Method for generating thermal insulation cotton material from municipal solid waste fly ash by joule heating

Abstract

The application discloses a method for generating thermal insulation cotton material through Joule heating of household garbage fly ash, and relates to the technical field of resource utilization of household garbage incineration fly ash, and comprises the following steps: S1, first grinding and sieving; household garbage combustion fly ash collected is ground through a ball mill, and then sieved through a screening device to ensure the uniformity of the reaction; S2, first-stage Joule heating; the sieved fly ash is laid on a graphite plate and subjected to first-stage Joule heating pretreatment. When the application is used, the limiting rod is driven by the screen to move up and down, slide along the inner wall of the wave groove and swing left and right, the end of the screw rod moves along the inner wall of the inner helical groove rod as the screen swings left and right, the semicircular block slides along the inner wall of the inner helical groove rod, the screw rod rotates and the scraper moves along the inner wall of the screen, so that the fly ash in the screen is scraped, and the screening speed of the fly ash is increased.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology of fly ash from municipal solid waste incineration, and in particular to a method for generating thermal insulation cotton material from municipal solid waste fly ash through Joule heating. Background Technology

[0002] Municipal solid waste incineration has gradually become the main method for handling municipal solid waste in major cities across China. However, during the incineration process, some fly ash is emitted from the flue gas purification system. This fly ash contains various harmful heavy metals such as lead, chromium, and cadmium, which are produced during the incineration process. It is a hazardous waste that requires safe and proper disposal. Landfilling of incineration fly ash after solidification and stabilization not only occupies a large amount of land resources, but also poses a risk of hazardous substances leaching from landfills. Thorough stabilization, harmless treatment, and resource recovery are the ultimate solutions.

[0003] Currently, some fly ash needs to be screened during processing. However, when fly ash falls directly onto the screen, it tends to accumulate on the screen, which can affect the screening speed. Summary of the Invention

[0004] To address the problem mentioned above that existing methods require screening fly ash during processing, but fly ash tends to accumulate directly on the screen when it falls on it, thus affecting the screening speed, this invention provides a method for generating thermal insulation cotton material from municipal solid waste fly ash through Joule heating.

[0005] This invention provides a method for generating thermal insulation material from municipal solid waste fly ash through Joule heating, employing the following technical solution: A method for generating thermal insulation material from municipal solid waste fly ash via Joule heating includes the following steps: S1: First grinding and sieving; The fly ash from the collected municipal solid waste is ground in a ball mill and then sieved through a screening device to ensure the uniformity of the reaction. S2: First stage Joule heating; The sieved fly ash is spread on a graphite plate for the first stage of Joule heating pretreatment, and then most of the heavy metals, chlorine and dioxins are removed by vacuum distillation equipment. S3: Second grinding and sieving; The fly ash after the Joule reaction is collected and mixed with quartz sand, kaolin and iron ore. It is then ground again in a ball mill and sieved through a screening device. S4: Second stage Joule heating; The sieved fly ash is spread out on a graphite plate again for a second stage of Joule heating. After being melted at high temperature, it produces thermal insulation cotton material.

[0006] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash through Joule heating, the screening equipment includes a collection box, a cam rod rotatably arranged inside the collection box, a motor fixedly arranged on the outer wall of the collection box, the rotating shaft of the motor being inserted into the collection box and fixedly connected to one end of the cam rod, corrugated grooves being provided on both the front and rear sides of the inner wall of the collection box, vertical grooves being provided on both the left and right sides of the inner wall of the collection box, an inner spiral groove rod being slidably arranged on the inner wall of the vertical groove, and a screen being movably arranged inside the collection box, the bottom surface of the screen slidingly engaging with the outer wall of the cam rod; Limiting rods are provided on both the front and rear sides of the screen. The end of the limiting rod away from the screen is located in the corrugated groove and slides in cooperation with the inner wall of the corrugated groove. A screw is rotatably provided on the inner wall of the screen. The two ends of the screw pass through the screen and are respectively inserted into two inner spiral groove rods. A semi-circular block is fixedly provided at the end of the screw inserted into the inner spiral groove rod. The semi-circular block slides in cooperation with the inner wall of the inner spiral groove rod. A scraper is threaded onto the outer wall of the screw. The scraper slides in cooperation with the inner wall of the screen.

