Multi-source organic solid waste baking pyrolysis system and method

Abstract

The application discloses a multi-source organic solid waste baking pyrolysis system and method, which comprises a cylinder body, and the cylinder body comprises, in sequence along the gas and material movement direction, a preheating feed chamber, a baking zone and a pyrolysis zone; the preheating feed chamber is provided with a multi-source organic solid waste feed inlet and a raw material feed inlet; the inner wall of the baking zone is provided with longitudinal ribs in the circumferential direction, and the discharge end is provided with a first annular rib extending in the circumferential direction; the working surface of the inner wall of the pyrolysis zone has a friction coefficient of 0.4-0.6, and the discharge end is provided with a second annular rib extending in the circumferential direction; and the axial length of the pyrolysis zone is at least 2 times the axial length of the baking zone. Through the three-zone fine partition structure design and the functionalized refractory lining design of the preheating drying-baking activation-raw material self-catalytic pyrolysis, the multi-source organic solid waste pyrolysis process and the directional regulation of products are realized, the problems of unstable thermal process system and easy damage of equipment under high proportion of alternative fuel are solved, and the application has the advantages of strong universality, high product energy density, stable operation and long service life.

Description

Technical Field

[0001] This invention belongs to the field of pyrolysis technology of combustible organic solid waste, and particularly relates to a multi-source organic solid waste baking pyrolysis system and method. Background Technology

[0002] Fuel substitution is one of the four major carbon emission reduction pathways recognized in the industry and has been widely promoted and applied in cement plants both domestically and internationally. Traditional cement kilns often treat organic solid waste by direct incineration or by burning it through a pre-combustion device before feeding it into the decomposer. For substitution ratios below 20%, the fuel is directly incinerated in the decomposer. For substitution ratios above 20%, a pre-combustion device is typically used to pre-combust the substitute fuel to significantly reduce the volume of substitute fuel entering the kiln, decrease the heat load in the main combustion zone of the decomposer, and improve the adaptability and substitution ratio of the cement kiln to various sources of organic solid waste. However, direct incineration easily leads to excessively high local heat loads in the decomposer. While pre-combustion devices can reduce fuel volume, the introduction of high-temperature tertiary air (above 850℃) into the pre-combustion furnace results in waste incineration temperatures reaching ~1200℃, often causing localized fuel scaling and coking within the furnace. Furthermore, direct contact between the high-temperature flame and refractory materials can cause erosion and damage to the working surfaces of the refractory materials. Furthermore, when the proportion of alternative fuels exceeds 50%, the CO concentration at the decomposition furnace outlet rises sharply, reaching 5000ppm~10000ppm, the ammonia denitrification efficiency is low, and the pollutant emission reduction effect is poor. All of the above pose challenges to the large-scale replacement of cement kiln systems.

[0003] Compared to incineration of organic solid waste, solid waste pyrolysis technology is a more advanced method for solid waste treatment. It involves high-temperature pyrolysis of organic matter in organic solid waste under anaerobic or anoxic conditions, breaking down high-molecular-weight hydrocarbon chains into a mixture of low-molecular-weight hydrocarbon-based fuel gas, medium-molecular-weight fuel oil, and carbon black. Currently, fluidized bed gasifiers are commonly used, but they have stringent requirements on the 3D size of the feed material, needing to be less than 20mm, and require a high gas supply, resulting in combustible gas with high dust content, low calorific value, low heat utilization, and large waste gas volume.

[0004] Therefore, how to achieve a high proportion of alternative fuels in cement kilns while overcoming the problems of poor material adaptability, low product calorific value, and severe scaling and wear within the system caused by existing pyrolysis technologies is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the problems of unstable thermal regimes, equipment vulnerability, and poor product controllability under high-proportion alternative fuels in existing technologies, this invention provides a multi-source organic solid waste baking pyrolysis system and method. This system employs a finely partitioned structural design of "preheating and drying - baking activation - raw material autocatalytic pyrolysis" and a functionalized refractory lining design. This not only allows for the targeted control of the pyrolysis process and product composition to obtain more reducing small-molecule gaseous products, effectively solving the problem of stable thermal regimes under high-proportion alternative fuels and reducing the impact on the stability of subsequent firing systems; it also extends the service life of the preheating system, reduces downtime maintenance, and lowers operating costs.

