Temperature control is a critical technical priority in the fine grinding of pea and pulse protein, especially when targeting particle sizes below D90 20μm. During ultra-fine pulverization, mechanical impact, shear and friction convert large amounts of mechanical energy into heat. Without targeted thermal management, accumulated heat can denature heat-sensitive plant proteins, degrade native nutritional and functional properties, cause material sticking and blockages, and even elevate dust safety risks. For dry fractionation processes, effective temperature control is the key to achieving ultra-fine particle size while preserving full protein functionality. Built on nearly 20 years of ultra-fine grinding and air classification expertise, JACAN delivers a full-chain temperature control strategy spanning equipment design, process engineering and intelligent regulation, ensuring low-temperature, gentle and efficient plant protein processing.
1. Understand Heat Generation in Fine Protein Grinding
Effective temperature management begins with identifying the sources and risks of heat buildup in fine grinding operations.
- Mechanical energy conversion: The impact and shear forces applied by grinding rotors to break down pea cotyledon cells convert most input energy into thermal energy. The finer the target particle size — such as D90 < 20μm — the more breakage cycles and longer retention time the material requires, amplifying heat generation.
- Ineffective friction heat: Unremoved fibrous hulls, uneven feed rates and over-grinding all create extra friction and unnecessary heat input.
- Quality and operational risks: Pea protein is inherently heat-sensitive. Prolonged exposure to elevated temperatures causes protein denaturation, reducing solubility, emulsification and foaming properties that are critical for end-product functionality. Heat can also cause moisture migration, material sticking to chamber walls, pipeline blockages and reduced production stability.
2. Optimized Grinding Mechanism: Reduce Heat at the Source
The most effective thermal strategy is to minimize heat generation in the first place, rather than only removing heat after it forms.
- Precision, high-efficiency breakage: JACAN’s ultra-fine grinding systems use an optimized impact-shear composite breakage mechanism calibrated to the cellular structure of pea and pulse materials. It achieves cell disruption and particle size reduction in a short residence time, efficiently releasing intact protein and starch bodies without subjecting material to unnecessary repeated grinding. This drastically cuts redundant heat generation at its source.
- Low-friction structural design: The grinding chamber features streamlined internal geometry and high-precision assembly to reduce wall friction for both airflow and material. Core wear components are manufactured from low-friction, high-wear materials that maintain consistent breakage efficiency over long operating hours, preventing a rise in frictional heat as parts degrade.
- Gentle de-agglomeration: Integrated gentle de-agglomeration breaks up particle agglomerates without damaging protein molecular structure, avoiding the extra temperature rise caused by aggressive shear forces.
3. Process Airflow Cooling: Continuous Heat Removal
For dry grinding and fractionation systems, process airflow is the primary and most efficient cooling medium, providing continuous heat removal throughout the production line.
- Full-process air heat exchange: JACAN’s integrated grinding-classification circuit conveys material via continuous process airflow. As ambient process air flows through the grinding chamber, it absorbs heat from both the material and equipment surfaces, carrying thermal energy out of the system continuously to maintain temperatures within a safe, protein-friendly range.
- Precision air-to-solid ratio tuning: The multi-parameter control system optimizes the ratio of air velocity to feed rate. This ensures sufficient air volume to absorb heat per unit of material, avoiding both insufficient cooling from low airflow and wasted energy plus excess friction from excessive airflow.
- Uniform flow field design: The internal flow fields of the grinding chamber and air classifier are hydrodynamically optimized to eliminate local eddies and stagnant zones, preventing localized heat buildup and maintaining uniform temperatures across the entire system.
4. Closed-Loop Grinding & Classification: Minimize Heat Exposure Time
Over-grinding is one of the largest contributors to unnecessary heat and protein damage. A closed-loop grinding and classification circuit eliminates this issue by removing fine particles immediately once they meet specification.
- Instant discharge to avoid over-processing: Particles that reach the target fineness are immediately carried by airflow into the high-precision air classifier, separated as finished product and discharged from the system. Oversized particles are automatically returned to the grinding mill for further size reduction. This closed-loop configuration prevents qualified fine powder from undergoing additional grinding, greatly shortening the heat exposure time of protein particles and reducing total heat output.
- Sharp cut-point calibration: Refined aerodynamic control sets an accurate separation cut-point, ensuring only particles meeting the size specification exit the circuit. This guarantees D90 < 20μm performance while maximizing discharge efficiency and minimizing residence time in the high-heat grinding zone.
5. Multi-Parameter Intelligent Control: Stable Temperature Under Dynamic Conditions
Maintaining consistent temperature across continuous production runs and varying raw material batches requires real-time, automated process optimization.
- Real-time temperature monitoring: Temperature sensors installed at key points — including the grinding outlet and classifier inlet — track material and air temperature continuously, with data synchronized to the central control system.
- Automatic linked parameter adjustment: Powered by JACAN’s multi-parameter intelligent optimization platform, the system automatically adjusts feed rate, rotor frequency and air velocity when temperature drift is detected. For example, it can moderately reduce feed load, increase cooling airflow or optimize rotor speed to restore temperatures to the target range without compromising particle size or production output.
- Raw material adaptive tuning: For peas from different growing regions with varying hardness and moisture content, the system automatically matches optimal operating parameters to avoid grinding load fluctuations and temperature spikes, delivering stable thermal performance across continuous production.
6. Pre-Treatment Control: Reduce Grinding Load and Thermal Risk
Proper upstream pre-treatment lowers the thermal load on the grinding stage and creates more favorable conditions for temperature control.
- Precision dehulling and impurity removal: The upstream material cleaning and precision dehulling process removes high-fiber seed coats and hard foreign matter from raw peas. Fibrous fractions are hard to grind and generate high frictional heat. Processing clean, fiber-reduced cotyledon feedstock reduces grinding resistance, improves pulverization efficiency, lowers heat output and also boosts final protein purity.
- Feed moisture and temperature homogenization: Stable feed moisture and temperature prevent sticking and caking inside the grinding chamber and keep airflow cooling efficient. Pre-treatment homogenization ensures consistent feed conditions, creating a reliable baseline for downstream temperature control.
7. Balance Temperature Control and Protein Functionality
The ultimate purpose of temperature control is not only to hit a particle size target, but to preserve the commercial value of pea protein.
JACAN’s full-chain thermal control strategy maintains material temperatures below the protein denaturation threshold throughout fine grinding. This protects native protein structure, preserves solubility, emulsification, water-holding capacity and other key functional properties, and supports clean-label, chemical-free and sustainable plant protein production suitable for premium food and beverage applications.
Temperature control in fine grinding is a systematic engineering challenge, not a single-point adjustment. It requires coordinated optimization across grinding mechanism, airflow design, classification circuit, intelligent regulation and pre-treatment to simultaneously achieve ultra-fine particle size, high throughput and premium product quality.
With 19 years of deep expertise in ultra-fine grinding technology, a team of 150+ specialized R&D engineers and hundreds of technical patents, JACAN provides mature low-temperature fine grinding and dry fractionation solutions for plant protein processors worldwide. Our systems deliver D90 < 20μm performance while preserving full protein functionality, offering German and Japanese-grade quality at roughly one-third the cost. With delivery in 30–60 days, on-site installation and training, and 24/7 global technical support, we help customers build efficient, stable and high-quality plant protein production lines.
