Process optimization method combining wet mixing and rotary drum devolatilization

Abstract

The invention relates to a process optimization method combining wet mixing and rotary drum devolatilization, and aims to improve the production efficiency, the energy-saving effect and the solvent recovery rate. According to the method, by introducing an intelligent control system and a self-adaptive PID control algorithm, parameters such as the temperature, the humidity and the airflow rate in the wet mixing and rotary roller devolatilization process are adjusted in real time, and optimal control over the process is achieved. A plurality of independent temperature control sections are arranged in the rotary drum, materials are heated step by step to optimize the volatilization efficiency of the solvent, meanwhile, a rotary booster and an airflow enhancing device are arranged, the fluidity of the materials and airflow distribution are improved, and solvent volatilization is further accelerated. And the solvent recovery system recovers the solvent in the waste gas through a condensing device, and the solvent is filtered and then put into the wet mixing process again. In addition, the waste heat recovery system recovers waste heat in waste gas through the heat exchanger, and consumption of external energy is reduced. The solvent evaporation efficiency can be remarkably improved, the energy consumption is reduced, the solvent is effectively recovered, and the environmental pollution is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of material processing and heat treatment, and in particular to a process optimization method combining wet mixing and rotary drum devolatilization. Background Art

[0002] Wet mixing and rotary drum devolatilization are common processing technologies in many industrial production processes. Wet mixing is a process that mixes solvents or water with materials to make them evenly dispersed in a wet state, and is suitable for the production of polymer materials and synthetic chemicals. However, there are usually problems with the volatilization rate and humidity control of the solvent during wet mixing, resulting in low efficiency, high energy consumption, and large material losses in the devolatilization process. As a common dehydration and devolatilization equipment, rotary drum devolatilization can improve the volatilization efficiency to a certain extent, but the optimization of the process is still plagued by problems such as uneven temperature control, unreasonable airflow distribution, and poor material fluidity of traditional rotary drums.

[0003] In the prior art, the solvent volatilization efficiency after wet mixing is low, and the heating and airflow control of the rotary drum often lead to energy waste and process instability. Therefore, how to improve the overall efficiency of wet mixing and rotary drum devolatilization has become a technical problem to be solved urgently. Summary of the invention

[0004] The present invention relates to a process optimization method combining wet mixing and rotary drum devolatilization, aiming to improve the production efficiency, energy saving effect and solvent recovery rate in the process of wet mixing and rotary drum devolatilization. By combining an intelligent control system, precise temperature control, a rotary booster, an airflow enhancement device and solvent recovery technology, the present invention provides an optimization process, which solves the problems of uneven temperature distribution, low solvent volatilization efficiency, energy waste and environmental pollution in the prior art, thereby significantly improving the process efficiency, reducing energy consumption and improving the solvent recovery rate.

[0005] To achieve the above objectives, the technical solution of the present invention optimizes the existing process by the following key technical means:

[0006] Introduction of intelligent control system: The present invention adopts adaptive PID control algorithm. The intelligent control system can automatically adjust the process parameters according to the real-time data (material humidity, temperature and air flow rate) during wet mixing and rotary drum devolatilization, ensuring the optimal working state of each process link, reducing manual intervention and improving the automation and stability of production.

[0007] Design of temperature control sections in the rotary drum: In order to optimize the solvent volatilization effect, the present invention sets multiple independent temperature control sections in the rotary drum. The temperature of each temperature control section is gradually adjusted according to the volatilization requirements of the material, ensuring that the material is evenly heated in the rotary drum, avoiding the energy waste and low solvent volatilization efficiency caused by uneven temperature.

[0008] Rotating booster and airflow enhancement device: The present invention installs a spiral rotating booster in the rotary drum to enhance the fluidity of the material and increase the contact area between the material and the heated air, effectively accelerating the volatilization rate of the solvent. In addition, the airflow distribution in the rotary drum is optimized by setting a pressurized fan and an air duct adjustment device to further improve the efficiency of solvent volatilization.

[0009] Solvent recovery system: The present invention is equipped with a solvent recovery system, which recovers solvent from exhaust gas through a condenser and removes impurities through a sophisticated filtration system to ensure that the recovered solvent can be efficiently and cleanly returned to the wet mixing process, thereby improving resource utilization and effectively reducing pollution to the environment.

