Fruit and Vegetable Cleaning Production Line

Production Line Functions

The main function of the fruit and vegetable cleaning production line is to realize the transformation from "rough goods" harvested from the field to "clean goods" that can be sold directly or further processed. Its core functions include:

1. Material Conveying and Lifting: Achieving the continuous flow of fruits and vegetables between different process sections through mechanical conveying devices, reducing manual handling and ensuring production continuity.
2. Impurity Separation and Pre-cleaning: Utilizing vibration sorting or wind power separation technology to initially remove large impurities such as stones, mud, and dead leaves mixed in the raw materials, and conducting preliminary screening.
3. Deep Cleaning and Decontamination: Based on the physical characteristics of fruits and vegetables (such as surface roughness and morphology), using methods like air bubble tumbling, brush friction, and high-pressure spraying to remove adhered mud, insect eggs, and some microorganisms.
4. Pesticide Degradation and Sterilization: Using ozone oxidation, ultrasonic cavitation, or chemical agents (such as sodium dichloroisocyanurate) soaking to effectively degrade pesticide residues on the surface of fruits and vegetables, kill pathogenic bacteria and viruses, ensuring food safety.
5. Blanching and Cooling (Optional): For some vegetables (such as leafy vegetables and beans), short-term high-temperature hot water treatment (95°C-100°C) is used to inactivate enzymes, prevent browning, maintain color, and kill some heat-resistant bacteria, followed by rapid cooling to room temperature.
6. Dewatering and Drying: Using centrifugal force or air knife technology to remove surface free water from fruits and vegetables, preventing bacterial growth caused by moisture accumulation during subsequent storage and extending the shelf life.
7. Automatic Packaging: Automatically weighing, filling (such as nitrogen or carbon dioxide flushing), or vacuum packaging the treated clean vegetables to isolate external pollution and upgrade product grade.

Equipment Composition and Technical Overview

A complete fruit and vegetable cleaning production line is composed of multiple functional modules. The specific configuration is determined according to the processing object (leafy vegetables, root vegetables, or mixed types) and production capacity requirements.

Main Equipment List

1. Lifting Conveyor: Used for the vertical lifting and horizontal transfer of raw materials, usually made of food-grade stainless steel mesh belt or chain plate structure.
2. Pre-treatment Equipment: Mainly includes vibration sorting machines and manual picking platforms, used to remove impurities and rotten fruits.
3. Core Cleaning Equipment: Mainly includes air bubble cleaning machines, brush cleaning machines, and high-pressure spray machines.
4. Deep Treatment Equipment: Mainly includes ozone generators, ultrasonic cleaning tanks, or electrolyzed water disinfection tanks.
5. Blanching and Cooling Equipment: Mainly includes belt-type blanching machines and multi-stage cooling tanks.
6. Dewatering Equipment: Mainly includes centrifugal dewatering machines, vibration dewatering machines, or air knife dryers.
7. Packaging Equipment: Mainly includes automatic weighing machines and vacuum/modified atmosphere packaging machines.

Technical Overview

1. Air Bubble Flipping and Brush Friction Cleaning Technology: This is the basic cleaning technology of the production line. The air bubble cleaning machine uses a high-pressure fan to pass air through a bottom pipeline or air pipe to generate a large amount of air bubbles. The air bubbles rupture upon rising, creating a micro-jet and impact effect, causing the fruits and vegetables in the water to produce irregular tumbling motion, thereby peeling off surface mud and dirt. Combined with mesh belt conveying, the fruits and vegetables overflow from the water to complete the cleaning and move to the next station. For root vegetables with harder skins or irregular shapes (such as potatoes and carrots), a rotating brush cleaning technology is used. The equipment contains multiple food-grade brush rollers. Driven by a motor, the brushes rotate relative to the fruits and vegetables to create friction. With the assistance of high-pressure spray water, mud and surface defects in the crevices can be effectively removed, resulting in a very high cleanliness.
2. Ozone Oxidation and Ultrasonic Assisted Sterilization Technology: To address pesticide residues and microbial exceedance issues, the production line integrates ozone technology. An ozone generator converts oxygen in the air into ozone (O3), which dissolves into the cleaning water through a gas-liquid mixer. Ozone has an extremely strong oxidation ability, capable of rapidly decomposing organic phosphorus pesticide molecules on the surface of fruits and vegetables, while destroying the cell membranes of bacteria and viruses, achieving sterilization and disinfection purposes. It decomposes into oxygen without chemical residues afterwards. For high-end ready-to-eat vegetables (such as salad vegetables), it is often combined with ultrasonic cleaning technology. Ultrasonic waves produce a "cavitation effect" in the liquid, forming countless tiny vacuum bubbles. The high-temperature and high-pressure impact waves generated by the instantaneous closure of these bubbles can penetrate deep into the microscopic pores of the fruit and vegetable skin, peeling off and killing adhered microorganisms, ensuring thorough cleaning without dead angles.
3. Multi-stage Blanching and Rapid Cooling Technology: This technology is mainly used for color protection and preservation of fresh-cut vegetables. The blanching machine uses steam or electric heating to accurately control the water temperature between 95°C and 100°C. Fruits and vegetables pass through the tank body on a mesh belt for 45-50 seconds. The short-term high-temperature treatment rapidly inactivates polyphenol oxidase to prevent browning at the cut, while softening the tissue to improve texture. After blanching, the fruits and vegetables immediately enter a multi-stage cooling tank (usually in three stages, with temperature gradually dropping from 60°C to room temperature). Through chain plate transmission and forced cooling, residual heat is prevented from over-softening the product, maintaining its crisp texture.4. Variable Frequency Control and Automated Integration Technology: The entire production line is composed of a PLC (Programmable Logic Controller) and a touch screen to form an automated control system. Operators can set parameters such as conveyor belt speed, cleaning time, water temperature, and ozone concentration according to the physical characteristics of different fruits and vegetables (such as the tenderness of leafy vegetables and the hardness of root vegetables). The system features fault alarm diagnosis, emergency protection, and production data recording functions, realizing "unmanned" or "few-person" operation from raw material input to finished product output, greatly improving production efficiency and reducing labor intensity.