Regenerative condensation-proof flue gas conveying composite pipeline

Abstract

This utility model discloses a heat storage anti-condensation flue gas conveying composite pipeline, relating to the field of industrial gas conveying pipeline technology. The composite pipeline comprises, from the inside out, an inner lining layer, an insulation layer, a heat storage layer, a heat insulation layer, and a protective layer. The inner lining layer is made of corrosion-resistant material, the insulation and heat insulation layers are made of high-efficiency insulation materials, the heat storage layer is filled with a composite system of phase change fiber-doped aerogel and paraffin / epoxy resin phase change microcapsules, and the protective layer is made of high-strength material. When the inner diameter of the pipeline is less than 800mm, the thickness ratio of each layer is (1~3):(20~40):(15~25):(10~15):(1~3); when it is greater than 800mm, the ratio is (3~5):(30~50):(20~30):(15~20):(2~4). This composite pipeline is suitable for transporting a mixture of zinc vapor and carbon monoxide in the high-temperature carbothermal reduction zinc process. Through the synergistic effect of its multi-layer structure, it reduces heat loss, utilizes residual heat to maintain temperature stability, effectively prevents zinc vapor from condensing and agglomerating, and extends the service life of the pipeline.

Description

Technical Field

[0001] This utility model relates to the field of industrial gas transmission pipeline technology, specifically to a heat storage anti-condensation flue gas transmission composite pipeline. Background Technology

[0002] In the industrial production of high-temperature carbothermic zinc reduction, the zinc vapor and carbon monoxide mixed flue gas discharged from the reduction furnace not only reaches temperatures as high as 850℃ to 1000℃, but also contains zinc vapor with easy condensation characteristics, placing stringent requirements on the comprehensive performance of the conveying pipelines. The pipelines must simultaneously meet the requirements of high temperature resistance, wear resistance, and efficient heat insulation, with the external surface temperature of the pipeline controlled below 50℃ to avoid heat loss and premature condensation of zinc vapor.

[0003] Currently, the industry commonly uses internally insulated pipes, whose structure consists of an inner lining, an insulation layer, and an outer shell, with the layers connected and fixed by metal components. However, metal components have an inherent defect of high thermal conductivity, causing the high temperature inside the pipe to be rapidly conducted outward through the metal components. This results in an excessively rapid temperature drop inside the pipe, causing zinc to condense and adhere prematurely inside the pipe, gradually forming blockages. This not only fails to meet the insulation requirements but also poses safety hazards and affects the continuity of production. Utility Model Content

[0004] This utility model provides a heat storage anti-condensation flue gas conveying composite pipeline. By introducing phase change microcapsules into the heat storage layer to optimize the performance of the heat storage layer, the problem of zinc vapor condensation is solved. Through reasonable structural design and material selection, the condensation of zinc vapor in the pipeline during the high-temperature carbothermic reduction of zinc is effectively prevented, while enhancing the corrosion resistance of the pipeline and extending its service life.

[0005] This utility model provides a heat storage anti-condensation flue gas conveying composite pipe, including an inner lining layer. A heat insulation layer, a heat storage layer, a heat insulation layer, and a protective layer are coaxially laid on the outer wall of the inner lining layer from the inside to the outside. The heat storage layer is a heat storage layer made of phase change fiber doped with aerogel and paraffin / epoxy resin phase change microcapsules.

[0006] The inner lining is made of any one of SiC coating, high chromium alloy or silicon nitride ceramic material.

[0007] The insulation layer is made of any one of the following: nano-SiO2 aerogel composite material, double-network MK / SiO2 aerogel, or mullite nanofiber aerogel.

[0008] The paraffin / epoxy resin phase change microcapsules have a core-shell structure. The core material in the core-shell structure is modified paraffin with a phase change temperature of 500~600℃, and the shell material is epoxy resin. The particle size of the paraffin / epoxy resin phase change microcapsules is 50~200μm.

[0009] The paraffin / epoxy resin phase change microcapsules account for 30% to 50% of the total mass of the heat storage layer.

[0010] The aerogel in the phase change fiber doped aerogel is a nano-SiO2 aerogel.

[0011] The heat insulation layer is made of either nano-SiO2 aerogel composite material or ceramic fiber.

[0012] The protective layer is made of any one of stainless steel, aluminum alloy or reinforced plastic.

[0013] When the inner diameter of the pipe is less than 800mm, the thickness ratio of the inner lining, insulation layer, heat storage layer, heat insulation layer and protective layer is (1 ~ 3):(20 ~ 40):(15 ~ 25):(10 ~ 15):(1 ~ 3).

[0014] When the inner diameter of the pipe is greater than 800mm, the thickness ratio of the inner lining, insulation layer, heat storage layer, heat insulation layer and protective layer is (3 ~ 5):(30 ~ 50):(20 ~ 30):(15 ~ 20):(2 ~ 4).

