Heat pipe type baking reactor and solid waste baking method thereof

Abstract

The invention discloses a heat pipe type baking reactor and a solid waste baking method thereof.The main body of the heat pipe type baking reactor is a heat pipe, a material chamber, a preheating chamber and a gas channel, the heat pipe comprises an evaporation section, a heat insulation section, a condensation section and a working medium, and the material chamber is composed of fins, a net sleeve, a jacket, a gas distribution plate and an end socket; the preheating chamber is composed of a gas distribution plate, a jacket and a flange end cover, a gas inlet is formed in the lower end of the flange end cover, a gas outlet is formed in the upper end of the end socket, and exhaust holes are formed in the fins. When the heat pipe type baking reactor is used for baking solid waste, materials are filled in the material chamber, a heat source is applied to the evaporation section of the heat pipe, and the temperature field of the materials is uniform by virtue of the characteristics of fast heat transfer and good temperature uniformity of the heat pipe; moreover, baking moisture can be taken away, and the quality of baked products and the energy utilization efficiency can be improved.

Description

[0001] The present invention relates to the technical field of solid waste baking pretreatment, and in particular to a heat pipe baking reactor and a solid waste baking method thereof. Background Art

[0002] The disposal and resource utilization of solid waste (referred to as "solid waste") through thermochemical conversion methods such as pyrolysis or gasification is a research hotspot in the field of energy and environment today, and is of great significance to improving China's energy structure and ecological environment. However, due to the high moisture content and low energy density of solid waste, it needs to be pretreated before deep thermochemical treatment. Baking pretreatment technology is a thermochemical pretreatment method carried out in a temperature range of 200~400℃ in a low-oxygen or oxygen-free atmosphere. After baking treatment, solid waste obtains a solid product with low moisture content, high energy density, easy to crush and hydrophobic.

[0003] The Chinese invention patent with patent number 201410001428.8 provides a biomass roasting method, in which the reactor is a double-layer jacket structure, and the mixed flue gas at 350-400°C is input into the jacket outside the inner cavity of the roasting reactor from the jacket air inlet on the same side as the feed port of the roasting reactor, and at the same time, the roasting hot air flow is transported from the gas inlet at the discharge port of the roasting reactor to the inner cavity of the roasting reactor, so that the roasting hot air flow flows in the opposite direction to the conveying direction of the biomass raw material, and the mixed hot air flow formed in the inner cavity of the roasting reactor is discharged from the gas outlet at the feed port of the roasting reactor. The biomass raw material and the mixed flue gas are indirectly transferred to heat in the same direction, and directly convectively transferred to heat in the opposite direction to the roasting hot air flow to perform a roasting reaction, and roasted biomass is obtained after the roasting reaction. The Chinese invention patent with the patent number 201410183062.0 provides a biomass baking method, which uses flue gas for external indirect heating and internal indirect heating of the biomass to be baked, and the flue gas for external indirect heating and the biomass to be baked flow in countercurrent, and the flue gas for internal indirect heating and the biomass to be baked flow in parallel. The Chinese invention patent with the patent number 202123455704.2 provides a high-temperature baking treatment device for oil-containing sludge, which heats the sludge by continuous stirring and turning, and the exhaust flow channel can discharge the water-oil mixed steam evaporated after high-temperature baking from the baking chamber. Whether it is direct or indirect heating baking technology, the main problems currently existing are uneven heating of solid waste, unstable product quality, low semi-coke generation and heat transfer efficiency, which greatly reduces the yield of baked solid waste and the quality stability of the obtained baked biomass is poor. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of uneven bed temperature caused by excessive material accumulation during solid waste baking pretreatment, and propose a heat pipe baking reactor and a solid waste baking pretreatment method thereof to improve the bed temperature uniformity and energy utilization efficiency.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a heat pipe type baking reactor, wherein the reactor body comprises a heat pipe, a material chamber, a preheating chamber and a gas channel, wherein the heat pipe comprises an evaporation section, an insulation section and a condensation section, and the space inside the heat pipe is partially filled with a medium-temperature working medium, and the material chamber is composed of fins, a mesh sleeve, a jacket, a gas distribution plate and a head, wherein the fins are welded to the outer wall of the condensation section, and exhaust holes are provided on the surface, the mesh sleeve is tightly fitted to the fins, the gas distribution plate is connected to the lower end of the fins, the jacket is coaxially placed with the condensation section, and is sleeved on the periphery of the mesh sleeve, and the upper and lower ends are respectively sealed by a head and a flange end cover, a gas outlet is provided at the upper end of the head, the flange end cover is connected to the outer wall of the condensation section and the lower end of the fins, and a gas inlet is provided at the lower end of the flange end cover, the preheating chamber is composed of a gas distribution plate, a jacket and a flange end cover, and the gas channel is composed of fins and a jacket.