[0006] This invention is implemented as follows: a multi-source organic solid waste baking pyrolysis system, comprising a cylinder, wherein the cylinder comprises, in sequence along the gas and material movement direction: The preheating feeding chamber is equipped with a multi-source organic solid waste inlet and a raw material inlet, which is used to introduce high-temperature hot flue gas to preheat, dry, disperse and premix the multi-source organic solid waste and raw materials; The baking area has longitudinal ribs along its inner wall and a first ring rib extending along its circumference at the discharge end. The pyrolysis zone has an inner wall working surface configured to have a friction coefficient of 0.4 to 0.6, and the discharge end of the pyrolysis zone is provided with a second annular rib extending in the circumferential direction. The axial length of the pyrolysis zone is at least twice the axial length of the baking zone.

[0007] In the above technical solution, preferably, the preheating feed chamber is a variable diameter structure with the inlet higher than the outlet, the upper half of which is lined with high-strength wear-resistant castable, and the working surface of the lower half of which is a microcrystalline plate. The surface roughness Ra of the microcrystalline plate is ≤3.2μm, which is used to prevent material from sticking and accumulating.

[0008] In the above technical solution, preferably, the longitudinal ribs are evenly distributed along the circumference of the inner wall of the baking area, and the number is 4 to 6, and their cross-section is semi-circular or streamlined.

[0009] In the above technical solution, preferably, the longitudinal rib is welded and fixed to the cylinder by T-shaped anchors, and the longitudinal rib is connected to the T-shaped anchors by slots; the starting point of the longitudinal rib along the axial direction is fixed by heat-resistant steel, and the ending point is fixed by the first ring rib.

[0010] In the above technical solution, preferably, the first ring rib and the second ring rib are both annular protrusions that are continuous along the inner wall of the cylinder, and their protrusion height is 2% to 8% of the inner diameter of the cylinder in their respective areas; the first ring rib and the second ring rib are used to block the axial flow of materials and prolong the residence time of materials in the corresponding areas.

[0011] In the above technical solution, preferably, the lining of the non-longitudinal rib area of ​​the baking zone is made of high-alumina brick or corundum brick, wherein the Al2O3 content is ≥75%; the refractory material of the inner wall of the pyrolysis zone is made of Al-Si matrix, with 8~15wt% SiC particles added, and the working surface friction coefficient is 0.4~0.6 through phosphate bonding.

[0012] In the above technical solution, preferably, the longitudinal rib, the first annular rib and the second annular rib are corundum preforms, wherein the Al2O3 content is ≥90%.

[0013] In the above technical solution, preferably, the outlet of the pyrolysis zone is provided with a discharge chamber, and a high-temperature kiln camera is installed on the wall of the discharge chamber to monitor the material movement status and multi-point temperature field distribution in different areas in real time.

[0014] The present invention also provides a method for baking and pyrolysis of multi-source organic solid waste using the above system, comprising the following steps: Multi-source organic solid waste and raw materials are fed into the preheating feed chamber from the multi-source organic solid waste inlet and the raw material inlet, respectively, and are preheated, dried, dispersed and premixed by contacting with high-temperature hot flue gas. The premixed material then enters the baking zone, where the temperature is controlled at 500-800℃. The longitudinal ribs guide the material to roll and the first ring ribs block the material from moving axially, thus extending the residence time of the material in the baking zone and strengthening the mixing of the material, and thus activating it through baking. After baking, the material enters the pyrolysis zone, where the temperature is controlled at 700–1000℃ and the total filling rate is controlled at 0.3–0.4. The inner wall and second ring ribs with a friction coefficient of 0.4–0.6 are used to form a rolling bed to enhance the mixing of raw materials and multi-source organic solid waste. The CaO, Fe2O3, and Al2O3 components in the raw materials are used to catalyze the pyrolysis reaction, producing pyrolysis products rich in small molecule reducing gases.

[0015] In the above technical solution, preferably, by adjusting the friction coefficient of the inner wall of the pyrolysis zone and the height of the second ring rib, the average residence time and tumbling frequency of the material in the pyrolysis zone are controlled, thereby regulating the proportion of solid phase, liquid phase and gas phase in the pyrolysis product.

[0016] In the above technical solution, preferably, the temperature of the baking zone is controlled by adjusting the residence time of the material in the preheating feeding chamber and the flow rate of the high-temperature hot flue gas; the temperature of the pyrolysis zone is controlled by adjusting the rotation speed of the cylinder and the raw material feeding amount.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The present invention has a preheating treatment process of preheating-baking-pyrolysis, which makes it universally applicable to multi-source organic solid waste with complex sources, different shapes and large fluctuations in moisture content.

[0018] (2) This invention solves the technical problems of easy scaling and unstable thermal regime of pre-combustion device under high proportion of alternative fuel by the partition coupling of "baking + pyrolysis" and "functional design of refractory materials".

