An integrated pyrolysis sintering roller kiln for preparing nanobiological soil amendment

Abstract

The utility model relates to ceramic industry kiln technical field, concretely relates to a kind of integrated pyrolysis sintering roller way kiln of preparation nanometer biological soil amendment, including kiln body, the roller way being set in kiln body and the heater being distributed along the length direction of kiln body, kiln body is sequentially provided with preheating zone, sealed pyrolysis zone and high-temperature sintering zone along material conveying direction;Sealed pyrolysis zone includes the refractory cavity built in kiln body, the corresponding section of roller way is wrapped in the refractory cavity, forms a physical partition;The inlet end and outlet end of refractory cavity are provided with atmosphere lock structure, and the inert gas supply pipeline and volatile component discharge pipeline are connected on the refractory cavity;Gas control device is equipped on inert gas supply pipeline, for providing and maintaining inert atmosphere environment in refractory cavity.The utility model can integrally realize ceramic sintering and biomass pyrolysis.

Description

Technical Field

[0001] This utility model relates to the field of ceramic industrial kiln technology, specifically to an integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners. Background Technology

[0002] In the field of agricultural soil improvement, maintaining and enhancing soil fertility is a key challenge. Traditional methods mainly rely on the direct application of chemical fertilizers or organic matter, but these methods suffer from problems such as rapid nutrient release, easy loss, and difficulty in sustaining the improvement effect.

[0003] In recent years, biochar has been used as a soil conditioner to improve water retention and adsorption due to its stable chemical properties and abundant porous structure. However, simply physically mixing biochar with soil has limitations such as uneven distribution, easy migration with water, and limited functionality. On the other hand, porous ceramic materials have the advantage of structural stability as carriers, but they generally lack the ability to provide carbon sources and promote microbial habitat.

[0004] Existing technologies for preparing ceramic-biochar composites mostly employ a stepwise method: first, biomass is independently pyrolyzed to produce biochar, which is then mixed with ceramic raw materials, shaped, and sintered. This process is lengthy, energy-intensive, and results in weak interfacial bonding between the two phases, making it difficult to achieve uniform composite at the microscale, thus limiting the synergistic performance of the materials and their large-scale application.

[0005] Therefore, there is an urgent need in this field for a dedicated device that can integrate ceramic sintering and biomass heating. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide an integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] An integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners includes a kiln body, rollers disposed within the kiln body, and heaters distributed along the length of the kiln body. The kiln body contains a preheating zone, a sealed pyrolysis zone, and a high-temperature sintering zone arranged sequentially along the material conveying direction. The sealed pyrolysis zone includes a refractory material cavity built into the kiln body, which encloses a corresponding section of the rollers, forming a physical barrier. Both the inlet and outlet ends of the refractory material cavity are equipped with atmosphere lock structures. An inert gas supply pipeline and a volatile matter discharge pipeline are connected to the refractory material cavity. A gas control device is installed on the inert gas supply pipeline to provide and maintain an inert atmosphere environment within the refractory material cavity.

[0009] As a further improvement of this utility model, the atmosphere lock structure is an air curtain type seal.

[0010] As a further embodiment of this invention, the gas control device includes a flow control unit connected to the inert gas supply pipeline and an oxygen content sensor disposed in the refractory material cavity, wherein the flow control unit is signal-connected to the oxygen content sensor.

[0011] As a further embodiment of this invention, the refractory material cavity is also equipped with a pressure sensor and a pressure regulating valve connected to the volatile matter discharge pipeline, and the pressure sensor is signal-connected to the pressure regulating valve.

[0012] As a further embodiment of this utility model, the outlet of the volatile matter discharge pipeline is connected to a waste gas treatment system, which includes a quenching device and a combustion device connected in sequence.

[0013] As a further embodiment of this invention, the exhaust gas outlet of the combustion device is connected to the burner in the high-temperature sintering zone.

[0014] As a further embodiment of this invention, a high-temperature magnetic fluid seal is provided at the shaft end of the rollers passing through the refractory material cavity.

