Application of Scraped Surface Evaporation for Concentration of Lithium-ion Battery Electrolyte Solvents

Process Description:
First, the raw material solution is transported to the feed tank. The raw liquid stored in the raw material tank is then transported to the raw material preheater via vacuum differential pressure or feed pump, and after preheating, it enters the thin film evaporator. Inside the evaporator, the raw liquid is heated and evaporated under vacuum conditions. The vapor phase is discharged from the light phase outlet, condensed through two condensers, and then enters the light phase tank. Once a certain liquid level is reached, it is continuously discharged through the light phase pump. The unevaporated heavy phase flows along the inner wall of the evaporator to the bottom and enters the heavy phase receiving tank. When a certain liquid level is reached, it is continuously discharged through the heavy phase discharge pump. This process achieves vacuum thin film evaporation separation of the material.

The feed section can achieve precise control of the feed volume through flow meters, control valves, and variable frequency feed pumps, with an error range of ≤1%. The evaporation section is controlled by variable frequency rotation of the scraper to ensure uniform film distribution and stable evaporation. The vapor phase is condensed through two stages of condensers to ensure complete condensation and minimize material loss. The liquid levels in the light phase and heavy phase tanks are interconnected with the discharge pumps to ensure continuous and stable discharge. High-vacuum discharge pumps are used to ensure smooth discharge under vacuum conditions. The vacuum system can be adjusted to the desired vacuum level, ranging from 15KPa to 1KPa. The feed volume, vacuum level, and temperature are interconnected to ensure the quality of the heavy phase components. Multiple temperature sensors, pressure sensors, flow sensors, and level sensors are installed at various locations in the system to accurately monitor the operating temperature, pressure, level, and feed volume. The entire system can operate fully automatically without human intervention.

System Installation and Commissioning:
The equipment is large in size, and the customer requires on-site installation and commissioning. During the commissioning phase, the vacuum level is set to -0.095MPa based on the evaporation temperature conditions. During the feeding process, we gradually increased the feed volume and heating temperature. When the feed volume reached 4200kg/h, the evaporation capacity reached a maximum of 3500kg/h, exceeding customer expectations. Due to the short heating time, the product quality has significantly improved compared to the original process.

Application Scenarios:
Scraped surface evaporators are widely used in industries such as petroleum, chemical, and pharmaceuticals, particularly for high-viscosity materials (such as tannin, honey, etc.) and materials prone to crystallization, scaling, and heat sensitivity.

Ekaislot Advantages:
The project involves the design, manufacturing, and installation of process, equipment, and control systems, covering fields such as structure, equipment, instrumentation, electrical, safety, and environmental protection. Although the scale is not large, the breadth of involvement poses certain difficulties and complexities. Shanghai Ekaislot possesses the qualifications for pressure vessel manufacturing, has 14 years of experience in equipment design and manufacturing, and has a team of experienced process technicians. The company has a track record in the design and manufacturing of scraped surface evaporator test units, three-in-one test units, silicon carbide membrane test units, candle filter test units, vacuum test units, and microchannel reactor test units. Currently, the company’s scraped surface evaporators have been systematized and standardized, with standard equipment evaporation areas ranging from 0.1 to 1㎡ for small and medium-sized pilot projects and 1 to 90㎡ for large-scale production projects. Non-standard equipment can be customized according to customer site conditions. To date, the company has completed more than a hundred scraped surface evaporator projects.