A split rotary kiln and a method for burning materials

Abstract

The present invention relates to the technical field of industrial kilns, and in particular to a split rotary kiln and a method for burning materials. The split rotary kiln of the present invention comprises a cylinder, which comprises a feeding section, a drying section, an enthalpy-increasing combustion section, and a stable combustion section that are connected to each other. The drying section, the enthalpy-increasing combustion section, and the stable combustion section are all provided with a material guiding mechanism, and the stable combustion section is provided with a burner; a gas exhaust channel is provided at the top of the feeding section; the high-temperature flue gas released by the combustion of the material in the stable combustion section moves toward the material in the cylinder; and it also includes a waste heat steam generating section. The split rotary kiln of the present invention adopts a graded combustion process, which allows materials with a certain calorific value to burn stably while also improving combustion efficiency, greatly optimizing traditional combustion equipment and processes.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial kilns, and in particular to a split rotary kiln and a material combustion method. Background Art

[0002] A rotary kiln refers to a rotary calcining kiln (commonly known as a rotary kiln). In many production industries such as building materials, metallurgy, chemical industry, and environmental protection, rotary kilns are widely used to perform mechanical, physical or chemical treatment on solid materials.

[0003] Traditional rotary kilns use direct material combustion, requiring the calorific value of the material to reach a certain level to ensure stable combustion and continuous operation. However, the existing direct material feeding method cannot guarantee sufficient time for the material to heat up. Furthermore, excessive moisture content in the material also prevents the material's enthalpy from increasing in a short period of time. Furthermore, due to the limitations of the ambient temperature field, rotary kilns cannot establish the large stable combustion space that traditional fluidized bed or grate furnaces can. Therefore, when large quantities of low-calorific-value materials are fed into the kiln for combustion, maintaining stable combustion is extremely difficult.

[0004] The traditional rotary kiln combustion method is to use one or a combination of the following methods to establish a stable combustion state and improve combustion efficiency: continuous heating and continuous oxygen introduction, reducing the physical particle size of the material, simply heating the material to increase the material temperature (from the unheated material to the combustible temperature) and then a small amount of supplementary combustion, increasing the heat treatment environment temperature, etc. Although the above methods can also burn the material stably, the implementation of the process requires the assistance of multiple additional equipment systems, which increases the difficulty and economic cost of the process implementation, and also causes energy loss and waste.

[0005] Because the traditional treatment method is direct combustion, new research shows that the stable combustion temperature range in the rotary kiln tube can be increased to above 1200℃ to ensure the complete combustion of difficult-to-burn materials. However, at the same time, the content of thermal nitrogen oxides at the exhaust end will increase significantly, leading to increased exhaust treatment costs and large-scale emissions of pollutants.

[0006] Taking gasification slag as an example, in order to ensure stable combustion in the traditional rotary kiln mode, the temperature field in the rotary kiln needs to be raised to above 1200℃ before the slag shell can be opened to release the combustible carbon inside. However, the melting point of gasification slag ash is between 1150℃ and 1300℃. Therefore, the slag discharge state under this process condition becomes system liquid slag discharge, which increases the difficulty and cost of slag discharge.

[0007] Moreover, the traditional method only has a mechanical lifting device. The material can be grabbed by the guide plate and thrown into the inner cavity space under the action of the mechanical guide plate. The rest of the time, the material is piled up in the rotating upward space in the cavity. Therefore, except for the material on the surface of the pile, the rest of the material cannot fully contact with the oxygen required for the oxidation reaction. Therefore, the oxidation reaction rate of the material is low, and a longer residence time and afterburning are required to ensure the oxidation efficiency of the material. Summary of the Invention

[0008] In view of the above-mentioned defects of the prior art, the present invention provides a split rotary kiln and a material combustion method.

