granular lotus root starch fluidized bed dryer

I. Working Principle and Structural Design Features

Working Principle

The material, after granulation, enters the fluidized bed feed inlet and then into the dryer. Purified, heated, and pressurized air is blown in through various air outlets at the bottom of the fluidized bed, passing through the mesh plates and contacting the material layer. This fluidizes the material within the bed, causing rapid and intense heat and mass transfer upon contact with the hot air. The moisture in the material is quickly vaporized. The material passes through eight drying chambers sequentially from the feed end to the discharge end, completing the drying and cooling process until the product reaches qualified material standards.

As drying progresses, the moisture content of the material gradually decreases. During vigorous boiling, fine powder is easily generated from the material particles. This fine powder is collected and recovered through the dust collector bags inside the fluidized bed. The humid air is discharged outdoors through the top exhaust duct and induced draft fan.

Structural Design and Features

1. A fixed fluidized bed dryer, i.e., a boiling bed dryer, is adopted, with an appropriate bed height to ensure sufficient drying time for the material (the residence time of the material in the bed is one of the key factors affecting the system's capacity). 1. Drying time is 15-30 minutes.

2. The equipment uses a built-in bag filter; simultaneously, the cross-sectional area and height of the fluidized bed settling chamber are increased to reduce air velocity.

3. The fluidized bed main unit structure is designed according to the drying characteristics of the material;

-Increasing the height and cross-sectional area of ​​the expansion section reduces the amount of fine powder carried out in the exhaust gas.

----The specific gravity of wet and dry materials differs, requiring different air pressures and fluidization velocities in different drying chambers. The closer to the wet material feed end, the higher the required fluidization velocity and air pressure; the closer to the discharge end, the lower the fluidization velocity and air pressure.

4. Each chamber's air inlet is equipped with an air regulating valve to adjust the airflow to each chamber.

II. Process Parameters

1. Material Name: Granular Lotus Root Starch

2. Finished Product Capacity: 400 kg/h

3. Finished Product Moisture Content: 8%

4. Feed Moisture Content: 15-20%

5. Heat Source: Electric Heating

6. Material Collection Method: Main Unit

7. Material: Material Contact Stainless Steel 304, the rest is made of carbon steel

III. Material Balance

Finished Product Output: 400 kg/h

Moisture Evaporation Rate: 60 kg/h

Processing Capacity: 460 kg/h

Heat Balance:

Inlet Air Temperature: 120℃, Outlet Air Temperature: Approximately 70-75℃, Ambient Temperature: 20℃

1. Heat Required for Moisture Evaporation: 36432 kcal/h

2. Heat Required for Material Heating: 8000 kcal/h

3. Dry Air Consumption: 4260 kg/h

4. Exhaust Gas Volume: 4310 m³/h

Based on the above calculations and material characteristics, one XF-0.5X4m(B) fluidized bed dryer is selected.

IV. Main Calculation Parameters of the Equipment:

1. Equipment Name: Fluidized Bed Dryer

2. Equipment Model: XF-0.5X4(B)

3. Inlet Air Temperature: 120℃

4. Outlet Air Temperature: 70-75℃ (Adjustable)

5. Output: 400kg/h

6. Heating Method: 120kW Electric Heating

7. Compressed air for the bag filter needs to be provided by the user. Compressed air consumption: 0.2-0.3m³/min, rated exhaust pressure: 0.4-0.6MPa (oil and water removal)

8. Installed Power: ~15kW (excluding electric heating)