Coal processing pyrolysis furnace

Abstract

The application relates to the technical field of coal processing, and particularly discloses a pyrolysis furnace for coal processing, which comprises an axially segmented cylindrical furnace body and a rotating airflow injection assembly; the axially segmented cylindrical furnace body is sequentially divided into a preheating section, first to fourth pyrolysis sections and a cooling section along the axial direction, and each section is respectively provided with an independent temperature control device; the furnace body as a whole is designed as a circular truncated cone from the preheating section to the cooling section, the preheating section has a small diameter, and the cooling section has a large diameter; each section has a height difference; the rotating airflow injection assembly sprays airflow with different flow rates through uniformly distributed nozzles, so that the coal material continuously turns over in the falling process; and the head of the preheating section is provided with a lean-oxygen burner. The patent aims to solve the problems that the existing pyrolysis furnace does not have the functions of segmented gradient temperature control, dynamic material separation and source reduction design.

Description

Technical Field

[0001] This utility model relates to the field of coal processing technology, and in particular to a pyrolysis furnace for coal processing. Background Technology

[0002] A coal pyrolysis furnace is a device for heating coal. Through pyrolysis, coal is decomposed into three main products: semi-coke, coal tar, and coal gas. It employs indirect heating to achieve graded conversion and utilization of the coal, and the products can be used as chemical raw materials.

[0003] Existing coal pyrolysis equipment suffers from low pyrolysis efficiency, insufficient product separation, and inadequate environmental protection. For example, although the biomass pyrolysis rotary kiln disclosed in CN201530810U achieves continuous production through a three-stage structure of preheating, pyrolysis, and cooling sections, its pyrolysis section uses a single temperature control, which is difficult to adapt to the gradient temperature rise requirements of the coal pyrolysis process. During coal pyrolysis, the release of tar and coal gas is sensitive to temperature changes. If the entire pyrolysis section uses only a fixed temperature, the released volatile components, such as tar vapor and coal gas, will undergo further cracking reactions in a high-temperature environment, leading to further breakage of their molecular structure and the generation of smaller molecules such as methane and hydrogen, thereby reducing the yield and quality of tar.

[0004] In addition, the equipment relies on the rotation of the furnace body to move the material and only relies on gravity to turn the material over. The turning efficiency is low and there is uneven heating when the material clumps. This leads to the obstruction of the diffusion of pyrolysis gas from inside the coal particles and low separation efficiency of semi-coke and volatile components.

[0005] Meanwhile, existing pyrolysis furnaces mostly use conventional burners in their preheating sections, and the high-temperature, oxygen-rich environment easily generates nitrogen oxides, causing environmental pollution. Although emissions can be reduced through exhaust gas treatment, this does not control pollutant generation at the source.

[0006] In summary, there is an urgent need in the existing technology for a pyrolysis furnace that can achieve segmented gradient temperature control, dynamic material separation, and source emission reduction design. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a pyrolysis furnace for coal processing, which solves the problems of existing pyrolysis furnaces lacking segmented gradient temperature control capabilities, dynamic material separation, and source emission reduction design.

[0008] To solve the above problems, the technical solution adopted by this utility model is: a pyrolysis furnace for coal processing, including an axially segmented cylindrical furnace body and a rotating airflow injection assembly; the axially segmented cylindrical furnace body is divided into a preheating section, a first to fourth pyrolysis section and a cooling section along the axial direction, and each section is equipped with an independent temperature control device; from the preheating section to the cooling section, the furnace body is designed as a frustum, and the diameter gradually increases from the preheating section to the cooling section to create a height difference between the sections; the rotating airflow injection assembly sprays rotating airflow flowing along the circumference of the furnace wall through nozzles evenly distributed along the furnace wall, causing the coal to continuously tumble during its descent; an oxygen-deficient burner is installed at the head of the preheating section.