[0009] The technical solution of the present invention to solve the above technical problems is as follows:

[0010] A first aspect of the present invention provides a split rotary kiln, comprising a cylinder, wherein the cylinder comprises an inner cylinder and an outer cylinder arranged coaxially, and a gap is provided between the inner cylinder and the outer cylinder;

[0011] The cylinder includes a feeding section, a drying section, an enthalpy-increasing combustion section, and a stable combustion section which are connected and arranged along the movement direction of the material. The temperature of the material in the drying section, the enthalpy-increasing combustion section, and the stable combustion section increases gradually. The drying section, the enthalpy-increasing combustion section, and the stable combustion section are all provided with a material guiding mechanism, and the stable combustion section is provided with a burner;

[0012] A heat-insulating material guiding mechanism is further provided between the combustion stabilization section and the enthalpy-increasing combustion section;

[0013] A gas discharge channel is provided at the top of the feed section;

[0014] The high-temperature flue gas released by the combustion of the material in the stable combustion section moves towards the material in the cylinder, and the material moves in the inner cylinder, and the high-temperature flue gas moves in the gap;

[0015] It also includes a waste heat steam generating section for transporting the high-temperature flue gas from the stable combustion section to the enthalpy-increasing combustion section.

[0016] On the basis of the above technical solution, the present invention can also make the following improvements:

[0017] Furthermore, after passing through the drying section, the material temperature rises to above 80°C; after passing through the enthalpy-increasing combustion section, the material temperature rises to above 120°C; and the temperature of the material burning in the stable combustion section is 700-950°C.

[0018] Furthermore, the combustion stabilization section is also provided with a centrifugal air blower.

[0019] Furthermore, the centrifugal air blower includes a plurality of high-pressure air outlets arranged at intervals, and the air outlet directions of the high-pressure air outlets are centrifugally arranged.

[0020] Furthermore, the material guiding mechanism includes a plurality of material guiding plates, which are arranged on the inner wall of the inner cylinder and arranged in sequence in a spiral shape.

[0021] Furthermore, the material guiding mechanism of the enthalpy-increasing combustion section is a reciprocating material guiding mechanism.

[0022] Furthermore, the feeding section, drying section and enthalpy-increasing combustion section are arranged in series in sequence along the horizontal direction, and the heat-insulating material guiding mechanism is extended along the vertical direction.

[0023] Furthermore, it also includes a discharge and cooling slag mechanism, one end of which is connected to an end of the stable combustion section away from the heat preservation and material guiding mechanism, and the other end is connected to the waste heat steam generating section.

[0024] Furthermore, the temperature of the material discharged from the stable combustion zone is 400-600°C.

[0025] A second aspect of the present invention provides a material combustion method using the above-mentioned split rotary kiln, comprising the following steps:

[0026] (1) Feeding: The material is transported to the drying section through the feeding section;

[0027] (2) Water evaporation: Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer, and the free water and part of the crystallized water in the material are carried to the gas discharge channel by the high-temperature flue gas;

[0028] (3) Preheating enthalpy increase: Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer, the material's own enthalpy value increases, and part of the material has been ignited, undergoing surface combustion or existing in the state of sparks;

[0029] (4) Stable combustion: After the material and gas are mixed, they enter a stable combustion state and continuously release heat. The heat mixes with the gas and forms high-temperature flue gas after heat exchange.

[0030] Compared with the prior art, the present invention has the following technical effects:

[0031] The split rotary kiln of the present invention adopts a staged combustion process, that is, a method of first raising the temperature of the material to be burned to a combustible temperature and then igniting the material. The material is first subjected to water evaporation and preheating to increase enthalpy before combustion. This allows difficult-to-burn materials with a certain calorific value to be stably burned while also improving the combustion efficiency of the material and simplifying the traditional combustion process, greatly optimizing the traditional combustion equipment, process and method. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A side view of a split rotary kiln according to an embodiment of the present invention is shown;

[0033] Figure 2A side view showing the stable combustion section of a split rotary kiln;

[0034] Figure 3 Show Figure 2 Cross-sectional view along CC direction;

[0035] Reference numerals:

[0036] 1. Feeding section;

[0037] 2. Drying section;

[0038] 3. Enthalpy-increasing combustion section;

[0039] 4. Combustion stabilization section; 41. Burner; 42. Centrifugal air blower; 43. High-pressure air outlet; 44. Combustion stabilization isolation mechanism; 45. High-pressure air supply channel; 46. Second screw feeder;

[0040] 5. Guide plate; 6. Slag discharge port; 7. Thermocouple; 8. Support wheel; 9. Transmission gear; 10. Discharge and slag cooling mechanism;

[0041] 11. Gas exhaust channel; 12. Screw feeder; 13. Insulation material guiding mechanism; 14. Waste heat steam generating section; 15. Cylinder; 16. Refractory layer; 18. Heat exchange module. DETAILED DESCRIPTION

