Bearingless Water Mill-Type Liquid Flowmeter

Abstract

This paper is concerned with a study of a liquid flowmeter by applying the principle of the bearingless windmill-type gas flowmeter already developed by the authors. The float equipped with a water mill is floating on the surface of liquid in a bell-type enclosure, and the position of the float is held on the center by a magnetic attraction. Since the liquid is Newtonian, the friction between the float and the liquid is expected to be negligible when the relative speed is near zero. Thus the flowmeter enables a extremely flow flow rate measurement. The rotating speed of the water mill by a liquid flow is detected by means of opto-electronic counting procedures without any friction on the rotation, and from which the flow rate of a liquid is obtained. The flowmeter proposed here shows a linearity over the wide range of the flow rate from 1×10^-7 to 5×10^-5m³/s.