[0019] (3) The present invention enables precise zone control of the baking pyrolysis system, including preheating and drying in the preheating feed chamber, baking and activation in the baking zone, and autocatalytic pyrolysis in the pyrolysis zone. Each zone transmits to the material layer through cylinder wall conduction and high-temperature gas radiation. The residence time is adjusted by the cylinder rotation speed, thereby controlling the pyrolysis process and improving the energy density of the combustible gas in the finished product. The pyrolysis products rich in small molecule reducing gases are obtained through raw material catalysis, which is beneficial to reducing CO and NOx emissions from the cement kiln system.

[0020] (4) This invention, through the synergistic structural design of longitudinal ribs and refractory material friction coefficient (affecting material tumbling) and ring rib structure (affecting residence time), strengthens the mixing of raw materials and combustible multi-source organic solid waste, achieving precise control over material residence time, tumbling frequency, and the final pyrolysis product (solid / liquid / gas) ratio. It promotes the autocatalytic effect of raw materials, fully utilizes the catalytic cracking effect of elements such as CaO, Fe2O3, and Al2O3 on macromolecular hydrocarbon gases, and increases the volume concentration of small molecule reducing gases (CO, H2, CH4), which is beneficial for reducing CO and NO in the cement kiln system. X emission.

[0021] (5) The present invention effectively extends the service life of the baking pyrolysis system, reduces the frequency of furnace shutdown and maintenance, and significantly reduces operating costs by using the anti-sticking and anti-clogging design (microcrystalline plate) of the preheating feed chamber and the wear-resistant / erosion-resistant refractory material configuration of each functional area. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the internal structure of the baking pyrolysis system provided in an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the internal structure of the baking pyrolysis system provided in an embodiment of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the radial cross-sectional structure of the baking zone provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the first ring rib structure with longitudinal ribs n=6 provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the first ring rib structure with longitudinal ribs n=4 provided in an embodiment of the present invention; Figure 6This is a schematic diagram of the baking pyrolysis system of the present invention in a cement kiln application scenario.

[0023] In the diagram: 1. Air inlet duct; 2. Preheating feed chamber; 2-1. Multi-source organic solid waste feed inlet; 2-2. Raw material feed inlet; 3. Rotary baking pyrolysis furnace; 3-1. Baking zone; 3-2. Pyrolysis zone; 4. Discharge chamber; 4-1. Air duct; 4-2. Material pipe; C1. Microcrystalline plate; C2. High-alumina wear-resistant castable; B1. High-alumina brick or corundum brick; B2. Modified Al-Si brick; P1. First ring rib; P2. Second ring rib; P3. Longitudinal rib; T: T-type anchor; A. Gradient combustion decomposition furnace; B. Kiln tail smoke chamber. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Example 1 Please see Figures 1-5 This invention provides a multi-source organic solid waste baking pyrolysis system, including a cylinder, which includes a preheating feed chamber 2, a baking zone 3-1 and a pyrolysis zone 3-2 in sequence along the gas and material movement direction.

[0028] The preheating feed chamber 2 is equipped with a multi-source organic solid waste feed inlet 2-1 and a raw material feed inlet 2-2 at the top, which are used to introduce high-temperature hot flue gas to preheat, dry, disperse and premix the multi-source organic solid waste and raw materials; Baking zone 3-1 has longitudinal ribs P3 along its inner wall and a first ring rib P1 extending along its circumference at the discharge end, in order to promote the mixing of raw materials and combustible multi-source organic solid waste and improve the baking activation effect. The pyrolysis zone 3-2 has an inner wall working surface configured to have a friction coefficient of 0.4 to 0.6, and the discharge end of the pyrolysis zone 3-2 is provided with a second annular rib P2 extending in the circumferential direction. The axial length of the pyrolysis zone 3-2 is at least twice the axial length of the baking zone 3-1.

[0029] By employing a three-section structure—"preheating feed chamber 2 - baking zone 3-1 - pyrolysis zone 3-2"—arranged sequentially along the material movement direction, this invention achieves graded thermal treatment of multi-source organic solid waste. The preheating feed chamber 2 utilizes high-temperature flue gas to initially dry and disperse materials with complex compositions and fluctuating moisture content, improving material homogeneity and flowability. The baking zone 3-1 extends the material residence time through longitudinal ribs P3 and the first ring rib P1, enhancing heat and mass transfer to achieve dehydration and preliminary pyrolysis. The pyrolysis zone 3-2, by controlling the inner wall friction coefficient and the second ring rib P2, creates an ideal rolling bed motion state, significantly enhancing material mixing. By setting the length of the pyrolysis zone 3-2 to more than twice that of the baking zone 3-1, the catalytic pyrolysis reaction of the raw materials is ensured to proceed fully, making the pyrolysis process and product composition directionally controllable and adjustable. Compared to the stringent requirements for feed size in traditional fluidized bed gasifiers, this invention is universally applicable to multi-source organic solid waste with complex origins, varying shapes, and large fluctuations in moisture content.