[0010] Waste heat recovery system: The present invention also designs a waste heat recovery system, which recovers the waste heat in the exhaust gas in the rotary drum through a heat exchanger, and uses the recovered heat to preheat the material or solvent in the wet mixing process, thereby reducing the consumption of external energy and further improving the energy utilization efficiency.

[0011] Adjustment function based on material characteristics: The intelligent control system of the present invention also has an adjustment function based on material characteristics, which can automatically adjust the heating power, air flow rate and material fluidity of the rotary drum according to the humidity, temperature and volatility parameters of the material in real time to ensure the optimal effect of the devolatilization process.

[0012] Through the application of the above technical means, the present invention effectively solves the problems of uneven temperature distribution, incomplete solvent volatilization, and serious energy waste in the prior art, greatly improves the efficiency of wet mixing and rotary drum devolatilization process, reduces the energy consumption of solvent volatilization, and improves the solvent recovery rate. At the same time, environmental pollution in the process is effectively controlled, which meets the current technical requirements of energy conservation and environmental protection.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] Improve solvent evaporation efficiency: Precise temperature control design and airflow optimization significantly increase the solvent evaporation rate and greatly improve production efficiency.

[0015] Energy saving and environmental protection: The application of waste heat recovery and solvent recovery systems effectively reduces energy consumption, improves solvent recovery rate, and reduces waste gas emissions.

[0016] Intelligent control system: Automated control can optimize process parameters in real time, improve the stability and flexibility of the production process, and reduce human intervention.

[0017] Improve resource utilization: The design of solvent recovery and waste heat recovery systems enables more efficient use of resources and reduces production costs.

[0018] In summary, the present invention provides a new wet mixing and rotary drum devolatilization process optimization method, which has strong innovation and practicality and is suitable for various industrial production processes requiring wet mixing and solvent volatilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the optimization process of the wet mixing and rotary drum devolatilization process according to an embodiment of the present invention;

[0021] Figure 2 It is a schematic diagram of the layout of the temperature control section and the rotary booster of the rotary drum according to an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of a flow enhancement device and a solvent recovery system according to an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of a waste heat recovery system and an intelligent control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0025] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0026] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0027] See also Figures 1 to 4

[0028] 1. Linkage control system of wet mixing and rotary drum

[0029] Real-time monitoring and feedback control of temperature and humidity

[0030] During the wet mixing process, humidity sensors and temperature sensors are installed to monitor the humidity and temperature of the materials in real time. The sensors input the collected data into the intelligent control system through the data acquisition system. The system automatically adjusts the heating power and wind speed of the rotary drum according to the humidity and temperature data fed back by the sensors. Before the wet mixed materials enter the rotary drum, the intelligent control system adjusts the working conditions of the rotary drum according to the real-time data to ensure the efficient and uniform devolatilization process.

[0031] Adaptive control algorithm

[0032] Adaptive PID control algorithm is used to automatically adjust the temperature, humidity and airflow rate during wet mixing and rotary drum devolatilization. The solvent volatilization rate during wet mixing is closely related to the humidity and temperature of the material. The intelligent control system optimizes the devolatilization parameters based on real-time feedback of humidity and temperature data to ensure that each process stage is in the best state, thereby improving production efficiency and avoiding energy waste.

[0033] 2. Multi-stage temperature control design of rotary drum

[0034] Multi-zone temperature control design

[0035] There are multiple independent temperature control sections inside the rotary drum, and each section independently adjusts the temperature according to the different volatilization requirements of the material. A lower temperature section is set at the feeding end of the rotary drum to preliminarily heat the material and start the volatilization of the solvent; a medium temperature section is set in the middle to continue heating and accelerate the volatilization of the solvent; a higher temperature section is set at the discharge end to ensure that the solvent in the material is completely volatilized. Each temperature control section is controlled by an independent temperature control system to ensure uniform temperature distribution and avoid local overheating or incomplete solvent volatilization.

