A rotary pusher furnace apparatus for fly ash low temperature pyrolysis

Abstract

The utility model relates to solid waste resourceful treatment technical field discloses a kind of rotary propelling furnace equipment for fly ash low-temperature pyrolysis, including furnace body and the rotating shaft in furnace, rotating shaft is equipped with several groups of stirring assembly. Each group of stirring assembly includes rake arm fixed on rotating shaft and rake tooth slidably connected therewith, rake tooth is made of connecting portion and tail scraper. Rake tooth can slide relative to rake arm under the action of gravity, so that scraper moves closely to furnace inner wall when rotating to lower half of furnace body. The structure uses gravity self-adaptive principle, so that scraper continuously and effectively scrapes off fly ash adhered on furnace wall, fundamentally solves the problem of fly ash sticking wall, hardening leading to heat exchange efficiency of furnace wall decline, ensures the uniformity and stability of pyrolysis process, reduces energy consumption and disposal cost.

Description

Technical Field

[0001] This utility model relates to the field of solid waste resource utilization technology, and in particular to a rotary propeller furnace for low-temperature pyrolysis of fly ash. Background Technology

[0002] Fly ash mainly originates from dust particles carried out by flue gas during municipal solid waste incineration, as well as activated carbon, Ca(OH)2, and other substances added during flue gas treatment. Its composition is complex, primarily consisting of a CaO-SiO2-Al2O3 (Fe2O3) system and chloride salts, and it also contains toxic and harmful organic compounds such as dioxins. To achieve safe disposal and resource utilization of fly ash, pollutants such as dioxins must be effectively removed before use. Low-temperature pyrolysis technology, due to its thorough treatment effect and relatively low operating cost, has become one of the most promising fly ash treatment technologies for industrial application.

[0003] However, existing low-temperature pyrolysis equipment has certain limitations in structure and operation, affecting the treatment effect and economy. In some equipment using a screw feeder as the main pyrolysis unit, gaps exist between the screw and the bottom of the furnace shell during processing and assembly, causing fly ash particles to easily accumulate and caking. This severely hinders heat transfer from the furnace wall to the material, reducing pyrolysis efficiency, increasing slag removal and maintenance costs, and raising the overall treatment cost. Therefore, there is an urgent need to develop a low-temperature fly ash pyrolysis device that can effectively prevent material adhesion and caking. Utility Model Content

[0004] In order to solve at least some of the problems existing in the prior art, this utility model provides a rotary propeller furnace device for low-temperature pyrolysis of fly ash that can effectively prevent fly ash from sticking to the wall.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a rotary propulsion furnace for low-temperature pyrolysis of fly ash, comprising a furnace body and a rotating shaft coaxially disposed inside the furnace body, wherein a plurality of stirring components are spaced apart on the rotating shaft; each stirring component comprises: a rake arm, at least one of which is fixedly connected to the rotating shaft; and rake teeth, corresponding one-to-one with the rake arm, wherein each rake tooth is composed of a connecting part and a scraper located at the tail of the connecting part, wherein the connecting part is slidably connected to the rake arm; the rake teeth slide relative to the connecting part under the action of gravity, so that the scraper and the lower part of the inner wall of the furnace body remain in contact.

[0006] Preferably, the contact area between the scraper and the inner wall of the furnace is provided with an arc-shaped surface adapted to the inner wall of the furnace. The arc-shaped surface increases the contact area between the scraper and the arc-shaped inner wall of the furnace, making the scraping action more closely and smoothly, and the wall cleaning effect more thorough.

[0007] Preferably, the scrapers in two adjacent sets of stirring components are defined as the first scraper and the second scraper, and the sweeping range of the first scraper and the second scraper in the circumferential direction of the furnace body at least partially overlaps to achieve continuous coverage of the inner wall of the furnace body.

[0008] Preferably, the furnace body is arranged horizontally, and a discharge port is provided at the bottom of one side of the furnace body; the length direction of each scraper is at a set angle with the axis of the rotating shaft, so as to push the material in the furnace body to the discharge port through several sets of scrapers.

[0009] Preferably, the rake arm consists of a rod, an upper housing, and a lower housing. The rod is fixedly connected to the rotating shaft, and the lower housing is integrally formed on the free end of the rod. The upper housing is detachably mounted on the lower housing and forms a columnar cavity with the lower housing. The outer ends of the upper and lower housings also have slots for connecting to the cavity. The connecting part of the rake teeth passes through the slots and is slidably connected to the cavity.

