiln head cover is connected with the first dust removal system, the first valve is arranged between the kiln head cover and the first dust removal system, and the first dust removal system is connected with the second dust removal system. When using, the present application only needs to ignite the metallic aluminum in the aluminum ash by the ignition agent at the beginning, the metallic aluminum generates the aluminum thermal reaction to ignite more aluminum ash, reaches the required temperature of the rotary kiln, thereby realizes the aluminum ash combustion to generate the product, does not need the participation of the natural gas, saves the production cost, reduces the emission of carbon dioxide, and the production is safer; by arranging two dust removal systems, the heat dissipation pressure and the dust removal pressure of the single dust removal system are reduced.

Description

Technical Field

[0001] This invention belongs to the field of rotary kiln technology, and particularly relates to a working method of a rotary kiln system. Background Technology

[0002] A rotary kiln is a type of industrial furnace that operates by rotating a calcining furnace. Rotary kilns can be categorized based on the materials they process, such as cement kilns, metallurgical and chemical kilns, and lime kilns. In recent years, with the continuous expansion of the industry, rotary kilns have also been widely used in environmental protection sectors such as waste incineration, solid waste treatment, sludge treatment, and waste salt treatment, demonstrating their wide range of applications.

[0003] In existing technologies, the processing of materials inside rotary kilns is mostly done by continuously feeding natural gas into the kiln through a burner and igniting it. The aluminum ash is burned under the action of the natural gas flame to generate products. This method requires a large amount of natural gas, resulting in high production costs. At the same time, it also produces a large amount of carbon dioxide, causing environmental pollution. Natural gas is a flammable and explosive gas, and the use of natural gas will have higher requirements for safe production.

[0004] Meanwhile, in existing technologies, exhaust gas is generally directly introduced into the dust removal system, and the high temperature of the exhaust gas puts a great pressure on the dust removal system in terms of heat dissipation and dust removal. Summary of the Invention

[0005] The purpose of this invention is to provide a working method for a rotary kiln system to solve the above-mentioned problems. By igniting aluminum ash with an igniter, natural gas is not required, thereby saving production costs and reducing carbon dioxide emissions.

[0006] To achieve the above objectives, the present invention provides the following solution: A rotary kiln system includes a kiln tail hood, a rotary kiln, and a kiln head hood connected sequentially along the feeding direction. The kiln tail hood is connected to a second dust removal system, and a second valve is provided between the kiln tail hood and the second dust removal system. The second dust removal system is connected to an induced draft fan. The kiln head hood is connected to a first dust removal system, and a first valve is provided between the kiln head hood and the first dust removal system. The first dust removal system is connected to the second dust removal system.

[0007] Preferably, the first dust removal system includes several dust collection chambers, which are arranged at equal intervals. The dust collection chambers located at both ends are respectively connected to the kiln head hood and the second dust removal system, and adjacent dust collection chambers are connected by dust removal pipes.

[0008] Preferably, the dust removal pipe includes two first connecting pipes, which are connected to the dust settling chamber, and the two first connecting pipes are connected through a second connecting pipe, with the included angle between the first connecting pipe and the second connecting pipe being 60°-75°.

[0009] Preferably, it includes the following steps: S1. Lay an aluminum ash layer inside the rotary kiln; S2. Several piles of ignition agent are stacked on top of the aluminum ash layer; S3. Close the first valve, open the second valve, and the induced draft fan blows counter-current air into the rotary kiln and manually ignites the igniter; S4. After ignition is completed, open the first valve and close the second valve, and the induced draft fan circulates air into the rotary kiln. S5. When ring formation occurs in the rotary kiln, the position of the high-temperature zone in the rotary kiln is changed by controlling the airflow direction, thereby achieving ring crossing and removing the rings.

[0010] Preferably, in step S1, the aluminum ash layer is laid at one end of the rotary kiln near the kiln tail cover.

[0011] Preferably, in step S2, several piles of the igniter are arranged at equal intervals along the length of the aluminum ash layer.

[0012] Preferably, in step S3, the worker enters the rotary kiln from the kiln head hood and ignites the igniter along the direction from the kiln tail hood to the kiln head hood. After ignition is completed, the worker exits the rotary kiln from the kiln head hood.