[0007] The above technical solution first involves grinding the fly ash using a ball mill. The ground fly ash is then transported to a collection box and screened. A motor drives a cam rod to rotate, which in turn pushes the screen to move up and down. As the screen moves, a limit rod moves up and down and slides along the inner wall of the corrugated groove, causing the screen to sway left and right on the inner wall of the collection box.

[0008] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, a discharge port is provided at the lower end of the side wall of the collection box, a feed port is provided on the top surface of the collection box, a second spring is fixedly provided on the inner bottom wall of the collection box, a graphite plate is fixedly provided at the upper end of the second spring, and the graphite plate is movably arranged inside the collection box.

[0009] The above technical solution allows fly ash to enter the collection box through the feed inlet. After the fly ash is screened, it is guided by a graphite plate and then discharged through the discharge outlet.

[0010] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, inclined plates are hinged to both ends of the screen. The end of the inclined plate away from the screen is inclined upward and slides in cooperation with the inner wall of the collection box. A first spring is fixedly installed on the bottom surface of the inclined plate, and the lower end of the first spring is fixedly connected to the outer wall of the screen.

[0011] With the above technical solution, when fly ash falls into the collection box, the inclined plate causes all the fly ash to fall into the screen for screening, and the first spring causes the end of the inclined plate away from the screen to always be in contact with the inner wall of the collection box.

[0012] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, a striking block is fixedly installed on the side wall of the inner wall of the collection box, and when the graphite plate moves upward, the striking block collides with the top surface of the graphite plate.

[0013] With the above technical solution, as the cam rod rotates, the cam rod separates from the graphite plate. At this time, the graphite plate is pushed upward by the second spring and collides with the striking block to generate vibration.

[0014] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, both ends of the graphite plate are connected to electrodes and connected to a negative pressure gas collection device.

[0015] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, the mass ratio of fly ash to quartz sand, kaolin, and iron ore is 45-60%, 20-30%, 20-30%, and 8-10%, respectively.

[0016] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, the collected municipal solid waste combustion fly ash is ground in a ball mill and then passed through a 200-mesh sieve. The fly ash is then mixed with quartz sand, kaolin, and iron ore and ground again before being passed through a 250-mesh sieve.

[0017] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, the thickness of the fly ash laid on the graphite plate is 2-4 mm, and the thickness of the fly ash mixed with quartz sand, kaolin, and iron ore spread on the graphite plate is 1-3 mm.

[0018] Optionally, in the above-mentioned method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating, the Joule heating temperature in the first stage is controlled at 1200-1400℃, the number of Joule heating cycles is 1-3, and the Joule heating time is 1 second; the Joule heating temperature in the second stage is controlled at 1600-2000℃, and the Joule heating time is >30 seconds.

[0019] In summary, the present invention has at least one of the following beneficial effects: When the screen moves the limiting rod up and down and slides along the inner wall of the corrugated groove and sways left and right, the left and right swaying of the screen causes the end of the screw to move along the inner wall of the inner spiral groove rod. At the same time, the semi-circular block slides along the inner wall of the inner spiral groove rod, causing the screw to rotate and causing the scraper to move along the inner wall of the screen, which facilitates the scraping of fly ash in the screen and increases the screening speed of fly ash. The process described in this application is simple and easy to operate, involving only secondary Joule heating and secondary grinding and sieving. It effectively removes pollutants such as heavy metals, chlorine, and dioxins from fly ash, and the prepared insulation material has high purity. The Joule heating time is short, and the energy consumption is reduced compared to traditional electric arc heating. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the present invention; Figure 2 This is a three-dimensional structural diagram of the screening device of the present invention; Figure 3 This is a three-dimensional structural cross-sectional view of the screening device of the present invention; Figure 4 This is a partial three-dimensional unfolded cross-sectional view of the screening device of the present invention; Figure 5 This is a partial three-dimensional cross-sectional view of the screening device of the present invention.