[0030] Furthermore, the length of baking zone 3-1 varies depending on the type of multi-source organic solid waste. When the multi-source organic solid waste is municipal solid waste with high moisture content or agricultural and forestry biomass with a relatively dense structure, baking can achieve dechlorination and control the alkali metal form, improving the cleanliness and efficiency of thermal conversion. In this case, the length of baking zone 3-1 should be appropriately extended. When the multi-source organic solid waste is straw biomass, baking can remove unstable components such as volatiles, making it closer to the standard of conventional fuels. In this case, the length of baking zone 3-1 should be moderate.

[0031] The high-temperature hot flue gas in the preheating feed chamber 2 has a wind speed of 18~25m / s, which is used to preheat, disperse and premix the multi-source organic solid waste and raw materials entering the chamber.

[0032] In a preferred embodiment, the preheating feed chamber 2 has a variable diameter structure with the inlet higher than the outlet. The upper half of the chamber is lined with high-alumina wear-resistant castable C2, and the working surface of the lower half is a microcrystalline plate C1. The surface roughness Ra of the microcrystalline plate C1 is ≤3.2μm, which is used to prevent material from sticking and accumulating.

[0033] Specifically, the preheating feed chamber 2 adopts a circular variable diameter design with the inlet higher than the outlet, and the bottom plate has an angle of ≥45° with the horizontal, allowing materials to slide naturally under gravity and preventing accumulation. The top is equipped with at least one multi-source organic solid waste inlet 2-1 and one raw material inlet 2-2, through which high-temperature hot flue gas is introduced to preheat, dry, disperse, and premix the multi-source organic solid waste. The upper part of the preheating feed chamber 2 is where hot air is blown, requiring enhanced wear resistance of the refractory material. High-alumina wear-resistant castable C2 is selected, which can effectively resist the erosion and wear caused by long-term blowing of high-temperature hot air at 18~25m / s. The lower working surface uses microcrystalline plate C1 (Ra≤3.2μm) with extremely low surface roughness. Utilizing its smooth surface characteristics, it avoids materials sticking to the wall surface and causing accumulation of multi-source organic solid waste. It significantly reduces the adhesion tendency of wet or semi-dry materials, solves the industry problem of high moisture and high viscosity multi-source organic solid waste easily sticking and clogging at the feed inlet, and ensures the continuous and stable operation of the system.

[0034] The rotary baking pyrolysis furnace 3 is divided into a baking zone 3-1 and a pyrolysis zone 3-2.

[0035] Baking zone 3-1 is mainly for baking and activation. This stage is endothermic, with a temperature of 500-800℃, which is regulated by the residence time of multi-source organic solid waste in preheating feed chamber 2 and the flow rate of high-temperature hot flue gas. Baking zone 3-1 primarily involves hemicellulose decomposition, dehydroxylation, and dechlorination.

[0036] In a preferred embodiment, the longitudinal ribs P3 are evenly distributed along the inner wall of the baking zone 3-1, with a quantity n of 4 to 6, and their cross-section is semi-circular or streamlined, used to guide the material to roll and prevent the material from sticking together.

[0037] Specifically, the circumferentially evenly distributed longitudinal ribs P3 effectively lift the material from the bottom of the cylinder to a certain height before it falls back down during cylinder rotation, forming a "throwing" or "rolling" motion that significantly enhances material mixing. The semi-circular or streamlined cross-section design effectively eliminates sharp edges, preventing material from adhering to the surface. The number of longitudinal ribs P3 can be adjusted according to the material characteristics; the higher the moisture content of multi-source organic solid waste, the more longitudinal ribs P3 are needed (e.g., n=6) to provide stronger stirring ability, thereby improving the baking and activation effect.

[0038] In a preferred embodiment, the longitudinal rib P3 is welded and fixed to the cylinder by a T-shaped anchor T, and the longitudinal rib P3 is connected to the T-shaped anchor T by a slot; the starting point of the longitudinal rib P3 along the axial direction is fixed by heat-resistant steel, and the ending point is fixed by the first ring rib P1.

[0039] Specifically, a connection method combining T-shaped anchors (T) and slots is adopted to achieve reliable mechanical fixation between the longitudinal rib P3 and the cylinder, avoiding the risk of detachment caused by thermal stress or mechanical force under high-temperature dynamic conditions, which is not possible with castable refractory bricks alone. The starting point of the longitudinal rib P3 along the axial direction is fixed by heat-resistant steel, and the ending point is fixed by the first ring rib P1, forming a stable axial positioning. This ensures the positional accuracy and structural integrity of the longitudinal rib P3 during long-term rotational operation, significantly improving the service life of the equipment.

