Fresh Stevia Leaf Rotary Kiln Dryer

1. Equipment Design Conditions:

1. Material Conditions:

Material Name: Fresh Stevia Leaves

Initial moisture content: 70–75%; calculated as 75%.

Final moisture content: 10–12%; calculated as 10%.

Processing capacity: 1200kg/h;

Wet material temperature: Room temperature (θ1=20°C)

Hot air temperature: t1=200℃;

Outlet air temperature: t2=80℃;

Material temperature after drying: θ2 = 65～70℃;

Ambient air temperature parameters: air temperature is t0=20°C, air moisture content is d0=0.01 kg water/kg dry air.

The specific heat of the absolutely dry material is set as: Cs = 0.4 kcal/kg·°C

Heating method: Indirect combustion (bagasse, straw, rice husk) hot air furnace

Power Supply: Voltage 380V±10V, 50Hz;

II. Working Principle:

After the wet material is fed into one end of the dryer, it is evenly distributed and dispersed within the cylinder under the agitation of uniformly arranged lifting plates. The material comes into contact with co-current hot air, accelerating the driving forces of heat and mass transfer during drying. Throughout the drying process, under the influence of the inclined lifting plates and the hot airflow, the material moves in a controlled manner to the other end of the dryer, where it is discharged as finished product through a star-shaped discharge valve. The exhaust gas is emitted into the atmosphere by an induced draft fan.

Although the rotary drum dryer is one of the oldest drying equipment, it is still widely used in fields such as metallurgy, building materials, and chemical engineering. This rotary kiln adopts a concurrent flow drying method.

Features:

1. High production capacity, capable of continuous operation;

2. Simple structure, easy to operate;

3. Fewer malfunctions and lower maintenance costs.

4. Wide range of applications: it can be used to dry granular materials and is also highly effective for materials with strong adhesion.

5. High operational flexibility, allowing for significant fluctuations in production output without compromising product quality.

6. Easy to clean;