[0015] By adopting the above technical solution, this utility model will have the following beneficial effects:

[0016] By setting up a sealed pyrolysis zone and utilizing a refractory material cavity to form a physical barrier, a necessary local oxygen-free environment is created for biomass, enabling it to undergo pyrolysis and transform into biochar instead of being burned to ash in the air. This fundamentally resolves the core contradiction of conflicting process atmosphere requirements. The atmosphere lock structure effectively isolates the atmosphere from crosstalk between the sealed pyrolysis zone and the external preheating and high-temperature sintering zones, ensuring the stability of the inert atmosphere in the pyrolysis zone and guaranteeing the continuity of material transport. By connecting the inert gas supply pipeline and the volatile matter discharge pipeline, and equipping it with a gas control device, a stable micro-positive pressure and low oxygen concentration can be dynamically maintained within the pyrolysis zone. This not only prevents air infiltration but also orderly removes pyrolysis volatiles, avoiding these byproducts from contaminating the ceramic blanks or accumulating in the kiln and causing safety hazards.

[0017] Compared with existing technologies, this invention enables the traditionally difficult-to-coordinate processes of ceramic sintering and biomass pyrolysis to be completed stably and efficiently in the same continuous roller kiln, achieving true integrated production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a front view of the integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to an embodiment of this utility model;

[0020] Figure 2 for Figure 1 A side view of the integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners as described in the embodiment.

[0021] The correspondence between the labels and component names in the attached figures is as follows:

[0022] 1. Kiln body; 11. Roller conveyor; 111. Roller bar; 12. Heater; 2. Preheating zone; 3. Sealed pyrolysis zone; 31. Refractory material cavity; 4. High-temperature sintering zone; 5. Atmosphere lock structure; 6. Inert gas supply pipeline; 61. Flow control unit; 62. Oxygen content sensor; 7. Volatile matter discharge pipeline; 71. Pressure sensor; 72. Pressure regulating valve; 81. Quenching device; 82. Combustion device; 821. Combustion chamber; 9. High-temperature magnetic fluid seal. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0024] refer to Figure 1 and Figure 2 In one embodiment of the roller kiln 11 integrating pyrolysis and sintering functions provided by this utility model, the roller kiln 11 integrating pyrolysis and sintering functions is modified based on the existing roller kiln 11. The modified roller kiln 11 mainly includes a kiln body 1, rollers 11, and heaters 12. The rollers 11 are arranged inside the kiln body 1 and are composed of multiple rollers. The heaters 12 are distributed along the length of the kiln body 1. The interior of the kiln body 1 is divided into a preheating zone 2, a sealed pyrolysis zone 3, and a high-temperature sintering zone 4 along the material conveying direction.

[0025] The sealed pyrolysis zone 3 is the key component of the modification. It is an independent refractory cavity 31 constructed within the kiln body 1, corresponding to the medium-temperature section (500-800°C), using lightweight mullite bricks. This cavity completely encloses the corresponding section of the roller conveyor 11, forming a physical barrier. Atmosphere lock structures 5 are installed at both the inlet and outlet ends of the cavity to prevent atmospheric crosstalk between the cavity and the external preheating zone 2 and high-temperature sintering zone 4.

[0026] Specifically, the aforementioned atmosphere lock structure 5 employs an air curtain seal. Air curtain seals are a mature, existing technology widely used in industrial equipment requiring the isolation of different atmospheres while maintaining continuous material transport, such as heat treatment furnaces and brazing furnaces. It uses one or more rows of slit nozzles to spray inert gas (such as nitrogen) at a high speed and along a specific angle (usually at a certain angle to the opening plane), forming a uniform and stable air curtain. This air curtain has sufficient momentum and stiffness to effectively block and isolate gases of different atmospheres on both sides of the opening. Because external air is blocked by the air curtain, the internal protective gas also has difficulty penetrating and escaping. By adjusting the flow rate and pressure of the sprayed gas, the dynamic pressure head of the air curtain can be made slightly higher than the static pressure difference between the internal and external environments, thus achieving effective sealing. In this embodiment, slits are opened on the crossbeams of the kiln's inlet and outlet, and connected to nitrogen supply pipelines. Through precise control, the sprayed nitrogen forms a sealed air curtain, allowing the green billet to pass through this invisible air curtain without obstruction, achieving continuous passage without physical contact or wear.

[0027] The refractory material cavity 31 is connected to an inert gas supply pipeline 6 at its top, with the other end of the pipeline connected to a liquid nitrogen storage tank (not shown in the figure) to supply and maintain an inert atmosphere to the sealed pyrolysis zone 3. A mass flow controller (MFC) is installed on the inert gas supply pipeline 6 as a flow control unit 61. An oxygen content sensor 62 is installed inside the refractory material cavity 31. This sensor is connected to the flow control unit 61 to form a closed-loop control, ensuring that the oxygen concentration inside the refractory material cavity 31 is always below 50 ppm.

