A waste treatment system and a method of treating waste

Abstract

The present application relates to a kind of garbage processing system and processing method, including work platform, erecting on work platform's rotary kiln and the air extractor and heating device of the end of rotary kiln in two rows: one end of rotary kiln is inclined and set down and with heating device same side, to make heating device heat supply to rotary kiln inside;Rotary kiln is sleeved with several guide rings, and the inner diameter of several guide rings gradually increases along the direction of heating device;Several guide rings are connected with smoke cover, to reduce the radial diffusion degree of flame in heating device;Air extractor is communicated with the other end of rotary kiln, to pull the flame length of heating device.The combination design of smoke cover, air extractor and guide ring makes that fly ash is under the more uniform and lengthened flame temperature and carries out sufficient reaction, and heat loss is lower.

Description

Technical Field

[0001] This invention relates to the field of waste treatment technology, and in particular to a waste treatment system and method. Background Technology

[0002] Municipal solid waste generates a large amount of fly ash during incineration for power generation, and this fly ash contains numerous hazardous substances (such as benzo[a]pyrene, benz[a]anthracene, dioxins, and other organic pollutants). The specific operational method for co-processing fly ash in cement kilns involves first extracting potassium, sodium, sulfur, and chlorine from the fly ash using water washing to produce industrial products. The remaining portion is then sent to a cement rotary kiln for high-temperature calcination. The high temperature of the cement rotary kiln solidifies and decomposes heavy metals and dioxins, not only safely and effectively disposing of the fly ash but also helping to conserve land resources for fly ash landfills.

[0003] Chinese invention patent CN112044924B discloses a system for large-scale disposal of fly ash using a cement kiln. This system involves installing a first burner inside a cement rotary kiln and injecting flames into the kiln to thermally desorb the fly ash that moves to the vicinity of the burner. The heated fly ash volatilizes from the fly ash and is then treated by a waste gas treatment device connected to the flue gas chamber. Finally, the fly ash is sent to a detoxification fly ash treatment device, where a low-temperature thermal decomposition reaction is used to remove soluble chloride salts at a temperature below 500°C, thereby completing the dechlorination and detoxification process of dioxins.

[0004] However, in actual use, the fly ash is transported to the cement rotary kiln via the smoke chamber and moves towards the kiln head under the combined action of the kiln's rotation and the fly ash's own gravity (the first burner is located on one side of the kiln head with the flame jet pointing towards the direction the fly ash enters). To ensure the temperature of the fly ash radiated to the kiln head by the flame is between 500℃ and 800℃, the flame temperature of the first burner must be maintained above 1000℃. However, due to the limited flame jet length of the first burner, the temperature inside the kiln is not uniform enough. This prevents the end of the rotary kiln near the smoke chamber from achieving sufficient low-temperature thermal desorption of the fly ash, further wasting and losing heat energy during the transfer process towards the end near the smoke chamber. Summary of the Invention

[0005] In view of this, it is necessary to provide a waste treatment system and method to solve the technical problems of large heat loss and insufficient low-temperature thermal desorption in the prior art.

[0006] This invention provides a waste treatment system, including a working platform, a rotary kiln mounted on the working platform, and exhaust fans and heating devices arranged at both ends of the rotary kiln.

[0007] One end of the rotary kiln is inclined downward and is on the same side as the heating device, so that the heating device can supply heat to the rotary kiln.

[0008] The rotary kiln is fitted with several guide rings, and the inner diameter of the guide rings increases progressively along the direction of the heating device.

[0009] Several of the guide rings are connected to smoke hoods to reduce the radial spread of the flame in the heating device;

[0010] The exhaust fan is connected to the other end of the rotary kiln and is used to extend the flame length of the heating device.

[0011] In one embodiment of the present invention, a rotating disk is rotatably connected to the other end of the rotary kiln, and an ash feeding device, an exhaust fan, and a waste gas treatment device are connected to the outside of the rotating disk. The exhaust port of the exhaust fan extends into the rotary kiln through the rotating disk and points into the smoke collection hood.

