XinFeng Classroom | Ventilator Series: CHR Shell-Less Centrifugal Ventilator

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CHR Shell-Less Centrifugal Fan Product Specifications

The CHR series centrifugal fans without a volute housing are typically designed for direct motor connection. This configuration not only eliminates energy loss from belt transmission but also reduces operational costs associated with belt wear. Engineered for economy, efficiency, and space-saving, these fans do not incorporate the volute housing found in conventional centrifugal fans.

Primarily used in air handling units for enclosed spaces or building structures, it provides pressurized air to the entire environment within, allowing ductwork to connect to the air handling unit from any direction. This design saves space by eliminating the need for fan housings, transition sections, and diffusers within the air handling unit.

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 CHR Shell-less Centrifugal Fan Product Features

    Shell-less body, single-suction design, direct motor drive;

The impeller blades feature a backward-curved airfoil design, delivering high efficiency, high pressure head, and low noise. Prior to shipment, all fans undergo testing at operating speeds, with impeller balance precision rated at G6.

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 Applications of CHR Shell-less Centrifugal Fans 

Another primary application of the CHR series shell-less centrifugal fans is forming fan clusters, where multiple shell-less centrifugal fans replace a single large-diameter centrifugal or axial fan.

Since large-diameter centrifugal or axial fans cannot operate at very high speeds, the noise they generate is typically low-frequency noise. Suppressing low-frequency noise is extremely challenging. Cinemas, luxury hotels, and high-end office buildings all invest significant resources to eliminate this stubborn low-frequency noise. The advent of shell-less centrifugal fan clusters has made solving the low-frequency noise problem a breeze.

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Installation and Commissioning of CHR Shell-Less Centrifugal Fans  

1. Before installation, thoroughly verify that the power supply, voltage, frequency, and other specifications match the motor nameplate data as indicated on the fan nameplate.  

2. Prior to operation, inspect all rotating components of the fan. Ensure no parts rub against each other, all fasteners are secure, and the impeller rotates freely when gently pulled.

3. When installing the fan within a fan enclosure or connecting its outlet to ductwork, ensure a secure connection. If using flexible connectors, ensure the interface pipe wall is taut to minimize airflow resistance. When installed within an enclosure, maintain adequate clearance above, below, and on all sides. When connecting external supply ducts, avoid 90° elbows or abrupt expansions/contractions whenever possible. Failure to do so will significantly impact fan performance. Never place ductwork weight on the fan casing. 4. During operation, the impeller rotation direction must match the direction indicated on the fan casing side. If the rotation is incorrect (i.e., reverse), adjust the power supply phase to ensure proper rotation. 5. During operation, the motor's working current must remain within the rated current range. When using variable frequency drives, ensure operation stays within the rated frequency range. Overloading that could burn out the motor is strictly prohibited. To account for motor inrush current, close the main regulating valve in the ductwork before starting the fan. Gradually open the valve after the fan has started. Never operate the fan with both inlet and outlet fully open to prevent power overload.