The present invention relates to gas flow diverters.
Gas flow diverters are employed to direct the flow of hot gases delivered through ductwork. A gas flow diverter is typically positioned at a junction at which two passageways diverge, to direct the flow of gases in the ductwork at the junction. For example, a diverter may be used to direct hot gases flowing from a turbine when the gases reach a junction, at which they could flow through one passageway to a heat recovery steam generator or through the other to an exhaust stack.
Gas flow diverters typically include a housing which has two ports which open onto the two passageways, and which defines a junction space between the two ports. A diverter blade is rotatably mounted in the housing to pivot through the junction space between a first position, in which the blade closes one of the ports, and a second position, in which the blade closes the other port.
Often, when the diverter blade is in one of the two positions, the gas must flow around a sharp corner at the junction, causing turbulent flow which results in a deleterious reduction in pressure head. To smooth the airflow and reduce turbulence, turning vanes have been utilized in some diverter assemblies. These vanes are rotatably mounted at the corner about which the gases flow, and include a drive mechanism to rotate the vanes out of the way of the rotating diverter blade. If the drive mechanism which rotates the turning vanes should fail and the diverter blade should continue to rotate, the diverter blade may strike the turning vanes, causing damage to the diverter.