Device for measuring speed of a fluid flowing in a pipe having a bearing and a hydraulic circuit

摘要

A device to measure speed of a fluid in a pipe. An adjustment and a surface finish are accomplished between a fluid bearing and a hollow tube coupled with a turbine, with friction minimized to a point that it is possible to measure speeds of less than one cm/s which have hitherto been unexplored.

主权项

1. A device for measuring speed of a fluid flowing in a pipe, comprising:
a turbine including multiple blades of external diameter of order of an internal diameter of the pipe; a bearing of fluid bearing type, including, as a moving element, a hollow tube, which is blind on one side and coupled with the blades, as an element which is attached relative to the pipe, a shaft adjusted in the hollow tube and perforated by at least a first channel, as a lubrication fluid inlet channel, and at least a second channel, as a lubrication fluid drainage channel, wherein the first and second channel define a portion of a hydraulic circuit, in which the hydraulic circuit is adapted, when the inlet channel is supplied from outside the pipe by a pressurized lubrication fluid, to cause the pressurized lubrication fluid to circulate simultaneously between the periphery of the shaft and the hollow tube and between an end of the shaft and a base of the hollow tube in a form of a film of thicknesses equal to plays between the perforated shaft and the hollow tube, and is then recovered through the drainage channel, wherein the lubrication fluid film created in this manner and the surface finish of the adjusted walls of the hollow tube and of the shaft are such that the friction generated between the latter is minimal, to such a degree that it is possible for the blades of the turbine to rotate, and therefore for their speed to be measured when a fluid flows in the pipe at speeds of less than one cm/s.