[0021] In the diagram: 1. Screening equipment; 2. Collection box; 3. Cam rod; 4. Motor; 5. Corrugated trough; 6. Vertical trough; 7. Inner spiral groove rod; 8. Screen; 9. Limiting rod; 10. Screw; 11. Semicircular block; 12. Scraper; 13. Discharge port; 14. Feed port; 15. Second spring; 16. Graphite plate; 17. Inclined plate; 18. First spring; 19. Striking block. Detailed Implementation

[0022] The following is in conjunction with the appendix Figures 1-5 The present invention will be described in further detail below.

[0023] Please refer to the attached diagram in the instruction manual. Figures 1-5 The present invention provides an embodiment of a method for generating thermal insulation cotton material from municipal solid waste fly ash through Joule heating, comprising the following steps: Step 1: First grinding and sieving; The collected municipal solid waste fly ash is ground in a ball mill and then sieved through screening equipment 1 to ensure the uniformity of the reaction. The ball mill is a high manganese steel lined ball mill. Step Two: First Stage Joule Heating; The sieved fly ash is spread on graphite plate 16 with a thickness of 2-4 mm. The first stage of Joule heating pretreatment is carried out. The Joule heating temperature is controlled at 1200-1400℃, the number of Joule heating cycles is 1-3, and the Joule heating time is 1 second. Then, most of the heavy metals, chlorine and dioxins are removed by vacuum distillation equipment. Step 3: Second grinding and sieving; The fly ash after the Joule reaction is collected and mixed with quartz sand, kaolin and iron ore. The mass ratio of fly ash to quartz sand, kaolin and iron ore is 45-60%, 20-30%, 20-30% and 8-10%, respectively. The mixture is then ground again in a ball mill and then sieved through screening equipment 1. Step 4: Second stage Joule heating; The sieved fly ash is spread again on the graphite plate 16. The fly ash, quartz sand, kaolin, and iron ore are mixed and spread on the graphite plate 16 to a thickness of 1-3 mm. The second stage of Joule heating is then carried out. The Joule heating temperature is controlled at 1600-2000℃ and the Joule heating time is >30s. After high-temperature melting, the insulation cotton material is obtained. The graphite plate 16 is connected to the electrode and to the negative pressure gas collection device. The electrode is connected to both ends of the graphite plate 16 to conduct electricity, and then Joule heating is directly achieved through the conductivity of the graphite plate.

[0024] See the attached diagram in the instruction manual. Figures 2-5 The screening equipment 1 includes a collection box 2. A cam rod 3 is rotatably installed inside the collection box 2. A motor 4 is fixedly installed on the outer wall of the collection box 2. The rotating shaft of the motor 4 is inserted into the collection box 2 and fixedly connected to one end of the cam rod 3. Wave grooves 5 are opened on the front and rear sides of the inner wall of the collection box 2. Vertical grooves 6 are opened on the left and right sides of the inner wall of the collection box 2. An inner spiral groove rod 7 is slidably installed on the inner wall of the vertical groove 6. A screen 8 is movably installed inside the collection box 2. The bottom surface of the screen 8 slides in cooperation with the outer wall of the cam rod 3.

[0025] Limiting rods 9 are provided on both the front and rear sides of the screen 8. The end of the limiting rod 9 away from the screen 8 is located in the corrugated groove 5 and slides in cooperation with the inner wall of the corrugated groove 5. A screw 10 is rotatably provided on the inner wall of the screen 8. The two ends of the screw 10 pass through the screen 8 and are respectively inserted into two inner spiral groove rods 7. A semi-circular block 11 is fixedly provided at the end of the screw 10 inserted into the inner spiral groove rod 7. The semi-circular block 11 slides in cooperation with the inner wall of the inner spiral groove rod 7. A scraper 12 is threadedly sleeved on the outer wall of the screw 10. The scraper 12 slides in cooperation with the inner wall of the screen 8.