[0009] Compared with existing technologies, the beneficial effects of this solution are: 1. The axially segmented cylindrical furnace body and the rotating airflow injection components work together to ensure that the coal reaches the appropriate temperature at different stages, promoting the pyrolysis reaction and increasing the tar and gas yields; the rotating airflow can turn the coal over and achieve directional separation, reducing the possibility of secondary cracking and coking; 2. The furnace body structure is designed in a frustum shape, making the material movement more orderly and improving the continuity and efficiency of pyrolysis; 3. The airflow injection keeps the fuel turning over, ensuring uniform pyrolysis and simultaneously optimizing tar vapor separation, improving tar purity and semi-coke quality; 4. The oxygen-deficient burner is directly integrated into the preheating section, reducing nitrogen oxide emissions and making it more environmentally friendly.

[0010] Furthermore, a feed inlet is provided at the upper part of the preheating section.

[0011] Furthermore, a discharge port is provided at the bottom of the cooling section.

[0012] Furthermore, the oxygen-deficient burner consists of a burner head, a fuel supply pipe, and an air supply pipe. The burner head is made of a high-temperature resistant alloy and is conical in shape. The fuel supply pipe and the air supply pipe are connected to the burner head.

[0013] Furthermore, the temperature control device also includes a heating device and a cooling device. The cooling section uses cooling water pipes as the cooling device, and the cooling water pipes are wrapped around the outside of the furnace body.

[0014] Furthermore, the heating device is an electric heating wire made of nickel-chromium alloy, which is wound around the inner wall of the furnace body.

[0015] Furthermore, the heating device is a microwave heating device, with multiple microwave emitting units arranged in a ring on the outer side of the furnace wall in the pyrolysis section, uniformly covering the axial length of the pyrolysis area, and a microwave reflective layer embedded in the inner wall of the furnace cavity.

[0016] Furthermore, the rotating airflow injection assembly is evenly distributed along the circumference of the furnace wall. The rotating airflow injection assembly includes at least twelve sets of directional nozzles. The nozzles are truncated cone-shaped, and truncated cone-shaped holes are provided on the side of the nozzles. Each nozzle is connected to the air source through a pipe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the cylindrical furnace body structure of this application.

[0018] Figure 2 This is a schematic diagram of the rotating airflow jet assembly of this application.

[0019] Figure 3 This is a schematic diagram of the nozzle structure of this application.

[0020] The reference numerals in the accompanying drawings include: furnace body 1; preheating section 16; first pyrolysis section 11; second pyrolysis section 12; third pyrolysis section 13; fourth pyrolysis section 14; cooling section 15; injection assembly 2; nozzle 21; frustum-shaped hole 211; temperature control device 3; oxygen-deficient burner 4; feed inlet 5; and discharge outlet 6. Detailed Implementation

[0021] The following detailed description illustrates the specific implementation method: Example 1 As attached Figures 1 to 2 As shown: A pyrolysis furnace for coal processing includes an axially segmented cylindrical furnace body 1 and a rotating airflow injection assembly 2. The axially segmented cylindrical furnace body 1 and the rotating airflow injection assembly 2 work together to ensure that the coal material receives appropriate temperatures at different stages, promoting the pyrolysis reaction. The appropriate temperature gradient ensures that tar and coal gas can be released more fully from the coal material, improving tar yield and coal gas yield. The rotating airflow can turn the coal material over and achieve directional separation, which helps the volatile gases generated by pyrolysis to diffuse more quickly from the inside of the coal particles, reducing the possibility of secondary cracking and coking.

[0022] Specifically, the axially segmented cylindrical furnace body 1 is sequentially divided into a preheating section 16, a first pyrolysis section 11, a second pyrolysis section 12, a third pyrolysis section 13, a fourth pyrolysis section 14, and a cooling section 15, each section equipped with an independent temperature control device 3. From the preheating section 16 to the cooling section 15, the furnace body 1 has an overall frustum-shaped design, with the preheating section 16 having a smaller diameter and the cooling section 15 having a larger diameter, and there is a height difference between the sections. This allows the coal to naturally move backward under gravity when the furnace body 1 rotates. The height difference between the sections prevents coal entering a later section from returning to the previous section. This design of the furnace body 1 acts like a special channel within which the coal moves and reacts in an orderly manner.

