Application Case of High-Speed Disperser and High-Shear Emulsifier
In the production process of liquid and semi-solid products with multi-component and high-viscosity characteristics, the combination of high-speed dispersers and high-shear emulsifiers plays a crucial role in ensuring material uniformity, fineness and product stability. A production facility engaged in the processing of complex mixed materials once encountered persistent bottlenecks in material dispersion and emulsification, which led to unstable product quality and low production efficiency. After introducing a combined system of high-speed dispersers and high-shear emulsifiers, the facility successfully resolved these issues, achieving significant improvements in production performance and product consistency.
Background and Existing Challenges
The facility mainly processes mixed materials containing solid powders, oil phases and water phases, with a daily production capacity requirement of 180 to 250 tons. The production line operates in three shifts, with each shift running continuously for 8 hours. Prior to the equipment upgrade, the facility relied on a single traditional mixing device to complete both dispersion and emulsification processes, resulting in the following prominent problems:
- Inadequate solid-liquid dispersion effect: The traditional mixing equipment could not effectively break down agglomerated solid powder particles (initial particle size 50-100 μm) in the material system. After mixing, a large number of fine agglomerates remained, leading to uneven material composition. During the subsequent processing, these agglomerates would cause blockages in pipelines and nozzles, resulting in unplanned production shutdowns 2-3 times per week on average.
- Poor emulsification stability: The equipment lacked sufficient shear force to realize complete fusion between oil and water phases. The finished product often showed stratification or delamination phenomena after 15-20 days of storage, with the oil-water separation rate reaching 12-15%. This not only affected product usability but also increased the cost of rework and waste disposal, with the product qualification rate only maintained at 82-85%.
- Low production efficiency and high energy consumption: Due to the poor processing effect of the single equipment, each batch of materials required repeated mixing and emulsification for 40-50 minutes to barely meet the basic quality requirements. The equipment operated at a fixed high power for a long time, resulting in high unit energy consumption. The average daily electricity consumption reached 320 kWh, and the equipment maintenance frequency was high, with the average availability rate only 80%.
- Large batch-to-batch quality fluctuation: The traditional equipment lacked precise control over dispersion speed, emulsification time and shear force. The sensory quality (texture, uniformity) and physical and chemical indicators (viscosity, particle size distribution) of products from different batches showed obvious differences. This made it difficult for the facility to establish stable production processes and meet the consistent quality requirements of downstream applications.
Equipment Configuration and Process Optimization Plan
To address the above problems, the facility optimized the production process and introduced a combined processing system consisting of high-speed dispersers and high-shear emulsifiers, forming a "pre-dispersion - deep emulsification - stable mixing" integrated processing mode. The key configuration of the equipment and process optimization measures are as follows:
1. Key Configuration of High-Speed Disperser
The selected high-speed disperser is equipped with a turbine-type dispersing disc with a diameter of 200 mm, made of 316L stainless steel. The dispersing speed can be adjusted steplessly within the range of 800-3000 rpm through frequency conversion control, generating a maximum linear speed of 28 m/s. The equipment is equipped with a lifting mechanism that can adjust the height of the dispersing disc within 300-800 mm, adapting to different material levels in the mixing tank (volume 5000 L). In addition, the disperser is equipped with a torque monitoring device that can automatically adjust the operating speed according to the resistance change of materials during the dispersion process, avoiding overload and ensuring stable operation.
2. Key Configuration of High-Shear Emulsifier
The matched high-shear emulsifier adopts a four-stage stator-rotor structure with a shear gap of 0.08-0.2 mm. The rotor speed can be continuously adjusted between 3000-12000 rpm, generating a shear rate of up to 75000 s⁻¹. The equipment is installed at the bottom of the mixing tank, realizing inline continuous emulsification of materials. It is equipped with a jacketed temperature control device that can control the material temperature during emulsification within the range of 25-80℃, with a temperature fluctuation accuracy of ±1℃, avoiding the loss of active ingredients or material deterioration caused by excessive temperature rise during high-speed shearing.
3. Process Optimization Measures
The original single-step processing process was adjusted to a three-step combined process, realizing the rational division of labor between the two types of equipment:
- Pre-dispersion stage: First, add water-phase materials into the mixing tank, start the high-speed disperser, and adjust the speed to 2000-2500 rpm. Then, slowly add solid powder materials into the tank while stirring, and carry out pre-dispersion for 10-15 minutes. This process can quickly break down large agglomerates of solid particles and disperse them evenly in the water phase, reducing the load of subsequent emulsification processing.
- Deep emulsification stage: After completing the pre-dispersion, add oil-phase materials into the mixing tank, start the high-shear emulsifier while maintaining the operation of the high-speed disperser. Adjust the disperser speed to 1200-1500 rpm and the emulsifier speed to 8000-10000 rpm, and carry out combined processing for 15-20 minutes. The high-speed disperser ensures the overall uniformity of materials, while the high-shear emulsifier generates strong shear force to realize the complete fusion of oil and water phases and break down fine particles to the required size.
