When it comes to freezing IQF food products, there are several different methods that can be used. However, the most important thing is achieving proper fluidization.

Fluidization means making your product act like a fluid in the freezer so that it can be separated easily. It also helps to maintain a higher hygienic quality for your IQF food products.

Circulating Fluidization

Fluidization is the process of separating and individually freezing different units of product, resulting in the highest quality and best looking frozen product. In order to achieve this, processors must understand how each type of product requires a specific type of fluidization to freeze it properly.

In IQF, each unit of product must be separated in order to keep the nutrients and texture intact. Therefore, it is essential for processors to learn how to adjust fluidization based on the type of product such as water content, weight, shape, brix level, fragility and so forth.

This process of separating the product from one another helps to maintain the separation and also reduces dehydration thereby keeping the quality of the product at its best. With proper fluidization, it is possible to keep each unit of product at its optimal condition and speed up the freezing process.

There are three main types of fluidization used in IQF Freezer- circulating fluidization, bubbling fluidization and fixed bed fluidization. Each type of fluidization works in a different part of the freezer and each has its own advantages.

Circulating fluidization is the most common form of fluidization and it is used to create the first crust-freezing stages in the freezer. This type of fluidization allows for the products to be easily lifted from the freezer bed, and it can also help with core-freezing as well.

Unlike the other two types of fluidization, circulating fluidization does not require any mechanical device to induce it and it is very easy to maintain. In fact, it is recommended to use this type of fluidization in the first stage of the IQF freezing process because it is highly effective and will allow for the maximum efficiency of the system.

In contrast, the other two types of fluidization are not as effective and they may require more complex mechanical devices to induce them. This is because these types of fluidization are more difficult to control and maintain.

This can be due to the fact that a large number of components are involved and there are multiple moving parts that can cause friction and wear. This can affect the quality of the product and can even damage the equipment. This is why it is important for processors to be able to control the fluidization process from the outside of the freezer.

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Bubbling Fluidization

The fluidization of iqf freezers depends on many different factors. The type of fans, the design of the bedplate and the overall design of the IQF freezer play crucial roles in creating the right fluidization for each product unit. In addition, the aerodynamics of the Fluidized IQF Freezer body must be taken into consideration as well.

Besides these factors, the physics of bubble formation is also important to understand how bubbling fluidization works with iqf freezers. This includes the size of the bubbles, their distribution and velocity. Understanding these properties can help in modeling the mass-transfer behavior of a bubble phase, as well as the impact of the expansion of the fluidized bed on reaction conversion.

Bubbles can be measured using capacitance probes positioned vertically above the bubbles in the fluidized bed. This allows for the determination of the temporal local changes in solid concentration induced by rising bubbles.

In addition to the bubble sizes, a variety of other properties of the bubbles in a fluidized bed can be investigated, such as their shape, distribution and velocity. These properties are vital for understanding the bubble phase of a fluidized bed and its influence on the reaction behavior in scale-up.

A series of measurements was performed in three fluidized bed plants having diameters of 0.1 m (FB100), 0.4 m (CFB400) and 1 m (FB1000). Superficial gas velocities in the range of 0.18 to 1.4 m/s were used with a mass flow controller to control the bubble velocities and distribution of bubbles in the bed.

As shown in Figure 3, bubble size and velocity vary with the height of the bubbles, which is influenced by the flow rate. As the flow rate increases, the bed height progressively increases, as does the volume of the bubbles. This leads to higher transport of heat and mass in the bubbles.

Moreover, increasing superficial gas velocity also increased the number of vertical stretched bubbles, which lowered pressure fluctuations in the fluidized bed. These vertical stretched bubbles are similar to bubbles in the emulsion phase and have a large horizontal size compared to their vertical dimension.

Fixed Bed Fluidization

In the iqf freezer, products are frozen by fluidization in air at very low temperature. In this procedure, the size of the product to be frozen is limited by the energy needed to produce the required air velocity for the fluidization process.

The process of fluidization can be categorized into three different types: circular, bubbling, and fixed bed fluidization. Circulating fluidization is the most common type of fluidization, and it is used in the first stage of freezing the products in an iqf tunnel. It is also known as semi-fluidized, because the extremely strong air inflow lifts the product units from the bed plate.

Another important part of the fluidization process is gas and particle mixing. This is a complex process of heat transfer that controls the temperature differences between the particles and the bubbles, as well as between the gas and the particles. It is a very complicated process and it can be difficult to understand the exact processes that are taking place.

This mixing process is especially intensive in large fluidized beds and at high fluidization velocities. As a rule, the axial gas-to-particle diffusion coefficient in a fluidized bed is quite small, ranging from 0.1 to 1 m2/s, while the lateral one is much higher, ranging from 10 to 50 m2/s.

However, the mixing process in the axial direction is much more intensive than the lateral one, mainly due to the difference in gas-to-particle heat transfer. This is a result of the fact that gas in the bubbles is at a much lower temperature than the gas inside the particles, and this heat difference can be increased by a variety of mechanisms.

In an iqf freezer, these processes are controlled by several factors such as the fan type and design of the bedplate, as well as the overall design of the Tunnel Quick-freezing Machine. In addition to the pressure drop achieved on the bedplate, these factors play an important role in the creation of fluidization, as it determines the shape of the bubbles and the speed at which they break up into smaller fragments.

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Optimal Fluidization

In the process of freezing food items, a key aspect is how the product is separated. This separation is achieved through a type of freezer called a fluidized iqf freezer.

A fluidized iqf freezer is designed to freeze different types of products with high efficiency and optimum quality. It is an efficient way of preserving foods such as fruits, vegetables, meats, fish and eggs. It is also effective for the production of ice cream.

This type of freezer works by directing an upward air stream that will separate the products from one another. This type of freezing process is popular among IQF food processors because it results in a loose, premium product. It is also easier to work with than a larger, frozen lump of product.

The way that the products are positioned inside of the freezer determines how well they will be able to separate during the freezing process. This is why the freezer must be designed with a high level of aerodynamics.

Fortunately, there are many ways to optimize the fluidization of the products in an iqf freezer. This includes the design of the iqf tunnel, as well as the type of fans used within the system.

Variable speed control of all the fans and belts can allow on-the-fly optimization of the air flow conditions in the freezer, allowing for maximum freezing efficiency. This makes it easy to control the fluidization process and ensure a great outcome for all your different products.

Some of the factors that can affect the fluidization of the products are the size and distribution of holes in the bedplates as well as the overall design of the iqf tunnel. The OctoFrost(tm) IQF tunnel is designed with thicker bedplates to allow for bigger holes that will help in achieving the best possible pressure drop and a higher degree of control over the fluidization.

In order to obtain optimal fluidization, the iqf tunnel should use vane axial fans that are capable of efficiently using frequency converters. This allows for 100% controlled fan speeds, which can be increased or decreased depending on the product.