[0010] Preferably, the connecting portion is provided with a limiting protrusion located inside the cavity to restrict the connecting portion from axially disengaging from the cavity.

[0011] Preferably, the upper housing and / or lower housing are provided with a limiting hole communicating with the slot, and the outer wall of the connecting part is provided with a limiting rib along its axial direction; the limiting rib is slidably connected in the limiting hole to restrict the circumferential rotation between the connecting part and the rake arm.

[0012] Preferably, a dust cover is installed on both sides of the furnace body, and at least part of both sides of the rotating shaft passes through the furnace body and is rotatably connected to the two dust covers respectively.

[0013] Preferably, the furnace body is also equipped with a bracket, on which a rotary drive source is fixedly mounted. The output end of the rotary drive source is coaxially and fixedly connected to the rotating shaft so as to drive the rotating shaft to rotate.

[0014] Preferably, a feed inlet is provided on the top side of one side of the furnace body, and the feed inlet and the discharge outlet are located at two opposite ends of the furnace body, respectively.

[0015] Therefore, this utility model has the following beneficial effects: The rake teeth and rake arms are slidably connected, allowing the scraper to automatically slide downwards under its own gravity when it reaches the lower half of the furnace body during the rotation of the stirring assembly, thus moving closely against the inner wall of the furnace. This gravity-adaptive design can continuously scrape off fly ash adhering to the furnace wall, effectively solving the problem of fly ash sticking and caking due to high temperature and stickiness, ensuring the cleanliness and heat transfer efficiency of the furnace body's inter-wall heat exchange surface. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model. Figure 2 This is a three-dimensional structural cross-sectional view of the present invention. Figure 3 for Figure 2 Enlarged view of the local structure at point A in the middle. Figure 4 This is a schematic diagram of the three-dimensional structure inside the furnace. Figure 5 This is a three-dimensional structural diagram of the rake arm and rake teeth. Figure 6 Exploded view of the rake arm and rake teeth; Figure 7 This is a schematic diagram of the heating module and furnace body of this utility model.

[0017] Figure 8 This is a schematic diagram of the flue gas flow in the side view of this utility model.

[0018] In the diagram: Furnace body 1, discharge port 11, dust cover 12, support 13, rotary drive source 14, feed port 15, heating module 16, combustion chamber 161, flue gas guiding structure 17, flue gas chamber 171, exhaust port 172; rotating shaft 2; stirring assembly 3; rake arm 31, rod 311, upper shell 312, lower shell 313, chamber 314, slot 315, limiting hole 316; rake teeth 32, connecting part 321, limiting protrusion 3211, limiting rib 3212, scraper 322, arc surface 3221. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions and the beneficial technical effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments.

[0020] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this utility model; in this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of indicated technical features. Features specified with "first" or "second" may explicitly or implicitly indicate that at least one of those features is included.

[0021] like Figures 1 to 8 The rotary propeller furnace device shown includes a transversely arranged furnace body 1 and a rotating shaft 2 coaxially arranged inside the furnace body 1. Several sets of stirring components 3 are distributed at intervals on the rotating shaft 2. Figure 2 and Figure 3As shown, each stirring assembly 3 includes a rake arm 31 fixedly connected to the rotating shaft 2, and rake teeth 32 slidably connected to the rake arm 31. The rake teeth 32 consist of a connecting part 321 and a scraper 322 located at the tail of the connecting part 321. In this structure, when the rotating shaft 2 drives the stirring assembly 3 to rotate, the connecting part 321 of the rake teeth 32 can slide inside the rake arm 31. Under the action of gravity, when the scraper 322 rotates to the lower half of the furnace body 1, the rake teeth 32 will automatically slide down, so that the scraper 322 slides tightly against the inner wall of the furnace body 1; when the scraper 322 rotates to the upper half, the rake teeth 32 retract relative to the rake arm to avoid rigid interference with the furnace wall. At the same time, through this gravity adaptive design, the scraper 322 intermittently and relatively gently scrapes off the fly ash adhering to the hot wall (i.e., the inner wall of the furnace body), fundamentally solving the core problem of fly ash easily sticking to the wall and caking in traditional equipment, and reducing the energy consumption and maintenance frequency of disposal.

[0022] In some practical applications, such as Figure 3 and Figure 5 As shown, the contact area between the scraper 322 and the inner wall of the furnace body 1 is provided with an arc-shaped surface 3221 that is adapted to the inner wall of the furnace body 1. In this structure, the arc-shaped surface 3221 ensures that the scraper 322 has surface contact with the inner wall of the cylindrical furnace body, rather than point contact, which significantly increases the effective cleaning area and fit, making the scraping cleaner and more stable.