[0006] Furthermore, the heat pipe has a metal shell, the material of which is one of stainless steel, aluminum or carbon steel, with an outer diameter of 8~100mm, a wall thickness of 1~5mm, a length of 0.1~10m, and a length ratio of the condensation section to the evaporation section of 1~20:1.

[0007] Furthermore, the medium-temperature working fluid is one of thermal conductivity, naphthalene, sulfur and mercury, the volume fraction of the medium-temperature working fluid in the internal space of the heat pipe is 5%~40%, and the temperature range is 200~400℃.

[0008] Furthermore, the fins are made of metal, such as stainless steel, aluminum or carbon steel, with a width of 5 to 200 mm, a thickness of 1 to 5 mm, a height of 0.1 to 5 m, and the exhaust holes on the surface are round or square with a diameter of 1 to 10 mm.

[0009] Furthermore, the mesh sleeve is one of stainless steel, nickel or ceramic, and can be in the shape of a wire mesh, a woven mesh, foam metal or foam ceramic, with a diameter of 15-300 mm, a thickness of 1-5 mm, and a mesh size of 50-150.

[0010] Furthermore, the jacket is made of stainless steel or carbon steel, has a diameter of 15-300 mm, a thickness of 1-5 mm, and is placed coaxially with the heat pipe.

[0011] Furthermore, the jacket is arranged on the periphery of the mesh sleeve, leaving an annular gap of 5 to 10 mm.

[0012] Furthermore, the gas distribution plate is made of stainless steel or carbon steel, with a diameter of 15-300 mm and a thickness of 1-5 mm.

[0013] Furthermore, the shape of the head is one of spherical, conical, elliptical or flat cover, made of stainless steel or carbon steel, with a diameter of 15~300mm and a thickness of 1~5mm.

[0014] Furthermore, the material chamber is a space composed of fins, the outer wall of the condensation section, the mesh sleeve and the gas distribution plate, and the material filling height is 0.1~9m.

[0015] Furthermore, the preheating chamber is a space composed of the gas distribution plate, the outer wall of the condensation section, the jacket and the flange end cover, and has a height of 50-200 mm.

[0016] Furthermore, the gas channel is an annular space composed of fins and jackets, and the annular gap spacing is 2-20 mm.

[0017] On the other hand, the present invention also provides a heat pipe type baking reactor for solid waste baking pretreatment method, specifically including: when the baking reactor performs baking pretreatment on solid waste material, the material is loaded into the material chamber from the upper end of the jacket, the jacket and the head are sealed and connected by a flange, the heat pipe insulation section and the jacket are both insulated, and the gas inlet at the lower end of the flange end cover is introduced into the purge gas to create a baking atmosphere, and a heat source is applied to the evaporation section of the heat pipe. After the heat pipe is started, the internal working fluid is in a state of axial uniform temperature under the action of the vaporization / condensation phase change circulation flow. In addition, after the purge gas reaches the baking temperature in the preheating chamber, it enters the gas channel through the gas distribution plate, and the material is baked under the conditions of indirect heat conduction of the fins and convective heat exchange of the purge gas. At the same time, the baking gas is carried away by the purge gas through the exhaust holes on the fins and the gas channel, and the material is quickly and evenly baked, avoiding the uneven temperature distribution caused by the accumulation of materials during the baking process, resulting in uneven baking products, and low energy utilization efficiency.

