Loading patent…
AssigneeNordisk Ventilator Co. A/S
InventorsOle Roslyng, Niels Erik Friis Dam
Estimating the term…
The stall condition occurring in the unstable working range of an axial flow fan or compressor arranged in an air duct is detected by measuring the pressure difference between the total air pressure acting in a direction opposite to the direction of revolution of the fan wheel and a reference pressure corresponding substantially to the static pressure at the wall of the air duct in the same radial measuring plane. The detector device comprises first and second pressure measuring probes of an open tubular configuration for measuring said total pressure and reference pressure, respectively, and means for detecting the difference between the pressure values measured thereby, said probes being designed and arranged in the air duct so that the flow conditions around them are equal in the stable working range of the fan or compressor.
A method of detecting the stall condition of an axial flow fan or compressor arranged in an air duct, comprising the step of measuring the pressure difference between the total air pressure acting in a direction opposite to the direction of revolution of the fan wheel and a reference pressure corresponding substantially to the static pressure at the wall of the duct in substantially the same radial measuring plane.
A device for detecting the stall condition of an axial flow fan or compressor arranged in an air duct comprising first and second pressure measuring probes of an open tubular configuration for measuring the total air pressure acting in a direction opposite to the direction of revolution of the fan wheel and a reference pressure corresponding substantially to the static pressure at the wall of the duct in substantially the same radial measuring plane, respectively, which probes are designed and arranged in the air duct so that the flow conditions around them are equal in the stable working range of the fan, and means for detecting the difference between the pressure values measured by said probes.
Dependencies are inferred from the claim text.