[0023] Specifically, as shown in Figure 4, the scrapers 322 in two adjacent sets of stirring components 3 are defined as the first scraper 322 and the second scraper 322, respectively. The sweeping range of the first scraper 322 and the second scraper 322 in the circumferential direction of the furnace body 1 at least partially overlaps. In this structure, the multiple sets of stirring components 3 distributed along the axial direction of the rotating shaft 2 have scrapers 322 forming continuous or staggered cleaning areas in the circumferential direction, ensuring that every area of ​​the bottom inner wall of the furnace body 1 can be cleaned by at least one scraper 322 within the rotation cycle, achieving coverage without dead angles.

[0024] Specifically, such as Figure 2 As shown, a discharge port 11 is provided at the bottom of one side of the furnace body 1, and the length direction of each scraper 322 is at a set angle to the axis of the rotating shaft 2. In this structure, the angled scrapers 322, while revolving around the rotating shaft 2 to stir and clean the walls, generate an axial component force on the material, pushing the material to move slowly along the axis of the furnace body 1; at the same time, through the synergistic action of multiple sets of stirring components 3, the material is continuously and smoothly pushed from the feed end to the discharge port 11, realizing the continuity of the pyrolysis process, avoiding excessively long or short local residence time of the material, and improving the uniformity of pyrolysis and the processing efficiency of the equipment. In some embodiments, the set angle can be designed according to the material characteristics and the required residence time, for example, it can be 30° to 60°.

[0025] like Figure 2As shown, a feed inlet 15 is provided on the top of one side of the furnace body 1, and the feed inlet 15 and the discharge outlet 11 are located on two opposite sides of the furnace body 1. The material is added from the top feed inlet 15 and discharged from the bottom discharge outlet 11; by cooperating with the scraper 322 with axial thrust, a unidirectional material flow path is formed, which is beneficial to controlling the pyrolysis residence time of the material in the furnace, ensuring that pollutants such as dioxins in the fly ash are fully decomposed, and optimizing the pyrolysis process effect.

[0026] In some practical applications, such as Figures 4 to 6 As shown, the rake arm 31 consists of a rod 311, an upper housing 312, and a lower housing 313. The rod 311 is fixedly connected to the rotating shaft 2. The lower housing 313 is integrally formed on the free end of the rod 311. The upper housing 312 is detachably mounted on the lower housing 313, forming a cylindrical chamber 314 with the lower housing 313. The outer ends of the upper housing 312 and the lower housing 313 also have slots 315 for connecting the chamber 314. The connecting part 321 of the rake teeth 32 passes through the slots 315 and is slidably connected to the chamber 314. The separate upper housing 312 and lower housing 313 facilitate the machining of the internal chamber 314 and slots 315, and after assembly, they form a complete sliding chamber 314. The detachable upper housing 312 makes the installation, maintenance, or replacement of the rake teeth 32 extremely convenient, without the need to disassemble the entire rake arm 31 or the rotating shaft 2, reducing maintenance difficulty and time costs.

[0027] Specifically, such as Figure 6 As shown, a limiting protrusion 3211 is provided on the connecting part 321, and the limiting protrusion 3211 is located inside the chamber 314. In this structure, the size of the limiting protrusion 3211 is larger than the width of the slot 315, so that the connecting part 321 can slide freely along its axial direction within the chamber 314, but cannot be completely dislodged from the slot 315, effectively preventing the risk of the rake teeth 32 accidentally falling off during equipment operation or maintenance.

[0028] Specifically, such as Figure 6 As shown, the upper shell 312 and / or the lower shell 313 are provided with limiting holes 316, and the outer wall of the connecting part 321 is provided with limiting ribs 3212 along its axial direction; the limiting ribs 3212 are slidably connected in the limiting holes 316. The limiting ribs 3212 and the limiting holes 316 form a sliding pair, which restricts the rake teeth 32 from rotating around their own axis during sliding; at the same time, through this circumferential limiting, it is ensured that no matter where the rake teeth 32 is in the sliding stroke, the scraper 322 at its tail (especially the arc surface 3221) can always maintain the preset optimal working angle to fit against the inner wall of the furnace, ensuring its cleaning effect on the inner wall of the furnace.

