The use of agricultural product dryer brings many advantages such as helping to preserve agricultural products for a longer time, preventing spoilage, and being able to dry many different types of agricultural products,…
Overview of Agricultural Product Dryer
Definition of agricultural product dryers
An agricultural product dryer is a device specifically designed to remove moisture from agricultural products such as grains, seeds, fruits, vegetables, and other agricultural products. The main purpose of the drying process is to reduce the water content in the product for long-term storage, reduce the shipping volume, and prepare for the next processing process.
Agricultural product dryers work by creating an environment with controlled temperature and humidity, allowing the water in the product to evaporate efficiently while maintaining the quality and nutritional value of agricultural products.
Common types of agricultural product dryers
Batch dryer:
- Operation in batches, suitable for small and medium-sized
- For example, cabinet dryer, tray dryer, silo dryer
Continuous dryer:
- Continuous operation, suitable for large scale
- For example, conveyor dryers, tower dryers, rotary drum dryers
Solar Dryer:
- Using solar energy for drying, eco-friendly
- Can be knockout or indirect
Heat Pump Dryer:
- Using heat pump technology to reuse heat, save energy
- Suitable for high-temperature sensitive products
Fluidized bed dryer:
- Use hot air to create a “boiling” layer of seeds, drying evenly
- Suitable for granules and small granular products
Microwave dryer:
- Using electromagnetic waves for drying, short drying time
- Suitable for some special agricultural products
Advantages of using agricultural product dryer

- Extend storage time, and reduce damage caused by microorganisms
- Preserve the quality and nutritional value of the product
- Reduce shipping volume, save logistics costs
- Allows preservation of products for sale at times of high prices
- Humidity control, consistent quality assurance
- Allows for high-volume drying, meeting the needs of industrial-scale production
- Adjustable drying parameters (temperature, time, wind speed)
- Flexibility in adjusting the drying process for each type of product
- Reduced labor requirements compared to traditional drying methods
Structure of agricultural product dryer
Drying chamber – the main component of the agricultural product dryers
Structure:
- Usually in the form of a rectangular box or cylinder
- Made from heat-resistant and corrosion-resistant materials such as stainless steel
- There is insulation to reduce heat loss to the environment
Dimensions:
- Varies according to capacity and dryer type
- It can be from a few cubic meters to hundreds of cubic meters
Internal layout:
- There are trays or conveyors for placing agricultural products
- Designed to ensure a steady flow of hot air throughout the product
- There are feed and discharge outlets
Specification:
- Capable of withstanding high pressures and temperatures
- Designed for easy cleaning and maintenance
- There is a closed-door system to prevent outside air from entering
Heat supply system in agricultural product dryers

Heat source:
- Resistance: Uses electricity to generate heat
- Fuel burning: Uses gas, oil, coal, or biomass
- Heat Pump: Uses the principle of heat pump to generate and reuse heat
- Solar Energy: Uses direct or indirect solar radiation
Heat exchanger:
- Helps transfer heat from the heat source to the drying air
- Usually made of metals with high thermal conductivity such as copper or aluminum
Heat pipes:
- Distribute hot air evenly throughout the drying chamber
- Insulated to reduce losses
Thermostatic system:
- Fuel flow control valve (for combustion system)
- Power Controller (for electrical systems)
Fan and ventilation system of agricultural product dryer
Main fan:
- Creating convection airflow in the drying chamber
- Usually a centrifugal fan or axial fan
- Capacity varies according to dryer size
Auxiliary fans:
- Supports gas circulation in specific areas
- Helps to homogenize temperature and humidity
Air hose:
- Distribute hot air evenly throughout the drying chamber
- Adjustable to optimize airflow
Moisture discharge system:
- Remove moist air from the drying chamber
- Includes exhaust fan and exhaust pipe
Air filter:
- Filters dust and impurities from the inlet air
- Protection of the product and internal parts of the dryer
Controllers and sensors in agricultural product dryer
Central controller:
- Usually PLC (Programmable Logic Controller) or industrial computer
- Control and monitor the entire drying process
- Storage of drying programs for different agricultural products
User interface:
- Display screen (LCD or touch)
- Keyboard or buttons for input and adjustment
Temperature sensor:
- Temperature measurement in the drying chamber and in critical locations
- Usually use a thermistor sensor or thermocouple
Humidity Sensor:
- Measuring the humidity of the air in the drying chamber
- Measuring the moisture content of the product (some advanced dryers)
Flow sensors: Measure the speed and air flow in the system
Pressure Sensor: Pressure monitoring in the drying chamber (especially important in vacuum dryers)
Safety system:
- Fire and smoke detection sensors
- Safety switches for doors and moving parts
Data recording system:
- Storing information about the drying process
- Allows for later data retrieval and analysis
All of these components work together to create a complete agricultural dryer that has precise control over the drying process, ensuring product quality and energy efficiency.
The principle of operation of the agricultural product dryer

Agricultural product dryers work on the principle of blowing continuous convection heat to reduce the water content in agricultural products to the desired level. This process includes the following key steps:
Heat generation process in agricultural product dryer
The heat required for the drying process is provided by various heat sources such as:
- Fossil fuels: coal, firewood, oil, gas,…
- Power: use resistance rods or heat pumps.
- Solar energy: use solar cells to generate electricity.
The heat is transferred to the drying medium through the following methods:
- Transmission: through the walls, walls of the drying chamber.
- Convection: through the circulation of hot air.
- Radiation: infrared.
Hot air circulation mechanism in agricultural product dryer
- The blower plays an important role in creating a continuous flow of hot air in the drying chamber
- This hot air will come into direct contact with agricultural products, evaporating water from the surface of agricultural products
- The speed and direction of the hot air flow affect the drying efficiency and product quality.
The process of removing moisture from agricultural products using an agricultural product dryer
- The water in agricultural products diffuses from the inside to the surface due to the difference in water vapor pressure.
- The water on the surface of agricultural products evaporates into the hot air stream. Steam is drawn out of the drying chamber by means of a ventilation system.
- The drying process takes place continuously until the water content in the agricultural products reaches the desired level.
Temperature and humidity control in agricultural product dryer
The temperature and humidity in the drying chamber need to be strictly controlled to ensure product quality. Automatic or manual control systems are used to regulate temperature and humidity. Some factors to consider when controlling temperature and humidity:
- The type of agricultural products that need to be dried.
- The initial water content of agricultural products.
- Desired product quality.
- Ambient conditions.
In addition, a number of other factors also affect the performance of agricultural product dryers:
- The size and shape of the drying chamber.
- The amount of air circulating in the drying chamber.
- How to arrange agricultural products in the drying chamber.
Please contact us immediately to receive professional advice and optimal solutions for your needs.
Contact Information
VIETNAM TECHNOLOGY DEVELOPMENT AND TRANSFER JOINT STOCK COMPANY.
Office: VT09-BT02 – Xa La Urban Area – Ha Dong – Hanoi.
MST: 01 05 158 192
Website: https://vnatech.com.vn
Email: contact@vnatech.com.vn
Hotline: 0903 418 369 / 0977 550 085
ĐT: 024 668 3 261 / 098 311 7863