[0018] Furthermore, the solid waste material may be a mixture of one or more solid wastes such as sludge, garbage, plastic and biomass.

[0019] Furthermore, the heat source can be any one of solar energy, waste heat flue gas and a tubular furnace.

[0020] The beneficial effects of the present invention are as follows: by utilizing the high heat transfer efficiency and good temperature uniformity of the heat pipe, the temperature of the entire material bed is made uniform, the material stacking height can be further increased, the problem of uneven heating of solid waste raw materials in the reactor is solved, and the baking yield is greatly improved; an exhaust channel is arranged in the material chamber, which is conducive to the migration of moisture, while increasing the convection heat exchange capacity and improving energy utilization efficiency; in addition, the heat source is separated from the material chamber, and the input heat source can use waste heat flue gas or solar heat source, saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a heat pipe baking reactor of the present invention; Figure 2 AA cross-sectional view of a heat pipe baking reactor of the present invention The figure shows: 1. heat pipe; 2. evaporation section; 3. insulation section; 4. condensation section; 5. fins; 6. exhaust holes; 7. jacket; 8. head; 9. gas outlet; 10. gas channel; 10 (a), gas annular gap channel; 10 (b), fin gap channel; 11. mesh sleeve; 12. material chamber; 13. gas distribution plate; 14. preheating chamber; 15. flange end cover; 16. gas inlet; 17. medium-temperature working fluid.

Claims

1. A heat pipe baking reactor, characterized in that: The reactor body comprises a heat pipe (1), a material chamber (12), a preheating chamber (14) and a gas channel (10). The heat pipe (1) comprises an evaporation section (2), an insulation section (3) and a condensation section (4). The space inside the heat pipe (1) is filled with a medium-temperature working medium (17). The material chamber (12) comprises fins (5), a mesh sleeve (11), a jacket (7), a gas distribution plate (13) and a head (8). The fins (5) are welded to the outer wall of the condensation section (4) and have exhaust holes (6) on the surface. The mesh sleeve (11) is tightly fitted to the fins (5). The gas distribution plate (13) is The lower end of the fin (5) is connected, the jacket (7) is coaxially placed with the condensation section (4), and is sleeved on the outer periphery of the mesh sleeve (11), and the upper and lower ends are sealed by a head (8) and a flange end cover (15) respectively, a gas outlet (9) is provided at the upper end of the head (8), the flange end cover (15) is connected to the outer wall of the condensation section (4) and the lower end of the fin (5), and a gas inlet (16) is provided at the lower end of the flange end cover (15), the preheating chamber (14) is composed of a gas distribution plate (13), a jacket (7) and a flange end cover (15), and the gas channel (10) is composed of the fin (5) and the jacket (7).

2. A heat pipe baking reactor according to claim 1, characterized in that: The heat pipe (1) has a metal shell made of one of stainless steel, aluminum or carbon steel, an outer diameter of 8 to 100 mm, a wall thickness of 1 to 5 mm, a length of 0.1 to 10 m, and a length ratio of the condensation section to the evaporation section of 1 to 20:

1.

3. A heat pipe baking reactor according to claim 1, characterized in that: The medium-temperature working fluid (17) is one of thermal conductivity, naphthalene, sulfur and mercury. The volume fraction of the medium-temperature working fluid in the internal space of the heat pipe is 5% to 40%, and the temperature range is 200 to 400°C.