[0029] In some practical applications, such as Figure 1 and Figure 2As shown, a dust cover 12 is installed on both sides of the furnace body 1. At least part of both sides of the rotating shaft 2 passes through the furnace body 1 and is rotatably connected to the two dust covers 12 respectively, that is, the rotating shaft 2 is rotatably connected through bearings. The dust cover 12 forms a relatively closed space, covering the dynamic seal between the rotating shaft 2 and the side end of the furnace body 1; at the same time, through this design, dust that may escape from the furnace is isolated to a certain extent, improving the workshop working environment.

[0030] A bracket 13 is installed on the furnace body 1, and a rotary drive source 14 is fixedly installed on the bracket 13. The output end of the rotary drive source 14 is coaxially and fixedly connected to the rotating shaft 2. The bracket 13 provides a stable installation base for the rotary drive source 14. The power is directly transmitted to the rotating shaft 2 through components such as couplings. The rotary drive source is generally a rotary motor.

[0031] In some practical applications, because some vertical furnaces use direct contact heating, that is, fly ash comes into direct contact with hot flue gas, the oxygen content in the furnace is not easy to control precisely, which may affect the thermal decomposition efficiency of dioxins, or even cause fly ash sintering or the generation of new pollutants.

[0032] In this embodiment, as Figures 7 to 8 As shown, the furnace body 1 has a heating module 16 and a flue gas guiding structure 17. The flue gas guiding structure 17 surrounds the heating module 16 and the outer peripheral surface of the furnace body 1, forming a flue gas chamber 171 between the structure and the outer peripheral surface of the furnace body 1. The flue gas guiding structure 17 also has a flue gas outlet 172. In some embodiments, the heating module 16 is a combustion chamber 161. In this structure, the combustion chamber 161 converts chemical energy into heat energy through fuel outside the furnace body. The generated high-temperature flue gas is introduced into the flue gas chamber 171. The high-temperature flue gas surrounds the entire outer wall of the furnace body 1 for heating. The heat is indirectly transferred to the fly ash material inside the furnace body through the furnace body wall. This is a typical indirect heat exchange. At the same time, through this external heating method, the material inside the furnace is in an oxygen-deficient or oxygen-free pyrolysis atmosphere, avoiding sintering or combustion caused by fly ash contacting open flames or excessive oxygen. This ensures the stability, controllability, and safety of the low-temperature pyrolysis process. The flue gas is finally discharged from the flue gas outlet 172 and enters the subsequent processing system. In some embodiments, the number and power of the combustion chambers 161 can be flexibly configured according to the size of the furnace body 1 and the heat load requirements.

[0033] Referring to the accompanying drawings, the working principle of this utility model is as follows: Fly ash material is continuously fed into the horizontally arranged furnace body 1 through the feed inlet 15. An external rotary drive source 14 drives multiple sets of stirring components 3 to rotate at a constant speed via a rotating shaft 2. The scraper 322 in the stirring component 3, being at a certain angle to the rotating shaft 2, continuously flips and pushes the material slowly towards the discharge port 11 during rotation. When the scraper 322 rotates to the lower half of the furnace body 1, the rake teeth 32 slide down along the rake arm 31 under the action of gravity, causing the scraper 322 to closely adhere to and scrape the inner wall of the furnace body, preventing fly ash adhesion. At the same time, the high-temperature flue gas generated in the combustion chamber 161 flows in the flue gas chamber 171 (e.g., Figure 8 As indicated by the arrow in the diagram, the fly ash moving inside the furnace is uniformly and stably heated indirectly through the furnace wall, causing it to undergo low-temperature pyrolysis in an oxygen-deficient environment, effectively decomposing organic matter such as dioxins. The treated fly ash is finally discharged from discharge port 11. Therefore, the entire equipment, through the synergy of a gravity-adaptive scraping wall structure and an indirect heating system, achieves continuous, efficient, and low-consumption pyrolysis of fly ash, fundamentally solving the problem of heat transfer deterioration caused by wall adhesion.

[0034] It should be noted that the furnace body also has a nitrogen port (not shown in the figure). Nitrogen is used as a protective atmosphere and is introduced through the nitrogen port. A regulating valve is installed in front of the nitrogen port to regulate the amount of nitrogen entering the furnace. An oxygen content detector is installed in the furnace body to detect the oxygen content inside the furnace, which is used as a condition for the low-temperature pyrolysis treatment of fly ash, and the oxygen content inside the furnace is controlled to be less than 1%.

