IQF (Fluidized Bed Freezer) This is a quick-freezing technology that uses a high-speed stream of cold air to blow through a conveyor belt and layers of products, causing them to move, separate, and freeze quickly. This technology is particularly suitable for small, loose products such as vegetables, sliced fruits, beans, corn, potatoes, and some types of seafood.
How does IQF fluidized bed technology work?
The fan circulates air through the cooling coil and then blows it across the conveyor belt onto the product layer. When the air velocity and pressure are sufficient, the individual items are lifted, vibrated, or moved relative to each other, creating a state similar to a "fluidized bed".
Cold air comes into contact with more product surfaces, resulting in faster heat exchange. Many systems divide the air into multiple zones: the initial zone separates the product, and the subsequent zone completes the freezing process.
Why aren't the products sticking together?
The airflow causes the individual particles to move and separate from each other, reducing the time the wet surfaces remain in contact. Simultaneously, the product surface is cooled and frozen very quickly, forming an initial layer of ice before the particles have a chance to clump together. This is a major advantage of the fluidized bed for products that need to maintain their loose IQF state after freezing.
Which products are suitable for IQF fluidized bed?
The most suitable product is Small, loose, and relatively uniform in size. and can move under the influence of air:
- Vegetable: Peas, corn kernels, diced carrots, potatoes, onions, and peppers. After freezing, the products are left as individual items, facilitating weighing, mixing, and automatic packaging.
- Fruit: Mango and pineapple cut into pieces, small pieces.
- Seafood: Small and medium-sized shrimp are required for loose IQF (Individual Quick Freezing) finished products. Shrimp differ from vegetables in shape, weight, and surface moisture, so the airflow speed, loading density, and freezing time must be adjusted; large or very wet shrimp should be tested in practice beforehand.
Products that are too large, too heavy, very soft, or have a very wet surface require testing to determine the appropriate airflow and ice load.
How does IQF fluidized bed differ from IQF mesh conveyor?
| Criteria | IQF mesh conveyor belt | IQF fluidized bed |
|---|---|---|
| Product status | Lying on the ice, moving with the ice. | Being lifted, vibrated, and moving relative to the ice. |
| Airflow | Circulate through or around the product | Penetrate the product layer with sufficient velocity and pressure to separate it. |
| Airflow and control systems | Simpler | More complicatedly, fans consume a significant amount of electricity. |
| Strengths | A diverse range of products, including larger items. | Freezing speed and separation with small, uniform products. |
The fundamental difference lies not in the type of ice, but in the interaction mechanism between the cold air stream and the product. See more mesh belt IQF freezer and overview What is IQF?.
What airflow rate is required for an IQF fluidized bed?
Actual flow rate depends on product type, size, weight, surface moisture content, band area, and product layer thickness.
| Example | Value |
|---|---|
| Product | Mangoes cut into 20 × 20 mm squares |
| Capacity | approximately 1,000 kg/h |
| Total recirculating airflow (preliminary design) | Approximately 90,000–130,000 m³/h, with a reference value of around 110,000 m³/h. |
| Air velocity in the product area | approximately 4–6 m/s |
In practical design, it is necessary to simultaneously check the flow rate, static pressure, resistance of the evaporator, conveyor belt, and product layer, so that the product moves correctly without being blown too hard or damaged.
What is the Freezing Retention Time for IQF fluidized bed?
- Small size, easy to create fluidized bed. (Peas, corn kernels, chopped vegetables, small fruits): usually a few minutes to about 10 minutes.
- Large, thick, or high-heat products (Broccoli, cauliflower, large pieces of mango, some seafood): about 10–20 minutes or longer.
The exact timing depends on size, inlet temperature, required core temperature, load density, air temperature, evaporation temperature, and air conditions. Thermal calculations should be combined with actual product testing.
How much electricity does an IQF fluidized bed consume?
Because it requires high airflow and pressure, Electric fans are a significant component. in total energy. Calculate the entire system (compressor, refrigerant pump, fan, conveyor, auxiliary), reference level approximately. 0.20–0.40 kWh/kg of product For optimal design and operation, adverse conditions may be higher.
Comparisons between systems should use indices. SEC = total electricity consumption (kWh) / weight of frozen product (kg), under the same product conditions and within the same equipment range.
Investment cost of IQF fluidized bed
There is no fixed price. Costs depend on capacity, ice size, freezer length, fan and evaporator system, materials, cleaning system, and level of automation. Separation is required. IQF device price with Total investment in refrigeration systems (compressor, receiver, pump, piping, refrigerant, electrical control, installation).
Compared to conventional IQF mesh, fluidized bed requires a more complex air distribution and control system; in return, with the right product, it offers advantages in freezing speed and product separation.
Conclude
IQF fluidized bed is suitable for vegetables, fruits, granular and pellet products, and some seafood that need to be kept loose. When choosing, consider product characteristics, airflow and pressure, freezing temperature, retention time, load on the ice, power consumption, ease of cleaning, and investment cost.
Tan Long designs and installs industrial refrigeration systems for freezing lines. Product and production data per shift are sent via... contact page Or call 0933 357 058 for advice on a suitable configuration.
Frequently Asked Questions about Fluidized Bed IQF
What is IQF fluidized bed?
This is a quick-freezing technology that uses a high-speed stream of cold air to blow through a conveyor belt and layers of products, causing them to move, separate, and freeze quickly. It is suitable for small, loose products such as vegetables, sliced fruits, and small shrimp.
Can IQF fluidized bed freezing be used to freeze shrimp?
Yes, especially for small and medium-sized shrimp that require loose IQF (Individual Quick Freezing) product. Adjustments to airflow speed, loading density, and freezing time are necessary; large or very wet shrimp should be tested beforehand.
What is the air velocity in the fluidized bed IQF?
The airflow is approximately 4–6 m/s in the product area. For example, IQF fluidized bed freezing of 1,000 kg/h of 20 × 20 mm mangoes requires a total airflow of approximately 90,000–130,000 m³/h.
How long does fluidized bed freezing take?
A few minutes to about 10 minutes for small items like peas and corn kernels; about 10–20 minutes or longer for larger items like broccoli and large pieces of mango.
How much electricity does an IQF fluidized bed consume?
The total energy consumption for a well-designed and operating system is approximately 0.20–0.40 kWh/kg of product. Fan power accounts for a significant portion due to the need for high airflow and pressure.
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