Start-up Procedures and Operational Process for Boiler Equipment Fans

Start-up Procedures and Operational Process for Boiler Equipment Fans

During the operation of boiler equipment fans, soundproof enclosures are frequently employed. These enclosures can be fabricated in various shapes depending on the type and size of the fan. They are fitted over the air inlets and outlets of the Schladro fan, as well as the access door covers, with all other openings sealed. An exhaust duct is installed at the top of the enclosure to allow heat dissipation from the running motor and to contain the primary source of vibration The fan unit is sealed within the centrifugal fan chamber, preventing the transmission of noise. The air inlet duct must be installed within a sealed fan enclosure to facilitate heat dissipation from the fan, motor and housing. Equipped with a variable-frequency motor, the system utilises variable-frequency starting and operation; whilst this entails a higher initial purchase cost, it offers lower running costs. Boiler equipment fans require airflow adjustment, with a range of 0–60 Hz, making them suitable for fluctuating operating conditions. Some customers design systems requiring the fan to start more than 10 times, which is undoubtedly a challenge for fixed-frequency motors. Excessively high starting currents often lead to insulation deterioration. Boiler equipment fans are equipped with standard fixed-frequency motors utilising star-delta or automatic coupling step-down starting. This is an economical and straightforward method for starting boiler equipment fans. Once the fan has started, the air damper must be closed gradually. Once the boiler fan has reached its rated speed, the air damper is gradually opened as the medium temperature rises, until it is fully open. Here, whilst the design parameters of the boiler fan and its supporting motor are based on high-temperature operation, during the initial stages of the fan’s operation, the gas within the duct is generally at room temperature and has a high molecular density; consequently, the initial load on the boiler fan increases per unit volume. The function of the damper is not only to regulate the airflow but also to prevent overcurrent.