A device for preparing coal quality modified pitch at low temperature
Patent Information
- Application Number
- CN202521863334.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-31
- Publication Date
- 2026-09-04
- Estimated Expiration
- 2035-08-31
AI Technical Summary
传统高温热聚合法（400~450℃）制备煤质改质沥青存在以下缺陷：高温导致能源浪费及设备腐蚀；高温引发裂解、缩合等副反应，产物分子量分布宽，软化点波动大（±10℃）；高温下多环芳烃（PAHs）挥发，增加环保处理成本
[0012]The difference between this application and existing technologies lies in the use of three reactors: a prepolymerization stirring reactor, a polymerization reactor, and a final-state conditioning reactor, for gradient heating. Compared to heating coal tar pitch in a single reactor, this significantly reduces the residence time of the coal tar pitch within the same reactor. Simultaneously, the temperature change within each reactor is very small, significantly improving the problem of uneven heating of the coal tar pitch caused by large temperature variations, which leads to localized overheating and thus reduces coking of the coal tar pitch. Furthermore, a single reactor typically takes more than 5 hours from the start to the end of polycondensation. In contrast, this application uses three reactors for dispersed heating, with each reactor requiring only 2-3 hours of heating.
Smart Images
Figure CN224716562U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of modified asphalt processing equipment, and more particularly to an apparatus for preparing coal-based modified asphalt at low temperatures. Background Technology
[0002] Coal-modified pitch is produced from medium-temperature pitch extracted from coal tar distillation. During the heating and modification of this medium-temperature pitch, aromatic molecules in the pitch undergo thermal polymerization and condensation, ultimately producing coal-modified pitch. Modified coal pitch is widely used as a binder in electrolytic aluminum anode paste and carbon products. Traditional high-temperature thermal polymerization (400~450℃) methods for preparing coal-modified pitch have the following drawbacks: high temperatures lead to energy waste and equipment corrosion; high temperatures trigger side reactions such as cracking and condensation, resulting in a wide molecular weight distribution and large fluctuations in softening point (±10℃); and the volatilization of polycyclic aromatic hydrocarbons (PAHs) at high temperatures increases environmental treatment costs.
[0003] Existing technologies use catalysts to lower the reaction temperature, enabling the preparation of modified asphalt at lower temperatures. While catalysts can reduce the reaction activation energy and temperature, the reduced molecular motion rate at low temperatures needs to be compensated for by extending the reaction time to ensure the complete polymerization of polycyclic aromatic hydrocarbons into polymer components. Theoretically, extending the reaction time can make the polymerization reaction more complete, increasing the carbon content of the asphalt and thus improving the coking value of the product. However, in actual production, when medium-temperature asphalt polymerizes in the reactor, the large temperature difference between the initial and final heating temperatures makes it difficult for the asphalt to heat up synchronously. Localized materials undergo excessive polymerization or even carbonization due to prolonged high-temperature residence time, leading to increased coking in the product. This coking adheres to the inner walls of the equipment, the stirring shaft, and other locations, resulting in a decrease in the equipment's heat transfer coefficient and an increased likelihood of pipe blockage. Utility Model Content
[0004] In view of this, this application proposes an apparatus for preparing coal-modified bitumen at low temperature, which can improve the problem of increased coking caused by excessive agglomeration of materials.
[0005] An apparatus for preparing coal-modified bitumen at low temperature includes: Raw material storage tanks used to hold medium-temperature asphalt; A heating furnace for preheating medium-temperature asphalt, wherein the inlet of the heating furnace is connected to the outlet of the raw material storage tank; A prepolymerization mixing tank for prepolymerizing medium-temperature asphalt, wherein the inlet of the prepolymerization mixing tank is connected to the outlet of the heating furnace via a pipeline; A polymerization reactor for medium-temperature asphalt polymerization, wherein the inlet of the polymerization reactor is connected to the outlet of the prepolymerization stirring tank via a pipeline; A final-state conditioning vessel for deep polymerization of medium-temperature asphalt, wherein the inlet of the final-state conditioning vessel is connected to the outlet of the polymerization reactor via a pipeline.
[0006] In order to ensure that the material can be heated evenly in the heating furnace, the heating furnace is preferably a rotary kiln.
[0007] The coal tar pitch of this application releases a large amount of high-temperature gas during prepolymerization and polymerization. This gas is typically directly fed into a waste heat boiler for combustion. However, the high temperature of these gases leads to heat waste when used directly for combustion, and the high fuel temperature also results in a higher amount of nitrogen oxides generated after combustion. Therefore, preferably, the apparatus for preparing modified coal tar pitch at low temperatures further includes a heat exchanger. The heat pipes of the heat exchanger are connected to the exhaust ports of the prepolymerization stirring vessel, polymerization reactor, and final-state conditioning vessel via pipelines. The cold pipes of the heat exchanger are connected to the jacket of the raw material storage tank via pipelines, so as to use the heat from the high-temperature gas for preheating the raw material.
