Application of PLC Control Technology in Deep Processing of Peanuts
Role and Implementation of Automation Control Technology in Key Processes such as Peanut Slicing, Dicing, Peeling, and Grinding into Paste
Introduction: The Demand for Automation in Deep Peanut Processing and the Value of PLC Technology
As a globally important oilseed and cash crop, the deep-processing industry for peanuts faces multiple challenges in production efficiency, product quality, and safety standards. Traditional peanut processing relies on manual operations and empirical judgment, leading to low efficiency, inconsistent quality, and hygiene and safety hazards. With the advancement of automation in the food industry, Programmable Logic Controller (PLC) technology is becoming the driving force behind automation in deep peanut processing.
Deep processing of peanuts includes multiple processes such as cleaning, grading, roasting, slicing, dicing, peeling, and grinding into paste. Each process has specific requirements for control accuracy, response speed, and reliability. PLC, with its high reliability, strong anti-interference capability, flexible programming, and easy maintenance, demonstrates unique advantages in the field of peanut processing. According to statistics, automated peanut processing lines using PLC control can increase production efficiency by 40-60%, improve product qualification rate by 25-35%, and reduce labor costs by 50-70%.
I. Fundamentals of PLC Control Technology and Its Suitability for Peanut Processing
1.1 Basic Principles of PLC Technology
Programmable Logic Controller (PLC) is a digital operation system specially designed for industrial environments. It uses programmable memory to store instructions that perform operations such as logic, sequencing, timing, counting, and arithmetic, and it controls various mechanical equipment via digital or analog input/output. A PLC system consists of a Central Processing Unit (CPU), memory, input/output interfaces, power supply, and programming device, among other components.
1.2 Special Requirements of Peanut Processing for Control Systems
Deep processing of peanuts involves complex material properties, tightly coupled processes, and high hygiene requirements, which pose special challenges for control systems. These include adaptive control for material non-uniformity, multi-process协同 control, hygiene and safety requirements, energy consumption control, and rapid fault handling.
1.3 Typical Configuration of PLC Systems for Peanut Processing
The typical configuration of a PLC system for deep peanut processing includes a controller (such as Siemens S7-1500 or Mitsubishi FX5U), input modules (digital and analog), output modules (digital and analog), and communication networks (PROFINET, Ethernet/IP, or CC-Link IE).
II. Precise Control of PLC in the Peanut Slicing Process
2.1 Process Characteristics and Control Requirements for Peanut Slicing
Peanut slicing is a key process in deep processing, directly affecting the product’s sensory quality and subsequent processing performance. Ideal peanut slices should have uniform thickness, neat edges, and a low breakage rate. Traditional slicers rely on mechanical adjustments, making it difficult to adapt to variations in peanut particle size and resulting in unstable slicing quality.
2.2 Hardware Configuration of PLC Slicing Control System
The core hardware of a PLC control system for peanut slicing includes a PLC main control unit, a servo drive system, a sensor network, a Human-Machine Interface (HMI), and safety modules. These components work together to achieve precise control of slice thickness and to monitor quality.
2.3 PLC Slicing Control Program Design
The PLC slicing control program uses a structured design, including a main control program, thickness control function blocks, alarm handling programs, etc. Precise control of slice thickness is achieved through PID control algorithms, with thickness control accuracy reaching ±0.1mm.
2.4 Slicing Quality Control and Optimization
The PLC system realizes real-time monitoring and adaptive adjustment of slicing quality by integrating machine vision and force sensors. Typical performance indicators include slice thickness control accuracy ±0.1mm, slice breakage rate ≤3%, slice合格率 95-98%, and maximum slicing speed 1200 slices/minute.
III. Multi-dimensional Control of PLC in Peanut Dicing Process
3.1 Process Characteristics of Peanut Dicing
Peanut dicing is the process of cutting peanut kernels into cubes or cuboids, widely used in salad ingredients, snack production, and other applications. Dicing quality requires uniform size, distinct edges, and minimal debris. Traditional dicing machines struggle to ensure consistency in multi-dimensional cutting, while PLC control systems achieve high-precision three-dimensional cutting by coordinating the motion of multiple cutting axes.
3.2 Multi-axis Synchronization Control Technology
Peanut dicing requires high-precision synchronized motion of three cutting axes. PLC meets this requirement through high-speed counters and multi-axis motion-control modules. Key technologies include electronic gear function, cam curve control, position synchronization control, adaptive speed adjustment, and tool wear compensation.
3.3 Intelligent Adjustment of Dicing Size
To accommodate different product requirements, the PLC system enables rapid adjustment of dicing sizes, including fine dice (3×3×3mm), standard dice (6×6×6mm), coarse dice (10×10×10mm), and rectangular dice (5×5×10mm), among others.
IV. Adaptive Control of PLC in Peanut Peeling Process
4.1 Challenges in the Peanut Peeling Process
Peanut peeling is a key technical link in deep processing, directly affecting product taste and appearance. Traditional peeling methods include dry friction peeling, wet浸泡 peeling, and infrared heating peeling, but they suffer from low peeling rate, high kernel damage rate, and high energy consumption. PLC control systems achieve efficient, low-damage peeling by precisely controlling peeling parameters.
4.2 PLC Control for Dry Friction Peeling
Dry friction peeling uses the friction between peanuts and the container wall to remove the red skin. The PLC control system enables functions such as precise speed control, friction pressure adjustment, temperature monitoring and control, peeling time optimization, and kernel damage rate control.