[0028] The refractory cavity 31 is also connected to a volatile matter discharge pipe 7 at its top, through which volatile matter generated by biomass pyrolysis is led out. The outlet of the volatile matter discharge pipe 7 is connected to a waste gas treatment system. This system includes a quenching device 81 and a combustion device 82 connected in sequence. The quenching device 81 uses a spray tower to rapidly cool the high-temperature gas to below 80°C, condensing and removing most of the tar. The combustion device 82 uses a burner, with its combustion chamber 821 connected to the high-temperature sintering zone 4 in the kiln. The purpose is to completely oxidize and decompose the remaining combustible non-condensable gases (mainly composed of CO, H2, CH4, etc.) after quenching, eliminating potential environmental pollution hazards and recovering their chemical energy.

[0029] Furthermore, in order to precisely control the atmosphere, a pressure sensor 71 is installed inside the refractory material cavity 31, and a pressure regulating valve 72 is installed on the volatile matter discharge pipeline 7. The pressure sensor 71 is connected to the pressure regulating valve 72 to maintain the internal pressure of the refractory material cavity 31 at a slightly positive pressure state of +10 to +15 Pa.

[0030] Furthermore, to ensure sealing, all rollers 11 passing through the refractory material cavity 31 are equipped with high-temperature magnetic fluid seals 9 at the shaft ends of their rollers 111. These seals can withstand shaft end temperatures not exceeding 120°C and effectively prevent gas leakage along the gaps between the rollers 111.

[0031] The specific workflow of this utility model is as follows:

[0032] Ceramic green bodies containing biomass are continuously placed on roller conveyor 11. The green bodies are first heated to approximately 300°C in air atmosphere in preheating zone 2 to remove moisture. Subsequently, the green bodies enter the sealed pyrolysis zone 3 through an atmosphere lock at the inlet end of the refractory material cavity 31. In this zone, precise control by an oxygen content sensor 62 and a flow control unit 61 ensures that the green bodies are heated to approximately 600°C under a strict nitrogen atmosphere, at which point the biomass is pyrolyzed into biochar. The pyrolyzed green bodies then enter the high-temperature sintering zone 4 through an atmosphere lock at the outlet end of the refractory material cavity 31, where they are heated to the required sintering temperature (1200°C) in air atmosphere. The ceramic particles sinter to form a robust skeleton, ultimately yielding a ceramic-biochar composite material.

[0033] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners, comprising a kiln body (1), rollers (11) disposed within the kiln body (1), and heaters (12) distributed along the length of the kiln body (1), characterized in that: The kiln body (1) is provided with a preheating zone (2), a sealed pyrolysis zone (3) and a high-temperature sintering zone (4) in sequence along the material conveying direction; the sealed pyrolysis zone (3) includes a refractory material cavity (31) built in the kiln body (1), which encloses the corresponding section of the roller conveyor (11) to form a physical barrier; the inlet and outlet ends of the refractory material cavity (31) are provided with atmosphere lock structures (5), and the refractory material cavity (31) is connected to an inert gas supply pipeline (6) and a volatile matter discharge pipeline (7); the inert gas supply pipeline (6) is provided with a gas control device to provide and maintain an inert atmosphere environment in the refractory material cavity (31).

2. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 1, characterized in that: The atmosphere lock structure (5) is an air curtain type seal.

3. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 1, characterized in that: The gas control device includes a flow control unit (61) connected to the inert gas supply pipeline (6) and an oxygen content sensor (62) disposed in the refractory material cavity (31). The flow control unit (61) is signal-connected to the oxygen content sensor (62).

4. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 1, characterized in that: The refractory material cavity (31) is also equipped with a pressure sensor (71) and a pressure regulating valve (72) connected to the volatile matter discharge pipeline (7). The pressure sensor (71) is signal-connected to the pressure regulating valve (72).

5. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 1, characterized in that: The outlet of the volatile matter discharge pipeline (7) is connected to an exhaust gas treatment system, which includes a quenching device (81) and a combustion device (82) connected in sequence.

6. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 5, characterized in that: The exhaust outlet of the combustion device (82) is connected to the burner of the high-temperature sintering zone (4).

7. The integrated pyrolysis sintering roller kiln for preparing nano-biological soil conditioners according to claim 1, characterized in that: The roller conveyor (11) passing through the refractory material cavity (31) has a high-temperature magnetic fluid seal (9) at the shaft end of its roller bar (111).

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