What Is a Centrifugal Fan?
Centrifugal fans, also known as “squirrel cage fans,” are types of centrifugal blowers with fan wheels that have numerous blades arranged in a circular pattern between two opposing rims. These fans operate by forcing air outward through centrifugal force, efficiently directing air to desired locations via a connected hose.
These fans, encased in metal or other materials for blade protection, differ from propeller-type fans by their ability to focus and discharge air from a single point. Their design versatility makes them suitable for a wide range of ventilation purposes.
Uses of Centrifugal Fans
Centrifugal fans are utilized across various industries due to their adaptable design, which includes adjustments to the diameter and height of the fan wheel and configurations like single-side and double-side suction. Primary applications include:
1. Clean Rooms in Semiconductor Manufacturing Facilities
Centrifugal fans are used in clean rooms for circulating highly purified air. They operate as local cooling devices within enclosed systems, avoiding disruption of controlled air environments.
2. Range Hoods
In multi-unit residences, centrifugal fans are commonly used in range hoods to exhaust air and smoke through piping to the exterior of buildings, offering efficient air redirection.
Principles of Centrifugal Fans
Centrifugal fans function through the rapid rotation of a cylindrical array of blades inside a spiral-shaped casing, effectively expelling air through an outlet. Their design allows for stable, high-speed rotation, achieving significant airflow.
Types of Centrifugal Fans
1. Material of Fan Wheel Blades
Blade materials range from plastic for smaller fans to steel sheets or aluminum for larger ones. The attachment method of the blades varies based on fan size and operating environment.
2. Inlet Type
Options include single-suction, where air is drawn from one side, and double-suction, where air intake occurs from both sides, chosen based on installation requirements.
3. Bearing Arrangement
Centrifugal fans come in single-support and double-support types, depending on bearing arrangements and intended use.
4. Additional Considerations
Variations include double-type fans with two blade wheels connected to one motor, different air outlet orientations, and horizontal or vertical rotation axes.
With these diverse configurations, centrifugal fans can be customized for various applications, airflow requirements, and installation constraints within different devices and machinery.