[0023] A lean-oxygen burner 4 is installed at the head of the preheating section 16. The lean-oxygen burner 4 consists of a burner head, a fuel supply pipe, and an air supply pipe. The burner head is made of a high-temperature resistant alloy to adapt to the high-temperature combustion environment. The fuel supply pipe and air supply pipe are connected to the burner head, and lean-oxygen combustion is achieved by adjusting the supply of fuel and air. The lean-oxygen combustion method can effectively suppress the formation of nitrogen oxides by reducing the combustion temperature and oxygen concentration. A feed inlet 5 is provided at the top of the preheating section 16. The first to fourth pyrolysis sections 14 are set with progressively increasing pyrolysis temperatures along the axial direction, namely 650℃, 750℃, 850℃, and 900℃, respectively. Each pyrolysis section is equipped with an independent temperature control device 3, such as using an electric heating wire. The electric heating wire is made of nickel-chromium alloy, which has good high-temperature resistance and resistance characteristics. It is wound around the inner wall of the furnace body 1 and generates heat by energizing it. Alternatively, microwave heating can be used for temperature control. During microwave heating, multiple microwave emitting units are arranged in a ring on the outer side of the furnace wall of the pyrolysis section, uniformly covering the axial length of the pyrolysis area. Each microwave transmitting unit consists of a magnetron and a waveguide transmission system. The magnetron power is configured in stages according to the temperature rise requirements of the pyrolysis section, and the microwaves are directionally transmitted to the furnace cavity via the waveguide. A microwave reflective layer is embedded in the inner wall of the furnace cavity to ensure uniform energy distribution. The cooling section 15 is equipped with a cooling device, such as cooling water pipes, which surround the outside of the furnace body 1. The circulating cooling water removes heat, thus cooling the coke. When the coke temperature drops to 200°C, it is discharged through the discharge port 6 at the bottom of the cooling section 15.

[0024] Specifically, the rotating airflow injection assembly 2 is arranged around the furnace wall. The rotating airflow injection assembly 2 includes at least twelve sets of directional nozzles 21, which are made of silicon carbide and possess excellent high-temperature resistance. (See attached image.) Figure 3 As shown, the nozzle 21 is shaped like a frustum. The airflow enters from the bottom of the frustum and exits from the top of the frustum. The side of the frustum nozzle 21 is also provided with frustum-shaped holes 211. The holes on the inner side are large and the holes on the outer side are small. This design can increase the pressure of the jet airflow and prevent the side of the nozzle 21 from being blocked by material.

[0025] The rotating airflow injection assembly 2 is uniformly distributed along the circumference of the furnace wall. The airflow direction of the nozzles 21 is all pointing towards the center of the furnace body 1, and the airflow velocity generated by the injection assembly 2 decreases along the rotation direction of the furnace body 1, from 0.8 m / s to 0.3 m / s. Each nozzle 21 is connected to a gas source via a pipe. The gas source can be compressed air or other gases. The speed and intensity of the airflow are controlled by adjusting the pressure and flow rate of the gas source. The combination logic of the rotating airflow injection assembly 2 is to spray airflow through the uniformly distributed nozzles 21, causing the coal to continuously tumble during its descent, promoting full contact between the coal and the pyrolysis environment, and achieving directional separation of tar vapor and semi-coke.

[0026] The working principle is as follows: The pyrolysis furnace in this embodiment uses axial segmented gradient heating and independent temperature control to ensure that the coal reaches appropriate temperatures at different stages, promoting the pyrolysis reaction and increasing tar yield. The rotating airflow injection assembly 2 continuously tumbles the coal, achieving directional separation of tar vapor and semi-coke, reducing secondary reaction coking. The oxygen-deficient burner 4 reduces nitrogen oxide emissions, lowering environmental pollution. Compared to traditional pyrolysis furnaces, this represents a significant improvement and enhancement, increasing the efficiency and environmental friendliness of coal pyrolysis.