[0042] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0043] See also Figure 1-3The split rotary kiln of the present invention includes a cylinder 15, which includes a feeding section 1, a drying section 2, an enthalpy-increasing combustion section 3, and a stable combustion section 4 which are sequentially connected along the movement direction of the material. The temperature of the material in the drying section 2, the enthalpy-increasing combustion section 3, and the stable combustion section 4 increases gradually. A material guiding mechanism is provided in the cylinder 15 of the drying section 2, the enthalpy-increasing combustion section 3, and the stable combustion section 4, and the stable combustion section 4 is provided with a burner 41; a heat-insulating material guiding mechanism 13 is also provided between the stable combustion section 4 and the enthalpy-increasing combustion section 3, which is used to transport the material from the enthalpy-increasing combustion section 3 to the stable combustion section 4; a gas exhaust channel 11 is provided at the top of the feeding section 1; the high-temperature flue gas released by the combustion of the material in the stable combustion section 4 moves toward each other in the cylinder 15 and performs convection heat exchange, and is finally discharged through the gas exhaust channel 11; it also includes a waste heat steam generating section 14 for transporting the high-temperature flue gas in the stable combustion section 4 to the enthalpy-increasing combustion section 3.

[0044] Optionally, after the drying section 2, the material temperature rises to above 80°C; after the enthalpy-increasing combustion section 3, the material temperature rises to above 120°C; the temperature of the material burning in the stable combustion section 4 is 700-950°C.

[0045] In the split rotary kiln of the present invention, the feeding section 1 conveys the material to the drying section 2 through a spiral device or other sealable device, preferably a spiral feeder 12. The gas exhaust channel 11 at the top of the feeding section 1 is used for the discharge of heat exchange exhaust gas. The material moves under the action of the spiral feeder 12 and simultaneously performs convection heat exchange with the high-temperature flue gas. As the cylinder 15 rotates, it is conveyed to the bottom wall of the cylinder 15 of the drying section 2; the material located in the drying section 2 moves and performs convection heat exchange with the high-temperature flue gas under the action of the material guiding mechanism and the rotation of the cylinder 15. The free water and part of the crystallized water of the material are diluted by the high-temperature flue gas and carried to the gas exhaust channel 11 and then discharged to the exhaust gas treatment system outside the split rotary kiln. After passing through the drying section 2, the temperature of the material itself rises to above 80°C; the material enters the enthalpy-increasing combustion section 3 and is rotated by the material guiding mechanism and the cylinder 15. Under the action of the material, the material moves and conducts convection heat exchange with the high-temperature flue gas. After passing through the enthalpy-increasing combustion section 3, the material's own enthalpy value is effectively improved, and its own temperature rises to above 120°C, close to the combustion point. Some ultra-fine materials may have been ignited, but only appear in the form of sparks, and no large-scale ignition occurs. When the material moves with the rotation of the cylinder 15 to the tail end of the enthalpy-increasing combustion section 3 close to the stable combustion section 4, some large-particle materials begin to burn and release heat energy into the space inside the cylinder; the material in the stable combustion section 4 moves under the action of the material guiding mechanism and the rotation of the cylinder 15. Under the action of the burner 41, the material enters a stable combustion state and continuously releases heat, and is mixed with the supplementary air for heat exchange to produce high-temperature flue gas. The high-temperature flue gas enters the enthalpy-increasing combustion section 3, the drying section 2, and the feeding section 1 through the waste heat steam generating section 14, and then enters the exhaust gas emission system through the gas exhaust channel 11.

[0046] Among them, the high-temperature resistant heat-insulating material guiding mechanism 13 can ensure that the temperature of the material will not drop significantly when it is introduced from the previous section (enthalpy increase combustion section 3) to the next section (stable combustion section 4), and the temperature drop is guaranteed to be no more than 50°C.

[0047] Optionally, the combustion stabilization section 4 is further provided with a centrifugal air blower 42, which includes a plurality of high-pressure air outlets 43 arranged at intervals. The air outlet direction of the high-pressure air outlet 43 is centrifugally arranged, and the high-pressure air outlet 43 is connected to the centrifugal air blower 42 through a high-pressure air supply channel 45. The air outlet direction of the high-pressure air outlet 43 is relative to the centrifugal end of the cylinder 15, and the specifications are distributed to the pre-retention space of the material. The high-pressure air outlet 43 is pressurized. When the air enters the combustion stabilization section 4 space through the high-pressure air outlet 43, it first contacts the inner wall of the cylinder 15 of the combustion stabilization section 4, and then changes direction to the centripetal end and carries part of the burning material to float, thereby blowing the material away and vacating it, which helps to increase the movement time of the material in the three-dimensional space of the cylinder 15 and the contact efficiency with oxygen, and ensure that the material and the oxygen-supplying air are fully mixed and fully burned.

