The Camellia oleifera seed dryer, also known as the tea seed, blooms in October and its fruits mature between October of that year and October of the following year. The tea oil extracted from the Camellia oleifera seeds is a type of edible oil, containing over 90% of unsaturated fatty acids and free of erucic acid. It is more resistant to storage and less prone to rancidity than other edible oils.

Post-harvest Camellia oleifera seeds with excessive moisture content tend to have soft shells that are difficult to crack, high plasticity, and easily leak during pressing. Therefore, it is necessary to dry these high-moisture seeds with a drying machine to ensure their moisture content does not exceed 13% for effective shell removal and kernel pressing. The Camellia oleifera seed drying machine plays a crucial role in oil extraction processing, as the quality of drying directly impacts the oil yield.

How to roast oil tea seeds with an air-source heat pump oil tea seed dryer to achieve shell crisp and kernel soft, and high oil yield? Based on the actual process of drying oil tea seeds with an air-source heat pump oil tea seed dryer, the author summarizes five reference steps for parameter settings of the oil tea seed dryer.

Step 1: Maintain a temperature of 55°C, no longer than 2 hours, only heat without dehumidifying, ensuring the camellia seeds are heated evenly to achieve an average consistent temperature. As the oil camellia seed temperature rises, its surface vapor pressure also increases, and the rate of water vaporization accelerates rapidly.

Step 2: Begin heating and dehumidifying, maintaining a temperature of 60°C, reducing humidity from the initial 75% to 55% over approximately 6 hours. The rate at which moisture on the oil tea seeds diffuses into the surrounding medium increases, resulting in a direct decrease in moisture content.

Step 3: Maintain a constant drying temperature of 60°C, using a continuous dehumidification method to reduce humidity to 40% over a period of 4 hours. This ensures that the vapor pressure of water on the surface of the camellia oleifera seeds is in a dehumidification state corresponding to their current temperature.

Step 4: Reduce humidity to 30%, increase temperature by 3℃ from Step 2, duration 4 hours, with no change in drying speed.

Step 5: Reduce humidity to 20%, maintain the temperature constant, for 4 hours. The air humidity should be at 20%, with the camellia seed humidity around 10-12%. Complete the drying process.