[0026] First, the fly ash is ground using a ball mill. The ground fly ash is then conveyed to the collection box 2 and screened through a screen 8. The motor 4 drives the cam rod 3 to rotate. When the cam rod 3 rotates, it pushes the screen 8 to move up and down. As the screen 8 moves up and down, it drives the limiting rod 9 to slide along the inner wall of the corrugated groove 5, causing the screen 8 to sway left and right on the inner wall of the collection box 2. As the screen 8 sways left and right, it causes the end of the screw 10 to move along the inner wall of the inner spiral groove rod 7. At the same time, the semi-circular block 11 slides along the inner wall of the inner spiral groove rod 7, causing the screw 10 to rotate and causing the scraper 12 to move along the inner wall of the screen 8. This facilitates the scraping of the fly ash in the screen 8, thereby increasing the screening speed of the fly ash.

[0027] A discharge port 13 is provided at the lower end of the side wall of the collection box 2, and a feed port 14 is provided on the top surface of the collection box 2. A second spring 15 is fixedly installed on the inner bottom wall of the collection box 2, and a graphite plate 16 is fixedly installed at the upper end of the second spring 15. The graphite plate 16 is movably installed inside the collection box 2. The fly ash can enter the collection box 2 through the feed port 14. After the fly ash screening is completed, the fly ash is Joule heated by the graphite plate 16, and then the treated fly ash is discharged through the discharge port 13. The operator can use tools to scrape the fly ash off the graphite plate 16.

[0028] Both ends of the screen 8 are hinged with inclined plates 17. The end of the inclined plate 17 away from the screen 8 is inclined upward and slides in cooperation with the inner wall of the collection box 2. A first spring 18 is fixedly installed on the bottom surface of the inclined plate 17. The lower end of the first spring 18 is fixedly connected to the outer wall of the screen 8. When fly ash falls into the collection box 2, the inclined plate 17 causes all the fly ash to fall into the screen 8 for screening. The first spring 18 causes the end of the inclined plate 17 away from the screen 8 to always be in contact with the inner wall of the collection box 2, thereby reducing the possibility that some fly ash will fall directly onto the graphite plate 16 without screening.

[0029] A striking block 19 is fixedly installed on the side wall of the inner wall of the collection box 2. When the graphite plate 16 moves upward, the striking block 19 collides with the top surface of the graphite plate 16. As the cam rod 3 rotates, the cam rod 3 separates from the graphite plate 16. At this time, the graphite plate 16 is pushed upward by the second spring 15 and collides with the striking block 19 to generate vibration. When the cam rod 3 touches the graphite plate 16, the graphite plate 16 moves downward. This process is repeated to make the fly ash evenly shaken and spread on the graphite plate 16. Then, the fly ash is treated by Joule heating.

[0030] Specifically, the internal structure of screening equipment 1 is made of high-temperature resistant materials, such as 321H stainless steel.

[0031] See the attached diagram in the instruction manual. Figures 3-4After collection, the fly ash from the combustion of municipal solid waste is ground in a ball mill and then passed through a 200-mesh sieve 8. The fly ash is then mixed with quartz sand, kaolin, and iron ore and ground again before being passed through a 250-mesh sieve 8. The specifications of the sieve 8 can be changed.