[0048] The adoption of the above technical solution has the following technical effects: it ensures that the material can fully contact with the oxygen supply gas to the maximum extent and maintain its own full combustion; by adjusting the air supply direction of the high-pressure air outlet 43, the inner wall temperature of the cylinder 15 in the stable combustion section 4 space can be effectively reduced, effectively protecting the mechanical cylinder; the combustion material can be physically broken up and floated, ensuring that the combustion material performs reciprocating motion in the three-dimensional space, effectively avoiding the phenomenon of sticking and clumping due to excessive local temperature.

[0049] The high-pressure air outlets 43 are arranged in an orderly manner in the material pre-residence space, and their distribution density is related to the retention amount of the material in the pre-residence space. When the retention amount of the material is relatively large, the distribution density of the high-pressure air outlets 43 is large. When the retention amount of the material is small, the distribution density of the high-pressure air outlets 43 is relatively reduced.

[0050] The air pressure and air volume in each air supply channel 45 are controlled separately to ensure that the air volume can meet the air volume required for material combustion and the amount of air blown away and floated, while also controlling the heat carried away by the intake air to be absolutely less than the heat released by the combustion of the material in the stable combustion section 4.

[0051] Optionally, the material guide mechanism includes multiple guide plates 5, which are removably mounted on the inner wall of the cylinder 15 and arranged in a spiral pattern. The guide plates 5 are installed at a predetermined angle to the horizontal, ensuring sufficient heat exchange between the lifted material and the high-temperature flue gas. The guide plates 5 also cooperate with the rotation of the cylinder to promote material movement. The guide plates 5 are preferably wedge-shaped, with their outer walls coated with refractory material to withstand the high-temperature environment within the cylinder. The guide plates 5 are arranged in a spiral pattern on the inner wall of the cylinder in an inlaid manner to ensure material forward movement and sufficient convective heat exchange with the high-temperature flue gas.

[0052] Optionally, the guide plate 5 of the enthalpy-increasing combustion section 3 is a reciprocating structure to ensure the residence time of the material in the enthalpy-increasing combustion section 3, so that the material can have enough time to conduct convective heat exchange with the high-temperature flue gas in the three-dimensional space. Specifically, the installation direction of the guide plate 5 of the enthalpy-increasing combustion section 3 is forward and reverse. Among them, the guide plate 5 with the forward installation direction is a forward feeding guide plate, and the angle between it and the axis of the cylinder 15 is a positive angle, preferably 10-15 degrees, so as to achieve the function of conveying the material forward; the guide plate 5 with the reverse installation direction is installed at a negative angle with the axis of the cylinder 15, preferably -5 to -8 degrees, to return the material in the reverse short distance (backward return) to achieve the purpose of reciprocating motion of the material.

[0053] Optionally, the feeding section 1, the drying section 2 and the enthalpy-increasing combustion section 3 are arranged in series in the horizontal direction, the heat-insulating material guiding mechanism 13 is extended in the vertical direction, and the stable combustion section 4 and the enthalpy-increasing combustion section 3 are separated to adapt to different site requirements.

[0054] The split rotary kiln decomposes the rotary kiln into multiple functional units, namely, a separate drying section 2, an enthalpy-increasing combustion section 3, a stable combustion section 4 and a waste heat steam generating section 14, which is conducive to controlling different working conditions for different material states. Compared with the traditional integrated rotary kiln, it is more flexible in operation, which is conducive to improving the stability of system operation and improving production efficiency.

[0055] Optionally, it also includes a discharge slag cooling mechanism 10, one end of which is connected to the end of the stable combustion section 4 away from the heat preservation material guiding mechanism 13, and the other end is connected to the waste heat steam generating section 14. The temperature of the material discharged from the stable combustion section 4 is 400-600°C. After heat exchange through the heat exchange module 18 in the discharge slag cooling mechanism 10, the sensible heat of the material slag can be effectively utilized, and then the slag is discharged through the slag discharge port 6, and the high-temperature flue gas enters the waste heat steam generating section 14.