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This novel composite pipeline achieves functional complementarity and synergistic efficiency through a multi-layered structural design. The inner lining layer, in direct contact with high-temperature flue gas, effectively resists the corrosive effects of the zinc vapor and carbon monoxide mixture, preventing leaks caused by corrosion damage to the pipeline's inner wall and extending its service life. The insulation and heat-resistant layers form a double thermal barrier, reducing heat loss. The heat storage layer employs a synergistic system of phase change fiber-doped phase change microcapsules and aerogel. This system absorbs or releases heat during temperature fluctuations through the phase change material and enhances insulation through the ultra-low thermal conductivity of the aerogel, improving the pipeline outlet temperature stability by over 20% and ensuring the flue gas remains above the critical condensation temperature of zinc vapor throughout the transport process. The protective layer provides mechanical protection for the overall structure, resisting external impacts and environmental erosion, and ensuring the structural integrity of each functional layer. The synergistic effect of this multi-layered composite pipeline solves the problem of premature condensation and agglomeration of zinc vapor within the pipeline, avoiding downtime for cleaning and waste of zinc resources due to blockages. This ensures the continuity and efficiency of gas transport in the high-temperature carbothermic reduction zinc process, improving process stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the cross-section of the composite pipe of this utility model.

[0019] Figure 2 This is a schematic diagram of the longitudinal section of the composite pipe of this utility model.

[0020] The components are: 1. Inner lining layer; 2. Thermal insulation layer; 3. Heat storage layer; 4. Heat insulation layer; 5. Protective layer. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of the embodiments of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the utility model product is in use. These are merely for the convenience of describing the utility model 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 the utility model. Furthermore, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 or an electrical 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 utility model according to the specific circumstances.

[0027] The heat storage and anti-condensation flue gas conveying composite pipeline provided by this utility model includes an inner lining layer 1, and a heat insulation layer 2, a heat storage layer 3, a heat insulation layer 4 and a protective layer 5 are coaxially laid on the outer wall of the inner lining layer 1 from the inside to the outside.

[0028] In some embodiments, the heat storage layer 3 is a heat storage layer made of a composite system of phase change fiber-doped aerogel and paraffin / epoxy resin phase change microcapsules, with the paraffin / epoxy resin phase change microcapsules accounting for 30% to 50% of the total mass of the heat storage layer. The paraffin / epoxy resin phase change microcapsules have a core-shell structure, with the core material being modified paraffin with a phase change temperature of 500 to 600°C and the shell material being epoxy resin. The particle size of the paraffin / epoxy resin phase change microcapsules is 50 to 200 μm. The aerogel in the phase change fiber-doped aerogel is nano-SiO2 aerogel. When the phase change fiber-doped phase change microcapsules are used as a pipeline heat storage layer, the two work synergistically to improve the heat storage density and temperature control accuracy, stabilize the temperature of the medium inside the pipeline, reduce leakage of the phase change material, and enhance the flexibility and structural stability of the layer, adapting to the requirements of pipeline curved surface fitting, and also reducing heat loss, making it suitable for pipeline insulation and cold insulation scenarios in different environments.

[0029] In some embodiments, the inner liner 1 is made of any one of SiC coating, high-chromium alloy, or silicon nitride ceramic material. When the inner liner comes into contact with high-temperature gas, these materials can withstand the scouring of high-temperature gas due to their excellent high-temperature resistance, avoiding deformation and damage at high temperatures. They also have high hardness and strong wear resistance, which can resist the wear of impurity particles in the gas and extend the pipeline life. At the same time, they have good chemical stability and are not prone to reacting with high-temperature gas, which meets the requirements of the high-temperature carbothermic reduction zinc process.

[0030] In some embodiments, the insulation layer 2 is an insulation layer made of any one of nano-SiO2 aerogel composite material, double-network MK / SiO2 aerogel, or mullite nanofiber aerogel; the heat insulation layer 4 is a heat insulation layer made of any one of nano-SiO2 aerogel composite material or ceramic fiber. The insulation layer and the heat insulation layer are made of high-efficiency insulation materials, forming a double thermal barrier to reduce heat loss of flue gas during transmission.

[0031] In some embodiments, the protective layer 5 is made of stainless steel, aluminum alloy, or reinforced plastic. Using these materials as the protective layer for the pipeline can effectively isolate external moisture and corrosive substances, prevent the inner layer of the pipeline from being corroded, and extend the overall service life. At the same time, these materials have excellent mechanical properties, can withstand external impacts or compression, protect the integrity of the internal structure, and have good processability, making them easy to adapt to the curved surface of the pipeline. They balance protection and installation convenience, meeting the needs of pipeline use in various scenarios.

[0032] In some embodiments, when the inner diameter of the pipe is less than 800 mm, the thickness ratio of the inner lining layer 1, the insulation layer 2, the heat storage layer 3, the heat insulation layer 4, and the protective layer 5 is (1 ~ 3):(20 ~ 40):(15 ~ 25):(10 ~ 15):(1 ~ 3); when the inner diameter of the pipe is greater than 800 mm, the thickness ratio of the inner lining layer 1, the insulation layer 2, the heat storage layer 3, the heat insulation layer 4, and the protective layer 5 is (3 ~ 5):(30 ~ 50):(20 ~ 30):(15 ~ 20):(2 ~ 4). By clearly defining the thickness ratio of each layer of the composite pipe under different pipe diameters, and accurately designing the structure of each layer according to the actual usage requirements of the pipe, the overall performance of the pipe is effectively improved.

