The Main Components of Onion Drying Production Line

An onion drying production line is a continuous processing system composed of multiple modules working in coordination. Depending on the final product form (dried onion slices, onion powder, or seasoned onion granules), the line configuration may vary slightly, but the core components are basically the same. A complete onion drying production line typically includes the following six major modules:

1. Pre-treatment and Washing System

- Bubble washing machine / Brush roller washing machine: Uses high-pressure bubble turbulence or brush friction to remove mud, impurities, and part of the outer skin from the onion surface.

- Peeling equipment (optional depending on requirements): Uses a dry friction peeler or steam peeler to remove the outer dry skin of onions, reducing debris and bitterness generated during subsequent cutting.

- Manual sorting table: Removes rotten, diseased, or under-mature onions to ensure raw material quality.

2. Cutting System

- Onion slicing/dicing machine: Cuts onions into thin slices or square dice of specific sizes through high-speed rotating blades. The increased exposed area of cut onions facilitates rapid subsequent dehydration.

- Rinsing machine: Cut onions are prone to oxidative browning and need to be rinsed through a blanching machine to deactivate enzyme activity and maintain the finished product's color.

3. Air Drying System

- Cold air blower: Uses cold air to remove a large amount of free water from the surface of onion slices/dice. This step can significantly reduce energy consumption in the subsequent drying stage and shorten drying time.

- Spreading device: Evenly spreads the air-dried onions onto the dryer's mesh belt to ensure consistent material layer thickness and avoid uneven drying.

4. Drying System (Core Equipment)

- Multi-layer mesh belt dryer: Usually composed of 3–6 layers of stainless steel mesh belts, with hot air vertically penetrating the material layer. Onions turn and fall layer by layer along with the mesh belt, achieving continuous and uniform drying.

- Heat source system: Can choose air-source heat pumps, steam heat exchangers, natural gas burners, or biomass hot air furnaces to provide a stable heat source for the dryer.

- Intelligent temperature and humidity control system: Through the PLC control panel, set temperatures for different temperature zones in stages (usually controlled at 60°C–80°C), precisely control the moisture removal rhythm, and prevent onions from scorching or discoloring.

5. Cooling and Post-Processing System

- Cooling conveyor belt: Dried onions are at a high temperature and need to be cooled to room temperature through natural air or cold air conveyor belts to prevent condensation and mold after packaging.

- Screening/grading equipment: Removes debris, powder, and under-dried materials to ensure uniform finished product granularity.

- Metal detection and X-ray inspection (optional high-end configuration): Used for export or high-standard food processing to eliminate foreign object risks.

6. Packaging System

- Automatic weighing and packaging machine: For onion powder or small-pack onion granules, vertical packaging machines are used for quantitative filling (e.g., 500g, 1kg packs).

- Large bag packaging machine (bulk): Used for industrial raw materials, using large-size woven bags or paper bags for quantitative packaging.

- Sealing and coding equipment: Completes sealing and coding (production date, batch number, etc.), and finally warehousing.

A complete onion drying production line is essentially an assembly line of washing and peeling → cutting and color protection → dewatering and spreading → hot air drying → cooling and screening → weighing and packaging. If you plan to build this production line, you can contact us.