[0056] Optionally, the split rotary kiln can add a waste heat utilization system in the enthalpy-increasing combustion section 3, and the medium-temperature flue gas after waste heat utilization is used as the drying heat source of the drying section 2, realizing the cascade utilization of the high-temperature flue gas heat source and achieving the purpose of energy saving and consumption reduction.

[0057] Optionally, the diameters of the cylinders 15 of the drying section 2 and the enthalpy increase combustion section 3 are the same and are both smaller than the diameter of the cylinder 15 of the stable combustion section 4. The radial reduction ensures the realization of the gradient temperature difference between the enthalpy increase combustion section 3 and the stable combustion section 4, and an annular refractory baffle is circumferentially provided inside the cylinder 15 between the drying section 2 and the enthalpy increase combustion section 3 to ensure the realization of the gradient temperature difference between the drying section 2 and the enthalpy increase combustion section 3.

[0058] Optionally, a supporting wheel 8 and a transmission gear 9 are provided on the outer wall of the cylinder 15 for driving the rotation of the rotary kiln cylinder 15 .

[0059] Optionally, a refractory layer 16 is provided on the outer wall of the cylinder 15 to ensure that the split rotary kiln has good refractory performance.

[0060] Optionally, a thermocouple 7 is provided on the cylinder wall for monitoring the internal temperature of the cylinder 15 .

[0061] Optionally, a stable combustion partition mechanism 44 is provided on the cylinder wall of the stable combustion section 4 to prevent the high-temperature flue gas in the stable combustion section 4 from leaking or conducting heat to the environment, ensuring that the high-temperature flue gas moves to the end of the gas discharge channel 11 while ensuring the ambient temperature in the stable combustion section 4.

[0062] In the split-type rotary kiln of this invention, the oxygen blower for burner 41 is a normal-pressure blower, and the amount of oxygen supplied is controlled during the injection process to prevent the sudden influx of large amounts of gas into a particular annular space. This prevents the rapid expansion of the incoming gas at high temperatures, causing dramatic pressure fluctuations in that annular space and affecting the stability of the entire combustion system. Note that in this system, if the temperature rises rapidly and uncontrollably, steam or water can be directly injected into the oxygen supply system and flue gas recirculation system to directly cool the rotary kiln cylinder.

[0063] In the split rotary kiln of the present invention, under controlled combustion, the temperature of the cavity space of the entire stable combustion section 4 from the feed end to the discharge end is controlled to 700-950°C, preferably around 900°C, which not only ensures the safety of the equipment and exhaust gas control, but also ensures that the entire stable combustion section 4 system can continuously generate high-temperature flue gas to create benefits.

[0064] The split rotary kiln of the present invention can also arrange the material enthalpy-increasing combustion section 3 and the drying section 2 separately, which can ensure both the integrity and flexibility of the process.

[0065] The material guiding method of the split rotary kiln of the present invention is to guide the material with a wedge-shaped material guiding plate, or the drum of the rotary kiln can be arranged at an angle, that is, the drum is placed at a certain angle to the horizontal direction, and / or a directional material guiding method is used to increase the material's own gravity sliding.

[0066] The split rotary kiln of the present invention does not require grinding of materials. The feed and discharge particle sizes are related to the processing objectives and can be simply processed. Note: The particle size of the material mainly affects the combustion efficiency. As long as the particle size can meet the combustion efficiency requirements, no special processing of the material particle size is required.

[0067] The split rotary kiln of the present invention adopts a unique composite oxygen supply method, that is, composite oxygen supply through the burner 41 and the centrifugal blower 42, which solves the air supply problem of the traditional process and enables the material to be fully combined with the oxygen required for combustion in the three-dimensional space, ensuring sufficient combustion while also allowing the heat in the combustion space to be released in time to maintain the stability of the spatial heat load.

[0068] The material processed by the split rotary kiln of the present invention is a flame-retardant material represented by gasification furnace slag, with a moisture content of 30-50%.

[0069] The method for burning materials using the split rotary kiln of the present invention comprises the following steps:

[0070] (1) Feeding: The material is transported from the feeding section 1 to the drying section 2;

[0071] (2) Water evaporation: The material is in the drying section 2. Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer. The free water and part of the crystallized water of the material are carried by the high-temperature flue gas to the gas exhaust channel 11;

[0072] (3) Preheating enthalpy increase: The material is located in the enthalpy increase combustion section 3. Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer, the material's own enthalpy value increases, and part of the material has been ignited, undergoing surface combustion or existing in the state of sparks;

[0073] (4) Stable combustion: The material is in the stable combustion section 4. After the material is mixed with the gas, it enters a stable combustion state and continuously releases heat. The heat is mixed with the gas and forms high-temperature flue gas after heat exchange.