[0008] Since the gas temperatures emitted from the prepolymerization stirred tank, polymerization reactor, and final state conditioning tank are not the same, in order to make full use of the heat in the emitted gas, preferably, the jacket of the raw material storage tank is divided into a low-temperature jacket, a medium-temperature jacket, and a high-temperature jacket from top to bottom. Correspondingly, the heat exchangers include a low-temperature heat exchanger connected to the low-temperature jacket and the prepolymerization stirred tank, a medium-temperature heat exchanger connected to the medium-temperature jacket and the polymerization reactor, and a high-temperature heat exchanger connected to the high-temperature jacket and the final state conditioning tank.
[0009] The apparatus for preparing coal-modified bitumen at low temperatures according to this application further includes a waste heat boiler, the heat from which is used to heat a prepolymerization stirred tank. The fuel inlet of the waste heat boiler is connected to the heat pipe outlet of a heat exchanger via a pipeline. The exhaust gas from the prepolymerization stirred tank, polymerization reactor, and final-state conditioning tank is used as fuel for the waste heat boiler. The steam drum of the waste heat boiler is connected to the jacket of the prepolymerization stirred tank via a pipeline to heat the medium in the jacket of the prepolymerization stirred tank, such as heating hot oil or hot steam. Depending on the heat generated by fuel combustion in the waste heat boiler, in a preferred embodiment, the steam drum of the waste heat boiler is also connected to the jacket of the polymerization reactor via a pipeline. Furthermore, the steam drum of the waste heat boiler is also connected to the jacket of the final-state conditioning tank via a pipeline.
[0010] Preferably, the prepolymerization stirring tank, polymerization reactor, and final state conditioning tank of this application have the same structure, the difference being the heating temperature.
[0011] Preferably, the side walls of the prepolymerization stirring tank, polymerization reactor, and final state conditioning tank are also equipped with electric heating coils, which heat the coal tar pitch through the combined action of the electric heating coils and hot oil / hot steam.
[0012] The difference between this application and existing technologies lies in the use of three reactors: a prepolymerization stirring reactor, a polymerization reactor, and a final-state conditioning reactor, for gradient heating. Compared to heating coal tar pitch in a single reactor, this significantly reduces the residence time of the coal tar pitch within the same reactor. Simultaneously, the temperature change within each reactor is very small, significantly improving the problem of uneven heating of the coal tar pitch caused by large temperature variations, which leads to localized overheating and thus reduces coking of the coal tar pitch. Furthermore, a single reactor typically takes more than 5 hours from the start to the end of polycondensation. In contrast, this application uses three reactors for dispersed heating, with each reactor requiring only 2-3 hours of heating.
[0013] Compared with existing technologies, this application can significantly improve the coking of coal tar pitch. Simultaneously, due to the small temperature difference in the reactor, the coal tar pitch can fully condense, thereby increasing the coking value of the modified pitch. Furthermore, using three reactors can reduce the preparation time of the modified pitch. Attached Figure Description
[0014] Figure 1 This is a process flow diagram of a preferred embodiment of the apparatus for preparing coal-modified bitumen at low temperature according to this application. Figure 2 This is a process flow diagram of another preferred embodiment of the apparatus for preparing coal-modified bitumen at low temperature according to this application; Explanation of reference numerals in the attached drawings: 1. Raw material storage tank; 11. Low temperature jacket; 12. Medium temperature jacket; 13. High temperature jacket; 2. Heating furnace; 21. Spiral stirring blade; 3. Prepolymerization stirring vessel; 4. Polymerization reactor; 5. Final state conditioning vessel; 61. Low temperature heat exchanger; 62. Medium temperature heat exchanger; 63. High temperature heat exchanger; 7. Waste heat boiler; 71. Steam drum. Detailed Implementation
[0015] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0016] Please refer to Figure 1 An apparatus for preparing coal-modified bitumen at low temperature includes: Raw material storage tank 1 for holding medium-temperature asphalt; A heating furnace 2 for preheating medium-temperature asphalt, wherein the inlet of the heating furnace 2 is connected to the outlet of the raw material storage tank 1; The prepolymerization mixing tank 3 is used for prepolymerizing medium-temperature asphalt, and the inlet of the prepolymerization mixing tank 3 is connected to the outlet of the heating furnace 2 through a pipeline. The polymerization reactor 4 is used for medium-temperature asphalt polymerization, and the inlet of the polymerization reactor 4 is connected to the outlet of the prepolymerization stirring tank 3 through a pipeline. The final state conditioning vessel 5 is used for deep polymerization of medium-temperature asphalt, and the inlet of the final state conditioning vessel 5 is connected to the outlet of the polymerization reactor 4 through a pipeline.