[0013] Preferably, in step S3, the combustion status of the aluminum ash inside the rotary kiln is detected by a temperature sensor, and the combustion status of the aluminum ash is adjusted by rotating the rotary kiln.

[0014] Preferably, in step S5, when the ring is located on the side of the aluminum ash combustion field near the kiln tail hood, the second valve is opened and the first valve is closed, and the induced draft fan blows counter-current air into the rotary kiln; when the ring is located on the side of the aluminum ash combustion field near the kiln head hood, the first valve is opened and the second valve is closed, and the induced draft fan blows forward air into the rotary kiln. By changing the airflow direction of the induced draft fan through the first and second valves, the ventilation direction inside the rotary kiln is changed, causing the aluminum ash combustion field to shift and the position of the high-temperature zone of the aluminum ash to change, thereby achieving the shedding of the ring and removing the ring from the inner wall of the rotary kiln.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: This invention changes the existing technology where the processing of materials in rotary kilns is mostly done by continuously feeding natural gas into the rotary kiln through a burner and igniting it, with the aluminum ash being calcined and producing products under the action of the natural gas flame. This invention only requires igniting the metallic aluminum in the aluminum ash with an igniter at the beginning. The metallic aluminum undergoes an aluminothermic reaction, which in turn ignites more aluminum ash, reaching the temperature required by the rotary kiln, thereby realizing the combustion of aluminum ash to produce products. The process flow of this invention does not require the participation of natural gas, saving production costs, reducing carbon dioxide emissions, and avoiding the dangers of using natural gas. By adding a first dust removal system on one side of the rotary kiln, when the air is ventilated in the co-current direction, the dust enters the first dust removal system for intermediate dust collection and heat dissipation, reducing the heat dissipation pressure and dust removal pressure of a single dust removal system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the first dust removal system.

[0017] Among them, 1. Kiln head hood; 2. First valve; 3. Rotary kiln; 4. Exhaust fan; 5. Kiln tail hood; 6. Second valve; 7. Second dust removal system; 8. Dust settling chamber; 9. Dust removal pipeline; 901. First connecting pipeline; 902. Second connecting pipeline. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1-2The present invention provides a rotary kiln system, comprising a kiln tail hood 5, a rotary kiln 3, and a kiln head hood 1 connected sequentially along the feeding direction. The kiln tail hood 5 is connected to a second dust removal system 7, and a second valve 6 is provided between the kiln tail hood 5 and the second dust removal system 7. The second dust removal system 7 is connected to an induced draft fan 4. The kiln head hood 1 is connected to a first dust removal system, and a first valve 2 is provided between the kiln head hood 1 and the first dust removal system. The first dust removal system is connected to the second dust removal system 7.

[0021] The present invention adds a first dust removal system on one side of the rotary kiln 3. When the air is ventilated in the same direction, the smoke and dust enter the first dust removal system for intermediate dust collection and heat dissipation, thereby reducing the heat dissipation pressure and dust removal pressure of a single dust removal system.

[0022] The second dust removal system 7 includes a dust removal chamber and dust removal filter bags, which are existing technologies and will not be described in detail here.

[0023] The scheme is further optimized. The first dust removal system includes several dust collection chambers 8, which are set at equal intervals. The dust collection chambers 8 at both ends are connected to the kiln head hood 1 and the second dust removal system 7, respectively. Adjacent dust collection chambers 8 are connected by dust removal pipes 9.

[0024] The scheme is further optimized. The dust removal pipe 9 includes two first connecting pipes 901. The first connecting pipes 901 are connected to the dust settling chamber 8. The two first connecting pipes 901 are connected through a second connecting pipe 902. The included angle between the first connecting pipe 901 and the second connecting pipe 902 is 60°-75°.

[0025] The angle between the first connecting pipe 901 and the second connecting pipe 902 is 60°-75°, which can prevent the accumulation of smoke and dust. The material of the dust removal pipe 9 is preferably a metal with high thermal conductivity. The two first connecting pipes 901 are connected by the second connecting pipe 902, which increases the length of the dust removal pipe 9. The dust removal pipe 9 has a longer contact time with the exhaust gas, which can better dissipate heat and reduce the heat dissipation pressure of the second dust removal system 7.