[0012] In one embodiment of the present invention, the inner diameter of the guide ring is tapered, and the narrow openings are all located on the side away from the heating device.

[0013] In one embodiment of the present invention, the narrow opening of the guide ring is provided with rounded corners.

[0014] In one embodiment of the present invention, the smoke hood includes a hood body, the outer wall of the hood body is provided with ventilation holes, and the outer wall of the hood body is also connected with a crossbar, so that one side of the crossbar is fixedly connected to the inner wall of the guide ring.

[0015] In one embodiment of the present invention, the vents are arranged in groups, with each group evenly distributed along the axial direction of the cover, and different groups evenly distributed along the circumferential direction of the cover.

[0016] In one embodiment of the present invention, refractory bricks are fixedly connected to the inner wall of the rotary kiln, and the refractory bricks are located between the rotary kiln and the guide ring.

[0017] In one embodiment of the present invention, the refractory brick has at least two holes.

[0018] The present invention also provides a method for treating waste in a waste treatment system, applicable to the aforementioned waste treatment system, comprising the following steps:

[0019] 1) Preheating the kiln head: The heating device injects flames into the rotary kiln for preheating;

[0020] 2) Flame elongation: The exhaust fan draws air into the rotary kiln to elongate the flame of the heating device;

[0021] 3) Fly ash feeding: Fly ash is conveyed to the bottom of the other end of the rotary kiln via the ash feeding device;

[0022] 4) Waste gas recovery and treatment: After low-temperature thermal adsorption, the organic pollutants such as dioxins in fly ash are adsorbed and treated by the waste gas treatment device.

[0023] Preferably, the preheating time of the heating device is at least ten minutes.

[0024] Compared with the prior art, the waste treatment system and method provided by the present invention have the following beneficial effects:

[0025] In this invention, by installing several guide rings inside the rotary kiln and connecting a smoke hood inside the guide rings, the lateral diffusion of the flame in the heating device can be effectively reduced, and the flame can become more uniform and stable. This allows heat to diffuse more evenly along the axial direction radially into the rotary kiln. Furthermore, by installing an exhaust fan, the flame of the heating device is elongated, allowing heat to be radiated more evenly to all parts of the rotary kiln in a timely manner, effectively reducing heat loss and the time required for radiation. In addition, the inner diameter of the guide rings gradually increases along the direction of the heating device, so that as the fly ash moves along the inner wall of the guide rings towards the heating device, the distance from the flame of the heating device gradually increases, further preventing heat rise caused by proximity to the flame source. This makes the temperature more uniform along the axial direction in the rotary kiln, providing more time for low-temperature thermal desorption of fly ash and achieving better decomposition reaction results. Moreover, it eliminates the need for high-temperature radiation from the heating device to meet the separation requirements of dioxins and other organic pollutants in fly ash, reducing heat loss.

[0026] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail in the following embodiments and their accompanying drawings. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0028] Figure 1 is an isometric view of a waste treatment system provided by the present invention;

[0029] Figure 2 for Figure 1 Isometric drawing of a section of a rotary kiln;

[0030] Figure 3 for Figure 1 Schematic diagram of the connection relationship between the rotary kiln (partial view) and the guide ring;

[0031] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0032] Figure 5 for Figure 3 Enlarged view of point B in the middle;

[0033] Figure 6 for Figure 1 A schematic diagram showing the connection between the rotary kiln (partial view), the guide ring, and the smoke hood;

[0034] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0035] Figure 8 for Figure 6 Isometric drawing of a partial view of the central smoke hood;

[0036] Figure 9 for Figure 6 Isometric drawing of the guide ring;

[0037] Figure 10 for Figure 6 Top view of the guide ring;

[0038] Figure 11 for Figure 6 Bottom view of the guide ring;

[0039] Figure 12 A partial cross-sectional view of the reaction inside a rotary kiln in an embodiment of a waste treatment system provided by the present invention;

[0040] Figure 13 for Figure 12 Enlarged diagram of point D in the middle.