[0040] In a preferred embodiment, the first annular rib P1 is a continuous annular protrusion structure along the inner wall of the cylinder, and its protrusion height is 2% to 8% of the inner diameter of the cylinder in the baking zone 3-1; the first annular rib P1 is used to block the axial flow of materials and prolong the residence time of materials in the baking zone 3-1.

[0041] Specifically, the first ring rib P1 acts as a "weir" along the axial direction of the baking zone 3-1, effectively increasing the average residence time of materials in the baking zone 3-1. The first ring rib P1 is composed of several wedge-shaped prefabricated pieces assembled circumferentially. The prefabricated pieces near the pyrolysis zone 3-2 are wedge-shaped, while those near the baking zone 3-1, except for the square prefabricated pieces contacting the longitudinal rib P3, are also wedge-shaped. The end faces of the square prefabricated pieces are planes perpendicular to the cylinder axis, used for axial fixation of the longitudinal rib P3. The protrusion height of the first ring rib P1 is 2-8% of the inner diameter of the baking zone 3-1, balancing flow control and material throughput. For common combustible multi-source organic solid waste types, the baking time required for municipal solid waste and wood-based biomass is much longer than that for straw-based biomass. Generally, due to the high lignin content and thermal stability of wood-based fuels, the height of the first ring rib P1 needs to be appropriately increased to ensure sufficient residence time. Municipal solid waste typically contains ~30% moisture, and the first ring rib P1 ensures sufficient dehydroxylation time during the baking stage. Therefore, by adjusting the height of the first ring rib P1, the residence time can be flexibly controlled according to the characteristics of different multi-source organic solid wastes, achieving targeted optimization of process parameters.

[0042] In a preferred embodiment, the lining of the non-longitudinal rib area of ​​the baking zone 3-1 is made of high-alumina bricks or corundum bricks, wherein the Al2O3 content is ≥75%.

[0043] Specifically, the lining of the non-longitudinal rib area of ​​baking zone 3-1 is made of high-alumina bricks or corundum bricks B1 with corundum-mullite crystal phase or corundum as the main component. This gives baking zone 3-1 good thermal shock resistance during the heat absorption stage of 500-800℃, while also having high high-temperature strength, corrosion resistance and good wear resistance, and can resist thermal shock and material wear.

[0044] Pyrolysis zone 3-2 primarily involves pyrolysis of the raw materials under autocatalytic action. This stage requires enhanced mixing between material particles, operating in a reducing atmosphere at 700-1000℃. Generally, when the friction coefficient of the inner wall of the cylinder is low, sliding motion is dominant, with relatively little movement between particles. When the friction coefficient is high, solid waste particles form a rolling layer on the bed surface. The particle speed along the rotation direction in the lower part of the bed is relatively stable. Particles within the layer continuously roll, and particles near the bed surface enter the rolling layer and move along with other particles within it. Particles continuously roll from the upper half of the bed to the lower half.

[0045] To maximize the effective mixing and contact between multi-source organic solid waste and raw materials, and improve pyrolysis efficiency, when the total filling rate of multi-source organic solid waste + raw materials in the cylinder is between 0.3 and 0.4, the friction coefficient of the refractory material on the wall of pyrolysis zone 3-2 needs to be controlled between 0.4 and 0.6, and a second ring rib P2 is provided at its discharge end. By adjusting the friction coefficient of the refractory material in pyrolysis zone 3-2 and the height of the second ring rib P2, the average residence time and tumbling frequency of the material in pyrolysis zone 3-2 can be controlled, thereby adjusting the proportion of solid, liquid, and gas phases in the pyrolysis products.

[0046] In a preferred embodiment, the second ring rib P2 is a continuous annular protrusion structure along the inner wall of the cylinder, and its protrusion height is 2% to 8% of the inner diameter of the cylinder in the pyrolysis zone 3-2; the second ring rib P2 is used to block the axial flow of materials and prolong the residence time of materials in the pyrolysis zone 3-2.

[0047] Specifically, the second ring rib P2 acts as a "weir" along the axial direction of the pyrolysis zone 3-2, effectively increasing the average residence time of materials in the pyrolysis zone 3-2. The second ring rib P2 is composed of several prefabricated pieces assembled circumferentially. The prefabricated pieces closer to the pyrolysis zone 3-2 are wedge-shaped, while those closer to the discharge chamber 4 are square. The protrusion height of the second ring rib P2 is 2-8% of the inner diameter of the pyrolysis zone 3-2, balancing flow control and material throughput. For multi-source organic solid waste with high carbon content, the height of the second ring rib P2 can be appropriately increased to extend the pyrolysis time.