- Stable mixing stage: After emulsification, reduce the speed of the high-shear emulsifier to 3000-4000 rpm and the speed of the high-speed disperser to 800-1000 rpm, and carry out low-speed stable mixing for 5-8 minutes. This process eliminates the internal stress of the material system, stabilizes the emulsion structure, and ensures the long-term storage stability of the finished product.
Application Effect and Data Analysis
After 6 months of trial operation and parameter optimization, the combined system of high-speed disperser and high-shear emulsifier has achieved remarkable results in improving product quality, enhancing production efficiency and reducing operational costs. The specific data comparison before and after the equipment upgrade is as follows:
1. Significant Improvement in Product Quality
The particle size distribution of the finished product was significantly optimized. After pre-dispersion by the high-speed disperser, the average particle size of solid particles was reduced from 50-100 μm to 8-12 μm. After further emulsification by the high-shear emulsifier, the final average particle size of the product was controlled at 1-3 μm, and the polydispersity index (PDI) was maintained below 0.2. The oil-water separation rate of the product during storage was reduced from 12-15% to less than 2% after 60 days of storage, and the product stability was greatly improved. The product qualification rate increased from 82-85% to 99.2%, basically eliminating the cost of rework and waste disposal.
2. Remarkable Improvement in Production Efficiency
The combined processing mode shortened the single-batch processing time from 40-50 minutes to 30-35 minutes, and the processing efficiency was improved by about 25%. The number of unplanned shutdowns caused by pipeline blockages was reduced from 2-3 times per week to 0-1 times per month, and the equipment availability rate was increased from 80% to 95%. With the same daily production capacity (180-250 tons), the facility reduced the operating time of each shift by 1 hour, reducing labor costs while ensuring production tasks are completed on time.
3. Effective Reduction in Energy Consumption and Maintenance Costs
The frequency conversion control function of the two types of equipment realized adaptive adjustment of power according to the processing stage. The average daily electricity consumption of the production line was reduced from 320 kWh to 240 kWh, a decrease of 25%, saving 29,200 kWh of electricity annually. The high-speed disperser and high-shear emulsifier adopt wear-resistant materials and optimized structural design, reducing the frequency of vulnerable parts replacement. The monthly maintenance cost was reduced from 8,000 yuan to 3,500 yuan, and the annual maintenance cost was saved by about 54,000 yuan.
4. Stabilization of Batch-to-Batch Quality
The precise control system of the equipment realizes accurate control of dispersion speed, emulsification time, shear force and temperature. The coefficient of variation (CV) of key quality indicators (viscosity, particle size distribution) between different batches of products was reduced from 18-22% to 3-5%, achieving stable consistency of product quality. This not only meets the quality requirements of downstream applications but also provides a reliable basis for the facility to optimize production processes and improve product competitiveness.
Key Experience and Operation Notes
During the application process, the facility summarized the following key experiences and operation notes to ensure the stable operation of the combined equipment system and give full play to its performance:
- The sequence of material addition and the speed matching between high-speed disperser and high-shear emulsifier are crucial to the processing effect. It is necessary to avoid adding solid powder materials too quickly during pre-dispersion, and ensure that the disperser maintains sufficient speed to prevent secondary agglomeration of particles.
- Regularly check the wear condition of the dispersing disc of the high-speed disperser and the stator-rotor of the high-shear emulsifier. When the wear amount exceeds 0.5 mm, timely replacement is required to avoid reducing the dispersion and emulsification effect.
- During the emulsification process, strictly control the material temperature. For heat-sensitive materials, the emulsifier speed should be appropriately reduced or the cooling system should be started to avoid material deterioration caused by excessive temperature rise.
- Establish a standardized equipment maintenance system, including daily cleaning of equipment surfaces and material contact parts, monthly inspection of frequency converters and control systems, and quarterly replacement of lubricating oil and seals, to ensure the long-term stable operation of the equipment.
Summary
The application of the combined system of high-speed disperser and high-shear emulsifier has fundamentally solved the long-standing problems of poor dispersion effect, unstable emulsification, low production efficiency and large quality fluctuation in the production process of the facility. By means of process optimization and reasonable equipment matching, the system has realized the efficient integration of dispersion and emulsification functions, significantly improved product quality and production efficiency, and reduced operational costs.
For production scenarios involving multi-component mixed materials, the combined use of high-speed dispersers and high-shear emulsifiers can give full play to their respective advantages, make up for the limitations of single equipment, and form a more efficient and stable processing mode. Through continuous optimization of process parameters and standardized equipment operation and maintenance, the combined equipment system can provide reliable technical support for the sustainable development of the facility, help the facility improve production competitiveness, and adapt to the increasingly strict quality requirements of the market.
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