4. A heat pipe baking reactor according to claim 1, characterized in that: The fin (5) is made of metal, such as stainless steel, aluminum or carbon steel, with a width of 5 to 200 mm, a thickness of 1 to 5 mm and a height of 0.1 to 5 m. The exhaust holes (6) on the surface are in the shape of round holes or square holes with a diameter of 1 to 10 mm.

5. The heat pipe baking reactor according to claim 1, characterized in that: The mesh sleeve (11) is made of one of stainless steel, nickel or ceramic, and can be in the shape of a wire mesh, a woven mesh, foam metal or foam ceramic, with a diameter of 15-300 mm, a thickness of 1-5 mm, and a mesh size of 50-150.

6. The heat pipe baking reactor according to claim 1, characterized in that: The jacket (7) is made of stainless steel or carbon steel, has a diameter of 15 to 300 mm, a thickness of 1 to 5 mm, and is coaxially placed with the heat pipe (1).

7. A heat pipe baking reactor according to claim 6, characterized in that: The jacket (7) is arranged on the periphery of the mesh sleeve (11), leaving an annular gap of 5 to 10 mm.

8. The heat pipe baking reactor according to claim 1, characterized in that: The gas distribution plate (13) is made of stainless steel or carbon steel, with a diameter of 15 to 300 mm and a thickness of 1 to 5 mm.

9. The heat pipe baking reactor according to claim 1, characterized in that: The sealing head (8) is in the shape of a sphere, a cone, an ellipse or a flat cover, and is made of stainless steel or carbon steel, with a diameter of 15 to 300 mm and a thickness of 1 to 5 mm.

10. The heat pipe baking reactor according to claim 1, characterized in that: The material chamber (12) is a space composed of the fins (5), the outer wall surface of the condensation section (4), the mesh sleeve (11) and the gas distribution plate (13), and the material filling height is 0.1 to 9 m.

11. The heat pipe baking reactor according to claim 1, characterized in that: The preheating chamber (14) is a space formed by the gas distribution plate (13), the outer wall surface of the condensation section (4), the jacket (7) and the flange end cover (15), and has a height of 50 to 200 mm.

12. The heat pipe baking reactor according to claim 1, characterized in that: The gas channel (10) is an annular space formed by the fins (5) and the jacket (7), and the annular gap spacing is 2 to 20 mm.

13. A solid waste roasting pretreatment method using a heat pipe roasting reactor as claimed in any one of claims 1 to 12, characterized in that: When the baking reactor performs baking pretreatment on solid waste materials, the materials are loaded into the material chamber (12) from the upper end of the jacket (7), the jacket (7) and the head (8) are sealed and connected via flanges, the heat pipe insulation section (3) and the jacket (7) are both insulated, and a purge gas is introduced into the gas inlet (16) at the lower end of the flange end cover (15) to create a baking atmosphere, and a heat source is applied to the evaporation section (2) of the heat pipe. After the heat pipe is started, the working fluid inside the heat pipe flows in a vaporization / condensation phase change cycle, so that the entire condensation section (4) is heated. The material is in an axially uniform temperature state. After the purge gas reaches the baking temperature in the preheating chamber (14), it enters the gas channel (10) through the gas distribution plate (13). The material is baked under the conditions of indirect heat conduction of the fins (5) and convective heat transfer of the purge gas. At the same time, the baking gas is carried away by the purge gas through the exhaust holes (6) on the fins (5) and the gas channel (10). The material is baked quickly and evenly, avoiding uneven temperature distribution caused by material accumulation during the baking process, resulting in uneven baking products, and low energy utilization efficiency.

14. A method for pretreatment of solid waste by using a heat pipe type roasting reactor according to claim 12, characterized in that: The solid waste material can be a mixture of one or more solid wastes such as sludge, garbage, plastic and biomass.

15. The method for solid waste roasting pretreatment using a heat pipe roasting reactor according to claim 13, characterized in that: The heat source can be any one of solar energy, waste heat flue gas and a tubular furnace.

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