[0041] The attached figures are labeled as follows:

[0042] 100. Working platform; 200. Rotary kiln; 210. Rotating disc; 220. Air inlet; 230. Refractory brick; 231. Hole; 240. Through hole; 300. Exhaust fan; 310. Exhaust vent; 400. Heating device; 500. Guide ring; 510. Rounded corner; 600. Smoke hood; 610. Hood body; 620. Vent hole; 630. Crossbar; 700. Ash inlet device; 800. Waste gas treatment device; 810. Gas collection pipe; 900. Drive system. Detailed Implementation

[0043] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0044] Please see Figures 1-13 This invention provides a waste treatment system, including a working platform 100, a rotary kiln 200 mounted on the working platform 100, and exhaust fans 300 and heating devices 400 arranged at both ends of the rotary kiln 200. One end of the rotary kiln 200 is inclined downward and on the same side as the heating device 400, so that the heating device 400 supplies heat to the rotary kiln 200. A plurality of guide rings 500 are fitted inside the rotary kiln 200, and the inner diameter of the plurality of guide rings 500 increases progressively along the direction of the heating device 400. A smoke hood 600 is connected inside the plurality of guide rings 500 to reduce the radial diffusion of the flame in the heating device 400. The exhaust fans 300 are connected to the other end of the rotary kiln 200 to draw the flame length of the heating device 400.

[0045] In the above-mentioned processing system, the heating device 400 is first started to preheat the rotary kiln 200. The flame of the heating device 400 is sprayed towards the other end of the rotary kiln 200. Then, the fly ash is transferred from the other end of the rotary kiln 200 (i.e., the inclined upward end) into the rotary kiln 200, and the rotary kiln 200 is started to rotate (a drive system 900 is provided on one side of the rotary kiln 200, which preferably uses a DC motor and a DC speed controller, and drives the rotation of the rotary kiln 200 through a gear set on the outer wall of the rotary kiln 200). When the fly ash enters the rotary kiln 200 and moves along the inner wall of the guide ring 500 towards the side closer to the heating device 400 under the rotation of the rotary kiln 200. Because the smoke hood 600 concentrates the flame generated by the heating device 400, the radial diffusion of the flame is reduced. Furthermore, the exhaust fan 300 at the other end of the rotary kiln 200 pulls the flame length, allowing the heat generated by the flame to diffuse more evenly along the axial direction. This not only enables the fly ash to undergo low-temperature thermal desorption reaction immediately upon entering the rotary kiln 200, but also effectively reduces heat loss and waste caused by heat diffusion from the heating device 400 to the side away from the rotary kiln 200. In addition, because the inner diameter of the guide ring 500 gradually increases along the direction of the heating device 400, the straight-line distance between the fly ash and the flame source gradually increases as the fly ash approaches the heating device 400. This effectively avoids the temperature rise caused by approaching the flame source, further optimizing the temperature environment for low-temperature thermal desorption of fly ash and providing better conditions for the fly ash to react fully.

[0046] To ensure that the rotation of the rotary kiln 200 does not affect the transmission of fly ash at the starting end, in one embodiment of the present invention, a rotating disk 210 is rotatably connected to the other end of the rotary kiln 200 (specifically, the outer wall of the rotating disk 210 is rotatably connected to the inner diameter of the rotary kiln 200, and the rotating disk 210 is provided with several through holes 240 for expanding and connecting other devices. Preferably, a limiting groove can be provided in the rotary kiln 200, and the rotating disk 210 can be placed in it, which can both achieve the rotatable connection and prevent the rotating disk 210 from falling off). An ash feeding device 700, an exhaust fan 300, and a waste gas treatment device 800 are connected to the outside of the rotating disk 210 (preferably, they are connected through the aforementioned through holes 240), and the exhaust port 310 of the exhaust fan 300 extends into the rotary kiln 200 through the rotating disk 210 and points into the smoke collection hood 600. It should be noted that the heating device 400 includes a pulverized coal silo, support frame, blower, pulverized coal injection pipe, and pulverized coal nozzle. It injects pulverized coal and air into the pulverized coal nozzle via the blower and pulverized coal injection pipe, and heats the rotary kiln 200 through the burner. Its specific working principle and structural composition can be referenced from cement rotary kilns, and due to existing technology, will not be elaborated upon. The waste gas treatment device 800 and the ash inlet device 700 are also existing technologies. Their working principles are respectively to thoroughly decompose organic pollutants such as dioxins and their decomposition products using a higher temperature (1200℃) (the waste gas treatment device 800 is equipped with a gas collection pipe 810 extending into the upper part of the rotary kiln 200, and a built-in exhaust fan sucks in harmful substances), to remove toxic substances, and to send fly ash into the rotary kiln 200 through a silo and transmission pipeline.

