TYPES OF FANS USED IN IQF EQUIPMENT AND TECHNOLOGY
There are many different manufacturers of Iqf equipment on the market but very few that contributed with innovative thinking and solution to the industry. It is truly a science to set up and balance all the parts and elements of an Iqf freezer in order to achieve the best freezing result.
The fans are an important part of the whole freezer construction and the role they play is crucial for achieving true fluidization of the product along each freezing zone.
Type of fans
The fans provide the air for ventilation inside an Iqf tunnel freezer. The rotor of the fans receives energy from the rotating shaft and transmits it to the air.
There are different types of fans, and each is suitable for certain equipment. What differentiates them is the method used to move the air inside the tunnel freezer and the system pressure they operate against. In order to make a selection we need to look at the volume flow rate, pressure, material, space limitation and not at least efficiency.
There are 2 main categories of fans: centrifugal flow and axial flow. In centrifugal flow the airflow changes direction twice – once when entering and once when exiting while in axial flow the air enters and leaves the fan with no change in direction.
Centrifugal flow
The major types of centrifugal fans are radial, forward curved and backward curved. The radial, backward fans are the most commonly used fans for Iqf equipment and they are more efficient than forward-curved fans for this kind of machinery because the changes in static pressure do not overload the motor.
Axial flow
The major types of axial fans are vane axial, tube axial and propeller. Innovative Iqf equipment and technologies such as the OctoFrost™ uses vane axial fans because the design of this fans ensures better energy efficiency. The vane axial fans have a wheel inside a cylindrical housing, with close clearance between the blade and the housing, to improve the airflow efficiency. Also, the vane axial has guide vanes that direct and straighten the airflow, thus improving the overall efficiency. Vane axial fans are usually the most energy efficient fans.
Efficiency and Design
The efficiency of the fans differs a lot from one fan design to another.
The design of the fans makes a huge difference in the efficiency result and we see this in the OctoFrost™ Iqf tunnel freezer, the most efficient Iqf tunnel on the market. Each fan type has a different design but the designs are usually standard. The OctoFrost™ though, uses vane axial fans that are custom made both in the design of the blade and inside the fans. In addition, the OctoFrost™ fans offer the possibility to change the frequency due to the frequency convertors used on each fan, which means that you can run the fans at different speeds - a highly important feature for food processors because they can adjust the fans speed according to the product they are freezing.
The OctoFrost™ fans never need to run at more than between 75% - 80% fan speed even though there is more than enough total motor power.
For a high performant equipment, the fans alone cannot guarantee premium quality Iqf frozen products, but only in combination with other elements of the freezer. For a good circulating airflow though, energy efficient fans in Iqf equipment can be a major asset.