[0048] In a preferred embodiment, the refractory material of the inner wall of the pyrolysis zone 3-2 is a modified Al-Si brick B2, which adopts an Al-Si matrix and adds 8~15wt% SiC particles. It is bonded by phosphate to make the friction coefficient of the working surface 0.4~0.6.

[0049] Specifically, pyrolysis zone 3-2 employs innovative functionalized refractory materials: a matrix modification method is used, introducing 8-15 wt% of high-friction-coefficient second-phase particles (SiC) into the Al-Si high-alumina brick matrix, bonded with phosphate, to improve the brick's friction coefficient. After heat treatment at 600℃, this refractory brick forms an amorphous network structure that firmly "holds" the aggregate particles, thus maintaining a stable microscopic morphology at high temperatures, achieving a working surface friction coefficient of 0.4-0.6, enabling the material to form a rolling bed within pyrolysis zone 3-2. This design allows the refractory working surface to maintain a stable friction coefficient of 0.4-0.6 even in a reducing atmosphere at 700-1000℃, providing crucial wall conditions for the formation of an efficient rolling bed within pyrolysis zone 3-2.

[0050] In a preferred embodiment, the outlet of the pyrolysis zone 3-2 is provided with a discharge chamber 4, and a high-temperature kiln camera is installed on the wall of the discharge chamber 4 to monitor the material movement status and multi-point temperature field distribution in different areas in real time.

[0051] Specifically, the installation of cameras in high-temperature kilns allows operators to observe key information such as the material's tumbling state, layer thickness, and crusting tendency in real time and intuitively, and to make comprehensive judgments based on multi-point temperature field data. This design provides a visual basis for precise control of process parameters (such as adjusting the kiln rotation speed and raw material feed rate), and is an important monitoring means to ensure the stable and safe operation of the system within the target temperature range of 700-1000℃.

[0052] In a preferred embodiment, the longitudinal rib P3, the first annular rib P1, and the second annular rib P2 are corundum preforms, wherein the Al2O3 content is ≥90%.

[0053] Specifically, the longitudinal rib P3 and the annular rib, as components that come into direct, high-frequency contact with materials and are subject to the most severe impact and wear, require surfaces that are as smooth as possible while also possessing wear resistance. High-purity corundum (Al2O3≥90%) prefabricated components are used, leveraging their ultra-high hardness and smooth surface characteristics. While providing a certain degree of agitation and blocking effect, this minimizes material adhesion and wear rates on their surfaces, extending the replacement cycle of these critical wear parts and reducing maintenance costs.

[0054] Example 2 like Figure 6 As shown, this embodiment of the invention also provides a method for baking and pyrolyzing multi-source organic solid waste using the above system, comprising the following steps: Multi-source organic solid waste and raw materials are fed into the preheating feed chamber 2 from the multi-source organic solid waste inlet 2-1 and the raw material inlet 2-2, respectively, and are preheated, dried, dispersed and premixed by contacting with high-temperature hot flue gas. The premixed material then enters the baking zone 3-1, where the temperature is controlled at 500-800℃. The longitudinal rib P3 guides the material to roll and the first ring rib P1 blocks the material from moving axially, thus extending the residence time of the material in the baking zone 3-1 and strengthening the mixing of the material for baking activation. After baking, the material enters the pyrolysis zone 3-2. The temperature of the pyrolysis zone 3-2 is controlled at 700-1000℃, and the total filling rate of the material is controlled at 0.3-0.4. The inner wall and the second ring rib P2 with a friction coefficient of 0.4-0.6 are used to form a rolling bed to enhance the mixing of raw materials and multi-source organic solid waste. The CaO, Fe2O3 and Al2O3 components in the raw materials are used to catalyze the pyrolysis reaction to produce pyrolysis products rich in small molecule reducing gases.

[0055] The hot flue gas inlet of the preheating feed chamber 2 is connected to the kiln tail flue chamber B of the cement kiln system through a pipeline; the discharge chamber at the outlet of the pyrolysis zone 3-2 is connected to the kiln tail flue chamber B through the lower feed pipe 4-2; the discharge chamber is connected to the reduction zone of the gradient combustion decomposition furnace A through the upper air duct 4-1.