[0032] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for generating thermal insulation material from municipal solid waste fly ash via Joule heating, characterized in that: Includes the following steps: S1: First grinding and sieving; The collected domestic waste was burned and the fly ash was ground in a ball mill and then sieved through a screening device (1) to ensure the uniformity of the reaction. S2: First stage Joule heating; The sieved fly ash is laid on a graphite plate (16) for the first stage of Joule heating pretreatment. Then, most of the heavy metals, chlorine and dioxins are removed by vacuum distillation equipment. The first stage of Joule heating temperature is controlled at 1200-1400℃, the number of Joule heatings is 1-3 times, and the Joule heating time is 1 second. S3: Second grinding and sieving; Collect the fly ash after the Joule reaction, add quartz sand, kaolin and iron ore to mix, grind again through a ball mill, and then sieve through a screening device (1); S4: Second stage Joule heating; After sieving, the fly ash is spread on the graphite plate (16) again for the second stage of Joule heating. After high-temperature melting, the thermal insulation cotton material is obtained. The second stage of Joule heating temperature is controlled at 1600-2000℃ and the Joule heating time is >30s. The screening device (1) in the above method includes a collection box (2), a cam rod (3) is rotatably arranged inside the collection box (2), a motor (4) is fixedly arranged on the outer wall of the collection box (2), the rotating shaft of the motor (4) is inserted into the collection box (2) and fixedly connected to one end of the cam rod (3), wave grooves (5) are opened on the front and rear sides of the inner wall of the collection box (2), vertical grooves (6) are opened on the left and right sides of the inner wall of the collection box (2), an inner spiral groove rod (7) is slidably arranged on the inner wall of the vertical groove (6), a screen (8) is movably arranged inside the collection box (2), and the bottom surface of the screen (8) is slidably engaged with the outer wall of the cam rod (3); Limiting rods (9) are provided on both the front and rear sides of the screen (8). The end of the limiting rod (9) away from the screen (8) is located in the wave groove (5) and slides in cooperation with the inner wall of the wave groove (5). A screw (10) is rotatably provided on the inner wall of the screen (8). The two ends of the screw (10) pass through the screen (8) and are respectively inserted into two inner spiral groove rods (7). A semi-circular block (11) is fixedly provided at the end of the screw (10) inserted into the inner spiral groove rod (7). The semi-circular block (11) slides in cooperation with the inner wall of the inner spiral groove rod (7). A scraper (12) is threaded onto the outer wall of the screw (10). The scraper (12) slides in cooperation with the inner wall of the screen (8).

2. The method for generating thermal insulation material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: The lower end of the side wall of the collection box (2) is provided with a discharge port (13), the top surface of the collection box (2) is provided with a feed port (14), the inner bottom wall of the collection box (2) is fixedly provided with a second spring (15), the upper end of the second spring (15) is fixedly provided with a graphite plate (16), and the graphite plate (16) is movably arranged inside the collection box (2).

3. The method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: Both ends of the screen (8) are hinged with inclined plates (17). The end of the inclined plate (17) away from the screen (8) is inclined upward and slides in cooperation with the inner wall of the collection box (2). A first spring (18) is fixedly provided on the bottom surface of the inclined plate (17). The lower end of the first spring (18) is fixedly connected to the outer wall of the screen (8).

4. The method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: A striking block (19) is fixedly installed on the side wall of the inner wall of the collection box (2). When the graphite plate (16) moves upward, the striking block (19) collides with the top surface of the graphite plate (16).

5. The method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: The graphite plate (16) is connected to the capacitor and to the negative pressure gas collection device.

6. The method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: The mass ratio of fly ash to quartz sand, kaolin, and iron ore is 45-60%, 20-30%, 20-30%, and 8-10%, respectively.

7. The method for generating thermal insulation material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: The collected domestic waste combustion fly ash is ground in a ball mill and then passed through a 200-mesh sieve (8). The fly ash is then ground again with quartz sand, kaolin, and iron ore and passed through a 250-mesh sieve (8).

8. The method for generating thermal insulation cotton material from municipal solid waste fly ash by Joule heating according to claim 1, characterized in that: The fly ash is laid on the graphite plate (16) with a thickness of 2-4 mm, and the fly ash mixed with quartz sand, kaolin and iron ore is laid on the graphite plate (16) with a thickness of 1-3 mm.

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