4.3 PLC Control System for Wet Peeling
Wet peeling removes the red skin through浸泡 and gentle friction, suitable for peanut products requiring high integrity. The PLC control system enables control of浸泡 temperature,浸泡 time, pH monitoring, water flow, and moisture.
4.4 Peeling Quality and Efficiency Optimization
PLC-controlled peanut peeling systems can achieve excellent performance: peeling rate ≥98%, kernel damage rate ≤1.5%, processing capacity 500-1000kg/h, and energy consumption reduction of 30-40%.
V. Closed-loop Control of PLC in Peanut Grinding Process
5.1 Process Characteristics of Peanut Butter Production
Peanut grinding into paste is the process of grinding roasted peanut kernels into a paste-like product, resulting in a fine, uniform, and stable product. Traditional grinding processes rely on operator experience, making it difficult to ensure batch consistency. PLC control systems ensure stable, high-quality peanut butter production by precisely controlling grinding parameters.
5.2 PLC Control Strategy for the Grinding Process
Key PLC control strategies for peanut grinding include multi-stage grinding control, temperature gradient control, power monitoring and optimization, automatic recipe execution, and foreign object detection and handling. Through these strategies, precise control of peanut butter particle size, viscosity, temperature, and flavor is achieved.
5.3 Closed-loop Quality Control of Peanut Butter
The PLC system, by integrating various online detection instruments, enables real-time monitoring and automatic adjustment of peanut butter quality. Monitoring indicators include particle size distribution, viscosity, temperature, moisture content, and color, with control accuracies of ±2 μm for D90, ±50 cP for viscosity, ±1 °C for temperature, ±0.2% for moisture content, and ΔE ≤ 1.5 for color.
5.4 Energy Consumption Optimization in the Grinding Process
Peanut grinding is a process with relatively high energy consumption. The PLC system achieves excellent performance through optimized control strategies: unit energy consumption reduced by 25-35%, batch consistency ≥99.5%, production capacity of 800-1500kg/h, and average particle size ≤ 15 μm.
VI. PLC System Integration and Intelligent Management of Production Lines
6.1 Full-line PLC Integration in Deep Peanut Processing
Modern deep peanut processing lines consist of multiple processes. PLC systems not only control individual equipment but also achieve协同 work and data sharing among all line equipment. Through industrial Ethernet and fieldbus technologies, a unified control platform is built, including four layers: management layer, control layer, device layer, and field layer.
6.2 Data Acquisition and Monitoring System (SCADA)
PLC-based SCADA systems enable comprehensive monitoring and data management of the deep peanut processing process. Main functions include production process visualization, data recording and analysis, alarm management, report generation, and remote monitoring.
6.3 Quality Traceability System
The PLC system, combined with barcode/RFID technology, provides full-process quality traceability across deep peanut processing, including raw material batch management, production process recording, quality inspection data recording, product identification, and traceability queries.
6.4 Energy Management System
The PLC system integrates energy management functions, enabling monitoring and optimization of energy consumption in deep peanut processing. This includes monitoring and节能 control of electricity, heat, water consumption, and compressed air, which can reduce energy consumption by 15-25%, 20-30%, 40-50%, and 25-35%, respectively.
VII. Development Trends of PLC Technology in Peanut Processing
7.1 Integration of Intelligence and Artificial Intelligence
Future PLC systems will deeply integrate with artificial intelligence technologies, enabling intelligent upgrades in deep peanut processing. This includes machine learning for optimized control, visual intelligent detection, predictive maintenance, adaptive recipes, and intelligent production scheduling.
7.2 Industrial Internet of Things (IIoT) Integration
As a key node in the Industrial Internet of Things, PLC will enable comprehensive connectivity between peanut processing equipment and cloud platforms, including device interconnection, cloud platform analysis, remote operation and maintenance, and supply chain coordination.
7.3 Modular and Flexible Design
To adapt to market demands for multiple varieties and small batches, PLC control systems will become more modular and flexible. Features will include configurable hardware, programmable software, quick changeover, scalable architecture, and open interfaces.
7.4 Enhancement of Safety and Reliability
As automation levels in deep peanut processing increase, safety and reliability requirements for PLC systems are also rising. Target performance includes system availability ≥99.9%, mean time between failures ≤1 hour/year, Safety Integrity Level SIL3, and protection rating IP67.
Conclusion: PLC Technology Promotes Industrial Upgrading in Deep Peanut Processing
As the core of industrial automation, PLC control technology offers immense application value in deep peanut processing. From precise motion control in slicing and dicing to optimization of process parameters in peeling and grinding to coordinated management and data integration of full-line equipment, PLC technology comprehensively enhances production efficiency, product quality, and process controllability in deep peanut processing.
With the development of Industry 4.0 and intelligent manufacturing, PLC technology will become more intelligent, networked, and flexible, deeply integrating with new technologies such as artificial intelligence, the Internet of Things, and big data, driving deep peanut processing towards higher levels of automation and intelligence. For peanut processing enterprises, actively applying PLC control technology is not only a necessary means to improve competitiveness but also an inevitable choice to adapt to the development trends of the food industry.
In the future, as PLC technology continues to advance and costs decrease, small and medium-sized peanut processing enterprises will also be able to enjoy the benefits of automation. By adopting modular, standardized PLC solutions, the overall automation level of the deep peanut processing industry will be comprehensively enhanced, providing strong technical support for the high-quality development of China’s peanut industry.