[0056] This method utilizes 1100℃ oxygen-deficient hot air provided by the cement kiln system, requiring no additional heat source and achieving energy efficiency. In the preheating feed chamber 2, high-speed hot air at 18-25 m / s disperses and premixes the materials. In the baking zone 3-1, the temperature is controlled at 500-800℃, focusing on the decomposition, dehydroxylation, and dechlorination of hemicellulose. In the pyrolysis zone 3-2, by controlling the filling rate (0.3~0.4) and the high friction coefficient inner wall (0.4-0.6), the materials form a "rolling layer," with particles continuously rolling off the bed surface, greatly increasing the contact area and mixing intensity between multi-source organic solid waste and raw materials. Elements such as CaO, Fe2O3, and Al2O3 in the raw materials catalyze the cracking of large molecular hydrocarbon gases produced by pyrolysis, breaking them down into smaller molecular gases, significantly improving the energy density of the produced combustible gas.

[0057] In a preferred embodiment, by adjusting the friction coefficient of the inner wall of the pyrolysis zone 3-2 and the height of the second ring rib P2, the average residence time and tumbling frequency of the material in the pyrolysis zone 3-2 are controlled, thereby regulating the proportion of solid, liquid and gas phases in the pyrolysis products.

[0058] Specifically, by coordinating the adjustment of these two parameters, operators can flexibly and directionally control the proportion of pyrolysis products according to the needs of the solid, liquid, and gas phases, thereby optimizing the product structure.

[0059] In a preferred embodiment, the temperature of the baking zone 3-1 is controlled by adjusting the residence time of the material in the preheating feed chamber 2 and the flow rate of the high-temperature hot flue gas; the temperature of the pyrolysis zone 3-2 is controlled by adjusting the rotation speed of the cylinder and the raw material feeding amount.

[0060] Specifically, this method provides independent and precise temperature control. The temperature of the baking zone 3-1 (500-800℃) is mainly regulated by the flow rate of the introduced high-temperature hot flue gas and the residence time of the material in the preheating feed chamber 2, avoiding a decrease in energy density due to excessive gas volume. The temperature of the pyrolysis zone 3-2 (700-1000℃) is controlled by the cylinder rotation speed and the raw material feeding rate. This control method allows the entire pyrolysis process to rely mainly on cylinder wall conduction and high-temperature gas radiation to feed the material layer (including multi-source organic solid waste and raw materials), improving the energy density of the finished combustible gas and achieving a low-energy-consumption, high-value heat treatment effect.

[0061] like Figure 6 As shown, during operation, the system draws high-temperature, oxygen-deficient air (approximately 1100℃ and ≤5% oxygen content) from the cement kiln flue gas chamber online, which is then fed into the preheating feed chamber 2 through air inlet duct 1. Multi-source organic solid waste (such as municipal solid waste and biomass) and raw materials are fed in through the multi-source organic solid waste inlet 2-1 and the raw material inlet 2-2, respectively. Inside the preheating feed chamber 2, high-speed hot air disperses, preheats, dries, and initially mixes the materials.

[0062] Subsequently, the material enters the baking zone 3-1 of the rotary baking pyrolysis furnace. The inner wall of this zone is equipped with longitudinal ribs P3, and the discharge end has a first annular rib P1. At 500-800℃, the material is repeatedly agitated and propelled forward by the longitudinal ribs P3, while the first annular rib P1 prolongs its residence time, completing the baking activation reaction.

[0063] The material then enters the pyrolysis zone 3-2. The inner wall of this zone is made of modified refractory bricks with a high coefficient of friction (0.4-0.6), and a second ring rib P2 is installed at the discharge end. At 700-1000℃, the material filling rate is controlled at 0.3-0.4, forming a rolling bed where the raw material and multi-source organic solid waste are vigorously mixed. Components such as CaO in the raw material catalyze the cracking of large molecular hydrocarbons into small molecule reducing gases such as CO, H2, and CH4. Finally, the generated pyrolysis gases are discharged from the upper air duct 4-1 of the discharge chamber 4, and the ash and slag are discharged from the lower material pipe 4-2 of the discharge chamber 4, respectively sent to the reduction zone of the gradient combustion decomposition furnace A and the kiln tail flue gas chamber B of the cement kiln system, achieving resource utilization and harmless disposal.