[0033] The present invention will be further described below with reference to the accompanying drawings:

[0034] Example 1

[0035] This utility model provides a heat storage anti-condensation flue gas conveying composite pipeline, the method mainly includes:

[0036] The pipe has an inner diameter of 300mm. The inner lining layer 1 is made of high-chromium alloy material and is formed into a 2mm thick inner lining layer by thermal spraying. The insulation layer 2 is made of nano-SiO2 aerogel composite material and is installed using a prefabricated block assembly method, resulting in a 30mm thick insulation layer. The heat storage layer 3 is made of phase change fiber doped aerogel and paraffin / epoxy resin phase change microcapsules (containing 40% paraffin / epoxy resin phase change microcapsules), with a filling thickness of 20mm. The heat insulation layer 4 is made of nano-SiO2 aerogel composite material and has a thickness of 12mm. The protective layer 5 is made of stainless steel and has a thickness of 2mm. The thickness ratio of each layer is 2:30:20:12:2, which meets the thickness ratio requirements when the inner diameter is less than 800mm.

[0037] When this composite pipe is used in the high-temperature carbothermic reduction zinc process, the gas inlet temperature is 780℃, and after being transported through the pipe, the outlet temperature is maintained at around 515℃. This effectively prevents zinc vapor from condensing and condensing inside the pipe, and the pipe operates stably without corrosion, thus significantly extending its service life.

[0038] Example 2

[0039] This utility model provides a heat storage anti-condensation flue gas conveying composite pipeline, the method mainly includes:

[0040] The pipe has an inner diameter of 1000mm. The inner lining layer 1 is made of silicon nitride ceramic material, and a 6mm thick ceramic lining is fixed by the lining method. The insulation layer 2 uses double-network MK / SiO2 aerogel, and a 50mm thick insulation layer is formed by on-site foaming. The heat storage layer 3 uses phase change fiber doped aerogel and paraffin / epoxy resin phase change microcapsules (containing 50% paraffin / epoxy resin phase change microcapsules), with a filling thickness of 30mm. The heat insulation layer 4 is made of ceramic fiber, with a winding thickness of 22mm. The protective layer 5 is made of reinforced plastic with a thickness of 4mm. The thickness ratio of each layer is 6:50:30:22:4, which meets the thickness ratio requirements when the inner diameter is greater than or equal to 800mm.

[0041] When this composite pipeline was applied to actual production, the outlet temperature remained stable at around 530℃ while ensuring a gas inlet temperature of 780℃. This effectively avoided the problem of zinc vapor condensation. At the same time, the pipeline's corrosion resistance and mechanical strength met production requirements, and it was easy to maintain, thus reducing production and operating costs.

[0042] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model are within the protection scope of the claims of this utility model pending approval.

Claims

1. A heat storage anti-condensation flue gas conveying composite pipeline, characterized in that, It includes an inner lining layer (1), and a heat insulation layer (2), a heat storage layer (3), a heat insulation layer (4) and a protective layer (5) are coaxially laid on the outer wall of the inner lining layer (1) from the inside to the outside; the heat storage layer (3) is a heat storage layer made of phase change fiber doped aerogel and paraffin / epoxy resin phase change microcapsules.

2. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The inner lining (1) is made of any one of SiC coating, high chromium alloy or silicon nitride ceramic material.

3. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The insulation layer (2) is made of any one of nano-SiO2 aerogel composite material, double network MK / SiO2 aerogel or mullite nanofiber aerogel.

4. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The paraffin / epoxy resin phase change microcapsules have a core-shell structure. The core material in the core-shell structure is modified paraffin with a phase change temperature of 500~600℃, and the shell material is epoxy resin. The particle size of the paraffin / epoxy resin phase change microcapsules is 50~200μm.

5. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The paraffin / epoxy resin phase change microcapsules account for 30% to 50% of the total mass of the heat storage layer.

6. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The aerogel in the phase change fiber doped aerogel is a nano-SiO2 aerogel.

7. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The heat insulation layer (4) is a heat insulation layer made of either nano-SiO2 aerogel composite material or ceramic fiber.

8. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, The protective layer (5) is made of any one of stainless steel, aluminum alloy or reinforced plastic.

9. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, When the inner diameter of the pipe is less than 800mm, the thickness ratio of the inner lining (1), insulation layer (2), heat storage layer (3), heat insulation layer (4) and protective layer (5) is (1 ~ 3):(20 ~ 40):(15 ~ 25):(10 ~ 15):(1 ~ 3).

10. The heat storage anti-condensation flue gas conveying composite pipeline according to claim 1, characterized in that, When the inner diameter of the pipe is greater than 800mm, the thickness ratio of the inner lining (1), insulation layer (2), heat storage layer (3), heat insulation layer (4) and protective layer (5) is (3 ~ 5):(30 ~ 50):(20 ~ 30):(15 ~ 20):(2 ~ 4).

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