[0036] Temperature control device

[0037] Each temperature control section uses high-precision temperature sensors and heating elements (such as electric heating tubes, steam heating tubes), and the intelligent control system adjusts the heating power and temperature of each section in real time to ensure the uniformity and stability of the temperature inside the rotary drum. The temperature control system automatically adjusts the heating power based on the preset temperature gradient and real-time feedback data to prevent local overheating or low temperature from causing material damage or energy waste.

[0038] 3. Optimization of material flow mechanism

[0039] Rotation booster design

[0040] A spiral rotary booster is installed inside the rotary drum. The rotary booster drives the material to flow along the axial direction of the drum through mechanical rotation, ensuring full contact between the material and the air and promoting the volatilization of the solvent. The speed of the booster is adjusted according to the characteristics of the material (such as humidity and particle size) to maintain the best material fluidity and volatilization effect. The rotary booster can effectively increase the contact area between the material and the heated air, thereby accelerating the volatilization process of the solvent.

[0041] Airflow Enhancer

[0042] The rotary drum is equipped with an efficient airflow distribution system, which uses a pressurized fan and air duct adjustment device to ensure that the airflow is evenly distributed in the rotary drum. The wind speed and direction can be adjusted in real time through an intelligent control system to ensure the best coordination between the airflow and the material, avoiding material retention or incomplete solvent volatilization caused by uneven airflow. The airflow enhancement system greatly improves the volatilization efficiency of the solvent and reduces energy waste.

[0043] 4.Solvent recovery and reuse system

[0044] Solvent recovery unit

[0045] The exhaust gas after the rotary drum devolatilization is processed by the condensation device. The condenser adopts a double-layer pipeline design. The cooling medium flows through the outer pipeline, and the exhaust gas is cooled through the inner pipeline to separate the solvent from the exhaust gas. The condensed solvent is removed by precision filtration and separation devices to remove impurities, and then input into the wet mixing process for reuse. The solvent recovery device has a high solvent recovery rate, ensuring that the recovered solvent reaches the purity required for wet mixing.

[0046] Solvent recycling system

[0047] The treated recovered solvent is returned to the wet mixing process through the storage device to form a closed-loop reflux system. The system can adjust the reflux volume and reflux temperature of the solvent according to actual needs to ensure that the concentration and humidity of the solvent in the wet mixing process are in the optimal range. Through this solvent recycling system, not only the consumption of solvent is reduced, but also the procurement cost of solvent is reduced, and the environmental pollution caused by solvent emissions is reduced.

[0048] 5. Energy saving and waste heat recovery

[0049] Waste heat recovery system

[0050] The waste heat generated by the rotary drum during the devolatilization process is recovered through the heat exchanger, and the waste heat is used to preheat the materials or solvents in the wet mixing process. The heat exchanger uses high-efficiency heat exchange materials and designs to ensure that the waste heat recovery rate reaches more than 90%. The recovered heat is used to heat the feed materials or water, reducing the consumption of external energy and significantly reducing energy costs.

[0051] Solar Assist System

[0052] In a suitable production environment, a solar water heating system is installed to provide heat to the heating system of the rotary drum through solar energy. The solar energy system works together with the waste heat recovery system to reduce traditional energy consumption and meet the production requirements of energy conservation and environmental protection.

[0053] Example 1 (Wet mixing of polymer materials and rotary drum devolatilization process)

[0054] In this embodiment, the polymer material is processed by wet mixing and rotary drum devolatilization process. The polymer material is mixed with NMP (N-methylpyrrolidone) solvent, and then the solvent is devolatilized by a rotary drum. The inner diameter of the rotary drum is 1.5 meters, the length is 3 meters, and the operating temperature is set to three sections of 80°C, 100°C, and 130°C to ensure that the solvent is gradually volatilized and a suitable recovery rate is achieved.

[0055] Wet mixing process

[0056] During the mixing process, polymer materials are wet mixed with NMP solvent to ensure that the solvent is evenly distributed in the material. The wet mixing equipment is equipped with an agitator to promote the mixing of the solvent and the material by providing sufficient shear force.

