Abstract: A fluidic oscillator for a shunt flowmeter for measuring gas flow through a pipeline, comprises three sections arranged in series and providing a generally U-shaped flow path through the oscillator. The first section has an inlet end connectable to an outlet port in the pipeline and leading to a main fluid nozzle communicating with an interaction chamber, diverging sidewalls of the flow path extending downstream of the interaction chamber, and feedback loops extending from the diverging sidewalls to control nozzles at the interaction chamber. The second section is juxtaposed to the first section to return the flow to the pipeline and has an outlet end connectable to a return port in the pipeline. The second section includes diverging sidewalls terminating in a flow restriction adjacent the outlet end, and a flow-splitter body physically dividing the flow.

Abstract: Apparatus is provided for the flow control of the flue gas to combustion air ratio in a reversible regenerative heating system of the type comprising a pair of regenerators, a first line 7 for supplying air to the regenerators, a second line 8 for removing flue gas from the regenerators, and valves 9,10 respectively for controlling the flow rate of air in the first line 7 and the flow rate of the flue gas in the second line 8. The apparatus comprises a third line 21 adapted to provide a slave flow of fluid proportional to the flow rate of the flue gas, thermistor type anemometers 17 and 18 for sensing the flow rates of combustion air and fluid and a ratio controller 24 for adjusting the flue gas damper valve 10 in accordance with the flow rates so sensed to maintain the ratio of the flue gas to combustion air at a predetermined ratio.