[0017] Raw material storage tank 1 is used to store coal tar pitch and keep it in a fluid state. Taking medium-temperature coal tar pitch as an example, the softening temperature of medium-temperature coal tar pitch is 75~90℃, so raw material storage tank 1 needs to keep the medium-temperature coal tar pitch above 80℃.
[0018] The raw material storage tank 1 and the heating furnace 2 can be connected by a pipeline, or the raw material storage tank 1 can be placed above the heating furnace 2, with the discharge port of the raw material storage tank 1 facing the heating furnace 2.
[0019] When the raw material storage tank 1 is connected to the heating furnace 2 through a pipeline, a pump body is installed on the pipeline to extract the coal tar pitch in the raw material storage tank 1 into the heating furnace 2.
[0020] When the raw material storage tank 1 is located above the heating furnace 2, a discharge valve is provided at the bottom of the raw material storage tank 1. The flow rate of coal tar pitch entering the heating furnace 2 is controlled by controlling the opening and closing of the discharge valve.
[0021] Heating furnace 2 is used to preheat coal tar pitch. The polymerization temperature of medium-temperature coal tar pitch depends on the specific catalyst, generally between 320 and 370°C. If the coal tar pitch in raw material storage tank 1 is directly poured into prepolymerization stirring tank 3, the temperature difference from 80°C to the prepolymerization temperature will be at least 200°C. This easily leads to uneven heating of the material, resulting in excessively high local material temperatures and prolonged residence time, leading to increased coking. To ensure uniform heating of the material in heating furnace 2, in a preferred embodiment, please refer to... Figure 1 The heating furnace 2 is a rotary kiln. This allows the coal tar pitch to be stirred and pushed forward simultaneously. The rotary kiln can have its diameter appropriately reduced and its axial distance increased, enabling the coal tar pitch to be heated quickly and uniformly.
[0022] The coal tar pitch is heated while being pushed into the prepolymerization mixing tank 3. Those skilled in the art should understand that the heating furnace 2 is generally horizontal, but it can also be inclined.
[0023] In another preferred embodiment, such as Figure 2 As shown, the heating furnace 2 is a tubular furnace.
[0024] The prepolymerization stirred tank 3 is used to uniformly heat coal tar pitch to a prepolymerization state and remove low-boiling-point components from the coal tar pitch, avoiding the loss of β-resin precursors during high-temperature polymerization. The prepolymerization temperature is generally 20-40 degrees Celsius lower than the polymerization temperature. Slow heating in the prepolymerization stirred tank 3 can fully release low-boiling-point components. In addition, a catalyst is added to the prepolymerization stirred tank 3 to lower the activation energy of medium-temperature pitch.
[0025] The polymerization reactor 4 is used to uniformly heat the coal tar pitch to the temperature at which the polymerization reaction occurs, and to allow the coal tar pitch to polymerize gently, avoiding coking of the coal tar pitch due to excessively high temperature or rapid temperature changes.
[0026] The final state conditioning kettle 5 is used for continuous heating of coal tar pitch to achieve deep polymerization of coal tar pitch and improve the coking value of modified pitch.
[0027] The coal tar pitch of this application releases a large amount of high-temperature gas during prepolymerization and polymerization. This gas is typically directly fed into the waste heat boiler 7 for combustion. Since these gases are at high temperatures, direct combustion would result in a waste of heat. Furthermore, high fuel temperatures lead to a greater generation of nitrogen oxides after combustion.
[0028] Therefore, in a preferred embodiment, the apparatus for preparing coal-modified bitumen at low temperature according to this application further includes a heat exchanger. The heat pipes of the heat exchanger are connected to the exhaust ports of the prepolymerization stirring vessel 3, the polymerization reactor 4, and the final state conditioning vessel 5 via pipelines. The cold pipes of the heat exchanger are connected to the jacket of the raw material storage tank 1 via pipelines, so as to use the heat in the high-temperature gas for preheating the raw material. The jacket of the raw material storage tank 1 is filled with hot oil or hot steam. The cold pipes of the heat exchanger are connected to the jacket of the raw material storage tank 1, thereby using the heated hot oil or hot steam for preheating the coal-modified bitumen and reducing the energy consumption of the heating furnace 2.