[0057] Rotary drum devolatilization process

[0058] In the rotary drum, the material contacts the hot air by rotating, and the solvent is volatilized and carried away by the airflow. The airflow rate in the rotary drum is set to 4m / s, and the volatilization rate is calculated by the following formula:

[0059]

[0060] is the volatilization rate (g / s);

[0061] k evap is the volatility coefficient (m / s), which is selected according to the characteristics of different materials and solvents;

[0062] A is the contact area inside the rotary drum (m 2 ), assuming the contact area is 4.5m 2 ;

[0063] P vapor is the vapor pressure of NMP (Pa), which is approximately 40.5 kPa at 80 °C;

[0064] P ambient is the ambient air pressure (Pa), usually 101.3 kPa;

[0065] When the air flow rate is 4m / s, the volatilization rate is 500g per hour.

[0066] Solvent Recovery System

[0067] The solvent recovery system uses a condensing device to condense and recover the NMP solvent that evaporates into the air flow. The recovery rate is calculated using the following formula:

[0068]

[0069] R recovery is the solvent recovery rate (%);

[0070] m recovered is the mass of solvent recovered (g);

[0071] m total is the total mass of the original solvent (g);

[0072] Through this process, the recovery rate of NMP solvent can reach 98%.

[0073] Rotary drum temperature control

[0074] The heating system of the rotary drum adopts a three-stage temperature control section setting, and the temperatures are set at 80℃, 100℃ and 130℃ respectively. The heating power of each section can be calculated by the following formula:

[0075] Q=m·C·ΔT

[0076] Q is the required heating power (J);

[0077] m is the mass of the material (kg), assuming the mass of the material is 200kg;

[0078] C is the specific heat capacity of the material (J / kg·℃), assuming the specific heat capacity is 1.5J / kg·℃;

[0079] ΔT is the temperature change (°C). Assume that the temperature is heated from 80°C to 130°C, that is, ΔT = 50°C.

[0080] Calculate the heating power required for each temperature control zone as:

[0081] Q == 200 · 1.5 · 50 = 15,000 J

[0082] The heating power requirement for each temperature control section is 15 kW to ensure the best solvent volatilization effect.

[0083] Airflow enhancement and material flow mechanism

[0084] To enhance the contact effect between the airflow and the material, a spiral rotating booster is installed inside the rotary drum, and the wind speed is set at 4 m / s to ensure the uniform flow of the material and the efficient volatilization of the solvent. The airflow enhancement device cooperates with the temperature control system to improve the solvent volatilization efficiency by optimizing the airflow distribution.

[0085] Waste heat recovery

[0086] A waste heat recovery device is installed at the exhaust end of the rotary drum to recover the waste heat in the airflow through a heat exchanger, improving the energy utilization efficiency of the process. The waste heat recovery efficiency is calculated by the following formula:

[0087]

[0088] η heat is the waste heat recovery efficiency (%);

[0089] Q recovered is the recovered heat (J);

[0090] Q total is the original heat (J).

[0091] By optimizing the waste heat recovery system, energy consumption can be effectively reduced and the overall system efficiency can be improved.

[0092] Example 2 (Wet mixing and devolatilization process of lithium battery slurry)

[0093] This example is used for the wet mixing of lithium battery cathode material slurry and the devolatilization process of solvents (such as NMP). A rotary drum devolatilization process similar to that of Example 1 is adopted, but a higher solvent recovery efficiency is required. The airflow rate inside the rotary drum is set at 6 m / s to increase the volatilization rate, and a more efficient condensation device is used in the recovery system, with a recovery rate reaching 99%. The volatilization rate is calculated using the same formula as above:

[0094]

[0095] By optimizing the airflow and temperature control system, the solvent volatilization efficiency is improved, and the solvent recovery rate is ensured to reach 99%, providing an efficient process guarantee for the production of lithium battery slurry.

[0096] Example 3 (Wet mixing of chemical powder and rotary drum devolatilization process)

[0097] This embodiment is aimed at the wet mixing of chemical powders (pigments, coatings) and the devolatilization process of aqueous solvents (such as water), and adopts a rotary drum temperature control and airflow enhancement system. The calculation of the volatilization rate and solvent recovery rate is similar to that of Example 1, but because aqueous solvents are processed, the recovery device is relatively simple. The calculation formula used by the temperature control system is:

[0098] Q=m·C·ΔT

[0099] The temperature of the material is heated from 70℃ to 90℃, and the heating power is calculated as follows:

[0100] Q=200·4.2·20=16,800J

[0101] Example 4 (Wet Mixing and Devolatilization Process of Ceramic Raw Materials)

[0102] This embodiment is used for wet mixing and water devolatilization of ceramic raw materials. The temperature control section is 70℃ and 90℃, and the moisture content of the material is relatively high, so the temperature control system is relatively simple, and the focus is on the uniform volatilization of water. The solvent recovery system mainly processes water vapor and optimizes energy consumption through the rate of water evaporation and waste heat recovery.

