How can rice and wheat threshers ensure efficient threshing while minimizing grain breakage?
Publish Time: 2025-11-05
In modern agricultural production, combined rice and wheat harvesting and threshing operations place high demands on both efficiency and quality: rapid large-scale harvesting while maximizing grain integrity and minimizing breakage, cracks, and hidden damage. Grain breakage directly reduces marketable grade and milling yield, and can easily lead to mold growth during storage, affecting food safety. Rice and wheat threshers, through optimized threshing principles, controlled operating parameters, improved structural layout, and the introduction of intelligent control, seek a delicate balance between "high efficiency" and "low loss," achieving the ideal goal of "fast but not damaging, clean but not broken."
1. Optimized Threshing Method: From "Violent Impact" to "Flexible Separation"
Traditional threshers often use high-speed spiked rollers to violently impact crops, resulting in high threshing rates but severe grain breakage. Modern high-performance threshers generally employ a combination of axial-flow drum and concave sieve, or a dual-drum differential speed threshing structure. The former extends the threshing time and reduces instantaneous impact by having the crop spiral forward between the drum and the concave sieve; the latter uses a low-speed drum at the front for initial gentle threshing, followed by a high-speed drum at the rear to handle the difficult-to-thresh ears, achieving "graded threshing." Simultaneously, the drum teeth or grooved rods are designed with arc shapes, rubber coating, or adjustable inclination to reduce direct impact on the grains, instead relying on gentle forces such as rubbing and combing to separate the grains from the cob.
2. Precise Control of Key Parameters: Dynamic Matching of Speed, Gap, and Feed Rate
Threshing drum speed, the gap between the drum and the concave sieve, and the crop feed rate are the three core parameters affecting the breakage rate. Research shows that a higher drum speed is not always better—too high a speed can easily lead to grain breakage from impact, while too low a speed results in incomplete threshing. Modern threshers are equipped with continuously variable transmission (CVT) or intelligent speed control systems that automatically match the optimal speed based on the crop's moisture content and maturity. Meanwhile, the adjustable gap mechanism of the concave plates allows operators to fine-tune the gap according to crop type, preventing excessive compression of the grains. Furthermore, uniform and continuous feeding is crucial—overfeeding can lead to blockages and repeated impacts, while underfeeding causes damage from dry-firing. Advanced models are equipped with feed rate sensors and automatic adjustment devices to ensure stable material flow.
3. Collaborative Loss Reduction through Cleaning and Conveying Systems
Threshed grains undergo cleaning and conveying processes, both of which carry a risk of breakage. Modern threshers employ low-angle vibrating screens, flexible conveyor belts, or airflow-assisted cleaning to reduce grain drop height and frictional impact. For example, replacing traditional steep-slope slides with gentle-slope rubber belts significantly reduces grain impact damage; the cleaning fan speed is precisely controllable, preventing strong winds from blowing grains against the machine casing. Some high-end models also feature a grain recovery buffer zone to prevent grains from directly impacting hard baffles during high-speed airflow.
4. Intelligent Sensing and Adaptive Control: Towards Precision Threshing
With the development of intelligent agricultural machinery, some new threshers integrate moisture content sensors, visual recognition systems, and AI algorithms to monitor crop conditions in real time and automatically adjust drum speed, concave plate gap, and fan airflow. For example, when high moisture content of rice is detected, the system automatically reduces the speed and increases the gap to prevent brittle breakage of wet grains; if a large amount of impurities is detected, the cleaning intensity is increased. This "sensing-decision-execution" closed loop transforms the threshing process from "experience-driven" to "data-driven," ensuring efficient operation while controlling grain breakage rates below 1.5%.
High efficiency and low loss are not mutually exclusive but rather a core issue in the advancement of modern agricultural equipment technology. Through innovation in threshing mechanisms, precise parameter control, system synergy optimization, and intelligent control upgrades, Rice and Wheat Thresher has successfully found a golden balance between speed and gentleness. This not only improves the quality and economic benefits of grain harvesting, but also demonstrates the profound transformation of agricultural machinery from "usable" to "easy to use, intelligent, and green"—ensuring that every grain of rice and wheat can be safely stored, living up to the expectations of farmers.