[0035] The temperature inside the furnace is controlled between 300 and 500°C. The combustion chamber is equipped with a temperature monitoring instrument to monitor the temperature inside the furnace. The temperature monitoring instrument is interlocked with the burner, and the burner can automatically adjust according to the temperature changes inside the furnace to achieve precise temperature control.

[0036] In the description of this utility model, it should be understood that the directions or positional relationships indicated by up, down, left, right, top, bottom, inner side, outer side, etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the purpose of more clearly describing the technical solution of this utility model, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as a limitation of this utility model.

[0037] Although specific embodiments of the present invention are described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the present invention. Various substitutions, alterations, and modifications may be conceived without departing from the spirit and scope of the present invention.

Claims

1. A rotary propeller furnace for low-temperature pyrolysis of fly ash, characterized in that, The furnace includes a furnace body (1) and a rotating shaft (2) coaxially disposed inside the furnace body (1). Several sets of stirring components (3) are distributed at intervals on the rotating shaft (2). Each set of stirring components (3) includes: The rake arm (31) is equipped with at least one and is fixedly connected to the rotating shaft (2); The rake teeth (32) correspond one-to-one with the rake arm (31), and the rake teeth (32) are composed of a connecting part (321) and a scraper (322) located at the tail of the connecting part (321). The connecting part (321) is slidably connected to the rake arm (31). The rake teeth (32) slide relative to the connecting part (321) under the action of gravity, so that the scraper (322) abuts against the inner wall of the furnace body (1).

2. The rotary propeller furnace equipment for low-temperature pyrolysis of fly ash according to claim 1, characterized in that, The contact area between the scraper (322) and the inner wall of the furnace body (1) is provided with an arc-shaped surface (3221) that is adapted to the inner wall of the furnace body (1).

3. The rotary propeller furnace equipment for low-temperature pyrolysis of fly ash according to claim 1, characterized in that: The scrapers (322) in two adjacent stirring components (3) are defined as the first scraper (322) and the second scraper (322), respectively. The sweeping range of the first scraper (322) and the second scraper (322) in the circumferential direction of the furnace body (1) overlaps at least partially to achieve continuous coverage of the inner wall of the furnace body (1).

4. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 1 or 3, characterized in that, The furnace body (1) is arranged horizontally, and a discharge port (11) is provided on the bottom of one side of the furnace body (1); the length direction of each scraper (322) is at a set angle with the axis of the rotating shaft (2) so as to push the material in the furnace body (1) towards the discharge port (11) through several sets of scrapers (322).

5. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 1, characterized in that, The rake arm (31) is composed of a rod (311), an upper shell (312) and a lower shell (313). The rod (311) is fixedly connected to the rotating shaft (2). The lower shell (313) is integrally formed on the free end of the rod (311). The lower shell (313) is detachably installed on the lower shell (313) and forms a columnar cavity (314) with the lower shell (313). The outer ends of the upper shell (312) and the upper shell (312) also have slots (315) for connecting the cavity (314). The connecting part (321) of the rake teeth (32) passes through the slot (315) and is slidably connected to the cavity (314).

6. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 5, characterized in that, The connecting part (321) is provided with a limiting protrusion (3211), which is located in the chamber (314) to restrict the connecting part (321) from axially disengaging from the chamber (314).

7. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 5, characterized in that, The upper housing (312) and / or the lower housing (313) are provided with a limiting hole (316) communicating with the slot (315), and a limiting rib (3212) is provided on the outer wall of the connecting part (321) along its axial direction; the limiting rib (3212) is slidably connected in the limiting hole (316) to restrict the circumferential rotation between the connecting part (321) and the rake arm (31).

8. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 1, characterized in that, A dust cover (12) is installed on both sides of the furnace body (1). At least part of the two sides of the rotating shaft (2) pass through the furnace body (1) and are rotatably connected to the two dust covers (12).

9. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 4, characterized in that, A feed inlet (15) is also provided on the top of one side of the furnace body (1), and the feed inlet (15) and the discharge outlet (11) are located at the two opposite ends of the furnace body (1).

10. A rotary propeller furnace for low-temperature pyrolysis of fly ash according to claim 1, characterized in that, The furnace body (1) has a heating module (16) and a flue gas guiding structure (17); the flue gas guiding structure (17) at least partially covers the heating module (16) and the outer periphery of the furnace body (1) and forms a flue gas cavity (171) between the heating module (16) and the outer periphery of the furnace body (1), and the flue gas guiding structure (17) also has a flue gas outlet (172).

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