[0074] The split rotary kiln of the present invention can comprehensively treat vaporized slag with a moisture content of 30-50%, increase the value of the high-water content vaporized slag material to be gasified (preheating enthalpy increase) and the ignition process, and increase the stable combustion space, providing sufficient oxygen for the combustible material and ensuring its stable combustion. In the process of treating the combustible material, a convection heat exchange process is adopted in which high-temperature flue gas is transferred to the feed end to exchange heat with the newly fed material, thereby improving the heat exchange efficiency of the material to be burned. In this process, the increase in water evaporation and preheating enthalpy increase ensures that the material in the stable combustion section can be fully and stably burned. The process of the present invention is easy to implement and low in cost.

[0075] 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, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A split rotary kiln, comprising a cylinder, characterized in that: The cylinder includes a feeding section, a drying section, an enthalpy-increasing combustion section, and a stable combustion section which are connected and arranged along the movement direction of the material. The temperature of the material in the drying section, the enthalpy-increasing combustion section, and the stable combustion section increases gradually. The drying section, the enthalpy-increasing combustion section, and the stable combustion section are all provided with a material guiding mechanism, and the stable combustion section is provided with a burner; A heat-insulating material guiding mechanism is further provided between the combustion stabilization section and the enthalpy-increasing combustion section; A gas discharge channel is provided at the top of the feeding section; The high-temperature flue gas released by the combustion of the material in the stable combustion section moves toward the material in the cylinder; It also includes a waste heat steam generating section for conveying the high temperature flue gas from the stable combustion section to the enthalpy-increasing combustion section; The stable combustion section is further provided with a centrifugal air blower; the centrifugal air blower comprises a plurality of high-pressure air outlets arranged at intervals, and the air outlet direction of the high-pressure air outlet is centrifugally arranged; The material guiding mechanism of the enthalpy increasing combustion section is a reciprocating material guiding mechanism, and the material guiding mechanism includes a plurality of material guiding plates. The installation directions of the material guiding plates of the enthalpy increasing combustion section are forward and reverse directions. Among them, the angle between the material guiding plate with the forward installation direction and the axis of the cylinder is a positive angle, and the installation angle of the material guiding plate with the reverse installation direction is a negative angle with the axis of the cylinder.

2. The split rotary kiln according to claim 1, characterized in that: After passing through the drying section, the material temperature rises to above 80°C; after passing through the enthalpy-increasing combustion section, the material temperature rises to above 120°C; the temperature of the material burning in the stable combustion section is 700-950°C.

3. The split rotary kiln according to claim 1, characterized in that: The material guiding mechanism includes a plurality of material guiding plates, which are arranged on the inner wall of the cylinder and arranged in a spiral shape.

4. The split rotary kiln according to claim 1, characterized in that: The feeding section, the drying section and the enthalpy-increasing combustion section are sequentially arranged in series along the horizontal direction, and the heat-insulating material guiding mechanism is extended along the vertical direction.

5. The split rotary kiln according to claim 1, characterized in that: It also includes a discharge and cooling slag mechanism, one end of which is connected to an end of the stable combustion section away from the heat preservation and material guiding mechanism, and the other end is connected to the waste heat steam generating section.

6. The split rotary kiln according to claim 1, characterized in that: The temperature of the material discharged from the stable combustion zone is 400-600℃.

7. A method for burning materials, characterized in that: The split rotary kiln according to any one of claims 1 to 6 comprises the following steps: (1) Feeding: The material is transported to the drying section through the feeding section; (2) Water evaporation: Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer, and the free water and part of the crystallized water in the material are carried to the gas discharge channel by the high-temperature flue gas; (3) Preheating enthalpy increase: Under the action of the material guide mechanism, the material and the high-temperature flue gas undergo sufficient convection heat transfer, the material's own enthalpy value increases, and part of the material has been ignited, undergoing surface combustion or existing in the state of sparks; (4) Stable combustion: After the material and gas are mixed, they enter a stable combustion state and continuously release heat. The heat mixes with the gas and forms high-temperature flue gas after heat exchange.

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