[0047] In order to improve the efficiency of fly ash treatment, in one embodiment of the present invention, the inner diameter of the guide ring 500 is tapered, and the narrow opening is located on the side away from the heating device 400. This allows the fly ash to move more smoothly along the inner wall of the guide ring 500 toward the side of the heating device 400.

[0048] Furthermore, in one embodiment of the present invention, the narrow opening of the guide ring 500 is provided with a rounded corner 510, which can effectively prevent the retention of a small amount of fly ash. Preferably, the rotary kiln 200 can be provided with an openable and closable feed port on the side near the heating device 400 to further treat the fly ash residue after the reaction is completed in a harmless manner.

[0049] In order to enable the flame to burn more fully, in one embodiment of the present invention, the smoke hood 600 includes a hood body 610, the outer wall of the hood body 610 is provided with a ventilation hole 620, and the outer wall of the hood body 610 is also connected with a crossbar 630, so that one side of the crossbar 630 is fixedly connected to the inner wall of the guide ring 500, so that the hood body 610 can be fixed on the rotary kiln 200 by the crossbar 630.

[0050] Furthermore, in one embodiment of the present invention, the vent holes 620 are arranged in groups, with each group evenly distributed along the axial direction of the shroud 610, and different groups evenly distributed along the circumference of the shroud 610. This allows more oxygen to enter the shroud 610 through the vent holes 620, ensuring complete combustion and stability of the flame. It should be noted that the outer wall of the rotary kiln 200 is also provided with an air inlet 220, and a one-way air inlet valve is installed inside the air inlet 220, effectively ensuring a sufficient oxygen supply throughout the rotary kiln 200.

[0051] In order to increase the service life of the rotary kiln 200, in one embodiment of the present invention, the inner wall of the rotary kiln 200 is fixedly connected with refractory bricks 230, and the refractory bricks 230 are located between the rotary kiln 200 and the guide ring 500.

[0052] Furthermore, in one embodiment of the present invention, the refractory brick 230 has at least two holes 231, which enables the lightweight design of the refractory brick 230 and the rotary kiln 200.

[0053] This invention also provides a waste treatment method for a waste treatment system, applicable to a waste treatment system, comprising the following steps:

[0054] 1) Preheating the kiln head: The heating device 400 injects flames into the rotary kiln 200 for preheating;

[0055] 2) Flame elongation: The exhaust fan 300 draws air into the rotary kiln 200 to elongate the flame of the heating device 400.

[0056] 3) Fly ash feeding: Fly ash is fed into the bottom of the other end of the rotary kiln 200 via the ash feeding device 700;

[0057] 4) Waste gas recovery and treatment: After low-temperature thermal adsorption, the fly ash contains organic pollutants such as dioxins, which are then adsorbed and treated by the waste gas treatment device 800.

[0058] The processing method provided by this invention is more efficient and helps to save resources. Specifically, by preheating the kiln head, the rotary kiln 200 can reach the initial temperature in a shorter time, thereby providing stable conditions for the heating device 400 to continuously supply heat and for the fly ash to undergo low-temperature thermal adsorption. This method is more energy-efficient than the original method of directly using a flame temperature of over 1000°C.