[0026] A method for operating a rotary kiln system includes the following steps: S1. Lay an aluminum ash layer inside the rotary kiln 3; S2. Several piles of ignition agent are stacked on top of the aluminum ash layer; S3. Close the first valve 2, open the second valve 6, and the induced draft fan 4 circulates counter-current air into the rotary kiln 3 and ignites the igniter manually. S4. After ignition is completed, open the first valve 2, close the second valve 6, and the induced draft fan 4 circulates air into the rotary kiln 3. S5. When ring formation occurs in rotary kiln 3, the position of the high-temperature zone in rotary kiln 3 is changed by controlling the airflow direction, thereby achieving ring crossing and removing the ring.

[0027] In this invention, the preferred igniter is charcoal. Initially, charcoal ignites the metallic aluminum in the aluminum ash, causing an aluminothermic reaction that ignites more aluminum ash, reaching the temperature required by the rotary kiln, thereby achieving the combustion of aluminum ash to generate products. This invention does not require the use of natural gas, saving production costs, reducing carbon dioxide emissions, and avoiding the dangers of using natural gas. Winds in the same direction as the feed direction are called downwind, and winds in the opposite direction are called headwind. When rings form inside the rotary kiln 3, the airflow direction of the induced draft fan 4 is controlled by the first valve 2 and the second valve 6, thereby changing the ventilation direction inside the rotary kiln 3, causing the combustion field of the aluminum ash to shift, the position of the high-temperature zone to change, and achieving cross-ring formation, thus removing the rings from the inner wall of the rotary kiln.

[0028] In a further optimized scheme, in step S1, an aluminum ash layer is laid on one end of the rotary kiln 3 near the kiln tail cover 5.

[0029] The aluminum ash layer is 19 meters long, 40 centimeters thick, and 80 centimeters wide along the rotary kiln 3.

[0030] To further optimize the scheme, in step S2, several piles of igniter are set at equal intervals along the length of the aluminum ash layer.

[0031] To further optimize the scheme, in step S3, the worker enters the rotary kiln 3 from the kiln head hood 1 and ignites the igniter along the direction from the kiln tail hood 5 to the kiln head hood 1. After ignition is completed, the worker exits the rotary kiln 3 from the kiln head hood 1.

[0032] To further optimize the scheme, in step S3, the combustion status of aluminum ash inside rotary kiln 3 is detected by a temperature sensor, and the combustion status of aluminum ash is adjusted by rotating rotary kiln 3.

[0033] To further optimize the scheme, in step S5, when the ring is located on the side of the aluminum ash combustion field near the kiln tail hood 5, the second valve 6 is opened and the first valve 2 is closed, and the induced draft fan 4 blows counter-current air into the rotary kiln 3; when the ring is located on the side of the aluminum ash combustion field near the kiln head hood 1, the first valve 2 is opened and the second valve 6 is closed, and the induced draft fan 4 blows forward air into the rotary kiln 3. By changing the airflow direction of the induced draft fan 4 through the first valve 2 and the second valve 6, the ventilation direction inside the rotary kiln 3 is changed, causing the aluminum ash combustion field to move and the position of the high-temperature zone of the aluminum ash to change, thereby achieving the shedding of the ring and removing the ring from the inner wall of the rotary kiln 3.

[0034] First, aluminum ash is fed into the front end of rotary kiln 3 at kiln tail hood 5 and laid in layers. Several charcoal piles are laid on top of the aluminum ash layer, and several charcoal piles are set at intervals. The kiln tail hood 5 is connected to the induced draft fan 4. The first valve 2 is closed and the second valve 6 is opened. The induced draft fan 4 blows counter-current air into the rotary kiln 3. The worker enters the rotary kiln 3 from the kiln head hood 1 and ignites the aluminum ash through the charcoal pile along the direction from the kiln tail hood 5 to the kiln head hood 1 of the rotary kiln 3. After ignition, the worker exits the rotary kiln 3. At the same time, counter-current ventilation continues. The combustion status of the aluminum ash in the rotary kiln is detected by the temperature sensor, and the combustion status of the aluminum ash is adjusted by rotating the rotary kiln 3. After counter-current ventilation, open the first valve 2 and close the second valve 6 to change the airflow direction inside the rotary kiln 3, allowing for co-current ventilation. This co-current ventilation also prevents dusty aluminum ash from clogging the dust removal pipe 9 and improves heat dissipation, reducing the heat dissipation pressure on the second dust removal system 7.

