Cryogenic fluid flow meter includes deformable tube within gaseous envelope deforming in response to flow rate

摘要

The deformable tubes is enclosed in an outer gas envelope providing insulation for the critical tube elements. The flowmeter comprises deformable tubes (1,2,3) such that the measurement of their deformation allows a determination of the rate of flow of fluid circulating under pressure inside them. The tubes are situated within a tubular envelope (7) and the space between the tubes and the envelope is filled with a gas which condenses at a temperature slightly higher than that of the cryogenic liquid, such that the space is thus placed under vacuum. If the cryogenic liquid is nitrogen, an appropriate gas is carbon dioxide at a pressure of 200mbars above atmospheric pressure. The tubes are able to deform freely under vacuum, enabling measurement of the rate of flow of the cryogenic liquid.