[0059] By adopting the above-mentioned treatment method and through the process of elongating the flame, the flame can heat more fly ash in the axial direction as early as possible, so that organic pollutants such as dioxins in the fly ash can volatilize more quickly and fully and be captured by the waste gas treatment device 800.

[0060] Using the above processing method, preferably, the preheating time of the heating device 400 is at least ten minutes. This ensures that the initial temperature inside the rotary kiln 200 is not too low, provides conditions for the subsequent heating device 400 to heat up quickly, and avoids the situation where the temperature rise inside the rotary kiln 200 is ineffective due to too short a preheating time.

[0061] In the specific operation of the aforementioned waste treatment system and method, the rotary kiln 200 is first preheated for at least ten minutes by the heating device 400. Then, the fly ash is fed into the other end of the rotary kiln 200 by the ash feeding device 700. The rotary kiln 200 rotates under the drive system 900, moving the fly ash towards one side of the heating device 400. Because the smoke hood 600 gathers the flame in the heating device 400, reducing the degree of lateral flame diffusion, and the exhaust fan 300 stretches the flame, the flame can heat the fly ash earlier and the temperature is more uniform. The heat loss during the diffusion to the other end of the rotary kiln 200 is also relatively small.

[0062] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A waste treatment system, characterized in that, Includes a working platform, a rotary kiln mounted on the working platform, and exhaust fans and heating devices arranged at both ends of the rotary kiln: One end of the rotary kiln is inclined downward and is on the same side as the heating device, so that the heating device can supply heat to the rotary kiln. The rotary kiln is fitted with several guide rings, and the inner diameter of the guide rings increases progressively along the direction of the heating device. Several of the guide rings are connected to smoke hoods to reduce the radial spread of the flame in the heating device; The exhaust fan is connected to the other end of the rotary kiln and is used to extend the flame length of the heating device.

2. The waste treatment system according to claim 1, characterized in that, The rotary kiln is rotatably connected to a rotating disc at the other end. An ash inlet device, an exhaust fan, and a waste gas treatment device are connected to the outside of the rotating disc. The exhaust port of the exhaust fan extends into the rotary kiln through the rotating disc and points towards the smoke collection hood.

3. The waste treatment system according to claim 1, characterized in that, The inner diameter of the guide ring is tapered, and the narrow openings are all located on the side away from the heating device.

4. A waste treatment system according to claim 3, characterized in that, The narrow opening of the guide ring is provided with rounded corners.

5. A waste treatment system according to claim 1, characterized in that, The smoke hood includes a hood body, the outer wall of which has ventilation holes, and the outer wall of the hood body is also connected to a crossbar, so that one side of the crossbar is fixedly connected to the inner wall of the guide ring.

6. A waste treatment system according to claim 5, characterized in that, The ventilation holes are arranged in groups, with each group evenly distributed along the axial direction of the cover, and different groups evenly distributed along the circumference of the cover.

7. A waste treatment system according to claim 6, characterized in that, The inner wall of the rotary kiln is fixedly connected with refractory bricks, and the refractory bricks are located between the rotary kiln and the guide ring.

8. A waste treatment system according to claim 7, characterized in that, The refractory brick has at least two holes.

9. A method for treating waste in a waste treatment system, applicable to the waste treatment system as described in any one of claims 1-8, characterized in that, Includes the following steps: 1) Preheating the kiln head: The heating device injects flames into the rotary kiln for preheating; 2) Flame elongation: The exhaust fan draws air into the rotary kiln to elongate the flame of the heating device; 3) Fly ash feeding: Fly ash is conveyed to the bottom of the other end of the rotary kiln via the ash feeding device; 4) Waste gas recovery and treatment: After low-temperature thermal adsorption, the organic pollutants in fly ash are adsorbed and treated by the waste gas treatment device.

10. The waste treatment method of the waste treatment system according to claim 9, characterized in that, The heating device requires a preheating time of more than ten minutes.

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