[0029] Since the gas temperatures emitted from the prepolymerization stirred tank 3, polymerization reactor 4, and final state conditioning tank 5 are not the same, in order to fully utilize the heat in the emitted gas, the jacket of the raw material storage tank 1 is further divided from top to bottom into a low-temperature jacket 11, a medium-temperature jacket 12, and a high-temperature jacket 13. Correspondingly, the heat exchangers include a low-temperature heat exchanger 61 connected to the low-temperature jacket 11 and the prepolymerization stirred tank 3, a medium-temperature heat exchanger 62 connected to the medium-temperature jacket 12 and the polymerization reactor 4, and a high-temperature heat exchanger 63 connected to the high-temperature jacket 13 and the final state conditioning tank 5. In this way, the coal tar pitch is preheated gradually from top to bottom.
[0030] The apparatus for preparing coal-modified bitumen at low temperatures according to this application further includes a waste heat boiler 7, the heat from which is used to heat the prepolymerization stirred tank 3. The fuel port of the waste heat boiler 7 is connected to the heat pipe outlet of the heat exchanger via a pipeline. The exhaust gas from the prepolymerization stirred tank 3, the polymerization reactor 4, and the final state conditioning tank 5 is used as fuel for the waste heat boiler 7. The steam drum 71 of the waste heat boiler 7 is connected to the jacket of the prepolymerization stirred tank 3 via a pipeline for heating the medium in the jacket of the prepolymerization stirred tank 3, such as heating hot oil or hot steam.
[0031] In a preferred embodiment, the prepolymerization stirring tank 3, polymerization reactor 4, and final state conditioning tank 5 of this application have the same structure, the difference being the heating temperature of the coal tar pitch.
[0032] In a preferred embodiment, the side walls of the prepolymerization stirring tank 3, polymerization reactor 4, and final state conditioning tank 5 are further equipped with electric heating coils, which, together with hot oil / steam, heat the coal tar pitch. Because the electric heating coils offer high temperature controllability and rapid heating, the jacket is primarily used for heat preservation of the coal tar pitch, while the electric heating coils are used for heating it.
[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. An apparatus for preparing coal-modified bitumen at low temperature, characterized in that... include: (1) Raw material storage tanks used to hold medium-temperature asphalt. A heating furnace (2) for preheating medium-temperature asphalt, wherein the inlet of the heating furnace (2) is connected to the outlet of the raw material storage tank (1); A prepolymerization mixing tank (3) for prepolymerizing medium-temperature asphalt, wherein the inlet of the prepolymerization mixing tank (3) is connected to the outlet of the heating furnace (2) via a pipe; A polymerization reactor (4) for medium-temperature asphalt polymerization, wherein the inlet of the polymerization reactor (4) is connected to the outlet of the prepolymerization stirring tank (3) by a pipeline; The final state conditioning vessel (5) is used for deep polymerization of medium-temperature asphalt. The inlet of the final state conditioning vessel (5) is connected to the outlet of the polymerization reactor (4) through a pipeline.
2. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: The heating furnace (2) is a rotary kiln.
3. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: It also includes a heat exchanger, the heat pipe of which is connected to the exhaust port of the prepolymerization stirring vessel (3), the polymerization reactor (4), and the final state adjustment vessel (5) through a pipeline, and the cold pipe of the heat exchanger is connected to the jacket of the raw material storage tank (1) through a pipeline.
4. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: The jacket of the raw material storage tank is divided into a low temperature jacket (11), a medium temperature jacket (12), and a high temperature jacket (13) from top to bottom. Correspondingly, the heat exchangers include a low temperature heat exchanger (61) connected to the low temperature jacket (11) and the prepolymerization stirring vessel (3), a medium temperature heat exchanger (62) connected to the medium temperature jacket (12) and the polymerization reactor (4), and a high temperature heat exchanger (63) connected to the high temperature jacket (13) and the final state adjustment vessel (5).
5. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: It also includes a waste heat boiler (7), the fuel port of which is connected to the heat pipe outlet of the heat exchanger via a pipe, and the steam drum (71) of the waste heat boiler (7) is connected to the jacket of the prepolymerization stirring vessel (3) via a pipe.
6. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: The prepolymerization stirred tank (3), polymerization reactor (4), and final state conditioning tank (5) have the same structure.
7. The apparatus for preparing coal-modified bitumen at low temperature as described in claim 1, characterized in that: The side walls of the prepolymerization stirring tank (3), polymerization reactor (4), and final state conditioning tank (5) are also equipped with electric heating coils.