[0103] The above calculation formula is also used to optimize the heating power and air flow rate of the rotary drum to ensure that the moisture in the ceramic raw materials can be fully evaporated.

[0104] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process optimization method combining wet mixing and rotary drum devolatilization, characterized in that: An intelligent control system is used to control the wet mixing and rotary drum devolatilization processes in a linked manner. The specific steps include: During the wet mixing process, the humidity and temperature of the material are monitored in real time, and the working conditions of the rotary drum are adjusted according to the data fed back by the sensor; In the rotary drum, multiple independent temperature control sections are set, and each temperature control section independently adjusts the temperature according to the volatilization requirements of the material; Install a rotary booster inside the rotary drum to enhance the fluidity of the material and increase the contact area between the material and the heated air; An airflow enhancement device is installed in the rotary drum to optimize airflow distribution and improve solvent volatilization efficiency; A solvent recovery system is configured to recover the solvent from the exhaust gas and return the solvent to the wet mixing process after fine filtration; The volatility rate is calculated by the following formula: is the volatilization rate, k evap is the volatility coefficient, A is the contact area in the rotary drum (m 2 ), P vapor is the vapor pressure of NMP (Pa), P ambient is the ambient air pressure (Pa).

2. The process optimization method according to claim 1, characterized in that: The intelligent control system adopts an adaptive PID control algorithm to automatically adjust the temperature, humidity and air flow rate during wet mixing and rotary drum devolatilization to optimize the working state of each process link.

3. The process optimization method according to claim 1, characterized in that: The temperature control system of the rotary drum includes multiple independent temperature control sections. Each section adjusts the temperature through a temperature control device, and the temperature value of each section gradually increases according to the volatilization requirements of the material. The temperature adjustment power is calculated by the following formula: Q=m·C·ΔT Q is the required heating power, m is the mass of the material, C is the specific heat capacity of the material, and ΔT is the temperature change.

4. The process optimization method according to claim 1, characterized in that: The rotary booster in the rotary drum is spiral-shaped, which drives the material to flow along the axial direction of the drum and enhances the contact between the material and the air, thereby improving the volatilization efficiency of the solvent.

5. The process optimization method according to claim 1, characterized in that: The airflow enhancement device in the rotary drum includes a pressurized fan and an air duct adjustment device, which are used to ensure uniform distribution of the airflow in the rotary drum, thereby promoting the volatilization of the solvent.

6. The process optimization method according to claim 1, characterized in that: The solvent recovery system condenses and separates the solvent in the waste gas through a condenser, and the condensed solvent is filtered to remove impurities and then re-entered into the wet mixing process for reuse.

7. The process optimization method according to claim 1, characterized in that: The process also includes a waste heat recovery system, which recovers waste heat in the rotary drum through a heat exchanger and uses the recovered heat to preheat the materials and solvents in the wet mixing process. The waste heat recovery rate is calculated by the following formula: η heat is the waste heat recovery efficiency, Q recovered is the recovered heat, Q total The original heat.

8. The process optimization method according to claim 7, characterized in that: The waste heat recovery system recovers waste heat from the exhaust gas in the rotary drum through a heat exchanger, and the waste heat is used to heat feed materials and solvents to reduce the consumption of external energy.

9. The process optimization method according to claim 1, characterized in that: The intelligent control system also includes an adjustment function based on material characteristics, which can adjust the heating power, air flow rate and material fluidity of the rotary drum in real time according to the humidity, temperature and volatility parameters of the material.

10. The process optimization method according to claim 1, characterized in that: The solvent recovery system comprises a set of solvent separation device and filtering system, and the system recovers and processes the solvent in the waste gas through separation technology.

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