IMPROVEMENTS IN PITOT TUBE TYPE FLOW MEASURING DEVICES AND METHODS OF MOUNTING SAME IN LIQUID/GAS TWO-PHASE OR MULTI-PHASE SYSTEMS

This invention relates to an improved pitot tube type flow measuring instrument for use in pipes and other conduits characterized by a generally diamond-shaped sensor portion constituting a bluff body for splitting the flow that includes at least a large-radiused leading edge in which three or more impact ports are located, a pair of planar portions diverging rearwardly from the leading edge to a transversely-spaced pair of much shorter-radiused side edges that cooperate therewith and the downstream-facing portion of the bluff body to define flow separation zones capable of stabilizing the flow coefficient over a broad range of flow conditions provided that the distance separating them is at least five times either of their radii. The invention further includes the unique method of mounting the probe in two-phase or multi-phase flowing systems where one of the fluids is a liquid and another a gas that calls for tilting the axis of the sensing portion thereof at an angle to the horizontal such that pools of the liquid are trapped in one end or the other depending upon whether the gaseous constituent is hot or cold.