[0027] Feeding process: Coal enters the pyrolysis furnace from the feed inlet 5 at the top of the preheating section 16.

[0028] Preheating and shifting process: The oxygen-deficient burner 4 at the head of the preheating section 16 operates to dry and preheat the coal.

[0029] Gradient pyrolysis process: Coal passes through four axially segmented pyrolysis stages 14 sequentially: Stage 11, temperature controlled at approximately 650℃, initiates pyrolysis; Stage 2, temperature rises to approximately 750℃, intensifying the pyrolysis reaction; Stage 3, temperature further rises to approximately 850℃, achieving deep pyrolysis; Stage 4, temperature reaches approximately 900℃, completing the pyrolysis reaction. Each stage is precisely controlled by independent heating elements. From preheating stage 16 to stage 4, the rotating airflow injection assembly 2 within the furnace body 1 continuously injects rotating airflow into the furnace. The airflow velocity decreases from 0.8 m / s to 0.3 m / s along the rotation direction of the furnace body 1. The airflow serves to continuously tumble the coal, increasing its contact with the thermal environment; promote the rapid diffusion and release of volatiles such as tar vapor and coal gas generated during pyrolysis from within the coal particles; and achieve directional separation of tar vapor and semi-coke, reducing secondary cracking and coking.

[0030] Cooling process: The pyrolyzed coke enters the cooling section 15. The cooling device outside the cooling section 15 circulates cooling water to remove the heat from the coke and reduce its temperature to about 200°C.

[0031] Discharge stage: The cooled coke is discharged from the pyrolysis furnace through the discharge port 6 at the bottom of the cooling section 15.

[0032] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A pyrolysis furnace for coal processing, comprising an axially segmented cylindrical furnace body and a rotating gas jet injection assembly, characterized in that: The axially segmented cylindrical furnace body is divided into a preheating section, the first to fourth pyrolysis sections, and a cooling section along the axial direction. Each section is equipped with an independent temperature control device. From the preheating section to the cooling section, the furnace body is designed as a frustum, with a smaller diameter in the preheating section and a larger diameter in the cooling section. There is a height difference between the sections. The rotating airflow injection assembly injects rotating airflow through evenly distributed nozzles, causing the coal to continuously tumble during its descent. An oxygen-deficient burner is installed at the head of the preheating section.

2. The pyrolysis furnace for coal processing according to claim 1, characterized in that: The preheating section is equipped with a feed inlet at the top.

3. The pyrolysis furnace for coal processing according to claim 1, characterized in that: The cooling section has a discharge port at its bottom.

4. The pyrolysis furnace for coal processing according to claim 1, characterized in that: The oxygen-deficient burner consists of a burner head, a fuel supply pipe, and an air supply pipe. The burner head is made of a high-temperature resistant alloy and is conical in shape. The fuel supply pipe and the air supply pipe are connected to the burner head.

5. A pyrolysis furnace for coal processing according to claim 1, characterized in that: The temperature control device also includes a heating device and a cooling device. The cooling section uses cooling water pipes as the cooling device, and the cooling water pipes are wrapped around the outside of the furnace body.

6. A pyrolysis furnace for coal processing according to claim 5, characterized in that: The heating device is an electric heating wire made of nickel-chromium alloy, which is wound around the inner wall of the furnace.

7. A pyrolysis furnace for coal processing according to claim 5, characterized in that: The heating device is a microwave heating device, with multiple microwave emitting units arranged in a ring on the outer side of the furnace wall in the pyrolysis section, uniformly covering the axial length of the pyrolysis area, and a microwave reflective layer embedded in the inner wall of the furnace cavity.

8. A pyrolysis furnace for coal processing according to claim 1, characterized in that: The rotating airflow injection assembly is evenly distributed along the circumference of the furnace wall. The rotating airflow injection assembly includes at least twelve sets of directional nozzles. The nozzles are truncated cone-shaped and have truncated cone-shaped holes on their sides. Each nozzle is connected to the air source through a pipe.

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