[0064] In summary, this system utilizes the high-temperature, oxygen-deficient air (temperature ~1100℃, ≤5% O2) from the cement kiln system's flue gas chamber as the ignition heat source. Through the zoned coupling of "preheating and drying - baking and activation - raw material autocatalytic pyrolysis" and the functional design of refractory materials, the pyrolysis process and product composition are directionally controllable and adjustable, resulting in more reducing small molecule gaseous products. The generated, directionally controllable pyrolysis gaseous components rich in reducing small molecules enter the reduction zone of the gradient combustion decomposition furnace in the cement kiln's firing system to reduce NO. X Reduce CO and NO at the outlet of the gradient combustion decomposition furnace XThe concentration is increased, and the efficiency of ammonia water is improved, so that the thermal treatment of combustible solid waste in cement kilns has the beneficial effects of low energy consumption, low emissions, and high value.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-source organic solid waste baking pyrolysis system, comprising a cylinder, characterized in that, The cylinder, along the direction of gas and material movement, comprises, in sequence: The preheating feeding chamber is equipped with a multi-source organic solid waste inlet and a raw material inlet, which is used to introduce high-temperature hot flue gas to preheat, dry, disperse and premix the multi-source organic solid waste and raw materials; The baking zone has longitudinal ribs along its inner wall and a first ring rib extending along its circumference at the discharge end of the baking zone. The pyrolysis zone has an inner wall working surface configured to have a friction coefficient of 0.4 to 0.6, and the discharge end of the pyrolysis zone is provided with a second ring rib extending in the circumferential direction. The axial length of the pyrolysis zone is at least twice the axial length of the baking zone.

2. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The preheating feed chamber has a variable diameter structure with the inlet higher than the outlet. The upper half of the chamber is lined with high-strength wear-resistant castable, and the working surface of the lower half of the chamber is a microcrystalline plate. The surface roughness Ra of the microcrystalline plate is ≤3.2μm, which is used to prevent material from sticking and accumulating.

3. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The longitudinal ribs are evenly distributed along the circumference of the inner wall of the baking area, with a quantity of 4 to 6, and their cross-section is semi-circular or streamlined.

4. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The longitudinal ribs are welded and fixed to the cylinder by T-shaped anchors, and the longitudinal ribs are connected to the T-shaped anchors by slots; the starting point of the longitudinal ribs along the axial direction is fixed by heat-resistant steel, and the ending point is fixed by the first ring rib.

5. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, Both the first and second annular ribs are continuous annular protrusions along the inner wall of the cylinder, and their protrusion height is 2% to 8% of the inner diameter of the cylinder in their respective areas; the first and second annular ribs are used to block the axial flow of materials and prolong the residence time of materials in the corresponding areas.

6. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The lining of the non-longitudinal rib area of ​​the baking zone is made of high-alumina bricks or corundum bricks, wherein the Al2O3 content is ≥75%; The refractory material on the inner wall of the pyrolysis zone adopts an Al-Si matrix and adds 8~15wt% SiC particles. It is bonded by phosphate to make the friction coefficient of the working surface 0.4~0.

6.

7. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The longitudinal rib, the first annular rib, and the second annular rib are corundum preforms with an Al2O3 content ≥90%.

8. The multi-source organic solid waste baking pyrolysis system according to claim 1, characterized in that, The outlet of the pyrolysis zone is equipped with a discharge chamber, and a high-temperature kiln camera is installed on the wall of the discharge chamber to monitor the material movement status and multi-point temperature field distribution in different areas in real time.

9. A method for baking and pyrolysis of multi-source organic solid waste using the system described in any one of claims 1 to 8, characterized in that, Includes the following steps: Multi-source organic solid waste and raw materials are fed into the preheating feed chamber from the multi-source organic solid waste inlet and the raw material inlet, respectively, and are preheated, dried, dispersed and premixed by contacting with high-temperature hot flue gas. The premixed materials then enter the baking zone, where the temperature is controlled at 500–800°C. The longitudinal ribs guide the material to roll and the first ring ribs block the axial movement of the material, extending the residence time of the material in the baking zone and strengthening the mixing of the material, thus activating the baking process. After baking, the material enters the pyrolysis zone, where the temperature is controlled at 700–1000℃ and the total filling rate is controlled at 0.3–0.

4. The inner wall and second ring ribs with a friction coefficient of 0.4–0.6 are used to form a rolling bed to enhance the mixing of raw materials and multi-source organic solid waste. The CaO, Fe2O3, and Al2O3 components in the raw materials are used to catalyze the pyrolysis reaction, producing pyrolysis products rich in small molecule reducing gases.

10. The method for baking and pyrolysis of multi-source organic solid waste according to claim 9, characterized in that, By adjusting the friction coefficient of the inner wall of the pyrolysis zone and the height of the second ring rib, the average residence time and tumbling frequency of the material in the pyrolysis zone are controlled, thereby regulating the proportion of solid, liquid and gas phases in the pyrolysis products.

11. The method for baking and pyrolysis of multi-source organic solid waste according to claim 9, characterized in that, The temperature of the baking zone is controlled by adjusting the residence time of the material in the preheating feed chamber and the flow rate of the high-temperature hot flue gas; the temperature of the pyrolysis zone is controlled by adjusting the rotation speed of the cylinder and the raw material feeding amount.

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