[0035] When rings form inside the rotary kiln 3, the airflow direction of the induced draft fan 4 is changed, thereby changing the ventilation direction inside the rotary kiln 3. This causes the combustion field of the aluminum ash to shift, moving the combustion field of the aluminum ash to the ring formation location. The position of the high-temperature zone changes, achieving ring crossing and removing the rings from the inner wall of the rotary kiln 3.

[0036] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for operating a rotary kiln system, characterized in that, Includes the following steps: S1. Lay an aluminum ash layer inside the rotary kiln (3); S2. Several piles of ignition agent are stacked on top of the aluminum ash layer; S3. Close the first valve (2), open the second valve (6), and the induced draft fan (4) circulates counter-current air into the rotary kiln (3) and ignites the igniter manually. S4. After ignition is completed, open the first valve (2), close the second valve (6), and the induced draft fan (4) circulates air into the rotary kiln (3). S5. When ring formation occurs in the rotary kiln (3), the position of the high-temperature zone in the rotary kiln (3) is changed by controlling the air direction, so as to achieve ring crossing and remove the ring. In step S5, when the ring is located on the side of the aluminum ash combustion field close to the kiln tail hood (5), the second valve (6) is opened and the first valve (2) is closed, and the induced draft fan (4) blows counter-current air into the rotary kiln (3); when the ring is located on the side of the aluminum ash combustion field close to the kiln head hood (1), the first valve (2) is opened and the second valve (6) is closed, and the induced draft fan (4) blows forward air into the rotary kiln (3). By changing the air direction of the induced draft fan (4) through the first valve (2) and the second valve (6), the ventilation direction inside the rotary kiln (3) is changed, causing the aluminum ash combustion field to move and the high temperature zone of the aluminum ash to change position, thereby achieving the shedding of the ring and removing the ring from the inner wall of the rotary kiln (3); The rotary kiln system includes: a kiln tail hood (5), a rotary kiln (3), and a kiln head hood (1) connected sequentially along the feeding direction. The kiln tail hood (5) is connected to a second dust removal system (7). A second valve (6) is provided between the kiln tail hood (5) and the second dust removal system (7). The second dust removal system (7) is connected to an induced draft fan (4). The kiln head hood (1) is connected to a first dust removal system. A first valve (2) is provided between the kiln head hood (1) and the first dust removal system. The first dust removal system is connected to the second dust removal system (7).

2. The operating method of a rotary kiln system according to claim 1, characterized in that, The first dust removal system includes several dust collection chambers (8), which are arranged at equal intervals. The dust collection chambers (8) located at both ends are connected to the kiln head hood (1) and the second dust removal system (7), respectively. Adjacent dust collection chambers (8) are connected by dust removal pipes (9).

3. The operating method of a rotary kiln system according to claim 2, characterized in that, The dust removal pipe (9) includes two first connecting pipes (901), which are connected to the dust settling chamber (8). The two first connecting pipes (901) are connected through a second connecting pipe (902). The included angle between the first connecting pipe (901) and the second connecting pipe (902) is 60°-75°.

4. The operating method of a rotary kiln system according to claim 1, characterized in that, In step S1, the aluminum ash layer is laid on one end of the rotary kiln (3) near the kiln tail cover (5).

5. The operating method of a rotary kiln system according to claim 1, characterized in that, In step S2, several piles of the igniter are arranged at equal intervals along the length of the aluminum ash layer.

6. The operating method of a rotary kiln system according to claim 1, characterized in that, In step S3, the worker enters the rotary kiln (3) from the kiln head cover (1) and ignites the igniter along the direction from the kiln tail cover (5) to the kiln head cover (1). After ignition, the worker exits the rotary kiln (3) from the kiln head cover (1).

7. The operating method of a rotary kiln system according to claim 1, characterized in that, In step S3, the combustion status of the aluminum ash in the rotary kiln (3) is detected by a temperature sensor, and the combustion status of the aluminum ash is adjusted by rotating the rotary kiln (3).

Images