Throughout the U.S., certain coal-fired power plants are being converted to operate on natural gas. Natural gas prices continue to fall, and the fuel is considered to be more environmentally-friendly than coal. For power plant operation, burning natural gas emits about half as much carbon dioxide as coal.
The new owner of a coal-fired power plant on the US East Coast recently converted its facility to operate on natural gas. The heart of the upgraded plant is a state-of-the-art gas turbine with the capacity to provide more than 650 MW of electrical power to the grid. To keep the building at a comfortable temperature, reliable industrial duty high-quality fans were needed to remove heat produced by the large turbine. When searching for exhaust fans that could provide good ventilation and meet sound-level specifications, the new owner turned to Easton Industrial Air to design and supply them.
To keep the building comfortable, the exhaust fans had to provide enough air flow to extract the heat produced by the turbine. However, noise management was the primary constraint. The owner’s primary concern was to ensure the fans met local codes for noise levels at the property boundary.
Because the exhaust fans would be installed on the roof, wind loading was another concern. According to the owner’s specification, the roof ventilators were to withstand wind speeds of 100 mph. In addition, the fans had to be self-supporting meaning the owner required the fan/silencer to meet this wind load criteria without the use of guy wires. Typically, fans that extend more than 8 feet above the roof deck must be secured with guy wires. However, fans that satisfy the owner’s design specifications would extend nearly 12 feet above the roof.
To meet the fan performance criteria and satisfy the sound, wind loading, and structural design requirements, Easton supplied several direct-drive VJ Vane-axial fans with patented weatherproof silencers. The VJ fan is quiet, which is why it was chosen. The “J” type propeller is the heart of this Vane-axial fan. A unique feature of this fan is that the angle of the blades can be adjusted manually or by using a blade adjusting tool allowing for future flow changes. Easton’s engineers designed the fans—the largest of which was 42 inches—to withstand wind speeds of up to 110 mph without guide wires.